Vascular Cell Function Research Articles

Research advance of Nrf2 on atherosclerosis by regulating vascular smooth muscle cell.

Atherosclerosis is a common pathological change in cardiovascular disease. Vascular smooth muscle cell is the main source of plaque cell and extracellular matrix, and nuclear factor-erythroid 2-related factor 2 (Nrf2) is a key transcription factor regulating the function of vascular smooth muscle cell. In the process of atherosclerosis, Nrf2 signaling pathway has the following regulatory effects on vascular smooth muscle cell: regulating the phenotype of vascular smooth muscle cell to change to the direction conducive to the alleviation of disease progression; inhibiting the proliferation and migration of vascular smooth muscle cell; mitigating the level of blood lipid; alleviating vascular smooth muscle cell calcification, aging and apoptosis process. This article reviews the specific mechanisms of Nrf2 regulating atherosclerosis, such as phenotypic transformation, proliferation and migration, lipid metabolism, calcification, aging and apoptosis in atherosclerosis, in order to provide a basis for understanding the molecular mechanism of atherosclerosis development and finding therapeutic targets.

Alternative C3 Complement System: Lipids and Atherosclerosis.

Familial hypercholesterolemia (FH) is increasingly associated with inflammation, a phenotype that persists despite treatment with lipid lowering therapies. The alternative C3 complement system (C3), as a key inflammatory mediator, seems to be involved in the atherosclerotic process; however, the relationship between C3 and lipids during plaque progression remains unknown. The aim of the study was to investigate by a systems biology approach the role of C3 in relation to lipoprotein levels during atherosclerosis (AT) progression and to gain a better understanding on the effects of C3 products on the phenotype and function of human lipid-loaded vascular smooth muscle cells (VSMCs). By mass spectrometry and differential proteomics, we found the extracellular matrix (ECM) of human aortas to be enriched in active components of the C3 complement system, with a significantly different proteomic signature in AT segments. Thus, C3 products were more abundant in AT-ECM than in macroscopically normal segments. Furthermore, circulating C3 levels were significantly elevated in FH patients with subclinical coronary AT, evidenced by computed tomographic angiography. However, no correlation was identified between circulating C3 levels and the increase in plaque burden, indicating a local regulation of the C3 in AT arteries. In cell culture studies of human VSMCs, we evidenced the expression of C3, C3aR (anaphylatoxin receptor) and the integrin αMβ2 receptor for C3b/iC3b (RT-PCR and Western blot). C3mRNA was up-regulated in lipid-loaded human VSMCs, and C3 protein significantly increased in cell culture supernatants, indicating that the C3 products in the AT-ECM have a local vessel-wall niche. Interestingly, C3a and iC3b (C3 active fragments) have functional effects on VSMCs, significantly reversing the inhibition of VSMC migration induced by aggregated LDL and stimulating cell spreading, organization of F-actin stress fibers and attachment during the adhesion of lipid-loaded human VSMCs. This study, by using a systems biology approach, identified molecular processes involving the C3 complement system in vascular remodeling and in the progression of advanced human atherosclerotic lesions.

Gastric cancer derived exosomes mediate the delivery of circRNA to promote angiogenesis by targeting miR-29a/VEGF axis in endothelial cells

Accumulating evidence has been found that circular RNA (circRNA) plays a critical role in the initiation and development of various diseases by modulating gene expression in the cytoplasm. However, the role of circ_0044366 (termed circ29) in gastric cancer (GC) has yet to be elusive. We detected that exosomal circ29 was confirmed to be highly expressed in GC and can significantly impair the proliferation, migration, tube formation of HUVEC by exosomal communication. Interestingly, this effect could be blocked by the effect of miR-29a. In brief, we confirmed that circ29, as a sponge of miR-29a, plays a responsible role in the occurrence and development of GC by regulating the VEGF pathway. Therefore, it may be used as a potential target for the treatment of GC.

Thrombospondin‐1 Plays an Essential Role in Hippo Signaling During the Early Phase of Trypanosoma cruzi Infection in Heart Endothelial Cells

Trypanosoma cruzi is an obligate intracellular hemoflagellate parasite which cause Chagas disease. This neglected tropical disease causes severe morbidity and mortality in endemic regions. 30% of chronically infected people suffer from cardiac disorder. Chagas heart diseasecan lead to sudden death due to cardiac arrhythmias or progressive heart failure. Invasive trypomastigotes released from infected cells can be carried in vascular endothelial system to infect neighboring and distant cells. During the process of cellular infection, the parasite induces host cells to increase the levels of host thrombospondin-1 (TSP-1) to enable the process of infection. TSP-1 plays important roles in the functioning of vascular cells including vascular endothelial cells with important implications in cardiovascular health. Hippo signaling components, including yes-associated protein 1 (YAP)/transcriptional coactivator with PDZ-binding motif (TAZ), which are upstream of TSP-1 have been linked to the pathophysiology of heart disease. The molecular mechanisms by which T. cruzi signals and eventually infect heart endothelial cells remain unknown. To evaluate the importance of TSP-1 expression in heart endothelial cells during the process of T. cruzi infection, we challenge heart endothelial cells prepared from Wild Type and TSP-1 Knockout mouse (MHEC) to invasive T. cruzi trypomastigotes at different time points and evaluated changes in the Hippo signaling cascade using immunoblotting and immunofluorescence assays. We found that the parasite turned off the hippo signaling pathway in TSP-1KO heart endothelial cells. The levels of SAV1 and MOB1A increased to a maximum of 2.70±0.23 and 5.74±1.45 fold at 3 and 6 h, respectively, in TSP-1KO MHEC compared to WT MHEC following parasite challenge. This was accompanied by a significant continuous increase in the nuclear translocation of downstream effector molecule YAP to a maximum mean nuclear fluorescence intensity of 10.14±0.40 at 6 h compared to wild type cells. Besides this, we found that increased nuclear translocated YAP significantly colocalized with the transcription co-activator molecule pan-TEAD with a maximum Pearson's correlation coefficient of 0.51±0.06 at 6 h compared to YAP-Pan-TEAD colocalization in the WT MHEC, which decreased significantly with to a minimum Pearson's correlation coefficient of 0.30±0.01 at 6 h. Our finding suggests that upregulated TSP-1 is essential for the regulation of the hippo signaling pathway during the early phase of infection. These studies advance our understanding of the Host-Parasite molecular interactions occurring between heart endothelial cells and T. cruzi in the presence and absence of TSP-1. Taken together, this further supports our concept that an increase in the level of TSP-1 induced by the parasite is essential for T. cruzi infection and pathogenesis.

Dysregulated lncRNA TUG1 in different pulmonary artery cells under hypoxia.

BackgroundAt present, the role of lncRNAs in the pathogenesis of hypoxia-induced pulmonary hypertension (HPH) is not fully understood. This study aimed to explore differences in the hypoxia-induced expression of lncRNAs and their potential role in multiple pulmonary artery cells.MethodsLncRNA expression in pulmonary artery smooth muscle cells (PASMCs), pulmonary microvascular endothelial cells (PMECs), and pericytes (PCs) was analyzed by high-throughput sequencing and compared between normoxic and hypoxic cells. Bioinformatics analysis was conducted to predict their functions.ResultsPASMCs, PMECs, and PCs displayed 275 (140 upregulated), 251 (162 upregulated), and 290 (176 upregulated) different lncRNAs, respectively. Among these, lncRNA TUG1 levels increased in PASMCs and PCs but decreased in PMECs. Bioinformatics analysis indicated that lncRNA TUG1 might target miR-145-5p, thereby affecting SOX4 and BMF expression, and could also regulate miR-129-5p levels to affect CYP1B1 and VCP expression. It could also regulate miR-138-5p levels to affect KCNK3 and RHOC expression.ConclusionsHypoxia exposure of vascular cells resulted in differential expression of lncRNAs, especially lncRNA TUG1, which showed significant abnormal expression in all three types of vascular cells under hypoxia. Our results suggested that abnormal expression of lncRNA TUG1 might be involved in the regulation of pulmonary vascular cell function under hypoxia.

Urantide alleviates the symptoms of atherosclerotic rats in vivo and in vitro models through the JAK2/STAT3 signaling pathway

Atherosclerosis is the leading cause of human death, and its occurrence and development are related to the urotensin II (UII) and UII receptor (UT) system and the biological function of vascular smooth muscle cells (VSMCs). During atherosclerosis, impaired biological function VSMCs may promote atherosclerotic plaque formation. The Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway is an important mediator of signal transduction; however, the role of this signaling pathway in atherosclerosis and VSMCs remains unknown. This study aimed to investigate the effects of urantide on the JAK2/STAT3 signaling pathway in atherosclerosis. We examined the effect of urantide on the UII/UT system and the JAK2/STAT3 signaling pathway in a high fat diet induced atherosclerosis rat model and studied the effect and mechanism of urantide on the phenotypic transformation of VSMCs. We found that the UII/UT system and JAK2/STAT3 signaling pathway were highly activated in the thoracic aorta in atherosclerotic rats and in ox-LDL- and UII-induced VSMCs. After urantide treatment, the pathological changes in atherosclerotic rats were effectively improved, and the activities of the UII/UT system and JAK2/STAT3 signaling pathway were inhibited. Moreover, urantide effectively inhibited proliferation and migration and reversed the phenotypic transformation of VSMCs. These results demonstrated that urantide may control the JAK2/STAT3 signaling pathway by antagonizing the UII/UT system, thereby maintaining the biological function of VSMCs and potentially preventing and curing atherosclerosis.

Does exercise training improve the function of vascular smooth muscle? A systematic review and meta-analysis

ABSTRACT We aimed to determine the effects of exercise training on the function of vascular smooth muscle cells. PubMed and Web of Science about the effects of exercise training on vascular smooth muscle cells were searched up to August 2020. The effect sizes were estimated in terms of the standardized mean difference. The number of studies included was thirty-five overall. Exercise training had positive effects on vascular smooth muscle cells function in participants older than 40. Effect sizes for HIGH intensity and MIX were positive but small, and also when training duration was longer than 12 weeks. We concluded that vascular smooth muscle cells response can be promoted by exercise training. Vigorous aerobic exercise and mixture training modality were the best ways to promote the dilation response of vascular smooth muscle cells. Additionally, the significant improvement induced by exercise training only occurred when training lasted for longer than 12 weeks.

MICRORNA PROFILE IN HUMAN VASCULAR SMOOTH MUSCLE CELLS FROM HYPERTENSIVE SUBJECTS: FOCUS ON OXIDATIVE AND ENDOPLASMIC RETICULUM STRESS

Objective: miRNAs are important to phenotypic control and function of vascular smooth muscle cells (VSMC). miRNA dysregulation is associated with vascular dysfunction, which involves oxidative and endoplasmic reticulum (ER) stress. We assessed VSMC miRNA profile in human hypertension focusing on oxidative and ER stress pathways. Design and method: VSMCs from small arteries from normotensive (NT) and hypertensive (HT) subjects were used. miRNA profiling of 758 miRNAs was performed using TaqMan advanced miRNA assay (TaqMan Low Density Array Human microRNA). Expression of vascular genes and proteins was detected by RT-PCR and immunoblotting respectively. Ingenuity Pathway Analysis (IPA) was used for miRNA target prediction (high predicted results). Results: miRNA array identified 25 miRNAs uniquely expressed in HT and 21 miRNAs uniquely expressed in NT (CT < 30). Of the 332 miRNAs present in both HT and NT, 60 miRNAs were significantly upregulated in HT (fold change >1.5), 136 miRNAs were significantly downregulated in HT (fold change >1.5). In HT, mRNA levels of Nox1 (1.71 fold) and protein levels of Nox4 (1.59 fold) and Nox5 (2.04 fold) were increased, p < 0.05. SOD2 (4.43 fold) and GPx1 (1.97 fold) protein expression were upregulated in HT, p < 0.05. PERK (1.57 fold) and elF2a (2.31 fold) protein levels were increased in HT, while ERO1A expression was decreased in HT (2.36 fold), p < 0.05. IPA was performed for the genes differentially expressed in HT compared to NT. After inversely pairing the miRNAs to the changes observed in gene and proteins expression, miR-505–5p (-2.13 fold), miR-324-5p (-1.51 fold), miR-185-5p (-1.742) and miR-491-5p (-1.667), which are predicted to target Nox5, were downregulated. miR-185-5p and miR-491-5p together with, miR-125a-3p (-2.04 fold) and miR-634 (unique in NT, CT = 27.36) were predicted to target GPx1. ER stress was also targeted by downregulated miRNAs in HT, such as miR-200b-3p (-28.57 fold), predicted to target elF2a. Conclusions: We identify a cluster of downregulated miRNAs in human hypertension that are linked to pathways that regulate oxidative and ER stress. These findings provide new molecular insights into processes underlying VSMC redox-sensitive dysfunction and may elucidate vascular miRNA signatures in human hypertension.

Modification of histones by hypochlorous acid and its influence on vascular cell function

Modification of histones by hypochlorous acid and its influence on vascular cell function

The Emerging Role of Long Non-coding RNAs and Circular RNAs in Coronary Artery Disease.

Coronary artery disease (CAD) is a common disorder caused by atherosclerotic processes in the coronary arteries. This condition results from abnormal interactions between numerous cell types in the artery walls. The main participating factors in this process are accumulation of lipid deposits, endothelial cell dysfunction, macrophage induction, and changes in smooth muscle cells. Several lines of evidence underscore participation of long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) in the pathogenesis of CAD. Several lncRNAs such as H19, ANRIL, MIAT, lnc-DC, IFNG-AS1, and LEF1-AS1 have been shown to be up-regulated in the biological materials obtained from CAD patients. On the other hand, Gas5, Chast, HULC, DICER1-AS1, and MEG3 have been down-regulated in CAD patients. Meanwhile, a number of circRNAs have been demonstrated to influence function of endothelial cells or vascular smooth muscle cells, thus contributing to the pathogenesis of CAD. In the current review, we summarize the function of lncRNAs and circRNAs in the development and progression of CAD.

Non-Transferrin-Bound Iron in the Spotlight: Novel Mechanistic Insights into the Vasculotoxic and Atherosclerotic Effect of Iron.

Significance: While atherosclerosis is an almost inevitable consequence of aging, food preferences, lack of exercise, and other aspects of the lifestyle in many countries, the identification of new risk factors is of increasing importance to tackle a disease, which has become a major health burden for billions of people. Iron has long been suspected to promote the development of atherosclerosis, but data have been conflicting, and the contribution of iron is still debated controversially.Recent Advances: Several experimental and clinical studies have been recently published about this longstanding controversial problem, highlighting the critical need to unravel the complexity behind this topic.Critical Issues: The aim of the current review is to provide an overview of the current knowledge about the proatherosclerotic impact of iron, and discuss the emerging role of non-transferrin-bound iron (NTBI) as driver of vasculotoxicity and atherosclerosis. Finally, I will provide detailed mechanistic insights on the cellular processes and molecular pathways underlying iron-exacerbated atherosclerosis. Overall, this review highlights a complex framework where NTBI acts at multiple levels in atherosclerosis by altering the serum and vascular microenvironment in a proatherogenic and proinflammatory manner, affecting the functionality and survival of vascular cells, promoting foam cell formation and inducing angiogenesis, calcification, and plaque destabilization.Future Directions: The use of additional iron markers (e.g., NTBI) may help adequately predict predisposition to cardiovascular disease. Clinical studies are needed in the aging population to address the atherogenic role of iron fluctuations within physiological limits and the therapeutic value of iron restriction approaches. Antioxid. Redox Signal. 35, 387–414.

Vascular endothelial and smooth muscle cell galvanotactic response and differential migratory behavior

Chronic disease or injury of the vasculature impairs the functionality of vascular wall cells particularly in their ability to migrate and repair vascular surfaces. Under pathologic conditions, vascular endothelial cells (ECs) lose their non-thrombogenic properties and decrease their motility. Alternatively, vascular smooth muscle cells (SMCs) may increase motility and proliferation, leading to blood vessel luminal invasion. Current therapies to prevent subsequent blood vessel occlusion commonly mechanically injure vascular cells leading to endothelial denudation and smooth muscle cell luminal migration. Due to this dichotomous migratory behavior, a need exists for modulating vascular cell growth and migration in a more targeted manner. Here, we examine the efficacy of utilizing small direct current electric fields to influence vascular cell-specific migration (“galvanotaxis”). We designed, fabricated, and implemented an in vitro chamber for tracking vascular cell migration direction, distance, and displacement under galvanotactic influence of varying magnitude. Our results indicate that vascular ECs and SMCs have differing responses to galvanotaxis; ECs exhibit a positive correlation of anodal migration while SMCs exhibit minimal change in directional migration in relation to the electric field direction. SMCs exhibit less motility response (i.e. distance traveled in 4 h) compared to ECs, but SMCs show a significantly higher motility at low electric potentials (80 mV/cm). With further investigation and translation, galvanotaxis may be an effective solution for modulation of vascular cell-specific migration, leading to enhanced endothelialization, with coordinate reduced smooth muscle in-migration.

Hydroxyindole o-methyltransferase in 5-methoxytryptop-han synthesis and function in vascular smooth muscle cells

Hydroxyindole o-methyltransferase in 5-methoxytryptop-han synthesis and function in vascular smooth muscle cells

24S-hydroxycholesterol: Cellular effects and variations in brain diseases.

The adult brain exhibits a characteristic cholesterol homeostasis, with low synthesis rate and active catabolism. Brain cholesterol turnover is possible thanks to the action of the enzyme cytochrome P450 46A1 (CYP46A1) or 24-cholesterol hydroxylase, that transforms cholesterol into 24S-hydroxycholesterol (24S-HC). But before crossing the blood-brain barrier (BBB), this oxysterol, that is the most abundant in the brain, can act locally, affecting the functioning of neurons, astrocytes, oligodendrocytes, and vascular cells. The first part of this review addresses different aspects of 24S-HC production and elimination from the brain. The second part concentrates in the effects of 24S-HC at the cellular level, describing how this oxysterol affects cell viability, amyloid β production, neurotransmission, and transcriptional activity. Finally, the role of 24S-HC in Alzheimer, Huntington and Parkinson diseases, multiple sclerosis and amyotrophic lateral sclerosis, as well as the possibility of using this oxysterol as predictive and/or evolution biomarker in different brain disorders is discussed.

Empagliflozin impairs smooth muscle cell proliferation, accelerates endothelial regeneration, and prevents neointima formation by altered expression of the vasoactive peptide apelin

Abstract Background Empagliflozin, an inhibitor of the sodium glucose co-transporter 2 (SGLT2), developed as an anti-diabetic agent exerts additional beneficial effects on heart failure outcomes in patients with type 2 diabetes mellitus at high cardiovascular risk. However, the effect of empagliflozin on vascular cell function and vascular remodeling processes remain largely elusive. Methods/Results Immunocytochemistry and immunoblotting revealed SGLT2 to be expressed in human diabetic and non-diabetic smooth muscle (SMC) and endothelial cells (EC) as well as in murine femoral arteries. In vitro, empagliflozin significantly reduced serum-induced proliferation and migration of human diabetic and non-diabetic SMCs in a dose-dependent manner without any toxic or apoptotic effects. In contrast, empagliflozin significantly increased the cell count and migrational capacity of human diabetic ECs, but not of human non-diabetic ECs. In vivo, therapeutic application of empagliflozin (225 mg/kg medicated diet) resulted in a significantly reduced number of Ki-67+ proliferating neointimal cells in response to femoral artery wire-injury in C57BL/6J mice. Empagliflozin furthermore prevented subsequent neointima formation (luminal stenosis 91.2% vs. 80.6% at 21 days; P<0.05). Comparable effects of empagliflozin were observed in a streptozocin-induced diabetic model of apolipoprotein E−/− mice. Conclusive to the in vitro-results, re-endothelialization was not significantly affected in C57BL/6 mice (non-reendothelialized distance 2.57 mm vs. 2.3 mm; P=0.07), but even significantly improved in diabetic mice after treatment with empagliflozin (3.1 mm vs. 2.58 mm; P<0.001) assessed by Evan's Blue staining 3 days after electric denudation of the murine carotid artery. Microarray analysis of human SMCs identified the vasoactive peptide apelin to be decisively regulated in response to empagliflozin treatment. Further pathway analysis exhibited apelin to prevent SMC proliferation by de-phosphorylation of Akt and to augment EC proliferation by phosphorylation of p38 MAPK. Conclusion These data document the functional impact of empagliflozin on vascular SMCs and ECs for the first time. Empagliflozin significantly reduces serum-induced proliferation and migration of SMCs in vitro and prevented neointima formation in vivo, while augmenting EC proliferation in vitro and re-endothelialization in vivo after vascular injury. Thus, empagliflozin holds promise to exert favorable effects on vascular healing, and to prevent neointima formation following vascular injury in diabetic and non-diabetic patients. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Hannover Medical School, Martin-Luther-University Halle-Wittenberg

Stem/Progenitor Cells and Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by endothelial dysfunction and vascular remodeling. Despite significant advancement in our understanding of the pathogenesis of PAH in recent years, treatment options for PAH are limited and their prognosis remains poor. PAH is now seen as a severe pulmonary arterial vasculopathy with structural changes driven by excessive vascular proliferation and inflammation. Perturbations of a number of cellular and molecular mechanisms have been described, including pathways involving growth factors, cytokines, metabolic signaling, elastases, and proteases, underscoring the complexity of the disease pathogenesis. Interestingly, emerging evidence suggests that stem/progenitor cells may have an impact on disease development and therapy. In preclinical studies, stem/progenitor cells displayed an ability to promote endothelial repair of dysfunctional arteries and induce neovascularization. The stem cell-based therapy for PAH are now under active investigation. This review article will briefly summarize the updates in the research field, with a special focus on the contribution of stem/progenitor cells to lesion formation via influencing vascular cell functions and highlight the potential clinical application of stem/progenitor cell therapy to PAH.

Undercarboxylated osteocalcin has no adverse effect on endothelial function in rabbit aorta or human vascular cells.

Undercarboxylated osteocalcin (ucOC) improves glucose metabolism; however, its effects on endothelial cell function are unclear. We examined the biological effect of ucOC on endothelial function in animal models ex vivo and human cells in vitro. Isometric tension and immunohistochemistry techniques were used on the aorta of male New Zealand white rabbits and cell culture techniques were used on human aortic endothelial cells (HAECs) to assess the effect of ucOC in normal and high‐glucose environments. Overall, ucOC, both 10 and 30 ng/ml, did not significantly alter acetylcholine‐induced blood vessel relaxation in rabbits (p > .05). UcOC treatment did not cause any significant changes in the immunoreactivity of cellular signalling markers (p > .05). In HAEC, ucOC did not change any of the assessed outcomes (p > .05). UcOC has no negative effects on endothelial function which is important to reduce the risks of off target adverse effects if it will be used as a therapeutic option for metabolic disease in the future.

Context-Dependent Regulation of Nrf2/ARE Axis on Vascular Cell Function during Hyperglycemic Condition.

Diabetes mellitus is associated with an increased risk of micro and macrovascular complications. During hyperglycemic conditions, endothelial cells and vascular smooth muscle cells are exquisitely sensitive to high glucose. This high glucose-induced sustained reactive oxygen species production leads to redox imbalance, which is associated with endothelial dysfunction and vascular wall remodeling. Nrf2, a redox-regulated transcription factor plays a key role in the antioxidant response element (ARE)-mediated expression of antioxidant genes. Although accumulating data indicate the molecular mechanisms underpinning the Nrf2 regulated redox balance, understanding the influence of the Nrf2/ARE axis during hyperglycemic condition on vascular cells is paramount. This review focuses on the context-dependent role of Nrf2/ARE signaling on vascular endothelial and smooth muscle cell function during hyperglycemic conditions. This review also highlights improving the Nrf2 system in vascular tissues, which could be a potential therapeutic strategy for vascular dysfunction.

Abstract P055: Smooth Muscle Cell-specific Conditional Knockout Of Lysine (K)-specific Demethylase 6a Causes Endothelial Dysfunction, Increased Blood Pressure And Arterial Stiffness

Arterial stiffening is the progressive loss of elasticity of the large vessels resulting from age. Increased arterial stiffening has been correlated with hypertension and other cardiovascular co-morbidities. KDM6A is a histone 3 lysine demethylase whose activity increases expression of target genes via removal of silencing methylation marks on lysine 27 of histone 3 (H3K27). The precise role of H3K27me3, or its absence in aortic vascular smooth muscle cells (VSMCs), remains to be investigated. The objectives of this study were to determine the effects of loss of KDM6A on arterial stiffness, blood pressure, and vascular cell function. We generated VSMC-specific Kdm6a knockout mice of C57BL/6 background and confirmed knockout by western blot. Knockout of Kdm6a resulted in increased resting systolic blood pressure and pulse wave velocity in male mice. Pulse wave velocity (PWV) is the gold-standard method for determination of arterial stiffness. PWVs of the knockout mice were significantly increased compared to controls four weeks after Kdm6a knockout (Controls 2.62 + 0.69 mm/ms; KO 3.13 + 0.30 mm/ms; P=0.0228). Systolic blood pressure was directly obtained for each mouse via carotid cannulation. The systolic blood pressures of knockout mice were significantly increased. Mesenteric arteries were isolated from three control and three Kdm6a knockout mice and mounted onto a wire myograph. Vessels were pre-constricted with norepinephrine and vasodilation was measured by treatment with increasing doses of acetylcholine and sodium nitroprusside to assess endothelial and VSMC function. Interestingly, despite Kdm6a knockout in VSMCs, vasodilation of VSMCs was not different between control and knockout arteries, but relaxation in response to acetylcholine, which stimulates the release of nitric oxide from endothelial cells, was decreased. This suggests endothelial dysfunction. These results indicate that loss of KDM6A in VSMCs leads to elevated systolic blood pressure and arterial stiffness.

English

MiRNAs are highly conserved class of small (19-25 nucleotides), non-coding RNAs, which regulate post-transcriptional gene expression by binding to target mRNAs and result in gene silencing. In the genome, miRNAs can be found situated in the exons of non-coding genes, introns of coding and non-coding genes and the intragenic regions. Small interfering RNAs are approximately 22 nucleotides in length and mediate RNA interference (RNAi). miRNAs control endothelial cell, vascular smooth muscle cell and macrophage functions, and thereby regulate the progression of atherosclerosis. miRNAs expression is modulated by different stimuli involved in every stage of atherosclerosis and conversely miRNAs modulates several pathways implicated in plaque development such as cholesterol metabolism. miRNAs are involved in the regulation of key processes that contribute to skin fibrosis, including TGF-beta signaling, ECM deposition, fibroblast proliferation and differentiation, and epithelial to mesenchymal transition or transformation. Some miRNAs are profibrotic and their upregulation favors these processes contributing to fibrosis, while anti-fibrotic miRNAs inhibit these processes and may be reduced in fibrosis. Keywords: Micro RNA, Atherosclerosis, Skin fibrosis, Fibroblast, Plaque