Phenotypic switching of vascular smooth muscle cells in the 'normal region' of aorta from atherosclerosis patients is regulated by miR-145

MicroRNA-374 is a potential diagnostic biomarker for atherosclerosis and regulates the proliferation and migration of vascular smooth muscle cells

Background

The occurrence and development of atherosclerosis (AS) are closely related to the abnormality of vascular smooth muscle cells (VSMCs), and multiple microRNAs (miRNAs) have been reported to participate in the pathogenesis of AS. This study explored the expression and clinical value of miR-374 in the serum of AS patients, and analyzed its effect on the proliferation and migration of VSMCs.

Methods

The expression levels of miR-374 in the serum of 102 asymptomatic patients with AS and 89 healthy patients were detected by fluorescence quantitative PCR. The diagnostic value of miR-374 was evaluated through the receiver operating characteristic (ROC) curve. What's more, CCK-8 and Transwell assays were used to analyze the effects of miR-374 on the proliferation and migration of VSMCs.

Results

The expression level of miR-374 in the serum of AS patients was significantly higher than that of the control group. At the same time, the expression of miR-374 in AS patients was positively correlated with carotid intima-media thickness (CIMT). The area under the ROC curve is 0.824. Furthermore, overexpression of miR-374 significantly promoted the proliferation and migration of VSMCs, whereas reducing miR-374 inhibited the proliferation and migration of VSMCs.

Conclusions

The high expression of miR-374 may be a potential diagnostic marker for AS, and overexpression of miR-374 may play a role in AS by promoting the proliferation and migration of VSMCs.

The emerging role of cell senescence in atherosclerosis

Cell senescence is a fundamental mechanism of aging and appears to play vital roles in the onset and prognosis of cardiovascular disease, fibrotic pulmonary disease, liver disease and tumor. Moreover, an increasing body of evidence shows that cell senescence plays an indispensable role in the formation and development of atherosclerosis. Multiple senescent cell types are associated with atherosclerosis, senescent human vascular endothelial cells participated in atherosclerosis via regulating the level of endothelin-1 (ET-1), nitric oxide (NO), angiotensin II and monocyte chemoattractant protein-1 (MCP-1), senescent human vascular smooth muscle cells-mediated plaque instability and vascular calcification via regulating the expression level of BMP-2, OPN, Runx-2 and inflammatory molecules, and senescent macrophages impaired cholesterol efflux and promoted the development of senescent-related cardiovascular diseases. This review summarizes the characteristics of cell senescence and updates the molecular mechanisms underlying cell senescence. Moreover, we also discuss the recent advances on the molecular mechanisms that can potentially regulate the development and progression of atherosclerosis.

MicroRNA Regulatory Pathways in the Control of the Actin-Myosin Cytoskeleton

MicroRNAs (miRNAs) are key modulators of post-transcriptional gene regulation in a plethora of processes, including actin-myosin cytoskeleton dynamics. Recent evidence points to the widespread effects of miRNAs on actin-myosin cytoskeleton dynamics, either directly on the expression of actin and myosin genes or indirectly on the diverse signaling cascades modulating cytoskeletal arrangement. Furthermore, studies from various human models indicate that miRNAs contribute to the development of various human disorders. The potentially huge impact of miRNA-based mechanisms on cytoskeletal elements is just starting to be recognized. In this review, we summarize recent knowledge about the importance of microRNA modulation of the actin-myosin cytoskeleton affecting physiological processes, including cardiovascular function, hematopoiesis, podocyte physiology, and osteogenesis.

Inhibition of vascular calcification by microRNA-155-5p is accompanied by the inactivation of TGF-β1/Smad2/3 signaling pathway

Vascular calcification (VC) is a vital factor for cardiovascular morbidity and mortality. Accumulating data suggest that microRNA (miR) is implicated in the VC. The main purpose of this study is to study the influence of miR-155-5p overexpression on VC development in vitro and in vivo. Immunofluorescence staining, real-time PCR, alizarin red staining, alkaline phosphatase (ALP) activity assay, western blot, luciferase assay, hematoxylin-eosin (HE), Masson's trichrome staining, and calcium content assay were used in this research. The results showed that miR-155-5p was decreased in the rat vascular smooth muscle cells (rVSMCs) undergoing calcification in vitro. MiR-155-5p overexpression reversed the increase of calcification and ALP activity in calcified cells. Further, overexpression of miR-155-5p inhibited the transforming growth factor-β1 (TGF-β1)/Smad2/3 signaling pathway, as evidenced by decreased protein expression of TGF-β1, pSmad-2 and pSmad-3 in rVSMCs. MiR-155-5p was showed to target Smad2 directly. Moreover, miR-155-5p upregulation reduced vascular thickening, fibrosis and calcium content of aorta abdominalis in CaCl₂-mediated VC model. Collectively, our results suggest that miR-155-5p overexpression may inhibit VC development through suppressing TGF-β1/Smad2/3 signaling pathway in vivo and in vitro, indicating that miR-155-5p may act as a potential therapeutic target for VC-related disease.

Nicotine in Senescence and Atherosclerosis

Cigarette smoke is a known exacerbator of age-related pathologies, such as cardiovascular disease (CVD), atherosclerosis, and cellular aging (senescence). However, the role of nicotine and its major metabolite cotinine is yet to be elucidated. Considering the growing amount of nicotine-containing aerosol use in recent years, the role of nicotine is a relevant public health concern. A number of recent studies and health education sites have focused on nicotine aerosol-induced adverse lung function, and neglected cardiovascular (CV) impairments and diseases. A critical review of the present scientific literature leads to the hypothesis that nicotine mediates the effects of cigarette smoke in the CV system by increasing MAPK signaling, inflammation, and oxidative stress through NADPH oxidase 1 (Nox1), to induce vascular smooth muscle cell (VSMC) senescence. The accumulation of senescent VSMCs in the lesion cap is detrimental as it increases the pathogenesis of atherosclerosis by promoting an unstable plaque phenotype. Therefore, nicotine, and most likely its metabolite cotinine, adversely influence atherosclerosis.

MicroRNA (miRNA): A New Dimension in the Pathogenesis of Antiphospholipid Syndrome (APS)

MicroRNAs (miRNAs) are single-stranded, endogenous RNA molecules that play a significant role in the regulation of gene expression as well as cell development, differentiation, and function. Recent data suggest that these small molecules are responsible for the regulation of immune responses. Therefore, they may act as potent modulators of the immune system and play an important role in the development of several autoimmune diseases. Antiphospholipid syndrome (APS) is an autoimmune systemic disease characterized by venous and/or arterial thromboses and/or recurrent fetal losses in the presence of antiphospholipid antibodies (aPLs). Several lines of evidence suggest that like other autoimmune disorders, miRNAs are deeply involved in the pathogenesis of APS, interacting with the function of innate and adaptive immune responses. In this review, we characterize miRNAs in the light of having a functional role in the immune system and autoimmune responses focusing on APS. In addition, we also discuss miRNAs as potential biomarkers and target molecules in treating APS.

Liuwei Dihuang soft capsules inhibits the phenotypic conversion of VSMC to prevent the menopausal atherosclerosis by up-regulating the expression of myocardin

ETHNOPHARMACOLOGICAL RELEVANCE

Liuwei Dihuang (LWDH) is a classic prescription that has been used as a traditional medicinal formula for more than 1000 years in China. In clinical, LWDF is used for treating functional decline associated with senile disease and menopausal syndrome. Studies have demonstrated that LWDH could significantly improve estrogen level and ER expression, and suspend the process of atherosclerosis. However, the under mechanism of how LWDH suppressing VSMCs phenotypic conversion and proliferation through ER is still unknown.

AIM OF THE STUDY

This study was to reveal the under mechanism of how LWDH inhibits the phenotypic conversion of VSMCs.

MATERIALS AND METHODS

24 ApoE-/- mice were divided into 4 groups: sham group, model group, E₂ group, and LWDH group, and 6 C57BN/L6 mice were used as control group. The primary VSMCs were divided into control group, model group, E₂ group, LWDH group, LWDH + MPP group, and LWDH + PHTPP group with or without control siRNA, ERα siRNA, ERβ siRNA, and myocardin siRNA. Oil red staining was used to evaluate the lipid deposition in the cardiac aorta. Serum chemistry analysis to test serum TG, TC, LDL, and HDL. Immunofluorescence staining was used to test α-SMA, osteopontin and F-actin. Immunohistochemical staining was performed to check out the myocardin in the cardiac aorta. The mRNA levels of α-SMA, osteopontin, ERα, ERβ, SRC3 and myocardin were detected by Real Time-PCR, and the protein expression levels of them were detected by Western blotting. Co-immunoprecipitation was proceed to test the interaction between ERα and SRC3 and SRC3 and myocardin. Flow cytometry was used to check out the cell cycle. Wound healing assay and Transwell were managed to evaluate the migration capacity of VSMCs.

RESULTS

In vivo administration of LWDH suppressed AS symptoms, decreases phenotypic marker of vascular endothelial cell, and increases phenotypic marker of VSMC in ovariectomized ApoE-/- female mice. Moreover, LWDH significantly increased the mRNA and protein expression levels of ERα, ERβ, SRC3 and myocardin in the cardiac aorta of ovariectomized ApoE-/- female mice. In vitro, LWDH altered cell cycle and reduced the elevated cyclinD protein expression migration capacity and in the model VSMCs. In addition, LWDH inhibited phenotypic conversion and promoted the expression of ER, SRC3, and myocardin of the primary VSMC phenotypic conversion model. Inhibition of ERα almost completely eliminated the impacts of LWDH on α- SMA and osteopontin. Furthermore, LWDH promoted the interaction between ERα and SRC3 and up-regulated the co-activation of SRC3 and myocardin.

CONCLUSIONS

LWDH could inhibit the phenotypic conversion of VSMCs in vitro and in vivo by increasing the activity of myocardin through up-regulating the expression of ERα and promoting the interaction between ERα and SRC3. Our research reveals the under mechanism of how LWDH inhibits the phenotypic conversion of VSMCs.

The interaction between 30b-5p miRNA and MBNL1 mRNA is involved in vascular smooth muscle cell differentiation in patients with coronary atherosclerosis

Vascular smooth muscle cells (VSMCs) in the arterial wall have diverse functions. In pathological states, the interplay between transcripts and microRNAs (miRNAs) leads to phenotypic changes. Understanding the regulatory role of miRNAs and their target genes may reveal how VSMCs modulate the pathogenesis of coronary artery disease. Laser capture microdissection was performed on aortic wall tissues obtained from coronary artery bypass graft patients with and without recent acute myocardial infarction (MI). The mSMRT-qPCR miRNA assay platform (MiRXES, Singapore) was used to profile miRNA. The miRNA data were co-analyzed with significant mRNA transcripts. TargetScan 7.1 was applied to evaluate miRNA-mRNA interactions. The miRNA profiles of 29 patients (16 MI and 13 non-MI) were evaluated. Thirteen VSMC-related miRNAs were differentially expressed between the MI and non-MI groups. Analysis revealed seven miRNA-targeted mRNAs related to muscular tissue differentiation and proliferation. TargetScan revealed that among the VSMC-related transcripts, MBNL1 had a recognition site that matched the hsa-miR-30b-5p target seed sequence. In addition to predicted analysis, our experiment in vitro with human VSMC culture confirmed that hsa-miR-30b-5p negatively correlated with MBNL1. Our data showed that overexpression of hsa-miR-30b-5p led to downregulation of MBNL1 in VSMCs. This process influences VSMC proliferation and might be involved in VSMC differentiation.

MicroRNAs as Therapeutic Targets and Clinical Biomarkers in Atherosclerosis

Atherosclerotic cardiovascular disease remains the leading cause of morbidity and mortality worldwide. Atherosclerosis develops over several decades and is mediated by a complex interplay of cellular mechanisms that drive a chronic inflammatory milieu and cell-to-cell interactions between endothelial cells, smooth muscle cells and macrophages that promote plaque development and progression. While there has been significant therapeutic advancement, there remains a gap where novel therapeutic approaches can complement current therapies to provide a holistic approach for treating atherosclerosis to orchestrate the regulation of complex signalling networks across multiple cell types and different stages of disease progression. MicroRNAs (miRNAs) are emerging as important post-transcriptional regulators of a suite of molecular signalling pathways and pathophysiological cellular effects. Furthermore, circulating miRNAs have emerged as a new class of disease biomarkers to better inform clinical diagnosis and provide new avenues for personalised therapies. This review focusses on recent insights into the potential role of miRNAs both as therapeutic targets in the regulation of the most influential processes that govern atherosclerosis and as clinical biomarkers that may be reflective of disease severity, highlighting the potential theranostic (therapeutic and diagnostic) properties of miRNAs in the management of cardiovascular disease.

Tanshinone ⅡA inhibits homocysteine-induced proliferation of vascular smooth muscle cells via miR-145/CD40 signaling

Tanshinone IIA (Tan IIA), isolated from the traditional Chinese herb Danshen, exhibits broad cardiovascular protective effects. However, the effect of Tan IIA on Homocysteine (Hcy)-induced proliferation of vascular smooth muscle cells (VSMCs) remains unknown. We herein determined whether Tan IIA exerted anti-proliferative effect in Hcy-treating VSMCs, and further investigated the underlying mechanism (miR-145/CD40 signaling). The results showed that Tan IIA significantly inhibited VSMCs proliferation induced by Hcy in a dose-dependent manner, and reversed the VSMCs injury as indicated by decreased KLF4 and increased Calponin expression. In view of the key role of miR-145 in VSMCs, we further explored the role of miR-145 on the protective effect of Tan IIA against Hcy-induced VSMCs proliferation. The miR-145 expression was down-regulated and its targeted gene CD40 was up-regulated in Hcy-treating VSMCs, while the Tan IIA reversed the effect of Hcy, suggesting the miR-145/CD40 may be involve in the protective effect of Tan IIA. To determine the speculation, miR-145 inhibitor was used to inhibit miR-145 expression. The results indicated that miR-145 inhibitor can suppress the protective effects of Tan IIA against Hcy-induced VSMCs proliferation. Collectively, present study demonstrates that Tan IIA inhibits Hcy-induced proliferation of VSMCs via miR-145/CD40 signaling.

Inhibition of lysine-specific demethylase 1A suppresses neointimal hyperplasia by targeting bone morphogenetic protein 2 and mediating vascular smooth muscle cell phenotype

OBJECTIVES

Vascular disorders are associated with phenotypical switching of vascular smooth muscle cells (VSMCs). We investigated the effect of bone morphogenetic protein (BMP)-2 in controlling VSMC phenotype and vascular disorder progression. Lysine (K)-specific demethylase 1A (KDM1A) has been identified to target BMP-2 and is employed as a therapeutic means of regulating BMP-2 expression in VSMCs.

MATERIALS AND METHODS

VSMCs were stimulated with angiotensin II, and the expression of KDM1A and BMP-2 was detected. VSMC proliferation, apoptosis, and phenotype were evaluated. An in vivo aortic injury model was established, and VSMC behaviour was evaluated by the expression of key markers. The activation of BMP-2-associated signalling pathways was examined.

RESULTS

We confirmed the inhibitory effect of KDM1A on BMP-2 activity and demonstrated that KDM1A inhibition prevented VSMC transformation from a contractile to synthetic phenotype. In angiotensin II-treated VSMCs, KDM1A inhibition triggered a decrease in cell proliferation and inflammatory response. In vivo, KDM1A inhibition alleviated post-surgery neointimal formation and collagen deposition, preventing VSMCs from switching into a synthetic phenotype and suppressing disease onset. These processes were mediated by BMP-2 through canonical small mothers against decapentaplegic signalling, which was associated with the activation of BMP receptors 1A and 1B.

CONCLUSIONS

The regulatory correlation between KDM1A and BMP-2 offers insights into vascular remodelling and VSMC phenotypic modulation. The reported findings contribute to the development of innovative strategies against vascular disorders.

The role of microRNAs in the involvement of vascular smooth muscle cells in the development of atherosclerosis

MicroRNAs (miRNAs) are a class of nonprotein-encoding RNAs of ~22 nucleotides in length that bind to or complement each other with a target gene messenger RNA (mRNA) to promote mRNA degradation or inhibit translation of the target mRNA. The protein required [such as Toll-like receptor (TLR) proteins] is controlled at an optimal level. By affecting protein translation, miRNAs have become powerful regulators of biological processes, including development, differentiation, cell proliferation, and apoptosis. MiRNAs are involved in the regulation of proliferation, migration, and apoptosis of vascular smooth muscle cells (VSMCs), thereby affecting the formation of atherosclerosis (AS). In recent years, the role and mechanism of miRNAs involved in AS development in VSMCs have been studied extensively. In the current study, the results and progress in miRNA research are reviewed.

Exosomes: An emerging factor in atherosclerosis

Atherosclerosis is the main reason for morbidity and death caused by cardiovascular disease which leads to approximately 20% of total death around the world. Exosomes secreted by the cells is a kind of extracellular vesicles with lipid bilayer structure, containing a variety of cell specific lipid, nucleic acid and protein, involved in intercellular communication, plays an important role in different physiological and pathological process. In recent years, with the deepening of research, the role of exosomes in cardiovascular diseases has received extensive attention. This review summarizes the roles of exosomes and exosome-derived from microRNAs, proteins and DNA as biomarkers in the development of atherosclerosis, and explores the mechanism of exosome-mediated intercellular crosstalk in atherosclerosis, providing potential roles for diagnosis and treatment.

Smooth muscle-specific Gsα deletion exaggerates angiotensin II-induced abdominal aortic aneurysm formation in mice in vivo

Objective:

Abdominal aortic aneurysm (AAA) is a life-threatening vascular disease without an effective pharmaceutical treatment. Genetic studies have proved the involvement of smooth muscle phenotype switch in the development of AAA. The alpha subunit of the heterotrimeric G stimulatory protein (Gsα) mediates receptor-stimulated production of cyclic adenosine monophosphate (cAMP). However, the role of smooth muscle Gsα in AAA formation remains unknown.

Approach and results:

In this study, mice with knockout of smooth muscle-specific Gsα (Gsα^SMKO) were generated by cross-breeding Gsα^flox/flox mice with SM22-CreER^T2 transgenic mice, induced in adult mice by tamoxifen treatment. Gsα deficiency induced a smooth muscle phenotype switch from a contractile to a synthetic state. Mechanically, Gsα deletion reduced cAMP level and increased the level of human antigen R (HuR), which binds with the adenylate uridylate–rich elements of the 3′ untranslated region of Krüppel-like factor 4 (KLF4) mRNA, thereby increasing the stability of KLF4. Moreover, genetic knockdown of HuR or KLF4 rescued the phenotype switch in Gsα-deficient smooth muscle cells. Furthermore, with acute infusion of angiotensin II, the incidence of AAA was markedly higher in ApoE^−/−/Gsα^SMKO than ApoE^−/−/Gsα^flox/flox mice and induced increased elastic lamina degradation and aortic expansion. Finally, the levels of Gsα and SM α-actin were significantly lower while those of HuR and KLF4 were higher in human AAA samples than adjacent nonaneurysmal aortic sections.

Conclusions:

Gsα may play a protective role in AAA formation by regulating the smooth muscle phenotype switch and could be a potential therapeutic target for AAA disease.

hiPSCs in cardio-oncology: deciphering the genomics

The genomic predisposition to oncology-drug-induced cardiovascular toxicity has been postulated for many decades. Only recently has it become possible to experimentally validate this hypothesis via the use of patient-specific human-induced pluripotent stem cells (hiPSCs) and suitably powered genome-wide association studies (GWAS). Identifying the individual single nucleotide polymorphisms (SNPs) responsible for the susceptibility to toxicity from a specific drug is a daunting task as this precludes the use of one of the most powerful tools in genomics: comparing phenotypes to close relatives, as these are highly unlikely to have been treated with the same drug. Great strides have been made through the use of candidate gene association studies (CGAS) and increasingly large GWAS studies, as well as in vivo whole-organism studies to further our mechanistic understanding of this toxicity. The hiPSC model is a powerful technology to build on this work and identify and validate causal variants in mechanistic pathways through directed genomic editing such as CRISPR. The causative variants identified through these studies can then be implemented clinically to identify those likely to experience cardiovascular toxicity and guide treatment options. Additionally, targets identified through hiPSC studies can inform future drug development. Through careful phenotypic characterization, identification of genomic variants that contribute to gene function and expression, and genomic editing to verify mechanistic pathways, hiPSC technology is a critical tool for drug discovery and the realization of precision medicine in cardio-oncology.

Migration versus proliferation as contributor to in vitro wound healing of vascular endothelial and smooth muscle cells

Wound closure, as a result of collective cell growth, is an essential biological response to injury. In the field of vascular biology, the response of vascular smooth muscle cells (SMCs) and endothelial cells (ECs) to injury and substrate surface is important in therapeutic clinical treatment interventions such as angioplasty and atherectomy. Specifically, the mechanism by which cells close wounds (i.e. proliferation versus migration) in response to injury stimuli is of interest to better modulate recurrent vascular stenosis, prevent thrombus formation, occlusion, and life-threatening cardiovascular events. Here, we examine growth extent and temporal sequence of events following wound or gap introduction to a confluent monolayer of vascular SMCs or ECs. Significant differences in the preferred mechanisms of these cells to close wounds or gaps were observed; after 48 h, 73% of SMC wound closure was observed to be due to proliferation, while 75% of EC wound closure resulted from migration. These mechanisms were further modulated via addition or removal of extracellular matrix substrate and injury, with ECs more responsive to substrate composition and less to injury, in comparison to SMCs. Our results indicate that ECs and SMCs heal wounds differently, and that the time and mode of injury and associated substrate surface all impact this response.

Role of flow-sensitive microRNAs and long noncoding RNAs in vascular dysfunction and atherosclerosis

Atherosclerosis is the primary underlying cause of myocardial infarction, ischemic stroke, and peripheral artery disease. The disease preferentially occurs in arterial regions exposed to disturbed blood flow, in part, by altering expression of flow-sensitive coding- and non-coding genes. In this review, we summarize the role of noncoding RNAs, [microRNAs (miRNAs) and long noncoding RNAs(lncRNAs)], as regulators of gene expression and outline their relationship to the pathogenesis of atherosclerosis. While miRNAs are small noncoding genes that post-transcriptionally regulate gene expression by targeting mRNA transcripts, the lncRNAs regulate gene expression by diverse mechanisms, which are still emerging and incompletely understood. We focused on multiple flow-sensitive miRNAs such as, miR-10a, -19a, -23b, -17~92, -21, -663, -92a, -143/145, -101, -126, -712, -205, and -155 that play a critical role in endothelial function and atherosclerosis by targeting inflammation, cell cycle, proliferation, migration, apoptosis, and nitric oxide signaling. Flow-dependent regulation of lncRNAs is just emerging, and their role in vascular dysfunction and atherosclerosis is unknown. Here, we discuss the flow-sensitive lncRNA STEEL along with other lncRNAs studied in the context of vascular pathophysiology and atherosclerosis such as MALAT1, MIAT1, ANRIL, MYOSLID, MEG3, SENCR, SMILR, LISPR1, and H19. Also discussed is the use of these noncoding RNAs as potential biomarkers and therapeutics to reduce and regress atherosclerosis.

SXBX pill suppresses homocysteine-induced vascular smooth muscle cells dedifferentiation by inhibiting NLRP3 inflammasomes activation via ERK/p38 MAPK pathways

The dedifferentiation of vascular smooth muscle cells (VSMCs) is a key event in the pathogenesis of vascular remodeling-related disease. The present study aimed to investigate the effects of shexiangbaoxin (SXBX) pill, a traditional Chinese medicinal formula on VSMCs dedifferentiation and its potential mechanisms. High-fat diet (HFD) was introduced to lipoprotein receptor-deficient (LDLR^-/-) mice to generate hyperhomocysteinemia (HHcy), and plasma Hcy and lipid levels were analyzed. The phenotype of VSMCs was assessed in mice with the treatment of low (45 mg/kg/d) or high (90 mg/kg/d) SXBX pill by measuring the contractile protein α-SMA, SM22α and synthetic proteins OPN using RT-qPCR, western blotting and immunofluorescence assay. In vitro, the proliferation, migration and dedifferentiation of VSMCs were measured by MTT, Edu incorporation, wound healing and western blotting assay. Small interfering RNA technology was used to examine the role of NLRP3 in the effects of SXBX pill on dedifferentiation. The results indicated that although SXBX pill had no influence on HFD-induced HHcy and hyperlipidaemia, it reversed HHcy-induced dedifferentiation of VSMCs in vivo. SXBX pill significantly inhibited proliferation, migration and dedifferentiation of Hcy-treated VSMCs. In addition, we found that Hcy activated NLRP3 inflammasomes in VSMCs and SXBX pill could attenuate NLRP3 inflammasomes activation. Moreover, subsequent analysis suggested that SXBX pill inhibited NLRP3 inflammasomes activation through regulation of ERK1/2 and p38 MAPK pathway. Knockdown of NLRP3 reversed the inhibitory effects of SXBX pill in VSMCs. In conclusion, SXBX pill inhibited Hcy-induced proliferation, migration and dedifferentiation of VSMCs by suppressing NLRP3 inflammasomes activation via of ERK/p38 MAPK pathway.

Tissue-specific epigenetics of atherosclerosis-related ANGPT and ANGPTL genes

Aim:

To understand tissue-specific regulation of angiopoietin/angiopoietin-like (ANGPT/ANGPTL) genes (especially the five genes embedded in introns of host genes) and their association with atherosclerosis.

Methods:

Transcription and epigenomic databases from various normal tissues were examined in the vicinity of ANGPT1, ANGPT2, ANGPTL1, ANGPTL2, ANGPTL3, ANGPTL4 and ANGPTL8.

Results:

We identified tissue-specific enhancer chromatin regions that are likely to regulate transcription of ANGPT/ANGPTL genes and were intragenic, intergenic or host gene-linked. In addition, we found atherosclerosis-linked differentially methylated regions associated with ANGPT2 and with sequences encoding miR-145, a microRNA that targets ANGPT2 mRNA in cancers.

Conclusion:

Our findings implicate enhancers as major contributors to tissue-specific expression of ANGPT/ANGPTL genes, which play critical roles in angiogenesis, atherosclerosis, cancer, and inflammatory and metabolic diseases.

Connective Tissue and Age-Related Diseases

We begin this chapter by describing normal characteristics of several pertinent connective tissue components, and some of the basic changes they undergo with ageing. These alterations are not necessarily tied to any specific disease or disorders, but rather an essential part of the normal ageing process. The general features of age-induced changes, such as skin wrinkles, in selected organs with high content of connective or soft tissues are discussed in the next part of the chapter. This is followed by a section dealing with age-related changes in specific diseases that fall into at least two categories. The first category encompasses common diseases with high prevalence among mostly ageing populations where both genetic and environmental factors play roles. They include but may not be limited to atherosclerosis and coronary heart disease, type II diabetes, osteopenia and osteoporosis, osteoarthritis, tendon dysfunction and injury, age-related disorders of spine and joints. Disorders where genetics plays the primary role in pathogenesis and progression include certain types of progeria, such as Werner syndrome and Hutchinson-Gilford progeria belong to the second category discussed in this chapter. These disorders are characterized by accelerated signs and symptoms of ageing. Other hereditary diseases or syndromes that arise from mutations of genes encoding for components of connective tissue and are less common than diseases included in the first group will be discussed briefly as well, though they may not be directly associated with ageing, but their connective tissue undergoes some changes compatible with ageing. Marfan and Ehlers-Danlos syndromes are primary examples of such disorders. We will probe the role of specific components of connective tissue and extracellular matrix if not in each of the diseases, then at least in the main representatives of these disorders.

Role of pyroptosis in cardiovascular disease

Cardiac function is determined by the dynamic equilibrium of various cell types and the extracellular matrix that composes the heart. Cardiovascular diseases (CVDs), especially atherosclerosis and myocardial infarction, are often accompanied by cell death and acute/chronic inflammatory reactions. Caspase‐dependent pyroptosis is characterized by the activation of pathways leading to the activation of NOD‐like receptors, especially the NLRP3 inflammasome and its downstream effector inflammatory factors interleukin (IL)‐1β and IL‐18. Many studies in the past decade have investigated the role of pyroptosis in CVDs. The findings of these studies have led to the development of therapeutic approaches based on the regulation of pyroptosis, and some of these approaches are in clinical trials. This review summarizes the molecular mechanisms, regulation and cellular effects of pyroptosis briefly and then discusses the current pyroptosis studies in CVD research.

mircroRNA-152 prevents the malignant progression of atherosclerosis via down-regulation of KLF5

Macrophages' function play a vital role in the progression of atherosclerosis (AS), and miRNAs can modulate inflammatory cytokine secretion, lipid uptake and apoptosis of macrophages. miR-152 is down-regulated in the serum samples of AS patients and inhibits the migration of human umbilical vein endothelial cell, suggesting that miR-152 exerts a role in the atherogenesis. Nevertheless, the function of miR-152 in the inflammatory reaction of macrophages remains unexplored. Besides, bioinformatics shows that KLF5 is a direct target of miR-152. As a result, the objective of this study is to investigate the effects and mechanism of miR-152/KLF5 in the inflammatory reaction of macrophages. ApoE knockdown mouse (ApoE^-/-) fed with high fat diet (HFD) was used as animal AS models. Ox-LDL treated RAW264.7 cell was used as cell model. Results showed that miR-152 expression was reduced, while KLF5 expression was elevated in the aortic tissues of AS mice, as compared with that of the control mice. Up-regulation of miR-152 significantly reduced the elevated expression of IL-1, IL-6 and TNF-α mediated by ox-LDL in the cultural supernatant of RAW264.7 cells and reduced β-catenin expression, whereas these effects were all neutralized when KLF5 was up-regulated in the base of miR-152 up-regulation. In conclusion, this study illustrates that miR-152 alleviates the pathogenesis of AS through inhibiting inflammatory responses by targeting KLF5, in which β-catenin might involves in. Our study provides a possibility of consideration of miR-152/KLF5 as a target for AS treatment.

Phenotype of Vascular Smooth Muscle Cells (VSMCs) Is Regulated by miR-29b by Targeting Sirtuin 1

Background

Phenotypic switch of vascular smooth muscle cells (VSMCs) participates in the etiology of various vascular diseases. It has been proved that microRNAs (miRNAs) serve as crucial regulators of functions of VSMCs. This study aimed to discover how miR-29b regulates the transformation of VSMCs phenotypes in mice.

Material/Methods

Primary VSMCs of aorta in mice were cultured in DMEM medium. A series of experiments involving transfection of oligonucleotides in cultured VSMCs, quantitative reverse transcription PCR (qRT-PCR), luciferase reporter assay, and Western blotting analysis were performed in this study.

Results

We found that in VSMCs cultured in presence of stimulator, platelet-derived growth factor-BB (PDGF-BB), miR-29b was upregulated significantly and expressions of VSMC-phenotype-related genes (α-SMA, calponin, and SM-MHC) were regulated by miR-29b. Moreover, through downregulation of sirtuin 1 (SIRT1), miR-29b affects phenotypic transformation of VSMCs. Luciferase report assay identified a significant increase of SIRT1 3′-UTR activity in treatment with miR-29b inhibitor, which, however, was reversed in the presence of miR-29b mimic. Suppression of miR-29b reversed the activation of NF-κB induced by PDGF-BB in VSMCs.

Conclusions

We concluded that miR-29b is an important regulator in the PDGF-BB-mediated VSMC phenotypic transition by targeting SIRT1. Interventions aimed at miR-29b may be promising in treating numerous proliferative vascular disorders.

Conditional and interaction gene-set analysis reveals novel functional pathways for blood pressure

Gene-set analysis provides insight into which functional and biological properties of genes are aetiologically relevant for a particular phenotype. But genes have multiple properties, and these properties are often correlated across genes. This can cause confounding in a gene-set analysis, because one property may be statistically associated even if biologically irrelevant to the phenotype, by being correlated with gene properties that are relevant. To address this issue we present a novel conditional and interaction gene-set analysis approach, which attains considerable functional refinement of its conclusions compared to traditional gene-set analysis. We applied our approach to blood pressure phenotypes in the UK Biobank data (N = 360,243), the results of which we report here. We confirm and further refine several associations with multiple processes involved in heart and blood vessel formation but also identify novel interactions, among others with cardiovascular tissues involved in regulatory pathways of blood pressure homoeostasis.

Gene-set analysis (GSA) is widely used to infer functional and biological properties of a gene set. Here, the authors develop a conditional and interaction gene-set analysis approach that can considerably refine results from traditional GSA.

No detectable differential microRNA expression between non-atherosclerotic arteries of type 2 diabetic patients (treated or untreated with metformin) and non-diabetic patients

Background

Type 2 diabetes mellitus (T2DM) is an independent risk factor of cardiovascular disease (CVD), however, the underlying mechanisms are largely unknown. Using non-atherosclerotic internal thoracic arteries (ITAs) obtained from coronary artery bypass grafting, we previously identified a distinct elevation in the level of proteins comprising the arterial basement membrane in T2DM patients not treated with metformin. Altered transcription of genes encoding these proteins has not been observed, indicating alternative mechanisms of dysregulation.

Methods

In this study we screened for differential expression of arterial microRNAs (miRNAs) in T2DM patients to test the hypothesis that the arterial protein signature of diabetic patients is associated with dysregulation at the miRNA level, and further to lay the foundation for novel hypotheses addressing the increased CVD risk of T2DM patients. MiRNA isolated from fresh frozen ITAs [from 18 T2DM- (10 of which were subject to metformin treatment) and 30 non-diabetes mellitus (non-DM) patients] were analyzed by microarray, and miRNAs isolated from formalin-fixated paraffin-embedded (FFPE) ITAs were analyzed by quantitative PCR (qPCR) in an independent study group [26 T2DM- (15 of which were subject to metformin treatment) and 26 non-DM patients] to determine expression levels of miRNAs in a pre-defined panel of 12 miRNAs.

Results

Unexpectedly, no miRNAs were found to be affected by T2DM status in either of the two study groups.

Conclusions

Our data suggest that alternatives to microRNA dysregulation underlie T2DM-associated protein changes in non-atherosclerotic arteries.

Electronic supplementary material

The online version of this article (10.1186/s12933-018-0715-y) contains supplementary material, which is available to authorized users.

Krüppel-Like Factors in Vascular Inflammation: Mechanistic Insights and Therapeutic Potential

The role of inflammation in vascular disease is well recognized, involving dysregulation of both circulating immune cells as well as the cells of the vessel wall itself. Unrestrained vascular inflammation leads to pathological remodeling that eventually contributes to atherothrombotic disease and its associated sequelae (e.g., myocardial/cerebral infarction, embolism, and critical limb ischemia). Signaling events during vascular inflammation orchestrate widespread transcriptional programs that affect the functions of vascular and circulating inflammatory cells. The Krüppel-like factors (KLFs) are a family of transcription factors central in regulating vascular biology in states of homeostasis and disease. Given their abundance and diversity of function in cells associated with vascular inflammation, understanding the transcriptional networks regulated by KLFs will further our understanding of the pathogenesis underlying several pervasive health concerns (e.g., atherosclerosis, stroke, etc.) and consequently inform the treatment of cardiovascular disease. Within this review, we will discuss the role of KLFs in coordinating protective and deleterious responses during vascular inflammation, while addressing the potential targeting of these critical transcription factors in future therapies.

Loss of Vascular Myogenic Tone in miR-143/145 Knockout Mice Is Associated With Hypertension-Induced Vascular Lesions in Small Mesenteric Arteries

OBJECTIVE

Pressure-induced myogenic tone is involved in autoregulation of local blood flow and confers protection against excessive pressure levels in small arteries and capillaries. Myogenic tone is dependent on smooth muscle microRNAs (miRNAs), but the identity of these miRNAs is unclear. Furthermore, the consequences of altered myogenic tone for hypertension-induced damage to small arteries are not well understood.

APPROACH AND RESULTS

The importance of smooth muscle-enriched microRNAs, miR-143/145, for myogenic tone was evaluated in miR-143/145 knockout mice. Furthermore, hypertension-induced vascular injury was evaluated in mesenteric arteries in vivo after angiotensin II infusion. Myogenic tone was abolished in miR-143/145 knockout mesenteric arteries, whereas contraction in response to calyculin A and potassium chloride was reduced by ≈30%. Furthermore, myogenic responsiveness was potentiated by angiotensin II in wild-type but not in knockout mice. Angiotensin II administration in vivo elevated systemic blood pressure in both genotypes. Hypertensive knockout mice developed severe vascular lesions characterized by vascular inflammation, adventitial fibrosis, and neointimal hyperplasia in small mesenteric arteries. This was associated with depolymerization of actin filaments and fragmentation of the elastic laminae at the sites of vascular lesions.

CONCLUSIONS

This study demonstrates that miR-143/145 expression is essential for myogenic responsiveness. During hypertension, loss of myogenic tone results in potentially damaging levels of mechanical stress and detrimental effects on small arteries. The results presented herein provide novel insights into the pathogenesis of vascular disease and emphasize the importance of controlling mechanical factors to maintain structural integrity of the vascular wall.

Effect of miR-29b on the Proliferation and Apoptosis of Pulmonary Artery Smooth Muscle Cells by Targeting Mcl-1 and CCND2

The proliferation and apoptosis of pulmonary artery smooth muscle cells (PASMCs) are considered to be key steps in the progression of pulmonary arterial hypertension (PAH). MicroRNAs (e.g., miR-29b) have been identified in various diseases to be critical modulators of cell growth and apoptosis by targeting Mcl-1 and CCND2. However, the role of miR-29b in PAH remains unknown. So we try to investigate the effect of miR-29b on Mcl-1 and CCND2 protein in PASMCs, analyze the effect of miR-29b on the proliferation of PASMCs, and explore the significance of miR-29b in the proliferation, apoptosis, and gene therapy of PAH. It was observed that gene chip analysis showed miR-29b expression in pulmonary artery tissue. The expression of miR-29b was significantly reduced in PAH model mice. MiR-29b inhibited the proliferation of PASMCs and promoted the apoptosis of PASMCs. Mechanically, miR-29b could inhibit the expression of Mcl-1 and CCND2 protein and silenced Mcl-1 and CCND2 could abolish the change of proliferation and apoptosis of PASMCs. These results demonstrate that miR-29b suppressed cellular proliferation and promoted apoptosis of PASMCs, possibly through the inhibition of Mcl-1 and CCND2. Therefore, miR-29b may serve as a useful therapeutic tool to treat PAH.

Apelin/APJ system: A critical regulator of vascular smooth muscle cell

APJ, an orphan G protein-coupled receptor, is first identified through homology cloning in 1993. Apelin is endogenous ligand of APJ extracted from bovine stomach tissue in 1998. Apelin/APJ system is widely expressed in many kinds of cells such as endothelial cells, cardiomyocytes, especially vascular smooth muscle cell. Vascular smooth muscle cell (VSMC), an integral part of the vascular wall, takes part in many normal physiological processes. Our experiment firstly finds that apelin/APJ system enhances VSMC proliferation by ERK1/2-cyclin D1 signal pathway. Accumulating studies also show that apelin/APJ system plays a pivotal role in mediating the function of VSMC. In this paper, we review the exact role of apelin/APJ system in VSMC, including induction of proliferation and migration, enhance of contraction and relaxation, inhibition of calcification. Furthermore, we discuss the role of apelin/APJ system in vascular diseases, such as atherosclerosis, hypertension, and chronic kidney disease (CKD) from the point of VSMC. Above all, apelin/APJ system is a promising target for managing vascular disease.

Thrombosis and Vascular Inflammation in Diabetes: Mechanisms and Potential Therapeutic Targets

Cardiovascular disease remains the main cause of morbidity and mortality in patients with diabetes. The risk of vascular ischemia is increased in this population and outcome following an event is inferior compared to individuals with normal glucose metabolism. The reasons for the adverse vascular profile in diabetes are related to a combination of more extensive atherosclerotic disease coupled with an enhanced thrombotic environment. Long-term measures to halt the accelerated atherosclerotic process in diabetes have only partially addressed vascular pathology, while long-term antithrombotic management remains largely similar to individuals without diabetes. We address in this review the pathophysiological mechanisms responsible for atherosclerosis with special emphasis on diabetes-related pathways. We also cover the enhanced thrombotic milieu, characterized by increased platelet activation, raised activity of procoagulant proteins together with compromised function of the fibrinolytic system. Potential new therapeutic targets to reduce the risk of atherothrombosis in diabetes are explored, including alternative use of existing therapies. Special emphasis is placed on diabetes-specific therapeutic targets that have the potential to reduce vascular risk while keeping an acceptable clinical side effect profile. It is now generally acknowledged that diabetes is not a single clinical entity but a continuum of various stages of the condition with each having a different vascular risk. Therefore, we propose that future therapies aiming to reduce vascular risk in diabetes require a stratified approach with each group having a "stage-specific" vascular management strategy. This "individualized care" in diabetes may prove to be essential to improve vascular outcome in this high risk population.

The Aging Risk and Atherosclerosis: A Fresh Look at Arterial Homeostasis

A considerable volume of research over the last decade has focused on understanding the fundamental mechanisms for the progression of atherosclerosis-the underlying cause for the vast majority of all cardiovascular (CVD)-related complications. Aging is the dominant risk factor for clinically significant atherosclerotic lesion formation, yet the heightened impact of aging on the disease is not accounted for by changes in traditional risk factors, such as lack of physical activity, smoking, hypertension, hyperlipidemia, or diabetes mellitus. This review will examine the pathological and biochemical processes of atherosclerotic plaque formation and growth, with particular focus on the aging risk vis-a-vis arterial homeostasis. Particular focus will be placed on the impact of a number of important contributors to arterial homeostasis including bone marrow (BM)-derived vascular progenitor cells, differential monocyte subpopulations, and the role of cellular senescence. Finally, this review will explore many critical observations in the way the disease process has been reassessed both by clinicians and researchers, and will highlight recent advances in this field that have provided a greater understanding of this aging-driven disease.

The Role of MicroRNAs in Arterial Stiffness and Arterial Calcification. An Update and Review of the Literature

Arterial stiffness is an independent risk factor for fatal and non-fatal cardiovascular events, such as systolic hypertension, coronary artery disease, stroke, and heart failure. Moreover it reflects arterial aging which in many cases does not coincide with chronological aging, a fact that is in large attributed to genetic factors. In addition to genetic factors, microRNAs (miRNAs) seem to largely affect arterial aging either by advancing or by regressing arterial stiffness. MiRNAs are small RNA molecules, ~22 nucleotides long that can negatively control their target gene expression posttranscriptionally. Pathways that affect main components of stiffness such as fibrosis and calcification seem to be influenced by up or downregulation of specific miRNAs. Identification of this aberrant production of miRNAs can help identify epigenetic changes that can be therapeutic targets for prevention and treatment of vascular diseases. The present review summarizes the specific role of the so far discovered miRNAs that are involved in pathways of arterial stiffness.

ABCA1 and HDL3 are required to modulate smooth muscle cells phenotypic switch after cholesterol loading

BACKGROUND AND AIMS

Cholesterol-loaded smooth muscle cells (SMCs) modify their phenotypic behavior becoming foam cells. To characterize the role of ABCA1 and HDL3 in this process, we evaluated HDL3 effects on cholesterol-induced phenotypic changes in SMCs expressing or not ABCA1.

METHODS

SMCs, isolated from the aortae of wild-type (WT) and Abca1 knock-out (KO) mice, were cholesterol-loaded using a "water-soluble cholesterol''.

RESULTS

Cholesterol loading downregulates the expression of Acta2 and calponin (SMC markers), and increases the expression of Mac-2, CD11b and MHCII (inflammation-related genes and surface antigens) and Abca1, Abcg1. HDL3 normalizes SMC marker expression and reduces the expression of inflammation-related genes/proteins in WT cells, an effect not observed with free apoA-I. The effect of HDL3 is almost lost in Abca1 KO cells, as well as when Abca1 is silenced in WT SMC. HDL3 does not differently affect cholesterol downloading in WT or KO cells and stimulates phospholipids removal in WT cells. Similarly, the expression of myocardin and its modulators, such as miR-143/145, is reduced by cholesterol loading in WT and Abca1 KO SMCs; HDL3 normalizes their levels in WT cells but not in KO cells. On the contrary, cholesterol loading induces Klf4 expression while HDL3 restores Klf4 to basal levels in WT cells, but again this effect is not observed in KO cells.

CONCLUSIONS

Our results indicate that HDL3, by interacting with ABCA1, modulates the miR143/145-myocardin axis and prevents the cholesterol-induced gene expression modification in SMCs regardless of its cholesterol unloading capacity.

miRNA-145 is associated with spontaneous hypertension by targeting SLC7A1

Previous studies have indicated that microRNAs (miRNAs/miRs) may participate in the pathogenesis of hypertension. miR-145 has been demonstrated to serve important roles in the development of numerous cardiovascular diseases. However, the specific role of miR-145 in hypertension remains unclear. The present study aimed to investigate the role of miR-145 in spontaneously hypertensive rats (SHR) and rat vascular endothelial cells (RVECs). The results of the present study demonstrated that in the SHR group miR-145 expression was significantly upregulated in the thoracic aorta compared with the control group. Furthermore, a significant decrease in nitric oxide (NO) content was observed in the SHR group compared with the control rats. In RVECs, silencing miR-145 induced a significant increase in the expression of solute carrier family 7 member 1 (SLC7A1) and phosphorylated endothelial nitric oxide synthase, and a dual-luciferase reporter assay confirmed that SLC7A1 is a direct target of miR-145. The results of the present study indicate that miR-145 functions as a key mediator in the pathogenesis of hypertension via targeting SLC7A1, which suggests that miR-145 is a potential target for the treatment of hypertension.

MiR-362-3p inhibits the proliferation and migration of vascular smooth muscle cells in atherosclerosis by targeting ADAMTS1

Atherosclerosis is a progressive condition of the large arteries that can cause coronary artery disease (CAD). Growing amounts of evidence have indicated that microRNAs (miRNAs, miRs) can be used as diagnostic biomarkers in many cellular processes associated with CAD. MiR-362-3p has been implicated in many biological cellular functions. However, little is known about the role of miR-362-3p during atherosclerosis. In the present study, significant downregulation of miR-362-3p was observed in 110 atherosclerotic CAD patients and not in the 84 controls. The upregulation of miR-362-3p was demonstrated to inhibit vascular smooth muscle cell (VSMC) proliferation and migration, and impede the G1/S cell cycle transition. Bioinformatics analysis indicated that a disintegrin and metalloproteinase with thrombospondin motifs 1 (ADAMTS1) was a direct target of miR-362-3p. Subsequent experiments demonstrated that miR-362-3p binds to the 3'-untranslated region (UTR) of ADAMTS1 and decreases its levels of mRNA and protein expression. Overexpression of ADAMTS1 partially restored the miR-362-3p-mediated inhibition of VSMC proliferation, cell cycle, and migration. Upregulation of ADAMTS1 in plasma samples was detected in atherosclerotic CAD patients. Taken together, our findings suggested that miR-362-3p inhibits the proliferation and migration of VSMCs by directly targeting ADAMTS1, which might provide novel insight into the molecular mechanisms underlying the action of miR-362-3p in atherosclerosis.

Exosome-Mediated miR-155 Transfer from Smooth Muscle Cells to Endothelial Cells Induces Endothelial Injury and Promotes Atherosclerosis

The vascular response to pro-atherosclerotic factors is a multifactorial process involving endothelial cells (ECs), macrophages (MACs), and smooth muscle cells (SMCs), although the mechanism by which these cell types communicate with each other in response to environmental cues is yet to be understood. Here, we show that miR-155, which is significantly expressed and secreted in Krüppel-like factor 5 (KLF5)-overexpressing vascular smooth muscle cells (VSMCs), is a potent regulator of endothelium barrier function through regulating endothelial targeting tight junction protein expression. VSMCs-derived exosomes mediate the transfer of KLF5-induced miR-155 from SMCs to ECs, which, in turn, destroys tight junctions and the integrity of endothelial barriers, leading to an increased endothelial permeability and enhanced atherosclerotic progression. Moreover, overexpression of miR-155 in ECs inhibits endothelial cell proliferation/migration and re-endothelialization in vitro and in vivo and thus increases vascular endothelial permeability. Blockage of the exosome-mediated transfer of miR-155 between these two cells may serve as a therapeutic target for atherosclerosis.

Functional electrospun fibrous scaffolds with dextran-g-poly(l-lysine)-VAPG/microRNA-145 to specially modulate vascular SMCs

Functional electrospun membranes loaded with Dex-g-PLL-VAPG/miR-145 complexes exhibit the excellent ability to modulate SMC phenotype and proliferation locally.

Influence of periostin-positive cell-specific Klf5 deletion on aortic thickening in DOCA-salt hypertensive mice

Chronic hypertension causes vascular remodeling that is associated with an increase in periostin- (postn) positive cells, including fibroblasts and smooth muscle cells. Krüppel-like factor (KLF) 5, a transcription factor, is also observed in vascular remodeling; however, it is unknown what role KLF5 plays in postn-positive cells during vascular remodeling induced by deoxycorticosterone-acetate (DOCA) salt. We used postn-positive cell-specific Klf5-deficient mice (Klf5^PostnKO: Klf5^flox/flox; Postn^Cre/-) and wild-type mice (WT: Klf5^flox/flox; Postn^-/-). We implanted a DOCA pellet and provided drinking water containing 0.9% NaCl for 8 weeks. The DOCA-salt treatment induced hypertension in both genotypes, as observed by increases in systolic blood pressure. In WT animals, DOCA-salt treatment increased the aortic medial area compared with the non-treated controls. Similarly, Tgfb1 was overexpressed in the aortas of the DOCA-salt treated WT mice compared with the controls. Immunofluorescence staining revealed that fibroblast-specific protein 1 (FSP1)⁺-α smooth muscle actin (αSMA)⁺ myofibroblasts exist in the medial area of the WT aortas after DOCA-salt intervention. Importantly, these changes were not observed in the Klf5^PostnKO animals. In conclusion, the results of this study suggest that the presence of KLF5 in postn-positive cells contributes to the pathogenesis of aortic thickening induced by DOCA-salt hypertension.