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.

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.

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 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.