miR-15b induced by platelet-derived growth factor signaling is required for vascular smooth muscle cell proliferation

SPINT2 is involved in the proliferation, migration and phenotypic switching of aortic smooth muscle cells: Implications for the pathogenesis of thoracic aortic dissection

Thoracic aortic dissection (TAD) is a severe and extremely dangerous cardiovascular disease. Proliferation, migration and phenotypic switching of vascular smooth muscle cells (SMCs) are major pathogenetic mechanisms involved in the development of TAD. The present study was designed to investigate the expression and potential function of serine peptidase inhibitor Kunitz type 2 (SPINT2) in TAD. The gene expression profile data for ascending aorta from patients with TAD were downloaded from the GEO database with the accession number GSE52093. Bioinformatics analysis using GEO2R indicated that the differentially expressed SPINT2 was prominently decreased in TAD. The expression levels of SPINT2 mRNA and protein in aortic dissection specimens and normal aorta tissues were measured using reverse transcription-quantitative PCR and western blotting. SPINT2 expression was downregulated in clinical samples from aortic dissection specimens of patients with TAD compared with the corresponding expression noted in tissues derived from patients without TAD. In vitro, platelet-derived growth factor BB (PDGF-BB) was applied to induce the isolated primary mouse aortic SMC phenotypic modulation (a significant upregulation in the expression levels of synthetic markers), and the SMCs were infected with the adenoviral vector, Ad-SPINT2, to construct SPINT2-overexpressed cell lines. SMC viability was detected by an MTT assay and SMC proliferation was detected via the presence of Ki-67-positive cells (immunofluorescence staining). To explore the effects of SPINT2 on SMC migration, a wound healing assay was conducted. ELISA and western blotting assays were used to measure the content and expression levels of MMP-2 and MMP-9. The expression levels of vimentin, collagen I, α-SMA and SM22α were measured using western blotting. The PDGF-BB-induced proliferation and migration of SMCs were recovered by SPINT2 overexpression. The increase in the expression levels of SPINT2 reduced the expression levels of active matrix metalloproteinases (MMPs), MMP-2 and MMP-9. Overexpression of SPINT2 suppressed SMC switching from a contractile to a synthetic type, as evidenced by decreased vimentin and collagen I expression levels along with increased α-smooth muscle actin and smooth muscle protein 22-α expression levels. Furthermore, activation of ERK was inhibited in SPINT2-overexpressing SMCs. A specific ERK agonist, 12-O-tetradecanoylphorbol-13-acetate, reversed the SPINT2-mediated inhibition of SMC migration and the phenotypic switching. Collectively, the data indicated that SPINT2 was implicated in the proliferation, migration and phenotypic switching of aortic SMCs, suggesting that it may be involved in TAD progression.

Modulation of Smooth Muscle Cell Phenotype for Translation of Tissue-Engineered Vascular Grafts

Translation of small-diameter tissue-engineered vascular grafts (TEVGs) for the treatment of coronary artery disease (CAD) remains an unfulfilled promise. This is largely due to the limited integration of TEVGs into the native vascular wall-a process hampered by the insufficient smooth muscle cell (SMC) infiltration and extracellular matrix deposition, and low vasoactivity. These processes can be promoted through the judicious modulation of the SMC toward a synthetic phenotype to promote remodeling and vascular integration; however, the expression of synthetic markers is often accompanied by a decrease in the expression of contractile proteins. Therefore, techniques that can precisely modulate the SMC phenotypical behavior could have the potential to advance the translation of TEVGs. In this review, we describe the phenotypic diversity of SMCs and the different environmental cues that allow the modulation of SMC gene expression. Furthermore, we describe the emerging biomaterial approaches to modulate the SMC phenotype in TEVG design and discuss the limitations of current techniques. In addition, we found that current studies in tissue engineering limit the analysis of the SMC phenotype to a few markers, which are often the characteristic of early differentiation only. This limited scope has reduced the potential of tissue engineering to modulate the SMC toward specific behaviors and applications. Therefore, we recommend using the techniques presented in this review, in addition to modern single-cell proteomics analysis techniques to comprehensively characterize the phenotypic modulation of SMCs. Expanding the holistic potential of SMC modulation presents a great opportunity to advance the translation of living conduits for CAD therapeutics.

MicroRNA regulation of phenotypic transformations in vascular smooth muscle: relevance to vascular remodeling

Alterations in the vascular smooth muscle cells (VSMC) phenotype play a critical role in the pathogenesis of several cardiovascular diseases, including hypertension, atherosclerosis, and restenosis after angioplasty. MicroRNAs (miRNAs) are a class of endogenous noncoding RNAs (approximately 19-25 nucleotides in length) that function as regulators in various physiological and pathophysiological events. Recent studies have suggested that aberrant miRNAs' expression might underlie VSMC phenotypic transformation, appearing to regulate the phenotypic transformations of VSMCs by targeting specific genes that either participate in the maintenance of the contractile phenotype or contribute to the transformation to alternate phenotypes, and affecting atherosclerosis, hypertension, and coronary artery disease by altering VSMC proliferation, migration, differentiation, inflammation, calcification, oxidative stress, and apoptosis, suggesting an important regulatory role in vascular remodeling for maintaining vascular homeostasis. This review outlines recent progress in the discovery of miRNAs and elucidation of their mechanisms of action and functions in VSMC phenotypic regulation. Importantly, as the literature supports roles for miRNAs in modulating vascular remodeling and for maintaining vascular homeostasis, this area of research will likely provide new insights into clinical diagnosis and prognosis and ultimately facilitate the identification of novel therapeutic targets.

Emerging Roles of Circular RNAs in Vascular Smooth Muscle Cell Dysfunction

Atherosclerosis is the major pathophysiological basis of cerebrovascular and cardiovascular diseases. Vascular smooth muscle cells (VSMCs) constitute the main structure of vasculature and play important roles in maintaining vascular tone and blood pressure. Many biological processes and cellular signaling events involved in atherosclerogenesis have been shown to converge on deregulating VSMC functions. However, the molecular mechanisms underlying dysfunctional VSMC in atherosclerosis are still poorly defined. Recent evidence revealed that circular RNAs (circRNAs) are closely related to diseases such as degenerative diseases, tumor, congenital diseases, endocrine diseases and cardiovascular diseases. Several studies demonstrated that circRNAs (e.g., circACTA2, Circ-SATB2, circDiaph3, circ_0020397, circTET3, circCCDC66) played critical roles in the regulation of VSMC proliferation, migration, invasion, and contractile-to-synthetic phenotype transformation by sponging microRNAs (e.g., miR-548f-5p, miR-939, miR-148a-5p, miR-138, miR-351-5p, miR-342-3p). This review describes recent progress in the profiling of circRNAs by transcriptome analysis in VSMCs and their molecular functions in regulating VSMC proliferation and migration.

An Overview of miRNAs Involved in PASMC Phenotypic Switching in Pulmonary Hypertension

Pulmonary hypertension (PH) is occult, with no distinctive clinical manifestations and a poor prognosis. Pulmonary vascular remodelling is an important pathological feature in which pulmonary artery smooth muscle cells (PASMCs) phenotypic switching plays a crucial role. MicroRNAs (miRNAs) are a class of evolutionarily highly conserved single-stranded small noncoding RNAs. An increasing number of studies have shown that miRNAs play an important role in the occurrence and development of PH by regulating PASMCs phenotypic switching, which is expected to be a potential target for the prevention and treatment of PH. miRNAs such as miR-221, miR-15b, miR-96, miR-24, miR-23a, miR-9, miR-214, and miR-20a can promote PASMCs phenotypic switching, while such as miR-21, miR-132, miR-449, miR-206, miR-124, miR-30c, miR-140, and the miR-17~92 cluster can inhibit it. The article reviews the research progress on growth factor-related miRNAs and hypoxia-related miRNAs that mediate PASMCs phenotypic switching in PH.

A Novel COX10 Deletion Polymorphism as a Susceptibility Factor for Sudden Cardiac Death Risk in Chinese Populations

Identifying common genetic variations that are related to sudden cardiac death (SCD) is crucial since it can facilitate the diagnosis and risk stratification of SCD. It has been reported that COX10 mutations might be related with SCD. In this study, we performed a systematic variant screening on the COX10 to filter potential functional genetic variations. Based on the screening results, an insertion/deletion polymorphism (rs397763766) in 3'untranslated regions of COX10 was selected as the candidate variant. We conducted a case-control study to investigate the association between rs397763766 and SCD susceptibility in Chinese populations. Logistic regression analysis showed that the deletion allele of rs397763766 was associated with an increased risk for SCD (odds ratio = 1.61, 95% confidence interval = 1.25-2.07, p = 1.87 × 10^-4) susceptibility than insertion allele. Further genotype-phenotype analysis using human cardiac tissue samples suggested that COX10 expression level in genotypes containing deletion allele was higher than that in ins/ins genotype. The results were further reinforced by RNA sequencing data from 1000 Genomes Project. Luciferase activity assay indicated that COX10 expression could be regulated by rs397763766 through interfering binding with miR-15b, thus conferring risk of SCD. In conclusion, the novel rs397763766 polymorphism might be a potential marker for molecular diagnosis and genetic counseling of SCD.

miRNA Profiling of Circulating Small Extracellular Vesicles From Subarachnoid Hemorrhage Rats Using Next-Generation Sequencing

Background

Extracellular vesicles (EVs) are produced during abnormal and normal physiological conditions. Understanding the expression profile of microRNA (miRNA) in plasma-derived small extracellular vesicles (sEVs) and their roles in subarachnoid hemorrhage (SAH) that cause cerebral vasospasm (CVS) is imperative.

Methods

Sprague Dawley rats (250–300 g) were allocated to sham or SAH groups established using endovascular perforation method. miRNA expression profiles of plasma sEVs in both groups (each n = 4) were evaluated using next-generation sequencing (NGS).

Results

There were 142 microRNAs (miRNAs) significantly expressed differently between the two groups, of which 73 were up-regulated while 69 were down-regulated in SAH sEVs compared with those of sham (p < 0.05; fold change ≥ 2). The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) analyses of differently expressed (DE) miRNAs revealed signaling pathways and target genes (TGs) in the SAH group. rno-miR-185-5p, rno-miR-103-3p, rno-miR-15b-3p, rno-miR-93-5p, and rno-miR-98-5p were the top five most up-regulated sEVs miRNAs.

Conclusion

Our results suggest that miRNA can be selectively packaged into sEVs under SAH, and this could help develop potential targets for the prevention, diagnosis, and treatment of CVS after this condition.

MicroRNA 322 Aggravates Dexamethasone-Induced Muscle Atrophy by Targeting IGF1R and INSR

Dexamethasone (Dex) has been widely used as a potent anti-inflammatory, antishock, and immunosuppressive agent. However, high dose or long-term use of Dex is accompanied by side effects including skeletal muscle atrophy, whose underlying mechanisms remain incompletely understood. A number of microRNAs (miRNAs) have been shown to play key roles in skeletal muscle atrophy. Previous studies showed significantly increased miR-322 expression in Dex-treated C2C12 myotubes. In our study, the glucocorticoid receptor (GR) was required for Dex to increase miR-322 expression in C2C12 myotubes. miR-322 mimic or miR-322 inhibitor was used for regulating the expression of miR-322. Insulin-like growth factor 1 receptor (IGF1R) and insulin receptor (INSR) were identified as target genes of miR-322 using luciferase reporter assays and played key roles in Dex-induced muscle atrophy. miR-322 overexpression promoted atrophy in Dex-treated C2C12 myotubes and the gastrocnemius muscles of mice. Conversely, miR-322 inhibition showed the opposite effects. These data suggested that miR-322 contributes to Dex-induced muscle atrophy via targeting of IGF1R and INSR. Furthermore, miR-322 might be a potential target to counter Dex-induced muscle atrophy. miR-322 inhibition might also represent a therapeutic approach for Dex-induced muscle atrophy.

Long noncoding RNA LINC00968 promotes endothelial cell proliferation and migration via regulating miR-9-3p expression

Long noncoding RNAs (lncRNAs) have been showed to play a crucial role in pathogenesis and development of cardiovascular diseases. Our study aimed to study the expression and functional role of lncRNA LINC00968 in the development of coronary artery disease (CAD). We showed that the LINC00968 expression level was upregulated in the CAD tissues compared with normal arterial tissues. In addition, we showed that the expression level of LINC00968 was upregulated by oxidized low-density lipoprotein (oxLDL) treatment in endothelial cell. Ectopic expression of LINC00968 regulated the proliferation and migration of endothelial cell. Moreover, we showed that overexpression of LINC00968 inhibited miR-9-3p expression in an endothelial cell. Furthermore, we demonstrated that the miR-9-3p expression was downregulated in the CAD samples compared with normal arterial tissues and the expression level of miR-9-3p was downregulated by oxLDL treatment in endothelial cell. Finally, we showed that ectopic expression of LINC00968 promoted endothelial cell proliferation and migration partly through regulating miR-9-3p expression. These results suggested that LINC00968 plays a crucial role in the progression of the CAD.

MiR-147b influences vascular smooth muscle cell proliferation and migration via targeting YY1 and modulating Wnt/β-catenin activities

Cardiovascular disease is the leading cause of death worldwide. Dysregulation of microRNAs (miRNAs) has been found to be associated with cardiovascular diseases such as atherosclerosis. In the present study, we examined the role of miR-147b in the proliferation and migration of vascular smooth muscle cells (VSMCs). Quantitative real-time PCR was performed to determine the expression levels of miR-147b and Yin Yang 1 (YY1) mRNA. CCK-8, transwell migration and wound healing assays were used to determine cell proliferation and migration of VSMCs, respectively. Luciferase reporter assay confirmed the downstream target of miR-147b. The protein level of YY1 was measured by western blot analysis. Platelet-derived growth factor-bb (PDGF-bb) treatment promoted cell proliferation and increased miR-147b expression in VSMCs. Overexpression of miR-147b enhanced cell proliferation and migration of VSMCs, while knock-down of miR-147b suppressed cell proliferation and migration of VSMCs or PDGF-bb-treated VSMCs. Further, bioinformatics prediction and luciferase reporter assay showed that YY1 was a downstream target of miR-147b, and miR-147b negatively regulated the mRNA and protein expression of YY1 in VSMCs. Overexpression of YY1 inhibited cell proliferation and migration of VSMCs and attenuated the effects of miR-147b overexpression on cell proliferation and migration. In addition, overexpression of miR-147b increased the Wnt/β-catenin signaling activities in VSMCs. In conclusion, our results suggest that miR-147b plays important roles in the control of cell proliferation and migration of VSMCs possibly via targeting YY1.

miR-22 Is a Novel Mediator of Vascular Smooth Muscle Cell Phenotypic Modulation and Neointima Formation

Supplemental Digital Content is available in the text.

Background:

MicroRNA-22 (miR-22) has recently been reported to play a regulatory role during vascular smooth muscle cell (VSMC) differentiation from stem cells, but little is known about its target genes and related pathways in mature VSMC phenotypic modulation or its clinical implication in neointima formation following vascular injury.

Methods:

We applied a wire-injury mouse model, and local delivery of AgomiR-22 or miR-22 inhibitor, as well, to explore the therapeutic potential of miR-22 in vascular diseases. Furthermore, normal and diseased human femoral arteries were harvested, and various in vivo, ex vivo, and in vitro models of VSMC phenotype switching were conducted to examine miR-22 expression during VSMC phenotype switching.

Results:

Expression of miR-22 was closely regulated during VSMC phenotypic modulation. miR-22 overexpression significantly increased expression of VSMC marker genes and inhibited VSMC proliferation and migration, whereas the opposite effect was observed when endogenous miR-22 was knocked down. As expected, 2 previously reported miR-22 target genes, MECP2 (methyl-CpG binding protein 2) and histone deacetylase 4, exhibited a regulatory role in VSMC phenotypic modulation. A transcriptional regulator and oncoprotein, EVI1 (ecotropic virus integration site 1 protein homolog), has been identified as a novel miR-22 target gene in VSMC phenotypic modulation. It is noteworthy that overexpression of miR-22 in the injured vessels significantly reduced the expression of its target genes, decreased VSMC proliferation, and inhibited neointima formation in wire-injured femoral arteries, whereas the opposite effect was observed with local application of a miR-22 inhibitor to injured arteries. We next examined the clinical relevance of miR-22 expression and its target genes in human femoral arteries. We found that miR-22 expression was significantly reduced, whereas MECP2 and EVI1 expression levels were dramatically increased, in diseased in comparison with healthy femoral human arteries. This inverse relationship between miR-22 and MECP2 and EVI1 was evident in both healthy and diseased human femoral arteries.

Conclusions:

Our data demonstrate that miR-22 and EVI1 are novel regulators of VSMC function, specifically during neointima hyperplasia, offering a novel therapeutic opportunity for treating vascular diseases.

microRNA-612 is downregulated by platelet-derived growth factor-BB treatment and has inhibitory effects on vascular smooth muscle cell proliferation and migration via directly targeting AKT2

Abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) has been implicated in neointimal formation, and therefore is suggested to contribute to arteriosclerosis and restenosis. Previous studies have suggested that some microRNAs (miRs) serve crucial roles in VSMC proliferation and invasion; however, the underlying mechanism remains largely unknown. In the present study, it was demonstrated that treatment with platelet-derived growth factor (PDGF)-BB significantly promoted the proliferation and migration of VSMCs, and decreased miR-612 levels in VSMCs. Overexpression of miR-612 significantly inhibited PDGF-BB-induced migration and invasion of VSMCs, through inducing cell cycle arrest at G1 stage. AKT2 was further identified as a direct target gene of miR-612, and its expression was negatively regulated by miR-612 in VSMCs. Further investigation confirmed that overexpression of miR-612 suppressed the PDGF-BB-induced upregulation of AKT2 protein expression. In conclusion, the present study demonstrated that miR-612 is downregulated by PDGF-BB treatment and has inhibitory effects on VSMC proliferation and migration via targeting AKT2. These findings suggest that miR-612 may be used as a potential therapeutic candidate for neointimal formation in patients with atherosclerosis.

MiR-137 inhibited cell proliferation and migration of vascular smooth muscle cells via targeting IGFBP-5 and modulating the mTOR/STAT3 signaling

Abnormal proliferation of vascular smooth muscle cells (VSMCs) contributes to the development of cardiovascular diseases. Studies have shown the great impact of microRNAs (miRNAs) on the cell proliferation of VSMCs. This study examined the effects of miR-137 on the cell proliferation and migration of VSMCs and also explored the underlying molecular mechanisms. The mRNA and protein expression levels were determined by qRT-PCR and western blot assays, respectively. The CCK-8 assay, wound healing assay and transwell migration assay were performed to measure cell proliferation and migration of VSMCs. The miR-137-targeted 3’untranslated region of insulin-like growth factor-binding protein-5 (IGFBP-5) was confirmed by luciferase reporter assay. Platelet-derived growth factor-bb (PDGF-bb) treatment enhanced cell proliferation and suppressed the expression of miR-137 in VSMCs. The gain-of-function and loss-of-function assays showed that overexpression of miR-137 suppressed the cell proliferation and migration, and also inhibited the expression of matrix genes of VSMCs; down-regulation of miR-137 had the opposite effects on VSMCs. Bioinformatics analysis and luciferase report assay results showed that IGFBP-5 was a direct target of miR-137, and miR-137 overexpression suppressed the IGFBP-5 expression and down-regulation of miR-137 increased the IGFBP-5 expression in VSMCs. PDGF-bb treatment also increased the IGFBP-5 mRNA expression. In addition, enforced expression of IGFBP-5 reversed the inhibitory effects of miR-137 on cell proliferation and migration of VSMCs. More importantly, overexpression of miR-137 also suppressed the activity of mTOR/STAT3 signaling in VSMCs. Taken together, the results suggest that miR-137 may suppress cell proliferation and migration of VSMCs via targeting IGFBP-5 and modulating mTOR/STAT3 signaling pathway.

LncRNA BANCR facilitates vascular smooth muscle cell proliferation and migration through JNK pathway

Deregulated migration and proliferation of vascular smooth muscle cells (VSMCs) acts a crucial role in the pathogenesis of many cardiovascular diseases such as atherosclerosis, coronary heart disease and hypertension. Long noncoding RNAs (lncRNAs) play crucial functional roles in a lot of biological processes such as cell development, cell proliferation, differentiation and invasion. In our study, we demonstrated that the BANCR expression level was upregulated in the atherosclerotic plaques tissues compared to in the normal vessels tissues. TNF-α could emhance the VSMCs proliferation. The expression level of BANCR and p-JNK were upregulated and activated in the proliferating VSMCs. Overexpression of BANCR enhanced VSMCs proliferation and migration. Elevated expression of BANCR induced JNK activation, which can be decreased by the specific JNK inhibitor SP600125. We demonstrated that ectopic expression of BANCR increased the VSMCs proliferation and migration through activating JNK pathway. These data suggested that lncRNA BANCR acts a crucial role in the regulating VSMCs proliferation and migration partly by activating the JNK pathway.

MiR-448 promotes vascular smooth muscle cell proliferation and migration in through directly targeting MEF2C

Abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) is a critical process in various cardiovascular diseases such as coronary artery disease (CAD), atherosclerosis, stroke, and hypertension. MicroRNAs (miRNAs) are small, short, and noncoding RNAs that inhibit gene expression through binding to the 3'-UTR (3' untranslated regions) of target gene mRNAs. We showed that the expression of miR-448 was upregulated in VSMCs from coronary atherosclerotic plaques compared with normal coronary artery tissues. We also found that PDGF-bb promoted VSMCs proliferation and could induce miR-448 expression. Ectopic miR-448 expression induced VSMCs proliferation. Overexpression of miR-448 induced ki-67 mRNA and protein expression. Moreover, we identified MEF2C was a direct target of miR-448 in VSMCs. Overexpression of miR-448 promoted VSMCs migration. Furthermore, overexpression of MEF2C decreased miR-448-induced VSMCs proliferation and migration. These evidences suggested that miR-448 played an important role in the proliferation and migration of VSMCs.

MicroRNAs in the skin: role in development, homoeostasis and regeneration

The skin is the largest organ of the integumentary system and possesses a vast number of functions. Due to the distinct layers of the skin and the variety of cells which populate each, a tightly regulated network of molecular signals control development and regeneration, whether due to programmed cell termination or injury. MicroRNAs (miRs) are a relatively recent discovery; they are a class of small non-coding RNAs which possess a multitude of biological functions due to their ability to regulate gene expression via post-transcriptional gene silencing. Of interest, is that a plethora of data demonstrates that a number of miRs are highly expressed within the skin, and are evidently key regulators of numerous vital processes to maintain non-aberrant functioning. Recently, miRs have been targeted as therapeutic interventions due to the ability of synthetic 'antagomiRs' to down-regulate abnormal miR expression, thereby potentiating wound healing and attenuating fibrotic processes which can contribute to disease such as systemic sclerosis (SSc). This review will provide an introduction to the structure and function of the skin and miR biogenesis, before summarizing the literature pertaining to the role of miRs. Finally, miR therapies will also be discussed, highlighting important future areas of research.

miR-15b mediates oxaliplatin-induced chronic neuropathic pain through BACE1 down-regulation

BACKGROUND AND PURPOSE

Although oxaliplatin is an effective anti-cancer platinum compound, it can cause painful chronic neuropathy, and its molecular mechanisms are poorly understood. MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate gene expression in a sequence-specific manner. Although miRNAs have been increasingly recognized as important modulators in a variety of pain conditions, their involvement in chemotherapy-induced neuropathic pain is unknown.

EXPERIMENTAL APPROACH

Oxaliplatin-induced chronic neuropathic pain was induced in rats by i.p. injections of oxaliplatin (2 mg·kg^-1 ) for five consecutive days. The expression levels of miR-15b and β-site amyloid precursor protein-cleaving enzyme 1 (BACE1 also known as β-secretase 1) were examined in the dorsal root ganglion (DRG). To examine the function of miR-15b, an adeno-associated viral vector encoding miR-15b was injected into the DRG in vivo.

KEY RESULTS

Among the miRNAs examined in the DRG in the late phase of oxaliplatin-induced neuropathic pain, miR-15b was most robustly increased. Our in vitro assay results determined that BACE1 was a target of miR-15b. BACE1 and miR-15b were co-expressed in putative myelinated and unmyelinated DRG neurons. Overexpression of miR-15b in DRG neurons caused mechanical allodynia in association with reduced expression of BACE1. Consistent with these results, a BACE1 inhibitor dose-dependently induced significant mechanical allodynia.

CONCLUSIONS AND IMPLICATIONS

These findings suggest that miR-15b contributes to oxaliplatin-induced chronic neuropathic pain at least in part through the down-regulation of BACE1.

Function, Role, and Clinical Application of MicroRNAs in Vascular Aging

Vascular aging, a specific type of organic aging, is related to age-dependent changes in the vasculature, including atherosclerotic plaques, arterial stiffness, fibrosis, and increased intimal thickening. Vascular aging could influence the threshold, process, and severity of various cardiovascular diseases, thus making it one of the most important risk factors in the high mortality of cardiovascular diseases. As endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) are the main cell biological basis of these pathology changes of the vasculature, the structure and function of ECs and VSMCs play a key role in vascular aging. MicroRNAs (miRNAs), small noncoding RNAs, have been shown to regulate the expression of multiple messenger RNAs (mRNAs) posttranscriptionally, contributing to many crucial aspects of cell biology. Recently, miRNAs with functions associated with aging or aging-related diseases have been studied. In this review, we will summarize the reported role of miRNAs in the process of vascular aging with special emphasis on EC and VSMC functions. In addition, the potential application of miRNAs to clinical practice for the diagnosis and treatment of cardiovascular diseases will also be discussed.

Phytosphingosine promotes megakaryocytic differentiation of myeloid leukemia cells

We report that phytosphingosine, a sphingolipid found in many organisms and implicated in cellular signaling, promotes megakaryocytic differentiation of myeloid leukemia cells. Specifically, phytosphingosine induced several hallmark changes associated with megakaryopoiesis from K562 and HEL cells including cell cycle arrest, cell size increase and polyploidization. We also confirmed that cell type specific markers of megakaryocytes, CD41a and CD42b are induced by phytosphingosine. Phospholipids with highly similar structures were unable to induce similar changes, indicating that the activity of phytosphingosine is highly specific. Although phytosphingosine is known to activate p38 mitogen-activated protein kinase (MAPK)-mediated apoptosis, the signaling mechanisms involved in megakaryopoiesis appear to be distinct. In sum, we present another model for dissecting molecular details of megakaryocytic differentiation which in large part remains obscure. [BMB Reports 2015; 48(12): 691-695]

Chungtaejeon, a Korean fermented tea, prevents the risk of atherosclerosis in rats fed a high-fat atherogenic diet

OBJECTIVE

Hypercholesterolemia is one of the well-established risk factors for cardiovascular mortality and morbidity in coronary heart disease. The aim of this study was to investigate the anti-atherogenic effect of Chungtaejeon (CTJ, a Korean fermented tea) aqueous extract on proliferation and migration of human aortic smooth muscle cells (HASMCs) in vivo and in vitro.

METHODS

The authors used high-fat atherogenic diet (HFAD) to induce hyperlipidemia in Wistar rats in in vivo animal experiments and used HASMCs for in vitro cell experiments. For the in vitro cell experiment, the proliferation of HASMCs was evaluated using the MTT assay. Similarly, the expression of matrix metalloproteinases (MMPs) in HASMCs was measured using gelatin zymography. Antimigratory activity of CTJ was revealed using the wound-healing model and Boyden 's chamber assay. In the in vivo experiment, CTJ was administered in three different doses for 20 d from the initiation of the HFAD. After 20 d, the serum lipid profile and total lipid contents in liver were measured.

RESULTS

Treatment with CTJ for 24 h dose-dependently inhibited the proliferation and migration of HASMCs and expression of MMP-2 in HASMCs. The oral administration of CTJ at concentrations of 200 and 400 mg/kg decreased the levels of low-density lipoprotein cholesterol, total serum cholesterol and hepatic cholesterol of HFAD-fed rats.

CONCLUSION

CTJ possessed strong antiproliferative, antimigratory, as well as lipid-lowering activities. Thus, CTJ can be considered as a therapeutic option in the treatment of high-fat diet-induced atherosclerosis.

miR-142-3p Is a Regulator of the TGFβ-Mediated Vascular Smooth Muscle Cell Phenotype

The transforming growth factor β (TGFβ) signaling pathway is critical for the promotion and maintenance of the contractile phenotype of vascular smooth muscle cells (VSMCs). Though multiple microRNAs (miRNAs) implicated in the regulation of the VSMC phenotype have been identified, the modulation of miRNAs in the VSMCs by TGFβ signaling has not been fully described. In this study, we identified microRNA-142-3p (miR-142-3p) as a modulator of the VSMC phenotype in response to TGFβ signaling. We show that miR-142-3p is induced upon TGFβ signaling, leading to the repression of a novel target, dedicator of cytokinesis 6 (DOCK6). The downregulation of DOCK6 by miR-142-3p is critical for cell migration. Thus, this study demonstrates that miR-142-3p is a key regulator of the TGFβ-mediated contractile phenotype of VSMCs that acts through inhibiting cell migration through targeting DOCK6.

MicroRNA-145 regulates platelet-derived growth factor-induced human aortic vascular smooth muscle cell proliferation and migration by targeting CD40

The objective of this study is to investigate the expression of microRNA (miR)-145 in human aortic vascular smooth muscle cells (VSMCs) and the effect of miR-145 in the biological behavior and expression of CD40 in VSMCs. Cells were treated with either miR-145 or miR-145 inhibitor. Cell proliferation was analyzed by a colony formation assay and a methyl thiazolyl tetrazolium assay. Cell migration and invasion were assessed using a transwell assay, an invasion assay, and a wound healing assay. A luciferase reporter assay was used to detect the interaction between miR-145 and CD40. Expression of α-SMA, calponin, osteopontin (OPN), epiregulin, activator protein-1 (AP-1) and CD40 was measured using real-time RT-PCR for mRNA levels and Western blotting for protein levels. Overexpression of miR-145 significantly inhibited VSMC proliferation, invasion and migration. Furthermore, OPN, epiregulin, AP-1 and CD40 expression at the mRNA and protein levels was down-regulated by overexpression of miR-145. However, α-SMA and calponin expression at the mRNA and protein levels was up-regulated by overexpression of miR-145. In addition, the luciferase reporter assay showed that CD40 may be a direct target gene of miR-145 in VSMC initiation and development. Moreover, these data demonstrate that the up-regulation of CD40 is critical for miR-145-mediated inhibitory effects on platelet-derived growth factor-induced cell proliferation and migration in human VSMCs. In summary, CD40, a direct target of miR-145, reverses the inhibitory effects of miR-145. These results suggest that the specific modulation of miR-145 in human VSMCs may be an attractive approach for the treatment of proliferative vascular diseases.

MicroRNA-541 promotes the proliferation of vascular smooth muscle cells by targeting IRF7

MiRNAs play crucial roles in abnormal proliferation and invasion of VSMCs. However, the roles and mechanisms of miRNAs in VSMCs are not fully understood. In our study, we demonstrated that PDGF-BB and serum induced proliferation of VSMCs led to the upregulation of miR-541. We also showed that overexpression of miR-541 promoted VSMC proliferation and invasion. In addition, Interferon regulatory factor 7 (IRF7) was found to be a potential target of miR-541 and upregulation of IRF7 could inhibit VSMC proliferation. Restored expression of miR-541 promoted IRF7-inhibited VSMCs proliferation. In conclusion, these findings suggest that inhibitors targeting miR-541 or its specific downstream molecules may be therapeutic strategy for VSMC growth-related diseases.

A Pitx2-MicroRNA Pathway Modulates Cell Proliferation in Myoblasts and Skeletal-Muscle Satellite Cells and Promotes Their Commitment to a Myogenic Cell Fate

The acquisition of a proliferating-cell status from a quiescent state as well as the shift between proliferation and differentiation are key developmental steps in skeletal-muscle stem cells (satellite cells) to provide proper muscle regeneration. However, how satellite cell proliferation is regulated is not fully understood. Here, we report that the c-isoform of the transcription factor Pitx2 increases cell proliferation in myoblasts by downregulating microRNA 15b (miR-15b), miR-23b, miR-106b, and miR-503. This Pitx2c-microRNA (miRNA) pathway also regulates cell proliferation in early-activated satellite cells, enhancing Myf5(+) satellite cells and thereby promoting their commitment to a myogenic cell fate. This study reveals unknown functions of several miRNAs in myoblast and satellite cell behavior and thus may have future applications in regenerative medicine.

MicroRNAs in skin tissue engineering

35.2 million annual cases in the U.S. require clinical intervention for major skin loss. To meet this demand, the field of skin tissue engineering has grown rapidly over the past 40 years. Traditionally, skin tissue engineering relies on the "cell-scaffold-signal" approach, whereby isolated cells are formulated into a three-dimensional substrate matrix, or scaffold, and exposed to the proper molecular, physical, and/or electrical signals to encourage growth and differentiation. However, clinically available bioengineered skin equivalents (BSEs) suffer from a number of drawbacks, including time required to generate autologous BSEs, poor allogeneic BSE survival, and physical limitations such as mass transfer issues. Additionally, different types of skin wounds require different BSE designs. MicroRNA has recently emerged as a new and exciting field of RNA interference that can overcome the barriers of BSE design. MicroRNA can regulate cellular behavior, change the bioactive milieu of the skin, and be delivered to skin tissue in a number of ways. While it is still in its infancy, the use of microRNAs in skin tissue engineering offers the opportunity to both enhance and expand a field for which there is still a vast unmet clinical need. Here we give a review of skin tissue engineering, focusing on the important cellular processes, bioactive mediators, and scaffolds. We further discuss potential microRNA targets for each individual component, and we conclude with possible future applications.

HDAC3 acts as a negative regulator of angiogenesis

Histone deacetylase-3 (HDAC3) is involved in cellular proliferation, apoptosis and transcriptional repression. However, the role of HDAC3 in angiogenesis remains unknown. HDAC3 negatively regulated the expression of angiogenic factors, such as VEGF and plasminogen activator inhibitor-1 (PAI-1). HDAC3 showed binding to promoter sequences of PAI-1. HDAC3 activity was necessary for the expression regulation of PAI-1 by HDAC3. VEGF decreased the expression of HDAC3, and the down-regulation of HDAC3 enhanced endothelial cell tube formation. HDAC3 negatively regulated tumor-induced angiogenic potential. We show the novel role of HDAC3 as a negative regulator of angiogenesis. [BMB Reports 2014; 47(4): 227-232]

Inhibition of microRNA-25 by tumor necrosis factor α is critical in the modulation of vascular smooth muscle cell proliferation

Atherosclerosis and coronary heart disease are characterized by a hyperplastic neointima and inflammation involving cytokines, such as tumor necrosis factor‑α (TNF‑α). TNF‑α is pleiotropic and mediates inflammation and proliferation in various cell types, such as vascular smooth muscle cells (VSMCs). The molecular mechanism for the pleiotropic effects of TNF‑α has not previously been fully elucidated. The current study identified that the expression of microRNA‑25 (miR‑25), a small noncoding RNA, was reduced in response to TNF‑α signaling in VSMCs. Restored miR‑25 expression inhibited cell proliferation and Ki‑67 expression. The present study indicated that cyclin‑dependent kinase 6 (CDK6) was the direct target gene of miR‑25 using mRNA and protein expression analysis, and luciferase assays. It was also observed that restored CDK6 expression in the miR‑25 mimic‑treated VSMCs partly reduced miR‑25‑mediated VSMC proliferation. In conclusion, miR‑25 is suggested to be important in TNF‑α‑induced abnormal proliferation of VSMCs.

microRNAs Distinctively Regulate Vascular Smooth Muscle and Endothelial Cells: Functional Implications in Angiogenesis, Atherosclerosis, and In-Stent Restenosis

Endothelial cells (EC) and vascular smooth muscle cells (VSMC) are the main cell types within the vasculature. We describe here how microRNAs (miRs)--noncoding RNAs that can regulate gene expression via translational repression and/or post-transcriptional degradation--distinctively modulate EC and VSMC function in physiology and disease. In particular, the specific roles of miR-126 and miR-143/145, master regulators of EC and VSMC function, respectively, are deeply explored. We also describe the mechanistic role of miRs in the regulation of the pathophysiology of key cardiovascular processes including angiogenesis, atherosclerosis, and in-stent restenosis post-angioplasty. Drawbacks of currently available therapeutic options are discussed, pointing at the challenges and potential clinical opportunities provided by miR-based treatments.

Circulating microRNAs as a fingerprint for endometrial endometrioid adenocarcinoma

BACKGROUND

Endometrial cancer is the most common malignancy of the female genital tract worldwide, and endometrial endometrioid adenocarcinoma (EEC) is the major histological type of endometrial cancer. There is a great need for better markers with high sensitivity and specificity to permit early diagnosis and proper management of EEC. The aim of our study is to identify a miRNA classifier within plasma as a noninvasive biomarker for EEC diagnosis.

METHODS

This study was a retrospective case-control analysis which contained two independent cohorts including 93 participants. First, we screened 375 miRNAs in 29 plasma samples. 9 of the miRNAs were selected to be evaluated their expression by quantitative reverse-transcriptase polymerase chain reaction. A stepwise logistic regression model was then used to establish a new classifier in the validation cohort. Area under the receiver operating characteristic curve was used to evaluate the diagnostic accuracy. Co-expression analysis was used to verify the independence of results.

RESULTS

miR-15b, -27a, and -223 were found to be differentially expressed in the EEC plasma between the two cohorts and had few connections with other miRNAs. The areas under the curve (AUC) were 0.768, 0.813, and 0.768 for miR-15b, -27a, and 223, respectively. miR-27a and CA125 can be combined as a potential non-invasive biomarker for detecting EEC, with the AUC of 0.894.

CONCLUSION

Our study demonstrated three miRNAs, including miR-15b, -27a, and -233 have a good clinical value in EEC diagnosis. The classifier, including miR-27a and CA125, demonstrated a high accuracy in the diagnosis of EEC and might serve as a novel non-invasive biomarker in the future.

MicroRNA-21 inhibits platelet-derived growth factor-induced human aortic vascular smooth muscle cell proliferation and migration through targeting activator protein-1

OBJECTIVES

This study is to investigate whether microRNA (miR)-21 inhibits platelet-derived growth factor-induced human aortic vascular smooth muscle cell (VSMC) proliferation and migration through targeting activator protein-1 (AP-1).

METHODS

VSMCs were transfected with the miR-21 or miR-21 inhibitor. Cell proliferation was determined using methyl thiazolyl tetrazolium assay. Cell migration was detected by transwell assay. Luciferase reporter assay was used to study the interaction between miR-21 and AP-1. The levels of mRNA were determined using quantitative real-time polymerase chain reaction, while protein expression was measured using Western blotting assay.

RESULTS

Low expression of miR-21 significantly inhibited VSMC proliferation, invasion and migration. The mRNA levels and protein expression of α-SMA and AP-1 were down-regulated by low expression of miR-21. In addition, luciferase reporter assay demonstrated that AP-1 might be a direct target gene of miR-21 in VSMC initiation and development. Moreover, up-regulation of AP-1 was critical for miR-21-mediated inhibitory effects on platelet-derived growth factor-induced cell proliferation and migration in human VSMCs.

CONCLUSIONS

In summary, miR-21 is a key molecule in regulating human VSMC proliferation and migration by targeting AP-1, suggesting that specific modulation of miR-21 in human VSMCs may become an attractive approach for the treatment of proliferative vascular diseases.