The retinal pigment epithelium (RPE) is an important monolayer of cells present in the outer retina forming a major part of the blood-retina-barrier (BRB). It performs many essential tasks for the maintenance of retinal integrity and function. With increasing knowledge of the retina, it is getting clearer that both common retinal disorders, like age related macular degeneration, and rare genetic disorders originate in the RPE. This calls for a better understanding of the functions of various proteins within the RPE. In this regard, mice enabling an RPE-specific gene deletion are a powerful tool to study the role of a particular protein within the RPE cells in their native environment, simultaneously negating any potential influences of systemic changes. Moreover, since the RPE cells interact closely with the adjacent photoreceptors, these mice also provide an excellent avenue to study the importance of a particular gene function within the RPE to the retina as a whole. In this review, we outline and compare the features of various Cre mice created for this purpose, allowing researchers a well-informed decision on the choice of Cre mouse to use in relation to their research needs.

Novel genetic and epigenetic factors involved in the development and prognosis of idiopathic pulmonary fibrosis (IPF) have been identified. We previously observed that EPB41L3 increased in the lung fibroblasts of IPF patients. Thus, we investigated the role of EPB41L3 in IPF by comparing EPB41L3 mRNA and protein expression of lung fibroblast between patients with IPF and controls. We also investigated the regulation of the epithelial-mesenchymal transition (EMT) in an epithelial cell line (A549), and the fibroblast-to-myofibroblast transition (FMT) in a fibroblast cell line (MRC5), by overexpressing and silencing EPB41L3. EPB41L3 mRNA and protein levels, as measured by RT-PCR, real-time PCR, and western blot, were significantly higher in fibroblasts derived from 14 IPF patients than in those from 10 controls. The mRNA and protein expression of EPB41L3 was upregulated during transforming growth factor-β-induced EMT and FMT. Overexpression of EPB41L3 in A549 cells using lenti-EPB41L3 transfection suppressed the mRNA and protein expression of N-cadherin and COL1A1. Treatment with EPB41L3 siRNA upregulated mRNA and protein expression of N-cadherin. Overexpression of EPB41L3 in MRC5 cells using lenti-EPB41L3 transfection suppressed mRNA and protein expression of fibronectin and α-SMA. Finally, treatment with EPB41L3 siRNA upregulated mRNA and protein expression of FN1, COL1A1, and VIM. Overall, these data strongly support an inhibitory effect of EPB41L3 on the process of fibrosis and suggest therapeutic potential of EPB41L3 as an anti-fibrotic mediator.

The cornea is an avascular tissue which has attracted much attention by the uniqueness of its anatomical characteristics, it has, in proportion, an enormous size, in relation to the number of vessels, because on average few cells in the organism are away more than 30 microns of a blood vessel. However, the cornea, with a diameter of between 11 and 12 mm, is a unique example. It has been tried to explain the notable absence of blood vessels in the cornea, arguing that corneal tissues are able to take oxygen directly from the air. In this article we are explaining that based on the physicochemical characteristics of molecular oxygen and the cell membrane, cytoplasm, water, and cellular metabolism, it is not possible that epithelial corneal cells directly take oxygen from the air, instead, corneal cells have molecules that can dissociate the water molecules thereby these cells, like any other eukaryotic cells, take the oxygen from the intracell water, like plants.

Fire-related deaths are issues for forensic pathologists particularly in ascertaining if death occurred before or during fire. The authors highlight a unique bronchiolar epithelial cytological clue (nuclear heat-induced elongation) determined by active inhalation of hot gases and fumes, not yet described in the literature at distal small airways level.

Cell monolayers, including endothelial and epithelial cells, play crucial roles in regulating the transport of biomolecules to underlying tissues and structures via intercellular junctions. Moreover, the monolayers form a semipermeable barrier across which leukocyte transmigration is tightly regulated. The inflammatory cytokines can disrupt the epithelial and endothelial permeability, thus the reduced barrier integrity is a hallmark of epithelial and endothelial dysfunction related with numerous pathological conditions, including cancer-related inflammation. Therefore, the assessment of barrier function is critical in in vitro models of barrier-forming tissues. This review summarizes the commercially available in vitro systems used to measure the permeability of cellular monolayers. The presented techniques are separated in two large groups: macromolecular tracer flux assays, and electrical impedance measurement-based permeability assays. The presented techniques are briefly described and compared.

To characterize the mechanisms by which the highly-conserved exocyst trafficking complex regulates eye physiology in zebrafish and mice, we focused on exoc5 (aka sec10), a central exocyst component. We analyzed both exoc5 zebrafish mutants and retinal pigmented epithelium (RPE)-specific Exoc5 knockout mice. Exoc5 is present in both the non-pigmented epithelium of the ciliary body and in the RPE. In this study we set out to establish an animal model to study the mechanisms underlying the ocular phenotype and to establish if loss of visual function is induced by postnatal RPE Exoc5-deficiency. Exoc5-/- zebrafish showed smaller eyes, with decreased number of melanocytes in the RPE and shorter photoreceptor outer segments. At 3.5 days post fertilization, loss of rod and cone opsins were observed in zebrafish Tg:exoc5 mutants. Mice with postnatal RPE-specific loss of Exoc5 showed retinal thinning associated with compromised visual function, and loss of visual photoreceptor pigments. This retinal phenotype in Exoc5-/- mice was present at 20-weeks, and the phenotype was more severe at 27-weeks, indicating progressive disease phenotype. We previously showed that the exocyst is necessary for photoreceptor ciliogenesis and retinal development. Here, we report that exoc5 mutant zebrafish and mice with RPE-specific genetic ablation of Exoc5 develop abnormal RPE pigmentation, resulting in retinal cell dystrophy and loss of visual pigments associated with compromised vision. As RPE cells are “downstream” of photoreceptor cells in the visual process, these data suggest exocyst-mediated retrograde communication and dependence between the RPE and photoreceptors.

Background: Interleukin (IL)-33 is a member of interleukin (IL)-1 family of cytokines which has been linked to the development of inflammatory conditions and cancer in the gastrointestinal tract. This study is designed to investigate whether IL-33 has direct effect on human gastric epithelial cells (GES-1) and on human gastric adenocarcinoma cell line (AGS) and gastric carcinoma cell line (NCI-N87), assessing its role in regulation of cell proliferation and cell cycle, apoptosis and necrosis. Cell cycle regulation was also determined in ex vivo gastric cancer samples obtained during endoscopy and surgical procedures. Methods: cell lines and tissue samples underwent stimulation with rhIL-33. Proliferation was assessed by XTT and CFSE assay, we also evaluated apoptosis by Caspase 3/8 Activity assay and Annexin V assays. Cell cycle were analyzed by means of Propidium Iodine assay and gene expression regulation was assessed by RT-PCR Profiling. Results: we found that IL-33 has an antiproliferative and proapoptotic effect on cancer cell line, while it can stimulate proliferation and reduce apoptosis in normal epithelial cell line. These effects are also confirmed by the analysis of cell cycle gene expression which showed a reduced expression of proproliferative genes in cancer cells, in particular genes involved in G0/G1 and G2/M checkpoint. These results are confirmed by the gene expression analysis on surgical and bioptic specimens. Conclusions: the aforementioned results indicate that IL-33 may be involved in cell proliferation in an environment- and cell type-dependent fashion.

Calcium-activated chloride secretion in epithelial tissues described for many years. However, the molecular identity of the channel responsible for the Ca2+-activated Cl− secretion in epithelial tissues has remained a mystery. More recently, TMEM16A has been identified as a new putative Ca2 -activated Cl- channel (CaCC),. The primary goal of this article will be to review the characterization of TMEM16A, as it relates to the physical structure of the channel, as well as, important residues that confer voltage and Ca2+-sensitivity of the channel. This review will also discuss the role of TMEM16A in epithelial physiology and potential associated-pathophysiology. This will include discussion of developed knockout models that have provided much needed insight on the functional localization of TMEM16A in several epithelial tissues. Finally, this review will examine the implications of the identification of TMEM16A as it pertains to potential novel therapies in several pathologies.

The corneal epithelium (CE) is spread between two domains, the outer vascularized limbus and the avascular cornea proper. Epithelial cells undergo constant migration from the limbus to the vision-critical central cornea. Coordinated with this migration the cells undergo differentiation changes where a pool of unique stem/precursor cells at the limbus yields the mature cells that reach the corneal center. Differentiation is heralded by the expression of the corneal-specific Krt12. Processing data acquired by scRNA-Seq we found that the increase of Krt12 expression occurs in four distinct steps within the limbus plus a single continuous increase in the cornea. Differential gene analysis demonstrated that these domains reflect discreet stages of CE differentiation and yielded extensive information of the genes undergoing down or up regulation in the sequential transition from less to more differentiate conditions. The approach allowed the identification of multiple gene cohorts, including a) the genes that have maximal expression in the most primitive, Krt12-negative cell cohort, which is likely to include the stem/precursor cells; b) the sets of genes that undergo continuous increase or decrease along the whole differentiation path, and c) and the genes showing maximal positive or negative correlation with the changes in Krt12.

Age-related macular degeneration (AMD) is a leading cause of irreversible blindness world-wide. We recently reported that polyethylene glycol (PEG) can activate the alternative pathway of the complement system and induce choroidal neovascularization (CNV) in mice. Currently, no other investigator has demonstrated CNV after PEG injection in the mouse eye. The aim of this article is twofold: we review the histologic changes in mouse retina and retinal pigmented epithelium (RPE) after treatment with PEG, and we summarize a model of wet and dry AMD pathogenesis in mice through subretinal PEG treatment of RPE cells and retinal layers. We injected (subretinal) male C57BL/6 mice with 2 μL of solution containing 0.5 mg and 1.0 mg of PEG or PBS in control groups. Eyes were harvested at day 1, 3 and 5 after injection and processed for analysis. Sections were immunohistochemically stained for complement component C3, mem-brane attack complex (MAC), and cytokeratin 18. Light and laser confocal microscopy was used for image capturing. PEG increased deposition of C3 and MAC on RPE cells and on all retinal layers after 1.0 mg injection. PEG induced loss of cellular contacts between RPE cells and migration of RPE cells in the subretinal space at day 1 after PEG injection. After 0.5 mg PEG injection, increased size of RPE cells was detected at day 3 and 5. Apoptotic bodies were observed in outer nuclear layer at day 3 and 5 after 0.5 mg PEG treatment. RPE cells with dark cytoplasm and condensed chromatin were observed. Higher doses of PEG induce CNV, encouraged RPE cell proliferation and death, and damage photoreceptors in mice. This simple and fast model may be useful to explore the pathogenesis of both dry and wet AMD.

Respiratory tract epithelium infection plays a primary role in Nipah virus (NiV) pathogenesis and transmission. Knowledge about infection dynamics and host responses to NiV infection in respir-atory tract epithelia is scarce. Studies in non-differentiated primary respiratory tract cells or cell lines indicate insufficient interferon (IFN) responses. However, studies are lacking to determin-ing complex host response patterns in differentiated respiratory tract epithelia to understand NiV replication and spread in swine. Here we characterized infection and spread of NiV in differenti-ated primary porcine bronchial epithelial cells (PBEC) cultivated at the air-liquid-interface (ALI). After the initial infection of only a few apical cells, lateral spread for 12 days with epithelium disruption was observed without releasing substantial amounts of infectious virus from the api-cal or basal sides. Deep time course proteomics revealed pronounced upregulation of genes re-lated to type I/II- IFN, immunoproteasomal subunits, TAP-mediated peptide transport and MHC I antigen presentation. Spliceosomal factors were downregulated. We propose a model in which NiV replication in PBEC is slowed by a potent and broad type I/II-IFN host response with con-version from 26S proteasomes to immunoproteasomal antigen processing and improved MHC I presentation for adaptive immunity priming. NiV induced cytopathic effects could reflect the focal release of cell-associated NiV, which may contribute to efficient airborne viral spread between pigs.

The retinal pigment epithelium (RPE) is a monolayer of epithelial cells lying between the neural retina and the choroid and is essential for photoreceptor function and viability. Quail Coturnix japonica is a convenient experimental animal model for the study of age and pathological retina processes to an accelerated time regime. The three main types of pigment granules present in the RPE are melanin-containing melanosomes, lipofuscin-containing lipofuscin granules, and mixed melanolipofuscin granules containing both melanin and lipofuscin. It’s known that with aging and pathology in RPE cells the content of melanosomes decreases but lipofuscin and melanolipofuscin granules accumulate. We examined melanolipofuscin granules in macular areas of the quail retina by transmission electron microscopy in young, middle-aged, and old birds, and in middle-aged birds irradiated with blue LED light (450 nm, 4 J/cm2). It has been shown that during photooxidative stress caused by the action of blue light on the quail eye, active fusion of melanosomes and lipofuscin granules occurs with formation of various types, including giant, mixed melanolipofuscin-like granules. Irradiation result in almost twofold decrease in the number of lipofuscin granules and synchronous increase in the number of melanolipofuscin-like granules. Increased accumulation of melanolipofuscin-like granules was also observed in non-irradiated old birds. It is assumed that the decrease in the number of melanosomes in the RPE during aging and photo-oxidative stress is associated with their fusion with lipofuscin granules and subsequent degradation of melanin by reactive oxygen species formed in melanolipofuscin-like granules. The disappearance of melanin deprives the RPE cells of light-filtering and antioxidant protection, and significantly increases the risk of their oxidative stress.

The retinal pigment epithelium (RPE), which ensures the normal functioning of the neural retina, is a pigmented single-cell layer that separates the retina from the Bruch's membrane and the choroid. There are three main types of pigment granules in the RPE cells of the human eye: lipofuscin granules (LG) containing the fluorescent “age pigment” lipofuscin, melanoprotein granules (melanosomes, melanolysosomes) containing the screening pigment melanin and complex melanolipofuscin granules (MLG) containing simultaneously both types of pigments - melanin and lipofuscin. This review examines the functional role of pigment granules in the aging process and in the development of oxidative stress and associated pathologies in RPE cells. The focus is on the process of light-induced oxidative degradation of pigment granules caused by reactive oxygen species. The reasons leading to increased oxidative stress in RPE cells as a result of oxidative degradation of pigment granules are considered. A mechanism has been proposed to explain the phenomenon of age-related decline in melanin content in RPE cells. The essence of the mechanism is that when the lipofuscin part of the melanolipofuscin granule is exposed to light, reactive oxygen species are formed, which destroy its melanin part. As more melanolipofuscin granules are formed with age and the development of degenerative diseases, the melanin in pigmented epithelial cells ultimately disappears.

It is known that during the process of aging there is a significant decrease in the number of melanosomes in the retinal pigment epithelium (RPE) cells of the human eye. We have previously shown that the interaction of melanin melanosomes with superoxide radicals results in its oxidative degradation with the formation of water-soluble fluorescent products. In the present study, we show using fluorescence analysis, HPLC, and mass spectrometry, that visible light irradiation of melanolipofuscin granules isolated from RPE cells of the human eye results in the formation of water-soluble fluorescent products of oxidative degradation of melanin, in contrast to lipofuscin granules and melanosomes irradiation. The formation of these products occurs as a result of oxidative degradation of melanin by superoxide radicals, which are generated by the lipofuscin part of the melanolipofuscin granule. We identified these products both in the composition of melanolipofuscin granules irradiated with visible light, and in composition of non-irradiated but oxidized by superoxide radicals, melanosomes. In melanolipofuscin granules irradiated with visible light, ions that could be associated to melanin oxidative degradation products were identified by applying principal component analysis of time-of-flight secondary ion mass spectrometry (ToF-SIMS) data. Degradation of the intact melanosomes by visible light is also possible; however, this requires significantly higher irradiation intensities than for melanolipofuscin granules. It is concluded that the decrease in the concentration of melanin in RPE cells of the human eye with age is due to its oxidative degradation by reactive oxygen species generated by lipofuscin as part of melanolipofuscin granules under the action of light.

Retinal pigment epithelium (RPE) replacement therapy is evolving as a feasible approach to treat age-related macular degeneration (AMD). In majority of the preclinical studies, RPE cells are transplanted as cell suspension into immunosuppressed animal eyes and transplant effects were monitored only short-term. We investigated long-term effects of human iPSC derived RPE transplants in immunodeficient Royal College of Surgeons (RCS) rat model, in which RPE dysfunction lead to photoreceptor degeneration. iPSC-RPE cultured as polarized monolayer on nanoengineered ultrathin parylene C scaffold was transplanted into the subretinal space of 28-day old immunodeficient RCS rat pups and evaluated after 1, 4 and 11 months. Assessment at early time points showed good iPSC-RPE survival. The transplants remained as a monolayer, expressed RPE specific markers, performed phagocytic function and contributed to vision preservation. At 11-month post-implantation, RPE survival was observed only in 50% of the eyes that were concomitant with vision preservation. Loss of RPE monolayer characteristics at the 11month time point was associated with peri-membrane fibrosis, immune reaction through activation of macrophages (CD 68 expression) and transition of cell fate (expression of mesenchymal markers). The overall study outcome supports the therapeutic potential of RPE grafts despite the loss of some transplant benefits during long-term observations.

We previously showed that, based on the frequency and distribution of specific cell types, rainbow trout (RT) intestinal mucosa is divided in two regions that form a complex nonlinear 3D pattern and have a different renewal rate. This work had two aims. First, to investigate whether the unusual distribution of cell populations reflects a similar distribution of functional activities. To this end, we determined the protein expression pattern of three well defined enterocytes functional markers: Peptide Transporter 1 (PepT1), Sodium-Glucose/Galactose Transporter 1 (SGLT-1) and fatty acid-binding protein 2 (Fabp2). Second, to characterize the structure of RT intestinal stem cells (ISC) niche and to determine whether the different proliferative rates correlate with a different organization and/or extension of the stem cells population. We studied the expression and localization of well-characterized mammal ISC markers: LGR5, HOPX, SOX9, NOTCH1, DLL1 and WNT3A. Our results indicate that morphological similarity is associated with similar function only between the first portion of the mid-intestine and the apical part of the complex folds in the second portion. Mammal ISC markers are all expressed in RT but their localization is completely different suggesting also substantial functional differences. Finally, higher renewal rates are supported by a more abundant ISC population.

Shiga toxin-producing Escherichia coli (STEC) are notorious foodborne pathogens capable of causing severe diarrhea and other life-threatening complications in humans. Cattle remain a major reservoir and asymptomatic carriers of STEC. In reservoir animals, the rectoanal junction (RAJ) serves as the primary colonization site of STEC playing a critical role in its transmission to humans through contaminated food sources. However, the molecular mechanisms behind the adaptation of STEC in the RAJ of the asymptomatic reservoir host and its subsequent infection of human colonic epithelial cells in an event of a foodborne transmission to cause diarrhea remain largely unexplored. This study aimed to unravel the intricate dynamics of STEC O157:H7 serotype in these two distinct host environments: bovine RAJ cells and human colonic epithelial cells, during initial colonization. In this context, comparative transcriptomics analysis was employed to investigate the differential gene expression profiles of STEC O157:H7 during its interaction with these cell types. The bacterial cells were cultured under controlled conditions to simulate the microenvironments of both bovine RAJ and human colonic epithelial cells. Using high-throughput RNA sequencing, we identified key bacterial genes and regulatory pathways that were significantly modulated in response to each specific host environment. Our findings reveal distinct expression patterns of bacterial genes involved in virulence, including adherence, metal iron homeostasis and stress response in STEC O157:H7 grown in bovine RAJ cells as op-posed to human colonic epithelial cells six hours post-infection. Additionally, the comparative analysis highlights the potential role of certain genes in host adaptation and tissue-specific pathogenicity. Furthermore, this study sheds light on the potential factors contributing to the survival and persistence of STEC O157:H7 in the bovine reservoir, and its ability to colonize in-testinal epithelium and cause disease in humans.

Dysfunction of the retinal pigment epithelium (RPE) is associated with several diseases characterized by retinal degeneration, such as diabetic retinopathy (DR). However, it has recently been proposed that outer retinal neurons also participate in the damage triggering. Therefore, we have evaluated possible crosstalk between RPE and photoreceptors in priming and maintaining oxi-dative damage of the RPE. For this purpose, we used ARPE-19 cells as a model of human RPE, grown in normal (NG, 5.6 mM) or high glucose (HG, 25 mM), and unoxidized (UOx) or oxidized (Ox) mammalian retinal rod outer segments (OS). ARPE-19 cells were efficient at phagocytizing rod OS in both NG and HG settings. However, in HG, ARPE-19 cells treated with Ox-rod OS accumulated MDA and lipofuscins and displayed altered LC3, GRP78, and Caspase 8 expression, compared to untreated and UOx-rod OS-treated cells. Data suggest that early oxidative damage may originate from the photoreceptors and subsequently extend to the RPE, providing a new perspective to the idea that retinal degeneration depends solely on a redox alteration of the RPE.

The oral cavity is the gateway for microorganisms into your body where they disseminate not only to the directly connected respiratory and digestive tracts, but also to the many remote organs. Oral microbiota, traveling to the end of the intestine and circulating our body through blood vessels, not only affect a gut microbiome profile, but also many systemic diseases. By gathering information accumulated from the era of focal infection theory to the age of revolution in microbiome research, we propose a pivotal role of “leaky gum”, as an analogy of “leaky gut”, to underscore the importance of the oral cavity in systemic health. The oral cavity has unique structures, the gingival sulcus (GS) and the junctional epithelium (JE) below the GS, which are rarely found anywhere else in our body. The JE is attached to the tooth enamel and cementum by hemidesmosome (HD), which is structurally weaker than desmosome and is thus vulnerable to microbial infiltration. In the GS, microbial biofilms can build up for life, unlike the biofilms on the skin and intestinal mucosa that fall off by natural process. Thus, we emphasize that the GS and the JE are the weakest leaky point for microbes to invade human body, making the leaky gum just as important as, or even more important than, the leaky gut.

Retinal lipofuscin accumulates with age in the retinal pigment epithelium (RPE) where its fluorescence properties are used to assess the retinal health. It was observed that there is a decrease in lipofuscin fluorescence above the age of 75 years and in early stages of age-related macular degeneration (AMD). The purpose of this study was to investigate the response of lipofuscin isolated from human RPE, and lipofuscin-laden-cells to visible light, and determine whether an abundant component of lipofuscin, docosahexaenoate (DHA) can contribute to lipofuscin fluorescence upon oxidation. Exposure of lipofuscin to visible leads to a decrease of its long-wavelength fluorescence at about 610 nm with concomitant growth of the short-wavelength fluorescence. The emission spectrum of photodegraded lipofuscin exhibits similarity with that of oxidized DHA. Exposure to light of lipofuscin-laden cells leads to loss of lipofuscin granules from cells, while retaining cell viability. The spectral changes of fluorescence in lipofuscin-laden cells resemble those seen during photodegradation of isolated lipofuscin. Our results demonstrate that fluorescence emission spectra together with quantitation of intensity of long-wavelength fluorescence can serve as a marker useful for lipofuscin quantification and for monitoring its oxidation, thereby useful for screening the retina for increased oxidative damage and early AMD-related changes.

The characteristic lesion of primary tuberculosis is the granuloma as is widely studied in human tissues and animal models. Post-primary tuberculosis is different. It develops only in human lungs and begins as a prolonged subclinical obstructive lobular pneumonia that slowly accumulates mycobacterial antigens and host lipids in alveolar macrophages with nearby highly sensitized T cells. After several months, the lesions undergo necrosis to produce a mass of caseous pneumonia large enough to fragment and be coughed out to produce a cavity or be retained as the focus of a post-primary granuloma. Here we extend these findings with the demonstration of mycobacterial antigen, but not AFB, of M. tuberculosis in the cytoplasm of ciliated bronchiolar epithelium and alveolar pneumocytes in association with elements of the programmed death ligand 1 (PD-L1), cyclo-oxygenase (COX)-2, and fatty acid synthase (FAS) pathways in the early lesion. This suggests that M. tuberculosis uses its secreted antigens to coordinate prolonged subclinical development of the early le-sions in preparation for a necrotizing reaction sufficient to produce a cavity, post-primary granulomas and fibrocaseous disease.

The characteristic lesion of primary tuberculosis is the granuloma as is widely studied in human tissues and animal models. Post-primary tuberculosis is different. It develops only in human lungs and begins as a prolonged subclinical obstructive lobular pneumonia that slowly accumulates mycobacterial antigens and host lipids in alveolar macrophages with nearby highly sensitized T cells. After several months, the lesions under necrosis to produce a mass of caseous pneumonia large enough to fragment and be coughed out to produce a cavity or be retained as the focus of a post-primary granuloma. Here we extend these findings with the demonstration of mycobacterial antigen, but not AFB, of M. tuberculosis in the cytoplasm of ciliated bronchiolar epithelium and alveolar pneumocytes in association with elements of the programmed death ligand 1 (PD-L1), cyclo-oxygenase (COX)-2, and fatty acid synthase (FAS) pathways in the early lesion. This suggests that M. tuberculosis use its secreted antigens to coordinate prolonged subclinical development of the early lesions in preparation for a necrotizing reaction sufficient to produce a cavity, post-primary granulomas and fibrocaseous disease

Background: DNA-RNA compounds have shown promising protection against cell oxidative stress. This study aimed to assess the cytotoxicity, protective, or preventive effect of different experimental formulations on oral epithelia’s oxidative stress in vitro. Methods: Reconstituted human oral epithelia (RHOE) were grown air-lifted in a continuous-flow bioreactor. Mouthwash and gels containing DNA-RNA compounds and other bioactive molecules were tested on a model of oxidative stress generated by hydrogen peroxide treatment. Epithelia viability was evaluated using a biochemical MTT-based assay and confocal microscopy; structural and ultrastructural morphology was evaluated by light microscopy and TEM. Results: DNA-RNA showed non-cytotoxic activity and effectively protected against oxidative stress, but not in its prevention. Gel formulation did not express adequate activity compared to the mouthwash. Excipients played a fundamental role in enhancing or even decreasing the bioactive molecules’ effect. Conclusion: A mouthwash formulation with hydrolyzed DNA-RNA effectively protected against oxidative stress without additional enhancement by other bioactive molecules. Active compounds such as hyaluronic acid, β-Glucan, allantoin, bisabolol, ruscogenin, and essential oils showed a protective effect against oxidative stress, which was not synergistic with the one of DNA-RNA. Surfactant agents showed harmful activity against oral epithelia.

The retina is a complex and fragile photosensitive part of the central nervous system which is prone to degenerative diseases leading to permanent vision loss. No proven treatment strategies exist to treat or reverse the degenerative conditions. Recent investigations demonstrate that cell transplantation therapies to replace the dysfunctional retinal pigment epithelial (RPE) cells and or the degenerating photoreceptors (PRs) are viable options to restore vision. Pluripotent stem cells, retinal progenitor cells and somatic stem cells are the main cell sources used for cell transplantation therapies. The success of retinal transplantation based on cell suspension injection is hindered by limited cell survival and lack of cellular integration. Recent advances in material science helped to develop strategies to grow cells as intact monolayers or as sheets on biomaterial scaffolds for transplantation into the eyes. Such implants are found to be more promising than the bolus injection approach. Tissue engineering techniques are specifically designed to construct biodegradable or non-degradable polymer scaffolds to grow cells as a monolayer and construct implantable grafts. The engineered cell construct along with the extracellular matrix formed, can hold the cells in place to enable easy survival, better integration and improved visual function. This article reviews the advances in the use of scaffolds for transplantation studies in animal models and its application in current clinical trials.

Chronic degeneration of the Retinal Pigment Epithelium (RPE) is a precursor to pathological changes in the outer retina. The RPE monolayer, which lies beneath the neuroretina, daily internalises and digests large volumes of spent photoreceptor outer segments. Impaired cargo handling and processing in the endocytic/phagosome and autophagy pathways leads to the accumulation of lipofuscin and N-retinylidene-N-retinylethanolamine aggregates and chemically-modified compounds such as malondialdehyde and 4-hydroxynonenal within RPE. These contribute to increased proteolytic and oxidative stress, resulting in irreversible damage to post-mitotic RPE cells and development of blinding conditions such as Age-related Macular Degeneration, Stargardt disease and Choroideremia. Here, we review how impaired cargo handling in the RPE results in their dysfunction, discuss new findings from our laboratory and consider how newly discovered roles for lysosomes and the autophagy pathway could provide insights into retinopathies. Studies of these dynamic, molecular events have also been spurred on by recent advances in optics and imaging technology. Mechanisms underpinning lysosomal impairment in other degenerative conditions including storage disorders, a-synuclein pathologies and Alzheimer’s disease are also discussed. Collectively, these findings help transcend conventional understanding of these intracellular compartments as simple waste disposal bags to bring about a paradigm shift in the way lysosomes are perceived.

Objectives (Purpose) This study aims to evaluate the outcomes of the Subcrestally Placed Implant (SPI) technique in single molar cases, focusing on biological stability and aesthetics. It proposes a schematic model to elucidate the interplay between the biological stability of soft tissues and bone around the SPI and the morphological requisites that Implant Abutment Prostheses (IAP) must fulfill to effectively replace natural teeth. Materials and methods I examined 20 cases using the SPI technique with Internal Platform Switching (IPS) design implants for single molar replacements to assess their stability. Routine check-ups utilized plain panoramic X-rays to measure changes in crestal bone on the mesial and distal sides. Additionally, 10 cases with CBCT X-rays taken more than one year after the initial surgery underwent a novel 3-dimensional soft tissue analysis (3DSTA). Measurements included placement depths (PD), soft tissue thickness (STT) at central (cPD, cSTT) and peripheral areas (pPD, pSTT), the length of the Transitional Zone (TZ) on mesial, distal, facial, and lingual aspects, and crestal bone thickness (CBT) at buccal and lingual sites. Results Panoramic analyses showed minimal changes in crestal bone (mean changes of pPD were less than 0.1 mm) over an average period of 3.3 years. Average measurements were as follows: cPD was 1.7 mm, pPD was 2.7 mm, cSTT was 0.2 mm, pSTT was 0.6 mm, TZ length was 3.8 mm, buccal CBT was 3.0 mm, and lingual CBT was 3.7 mm. Conclusions CBCT analyses of the topographical relationships between soft tissue and crestal bone with IAP for SPIs demonstrated stable results over an average 3-year period. The consistency in the relationship between crestal bone and surrounding soft tissue can be ascribed to biological structural integrity. The study classified peri-implant soft tissues into subcrestal and supracrestal (transitional zone – TZ) segments, exploring their characteristics through dimensional measurements and assessing mechanical resistance. Further histological study is needed to identify specific features of each segment.

Dehydrolutein accumulates in substantial concentrations in the retina. The aim of this study was to compare antioxidant properties of dehydrolutein with other retinal carotenoids, lutein and zeaxanthin, and their effects on ARPE-19 cells. The time-resolved detection of characteristic singlet oxygen phosphorescence was used to compare the singlet oxygen quenching rate constants of dehydrolutein, lutein, and zeaxanthin. The effects of these carotenoids on photosensitized oxidation were tested in liposomes, where photooxidation was induced by light in the presence of photosensitizers, and monitored by oximetry. To compare the uptake of dehydrolutein, lutein, and zeaxanthin, ARPE-19 cells were incubated with carotenoids for up to 19 days, and carotenoid contents were determined by spectrophotometry in cell extracts. To investigate the effects of carotenoids on phototocytotoxicity, cells were exposed to light in the presence of rose bengal or all-trans-retinal. The results demonstrate that the rate constants for singlet oxygen quenching are 0.77x1010, 0.55x1010, and 1.23x1010 M-1s-1 for dehydrolutein, lutein and zeaxanthin, respectively. Overall, dehydrolutein is similar to lutein or zeaxanthin in protection of lipids against photosensitized oxidation. ARPE-19 cells accumulate substantial amounts of both zeaxanthin and lutein but no detectable amounts of dehydrolutein. Cells pre-incubated with carotenoids are equally susceptible to photosensitized damage as cells without carotenoids. Carotenoids provided to cells together with the extracellular photosensitizers offer partial protection against photodamage. In conclusion, the antioxidant properties of dehydrolutein are similar to lutein and zeaxanthin. The mechanism responsible for its lack of accumulation in ARPE-19 cells deserves further investigation.

Epithelial characteristics underlying the differential susceptibility of chronic asthma to SARS-CoV-2 (COVID-19) and other viral infections are currently unclear. By revisiting transcriptomic data from patients with Th2 low versus Th2 high asthma, as well as mild, moderate and severe asthmatics, we characterized the changes in expression of human coronavirus and influenza viral entry genes relative to sex, airway location and disease endotype. We found sexual dimorphism in expression of COVID-19 genes ACE2, TMPRSS2, TMPRSS4, and SLC6A19. ACE2 receptor downregulation occurred specifically in females in Th2 high asthma, while proteases broadly assisting coronavirus and influenza viral entry, TMPRSS2 and TMPRSS4, were highly upregulated in both sexes. Overall, changes in COVID-19 gene expression were specific to Th2 high molecular endotype of asthma, and different by asthma severity and airway location. The downregulation of ACE2 (COVID-19, SARS) and ANPEP (HCoV-229E) viral receptors correlated with loss of club and ciliated cells in Th2 high asthma, while the increase in DPP4 (MERS-CoV), ST3GAL4, and ST6GAL1 (influenza) associated with an increase in goblet and basal activated cells. Overall, this study elucidates sex, airway location, disease endotype and changes in epithelial heterogeneity as factors underlying asthmatic susceptibility, or lack thereof, to COVID-19.

Given the accelerating scientific, clinical and consumer interest in highly-prevalent functional gastrointestinal disorders, appropriate therapeutic strategies are needed to address the many aspects of digestive dysfunction. Accumulating evidence for the crucifer-derived bioactive molecule, sulforaphane in upstream cellular defence mechanisms highlights its potential as a therapeutic candidate in targeting functional gastrointestinal conditions together with systemic disorders. This article catalogues the evolution of and rationale for a hypothesis that utilises multifunctional sulforaphane as the initial step in restoring the ecology of the gut ecosystem; it does this primarily by targeting the functions of intestinal epithelial cells. A growing body of work has identified the colonocyte as the driver of dysbiosis, so that targeting gut epithelial function could provide an alternative to targeting the microbes themselves for remediation of microbial dysbiosis. The hypothesis discussed herein has evolved over several years and is supported by case studies showing the application of sulforaphane in gastrointestinal disorders, related food intolerance and several systemic conditions. To our knowledge, this is the first time the effects of sulforaphane have been reported in a clinical environment where several of its key properties within the gut ecosystem appear to be related to its nutrigenomic effects on gene expression.

Mitochondrial dysfunction and oxidative stress are thought to be relevant to the pathogenesis of age-related macular degeneration (AMD). Glutathione (GSH) homeostasis fulfills a number of important roles in mitochondria, such as maintenance of mitochondrial DNA and respiratory competency of cells. Although the transport of mitochondrial GSH (mGSH) is not fully understood, increasing evidence from non-ocular tissues suggests that OGC (2-oxoglutarate carrier, SLC25A11) and DIC (dicarboxylate carrier, SLC25A10) are involved in mGSH transport. However, whether OGC and DIC mediate the transfer of GSH into the mitochondria of retinal pigment epithelial cells (RPE) remains unknown. Thus, we investigated the expression, localization, and function of OGC and DIC in human RPE (hRPE) in relation to oxidative stress and GSH. Both OGC and DIC are expressed in hRPE and are localized in mitochondria. We also found a dose and time-dependent decrease of OGC and DIC expression under oxidative stress and increased expression in polarized RPE. Our data show that the downregulation of OGC and DIC resulted in increased apoptosis and mGSH depletion which can be overcome by co-treatment with GSH-MEE. These findings suggest that overexpression of OGC and DIC may be an effective strategy to decrease susceptibility to mitochondrial toxicants by elevation of mGSH.

Age-related macular degeneration is one of the most common causes of blindness, and the incidence exhibits profound racial bias, occurring most frequently in Caucasians. A primary cell type affected in the disease is the retinal pigment epithelium, but the etiology is unclear. The end 10% of the photoreceptor outer segments are shed each day, and the underlying retinal pigment epithelium engulfs, digests, and recycles molecules back to the sensory retina. In previous work, we showed that GPR143 signaling in response to L-DOPA may be effective in the prevention or delay of age-related macular degeneration. In this study, we explore a novel potential effector of GPR143 signaling, that of outer segment uptake and digestion. Using isolated outer segments, labelled with a pH-sensitive marker to fluoresce in lysosomes, we show that GPR143 signaling does not impact outer segment uptake, but does have a significant effect on subsequent degradation. Interestingly, GPR143 signaling did not affect the digestive capacity of the cells, marked by total proteolytic capacity and cathepsin D activity. Rather, our data suggest GPR143 improved endosomal trafficking efficiency of the phagocytosed outer segments to the lysosome. This result is similar to the effect we previously reported for GPR143 on exosome release from the endosomal compartment. Our data illustrate that GPR143 is active in endosomal traffic A single paragraph of about 200 words maximum. For research articles, abstracts should give a pertinent overview of the work. We strongly encourage authors to use the following style of structured abstracts, but without headings: (1) Background: Place the question addressed in a broad context and highlight the purpose of the study; (2) Methods: briefly describe the main methods or treatments applied; (3) Results: summarize the article’s main findings; (4) Conclusions: indicate the main conclusions or interpretations. The abstract should be an objective representation of the article and it must not contain results that are not presented and substantiated in the main text and should not exaggerate the main conclusions.

The oral mucosa represents a defense between the external environment and the rest of the body and encompasses several antimicrobial and antiviral mechanisms. Oral mucosal cells are constantly bathed in hypotonic saliva (normally one-third tonicity compared to plasma) and are repeatedly exposed to environmental stresses of tonicity, temperature and pH by the drinks we imbibe (e.g. hypotonic: water, tea, coffee; hypertonic: assorted fruit juices, red wines), as well as of diverse microbial and viral flora. In the mouth, the broad-spectrum antiviral mediator MxA (a dynamin-family large GTPase) is constitutively expressed in healthy periodontal tissues, and also induced by Type III interferons (e.g. IFN-λ1). Endogenously induced human MxA and exogenously expressed human GFP-MxA formed membraneless biomolecular condensates in the cytoplasm of oral carcinoma cells (OECM1 cell line). These condensates likely represent storage granules in equilibrium with antivirally active dispersed MxA. Remarkably, cytoplasmic MxA condensates were exquisitely sensitive sensors of hypotonicity – the condensates in oral epithelium disassembled within 1-2 min of exposure of cells to saliva-like one-third hypotonicity, and spontaneously reassembled in the next 4-7 min. OECM1 cells preloaded with calcein-AM (a reporter of cytosolic “macromolecular crowding”) confirmed unquenching and then requenching of calcein fluorescence during this process. Hypertonicity had little effect on MxA condensates. The spontaneous reassembly of GFP-MxA condensates in oral epithelial cells even under continuous saliva-like hypotonicity was slowed by the protein phosphatase inhibitor cyclosporin A (CsA) and by the K-channel blocker tetraethylammonium chloride (TEA) suggestive of the involvement of the volume-sensitive WNK kinase-protein phosphatase (PTP)-K-Cl cotransporter (KCC) pathway in the regulated volume decrease (RVD) during condensate reassembly in oral cells. Thus, physiologically, hypotonic drinks (water, tea, coffee) trigger a rapid deployment of antiviral MxA throughout the cytoplasm of oral epithelial cells, with subsequent salvage of MxA back into storage granules/condensates.

We wanted to investigate the current knowledge on the impact of diet on anti-TNF response in inflammatory bowel diseases (IBD), to identify dietary factors that warrant further investigations in relation to anti-TNF treatment response, and, finally, to discuss potential strategies for such investigations. PubMed was searched using specified search terms. One small prospective study on diet and anti-TNF treatment in 56 patients with CD found similar remission rates after 56 weeks among 32 patients with good compliance that received concomitant enteral nutrition and 24 with poor compliance that had no dietary restrictions (78% versus 67%, p = 0.51). A meta-analysis of 295 patients found higher odds of achieving clinical remission and remaining in clinical remission among patients on combination therapy with specialised enteral nutrition and Infliximab (IFX) compared with IFX monotherapy (OR 2.73; 95% CI: 1.73–4.31, p < 0.01, OR 2.93; 95% CI: 1.66–5.17, p < 0.01, respectively). In conclusion, evidence-based knowledge on impact of diet on anti-TNF treatment response for clinical use is scarce. Here we propose a mechanism by which Western style diet high in meat and low in fibre may promote colonic inflammation and potentially impact treatment response to anti-TNF drugs. Further studies using hypothesis-driven and data-driven strategies in observational, animal and interventional studies are warranted.

Increased screen time during the COVID-19 pandemic and the accelerated incorporation of technology into daily practices have directly contributed to the increased prevalence of eye disease. The human eye is not built for continual technological use and must adjust to exposure to digital screens. Overexposure to technology can result in eye strain and an increased risk of eye diseases such as myopia with complications later in life, including retinal tears, cataracts, and macular degeneration. As vision and ocular diseases become more prevalent, the study of eye diseases, including their causes and treatments, is especially relevant. There is a need to prevent ocular diseases before they become a burden to individuals, their families, and their communities by better understanding the pathophysiology of ocular diseases. Several ocular diseases are thought to be caused by imbalances in reactive oxygen species (ROS) and autophagy. ROS refers to a class of highly reactive oxygen-containing molecules that can undergo damaging reactions with other molecules in the cell. Autophagy is a cellular process of self-eating whereby damaged, harmful, or dead material in cells is broken down to maintain cellular homeostasis. This paper discusses the role of ROS and autophagy in the pathogenesis of computer vision syndrome (CVS), digital eye strain (DES), myopia, cataracts, glaucoma, diabetic retinopathy (DR), age-related macular degeneration (AMD), optic nerve crush injury (OCN), optic nerve gliomas, and retinoblastoma. Lifestyle changes such as limiting screen time, ensuring adequate exposure to evening sunlight, and using blue light protection measures or protective eyewear are important in the prevention of eye disease. Nutrition also contributes significantly to eye health. A balanced diet rich in vitamins and antioxidants may help to prevent ROS and autophagy imbalance-induced eye disease. Medical and surgical treatments become necessary when preventative measures fail. This paper also addresses how government measures to decrease the onset of eye disease, including targeted programs to increase access to fresh vegetables and fruits in food deserts, are a critical macro-level avenue to reduce eye disease prevalence in the US, which according to the National Eye Institute, costs $139 billion yearly.