Endothelial TRPV4 channel mediates the vasodilation induced by Tanshinone IIA.

Tanshinone IIA (TSA), the main lipo-soluble component from the dried rhizome of Salvia miltiorrhiza, has been shown to induce vasodilation. However, the underlying mechanisms remains unclear. This study aimed to investigate the effect of TSA on the vasodilation of small resistant arteries ex vivo. Vascular myography revealed that endothelial denudation reduced significantly the vasodilatory effect of TSA. Blocking transient receptor potential vanilloid 4 (TRPV4) channels prevented TSA-induced vasodilation. Whole-cell patch-clamp analysis revealed that the current passing through TRPV4 channels increased after TSA treatment in endothelial cells (ECs). This was attributed to reduced TRPV4 protein degradation along with its increased expression. The TRPV4 inhibitor HC-067047 lowed nitric oxide (NO) production and TSA-induced expression of endothelial nitric oxide synthase (eNOS). Moreover, it increased the production of cyclic guanosine monophosphate (cGMP) and protein kinase G (PKG). The present results indicate that TSA induces endothelium-dependent vasodilation, which is mediated by the TRPV4-NO-PKG signaling pathway. These findings highlight the potential of TSA, a compound known in traditional Chinese medicine as Danshen (Salvia miltiorrhiza), for future cardiovascular therapeutic strategies.

Shenfu Injection ameliorates endotoxemia-associated endothelial dysfunction and organ injury via inhibiting PI3K/Akt-mediated glycolysis.

ETHNOPHARMACOLOGICAL RELEVANCE: Microcirculatory dysfunction is one of the main characteristics of sepsis. Shenfu Injection (SFI) as a traditional Chinese medicine is widely applied in clinical severe conditions. Recent studies have shown that SFI has the ability to ameliorate sepsis-induced inflammation and to improve microcirculation perfusion. AIM OF THE STUDY: This study aims to investigate the underlying mechanism of SFI for ameliorating sepsis-associated endothelial dysfunction and organ injury. MATERIALS AND METHODS: Side-stream dark-field (SDF) imaging was used to monitor the sublingual microcirculation of septic patients treated with or without SFI. Septic mouse model was used to evaluate the effects of SFI in vivo. Metabolomics and transcriptomics were performed on endothelial cells to identify the underlying mechanism for SFI-related protective effect on endothelial cells. RESULTS: SFI effectively abolished the disturbance and loss of sublingual microcirculation in septic patients. Twenty septic shock patients with or without SFI administration were enrolled and the data showed that SFI significantly improved the levels of total vessel density (TVD), perfused vessel density (PVD), microvascular flow index (MFI), and the proportion of perfused vessels (PPV). The administration of SFI significantly decreased the elevated plasma levels of Angiopoietin-2 (Ang2) and Syndecan-1, which are biomarkers indicative of endothelial damage in sepsis patients. In the mouse septic model in vivo, SFI inhibited the upregulation of endothelial adhesion molecules and Ly6G+ neutrophil infiltration while restored the expression of VE-Cadherin in the vasculature of the lung, kidney, and liver tissue. Additionally, SFI reduced the plasma levels of Ang2, Monocyte Chemoattractant Protein-1(MCP1), and Interleukin-6 (IL6), and alleviated liver and kidney injury in septic mice. Moreover, SFI significantly inhibited the inflammatory activation and increased permeability of endothelial cells induced by endotoxins in vitro. By performing metabolomics and transcriptomics, we identified the activation of PI3K/Akt-mediated glycolysis as the underlying mechanism for SFI-related protective effect on endothelial cells. CONCLUSIONS: Our findings revealed that SFI may improve microcirculation perfusion and endothelial function in sepsis via inhibiting PI3K/Akt-mediated glycolysis, providing theoretical evidence for the clinical application of SFI.

Papillary endothelial hyperplasia (Masson's tumor) of the breast: A diagnostic challenge.

Papillary endothelial hyperplasia (PEH) or Masson's tumor is a rare benign vascular tumor that usually appears in the soft tissues of the head and neck, trunk and extremities, being extremely rare in the breast. Its diagnosis can be a challenge, especially in the follow-up of patients with previous disease of breast carcinoma. We present the case of a 65-year-old patient, with a history of bilateral breast cancer and reconstruction with implants, who presented a Masson's tumor during follow-up. An ultrasound scan was performed, showing a well-circumscribed mass in the left breast, located in the posterior contour of the implant. Subsequently, magnetic resonance imaging (MR) depicted an enhancing tumor, without infiltration of adjacent structures. Finally, the definitive anatomopathological diagnosis was obtained after surgical excision.

Perfusion and pulsatile pressure: their relationship with target organ damage in the African-PREDICT study.

BACKGROUND: Hypertension is the leading risk factor for subclinical target-organ damage (TOD) and cardiovascular disease (CVD). Little is known about the relationship between different pressure measures and subclinical TOD, especially in young populations. We compared the strength of associations of subclinical TOD markers with perfusion and pulsatile pressure in young adults. METHODS: A total of 1 187 young adults from the African-PREDICT study were included. Ambulatory mean arterial pressure (MAP) and pulse pressure (PP) was obtained. Markers of subclinical TOD were measured and included left ventricular mass index (LVMi), carotid intimamedia thickness (cIMT), carotidfemoral pulse wave velocity (cfPWV), central retinal arteriolar equivalent (CRAE) and albumin to creatinine ratio (ACR). RESULTS: Measures of sub-clinical TOD (cIMT, cfPWV and CRAE), associated stronger with perfusion pressure (all p < 0.001) than pulsatile pressure in unadjusted models. Stronger associations were found between cfPWV (adjusted R2 = 0.26), CRAE (adjusted R2 = 0.12) and perfusion pressure (all p ≤ 0.001) than pulsatile pressure independent of several non-modifiable and modifiable risk factors. CONCLUSIONS: In young, healthy adults, perfusion pressure is more strongly associated with subclinical TOD markers than pulsatile pressure. These findings contribute to the understanding of the development of early cardiovascular changes and may guide future intervention strategies.

HCC-1 Accelerates Atherosclerosis by Inducing Endothelial Cell and Macrophage Pyroptosis and Serves as an Early Diagnostic Biomarker.

BACKGROUND: HCC-1 (hemofiltrate CC chemokine-1), a CC-type chemokine, exerts function to change intracellular calcium concentration, induce leukocyte, and manipulate enzyme release especially in monocytes. It has been reported that HCC-1 could predict the persistent acute kidney injury or suppress hepatocellular carcinoma by modulating cell cycle and promoting apoptosis, while the effect of HCC-1 on atherosclerosis is poorly understood. Here, we aimed to clarify the function and mechanism of HCC-1 in atherosclerosis and whether it could serve as a novel biomarker for the diagnosis of atherosclerosis. METHODS: HCC-1 expression in serum, atherosclerotic plaques, and normal arterial tissue from patients with atherosclerosis and control group was assessed by ELISA, immunohistochemistry and confocal microscope, and bioinformatic analysis. The atherosclerotic model of HCC-1 overexpressing and control mice was generated by tail vein injection of adeno-associated virus serotype 9-HCC-1 on an ApoE-/- background. Cell adhesion, polarization, and pyroptosis were evaluated in vitro. The relationship between HCC-1 concentration in serum and atherosclerosis was analyzed in patients with atherosclerosis. RESULTS: HCC-1 expression was positively correlated with the occurrence and stable-unstable switch of atherosclerosis under bioinformatic analysis, which is further supported by the results of increased HCC-1 expression in AS patients both in serum and atherosclerotic plaque. adeno-associated virus serotype 9-HCC-1 mice had higher levels of inflammatory factors, increased macrophage accumulation and pyroptotic rate in plaque, and decreased atherosclerotic plaque stability. In vitro, HCC-1 promoted monocyte adhesion and M1 polarization and induced inflammation and pyroptosis both in ECs and macrophages. CONCLUSIONS: HCC-1 expression was increased in patients with atherosclerosis, and HCC-1 overexpression accelerated atherosclerotic burden via an enhancement in monocyte recruitment, M1 polarization, and pyroptosis both in ECs and macrophages. Our findings suggested that HCC-1 may serve as an early biomarker for the diagnosis of atherosclerosis, with the capacity to reflect the degree of stenosis.

GPR126 is a specifier of blood-brain barrier formation in the mouse central nervous system.

The blood-brain barrier (BBB) acquires unique properties to regulate neuronal function during development. The formation of the BBB, which occurs in tandem with angiogenesis, is directed by the Wnt/ß-catenin signaling pathway. Yet the exact molecular interplay remains elusive. Our study reveals the G protein-coupled receptor GPR126 as a critical target of canonical Wnt signaling, essential for the development of the BBB's distinctive vascular characteristics and its functional integrity. Endothelial cell-specific deletion of the Gpr126 gene in mice induced aberrant vascular morphogenesis, resulting in disrupted BBB organization. Simultaneously, heightened transcytosis in vitro compromised barrier integrity, resulting in enhanced vascular permeability. Mechanistically, GPR126 enhanced endothelial cell migration, pivotal for angiogenesis, acting through an interaction between LRP1 and ß1 integrin, thereby balancing the levels of ß1 integrin activation and recycling. Overall, we identified GPR126 as a specifier of an organotypic vascular structure, which sustained angiogenesis and guaranteed the acquisition of the BBB properties during development.

Polystyrene Microplastics Induce Injury to the Vascular Endothelial Through NLRP3-Mediated Pyroptosis.

The health risks associated with microplastics have attracted widespread attention. Polystyrene microplastics (PS-MPs) can induce damage to cardiac tissue, while pyroptosis-mediated injury to the vascular endothelial plays a vital role in the pathogenesis of cardiovascular diseases. The study intended to explore the role and mechanism of NLR family pyrin domain containing 3 (NLRP3) mediated pyroptosis in PS-MPs causing the injury of vascular endothelial cells. In vivo, Wistar rats were exposed to 0.5, 5, and 50 mg/kg/d 0.5 µm PS-MPs. In vitro, the human vascular endothelial cells (HUVECs) were used for mechanistic studies. siRNA was used for silencing the NILRP3 gene. H&E staining and flow cytometry were performed to examine the vascular injury and cell membrane damage. The oxidative stress was detected by flow cytometry, immunofluorescence, and corresponding kits. ELISA were used to measure the levels of inflammatory factors. Real-time PCR and western blot were used to measure the expression of pyroptosis signaling pathway. In rats, PS-MPs could cause vascular damage, oxidative stress, and inflammatory response, and activated the pyroptosis signaling pathway. HUVECs exposure to PS-MPs, the vitality decreased in a dose-dependent manner, ROS and MDA were significantly increased while SOD was decreased. PS-MPs induced the onset of pyroptosis signaling pathway in HUVECs. Cell membrane damage and the levels of IL-Iß and IL-18 in HUVECs significantly increased, those are symbols for the development of pyroptosis. Inhibition of NLRP3-mediated pyroptosis effectively protected HUVECs from PS-MPs-induced damage. Pyroptosis played a vital role in controlling the vascular endothelial injury caused by PS-MPs.

Excess cardiovascular mortality in men with non-alcoholic fatty liver disease: A cause for concern!

Non-alcoholic fatty liver disease (NAFLD) has emerged as the commonest cause of chronic liver disease worldwide in recent years. With time, our understanding of NAFLD has evolved from an isolated liver condition to a systemic disease with significant manifestations beyond the liver. Amongst them, cardiovascular diseases (CVDs) are the most important and clinically relevant. Recent research supports a strong independent link between NALFD and CVD beyond the shared risk factors and pathophysiology. Female sex hormones are well known to not only protect against CVD in pre-menopausal females, but also contribute to improved adipose tissue function and preventing its systemic deposition. Recent research highlights the increased risk of major adverse cardiovascular-cerebral events (MACCE) amongst male with NAFLD compared to females. Further, racial variation was observed in MACCE outcomes in NAFLD, with excess mortality in the Native Americans and Asian Pacific Islanders compared to the other races.

Circulating extracellular microvesicles associated with electronic cigarette use increase endothelial cell inflammation and reduce nitric oxide production.

The purpose of this study was to determine the effect of circulating microvesicles isolated from chronic electronic (e-)cigarette users on cultured human umbilical vein endothelial cell (HUVEC) expression of nuclear factor-κB (NF-κB), cellular cytokine release, phosphorylation of endothelial nitric oxide synthase (eNOS) and NO production. The HUVECs were treated with microvesicles isolated via flow cytometry from nine non-tobacco users (five male and four female; 22 ± 2 years of age) and 10 e-cigarette users (six male and four female; 22 ± 2 years of age). Microvesicles from e-cigarette users induced significantly greater release of interleukin-6 (183.4 ± 23.6 vs. 150.6 ± 15.4 pg/mL; P = 0.002) and interleukin-8 (160.0 ± 31.6 vs. 129.4 ± 11.2 pg/mL; P = 0.01), in addition to expression of p-NF-κB p65 (Ser536) (18.8 ± 3.4 vs. 15.6 ± 1.5 a.u.; P = 0.02) from HUVECs compared with microvesicles from non-tobacco users. Nuclear factor-κB p65 was not significantly different between microvesicles from the non-tobacco users and from the e-cigarette users (87.6 ± 8.7 vs. 90.4 ± 24.6 a.u.; P = 0.701). Neither total eNOS (71.4 ± 21.8 vs. 80.4 ± 24.5 a.u.; P = 0.413) nor p-eNOS (Thr495) (229.2 ± 26.5 vs. 222.1 ± 22.7 a.u.; P = 0.542) was significantly different between microvesicle-treated HUVECs from non-tobacco users and e-cigarette users. However, p-eNOS (Ser1177) (28.9 ± 6.2 vs. 45.8 ± 9.0 a.u.; P < 0.001) expression was significantly lower from e-cigarette users compared with non-tobacco users. Nitric oxide production was significantly lower (8.2 ± 0.6 vs. 9.7 ± 0.9 µmol/L; P = 0.001) in HUVECs treated with microvesicles from e-cigarette users compared with microvesicles from non-tobacco users. This study demonstrated increased NF-κB activation and inflammatory cytokine production, in addition to diminished eNOS activity and NO production resulting from e-cigarette use. HIGHLIGHTS: What is the central question of this study? Circulating microvesicles contribute to cardiovascular health and disease via their effects on the vascular endothelium. The impact of electronic (e-)cigarette use on circulating microvesicle phenotype is not well understood. What is the main finding and its importance? Circulating microvesicles from e-cigarette users increase endothelial cell inflammation and impair endothelial nitric oxide production. Endothelial inflammation and diminished nitric oxide bioavailability are central factors underlying endothelial dysfunction and, in turn, cardiovascular disease risk. Deleterious changes in the functional phenotype of circulating microvesicles might contribute to the reported adverse effects of e-cigarette use on cardiovascular health.

Contribution of the Arterial Cells to Atherosclerosis and Plaque Formation.

Atherosclerosis is commonly known as an inflammatory disease that is characterized by lipid deposition in the arterial wall, causing gradual restriction or complete blockade of blood flow, which can cause complications such as myocardial infarction, stroke, or peripheral artery disease. Several factors contribute to initiation and progression of atherosclerotic plaque formation. The role of macrophages and leukocytes in atherosclerosis have been well explored. Here, we provide an overview of what has been reported on the role and impact of the arterial cells on plaque formation, and vice versa. The atherogenic environment can trigger transformation and dedifferentiation of the endothelial cells, smooth muscle cells, and fibroblasts whereby they can either directly contribute to plaque formation, or influence its composition. Recent studies have demonstrated the plasticity in the identity of the arterial cells, formation of intermediate cell types that share the characteristics of multiple cell types, and have revealed novel roles and functions for these cells in atherosclerosis. The potential for all vascular cells to cross-transdifferentiate, and detection of cells with mosaic characteristics in the atherosclerotic plaques reveal that the plaque environment is a complex and dynamic environment that could regulate the disease progression independent from the circulating lipid levels. We will also provide an overview on the interplay between sex and atherosclerosis, which has remained an underexplored area.

Regulatory mechanism of DDX5 in ox-LDL-induced endothelial cell injury through the miR-640/SOX6 axis.

BACKGROUND: Endothelial dysfunction is an early and pre-clinical manifestation of coronary heart disease (CHD). OBJECTIVE: This study investigates the role of DDX5 in oxidized low-density lipoprotein (ox-LDL)-induced endothelial cell injury to confer novel targets for the treatment of CHD. METHODS: Endothelial cells were induced by ox-LDL. DDX5, pri-miR-640, pre-miR-640, miR-640, and SOX6 expressions were analyzed by RT-qPCR and Western blot. DDX5 expression was intervened by shRNA, followed by CCK-8 analysis of proliferation, flow cytometry detection of apoptosis, and tube formation assay analysis of angiogenic potential of cells. The binding between DDX5 and pri-miR-640 was determined by RIP, and the pri-miR-640 RNA stability was measured after actinomycin D treatment. Dual-luciferase assay verified the targeting relationship between miR-640 and SOX6. RESULTS: DDX5 and miR-640 were highly expressed while SOX6 was poorly expressed in ox-LDL-induced endothelial cells. Silence of DDX5 augmented cell proliferation, abated apoptosis, and facilitated angiogenesis. Mechanistically, RNA binding protein DDX5 elevated miR-640 expression by weakening the degradation of pri-miR-640, thereby reducing SOX6 expression. Combined experimental results indicated that overexpression of miR-640 or low expression of SOX6 offset the protective effect of DDX5 silencing on cell injury. CONCLUSION: DDX5 elevates miR-640 expression by repressing the degradation of pri-miR-640 and then reduces SOX6 expression, thus exacerbating ox-LDL-induced endothelial cell injury.

Depletion of Activated Hepatic Stellate Cells and Capillarized Liver Sinusoidal Endothelial Cells Using a Rationally Designed Protein for Nonalcoholic Steatohepatitis and Alcoholic Hepatitis Treatment.

Nonalcoholic steatohepatitis (NASH) and alcoholic hepatitis (AH) affect a large part of the general population worldwide. Dysregulation of lipid metabolism and alcohol toxicity drive disease progression by the activation of hepatic stellate cells and the capillarization of liver sinusoidal endothelial cells. Collagen deposition, along with sinusoidal remodeling, alters sinusoid structure, resulting in hepatic inflammation, portal hypertension, liver failure, and other complications. Efforts were made to develop treatments for NASH and AH. However, the success of such treatments is limited and unpredictable. We report a strategy for NASH and AH treatment involving the induction of integrin αvß3-mediated cell apoptosis using a rationally designed protein (ProAgio). Integrin αvß3 is highly expressed in activated hepatic stellate cells (αHSCs), the angiogenic endothelium, and capillarized liver sinusoidal endothelial cells (caLSECs). ProAgio induces the apoptosis of these disease-driving cells, therefore decreasing collagen fibril, reversing sinusoid remodeling, and reducing immune cell infiltration. The reversal of sinusoid remodeling reduces the expression of leukocyte adhesion molecules on LSECs, thus decreasing leukocyte infiltration/activation in the diseased liver. Our studies present a novel and effective approach for NASH and AH treatment.

Pulmonary Vascular Responses to Chronic Intermittent Hypoxia in a Guinea Pig Model of Obstructive Sleep Apnea.

Experimental evidence suggests that chronic intermittent hypoxia (CIH), a major hallmark of obstructive sleep apnea (OSA), boosts carotid body (CB) responsiveness, thereby causing increased sympathetic activity, arterial and pulmonary hypertension, and cardiovascular disease. An enhanced circulatory chemoreflex, oxidative stress, and NO signaling appear to play important roles in these responses to CIH in rodents. Since the guinea pig has a hypofunctional CB (i.e., it is a natural CB knockout), in this study we used it as a model to investigate the CB dependence of the effects of CIH on pulmonary vascular responses, including those mediated by NO, by comparing them with those previously described in the rat. We have analyzed pulmonary artery pressure (PAP), the hypoxic pulmonary vasoconstriction (HPV) response, endothelial function both in vivo and in vitro, and vascular remodeling (intima-media thickness, collagen fiber content, and vessel lumen area). We demonstrate that 30 days of the exposure of guinea pigs to CIH (FiO2, 5% for 40 s, 30 cycles/h) induces pulmonary artery remodeling but does not alter endothelial function or the contractile response to phenylephrine (PE) in these arteries. In contrast, CIH exposure increased the systemic arterial pressure and enhanced the contractile response to PE while decreasing endothelium-dependent vasorelaxation to carbachol in the aorta without causing its remodeling. We conclude that since all of these effects are independent of CB sensitization, there must be other oxygen sensors, beyond the CB, with the capacity to alter the autonomic control of the heart and vascular function and structure in CIH.

Cell-Electrode Models for Impedance Analysis of Epithelial and Endothelial Monolayers Cultured on Microelectrodes.

Electric cell-substrate impedance sensing has been used to measure transepithelial and transendothelial impedances of cultured cell layers and extract cell parameters such as junctional resistance, cell-substrate separation, and membrane capacitance. Previously, a three-path cell-electrode model comprising two transcellular pathways and one paracellular pathway was developed for the impedance analysis of MDCK cells. By ignoring the resistances of the lateral intercellular spaces, we develop a simplified three-path model for the impedance analysis of epithelial cells and solve the model equations in a closed form. The calculated impedance values obtained from this simplified cell-electrode model at frequencies ranging from 31.25 Hz to 100 kHz agree well with the experimental data obtained from MDCK and OVCA429 cells. We also describe how the change in each model-fitting parameter influences the electrical impedance spectra of MDCK cell layers. By assuming that the junctional resistance is much smaller than the specific impedance through the lateral cell membrane, the simplified three-path model reduces to a two-path model, which can be used for the impedance analysis of endothelial cells and other disk-shaped cells with low junctional resistances. The measured impedance spectra of HUVEC and HaCaT cell monolayers nearly coincide with the impedance data calculated from the two-path model.

Quercetin ameliorates atherosclerosis by inhibiting inflammation of vascular endothelial cells via Piezo1 channels.

BACKGROUND: Natural antioxidants, exemplified by quercetin (Qu), have been shown to exert a protective effect against atherosclerosis (AS). However, the precise pharmacological mechanisms of Qu also remain elusive. PURPOSE: Here, we aimed to uncover the anti-atherosclerotic mechanisms of Qu. METHODS/STUDY DESIGNS: The inflammatory cytokine expression, activity of NLRP3 inflammasome and NF-κB, as well as mechanically activated currents and intracellular calcium levels were measured in endothelial cells (ECs). In addition, to explore whether Qu inhibited atherosclerotic plaque formation via Piezo1 channels, Ldlr-/- and Piezo1 endothelial-specific knockout mice (Piezo1△EC) were established. RESULTS: Our findings revealed that Qu significantly inhibited Yoda1-evoked calcium response in human umbilical vein endothelial cells (HUVECs), underscoring its role as a selective modulator of Piezo1 channels. Additionally, Qu effectively reduced mechanically activated currents in HUVECs. Moreover, Qu exhibited a substantial inhibitory effect on inflammatory cytokine expression and reduced the activity of NF-κB/NLRP3 in ECs exposed to ox-LDL or mechanical stretch, and these effects remained unaffected after Piezo1 genetic depletion. Furthermore, our study demonstrated that Qu substantially reduced the formation of atherosclerotic plaques, and this effect remained consistent even after Piezo1 genetic depletion. CONCLUSION: These results collectively provide compelling evidence that Qu ameliorates atherosclerosis by inhibiting the inflammatory response in ECs by targeting Piezo1 channels. In addition, Qu modulated atherosclerosis via inhibiting Piezo1 mediated NFκB/IL-1ß and NLRP3/caspase1/ IL-1ß axis to suppress the inflammation. Overall, this study reveals the potential mechanisms by which natural antioxidants, such as Qu, protect against atherosclerosis.

NAD+ overconsumption by poly (ADP-ribose) polymerase (PARP) under oxidative stress induces cytoskeletal disruption in vascular endothelial cell.

Vascular endothelial cytoskeletal disruption leads to increased vascular permeability and is involved in the pathogenesis and progression of various diseases. Oxidative stress can increase vascular permeability by weakening endothelial cell-to-cell junctions and decrease intracellular nicotinamide adenine dinucleotide (NAD+) levels. However, it remains unclear how intracellular NAD+ variations caused by oxidative stress alter the vascular endothelial cytoskeletal organization. In this study, we demonstrated that oxidative stress activates poly (ADP-ribose [ADPr]) polymerase (PARP), which consume large amounts of intracellular NAD+, leading to cytoskeletal disruption in vascular endothelial cells. We found that hydrogen peroxide (H2O2) could transiently disrupt the cytoskeleton and reduce intracellular total NAD levels in human umbilical vein endothelial cells (HUVECs). H2O2 stimulation led to rapid increase in ADPr protein levels in HUVECs. Pharmaceutical PARP inhibition counteracted H2O2-induced total NAD depletion and cytoskeletal disruption, suggesting that NAD+ consumption by PARP induced cytoskeletal disruption. Additionally, supplementation with nicotinamide mononucleotide (NMN), the NAD+ precursor, prevented both intracellular total NAD depletion and cytoskeletal disruption induced by H2O2 in HUVECs. Inhibition of the NAD+ salvage pathway by FK866, a nicotinamide phosphoribosyltransferase inhibitor, maintained H2O2-induced cytoskeletal disruption, suggesting that intracellular NAD+ plays a crucial role in recovery from cytoskeletal disruption. Our findings provide further insights into the potential application of PARP inhibition and NMN supplementation for the treatment and prevention of diseases involving vascular hyperpermeability.

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

BACKGROUND AND AIMS: The pathophysiology of irritable bowel syndrome (IBS) is multifactorial and included 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. METHODS: Seventy-eight healthy subjects (controls) and 223 IBS patients were enrolled in the study and phenotyped according to validated questionnaires. Sugar test was used to evaluate in vivo 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 (VEC). Caco-2 or HUVEC 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. RESULTS: Intestinal epithelial barrier was compromised in IBS patients 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 HUVEC monolayers through the activation of protease-activated receptor (PAR)-2 and histone deacetylase (HDAC)11, resulting in VEC downregulation. Permeability changes correlated with intestinal and behavioral symptoms and health-related quality of life of IBS patients. CONCLUSION: Epithelial and vascular barriers are compromised in IBS patients and contribute to clinical manifestations.

Thrombotic Microangiopathies and the Kidney.

Thrombotic microangiopathy (TMA) is a pathological lesion that occurs due to endothelial injury. It can be seen in a heterogenous group of disorders, typically characterized by microangiopathic hemolytic anemia, thrombocytopenia, and end-organ ischemia. TMA can also be renal limited with no systemic manifestations. There are multiple etiologies of a TMA with complement activation being a core underlying mechanism, although the nature and extent of complement involvement can vary. A further complicated factor is the cross talk between complement, neutrophils, and coagulation pathways in the pathophysiology of TMAs. Therefore, a thorough and systematic clinical history and laboratory evaluation are critical to establish the cause and pathophysiology of a TMA. Furthermore, TMAs are associated with significant morbidity and mortality, and timely diagnosis is key for appropriate management and to prevent end-stage kidney disease and other associated complications. In this review, we focus on the pathology, mechanisms, diagnostic work up and treatment of TMAs associated with various etiologies. We also define the complement evaluations that should be conducted in these patients and further highlight the currently approved complement therapies as well as others in the pipeline.

Are Altered Expression of Vascular Endothelial Growth Factor and Placental Growth Factor Associated with Placental Angiogenesis in Recurrent Pregnancy Loss?

Angiogenesis is one of the most important steps during pregnancy for placental and fetal development. Based on the hypothesis that vascular insufficiency and altered angiogenesis may lead to early pregnancy loss, the present study was aimed to understand the role of Vascular endothelial growth factor (VEGFA) and Placental growth factor (PLGF) gene expression in placental angiogenesis in the pathogenesis of Recurrent pregnancy loss (RPL). Gene expression analysis of VEGFA and PLGF was carried out in the placental tissue collected from 30 women with recurrent pregnancy loss and compared with the placenta obtained from 16 women with medically terminated pregnancy. The mRNA expression of both VEGFA and PLGF genes were significantly downregulated in the placenta of recurrent pregnancy loss in comparison to the placenta of medically terminated pregnancies. In conclusion the results of the present study suggest that altered expression of VEGFA and PLGF genes in placenta disturb the angiogenesis and contribute to the pathogenesis of recurrent pregnancy loss.

Silencing of transient receptor potential canonical channel 4 inhibits endothelial progenitor cell angiogenesis by suppressing VEGF and SDF-1.

OBJECTIVES: Endothelial progenitor cells (EPCs) play a crucial role in acquired angiogenesis and endothelial injury repair. Transient receptor potential canonical channel 4 (TRPC4), a key component of store-operated calcium channels, is essential for EPC function. While the role of TRPCs has been clarified in vascular diseases, the relationship between TRPC4 and EPC function, along with the underlying molecular mechanisms, remains unclear and requires further elucidation. METHODS: EPCs were isolated from canine bone marrow and identified by morphology and flow cytometry. TRPC4 was transfected into EPCs using lentivirus or negative control, and its expression was assessed using real-time polymerase chain reaction (RT-PCR). Proliferation, migration, and tube formation were evaluated using Cell Counting Kit-8 (CCK-8), Transwell, and Matrigel assays, respectively. Levels of vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1 (SDF-1) were measured using enzyme-linked immunosorbent assay (ELISA). RESULTS: TRPC4 mRNA expression was significantly reduced in TRPC4-short hairpin RNA (shRNA) transfected EPCs compared to the normal control (NC)-shRNA groups. Migration and tube formation were significantly decreased after TRPC4 silencing, while proliferation showed no difference. Additionally, levels of SDF-1 and VEGF in EPCs were markedly reduced following TRPC4 silencing. CONCLUSION: TRPC4 plays a crucial role in regulating angiogenesis in EPCs. Silencing of TRPC4 can lead to decreased angiogenesis by inhibiting VEGF and SDF-1 expression, suggesting that TRPC4 knockdown might be a novel therapeutic strategy for vascular diseases.