Acod1/itaconate activates Nrf2 in pulmonary microvascular endothelial cells to protect against the obesity-induced pulmonary microvascular endotheliopathy.

BACKGROUND: Obesity is the main risk factor leading to the development of various respiratory diseases, such as asthma and pulmonary hypertension. Pulmonary microvascular endothelial cells (PMVECs) play a significant role in the development of lung diseases. Aconitate decarboxylase 1 (Acod1) mediates the production of itaconate, and Acod1/itaconate axis has been reported to play a protective role in multiple diseases. However, the roles of Acod1/itaconate axis in the PMVECs of obese mice are still unclear. METHODS: mRNA-seq was performed to identify the differentially expressed genes (DEGs) between high-fat diet (HFD)-induced PMVECs and chow-fed PMVECs in mice (|log2 fold change| ≥ 1, p ≤ 0.05). Free fatty acid (FFA) was used to induce cell injury, inflammation and mitochondrial oxidative stress in mouse PMVECs after transfection with the Acod1 overexpressed plasmid or 4-Octyl Itaconate (4-OI) administration. In addition, we investigated whether the nuclear factor erythroid 2-like 2 (Nrf2) pathway was involved in the effects of Acod1/itaconate in FFA-induced PMVECs. RESULTS: Down-regulated Acod1 was identified in HFD mouse PMVECs by mRNA-seq. Acod1 expression was also reduced in FFA-treated PMVECs. Acod1 overexpression inhibited cell injury, inflammation and mitochondrial oxidative stress induced by FFA in mouse PMVECs. 4-OI administration showed the consistent results in FFA-treated mouse PMVECs. Moreover, silencing Nrf2 reversed the effects of Acod1 overexpression and 4-OI administration in FFA-treated PMVECs, indicating that Nrf2 activation was required for the protective effects of Acod1/itaconate. CONCLUSION: Our results demonstrated that Acod1/Itaconate axis might protect mouse PMVECs from FFA-induced injury, inflammation and mitochondrial oxidative stress via activating Nrf2 pathway. It was meaningful for the treatment of obesity-caused pulmonary microvascular endotheliopathy.

Vascular development, remodeling and maturation.

The development of the vascular system is crucial in supporting the growth and health of all other organs in the body, and vascular system dysfunction is the major cause of human morbidity and mortality. This chapter discusses three successive processes that govern vascular system development, starting with the differentiation of the primitive vascular system in early embryonic development, followed by its remodeling into a functional circulatory system composed of arteries and veins, and its final maturation and acquisition of an organ specific semi-permeable barrier that controls nutrient uptake into tissues and hence controls organ physiology. Along these steps, endothelial cells forming the inner lining of all blood vessels acquire extensive heterogeneity in terms of gene expression patterns and function, that we are only beginning to understand. These advances contribute to overall knowledge of vascular biology and are predicted to unlock the unprecedented therapeutic potential of the endothelium as an avenue for treatment of diseases associated with dysfunctional vasculature.

Doxycycline protects against sepsis-induced endothelial glycocalyx shedding.

Endothelial glycocalyx (eGC) covers the inner surface of the vessels and plays a role in vascular homeostasis. Syndecan is considered the "backbone" of this structure. Several studies have shown eGC shedding in sepsis and its involvement in organ dysfunction. Matrix metalloproteinases (MMP) contribute to eGC shedding through their ability for syndecan-1 cleavage. This study aimed to investigate if doxycycline, a potent MMP inhibitor, could protect against eGC shedding in lipopolysaccharide (LPS)-induced sepsis and if it could interrupt the vascular hyperpermeability, neutrophil transmigration, and microvascular impairment. Rats that received pretreatment with doxycycline before LPS displayed ultrastructural preservation of the eGC observed using transmission electronic microscopy of the lung and heart. In addition, these animals exhibited lower serum syndecan-1 levels, a biomarker of eGC injury, and lower perfused boundary region (PBR) in the mesenteric video capillaroscopy, which is inversely related to the eGC thickness compared with rats that only received LPS. Furthermore, this study revealed that doxycycline decreased sepsis-related vascular hyperpermeability in the lung and heart, reduced neutrophil transmigration in the peritoneal lavage and inside the lungs, and improved some microvascular parameters. These findings suggest that doxycycline protects against LPS-induced eGC shedding, and it could reduce vascular hyperpermeability, neutrophils transmigration, and microvascular impairment.

Aging-regulated PNUTS maintains endothelial barrier function via SEMA3B suppression.

Age-related diseases pose great challenges to health care systems worldwide. During aging, endothelial senescence increases the risk for cardiovascular disease. Recently, it was described that Phosphatase 1 Nuclear Targeting Subunit (PNUTS) has a central role in cardiomyocyte aging and homeostasis. Here, we determine the role of PNUTS in endothelial cell aging. We confirm that PNUTS is repressed in senescent endothelial cells (ECs). Moreover, PNUTS silencing elicits several of the hallmarks of endothelial aging: senescence, reduced angiogenesis and loss of barrier function. Findings are validate in vivo using endothelial-specific inducible PNUTS-deficient mice (Cdh5-CreERT2;PNUTSfl/fl), termed PNUTSEC-KO. Two weeks after PNUTS deletion, PNUTSEC-KO mice present severe multiorgan failure and vascular leakage. Transcriptomic analysis of PNUTS-silenced HUVECs and lungs of PNUTSEC-KO mice reveal that the PNUTS-PP1 axis tightly regulates the expression of semaphorin 3B (SEMA3B). Indeed, silencing of SEMA3B completely restores barrier function after PNUTS loss-of-function. These results reveal a pivotal role for PNUTS in endothelial homeostasis through a SEMA3B downstream pathway that provides a potential target against the effects of aging in ECs.

Hypersensitive blood vessels in Clarkson disease.

Idiopathic systemic capillary leak syndrome (ISCLS) is a rare, recurrent condition with dramatically increased blood vessel permeability and, therefore, induction of systemic edema, which may lead to organ damage and death. In this issue of the JCI, Ablooglu et al. showed that ISCLS vessels were hypersensitive to agents known to increase vascular permeability, using human biopsies, cell culture, and mouse models. Several endothelium-specific proteins that regulate endothelial junctions were dysregulated and thereby compromised the vascular barrier. These findings suggest that endothelium-intrinsic dysregulation underlies hyperpermeability and implicate the cytoplasmic serine/threonine protein phosphatase 2A (PP2A) as a potential drug target for the treatment of ISCLS.

Inflammatory risk contributes to post-COVID endothelial dysfunction through anti-ACKR1 autoantibody.

Subclinical vascular impairment can be exacerbated in individuals who experience sustained inflammation after COVID-19 infection. Our study explores the prevalence and impact of autoantibodies on vascular dysfunction in healthy COVID-19 survivors, an area that remains inadequately investigated. Focusing on autoantibodies against the atypical chemokine receptor 1 (ACKR1), COVID-19 survivors demonstrated significantly elevated anti-ACKR1 autoantibodies, correlating with systemic cytokines, circulating damaged endothelial cells, and endothelial dysfunction. An independent cohort linked these autoantibodies to increased vascular disease outcomes during a median 6.7-yr follow-up. We analyzed a single-cell transcriptome atlas of endothelial cells from diverse mouse tissues, identifying enriched Ackr1 expressions in venous regions of the brain and soleus muscle vasculatures, which holds intriguing implications for tissue-specific venous thromboembolism manifestations reported in COVID-19. Functionally, purified immunoglobulin G (IgG) extracted from patient plasma did not trigger cell apoptosis or increase barrier permeability in human vein endothelial cells. Instead, plasma IgG enhanced antibody-dependent cellular cytotoxicity mediated by patient PBMCs, a phenomenon alleviated by blocking peptide or liposome ACKR1 recombinant protein. The blocking peptide uncovered that purified IgG from COVID-19 survivors possessed potential epitopes in the N-terminal extracellular domain of ACKR1, which effectively averted antibody-dependent cellular cytotoxicity. Our findings offer insights into therapeutic development to mitigate autoantibody reactivity in blood vessels in chronic inflammation.

Translational Research of the Acute Effects of Negative Emotions on Vascular Endothelial Health: Findings From a Randomized Controlled Study.

BACKGROUND: Provoked anger is associated with an increased risk of cardiovascular disease events. The underlying mechanism linking provoked anger as well as other core negative emotions including anxiety and sadness to cardiovascular disease remain unknown. The study objective was to examine the acute effects of provoked anger, and secondarily, anxiety and sadness on endothelial cell health. METHODS AND RESULTS: Apparently healthy adult participants (n=280) were randomized to an 8-minute anger recall task, a depressed mood recall task, an anxiety recall task, or an emotionally neutral condition. Pre-/post-assessments of endothelial health including endothelium-dependent vasodilation (reactive hyperemia index), circulating endothelial cell-derived microparticles (CD62E+, CD31+/CD42-, and CD31+/Annexin V+) and circulating bone marrow-derived endothelial progenitor cells (CD34+/CD133+/kinase insert domain receptor+ endothelial progenitor cells and CD34+/kinase insert domain receptor+ endothelial progenitor cells) were measured. There was a group×time interaction for the anger versus neutral condition on the change in reactive hyperemia index score from baseline to 40 minutes (P=0.007) with a mean±SD change in reactive hyperemia index score of 0.20±0.67 and 0.50±0.60 in the anger and neutral conditions, respectively. For the change in reactive hyperemia index score, the anxiety versus neutral condition group by time interaction approached but did not reach statistical significance (P=0.054), and the sadness versus neutral condition group by time interaction was not statistically significant (P=0.160). There were no consistent statistically significant group×time interactions for the anger, anxiety, and sadness versus neutral condition on endothelial cell-derived microparticles and endothelial progenitor cells from baseline to 40 minutes. CONCLUSIONS: In this randomized controlled experimental study, a brief provocation of anger adversely affected endothelial cell health by impairing endothelium-dependent vasodilation.

Ion channel Piezo1 activation aggravates the endothelial dysfunction under a high glucose environment.

BACKGROUND: Vasculopathy is the most common complication of diabetes. Endothelial cells located in the innermost layer of blood vessels are constantly affected by blood flow or vascular components; thus, their mechanosensitivity plays an important role in mediating vascular regulation. Endothelial damage, one of the main causes of hyperglycemic vascular complications, has been extensively studied. However, the role of mechanosensitive signaling in hyperglycemic endothelial damage remains unclear. METHODS: Vascular endothelial-specific Piezo1 knockout mice were generated to investigate the effects of Piezo1 on Streptozotocin-induced hyperglycemia and vascular endothelial injury. In vitro activation or knockdown of Piezo1 was performed to evaluate the effects on the proliferation, migration, and tubular function of human umbilical vein endothelial cells in high glucose. Reactive oxygen species production, mitochondrial membrane potential alternations, and oxidative stress-related products were used to assess the extent of oxidative stress damage caused by Piezo1 activation. RESULTS: Our study found that in VECreERT2;Piezo1flox/flox mice with Piezo1 conditional knockout in vascular endothelial cells, Piezo1 deficiency alleviated streptozotocin-induced hyperglycemia with reduced apoptosis and abscission of thoracic aortic endothelial cells, and decreased the inflammatory response of aortic tissue caused by high glucose. Moreover, the knockout of Piezo1 showed a thinner thoracic aortic wall, reduced tunica media damage, and increased endothelial nitric oxide synthase expression in transgenic mice, indicating the relief of endothelial damage caused by hyperglycemia. We also showed that Piezo1 activation aggravated oxidative stress injury and resulted in severe dysfunction through the Ca2+-induced CaMKII-Nrf2 axis in human umbilical vein endothelial cells. In Piezo1 conditional knockout mice, Piezo1 deficiency partially restored superoxide dismutase activity and reduced malondialdehyde content in the thoracic aorta. Mechanistically, Piezo1 deficiency decreased CaMKII phosphorylation and restored the expression of Nrf2 and its downstream molecules HO-1 and NQO1. CONCLUSION: In summary, our study revealed that Piezo1 is involved in high glucose-induced oxidative stress injury and aggravated endothelial dysfunction, which have great significance for alleviating endothelial damage caused by hyperglycemia.

The impact of temperature on vascular function in connection with vascular laser treatment.

Pulsed dye lasers are used effectively in the treatment of psoriasis with long remission time and limited side effects. It is, however, not completely understood which biological processes underlie its favorable outcome. Pulsed dye laser treatment at 585-595 nm targets hemoglobin in the blood, inducing local hyperthermia in surrounding blood vessels and adjacent tissues. While the impact of destructive temperatures on blood vessels has been well studied, the effects of lower temperatures on the function of several cell types within the blood vessel wall and its periphery are not known. The aim of our study is to assess the functionality of isolated blood vessels after exposure to moderate hyperthermia (45 to 60°C) by evaluating the function of endothelial cells, smooth muscle cells, and vascular nerves. We measured blood vessel functionality of rat mesenteric arteries (n=19) by measuring vascular contraction and relaxation before and after heating vessels in a wire myograph. To this end, we elicited vascular contraction by addition of either high potassium solution or the thromboxane analogue U46619 to stimulate smooth muscle cells, and electrical field stimulation (EFS) to stimulate nerves. For measurement of endothelium-dependent relaxation, we used methacholine. Each vessel was exposed to one temperature in the range of 45-60°C for 30 seconds and a relative change in functional response after hyperthermia was determined by comparison with the response per stimulus before heating. Non-linear regression was used to fit our dataset to obtain the temperature needed to reduce blood vessel function by 50% (Half maximal effective temperature, ET50). Our findings demonstrate a substantial decrease in relative functional response for all three cell types following exposure to 55°C-60°C. There was no significant difference between the ET50 values of the different cell types, which was between 55.9°C and 56.9°C (P>0.05). Our data show that blood vessel functionality decreases significantly when exposed to temperatures between 55°C-60°C for 30 seconds. The results show functionality of endothelial cells, smooth muscle cells, and vascular nerves is similarly impaired. These results help to understand the biological effects of hyperthermia and may aid in tailoring laser and light strategies for selective photothermolysis that contribute to disease modification of psoriasis after pulsed dye laser treatment.

Vascular Response of Triiodothyronine on Isolated Aortic Rings: Contribution of Redox Mechanisms. / Resposta Vascular da Triiodotironina sobre Anéis de Aortas Isoladas: Contribuição de Mecanismos Redox.

BACKGROUND: Vascular dysfunction constitutes the etiology of many diseases, such as myocardial infarction and hypertension, with the disruption of redox homeostasis playing a role in the imbalance of the vasomotor control mechanism. Our group previously has shown that thyroid hormones exert protective effects on the aortic tissue of infarcted rats by improving angiogenesis signaling. OBJECTIVE: Investigate the role of triiodothyronine (T3) on vascular response, exploring its effects on isolated aortas and whether there is an involvement of vascular redox mechanisms. METHODS: Isolated aortic rings (intact- and denuded-endothelium) precontracted with phenylephrine were incubated with T3 (10-8, 10-7, 10-6, 10-5, and 10-4 M), and tension was recorded using a force-displacement transducer coupled with an acquisition system. To assess the involvement of oxidative stress, aortic rings were preincubated with T3 and subsequently submitted to an in vitro reactive oxygen species (ROS) generation system. The level of significance adopted in the statistical analysis was 5%. RESULTS: T3 (10-4 M) promoted vasorelaxation of phenylephrine precontracted aortic rings in both intact- and denuded-endothelium conditions. Aortic rings preincubated in the presence of T3 (10-4 M) also showed decreased vasoconstriction elicited by phenylephrine (1 µM) in intact-endothelium preparations. Moreover, T3 (10-4 M) vasorelaxation effect persisted in aortic rings preincubated with NG-nitro-L-arginine methylester (L-NAME, 10 µM), a nonspecific NO synthase (NOS) inhibitor. Finally, T3 (10-4 M) exhibited, in vitro, an antioxidant role by reducing NADPH oxidase activity and increasing SOD activity in the aorta's homogenates. CONCLUSION: T3 exerts dependent- and independent-endothelium vasodilation effects, which may be related to its role in maintaining redox homeostasis.

FUNDAMENTO: A disfunção vascular constitui a etiologia de diversas doenças, incluindo infarto do miocárdio e hipertensão, diante da ruptura da homeostase oxi-redutiva ("redox"), desempenhando um papel no desequilíbrio do mecanismo de controle vasomotor. Nosso grupo demonstrou anteriormente que os hormônios tireoidianos melhoram a sinalização da angiogênese, exercendo efeitos protetores sobre o tecido aórtico de ratos infartados. OBJETIVOS: Investigar o papel da triiodotironina (T3) na resposta vascular, explorando seus efeitos em aortas isoladas e a presença de mecanismos redox vasculares. MÉTODOS: Anéis aórticos isolados (endotélio intacto e desnudado) pré-contraídos com fenilefrina foram incubados com T3 (10-8, 10-7, 10-6, 10-5 e 10-4 M) e a tensão foi registrada usando um transdutor de deslocamento de força acoplado a um sistema de coleta. Para avaliar o envolvimento do estresse oxidativo, os anéis aórticos foram pré-incubados com T3 e posteriormente submetidos a um sistema de geração de espécies reativas de oxigênio (ROS) in vitro. O nível de significância adotado na análise estatística foi de 5%. RESULTADOS: A T3 (10-4 M) promoveu o vasorrelaxamento dos anéis aórticos pré-contraídos com fenilefrina em endotélio intacto e desnudado. Os anéis aórticos pré-incubados na presença de T3 (10-4 M) também mostraram diminuição da vasoconstrição provocada pela fenilefrina (1 µM) em preparações de endotélio intacto. Além disso, o efeito vasorrelaxante da T3 (10-4 M) persistiu em anéis aórticos pré-incubados com éster metílico de NG-nitro-L-arginina (L-NAME, 10 µM), um inibidor inespecífico da NO sintase (NOS). Por fim, a T3 (10-4 M) exibiu, in vitro, um papel antioxidante ao reduzir a atividade da NADPH oxidase e aumentar a atividade da SOD nos homogenatos aórticos. CONCLUSÃO: A T3 exerce efeitos dependentes e independentes de endotélio, o que pode estar relacionado ao seu papel na manutenção da homeostase redox.

Endothelial dysfunction in vascular complications of diabetes: a comprehensive review of mechanisms and implications.

Diabetic vascular complications are prevalent and severe among diabetic patients, profoundly affecting both their quality of life and long-term prospects. These complications can be classified into macrovascular and microvascular complications. Under the impact of risk factors such as elevated blood glucose, blood pressure, and cholesterol lipids, the vascular endothelium undergoes endothelial dysfunction, characterized by increased inflammation and oxidative stress, decreased NO biosynthesis, endothelial-mesenchymal transition, senescence, and even cell death. These processes will ultimately lead to macrovascular and microvascular diseases, with macrovascular diseases mainly characterized by atherosclerosis (AS) and microvascular diseases mainly characterized by thickening of the basement membrane. It further indicates a primary contributor to the elevated morbidity and mortality observed in individuals with diabetes. In this review, we will delve into the intricate mechanisms that drive endothelial dysfunction during diabetes progression and its associated vascular complications. Furthermore, we will outline various pharmacotherapies targeting diabetic endothelial dysfunction in the hope of accelerating effective therapeutic drug discovery for early control of diabetes and its vascular complications.

Oscillatory shear stress promotes endothelial senescence and atherosclerosis via STING activation.

Endothelial dysfunction is an initiating factor in atherosclerosis. Endothelial cells (ECs) are constantly subject to blood flow shear stress, and atherosclerotic plaques tend to occur in aortic bends or bifurcations impaired by low oscillatory shear stress (OSS). However, the mechanism that how OSS affects the initiation and progression of atherosclerosis remains to be explored. Here, we first reported that OSS can promote endothelial dysfunction and atherogenesis in vivo and in vitro by activating STING pathway. Mechanistically, at atherosclerosis-prone areas, OSS caused mitochondria damage in ECs, leading to the leakage of mitochondrial DNA (mtDNA) into the cytoplasm. The cytoplasmic mtDNA was recognized by cGAS to produce cGAMP, activating the STING pathway and leading to endothelial senescence, which resulted in endothelial dysfunction and atherosclerosis. We found that STING was activated in plaques of atherosclerotic patients and in aortic arch ECs of high-fat diet (HFD)-fed ApoeKO mice, as well as in ECs exposed to OSS. STING-specific deficiency in ECs attenuates endothelial senescence and resulted in a significant reduction in aortic arch plaque area in HFD-fed ApoeKO mice. Consistently, specific deficiency or pharmacological inhibition of STING attenuated OSS-induced senescence and endothelial dysfunction. Pharmacological depletion of mtDNA ameliorated OSS-induced senescence and endothelial dysfunction. Taken together, our study linked hemodynamics and endothelial senescence, and revealed a novel mechanism by which OSS leads to endothelial dysfunction. Our study provided new insights into the development of therapeutic strategies for endothelial senescence and atherosclerosis.

Resolvin D2 prevents vascular remodeling, hypercontractility and endothelial dysfunction in obese hypertensive mice through modulation of vascular and proinflammatory factors.

During resolution of inflammation, specialized proresolving mediators (SPMs), including resolvins, are produced to restore tissue homeostasis. We hypothesized that there might be a dysregulation of SPMs pathways in pathological vascular remodeling and that resolvin D2 (RvD2) might prevent vascular remodeling and contractile and endothelial dysfunction in a model of obesity and hypertension. In aortic samples of patients with or without abdominal aortic aneurysms (AAA), we evaluated gene expression of enzymes involved in SPMs synthesis (ALOXs), SPMs receptors and pro-inflammatory genes. In an experimental model of aortic dilation induced by high fat diet (HFD, 60%, eighteen weeks) and angiotensin II (AngII) infusion (four weeks), we studied the effect of RvD2 administration in aorta and small mesenteric arteries structure and function and markers of inflammation. In human macrophages we evaluated the effects of AngII and RvD2 in macrophages function and SPMs profile. In patients, we found positive correlations between AAA and obesity, and between AAA and expression of ALOX15, RvD2 receptor GPR18, and pro-inflammatory genes. There was an inverse correlation between the expression of aortic ALOX15 and AAA growth rate. In the mice model, RvD2 partially prevented the HFD plus AngII-induced obesity and adipose tissue inflammation, hypertension, aortic and mesenteric arteries remodeling, hypercontratility and endothelial dysfunction, and the expression of vascular proinflammatory markers and cell apoptosis. In human macrophages, RvD2 prevented AngII-induced impaired efferocytosis and switched SPMs profile. RvD2 might represent a novel protective strategy in preventing vascular damage associated to hypertension and obesity likely through effects in vascular and immune cells.

Unveiling the role of PD-L1 in vascular endothelial dysfunction: Insights into the mtros/NLRP3/caspase-1 mediated pyroptotic pathway.

BACKGROUND: Programmed death ligand-1(PD-L1) has been postulated to play a crucial role in the regulation of barrier functions of the vascular endothelium, yet how this novel molecule mediates dysfunction in endothelial cells (ECs) during acute lung injury (ALI) remains largely unknown. METHODS: PD-L1 siRNA and plasmids were synthesized and applied respectively to down- or up-regulate PD-L1 expression in human lung microvascular endothelial cells (HMVECs). RNA sequencing was used to explore the differentially expressed genes following PD-L1 overexpression. The expression levels of tight junction proteins (ZO-1 and occludin) and the signaling pathways of NLRP-3/caspase-1/pyroptosis were analyzed. A mouse model of indirect ALI was established through hemorrhagic shock (HEM) followed by cecal ligation and puncture (CLP), enabling further investigation into the effects of intravenous delivery of PD-L1 siRNA. RESULTS: A total of 1502 differentially expressed genes were identified, comprising 532 down-regulated and 970 up-regulated genes in ECs exhibiting PD-L1overexpression. Enrichment of PD-L1-correlated genes were observed in the NOD-like receptor signaling pathway and the TNF signaling pathway. Western blot assays confirmed that PD-L1 overexpression elevated the expression of NLRP3, cleaved-caspase-1, ASC and GSDMD, and concurrently diminished the expression of ZO-1 and occludin. This overexpression also enhanced mitochondrial oxidative phosphorylation and mitochondrial reactive oxygen species (mtROS) production. Interestingly, mitigating mitochondrial dysfunction with mitoQ partially countered the adverse effects of PD-L1 on the functionality of ECs. Furthermore, intravenous administration of PD-L1 siRNA effectively inhibited the activation of the NLRP3 inflammasome and pyroptosis in pulmonary ECs, subsequently ameliorating lung injury in HEM/CLP mice. CONCLUSION: PD-L1-mediated activation of the inflammasome contributes significantly to the disruption of tight junction and induction of pyroptosis in ECs, where oxidative stress associated with mitochondrial dysfunction serves as a pivotal mechanism underpinning these effects.

Remnant cholesterol trajectory and subclinical arteriosclerosis: a 10-year longitudinal study of Chinese adults.

We aimed to identify different trajectories of remnant cholesterol (RC) and investigate the association of RC trajectories with vascular endothelial function and atherosclerosis progression in a longitudinal cohort of the Chinese population. A total of 521 participants were included in the flow-mediated vasodilation (FMD) subcohort study, and 7775 participants were included in the brachial-ankle pulse wave velocity (baPWV) subcohort study. All participants had ≥ 3 medical examinations during the 10-year follow-up period. In the FMD subcohort study, three distinct RC trajectories were identified according to the RC range and changing pattern over time: "low" (57.58%), "moderate" (30.90%) and "high" (11.52%). The proportion of the three groups with vascular endothelial dysfunction (FMD < 7.0%) was 20.00%, 39.75% and 60.00% respectively. Taking the low group as a reference, participants in the moderate and high groups had over 1.88 and 2.94 times the odds of vascular endothelial dysfunction (P = 0.048). In the baPWV subcohort study, three distinct RC trajectories were also identified: "low" (54.29%), "moderate" (38.97%) and "high" (6.74%). The proportion of the three groups with atherosclerosis (baPWV > 1400 cm/s) was 38.79%, 51.26% and 59.01% respectively. Taking the low group as a reference, participants in the moderate and high groups had over 1.46 and 2.16 times the odds of atherosclerosis (P < 0.001). The findings indicated that distinct RC trajectories are significantly associated with vascular endothelial function and atherosclerosis. Regular monitoring to identify persistent increases in RC may be more helpful in identifying individuals with a high risk of cardiovascular disease.

Neurotensin modulates ovarian vascular permeability via adherens junctions.

Neurotensin (NTS) is a 13-amino acid peptide which is highly expressed in the mammalian ovary in response to the luteinizing hormone surge. Antibody neutralization of NTS in the ovulatory follicle of the cynomolgus macaque impairs ovulation and induces follicular vascular dysregulation, with excessive pooling of red blood cells in the follicle antrum. We hypothesize that NTS is an essential intrafollicular regulator of vascular permeability. In the present study, follicle injection of the NTS receptor antagonist SR142948 also resulted in vascular dysregulation. To measure vascular permeability changes in vitro, primary macaque ovarian microvascular endothelial cells (mOMECs) were enriched from follicle aspirates and studied in vitro. When treated with NTS, permeability of mOMECs decreased. RNA sequencing (RNA-Seq) of mOMECs revealed high mRNA expression of the permeability-regulating adherens junction proteins N-cadherin (CDH2) and K-cadherin (CDH6). Immunofluorescent detection of CDH2 and CDH6 confirmed expression and localized these cadherins to the cell-cell boundaries, consistent with function as components of adherens junctions. mOMECs did not express detectable levels of the typical vascular endothelial cadherin, VE-cadherin (CDH5) as determined by RNA-Seq, qPCR, western blot, and immunofluorescence. Knockdown of CDH2 or CDH6 via siRNA abrogated the NTS effect on mOMEC permeability. Collectively, these data suggest that NTS plays an ovulation-critical role in vascular permeability maintenance, and that CDH2 and CDH6 are involved in the permeability modulating effect of NTS on the ovarian microvasculature. NTS can be added to a growing number of angiogenic regulators which are critical for successful ovulation.

Regular transient limb ischemia improves endothelial function and inhibits endothelial cell apoptosis to prevent atherosclerosis in rabbit.

AIMS: Regular transient limb ischemia (RTLI) can prevent atherosclerosis (AS) progression in hypercholesterolemic rabbits. This study aimed to investigate the minimum effective intensity and possible mechanisms of RTLI for preventing atherosclerosis. METHODS: Eighty rabbits were divided into eight groups: normal (N), high cholesterol (H), three RTLI [three RTLI cycles every other day (R3qod), three RTLI cycles daily (R3qd), and six RTLI cycles daily (R6qd), each cycle of RTLI included 5 min of limb ischemia followed by 5 min limb reperfusion], and three correlated sham RTLI [sham ischemia for 30 min once every other day (S3qod), sham ischemia for 30 min once daily (S3qd), and sham ischemia for 60 min once daily (S6qd)]. Rabbits in group N were kept normally, while the others were fed 1% cholesterol diet for 12 weeks. The RTLI and sham RTLI groups were received RTLI or sham RTLI procedure, respectively. The plaque area in the thoracic aorta was determined by oil red O staining, and quantifying the ratio of plaque area to intimal area (PA/IA). Endothelium-dependent and -independent relaxation were also determined. Endothelial cell were isolated from abdominal aorta of rabbits, and the apoptosis ratio was detected using flow cytometry. RESULTS: The PA/IA and early apoptotic cell ratio was significantly lower as well as the endothelium-dependent relaxation response was higher in group R6qd than those in groups H and S6qd, while those in the R3qod group was not significantly different from those in groups H and S3qod, as well as those in the R3qd group showed no significant difference compared to those in groups H and S3qd. CONCLUSIONS: Six cycles of RTLI daily was the optimal effective intensity to prevent AS progression in rabbits. Endothelial function improvement and apoptosis inhibition might contribute to the anti-AS effects.

[Effect of asiaticoside on systolic blood pressure and relaxation of isolated thoracic aorta of rats].

OBJECTIVE: To investigate the effect of asiaticoside on blood pressure and relaxation of thoracic aorta in rats and explore the underlying mechanism. METHODS: SD rats treated with 50 and 100 mg/kg asiaticoside by daily gavage for 2 weeks were monitored for systolic blood pressure changes, and histological changes of the thoracic aorta were evaluated using HE staining. In isolated rat endothelium-intact and endothelium-denuded thoracic aorta rings, the effects of asiaticoside on relaxation of the aortic rings were tested at baseline and following norepinephrine (NE)- and KCl-induced constriction. The vascular relaxation effect of asiaticoside was further observed in NE-stimulated endothelium-intact rat aortic rings pretreated with L-nitroarginine methyl ester, indomethacin, zinc protoporphyrin Ⅸ, tetraethyl ammonium chloride, glibenclamide, barium chloride, Iberiotoxin, 4-aminopyridine, or TASK-1-IN-1. The aortic rings were treated with KCl and NE followed by increasing concentrations of CaCl2 to investigate the effect of asiaticoside on vasoconstriction induced by external calcium influx and internal calcium release. RESULTS: Asiaticoside at 50 and 100 mg/kg significantly lowered systolic blood pressure in rats without affecting the thoracic aorta histomorphology. While not obviously affecting resting aortic rings with intact endothelium, asiaticoside at 100 mg/kg induced significant relaxation of the rings constricted by KCl and NE, but its effects differed between endothelium-intact and endothelium-denuded rings. In endothelium-intact aortic rings pretreated with indomethacin, ZnPP Ⅸ, barium chloride, glyburide, TASK-1-IN-1 and 4-aminopyridine, asiaticoside did not produce significant effect on NE-induced vasoconstriction, and tetraethylammonium, Iberiotoxin and L-nitroarginine methyl ester all inhibited the relaxation effect of asiaticoside. In KCland NE-treated rings, asiaticoside obviously inhibited CaCl2-induced vascular contraction. CONCLUSION: Asiaticoside induces thoracic aorta relaxation by mediating high-conductance calcium-activated potassium channel opening, promoting nitric oxide release from endothelial cells and regulating Ca2+ influx and outflow, thereby reducing systolic blood pressure in rats.

Deficiency of neutral cholesterol ester hydrolase 1 (NCEH1) impairs endothelial function in diet-induced diabetic mice.

BACKGROUND: Neutral cholesterol ester hydrolase 1 (NCEH1) plays a critical role in the regulation of cholesterol ester metabolism. Deficiency of NCHE1 accelerated atherosclerotic lesion formation in mice. Nonetheless, the role of NCEH1 in endothelial dysfunction associated with diabetes has not been explored. The present study sought to investigate whether NCEH1 improved endothelial function in diabetes, and the underlying mechanisms were explored. METHODS: The expression and activity of NCEH1 were determined in obese mice with high-fat diet (HFD) feeding, high glucose (HG)-induced mouse aortae or primary endothelial cells (ECs). Endothelium-dependent relaxation (EDR) in aortae response to acetylcholine (Ach) was measured. RESULTS: Results showed that the expression and activity of NCEH1 were lower in HFD-induced mouse aortae, HG-exposed mouse aortae ex vivo, and HG-incubated primary ECs. HG exposure reduced EDR in mouse aortae, which was exaggerated by endothelial-specific deficiency of NCEH1, whereas NCEH1 overexpression restored the impaired EDR. Similar results were observed in HFD mice. Mechanically, NCEH1 ameliorated the disrupted EDR by dissociating endothelial nitric oxide synthase (eNOS) from caveolin-1 (Cav-1), leading to eNOS activation and nitric oxide (NO) release. Moreover, interaction of NCEH1 with the E3 ubiquitin-protein ligase ZNRF1 led to the degradation of Cav-1 through the ubiquitination pathway. Silencing Cav-1 and upregulating ZNRF1 were sufficient to improve EDR of diabetic aortas, while overexpression of Cav-1 and downregulation of ZNRF1 abolished the effects of NCEH1 on endothelial function in diabetes. Thus, NCEH1 preserves endothelial function through increasing NO bioavailability secondary to the disruption of the Cav-1/eNOS complex in the endothelium of diabetic mice, depending on ZNRF1-induced ubiquitination of Cav-1. CONCLUSIONS: NCEH1 may be a promising candidate for the prevention and treatment of vascular complications of diabetes.

HIV Infection, Antiretroviral Drugs, and the Vascular Endothelium.

Endothelial cell activation, injury, and dysfunction underlies the pathophysiology of vascular diseases and infections associated with vascular dysfunction, including human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome. Despite viral suppression with combination antiretroviral therapy (ART), people living with HIV (PLWH) are prone to many comorbidities, including neurological and neuropsychiatric complications, cardiovascular and metabolic diseases, premature aging, and malignancies. HIV and viral proteins can directly contribute to the development of these comorbidities. However, with the continued high prevalence of these comorbidities despite viral suppression, it is likely that ART or some antiretroviral (ARVs) drugs contribute to the development and persistence of comorbid diseases in PLWH. These comorbid diseases often involve vascular activation, injury, and dysfunction. The purpose of this manuscript is to review the current literature on ARVs and the vascular endothelium in PLWH, animal models, and in vitro studies. I also summarize evidence of an association or lack thereof between ARV drugs or drug classes and the protection or injury/dysfunction of the vascular endothelium and vascular diseases.