The main neurovascular unit of the Blood Brain Barrier (BBB) consists of a cellular component, which includes endothelial cells, astrocytes, pericytes, microglia, neurons and oligodendrocytes, as well as a non-cellular component resulting from the extracellular matrix. The endothelial cells are the major vital component of the BBB able to preserve the brain homeostasis; these cells are situated along the demarcation line between the bloodstream and the brain. Therefore, an alteration or the progressive disruption of the endothelial layer may clearly impair the brain homeostasis. The proper functioning of the brain endothelial cells is generally ensured by two elements: 1) the presence of junction proteins; 2) the preservation of a specific polarity involving an apical-luminal and a basolateral-abluminal membrane. In view of the above, this review intends to identify the molecular mechanisms underlying BBB function and their changes occurring in early stages of neurodegenerative processes in order to develop novel therapeutic strategies aimed to counteract neurodegenerative disorders.

Recent studies have confirmed that lung microvascular endothelial injury plays a critical role in the pathophysiology of COVID-19. Our group and others have demonstrated the beneficial effects of H2S in several pathological processes and provided a rationale for considering the therapeutic implications of H2S in COVID-19 therapy. Here, we evaluated the effect of the slow-releasing H2S donor, GYY4137, on the barrier function of a lung endothelial cell monolayer in vitro, after challenging the cells with plasma samples from COVID-19 patients or inactivated SARS-CoV-2 virus. We also assessed how the cytokine/chemokine profile of patients’ plasma, endothelial barrier permeability, and disease severity correlated with each other. Alterations of barrier permeability after treatments with patient plasma, inactivated virus, and GYY4137 were monitored and assessed by electrical impedance measurements in real-time. We present evidence that GYY4137 treatment reduced endothelial barrier permeability after plasma challenge and completely reversed the endothelial barrier disruption caused by inactivated SARS-CoV-2 virus. We also showed that disease severity correlated with the cytokine/chemokine profile of the plasma but not with barrier permeability changes in our assay. Overall, these data demonstrate that treatment with H2S-releasing compounds has the potential to ameliorate SARS-CoV-2–associated lung endothelial barrier disruption.

Life-threatening inflammatory conditions such as acute respiratory distress syndrome or sepsis often go hand in hand with severe vascular leakage. During inflammation, endothelial cell integrity and intact barrier function are crucial to limit leukocyte and plasma extravasation. Prostaglandin D₂ (PGD₂) is a potent inflammatory lipid mediator with vasoactive properties. It has been suggested that PGD^­₂ is involved in the regulation of endothelial barrier function; however, it is unclear whether this is also true for primary human pulmonary microvascular endothelial cells. Furthermore, as PGD₂ is a highly promiscuous ligand, we set out to determine which receptors are important in human pulmonary endothelial cells. In the current study, we found that PGD₂ and the DP1 agonist BW245c potently strengthened pulmonary and dermal microvascular endothelial cell barrier function and protected against thrombin-induced barrier disruption. Yet surprisingly, these effects were mediated only to a negligible extent via DP1 receptor activation. In contrast, we observed that the EP4 receptor was most important and mediated the barrier enhancement by PGD₂ and BW245c. These data demonstrate a novel mechanism by which PGD₂ may modulate inflammation and emphasizes the role of EP4 receptors in human endothelial cell function.

Pericytes are increasingly recognized as being important in the control of blood-brain barrier permeability and vascular flow. Research on this important cell type has been hindered by widespread confusion regarding the phenotypic identity and nomenclature of pericytes and other perivascular cell types. In addition, pericyte heterogeneity and mouse-human species differences have contributed to confusion. Herein we summarize our present knowledge on the identification of pericytes and pericyte subsets in humans, primarily focusing on recent findings in humans and nonhuman primates. Precise identification and definition of pericytes and pericyte subsets in humans may help us to better understand pericyte biology and develop new therapeutic approaches specifically targeting disease-associated pericyte subsets.

Dynamic contrast-enhanced MRI (DCE-MRI) is increasingly used to quantify and map the spatial distribution of blood-brain barrier (BBB) leakage in neurodegenerative disease, including cerebral small vessel disease and dementia. However, the subtle nature of leakage and resulting small signal changes make quantification challenging. While simplified one-dimensional simulations have probed the impact of noise, scanner drift, and model assumptions, the impact of spatio-temporal effects such as gross motion, k-space sampling and motion artefacts on parametric leakage maps has been overlooked. Moreover, evidence on which to base the design of imaging protocols is lacking due to practical difficulties and the lack of a reference method. To address these problems, we present an open-source computational model of the DCE-MRI acquisition process for generating four-dimensional Digital Reference Objects (DROs), using a high-resolution brain atlas and incorporating realistic patient motion, extra-cerebral signals, noise and k-space sampling. Simulations using the DROs demonstrated a dominant influence of spatio-temporal effects on both the visual appearance of parameter maps and on measured tissue leakage rates. The computational model permits a greater understanding of the sensitivity and limitations of subtle BBB leakage measurement and provides a non-invasive means of testing and optimising imaging protocols for future studies.

The present study aims to evaluate the ability of peonidin and petunidin-3-glucoside (Peo and Pet-3-glc) and their metabolites (vanillic acid; VA and methyl-gallic acid; MetGA), to prevent monocyte (THP-1) adhesion to endothelial cells (HUVECs), and to reduce the production of VCAM-1, E-selectin and VEGF in a stimulated pro-inflammatory environment, a pivotal step of atherogenesis. Tumor necrosis factor-α (TNF-α; 100 ng mL-1) was used to stimulate the adhesion of labelled monocytes (THP-1) to endothelial cells (HUVECs). Successively, different concentrations of Peo-3-glc and Pet-3-glc (0.02, 0.2, 2 and 20 µM) and VA and MetGA (0.05, 0.5, 5 and 50 µM) were tested. After 24 h, the production of VCAM-1, E-selectin and VEGF was quantified by ELISA kits, while the adhesion process was measured spectrophotometrically. Peo-3-glc and Pet-3-glc (from 0.02 to 20 µM) significantly (p<0.0001) decreased THP-1 adhesion to HUVECs at all concentrations (-37%, -24%, -30% and -47% for Peo-3-glc; -37%, -33%, -33% and -45% for Pet-3-glc). VA, but not MetGA, reduced the adhesion process at 50 µM (-21%; p<0.001). At the same concentrations, a significant (p<0.0001) reduction of E-selectin, but not VCAM-1, was documented. In addition, anthocyanins and their metabolites significantly decreased (p<0.001) VEGF production. The present findings suggest, that while Peo-3-glc and Pet-3-glc, but not their metabolites, reduced monocyte adhesion to endothelial cells through suppression of E-selectin production, VEGF production was reduced by both anthocyanins and their metabolites suggesting a role in regulation of angiogenesis.

Brain capillary endothelial cell(s) (BECs) have numerous functions including their semipermeable interface-barrier (transfer and diffusion of solutes), trophic (metabolic homeostasis), tonic (vascular hemodynamics), and trafficking (vascular permeability, coagulation, and leukocyte extravasation) functions to provide brain homeostasis. BECs also serve as the brain’s sentinel cell of the innate immune system and are capable of antigen presentation. In metabolic syndrome (MetS) there are two regions resulting in proinflammatory signaling of BECs. Namely, visceral adipose tissue depots supplying excessive peripheral cytokines/chemokines (pCC) and gut microbiota dysbiotic regions supplying excessive soluble lipopolysaccharide (sLPS), small LPS-enriched extracellular vesicle exosomes (lpsEVexos), and pCC. This dual signaling of BECs at their receptor sites results in BEC activation and dysfunction (BECact/dys) and neuroinflammation. sLPS and lpsEVexos signal BECs toll-like receptor four, which then signals translocated nuclear factor kappa B (NFkB). Translocated NFkB promotes the synthesis and secretion of BEC proinflammatory cytokines and chemokines. Specifically, the chemokine CCL5 (RANTES) is capable of attracting microglia cells to BECs. BEC neuroinflammation activates perivascular space(s) (PVS) resident macrophages. Excessive phagocytosis by reactive resident PVS macrophages results in a stagnation-like obstruction, which along with increased capillary permeability due to BECact/dys could expand the fluid volume within the PVS to result in enlarged PVS (EPVS). Importantly, this remodeling may result in pre- and post-capillary EPVS that would contribute to their identification on T2-weighted MRI, which are considered to be biomarkers for cerebral small vessel disease.

The Hedgehog (Hh) signaling pathway plays an important role in embryonic and postnatal vascular development and in maintaining the homeostasis of organs. Under physiological conditions, Sonic Hedgehog (Shh), a secreted protein belonging to the Hh family, regulates endothelial cell growth, promotes cell migration, and stimulates the formation of new blood vessels. The present review highlights recent advances made in the field of Shh signaling in endothelial progenitor cells (EPCs). The canonical and non-canonical Shh signaling pathways in EPCs and endothelial cells (ECs) related to homeostasis, Shh signal transmission by extracellular vesicles (EVs) or exosomes containing single-strand non-coding miRNAs, and impaired Shh signaling in cardiovascular diseases are discussed. As a promising therapeutic tool, the possibility of using the Shh signaling pathway for the activation of EPCs in patients suffering from cardiovascular diseases is further explored.

Evidence supports an association between low magnesium (Mg) intake and coronary heart disease and between Mg intake and endothelial function. The aim of this study was to assess the effect of one week of Mg supplementation on endothelial function, assessed by flow mediated dilatation (FMD). Nineteen healthy men and women completed this cross-over pilot study in which participants were randomised to take an over-the-counter magnesium supplement for one week or to follow their usual diet. Weight, FMD and blood pressure (BP) were taken on completion of each intervention and 24hour urine collections and blood samples were taken to assess compliance. Baseline serum Mg was within normal range for all participants. Urinary Mg and urinary magnesium-creatinine ratio (Mg/Cr) significantly increased between interventions, (p = 0.03, p = 0.005 respectively). No significant differences in FMD or BP were found between the interventions. A significant negative correlation was seen between age and FMD (r = -0.496, p = 0.031). When adjusted for age, saturated fat was negatively associated with FMD (p = 0.045). One week of Mg supplementation did not improve FMD in a healthy population.

Evidence supports an association between low magnesium (Mg) intake and coronary heart disease and between Mg intake and endothelial function. The aim of this study was to assess the effect of one week of Mg supplementation on endothelial function, assessed by flow mediated dilatation (FMD). Nineteen healthy men and women completed this cross-over pilot study in which participants were randomised to take an over-the-counter magnesium supplement for one week or to follow their usual diet. Weight, FMD and blood pressure (BP) were taken on completion of each intervention and 24hour urine collections and blood samples were taken to assess compliance. Baseline serum Mg was within normal range for all participants. Urinary Mg and urinary magnesium-creatinine ratio (Mg/Cr) significantly increased between interventions, (p = 0.03, p = 0.005 respectively). No significant differences in FMD or BP were found between the interventions. A significant negative correlation was seen between age and FMD (r = -0.496, p = 0.031). When adjusted for age, saturated fat was negatively associated with FMD (p = 0.045). One week of Mg supplementation did not improve FMD in a healthy population.

Magnesium (Mg) deficiency may be a catalyst in the process of endothelial dysfunction, an early event in the pathogenesis of atherosclerosis. The aim was to determine the acute effect of an oral Mg supplement compared to control on endothelieal function assessed by flow-mediated-dilatation (FMD). Nineteen participants (39 years, body mass index (BMI) 22.9kg/m2) completed this randomised cross-over study. Blood pressure (BP) and FMD were measured and blood samples taken before participants drank 200ml water with or without an over the counter Mg supplement (450mg and 300mg for men and women). Measurements were repeated at 60 and 120 minutes. There was a statistically significant two-way interaction between treatment and time on serum Mg (p = .037). A difference of -0.085mm in FMD was observed 60 minutes post drink in the control group compared to baseline FMD, and no difference was observed in the supplement group compared to baseline. Despite the non-significant interaction between treatment and time on FMD, the difference seen in the control group and the lack of change in the supplement group at 60 minutes post-drink suggests that Mg may attenuate the reduction in FMD post-prandially.

Severe Covid-19 disease is associated with endothelial infection, viraemia, and multi-organ dysfunction. The process through which SARS-CoV2 causes severe disease is yet to be determined. Here, we propose that in severe Covid-19 infection, SARS-CoV2 reaches the host bloodstream by infecting endothelial cells through their basal surface. This occurs, independently of ACE2, through CD147, a putative SARS-CoV2 receptor. The pathway proposed here encourages research on the mechanisms mediating endothelial cell infection in Covid-19.

The release of nanomolar concentrations of nitric oxide (NO) by endothelial cells (EC), via activation of constitutive NO synthase (eNOS), represents the pre-requisite for the vaso-protective role of vascular endothelium. On the other hand, exaggerated release of NO as a consequence of activation of inducible NO synthase (iNOS), leads to endothelial dysfunction and, at the late stages, to the development of atherothrombosis. Oxidyzed LDLs (OxyLDL) represent the major candidate to trigger biomolecular processes accompanying endothelial dysfunction and vascular inflammation leading to atherosclerosis development though the pathophysiological mechanism still remains to be elucidated. Here, we summarize recent evidence suggesting that oxyLDL produce significant impairment in the balance in the eNOS/iNOS machinery, downregulating eNOS via HMGB1-TLR4-Caveolin-1 pathway. On the other hand, a sustained activation of the scavenger receptor LOX-1 leads to NFkB activation which, in turn, increases iNOS, leading to EC oxidative stress. Finally, these events are associated to reduced protective autophagic response and accelerated apoptotic EC death which activates atherosclerotic development. Taken togheter, these informations shed new light into the pathophysiological mechanisms of oxy-LDL-related impairment of EC functionality and open new perspective in atherothrombosis prevention.

Placental hypervascularization has been reported in pregnancy-related pathologies such as gestational diabetes mellitus (GDM). Nevertheless, the underlying causes behind this abnormality are not well understood. In this study, we addressed the expression of SUCNR1 (cognate succinate receptor) in human placental endothelial cells and hypothesized that succinate-SUCNR1 axis might play a role in the placental hypervascularization reported in GDM. We measured significantly higher succinate levels in placental tissue lysates from women with GDM relative to matched controls. In parallel, SUCNR1 protein expression was upregulated in GDM tissue lysates as well as in isolated diabetic fetoplacental arterial endothelial cells (FpECAds). A positive correlation of SUCNR1 and vascular endothelial growth factor (VEGF) protein levels in tissue lysates indicated a potential link between succinate-SUCNR1 axis and placental angiogenesis. In our in-vitro experiments, succinate prompted hallmarks of angiogenesis in human umbilical vein endothelial cells (HUVECs) such as proliferation, migration and spheroid sprouting. These results were further validated in fetoplacental arterial endothelial cells (FpECAs), where succinate induced endothelial tube formation. VEGF gene expression was increased in response to succinate in both HUVECs and FpECAs. Yet, knockdown of SUCNR1 in HUVECs led to suppression of VEGF gene expression and abrogated the migratory ability and wound healing in response to succinate. In conclusion, our data underline SUCNR1 as a promising metabolic target in human placenta and as a potential driver of enhanced placental angiogenesis in GDM.

Inflammation associated endothelial dysfunction represents a pivotal contributor to atherosclerosis. Increasingly evidence has demonstrated that interleukin 1 receptor (IL1-R) / toll-like receptor (TLR) signaling participated in the development of atherosclerosis. Previous studies indicated the therapeutic potential of anti-inflammatory therapy in anti-atherosclerosis. The present study examined the effect of IL-1R-associated kinase 1 and 4 inhibitors (IRAK1/4i) in regulating endothelial dysfunction. IRAK1/4i showed little endothelial toxicity at concentrations from 1 to 10 μM. Inhibition of IRAK1/4 alleviated endothelial activation induced by LPS in vitro evidenced by attenuated monocyte adhesion to the endothelium. Mechanistically, blockade of IRAK1/4 ameliorated the transcriptional activity of NF-κB. Taken together, our findings demonstrated that dual inhibition of IRAK1 and IRAK4 attenuates endothelial dysfunction, suggesting pharmaceutical inhibition of IRAK1/4 might be a potential strategy to combat endothelial dysfunction and atherosclerosis.

Aim: Evaluation of role of supplementation of omega-3 polyunsaturated fatty acids on endothelial function in patients with metabolic syndrome. Methods: Total of 80 patients with metabolic syndrome were enrolled to two groups. We evaluated endothelial function in subjects before and after three-month treatment with omega-3 polyunsaturated fatty acids in dose 2.4g daily (800mg 3 times a day) vs placebo. Using the Endo-PAT2000 device (Itamar Medical Ltd. Caesarea, Israel), reactive hyperemia index – a parameter of endothelial function and augmentation index– a parameter of arterial stiffness were measured. Plasmatic level of glutation peroxidase, homocysteine, apolipoprotein B and lipoprotein (a) were also evaluated. Results: The average values of reactive hyperemia index before the treatment with n-3PUFA was 1.62 ± 0.42 , whereas 1.96 ± 0.62 at the end of the study (p<0.005). Augmentation index changed from 14.66 ± 19.55 to 9.21 ± 15.64 after the treatment (p=0.003). We also observed statistically significant decrease of apolipopotein B (0.94 ± 0.36 vs 1.13 ± 0.35, p = 0.001) and homocysteine (19.31 ± 5.29 vs. 13.78 ± 3.05, p = 0.001) and increase of the glutathion perxidase plasma levels (41.65 ± 8.90 vs. 45.20 ± 8.01), p=0.001. Conclusion: We have observed significant improvement of the endothelial function in subjects with metabolic syndrome treated with omega-3 polyunsaturated fatty acids in dose 2.4g daily.

There is evidence that behavioral risk factors such as western type diet, and life style can predispose to oxidative stress, deficiency in antioxidant status, hyperglycemia, dyslipidemia and increase in inflammation in tissues of various organs: beta cells of the pancreas, LDL receptors in the hepatocytes, endothelium, neurons, osteocytes and gut. Further studies indicate that diets rich in antioxidant flavonoids, omega-3 fatty acids and fiber in foods were inversely associated whereas western-type foods were positively associated with risk of mortality due to cardiovascular diseases (CVDs). One important cause for beneficial effects of diet may be certain foods and nutrients such as vegetables, fruits and whole grains that are rich in fiber and flavonoids, known to produce liters og molecular hydrogen in the gut. It seems that, high-fiber diets, prebiotic and probiotics can produce greater hydrogen, which acts as an antioxidant and may inhibit free radical generation. Recent studies indicate that molecular hydrogen can inhibit hydroxyl and nitrosyl radicals and can directly act as antioxidant in the cells and tissues, which can cause marked decline in oxidative stress and inflammation leading to significant decline in CVDs and metabolic diseases. Clinical and experimental studies indicate that hydrogen therapy such as hydrogen rich water can provide benefits in the management of CVDs and metabolic diseases. Larger studies are necessary to verify the role of hydrogen administration in CVDs.

AIM: The study aims to identify if mutations in the SLC4A11 gene are present in Filipino families affected with Congenital Hereditary Endothelial Dystrophy (CHED). METHODS: This is a family cohort study that investigated the genetic profile of a selected family in Northern Luzon, Philippines, whose members were diagnosed with Congenital Hereditary Endothelial Dystrophy (CHED). A patient who was diagnosed with CHED prior to this study, served as the proband for this family. A detailed family history and a complete ophthalmologic examination were done to each of the family members. A total of six affected members and three unaffected members were included in this study. DNA was isolated from peripheral blood samples of family members, and polymerase chain reaction (PCR) was used to amplify the gene’s entire coding region, (19 exons and 2 putative promoter regions), and finally, the amplified regions were analyzed using DNA sequencing. RESULTS: Consanguinity was not present in the family. Corneal haze was reported to be present since birth or shortly thereafter in all affected patients. Slit-lamp examination showed edematous corneas. Molecular studies of the SLC4A11 gene revealed four novel homozygous point mutations variably present in six affected members as well as three unaffected members. One unaffected family member (I-1) had a novel sense mutation absent in other family members. All affected siblings showed little phenotypic variability. CONCLUSION: This is the first report that gives us a genetic profile of a Northern Luzon family with members affected by CHED. This study supports earlier findings that the mutations in the SLC4A11 gene are not consistently the same among different ethnic groups worldwide, probably due to the disease’s genetic heterogeneity. Our study documented five novel mutations adding to the growing list of mutations probably responsible for acquiring the CHED phenotype. It is possible that there are more novel mutations waiting to be discovered in this hereditary disease. Screening for these specific mutations in other families may prove useful for genetic counseling, prenatal diagnosis and the future development of gene therapy.

Pathologies of the blood brain barrier (BBB) have been linked to a multitude of CNS disorders whose pathology is poorly understood. Cortical spreading depression (CSD) has long been postulated to be involved in the underlying mechanisms of these disease states, yet full understanding remains elusive. This study utilized an in vitro model of the BBB with b.End3 murine endothelial cells to investigate the role of CSD in BBB pathology by characterizing effects of the release of major pronociceptive substances on BBB functional integrity using TEER screening, transcellular uptake, and immunoreactive methods in concert with global proteome and phospho-proteomic approaches. Findings demonstrated relocalization and functional alteration to proteins associated with the cytoskeleton and endothelial tight junctions. Pathologic mechanisms induced by individual substances released during CSD were found to have unique phosphorylation signatures in phospho-proteome analysis, identifying Zona Occludens 1 as a possible pathologic “checkpoint” of the BBB. Utilizing these phosphorylation signatures, possible novel diagnostic methods may be developed for neurological diseases and warrants further investigation.

Angiotensin-converting enzyme 2 (ACE2) is an important player of the renin-angiotensin-aldosterone system (RAAS) in regulating the conversion of angiotensin II into angiotensin (1-7). While expressed on the surface of human cells, such as lung, heart, kidney, neurons, and endothelial cells (EC), ACE2 is the entry receptor for SARS-CoV-2. Here, we would like to highlight that ACE2 is predominant on the EC membrane. Many of coronavirus disease 2019 (COVID-19) symptoms have been associated with the large recruitment of immune cells, directly affecting EC. Additionally, cytokines, hypoxia, and complement activation can trigger the activation of EC leading to the coagulation cascade. The EC dysfunction plus the inflammation due to SARS-CoV-2 infection may lead to abnormal coagulation, actively participating in thrombo-inflammatory processes resulting in vasculopathy and indicating poor prognosis in patients with COVID-19. Considering the intrinsic relationship between EC and the pathophysiology of SARS-CoV-2, EC-associated therapies such as anticoagulants, fibrinolytic drugs, immunomodulators, and molecular therapies have been proposed. In this review, we will discuss the role of EC in the lung inflammation and edema, in the disseminate coagulation process, ACE2 positive cancer patients, and current and future EC-associated therapies to treat COVID-19.

Endothelial disorders are related to various diseases. An initial endothelial injury is characterized by endothelial glycocalyx injury. We aimed to evaluate endothelial glycocalyx injury by measuring serum syndecan-1 concentrations in patients during comprehensive medical examinations. A single-center, prospective, observational study was conducted at Asahi University Hospital. The participants enrolled in this study were 1313 patients who underwent comprehensive medical examinations at Asahi University Hospital from January 2018, to June 2018. One patient undergoing hemodialysis was excluded from the study. At enrollment, blood samples were obtained, and study personnel collected demographic and clinical data. No treatments or exposures were conducted except for standard medical examinations and blood sample collection. Laboratory data were obtained by collection of blood samples at the time of study enrolment. According to nonlinear regression, the concentrations of serum syndecan-1 were significantly related to age (p = 0.016), aspartic aminotransferase concentration (AST, p = 0.020), blood urea nitrogen concentration (BUN, p = 0.013), triglyceride concentration (p < 0.001), and hematocrit (p = 0.006). These relationships were independent associations. Endothelial glycocalyx injury, which is reflected by serum syndecan-1 concentrations, is related to age, hematocrit, AST concentration, BUN concentration, and triglyceride concentration.

Cytokines and chemokines (chemotactic cytokines) are soluble extracellular proteins that bind to specific receptors and play an integral role in the cell-to-cell signaling network, in addition can promote the homing of cancer cells into different organs. We investigated the potential relationship between human hepatic sinusoidal endothelial cells (HHSECs) and several melanoma cell lines for the expression of chemokine and cytokine ligand and receptor expression during invasion of melanoma cells. In order to define the invasion related gene expression differences, we selected invasive and non-invasive subpopulations of cells after co-culturing with HHSECs. In addition, we determined protein expression of the endothelial cells before and after co-culturing with melanoma cell lines originated from primary tumors. Cell lines with increased invasive capacity after culturing with conditioned medium showed a set of receptor genes (CXCR1, IL1RL1, IL1RN, IL3RA, IL8RA, IL11RA, IL15RA, IL17RC, and IL17RD) with significantly different expression. It is very important note, that the IL11RA gene expression level was also significantly increased in primary melanoma tissues with liver metastasis as well. Proteome arrays revealed 15 differentially expressed proteins (including CD31, VCAM-1, ANGPT2, CXCL8, and CCL20) in the hepatic endothelial cells after co-cultured with melanoma cells. Our findings clearly indicate the interaction between liver endothelial- and melanoma cells. Based on our data, we assume that overexpression of the IL11RA gene might has key role in the formation of organ specific metastasis to the liver by primary melanoma cells.

Peripheral nerve injuries pose a major clinical concern world-wide, and functional recovery after segmental peripheral nerve injury is often unsatisfactory, even in case of autografting. Although it is well established that angiogenesis plays a pivotal role during nerve regeneration, the influence of lymphangiogenesis is strongly underinvestigated. In this study, we analyzed the presence of lymphatic vasculature in healthy and regenerated murine peripheral nerves, revealing that nerve autografts contained increased numbers of lymphatic vessels after segmental damage. This led us to elucidate the interaction between lymphatic endothelial cells (LECs) and Schwann cells (SCs) in vitro. We show that SC and LEC secretomes do not influence the respective other cell types’ migration and proliferation in 2D scratch assay experiments. Furthermore, we successfully created lymphatic microvascular structures in SC-embedded 3D fibrin hydrogels in the presence of supporting cells, whereas SCs seemed to exert anti-lymphangiogenic effects when cultured with LECs alone. Here, we describe for the first time increased lymphangiogenesis after peripheral nerve injury and repair. Furthermore, our findings indicate a potential lymph-repellent property of SCs, thereby providing a possible explanation for the lack of lymphatic vessels in the healthy endoneurium. Our results highlight the importance to elucidate the molecular mechanisms of SC-LEC interaction.

The symptoms most commonly reported by patients affected by coronavirus disease 2019 (COVID-19) include cough, fever, and shortness of breath. However, other major events usually observed in COVID-19 patients (e.g. high blood pressure, thrombosis, pulmonary embolism) seem to suggest that the virus is targeting the endothelium, one of the largest organs in the human body. Herein, we report both clinical and preclinical evidence supporting the hypothesis that the endothelium is a key target organ of COVID-19.

Stem cells are nurtured and regulated by a specialized microenvironment known as stem cell niche. While the functions of the niches are well defined, their structure and location remain unclear. We have identified in rat bone marrow, the seat of hematopoietic stem cells, extensively vascularized node-like compartments that fit the requirements for stem cell niche and which we called hemmules. Hemmules are round or oval structures of about one millimeter in diameter that are surrounded by a fine capsule, have afferent and efferent vessels, are filled with the extracellular matrix and mesenchymal, hematopoietic, endothelial stem cells, and contain cells of the megakaryocyte family, which are known for homeostatic quiescence and contribution to the bone marrow environment. We propose that hemmules are the long sought hematopoietic stem cell niches and that they are prototypical of stem cell niches in other organs.

Fasudil, a potent Rho kinase (ROCK) inhibitor, can ameliorate LPS-induced acute lung injury (ALI) in mice, but the mechanism remains obscure. In this study, a mice model of ALI was established by intra-tracheal instillation of LPS. Histological changes, cytokine levels, lung permeability, and endothelial apoptosis were determined to evaluate the effects of fasudil on lung injury. The cellular and molecular biological mechanisms were explored by culturing human pulmonary microvascular endothelial cells (PMECs). The results showed that fasudil reduced LPS-induced lung inflammation, pulmonary hyperpermeability, and endothelial apoptosis in mice. In cultured human PMECs, fasudil inhibited LPS-induced caspse-3 cleavage and cell apoptosis. It also decreased LPS-induced hyperpermeability of human PMECs monolayer by reversing the down-regulation of intercellular junctions. Moreover, fasudil inhibited LPS-induced overexpression of chemokines and intercellular adhesion molecule (ICAM)-1 in human PMECs, which in turn suppressed neutrophil chemotaxis and neutrophil-endothelial adhesion. Further molecular researches showed fasudil inhibited LPS-induced activation of ROCK, NF-κB, and p38 in human PMECs. Our findings demonstrated that fasudil alleviated LPS-induced ALI by protecting endothelial function via inhibiting endothelial apoptosis, maintaining endothelial barrier integrity, and reducing endothelial inflammation. These effects of fasudil could be attributed to the inhibition of ROCK and its downstream NF-κB and p38 signaling pathways.

Background: Endotheliopathy is common pathologic findings in patients with acute and long COVID-19. It may be associated with disease severity and predispose to long-term complications. Plasma levels of a proteoglycan syndecan-1 are found to be significantly elevated in patients with COVID-19, but its roles in assessing the disease severity and predicting long-term outcome are not fully understood. Methods: 124 consecutive hospitalized patients with SARS-CoV2 infection were prospectively enrolled and blood samples were collected on admission (T1), 3-4 days following treatment (T2), and 1-2 days prior to discharge or death (T3). Plasma levels of syndecan-1 were determined using an immunosorbent assay; various statistical analyses were performed to determine the association between plasma syndecan-1 levels and disease severity or the 60-day mortality rate. Results: Compared with those in the healthy controls, plasma levels of syndecan-1 in patients with critical COVID-19 were significantly higher (p<0.0001). However, there was no statistically significant difference among patients with different disease severity (p>0.05), resulting from large individual variability. Longitudinal analysis demonstrated that while the levels fluctuated during hospitalization in all patients, plasma syndecan-1 levels were persistently elevated from baseline in critical COVID19 patients. Cox proportional hazard regression analyses revealed that elevated plasma levels of syndecan-1 (>260 ng/mL at T1, >1018 ng/mL at T2, and >461 ng/mL at T3) were significantly associated with the 60-day mortality rate. Conclusions: Endotheliopathy, marked by glycocalyx degradation and elevated plasma syndecan-1, occurs in nearly all hospitalized patients with SARS-CoV2 infection; the elevated plasma syndecan-1 is associated with increased mortality in COVID-19 patients.

Rheumatoid arthritis (RA) is a chronic systemic inflammatory autoimmune disease that affects about 1% of the global population, with a female-male ratio of 3:1. To date, genetic predisposition, the involvement of a deficient immune system and lifestyle are known to be the major responsible for the onset of the disease. RA preferably affects the joints, with consequent joint swelling and deformities followed by ankylosis. Patients suffering from rheumatoid arthritis can also develop extra-articular manifestations, which mainly affect the cardiovascular system, the nervous system, the skin, the eye, the respiratory system, the kidney and the gastrointestinal system. It has been shown that about 20% of RA patients can develop neuropathies, multiple mononeuritis, distal sensory neuropathies and sense motor neuropathies. Neurological involvement occurs as a consequence of vasculitis of the nerve vessels leading to vascular ischaemia, axonal degeneration and neuronal demyelination. In RA, the risk of developing cardiovascular disease is very high and depends, most probably, on vascular damage resulting from endothelial dysfunction. Hence, it is reasonable to assume that the integrity of the endothelium is also involved in the neurological disorders resulting from RA. This review aims to highlight the main characteristics of the extra-articular manifestations at the nervous level resulting from rheumatoid arthritis. To this end, the literature main results on these pathological manifestations have been collected with particular focus on the involvement of endothelial dysfunction. In fact, the endothelium could be considered a valuable target for minimizing the incidence of extra-articular neurological manifestations in RA.

Vascular endothelial growth factor (VEGF) is a important biomarker with significant clinical importance. It plays a key role in angiogenesis, would healing, tumor growth, lung development, and in retinal diseases. Hence, detecting and quantifying VEGF is crucial in clinical diagnosis and prognosis of various diseases. In this work, a simple but highly cost-effective platform is developed for VEGF protein detection by using commercially available interdigitated sensors that are modified through surface chemistry tagged with DNA aptamer grafting. The dielectric characteristics between the fingers of sensor is modulated by the negatively charged aptamer-VEGF capture and the impedance is estimated using impedance analyzer. Impedance spectra tests was compared between pristine unmodified, functionalized monolayer surfaces and aptamer-grafted surfaces in order to evaluate the efficacy of VEGF detection. In our results, the sensitivity experiments as conducted had shown the ability of the interdigitated sensor to detect VEGF at a low concentration of 5 pM. The specificity of the functionalized sensor in detecting VEGF is further studied by comparing the impedance to platelet-derived growth factor (PDGF), and the results confirm the specificity of the sensor. Finally, an alternative illustration of impedance spectra is also proposed to improve the data visualization, and such presentation may be potential for intelligent VEGF detection.

Three-dimensional matrices are a new strategy used to tackle type I diabetes; a chronic metabolic disease characterized by the destruction of beta pancreatic cells. Type I collagen is an abundant extracellular matrix (ECM), component that has been used to support cell growth. However, pure collagen possesses some difficulties including low stiffness and strength, and high susceptibility to cell-mediated contraction. Therefore, we developed a collagen hydrogel with a poly(ethylene glycol) diacrylate (PEGDA) interpenetrating network (IPN), functionalized with vascular endothelial growth factor (VEGF) to mimic the pancreatic environment for the sustenance of beta-pancreatic cells. We analyzed the physicochemical characteristic of the hydrogels and found that they were successfully synthesized. The mechanical behavior of the hydrogels improved with the addition of VEGF, and the swelling degree and the degradation were stable over time. In addition, it was found that 5 ng/mL VEGF-functionalized collagen/PEGDA IPN hydrogels sustained and enhanced viability, proliferation, respiratory capacity and functionality of beta pancreatic cells. Hence, this is a potential candidate for future preclinical evaluation, which may be favorable for diabetes treatment.

Prothrombotic thrombocytopathy mimicking heparin-induced thrombocytopenia has been observed in patients with severe COVID-19 and after immunisation with the Vaxzevria vaccine. Herein, we discuss the pathogenesis of this disorder focusing on the possible involvement of anti-platelet factor 4 (PF4) autoantibodies.

In atherosclerosis patients, vascular endothelial dysfunction is commonly observed with damage of vascular endothelial glycocalyx, an extracellular matrix-bound to and encapsulating the endothelial cell lining the blood vessel wall. Unfavorable lifestyle; smoking and physical inactivity, also induces glycocalyx degradation. Moreover, the vascular endothelial glycocalyx is damaged by various unfavorable disease conditions like as dehydration, acute infectious disease, trauma, sepsis, ARDS, Kawasaki disease, preeclampsia, gestational diabetes mellitus, hypertension, diabetes, chronic kidney disease, atherosclerosis, stroke, dementia, microvascular angina, acute coronary syndrome, and heart failure. The vascular endothelial glycocalyx has been shown to be important not only as a physical cytoprotective barrier for vascular endothelial cells but also as a mechanism that regulates intracellular cell signaling. Therefore, vascular endothelial glycocalyx has great potential to explore new strategies for assessing the benefit conditions of our healthy vasculature.

Beyond plasma glucose-lowering in patients with type 2 diabetes, sodium- glucose cotransporter 2 inhibitors (SGLT2i) significantly reduced the hospitalization for heart failure (HF) and retarded the progression of chronic kidney disease (CKD). Endothelial dysfunction is not only involved in the development and progression of cardiovascular disease (CVD), and is also associated with the progression of CKD. In patients with type 2 diabetes, hyperglycemia, insulin resistance, hyperinsulinemia and dyslipidemia induce the development of endothelial dysfunction. SGLT2i have shown an improvement in endothelial dysfunction, as assessed by flow-mediated vasodila-tion, in individuals at high risk for CVD. Along with an improvement of endothelial dysfunction, SGLT2i showed improvements in oxidative stress, inflammation, mitochondrial dysfunction, glucotoxicity such as advanced glycation end products signaling and nitric oxide bioavailability. The improvements in endothelial dysfunc-tion and such endothelium-derived factors may play an important role in preventing the development of coronary artery disease, coronary microvascular dysfunction and diabetic cardiomyopathy which cause HF and in retarding CKD. The suppression of the development of HF and the progression of CKD achieved by SGLT2i might have been largely induced by the improvement of vascular endothelial function by SGLT2i.

Since the first description of COVID-19 infection, among clinical manifestations of the disease including fever, dispnea, cough, fatigue, it was observed a high incidence of thromboembolic events potentially evolving towars ARDS and COVID-associated-coagulopathy (CAC).The hypercoagulation state is based on an interaction between thrombosis and inflammation. The so-called CAC represents a key aspect in the genesis of organ damage from SARS-CoV-2. The prothrombotic status in COVID-19 disease can be explained by the increase of coagulation levels of D-dimer, lymphocytes, fibrinogen, IL-6 and prothrombin time. Several mechanisms have been hypothesized to explain this hypercoagulable process such as inflammatory cytokine storm, platelet activation, endothelial dysfunction and stasis for a long time. The purpose of this narrative review is to provide an overview of the current knowledge on the pathogenic mechanisms of coagulopathy that may characterize COVID-19 infection and inform on new areas of research. New vascular therapeutic strategies are also reviewed.

One of the hallmarks of the SARS-CoV-2 infection has been the inflammatory process that played a role in its pathogenesis, resulting in mortality within susceptible individuals. This uncontrolled inflammatory process leads to severe systemic symptoms via multiple pathways, however, the role of endothelial dysfunction and thrombosis have not been truly explored. This review aims to highlight the pathogenic mechanisms of these inflammatory triggers leading to thrombogenic complications. There are direct and indirect pathogenic pathways of the infection that are examined in detail. We also describe the case of carotid artery thrombosis in a patient following the SARS-CoV-2 infection, while reviewing the literature on the role of ACE2, the endothelium, and the different mechanisms by which SARS-CoV-2 may manifest both acutely and chronically. We also highlight differences from the other coronaviruses that have made this infection pandemic with similarities to the influenza virus.

Myocardial infarction (MI) remains the leading cause of death in the western world. Although medical advancements have been made in interventional revascularization technologies, a large percentage of patients are not candidates for them due to co-morbidities or lack of local resources. Thus, there remains a need for the development of novel non-invasive strategies to treat MI. Approaches to accelerate revascularization within ischemic tissues through angiogenesis by providing Vascular Endothelial Growth Factor (VEGF) in protein or gene form has been shown to be effective in animal models but not in humans likely due to its short half-life and systemic toxicity. We previously showed that a small peptide (PR1P) we developed stabilizes VEGF in its active dimer state, increases VEGF binding to its receptors and potentiates VEGF activity. Here we show that systemic PR1P treatment targeted, stabilized and upregulated endogenous VEGF within ischemic myocardium following left coronary artery surgery in mice and rats. Targeted VEGF upregulation led to augmentation of heart function at two weeks following surgery. We conclude that PR1P is a potential candidate therapeutic for MI.

Angiogenesis is a complex process that involves interactions between endothelial cells and various other cell types as well as the tissue microenvironment. Several previous studies have demonstrated that mast cells accumulate at angiogenic sites. In spite of the evidence suggesting a relationship between mast cells and angiogenesis, the association of mast cells and endothelial cells remains poorly understood. The present study aims to investigate the relationship between mast cells and endothelial cells during in vitro angiogenesis. When endothelial cells were co-cultured with mast cells, angiogenesis was stimulated. Furthermore, there was direct intercellular communication via gap junctions between the two cell types. In addition, the presence of mast cells stimulated endothelial cells to release angiogenic factors. Moreover, conditioned medium from the co-cultures also stimulated in vitro angiogenesis. The results from this investigation demonstrate that mast cells have both direct and indirect proangiogenic effects and provide new insights into the role of mast cells in angiogenesis.

Abstract Metabolic syndrome (MetS) is considered a metabolic disorder that has been steadily increasing globally and seems to parallel the increasing prevalence of obesity. It consists of a cluster of risk factors, which traditionally includes obesity and hyperlipidemia, hyperinsulinemia, hypertension, and hyperglycemia. These four core risk factors are associated with insulin resistance (IR) and importantly, the MetS is known to increase the risk for developing cerebrocardiovascular disease and type 2 diabetes mellitus. The MetS had its early origins in IR and syndrome X. It has undergone numerous name changes with additional risk factors and variables being added over the years; however, it still remains the MetS worldwide for the past three decades. This overview continues to add novel insights to the MetS and suggests that leptin resistance with hyperleptinemia, aberrant mitochondrial stress and reactive oxygen species (ROS), impaired folate-mediated one-carbon metabolism with hyperhomocysteinemia, vascular stiffening, microalbuminuria, and visceral adipose tissues extracellular vesicle exosomes be added to the list of associated variables. Notably, the role of a dysfunctional and activated endothelium and deficient nitric oxide bioavailability along with a dysfunctional and attenuated endothelial glycocalyx, vascular inflammation, systemic metainflammation, and the important role ROS and reactive species interactome are discussed. With new insights and knowledge regarding the MetS, comes the possibility of new findings through further research.

Endothelial integrity plays a major role in homeostasis and is responsive to the numerous endogenous factors released. While its functional role in vascular tone is well described, its role in the pathophysiology of cardiovascular disease is of interest as a potential therapeutic target. We performed a systematic review to provide an overview of new therapeutic and diagnostic targets for the treatment of coronary artery disease related to endothelial dysfunction. Databases of PubMed, Ovid’s version of MEDLINE, and EMBASE were interrogated with appropriate search terms. 28 studies met inclusion criteria and were included in the final systematic review. We identified inflammation, pulmonary hypertension, diabetes mellitus and Fabry disease as pathophysiological mechanisms and explored the therapeutic options related to these conditions including medications such as Canakinumab. Endothelial dysfunction has a key role in several different pathophysiological processes which can be targeted for therapeutic options. Ongoing research should be targeted at making the transition to clinical practice. Further research is also needed on understanding the amelioration of endothelial dysfunction with the use of cardiovascular medications.

Increased soluble endoglin (sENG) were observed in human brain arteriovenous malformations (bAVMs), and overexpression of sENG with vascular endothelial growth factor (VEGF)-A induced dysplastic vessel formation in mouse brain. However, the underlying mechanism of sENG-induced vascular malformations is not clear. While evidence suggests the role of sENG as a pro-inflammatory modulator, increased microglial accumulation and inflammations were observed in bAVMs. Therefore, we hypothesized that microglia mediate sENG-induced inflammation and endothelial cell (EC) dysfunction in bAVMs. In this study, we confirmed that sENG with VEGF-A overexpression induced dysplastic vessel formation. Remarkably, there were increased microglial activation around dysplastic vessels with expression of NLRP3, inflammasome marker. We found that sENG increased the gene expression of VEGF-A, pro-inflammatory cytokines/inflammasome mediators (TNF-α, IL-6, NLRP3, ASC, Caspase-1, and IL-1β), and proteolytic enzyme (MMP-9) in BV2 microglia. The conditioned media from sENG-treated BV2 (BV2-sENG-CM) significantly increased angiogenic factors (Notch-1 and TGFβ) and pERK1/2 in ECs while it decreased IL-17RD, an anti-angiogenic mediator. Finally, the BV2-sENG-CM significantly increased EC migration and tube formation. Together, our study demonstrates that sENG provokes microglia to release angiogenic/inflammatory responses which may be involved in EC dysfunction. Our study suggests the contribution of microglia in the pathology of sENG-associated vascular malformations.

Severe COVID-19 is associated with viraemia and multiple organ disease. Similar clinicopathological features have been previously seen in SARS and MERS. Clinically, the severity of SARS, MERS and COVID-19 has been associated with the presence of SARS-CoV, MERS-CoV or SARS-CoV2 viraemia in affected patients. In vitro work has looked at the pattern of viral entry and release from polarised epithelial cells infected by coronaviruses. This work has demonstrated a correlation between the severity of a coronavirus infection and the ability of the virus to reach and infect the basal surface of host cells. It has been postulated that this ability helps the virus invade the bloodstream of the host, resulting in a systemic infection with multiple organ involvement. Here we propose that basal surface release and entry of COVID-19 into and out of cells at epithelial-endothelial interface plays a key pathogenic role in severe COVID-19 disease.

Porous coatings on prosthetic implants encourage implant fixation. Enhanced fixation may be achieved using a magneto-active porous coating that can deform elastically in vivo on application of an external magnetic field, straining in-growing bone. Such coating, made of 444 ferritic stainless steel fibres, was previously characterised in terms of its mechanical and cellular responses. In this work, co-cultures of human osteoblasts and endothelial cells were seeded into a novel fibrin-based hydrogel embedded in a 444 ferritic stainless steel fibre network. Albumin was successfully incorporated into fibrin hydrogels improving the specific permeability and the diffusion of fluorescently-tagged dextrans without affecting their Young’s modulus. The beneficial effect of albumin was demonstrated by upregulation of osteogenic and angiogenic gene expression. Furthermore, mineralisation, extracellular matrix production and formation of vessel-like structures were enhanced in albumin-enriched fibrin hydrogels compared to fibrin hydrogels. Collectively, the results indicate that the albumin-enriched fibrin hydrogel is a promising bio-matrix for bone tissue engineering and orthopaedic applications.

The eyes are the sense organs through we view the world around us, and the cornea is the transparent layer which covers the outer, visible part of the eye. It is known that the gene expression of corneal endothelium depends on age. And the expressed genes of the endothelium of cornea for pediatric samples is different than that of the adult samples. The purpose or objective of this study was to characterize human corneal endothelial cell (HCEnC) gene expression and differential gene expression and to detect the expressed genes mapped to chromosomal loci associated with some corneal endothelial dystrophies. Both upregulated and downregulated genes were analyzed. For this purpose, total RNA was isolated from ex vivo corneal endothelium taken from six pediatric and five adult corneas. The complementary DNA was hybridized to the Affymetrix GeneChip 1.1 ST array. The data analysis was performed using the Enrichr software for both upregulated and downregulated genes. These are described in more detail in the results and discussion section. This study uses bioinformatics tools to identify and analyse gene sets present in the transcriptome of the corneal endothelium, and tries to find out and observe the relation of the aging effect on the corneal endothelium gene expression. The human subjects had participated voluntarily and informed consent was obtained from all before carrying out any testing procedure. Proper guidelines from the hospital ethical committee were also followed and no harmful chemicals were used on the participants. This study simply aims to raise some awareness of the given topic among the local people so that they are better able to take informed choices about their health in the near future, and also so that they seek medical help when necessary and have no inhibitions in doing so.

Sea anemones are a remarkable source of active principles due to a decentralized venom system. Blood vessel formation or angiogenesis is a very promising target against cancer, but the few available anti-angiogenic compounds have a limited efficacy. In this study, a protein fraction was purified from tentacles of Anemonia viridis able to limit endothelial cells proliferation and vessel network formation or angiogenesis at low concentration (14 nM). The sequences in this protein fraction were determined with Edman degradation and Mass Spectrometry In Source Decay and revealed homologies with BDS sea anemones. The presence of a two turn alpha helix observed with Circular Dichroism and a trypsin activity inhibition suggested that the active principle could be a Kunitz-type inhibitor, which may interact with an integrin due to a RGD motif well exposed to the solvent as revealed by Molecular Modeling. This active principle could improve antiangiogenic therapy from existing antiangiogenic compounds binding on the VEGF.

Background: The hypothesis is that a hypoxic-hyperoxic preconditioning (HHP) is associated with a protective effect on myocardial function by reducing endothelial damage and a beneficial effect on postoperative outcome in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). Methods: Patients (n=120) were randomly assigned to an HHP and a control group. A safe inhaled oxygen fraction for the hypoxic preconditioning phase (10-14% oxygen for 10 minutes) was determined by measuring the anaerobic threshold. At hyperoxic phase, 75-80% oxygen fraction was used during 30 minutes. Results: The cumulative frequency of postoperative complications was 14 (23.3%) in the HHP vs 23 (41.1%), p=0.041. The nitrate decreased after surgery by up to 20% in the HHP group and up to 38% in the control group. Endothelin-1 and nitric oxide metabolites were stable in HHP but remained low more than 24 h in control group. The endothelial damage markers appeared to be predictors of postoperative complications. Conclusion: The HHP with individual parameters based on the anaerobic threshold is a safe procedure, it can reduce the frequency of postoperative complications. The endothelial damage markers appeared to be predictors of postoperative complications.

Curcumin is a natural dietary polyphenol which that possesses potent anti-aging and neuroprotective properties through various mechanisms and signaling pathways. This study aimed to investigate the effect of curcumin on factors involved in neurogenesis and angiogenesis in the aged brain. Old female Wistar rats were divided into three equal groups (n=7): control, sham, and curcumin (received curcumin, i.p., 30 mg/kg and 5 days/week for 8 weeks) rats. Curcumin treatment caused a significant increase in the vascular endothelial growth factor (VEGF), Brain-derived neurotrophic factor (BDNF) and anti-apoptotic protein BCl-2 in the brains of aging rats but no significant effect on anti-apoptotic Bax protein. Additionally, curcumin attenuated brain lipid peroxidation and decreased transforming growth factor β1 (TGF-β1). These results suggested that curcumin possesses neuroprotective effects against brain aging, which were mediated by improvment in neurogenesis and angiogenesis. Also, curcumin could alleviate brain aging which may be due to attenuating oxidative stress, inhibiting apoptosis and down-regulating TGF-β1, which in turn enhances VEGF and BDNF. Therefore, curcumin has potential therapeutic value in the treatment of neurological apoptosis, neurogenesis and angiogenesis changes caused by brain aging.

The endothelium plays a key role in blood vessel health. At the interface of the blood, it releases several mediators that regulate local processes and that protect against the development of cardiovascular disease. In this interplay, there is increasing evidence for a role of extracellular nucleotides and endothelial purinergic P2Y receptors (P2Y-R) in vascular protection. Recent advances have revealed that endothelial P2Y1-R and P2Y2-R mediate nitric oxide-dependent vasorelaxation as well as endothelial cell proliferation and migration, which are processes involved in the regeneration of damaged endothelium. However, endothelial P2Y2-R, and possibly P2Y1-R, have also been reported to promote vascular inflammation and atheroma development in mouse models, with endothelial P2Y2-R also being described as promoting vascular remodeling and neointimal hyperplasia. Interestingly, at the interface with lipid metabolism, P2Y12-R has been found to trigger HDL transcytosis through endothelial cells, a process known to be protective against lipid deposition in the vascular wall. Better characterization of the role of purinergic P2Y-R and downstream signaling pathways in determination of the endothelial cell phenotype in healthy and pathological environments has clinical potential for the prevention and treatment of cardiovascular diseases.

Rising child obesity rate creates a need for tools quantifying metabolic changes in obese children and adolescents for purposes of comorbidities early detection or prevention. A candidate for such role seem to be miRNAs – in vivo serving as the suppressing factors of the gene expression. The aim of this study was to review the recent discoveries in this field and to conclude directions of research or application of studied molecules. Repeated browsing of databases, followed by screening for eligibility of results, led to final approval of 9 articles. Filtered studies examined the differences in miRNA (miR) expression levels of obese subjects and children suffering from obesity comorbidities. Studies concerning the endothelial dysfunction (ED) identified miR-630 as a possible treatment option. Search for the alternative markers in diagnosis of non-alcoholic fatty liver disease (NAFLD) suggested value of miR-199a-5p and miR-122. MiR-486, miR-146b and miR-15b may serve as a panel of markers grading the development of type 2 diabetes mellitus (T2DM) in children, although further research raised doubts in that matter. Another panel of miRNA molecules was indicated as useful in early detection of alterations leading to metabolic syndrome (MetS). No valid link between studied miRNAs and atherosclerosis (AS) was found. MiRNAs seem to be promising prognostic markers for the diagnosis of NAFLD, T2DM and MetS in children. Further studies are required to support these findings.

Discovery of inhibitors for endothelial-related transcription factors can contribute to the development of angiogenic therapies that treat diseases ranging from cardiovascular to cancer. The role of transcription factor Vezf1 in vascular development and regulation of angiogenesis has been defined by several earlier studies. Through construction of a computational model for Vezf1, work here has identified a novel small molecule drug capable of inhibiting Vezf1 from binding to its cognate DNA binding site. Using structure-based design and virtual screening of the NCI Diversity Compound Library, 12 shortlisted compounds were tested for their ability to interfere with the binding of Vezf1 to DNA using electrophoretic gel mobility shift assays. We identified one compound, T4, which has an IC50 of 20uM. Using murine endothelial cells, MSS31, we tested the effect of T4 on endothelial cell viability and angiogenesis by using tube formation assay. Our data show that addition of T4 in cell culture medium does not affect cell viability at concentrations lower or equal to its IC 50 but strongly inhibits the network formation by MSS31 in the tube formation assays. Given its potential efficacy, this inhibitor has significant therapeutic potential in several human diseases raging from wound healing to cancer.

As the name implies, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a single-stranded RNA virus and a member of the corona virus family, primarily affecting the upper respiratory system and the lungs. Like many other respiratory viruses, SARS-CoV-2 can spread to other organ systems. Apart from causing diarrhea, another most common but debilitating complication caused by the SARS-CoV-2 is neurological symptoms and cognitive difficulties, which occur in up to two thirds of hospitalized covid patients and ranging from shortness of concentration, overall declined cognitive speed to executive or memory function impairment. Neuro-cognitive dysfunction and “brain fog” are frequently present in COVID-19 cases, which can last several months after the infection, leading to disruption of daily life. Cumulative evidence suggests that SARS-CoV-2 affects vasculature in the extra pulmonary systems directly or indirectly, leading to impairment of endothelial function and even multi-organ damage. The post COVID-19 long-lasting neurocognitive impairments have not been studied fully; and the underlying mechanism remains elusive. In this review, we summarize the current understanding of the effects of COVID-19 on vascular dysfunction and how vascular dysfunction leads to cognitive impairment in patients.

Background and Objectives: Acute lung injury (ALI) is an inflammatory response in the lung caused by bacteria, viruses, trauma and other factors that results in lack of alveolar surfactant and subsequently respiratory distress. Endothelial-to-mesenchymal transition (EndoMT) is closely related to ALI-induced pulmonary fibrosis development and progression. This study examined the effect of milk fat globulin factor 8 (MFGE8) knockdown and overexpression on lipopolysaccharide (LPS)-induced EndoMT. Methods: Total MFGE8 activity in patients with acute respiratory distress syndrome (ARDS) and healthy volunteers was assessed using a colorimetric kit. In vitro, cell morphology was observed by microscopy, and invasion and migration were tested by Transwell and scratch assays. Specific siRNAs were transfected into HLMECs to downregulate MFGE8, and CD31 and α-SMA protein expression was detected by fluorescence microscopy and FCM. MFGE8, BMP, Smad 1, Smad4, Smad5, Snail, CD31 and α-SMA protein and gene expression was assessed by western blotting (WB) and qRT‒PCR. In vivo, the changes in cell morphology and alveolar septum in the lung of mice (C57BL/6, aged 7-8 weeks, male) were observed by H&E staining. In addition, ECM deposition in lung tissue was detected by Masson staining. CD31 and α-SMA protein expression in lung tissue was measured by WB. Results: The serum level of MFGE8 was lower in the ARDS group than in the control group. MFGE8 was identified as a protective factor associated with hospital survival. In vitro, the treatment of human lung microvascular endothelial cells (HLMECs) with LPS for 96 h clearly changed the cells from the typical cobblestone shape of ECs to spindle-like fibroblasts. The scratch and Transwell assay results indicated that endothelial cell migration and invasion were enhanced in the LPS group compared with the control group. Fluorescence microscopy, FCM, WB and PCR showed that LPS greatly inhibited CD31 (endothelial marker) expression and increased α-SMA (mesenchymal marker) expression. These data showed that LPS could induce EndoMT in HLMECs. Notably, siRNA-treated HLMECs yielded the same results. The administration of rhMFGE8 to HLMECs in the LPS or LPS+siRNA group ameliorated the changes in cell morphology and decreased cell migration and invasion. rhMFGE8 attenuated the effect of LPS or LPS+siRNA on EndoMT induction by increasing CD31 and decreasing α-SMA protein and gene expression. Moreover, activation of BMP/Smad1/5-Smad4 signalling in response to LPS and Snail (related to EndoMT transcription factors) expression were increased by MFGE8 knockdown but inhibited by rhMFGE8. In vivo, H&E staining revealed a thickened alveolar septum in the LPS group, and the thickness increased over time; in contrast, rhMFGE8 reversed this effect. ECM deposition occurred early in ALI induced by LPS and increased over time, and the administration of rhMFGE8 reversed this effect. WB showed that LPS inhibited CD31 protein expression and increased α-SMA protein expression in lung tissue. Conclusions: rhMFGE8 exerts a protective effect early in LPS-induced EndoMT through BMP/Smad1/5/Smad4 signalling and could be a therapeutic target in ALI.

Torenia Concolor Lindley var. formosama Yamazaki ethanolic extract (TCEE) is reported to have anti-inflammatory and anti-obesity properties. However, the effects of TCEE and its underlying mechanisms in the activation of endothelial nitric oxide synthase (eNOS) have not yet been investigated. Increasing the endothelium-derived nitric oxide (NO) production has been known to be beneficial against the development of cardiovascular diseases. In this study, we investigated the effect of TCEE on eNOS activation and NO-related endothelial function and inflammation by using in vitro system. In endothelial cells (ECs), TCEE increased NO production in a concentration-dependent a manner without affecting the expression of eNOS. In addition, TCEE increased the phosphorylation of eNOS at serine 635 residue (Ser635) and Ser1179, Akt at Ser473, calmodulin kinase II (CaMKII) at threonine residue 286 (Thr286) and AMP-activated protein kinase (AMPK) at Thr172. Moreover, TCEE-induced NO production, and EC proliferation, migration and tube formation were diminished by pretreatment with LY294002 (an Akt inhibitor), KN62 (a CaMKII inhibitor) and compound C (an AMPK inhibitor). Additionally, TCEE attenuated the tumor necrosis factor-α-induced inflammatory response as evidenced by the expression of adhesion molecules in ECs and monocyte adhesion onto ECs. These inflammatory effects of TCEE were abolished by L-NG-nitroarginine methyl ester (a NOS inhibitor). Collectively, our findings suggest that TCEE confers protection from endothelial dysfunction by activating the Akt/CaMKII/AMPK/eNOS/NO signaling pathway.

Effective biomarkers are essential to the early diagnosis of non-small cell lung cancer (NSCLC). Herein, a retrospective study of 49 newly diagnosed and recurrent NSCLC patients, 31 patients with benign pulmonary disease and 24 healthy volunteers was conducted, to evaluate the diagnostic value of circulating rare cells for NSCLC. The expression of circulating tumor cells (CTCs) and circulating tumor-derived endothelial cells (CTECs) in peripheral blood were measured by subtraction enrichment-immunostaining-fluorescence in situ hybridization (SE-iFISH). The level of CTCs (P＜0.001) and CTECs (P＜0.001) was significantly higher in NSCLC group than that in benign pulmonary disease group. The proportion of small CTCs (P＜0.001) and CTECs (P＜0.0001) significantly increased from benign lung disease individuals to NSCLC patients. The AUC of ROC curves of total CTCs and CTECs were 0.815 (95%CI: 0.722~0.907), 0.739 (95%CI: 0.618~0.860), respectively. The cut-off values for discriminating NSCLC with benign lung disease patients were total CTCs 11.5 units/6ml and total CTECs 10.5 units/6ml, with sensitivity and specificity being 67.3% and 83.9%, 77.6% and 77.4%, respectively. When CTCs and CTECs were combined, predictive value significantly increased to 82.6% as measured by the area under the curve. Small CTCs and triploid CTCs had high positive predictive value (PPV) and positive likelihood ratio (LR+) of the diagnosis of NSCLC in early stage. CTCs and CTECs can not only be used as new biomarkers for the diagnosis of NSCLC, but can also improve diagnostic performance of the early stage NSCLC. Moreover, the combined examination of CTCs and CTECs is be superior to the single.

Cardiovascular disease (CVD) comprises a group of heart and circulatory disorders, which are regarded as a global medical issue with high prevalence and mortality rates. Currently, vascular regenerative surgery represents the most employed therapeutic option to treat ischemic disorders, even though not all the patients are amenable to surgical revascularization. Therefore, more efficient therapeutic approaches are urgently required to promote neovascularization. Therapeutic angiogenesis represents an emerging strategy that aims at reconstructing the damaged vascular network by stimulating local angiogenesis and/or promoting de novo blood vessel formation according to a process known as vasculogenesis. Circulating endothelial colony forming cells (ECFCs), in turn, represent truly endothelial precursors able to aggregate into bidimensional tube networks and to originate patent vessels. Accordingly, ECFCs provide the most rationale and promising cellular candidate for therapeutic purposes. The current review provides a brief outline on the origin and characterization of ECFCs and a summary of the progress in preclinical studies aiming at assessing their efficacy in a variety of ischemic disorders, including AMI, PAD, ischemic brain disease and retinopathy. We also describe how to enhance the vasoreparative potential of ECFCs by boosting specific pro-angiogenic signalling pathways either pharmacologically or through gene manipulation. Taken together, these observations suggest that ECFCs represent a useful strategy to treat ischemic diseases.

The RAINBOW Phase III study established the efficacy of the combination of paclitaxel and ramucirumab, a monoclonal antibody targeting VEGF receptor-2 (VEGF-R2), as second-line therapy. We retrospectively analyzed the data of patients treated with ramucirumab plus paclitaxel at our Institution to evaluate the impact of clinical heterogeneous figures on the efficacy and safety of this combination paclitaxel/ramucirumab in a real- life cohort of patients. After a median follow-up of 10.74 months, the median progression-free survival (PFS) was 5.8 months (95% CI: 3.04 - 5,63). Disease control rate (DCR) was 61% and the median duration of response (DOR) was 5.8 months. Median overall survival (OS) was 8.3 months. A trend toward better outcome was observed in HER2 positive patients. In multivariate analysis, nutritional status (p = 0.0001) and number of metastatic sites (p = 0.0266) resulted significantly related with longer PFS. Our analysis confirmed the efficacy and safety of the combination of ramucirumab with paclitaxel also in the real-life practice and the median PFS is significantly longer than that reported for Western population in previous studies. Subgroup analysis confirms the key-role of nutritional status as prognostic factor and suggests a possible interaction between EGF and angiogenesis pathways that deserves further investigations.

This review describes the positive effects of growth hormone on the cardiovascular system. We analyze why the vascular endothelium is a real internal secretion gland, whose inflammation is the first step for developing atherosclerosis, as well as the mechanisms by which GH acts on the vascular endothelium improving its dysfunction. We also report how GH acts on coronary arterial disease and heart failure, and on peripheral arterial disease inducing the generation of new collateral vessels able to bypass a major artery occlusion. We include some preliminary data from a trial in which GH or placebo is given to elder people suffering from critical limb ischemia, showing the effects of the hormone on plasma markers of inflammation, and stating that the administration of GH in short periods of time is safe and effective even in diabetic patients. We also analyze how Klotho may have strong relationships with GH, inducing, after being released from the damaged vascular endothelium, the pituitary secretion of GH to repair the damaged tissue. Lastly, we show how GH induces wound healing by increasing the blood flow to the ischemic tissue. In summary, we postulate that short-time GH administration is useful for treating cardiovascular diseases.

Ral-interacting protein 76 (RLIP76) is a potential factor with vascular endothelial growth factor (VEGF) in the corpus luteum and tumor angiogenesis. RLIP76, VEGF, and hypoxia-inducible factor-1 (HIF-1) are proteins that activate angiogenic functions in tumor and endothelial cells. RLIP76 is a main factor in tumor growth, and VEGF is a major endothelial cell protein for angiogenesis. Also, RLIP76 regulates a small GTPase (R-Ras, oncogene) in cell survival, spreading, and migration. HIF-1 is important in the corpus luteum, tumor angiogenesis, and tumor growth. VEGF and HIF-1 regulate the angiogenic function of RLIP76, and RLIP76 controls vascular growth in endothelial and tumor cells. RLIP76, R-Ras, VEGF, and HIF-1 may be useful in the research of corpus luteum and cancer therapy and the study of mechanisms of tumor angiogenesis. This review will help to elucidate the roles of RLIP76/R-Ras and VEGF via HIF-1 in corpus luteum and tumor angiogenesis, tumorigenesis, and the specific regulation of RLIP76 in luteal, tumor, and endothelial cells. Thus, we reviewed the angiogenesis of the corpus luteum and tumor in the ovarian and tumor microenvironment.

Endothelial cells form a powerful interface between tissues and immune cells. In fact, one of the underappreciated roles of endothelial cells is to orchestrate immune attention to specific sites. Tumor endothelial cells have a unique ability to dampen the immune responses and thereby maintain an immunosuppressive microenvironment. Recent approaches to trigger immune responses in cancers have focused on activating nucleic acid sensors such as cGAS/STING in combination with immunotherapies. In this review, we present a case for targeting nucleic acid sensing pathways within the tumor vasculature to invigorate tumor immune responses. We introduce two specific nucleic acid sensors, the DNA sensor TREX1 and the RNA sensor RIG-I and discuss their functional roles in the vasculature. Finally, we present perspectives on how these nucleic acid sensors in the tumor endothelium can be targeted in an antiangiogenic and immune activation context. We believe understanding the role of nucleic acid sensing in the tumor vasculature can enhance our ability to design more effective therapies targeting the tumor microenvironment.

The intracellular calcium dynamics in vascular endothelial cells (VECs) in response to wall shear stress (WSS) and/or adenosine triphosphate (ATP) have been commonly regarded as an important factor in regulating VEC function and behavior including proliferation, migration and apoptosis. However, the effects of time-varying ATP signals have been usually neglected in the past investigations in the field of VEC mechanobiology. In order to investigate the combined effects of WSS and dynamic ATP signals on the intracellular calcium dynamic in VECs, a Y-shaped microfluidic device, which can provide the cultured cells on the bottom of its mixing micro-channel with stimuli of WSS signal alone and different combinations of WSS and ATP signals in one single micro-channel, is proposed. Both numerical simulation and experimental studies verify the feasibility of its application. Cellular experimental results also suggest that a combination of WSS and ATP signals rather than a WSS signal alone might play a more significant role in VEC Ca²⁺ signal transduction induced by blood flow.

The adipose-derived mesenchymal stem cells are becoming the tool of choice for many clinical applications and nowadays, nearly 200 clinical trials are running worldwide to prove the efficacy of this cell type for many diseases and pathological conditions. To reach the goal of cell therapies and produce ATMPs as drugs for regenerative medicine, it is necessary to properly standardize the GMP processes and thus collection methods, transportation strategies, extraction protocols and characterization procedures without forgetting that all the tissues of the human body are characterized by a wide inter-individual variability genetically determined and acquired during life. Here we compare 302 samples processed under GMP rules to exclude the influence of the operator and of the anatomical site of collection. Variability in the age of patients, gender and laboratory parameters like total cell number, cell viability, stem cell number and other stromal vascular fraction cell sub-populations have been compared to each other. Results show that, when the laboratory protocol is standardized, the variability in quantifiable cell parameters is widely statistically non-significant, meaning that we can make a further step toward standardized advanced cell therapy products.

Abstract: Viremia in coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is often only discussed in passing and there are very few references detailing its structural mechanisms. In addition to viremia in the classic closed cardiovascular system, the lymphatic system is discussed in relation to a possible “lympho-viremia”. The cells that comprise each of these separate but interacting systems will be examined and include endothelial cells, erythrocytes, leukocytes (monocytes/monocyte-derived macrophages and resident tissue macrophages) (lymphocytes) (neutrophils) and thrombocytes -platelets. The SARS-CoV-2 virus has been identified in multiple extrapulmonary target organs at autopsy in those with severe COVID-19 requiring intensive care. Vulnerable COVID-19 patients may suffer from multiple storms including viral/virion storm, redox storm, cytokine storm and thrombo-embolic storm. Therefore, it is important that the possible mechanisms of viremia be explored in greater detail and how these mechanisms might affect intravascular blood components, extracellular tissue interstitium and organ structural remodeling and function. While the co-morbidity of T2DM does not increase the risk of acquiring COVID-19, it is commonly accepted that T2DM increases the risk for COVID-19 admissions to hospitals, assisted ventilation, morbidity and mortality. Importantly, the co-existence of T2DM and COVID-19 may have synergistic detrimental outcomes.

Extracellular vesicles (EVs) represent a heterogeneous population of small vesicles, consisting of a phospholipidic bilayer surrounding a soluble interior cargo. Almost all cell types release EVs, thus they are naturally present in all body fluids. Among the several potential applications, EVs could be used as drug delivery vehicles in disease treatment, in immune therapy because of their immunomodulatory properties and in regenerative medicine. In addition to general markers, EVs are characterized by the presence of specific biomarkers (proteins, miRNAs) that allow the identification of their cell- or tissue-origin. For these features, they represent a potential powerful diagnostic tool to monitor state and progression of specific diseases. As regards, a large body of studies supports the idea that endothelial derived (EMPs) together with platelet-derived microparticles (PMPs) are deeply involved in the pathogenesis of diseases characterized by micro- and macrovascular damages, including diabetes. Existing literature suggests that the detection of circulating EMPs and PMPs and their specific miRNA profile may represent a very useful non-invasive signature to achieve informations about the onset of peculiar disease manifestations. In this Review, we discuss the possible utility of EVs in the early diagnosis of diabetes-associated microvascular complications, specifically related to kidney.

Excessive intracellular glucose in insulin independent tissues including nerve, nephron, lens and retina invites mishandling of metabolism of glucose resulting in a background of increased oxidative stress, advanced glycation end products (AGE) formation, lipid peroxidation and failure of antioxidant defense systems in type 2 diabetes mellitus (T2DM). All these detrimental biochemical anomalies ultimately attack biological membranes and especially capillary beds of retina and glomerulus of kidney, resulting in break-down of inner blood-retinal i.e. initiation of diabetic retinopathy (DR). If these disarrays are corrected to a large extent, development of DR can be avoided or delayed. In this prospective clinical trial, 185 patients with T2DM who received B-vitamins, vitamin-C, and E along with anti-diabetic medication for five years, demonstrated a slower rate of the development of DR and reduced abnormal biochemical mediators like reactive oxygen species (ROS), malondialdehyde (MDA), AGE, and vascular endothelial growth factor (VEGF) compared to 175 T2DM individuals who were treated with only anti-hyperglycemic drugs.

Stroke remains a major cause of death and disability in the United States and around the world. Solid safety and efficacy profiles of novel stroke therapeutics have been generated in the laboratory, but most failed in clinical trials. Investigations into the pathology and treatment of the disease remain a key research endeavor in advancing scientific understanding and clinical applications. In particular, cell-based regenerative medicine, specifically stem cells transplantation, may hold promise as stroke therapy because grafted cells and their components may recapitulate the growth and function of the neurovascular unit, which arguably represents the alpha and omega of stroke brain pathology and recovery. Recent evidence has implicated mitochondria, organelles with a central role in energy metabolism and stress response, in stroke progression. Recognizing that stem cells offer a source of healthy mitochondria, potentially transferrable into ischemic cells, may provide a new therapeutic tool. To this end, deciphering cellular and molecular processes underlying dysfunctional mitochondria may reveal innovative strategies for stroke therapy. Here, we review recent studies capturing the intimate participation of mitochondrial impairment in stroke pathology, and showcase promising methods of healthy mitochondria transfer into ischemic cells, to critically evaluate the potential of mitochondria-based stem cell therapy for stroke.

Ecklonia cava (E.cava) can alleviate vascular dysfunction in diseases associated with poor circulation. E. cava contains various polyphenols with different functions, but few studies have compared the effects of these polyphenols. Here, we comparatively investigated four major compounds present in an ethanoic extract of E. cava. These four major compounds were isolated and their effects were examined on monocyte-associated vascular inflammation and dysfunctions. Pyrogallol-phloroglucinol-6,6-bieckol (PPB) significantly inhibited monocyte migration in vitro by reducing levels of inflammatory macrophage differentiation and of its related molecular factors. In addition, PPB protected against monocyte-associated endothelial cell death by increasing the phosphorylations of PI3K-AKT and AMPK, decreasing caspase levels, and reducing monocyte-associated vascular smooth muscle cell proliferation and migration by decreasing the phosphorylations of ERK and AKT. The results of this study show that four compounds were effective for reduction of monocyte-associated vascular inflammation and dysfunctions, but PPB might be more useful for the treatment of vascular dysfunction in diseases associated with poor circulation.

Anthocyanins, the naturally occurring pigments responsible for most red to blue colours of flowers, fruits and vegetables, have also attracted interests because of their potential health effects. With the aim of contributing to major insights into their structure-activity relationship (SAR), we have evaluated the radical scavenging and biological activities of selected purified anthocyanin samples (PASs) from various anthocyanin-rich plant materials: two fruits (mahaleb cherry and blackcurrant) and two vegetables (black carrot and ‘Sun Black’ tomato). PASs from the above-mentioned plant material have been evaluated for their antioxidant capacity, using TEAC and ORAC assays. In human endothelial cells, we analysed the biological activity of different PASs by measuring their effects on the expression of endothelial inflammatory markers, including endothelial adhesion molecules VCAM-1 and ICAM-1. We demonstrated that all the different PASs showed biological activity. They exhibited antioxidant capacity of different magnitude, higher for samples containing non-acylated anthocyanins (typical for fruits) compared to samples containing more complex anthocyanins acylated with cinnamic acid derivatives (typical for vegetables), even though this order was slightly reversed when ORAC assay values were expressed on molar basis. Concordantly, PASs containing non-acylated anthocyanins reduced the expression of endothelial inflammatory antigens more than samples with aromatic acylated anthocyanins, suggesting the potential beneficial effect of structurally diverse anthocyanins in cardiovascular protection.

Cornea severe inflammation produces opacity or even perforation, scarring, and angiogenesis, resulting in blindness. The cornea can be used to study the effect of new anti-angiogenic chemopreventive agents. We researched the anti-angiogenic effect of two extracts, Methanol (Met) and Hexane (Hex), from the seed of Cucurbita argyrosperma, in the inflamed corneas. The corneas of Wistar rats were alkali-injured and treated intragastrically for seven successive days. Clinical manifestation as opacity score, corneal neovascularization (CNV) area, re-epithelialization percentage, and histological evaluation were performed. Inflammatory (COX-2, NF-κB, and IL-1β), and angiogenic (VEGF-A, VEGFR1, VEGFR2) markers were assessed by immunohistochemistry. Cox-2, Il-1β, and Vegf-a mRNA levels were also determined. After treatments, we observed slim corneal thickness with lower opacity scores and low cell infiltration compared to untreated rats. Treatment also accelerated wound healing and decreased CNV area. The staining of inflammatory and angiogenic factors was significantly decreased. These effects are related to a down-expression of Cox-2, Il-1β, and Vegf. These results suggest that intake of C. argyrosperma seed can be used to attenuate the angiogenesis secondary to inflammation in corneal chemical damage.

Retinal apoptosis plays a critical role in the progression of diabetic retinopathy (DR), a common diabetic complication. Currently, the tight control of blood glucose levels is the standard approach to prevent or delay the progression of DR. However, prevalence of DR among diabetic patients remains high. Focusing on natural nutrients or herbal medicines that can prevent or delay the onset of diabetic complications, we administered an ethanol extract of the aerial portion of Osteomeles Schwerinae (OSSCE), a Chinese herbal medicine, over a period of 17 weeks to spontaneously diabetic Torii (SDT) rats. OSSCE was found to ameliorate retinal apoptosis through the regulation of advanced glycation end products (AGEs) accumulation, oxidative stress, and mitochondrial function via inhibition of NF-κB activity, in turn through the downregulation of PKCδ, P47phox, and ERK1/2. We further demonstrated in 25 mM glucose-treated human retinal microvascular endothelial cells (HRMECs) that hyperoside (3-O-galactoside-quercetin), quercitrin (3-O-rhamnoside-quercetin), and 2''-O-acetylvitexin (8-C-(2''-O-acetyl-glucoside)-apigenin) were the active components of OSSCE that mediated its pharmacological action. Our results provide evidence that OSSCE is a powerful agent that may directly mediate a delay in development or disease improvement in patients of DR.

Specific proteolytic cleavages turn on, modify, or turn off the activity of vascular endothelial growth factors (VEGFs). Proteolysis is most prominent among the lymph­angiogenic VEGF-C and VEGF-D, which are synthesized as precursors that need to undergo enzymatic removal of their C- and N-terminal propeptides before they can activate their receptors. The activating cleavage of VEGF-C is mediated by at least five different proteases: plasmin, ADAMTS3, prostate-specific antigen, cathepsin D, and thrombin. All of these proteases except for ADAMTS3 can also activate VEGF-D. Processing by different proteases results in distinct forms of the "mature" growth factors, which differ in affinity and receptor activation potential. The “default” VEGF-C-activating enzyme ADAMTS3 does not activate VEGF-D and therefore, VEGF-C and VEGF-D do function in different contexts. VEGF-C itself is also regulated in different contexts by different proteases. During embryonic development, ADAMTS3 activates VEGF-C. In contrast, thrombin and plasmin likely activate VEGF-C/-D during tissue injury-induced lymphangiogenesis, and PSA and cathepsin D perhaps during tumor-associated pathological lymphangio­genesis. Additionally, cathepsin D from saliva might activate latent VEGF-C/-D upon wound licking, thereby accelerating healing. Similar to tyrosine kinase receptors and VEGFs themselves, these activating proteases could be targeted to modulate angiogenesis and lymphangiogenesis in relevant diseases.