Vascular Endothelial Cadherin Research Articles

Chitosan/Alginate-Based Hydrogel Loaded With VE-Cadherin/FGF as Scaffolds for Wound Repair in Different Degrees of Skin Burns.

Burns are complex traumatic injuries that lead to severe physical and psychological problems due to the prolonged healing period and resulting physical scars. Owing to their versatility, hydrogels can be loaded with various functional factors, making them promising wound dressings. However, many hydrogel dressings cannot support cell survival for a long time, thereby delaying the process of tissue repair. Herein, based on chitosan (CS)/alginate (SA)/poly(ethylene glycol) diacrylate (PEGDA), a basic hydrogel with hemostasis and antibacterial properties was prepared, and loaded with vascular endothelial cadherin (VE-cadherin) and fibroblast growth factors (FGF) to promote the co-culture of various skin cells, suitable for treating various skin injury types: (1) Construct a three-dimensional microenvironment conducive to the release of drugs and factors using natural biological macromolecules CS/SA. (2) Promote the cell growth by loading growth factors. (3) Establish skin burn models of different degrees and observe the repair process. From the results, the 3D microenvironment provided by hydrogel could support the active growth of cells for 12 days. Furthermore, deep burns with full-thickness skin were substantially repaired within about 24 days. Collectively, CS/SA hydrogel containing VE-cadherin and FGF can promote tissue healing in wounds with necrotic tissue, making it an ideal candidate for burn treatment.

Advances in the Study of the Role of Vascular Endothelial Cell Cadherin in Diabetic Retinopathy

Advances in the Study of the Role of Vascular Endothelial Cell Cadherin in Diabetic Retinopathy

Salivary adenoid cystic carcinoma-derived α2,6-sialylated extracellular vesicles increase vascular permeability by triggering ER-stress in endothelial cells and promote lung metastasis.

Salivary adenoid cystic carcinoma (SACC) tends to metastasize to the lungs in the early stages of the disease. Factors secreted by the primary tumor can induce the formation of a supportive microenvironment in distant organs prior to metastasis, a process known as pre-metastatic niche (PMN) formation. Extracellular vesicles (EVs) participate in PMN formation. In this study, α2,6-sialylation of EVs derived from SACC cells with high metastatic potential increased vascular permeability, thereby facilitating tumor metastasis to the lungs. Mechanistic studies indicated that EV α2,6-sialylation triggers protein kinase R-like endoplasmic reticulum kinase (PERK)-eukaryotic initiation factor 2α (eIF2α)-dependent activation of endoplasmic reticulum (ER) stress in the endothelium, leading to the disruption of vascular endothelial cadherin membrane expression. Sialidase or an ER stress inhibitor rescued vascular permeability induced by SACC EVs, which decreased the number of SACC cells extravasating into the lungs both in vitro and in vivo. This study identified a critical role of α2,6-sialylation of SACC EVs in lung metastasis. The findings indicate that EV α2,6-sialylation-induced ER stress in endothelial cells might be a therapeutic target for preventing SACC lung metastasis.

Porphyromonas gingivalis outer membrane vesicles increase vascular permeability by inducing stress fiber formation and degrading vascular endothelial-cadherin in endothelial cells.

Porphyromonas gingivalis (Pg) is a keystone bacterium associated with systemic diseases, such as diabetes mellitus and Alzheimer's disease. Outer membrane vesicles (OMVs) released from Pg have been implicated in systemic diseases by delivering Pg virulence factors to host cells in distant organs and inducing cellular dysfunction. Pg OMVs also have the potential to enter distant organs via the bloodstream. However, the effects of PgOMVs on the vascular function are poorly understood. Here, we showed that Pg OMVs increase vascular permeability by promoting stressfiber formation and lysosome/endosome-mediated vascular endothelial-cadherin (VEc) degradation in human umbilical vein endothelial cells (HUVECs) and human pulmonary microvascular endothelial cells (HPMECs). F-actin, visualized via fluorescein isothiocyanate-phalloidin, became thicker and longer, leading to the formation of radical stress fibers in response to Pg OMVs in HUVECs and HPMECs. Western blotting and quantitative real-time polymerase chain reaction analyses revealed that PgOMVs decreased VEc protein levels in a gene-independent manner. PgOMVs enhanced vesicular VEc accumulation in the cytoplasm around lysosome-associated membrane protein 1-positive structures during pretreatment with the lysosomal inhibitor chloroquine. This suggests that PgOMVs decrease VEc protein levels by accelerating their internalization and degradation via lysosomes and endosomes. A27632 inhibition of Rho kinases impaired the Pg OMV-induced stress fiber formation and VEc degradation, resulting in the recovery of hyperpermeability. These findings provide new insights into the pathogenesis of systemic diseases that are associated with periodontal diseases.

Effect of imatinib on lipopolysaccharide‑induced acute lung injury and endothelial dysfunction through the P38 MAPK and NF-κB signaling pathways in vivo and in vitro.

The primary purpose of this study was to demonstrate the preventive effects of imatinib (IMA) on lipopolysaccharide (LPS)-induced inflammation in a mouse model of acute lung injury (ALI) and human umbilical vascular endothelial cells. LPS stimulation for 24h induced ALI and cell inflammation. The pathological results of the lungs were evaluated using the wet/dry weight ratio, pulmonary vascular permeability measurements, and myeloperoxidase immunohistochemistry. The expression of pro-inflammatory mediators was analyzed using RT-PCR and enzyme-linked immunosorbent assay. Protein levels were analyzed using western blotting. The structure of cell junctions was detected using immunofluorescence. IMA improved LPS-induced pulmonary pathological damage and reduced the lung wet/dry weight ratio and myeloperoxidase expression in the lung tissue. IMA decreased bronchoalveolar lavage fluid inflammatory cell count and the release of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and monocyte chemotactic protein 1 (MCP-1) in the blood. Pretreatment of human umbilical vascular endothelial cells with IMA significantly attenuated LPS-induced actin stress fiber formation and vascular endothelial-cadherin disruption. In addition, IMA downregulated the mRNA abundances of vascular cell adhesion molecule 1, intercellular adhesion molecule 1, IL-1β, IL-6, and tumor necrosis factor-α(TNF-α) expression. The phosphorylation of p65, nuclear factor-kappa B inhibitor alpha (IκBα), p38, extracellular signal-regulated kinase, and Jun N-terminal kinase induced by LPS were attenuated after IMA treatment in vivo and in vitro. IMA modulates the nuclear factor-kappa B and mitogen-activated protein kinase signaling pathways and the production of pro-inflammatory cytokines to prevent cellular damage due to LPS infection. These results indicate that IMA may be a potential modulator of LPS-induced ALI.

Correlation between pre-operative VE-cadherin and DLL4 and the maturation after primary arteriovenous fistula in uremic patients.

Uremic patients require dialysis to replace the declined kidney function, and arteriovenous fistula (AVF) is a commonly used dialysis access route. Our study aimed to explore vascular endothelial cells cadherin (VE-cadherin) and Delta-like ligand 4 (DLL4) expression in uremic patients undergoing primary AVF surgery and their correlation with AVF maturation. We conducted a prospective study that included n = 55 voluntary uremic patients receiving their initial AVF procedure for renal replacement therapy, subjects were divided into a mature group and a failure group based on whether the AVF matured within 3 months post-operatively. We analyzed the association of VE-cadherin and DLL4 with AVF maturation by examining their expression levels in serum and the endothelium of cephalic veins. Pre-operative serum VE-cadherin, in the mature group measured 125.07 (106.77-167.65) ng/L, and DLL4 was 92.78 (83.83-106.72) pg/mL, while the failure group had VE-cadherin at 95.40 (79.03-107.16) ng/L (P = 0.001), and DLL4 at 60.42 (43.98-80.15) pg/mL with a statistical significant; (P = 0.002), binary logistic regression analysis indicated a significant association between cephalic vein diameter, VE-cadherin, DLL4 levels, and AVF immaturity (P = 0.024, P = 0.014 respectively). Immunohistochemical staining showed slightly higher VE-cadherin levels in the mature group than in the failure group (P = 0.366). DLL4 was primarily located in the cell membrane and cytoplasm, concentrated in the inner membrane, with significantly higher levels in the mature group compared to the failure group (P = 0.027). The failure group exhibited lower levels of VE-cadherin and DLL4 in serum and vascular tissue, these results suggest that VE-cadherin and DLL4 might play pivotal regulatory roles in the onset and the progression of fistula immaturity, potentially serving as promising targets for future interventions.

Occlusive lesions of retinal vessels: etiological and patogenetic factors

Background. Vascular pathology of the organ of vision is one of the most urgent problems of ophthalmology, as it is the main cause of vision loss and vision loss. Retinal vein occlusion ranks second after diabetic retinopathy in the world among vascular causes of vision loss. In a significant risk group for the occurrence of occlusions of the retinal vessels are patients with cardiovascular diseases. Today, treatment of patients with coronary heart disease and patho­logy of heart valves is impossible without surgical interventions, most of which require the use of artificial circulation (AC). During the operation of the AC due to prolonged hypothermia, hemodilution, prolonged hypotension, anemia, development of ophthalmologic complications in the early postoperative period is possible. The purpose of the study was to investigate etiological and pathogenetic factors of occlusive lesions of retinal vessels. Mate­rials and methods. The search for sources of Ukrainian and foreign literature for the ana­lytical review was conducted keywords using the open medical scientific database PubMed (USA). At the first stage, 211 sources were selected, of which 66 were selected for this article. Results. Occlusion of the central retinal vein (CVO) deve­lops in 214 people per 100,000 population, mainly in people over 65 years of age. The frequency of branh retinal vein occlusions (BRVO) is 67.2%, of which 82.4% is a occlusion of the superior temporal branch. The main risk factors of CVO are age, hypertension, diabetes, atherosclerosis, glaucoma, coronary heart disease. A small number of sources are found in the literature regarding complications from the organ of vision in patients after cardiac surgery with AC such us thromboembolism of retinal vessels, optic ischemic optic neuropathy, retinal ischemia, optic nerve atrophy, retinal detachment, proliferative vitreoretinopathy. The authors' research showed a multiple increase in blood markers of endothelial dysfunction, including vascular endothelial cadherin (VE-cadherin, VE-C) after surgery. Conclusions. Diseases of the organ of vision due to general or local blood circulation disorders account for 10 to 28%, 2.6% of which lead to blindness. There is a relationship between occlusive lesions of retinal veins and cardiovascular diseases. The main reasons for the development of retinal vein occlusion after cardiac surgery with coronary artery disease are acute inflammation occurring during and immediately after surgery and endothelial dysfunction.

Curcumin Inhibits Vasculogenic Mimicry via Regulating ETS-1 in Renal Cell Carcinoma.

Metastatic renal cell carcinoma (RCC) poses a huge challenge once it has become resistant to targeted therapy. Vasculogenic mimicry (VM) is a novel blood supply system formed by tumor cells that can circumvent molecular targeted therapies. As one of the herbal remedies, curcumin has been demonstrated to play antineoplastic effects in many different types of human cancers; however, its function and mechanism of targeting VM in RCC remains unknown. Here, in the work, we explored the role of curcumin and its molecular mechanism in the regulation of VM formation in RCC. RNA-sequencing analysis, immunoblotting, and immunohistochemistry were used to detect E Twenty Six-1(ETS-1), vascular endothelial Cadherin (VE-Cadherin), and matrix metallopeptidase 9 (MMP9) expressions in RCC cells and tissues. RNA sequencing was used to screen the differential expressed genes. Plasmid transfections were used to transiently knock down or overexpress ETS-1. VM formation was determined by tube formation assay and animal experiments. CD31-PAS double staining was used to label the VM channels in patients and xenograft samples. Our results demonstrated that VM was positively correlated with RCC grades and stages using clinical patient samples. Curcumin inhibited VM formation in dose and time-dependent manner in vitro. Using RNA-sequencing analysis, we discovered ETS-1 as a potential transcriptional factor regulating VM formation. Knocking down or overexpression of ETS-1 decreased or increased the VM formation, respectively and regulated the expression of VE-Cadherin and MMP9. Curcumin could inhibit VM formation by suppressing ETS-1, VE-Cadherin, and MMP9 expression both in vitro and in vivo. Our finding might indicate that curcumin could inhibit VM by regulating ETS-1, VE-Cadherin, and MMP9 expression in RCC cell lines. Curcumin could be considered as a potential anti-cancer compound by inhibiting VM in RCC progression.

Serum Levels of Soluble Vascular Endothelial Cadherin among COVID-19 Children

Abstract Background COVID-19 is an endothelial disease, and the consequent endotheliopathy is responsible for inflammation, cytokine storm, oxidative stress, and coagulopathy. Vascular endothelial cadherin (VE- cadherin) is a strictly endothelial specific adhesion molecule located at junctions between endothelial cells. Aim: serum levels of VE-cadherin was assessed as a marker of endothelial dysfunction among COVID-19 patients compared with healthy controls. Methods Thirty patients with COVID-19 with median age 5.6 (3.3-7.0) years old were enrolled. They were compared with 30 healthy controls. Covid-19 polymerase chain reaction, Covid-19 antibodies, complete blood count, blood gases, C-reactive protein, D-dimer, lactate dehydrogenase, serum ferritin and VE-cadherin levels were assessed. Results VE-cadherin levels were significantly higher in COVID-19 patients compared with healthy controls. There was a significant negative correlation between VE-cadherin and platelet count while VE-cadherin was positively correlated to creatinine level. Conclusion VE-cadherin levels are elevated in children and adolescents with COVID- 19 suggesting the presence of endothelial dysfunction. VE-cadherin levels are mainly related to lung and kidney injury in COVID-19 patients.

Expressions of vascular endothelial cadherin and soluble Fas ligand in patients with viral myocarditis and their correlations

Abstract Background We aimed to explore the expressions of vascular endothelial cadherin (VE-cadherin) and soluble Fas ligand (sFasL) in patients suffering from viral myocarditis (VMC), and the correlations between them. Methods Fifty VMC patients diagnosed between January 2022 and December 2023 were selected as the subjects (experimental group), and an equal number of participants receiving health examination were included as a control group. The experimental group was then subdivided into mild, moderate, and severe subgroups according to their clinical symptoms. Peripheral blood samples were collected to detect the serum levels of VE-cadherin and sFasL through enzyme-linked immunosorbent assay, and the differences in their levels were compared. The clinical baseline data and cardiac function indicators (left ventricular systolic function as well as early and late left ventricular diastolic function) were acquired. Results The ejection fraction of the inferior ventricular septum showed no significant difference between the two groups (p>0.05), but there were significant differences in the remaining indicators (p<0.05). The levels of VE-cadherin and sFasL in the experimental group were significantly higher than those in the control group (p<0.05). The severe VMC group had significantly elevated VE-cadherin and sFasL levels compared with those of moderate and mild groups, and the moderate group had significantly raised levels compared to those of the mild group (p<0.05). VE-cadherin level was positively correlated with sFasL level. Conclusions The elevation of serum VE-cadherin and sFasL levels may be associated with myocardial inflammatory response and cardiac function damage. VE-cadherin and sFasL are potential biomarkers of VMC for early diagnosis and treatment evaluation.

Ameliorating lipopolysaccharide induced acute lung injury with Lianhua Qingke: focus on pulmonary endothelial barrier protection.

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) has long posed challenges in clinical practice, lacking established preventive and therapeutic approaches. Lianhua Qingke (LHQK), a patented traditional Chinese medicine (TCM), has been found to have anti-inflammatory effects for ameliorating ALI/ARDS induced by lipopolysaccharide (LPS). This study aimed to investigate the effects and potential mechanisms of LHQK on endothelial protection in LPS-induced ALI/ARDS in vivo and in LPS-induced human pulmonary microvascular endothelial cells (HPMECs) injury in vitro. In the animal experiment, we induced an ALI/ARDS model by intratracheal injection of LPS (5 mg/mL). LHQK (3.7 g/kg/d for low dose and 7.4 g/kg/d for high dose) or dexamethasone (DEX) (5 mg/kg/d) was administered to mice 3 days prior to LPS treatment. In the in vitro experiments, HPMECs were pretreated with LHQK at concentrations of 125 and 250 µg/mL for 2 hours before being stimulated with LPS (10 µg/mL). We employed lung function test, measurement of lung index, hematoxylin and eosin (H&E) staining, bronchoalveolar lavage fluid (BALF) cell counts, and inflammatory cytokine levels to assess the therapeutic effect of LHQK. Additionally, the extravasation assay of fluorescein isothiocyanate-dextran (FITC-dextran) dye and the transmembrane electrical resistance (TEER) assay were used to evaluate endothelial barrier. Barrier integrity and relevant protein validation were assessed using immunofluorescence (IF) and Western blot analyses. Furthermore, network pharmacology analysis and cellular level screening were employed to predict and screen the active ingredients of LHQK. Compared to the LPS group, LHQK significantly improved lung function, mitigated lung pathological injuries, reduced inflammatory cells and inflammatory cytokines [tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6] levels in BALF, and inhibited the expression of vascular cell adhesion molecule-1 (VCAM-1), attenuated LPS-induced pulmonary oedema and FITC-dextran permeability, and enhanced the expression of vascular endothelial-cadherin (VE-cadherin) and occludin. In vitro, LHQK attenuated LPS-induced HPMECs injury by elevating TEER values and enhancing VE-cadherin and occludin protein levels. Finally, network pharmacology analysis and cellular level validation identified potential active ingredients of LHQK. In summary, LHQK can mitigate LPS-induced inflammatory infiltration, pulmonary edema, and pulmonary vascular endothelial barrier dysfunction in the context of ALI/ARDS. This is achieved by decreasing the levels of VCAM-1, and increasing the expression levels of barrier-associated junctions, such as VE-cadherin and occludin. Consequently, LHQK exhibits promising therapeutic potential in preventing the progression of ALI/ARDS.

Mechanistic insights into the impact of WIN 55, 212-2, a synthetic cannabinoid, on adhesion molecules PECAM-1 and VE-cadherin in HeLa cells: implications on cancer processes

The endocannabinoid (eCB) system comprises endogenous ligands, cannabinoid receptors (CBRs), and their regulatory proteins; its alteration leads to many diseases including cancer. Thus, becomes a therapeutic target for synthetic cannabinoids aimed to control cancer cell proliferation, migration, adhesion, and invasion. However, little is known about adhesion molecules regulation through CBRs activation. The aim of this study was to evaluate the effects of a CB1/CB2 agonist, WIN-55, 212-2 (WIN), on the regulation of adhesion molecules platelet endothelial cell adhesion molecule-1 (PECAM-1) and vascular endothelial cadherin (VE-cadherin) in HeLa cells. CBRs expression was evaluated by immunofluorescence staining in HeLa cells and cell viability (thiazolyl blue tetrazolium bromide), cell adhesion (crystal violet), adhesion molecules expression and location (Western blot and immunofluorescence staining assays) were all assessed on cells treated with different WIN concentrations. Receptors CB1, CB2, and G-protein-coupled receptor 55 were expressed in HeLa cells. Additionally, biphasic effects were observed in their metabolic activity and adhesive properties: low WIN concentrations resulted in significant increases whereas, high ones decreased them compared to controls (p < 0.0001), demonstrating that WIN elicits opposite effects depending on the concentration and exposure time. PECAM-1 was detected in HeLa cell’s cytoplasm, membrane, and perinuclear region, whereas VE-cadherin had a nuclear distribution. There were no significant differences in PECAM-1 and VE-cadherin expression and location, suggesting that WIN does not modulate these proteins. These findings support the potential use of WIN due to its anticancer properties without dysregulating adhesion molecules. WIN possible contribution to inhibit cancer progression should be further investigated.

Simulated microgravity-induced dysregulation of cerebrospinal fluid immune homeostasis by disrupting the blood-cerebrospinal fluid barrier.

The blood-cerebrospinal fluid barrier (BCSFB) comprises the choroid plexus epithelia. It is important for brain development, maintenance, function, and especially for maintaining immune homeostasis in the cerebrospinal fluid (CSF). Although previous studies have shown that the peripheral immune function of the body is impaired upon exposure to microgravity, no studies have reported changes in immune cells and cytokines in the CSF that reflect neuroimmune status. The purpose of this study is to investigate the alterations in cerebrospinal fluid (CSF) immune homeostasis induced by microgravity and its mechanisms. This research is expected to provide basic data for brain protection of astronauts during spaceflight. The proportions of immune cells in the CSF and peripheral blood (PB) of SMG rats were analyzed using flow cytometry. Immune function was evaluated by measuring cytokine concentrations using the Luminex method. The histomorphology and ultrastructure of the choroid plexus epithelia were determined. The concentrations of intercellular junction proteins in choroid plexus epithelial cells, including vascular endothelial-cadherin (VE-cadherin), zonula occludens 1 (ZO-1), Claudin-1 and occludin, were detected using western blotting and immunofluorescence staining to characterize BCSFB injury. We found that SMG caused significant changes in the proportion of CD4 and CD8 T cells in the CSF and a significant increase in the levels of cytokines (GRO/KC, IL-18, MCP-1, and RANTES). In the PB, there was a significant decrease in the proportion of T cells and NKT cells and a significant increase in cytokine levels (GRO/KC, IL-18, MCP-1, and TNF-α). Additionally, we observed that the trends in immune markers in the PB and CSF were synchronized within specific SMG durations, suggesting that longer SMG periods (≥21 days) have a more pronounced impact on immune markers. Furthermore, 21d-SMG resulted in ultrastructural disruption and downregulated expression of intercellular junction proteins in rat choroid plexus epithelial cells. We found that SMG disrupts the BCSFB and affects the CSF immune homeostasis. This study provides new insights into the health protection of astronauts during spaceflight.

Linc-ROR Modulates the Endothelial-Mesenchymal Transition of Endothelial Progenitor Cells through the miR-145/Smad3 Signaling Pathway

The endothelial-mesenchymal transition (EndMT) of endothelial progenitor cells (EPCs) plays a notable role in pathological vascular remodeling. Emerging evidence indicated that long non-coding RNA-regulator of reprogramming (linc-ROR) can promote epithelial-mesenchymal transition (EMT) in a variety of cancer cells. Nevertheless, the function of linc-ROR in EPC EndMT has not been well elucidated. The present study investigated the effect and possible mechanisms of function of linc-ROR on the EndMT of EPCs. A linc-ROR overexpression lentiviral vector (LV linc-ROR) or a linc-ROR short hairpin RNA lentiviral vector (LV-shlinc-ROR) was used to up or downregulate linc-ROR expression in EPCs isolated from human umbilical cord blood. Functional experiments demonstrated that LV-linc-ROR promoted the proliferation and migration of EPCs, but inhibited EPC angiogenesis in vitro. In the meantime, reverse transcription-quantitative PCR and western blotting results showed that the expression of the endothelial cell markers vascular endothelial-cadherin and CD31 was decreased, while the expression of the mesenchymal cell markers α-smooth muscle actin and SM22α was increased at both mRNA and protein levels in LV-linc-ROR-treated EPCs, indicating that linc-ROR induced EPC EndMT. Mechanistically, the dual-luciferase reporter assay demonstrated that microRNA (miR/miRNA)-145 was a direct target of linc-ROR, and miR-145 binds to the 3’-untranslated region of Smad3. Moreover, LV-shlinc-ROR increased the expression of miR-145, but decreased the expression of Smad3. In conclusion, linc-ROR promotes EPC EndMT, which may be associated with the miR-145/Smad3 signaling pathway.

Notch transcriptional target tmtc1 maintains vascular homeostasis

Proper lung function requires the maintenance of a tight endothelial barrier while simultaneously permitting the exchange of macromolecules and fluids to underlying tissue. Disruption of this barrier results in an increased vascular permeability in the lungs, leading to acute lung injury. In this study, we set out to determine whether transcriptional targets of Notch signaling function to preserve vascular integrity. We tested the in vivo requirement for Notch transcriptional signaling in maintaining the pulmonary endothelial barrier by using two complementary endothelial-specific Notch loss-of-function murine transgenic models. Notch signaling was blocked using endothelial-specific activation of an inhibitor of Notch transcriptional activation, Dominant Negative Mastermindlike (DNMAML; CDH5CreERT2), or endothelial-specific loss of Notch1 (Notch1f/f; CDH5CreERT2). Both Notch mutants increased vascular permeability with pan-Notch inhibition by DNMAML showing a more severe phenotype in the lungs and in purified endothelial cells. RNA sequencing of primary lung endothelial cells (ECs) identified novel Notch targets, one of which was transmembrane O-mannosyltransferase targeting cadherins 1 (tmtc1). We show that tmtc1 interacts with vascular endothelial cadherin (VE-cadherin) and regulates VE-cadherin egress from the endoplasmic reticulum through direct interaction. Our findings demonstrate that Notch signaling maintains endothelial adherens junctions and vascular homeostasis by a transcriptional mechanism that drives expression of critical factors important for processing and transport of VE-cadherin.

A (poly)phenol-rich diet reduces serum and faecal calprotectin in older adults with increased intestinal permeability: the MaPLE randomised controlled trial

BackgroundOlder subjects are at risk of elevated intestinal permeability (IP) which can lead to immune system activation and low-grade systemic inflammation. Dietary changes are a potential strategy to reduce IP. The MaPLE project evaluated the hypothesis that increasing (poly)phenol intake would beneficially impact on several important markers and pathways related to IP. The objective of the present study was to assess the effects of the MaPLE (poly)phenol-rich diet (PR-diet) on additional IP-related biomarkers and any relationships between biomarker responses.MethodsA randomised, controlled, crossover study was performed involving 51 participants (≥ 60 y) with increased IP, as determined by serum zonulin levels. Participants were randomly assigned to one of two intervention groups: a control diet (C-diet) or a PR-diet. Each intervention lasted 8 weeks and was separated by an 8-week washout period. For the present study, serum and faecal samples were used to measure zonula occludens-1 (ZO-1), occludin, adiponectin, calprotectin, faecal calprotectin, soluble cluster of differentiation 14 (sCD14), interleukin-6 receptor (IL-6R), and vascular endothelial-cadherin (VEC) levels using quantitative ELISA assays. Data were analysed using ANOVA, and Spearman and network correlation analysis were performed to identify the relationship among biomarkers at baseline.ResultsAmong the different markers analysed, a significant reduction was observed for faecal and serum calprotectin (p = 0.0378 and p = 0.0186, respectively) following the PR-diet, while a significant increase in ZO-1 was found (p = 0.001) after both the intervention periods (PR-diet and C-diet). In addition, a time effect was observed for VEC levels showing a reduction (p = 0.038) following the PR-diet. Based on network correlation analysis, two clusters of correlations were identified: one cluster with high levels of serum calprotectin, faecal calprotectin, sCD14, interleukin (IL)-6, tumor necrosis factor (TNF)-α, C-reactive protein (CRP) and bacterial DNAemia (16 S rRNA gene copies), with potential inflammatory-induced intestinal permeability. Differently, the other cluster had high levels of serum occludin, IL-6R, soluble intercellular adhesion molecule-1 (sICAM-1) and VEC, with potential inflammatory-induced endothelial dysfunction.ConclusionsOverall, this study provides further support to the hypothesis that a (poly)phenol-rich diet may help to ameliorate intestinal permeability-associated conditions. In this regard, calprotectin might represent a promising biomarker since it is a protein that typically increases with age and it is considered indicative of intestinal and systemic inflammation. Further research is needed to develop targeted (poly)phenol-rich diets against age-related gut dysfunction and inflammation.Trial registration28/04/2017; ISRCTN10214981; https://doi.org/10.1186/ISRCTN10214981.

VEGF-A165a and angiopoietin-2 differently affect the barrier formed by retinal endothelial cells

Exposure to VEGF-A165a over several days leads to a persistent dysfunction of the very tight barrier formed by immortalized endothelial cells of the bovine retina (iBREC). Elevated permeability of the barrier is indicated by low cell index values determined by electric cell-substrate impedance measurements, by lower amounts of claudin-1, and by disruption of the homogenous and continuous staining of vascular endothelial cadherin at the plasma membrane. Because of findings that suggest modulation of VEGF-A's detrimental effects on the inner blood-retina barrier by the angiogenic growth factor angiopoietin-2, we investigated in more detail in vitro whether this growth factor indeed changes the stability of the barrier formed by retinal endothelial cells or modulates effects of VEGF-A. In view of the clinical relevance of anti-VEGF therapy, we also studied whether blocking VEGF-A-driven signaling is sufficient to prevent barrier dysfunction induced by a combination of both growth factors. Although angiopoietin-2 stimulated proliferation of iBREC, the formed barrier was not weakened at a concentration of 3 nM: Cell index values remained high and expression or subcellular localization of claudin-1 and vascular endothelial cadherin, respectively, were not affected. Angiopoietin-2 enhanced the changes induced by VEGF-A165a and this was more pronounced at lower concentrations of VEGF-A165a. Specific inhibition of the VEGF receptors with tivozanib as well as interfering with binding of VEGF-A to its receptors with bevacizumab prevented the detrimental effects of the growth factors; dual binding of angiopoietin-2 and VEGF-A by faricimab was marginally more efficient. Uptake of extracellular angiopoietin-2 by iBREC can be efficiently prevented by addition of faricimab which is also internalized by the cells. Exposure of the cells to faricimab over several days stabilized their barrier, confirming that inhibition of VEGF-A signaling is not harmful to this cell type. Taken together, our results confirm the dominant role of VEGF-A165a in processes resulting in increased permeability of retinal endothelial cells in which angiopoietin-2 might play a minor modulating role.

Glucose-Regulated Protein 78, via Releasing β-Catenin from Adherens Junctions, Facilitates Its Interaction with STAT3 in Mediating Retinal Neovascularization

Retinopathy due to neovascularization is one of the major causes of vision loss. To understand the mechanisms underlying retinal neovascularization the oxygen-induced retinopathy (OIR) model was used. Two-dimensional gel matrix-assisted laser desorption/ionization time-of-flight/time-of-flight analysis of normoxic and 24-hour post-OIR mice pups' retinas revealed that glucose-regulated protein 78 (GRP78) was one of the several molecules induced by OIR in the retinal endothelial cells (ECs). Vascular endothelial growth factor A (VEGFA) also induced GRP78 expression independent of endoplasmic reticulum stress response in human retinal microvascular endothelial cells, and its depletion reduced VEGFA-induced EC angiogenic responses. Consistent with these observations, EC-specific deletion of GRP78 inhibited OIR-induced retinal neovascularization. GRP78 bound with vascular endothelial-cadherin and released adherens junction, but not Wnt-mediated, β-catenin. β-catenin, in turn, via interacting with STAT3, triggered cyclin D1 expression. Furthermore, depletion of β-catenin or cyclin D1 levels negated VEGFA-induced EC angiogenic responses and OIR-induced retinal neovascularization. EC-specific deletion of GRP78 also suppressed OIR-induced vascular leakage. Studies of upstream signaling indicated that activating transcription factor 6 mediated GRP78 induction in the modulation of VEGFA-induced EC angiogenic responses and OIR-induced retinal neovascularization. Together, these observations revealed that GRP78, independent of its response to endoplasmic reticulum stress, is involved in mediating EC angiogenic responses by VEGFA and retinal neovascularization by OIR. In view of these findings, GRP78 emerges as a desirable target for drug development against diabetic retinopathy.

Reversal of pulmonary veno-occlusive disease phenotypes by inhibition of the integrated stress response.

Pulmonary veno-occlusive disease (PVOD) is a rare form of pulmonary hypertension arising from EIF2AK4 gene mutations or mitomycin C (MMC) administration. The lack of effective PVOD therapies is compounded by a limited understanding of the mechanisms driving vascular remodeling in PVOD. Here we show that administration of MMC in rats mediates activation of protein kinase R (PKR) and the integrated stress response (ISR), which leads to the release of the endothelial adhesion molecule vascular endothelial (VE) cadherin (VE-Cad) in complex with RAD51 to the circulation, disruption of endothelial barrier and vascular remodeling. Pharmacological inhibition of PKR or ISR attenuates VE-Cad depletion, elevation of vascular permeability and vascular remodeling instigated by MMC, suggesting potential clinical intervention for PVOD. Finally, the severity of PVOD phenotypes was increased by a heterozygous BMPR2 mutation that truncates the carboxyl tail of the receptor BMPR2, underscoring the role of deregulated bone morphogenetic protein signaling in the development of PVOD.

Molecular Mechanisms Underlying Loss of Vascular and Epithelial Integrity in Irritable Bowel Syndrome

The pathophysiology of irritable bowel syndrome (IBS) is multifactorial and includes epithelial barrier dysfunction, a key element at the interface between the gut lumen and the deeper intestinal layers. Beneath the epithelial barrier there is the vascular one representing the last barrier to avoid luminal antigen dissemination The aims of this study were to correlate morpho-functional aspects of epithelial and vascular barriers with symptom perception in IBS. Seventy-eight healthy subjects (controls) and 223 patients with IBS were enrolled in the study and phenotyped according to validated questionnaires. Sugar test was used to evaluate invivo permeability. Immunohistochemistry, western blot, and electron microscopy were used to characterize the vascular barrier. Vascular permeability was evaluated by assessing the mucosal expression of plasmalemma vesicle-associated protein-1 and vascular endothelial cadherin. Caco-2 or human umbilical vein endothelial cell monolayers were incubated with soluble mediators released by mucosal biopsies to highlight the mechanisms involved in permeability alteration. Correlation analyses have been performed among experimental and clinical data. The intestinal epithelial barrier was compromised in patients with IBS throughout the gastrointestinal tract. IBS-soluble mediators increased Caco-2 permeability via a downregulation of tight junction gene expression. Blood vessel density and vascular permeability were increased in the IBS colonic mucosa. IBS mucosal mediators increased permeability in human umbilical vein endothelial cell monolayers through the activation of protease-activated receptor-2 and histone deacetylase 11, resulting in vascular endothelial cadherin downregulation. Permeability changes correlated with intestinal and behavioral symptoms and health-related quality of life of patients with IBS. Epithelial and vascular barriers are compromised in patients with IBS and contribute to clinical manifestations.