The microRNA miR-34c inhibits vascular smooth muscle cell proliferation and neointimal hyperplasia by targeting stem cell factor

Inhibition of microRNA-34c reduces detrusor ROCK2 expression and urinary bladder inflammation in experimental cystitis

Interstitial cystitis (IC), also called painful bladder syndrome (PBS), is 2 to 5 times more common in women than in men, yet its cause and pathogenesis remain unclear. In our study using the cyclophosphamide (CYP)-induced mouse model of cystitis, histological evaluation of the urinary bladder (UB) lamina propria (LP) showed immune cell infiltrations, indicating moderate to severe inflammation. In this study, we noticed a differential expression of a subset of microRNAs (miRs) in the UB cells (UBs) of CYP-induced cystitis as compared to the control. UB inflammatory scores and inflammatory signaling were also elevated in CYP-induced cystitis as compared to control. We identified eight UBs miRs that exhibited altered expression after CYP induction and are predicted to have a role in inflammation and smooth muscle function (miRs-34c-5p, -34b-3p, -212-3p, -449a-5p, -21a-3p, -376b-3p, -376b-5p and - 409-5p). Further analysis using ELISA for inflammatory markers and real-time PCR (RT-PCR) for differentially enriched miRs identified miR-34c as a potential target for the suppression of UB inflammation in cystitis. Blocking miR-34c by antagomir ex vivo reduced STAT3, TGF-β1, and VEGF expression in the UBs, which was induced during cystitis as compared to control. Interestingly, miR-34c inhibition also downregulated ROCK2 but elevated ROCK1 expression in bladder and detrusor cells. Thus, the present study shows that targeting miR-34c can mitigate the STAT3, TGF-β, and VEGF, inflammatory signaling in UB, and suppress ROCK2 expression in UBs to effectively suppress the inflammatory response in cystitis. This study highlights miR-34c as a potential biomarker and/or serves as the basis for new therapies for the treatment of cystitis.

Longitudinal dynamics of circulating miRNAs in a swine model of familial hypercholesterolemia during early atherosclerosis

Atherosclerosis is a complex progressive disease involving intertwined biological mechanisms. We aimed to identify miRNA expression dynamics at the early stages of atherosclerosis using a large swine model (Wisconsin Miniature Swine, WMS). A total of 18 female pigs; 9 familial hypercholesterolemic (WMS-FH) and 9 normal control swine (WMS-N) were studied. miRNA sequencing was performed on plasma cell-free RNA at 3, 6, and 9 months of age. RT-qPCR validated DE miRNAs in a new cohort of animals (n = 30) with both sexes. Gene ontology and mRNA targets for DE miRNAs were identified. In vivo multimodality imaging and histopathology were performed to document the presence of atherosclerosis at termination. 20, 19, and 9 miRNAs were significantly DE between the groups at months 3, 6, and 9, respectively. Most DE miRNAs and their target genes are involved in human atherosclerosis development. Coronary atherosclerosis was documented in 7/9 WMS-FH pigs. Control animals had no lesions. miR-138, miR-152, miR-190a, and miR-196a showed a significant diagnostic power at month 3, whereas miR-486, miR-126-3p, miR-335, and miR-423-5p were of significant diagnostic power at month 9. In conclusion, specific DE miRNAs with significant discriminatory power may be promising biomarkers for the early detection of coronary atherosclerosis.

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.

Electroacupuncture Improves Intestinal Motility through Exosomal miR-34c-5p Targeting SCF/c-Kit Signaling Pathway in Slow Transit Constipation Model Rats

Background. The pathogenesis of slow transit constipation (STC) is associated with exosomal miR-34c-5p. Electroacupuncture (EA) improves gastrointestinal motility in gastrointestinal disorders, especially STC. Our study aimed to explore the mechanism by which EA improves intestinal motility by modulating the release of exosomes and the transmission of exosomal miR-34c-5p. Methods. Fifty rats were randomly divided into five groups. STC model rats were induced, and GW4869, the exosome release inhibitor, was used to inhibit the release of exosome. The serum exosomes were authenticated under a transmission electron microscope and nanoparticle tracking analysis. RT-qPCR detected the expression of miR-34c-5p in serum exosomes and colonic tissues. The fecal number in 24 hours, Bristol scores, and intestinal transit rates were used to assess intestinal motility. Subsequently, hematoxylin and eosin (H&E) staining was used to examine the colonic mucosal histology. Finally, the expression of stem cell factor (SCF) and receptor tyrosine kinase (c-Kit) protein was measured using immunohistochemistry staining. Results. We found that EA upregulated exosomal miR-34c-5p in serum and downregulated miR-34c-5p in colonic tissues ( $P<0.01$ ). EA improved fecal numbers in 24 hours, Bristol scores, and intestinal transit rates in STC rats ( $P<0.01$ ). EA recovered the colonic histological structure and enhanced the expression of SCF and c-Kit protein ( $P<0.01$ ). The therapeutic effect of EA was attenuated after inhibiting the release of the exosome. Conclusion. Our results indicated that EA improves intestinal motility in STC rats by transporting of exosomal miR-34c-5p targeting the SCF/c-Kit signaling pathway.

Protective Role of miR-34c in Hypoxia by Activating Autophagy through BCL2 Repression

Hypoxia leads to significant cellular stress that has diverse pathological consequences such as cardiovascular diseases and cancers. MicroRNAs (miRNAs) are one of regulators of the adaptive pathway in hypoxia. We identified a hypoxia-induced miRNA, miR-34c, that was significantly upregulated in hypoxic human umbilical cord vein endothelial cells (HUVECs) and in murine blood vessels on day 3 of hindlimb ischemia (HLI). miR-34c directly inhibited BCL2 expression, acting as a toggle switch between apoptosis and autophagy in vitro and in vivo. BCL2 repression by miR-34c activated autophagy, which was evaluated by the expression of LC3-II. Overexpression of miR-34c inhibited apoptosis in HUVEC as well as in a murine model of HLI, and increased cell viability in HUVEC. Importantly, the number of viable cells in the blood vessels following HLI was increased by miR-34c overexpression. Collectively, our findings show that miR-34c plays a protective role in hypoxia, suggesting a novel therapeutic target for hypoxic and ischemic diseases in the blood vessels.

Pathogenic role of microRNAs in atherosclerotic ischemic stroke: Implications for diagnosis and therapy

Ischemic stroke resulting from atherosclerosis (particularly in the carotid artery) is one of the major subtypes of stroke and has a high incidence of death. Disordered lipid homeostasis, lipid deposition, local macrophage infiltration, smooth muscle cell proliferation, and plaque rupture are the main pathological processes of atherosclerotic ischemic stroke. Hepatocytes, macrophages, endothelial cells and vascular smooth muscle cells are the main cell types participating in these processes. By inhibiting the expression of the target genes in these cells, microRNAs play a key role in regulating lipid disorders and atherosclerotic ischemic stroke. In this article, we listed the microRNAs implicated in the pathology of atherosclerotic ischemic stroke and aimed to explain their pro- or antiatherosclerotic roles. Our article provides an update on the potential diagnostic use of miRNAs for detecting growing plaques and impending clinical events. Finally, we provide a perspective on the therapeutic use of local microRNA delivery and discuss the challenges for this potential therapy.

MicroRNA-375-3p is implicated in carotid artery stenosis by promoting the cell proliferation and migration of vascular smooth muscle cells

Background

Atherosclerosis is the main cause of carotid artery stenosis (CAS) which mostly occurs in the elderly. In this paper, the expression level of miR-375-3p in asymptomatic CAS patients and its diagnostic value for asymptomatic CAS were investigated, and the effects of miR-375-3p on the cell proliferation and migration of vascular smooth muscle cells (VSMCs) was further explored.

Methods

98 healthy subjects and 101 asymptomatic CAS patients were participated in this study. qRT-PCR was used to measure the expression level of serum miR-375-3p, and the ROC curve was established to evaluate the predictive value of miR-375-3p for asymptomatic CAS. After transfection with miR-375-3p mimic or inhibitor in vitro, cell proliferation and migration were detected by CCK-8 assay, colony formation assay, and Transwell assay, respectively. The levels of TNF-α, IL-1β, IL-6 were detected by ELISA. Western blot was used to detect the protein expression of XIAP. Finally, luciferase reporter gene assay was applied to assess the interaction of miR-375-3p with target genes.

Results

The expression level of serum miR-375-3p in asymptomatic CAS patients was significantly higher than that in healthy controls, and the AUC value of ROC curve was 0.888. The sensitivity and specificity were 80.2 and 86.7%, respectively, indicating that miR-375-3p had high diagnostic value for asymptomatic CAS. In vitro cell experiments showed that up-regulation of miR-375-3p significantly promoted the proliferation and migration of VSMCs, and also promoted the generation of inflammatory factors and phenotypic transformation of VSMCs. Luciferase reporter gene assay confirmed that XIAP was a target gene of miR-375-3p and was negatively regulated by miR-375-3p.

Conclusions

In this study, miR-375-3p may have a clinical diagnostic value for asymptomatic CAS patients which need further validation. Increased miR-375-3p levels in CAS may be associated with increased proliferation and migration of VSMCs via downregulation of the apoptosis inducing gene XIAP.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02326-6.

Correlations between vitronectin, miR-520, and miR-34 in patients with stenosis of coronary arteries

BACKGROUND

In-stent restenosis usually occurs by platelet activation, neointima formation, VSMC migration, and proliferation in the position of the vessel stent. The monocytes have a magnificent role in neointimal hyperplasia since these cells recruit to the site of vessel injury through chemokines and other secretion proteins. This study is focused on the investigation of vitronectin, miR-193, miR-34, and miR-520 expression levels in PBMCs isolated from stenosed patients.

METHODS

A total of sixty subjects undergoing coronary artery angiography containing patients with stent no restenosis (n = 20), in-stent restenosis (n = 20), and healthy participants (n = 20) participated in the study. The vitronectin, miR-193, miR-34, and miR-520 expression levels were measured by the RT-qPCR technique. Data were analyzed by SPSS software.

RESULTS

The vitronectin, miR-34, and miR-520 expression levels changed significantly in patients with vessel in-stent restenosis (p = 0.02, p = 0.02, and p = 0.01, respectively). Furthermore, there were inverse correlations between the expression levels of vitronectin gene and miR-34 (r =  - 0.44, p = 0.04) as well as miR-520 (r =  - 0.5, p=0.01).

CONCLUSIONS

The molecular events in the vessel stenosis may be affected by targeting vitronectin with miR-520 and miR-34.

miR-34c inhibits PDGF-BB-induced HAVSMCs phenotypic transformation and proliferation via PDGFR-β/SIRT1 pathway

The purpose of this study was to explore the effect of miR-34c on PDGF-BB-induced HAVSMCs phenotypic transformation and proliferation via PDGFR-β/SIRT1 pathway, so as to find a new method for early diagnosis and treatment of cardiovascular disease. HA-VSMCs were treated with platelet-derived growth factor-BB (PDGF-BB) at 0 h, 12 h, 24 h, 48 h or 36 h to explore the optimal time for phenotypic transformation of VSMCs. And then, PDGF-BB-induced HA-VSMCs were transfected with miR-34c mimics/mimics NC and pcDNA3.1-PDGFR-β/pcDNA3.1-NC to observe cell biological behaviour. CCK8 was used to detect cell proliferation activity. Transwell chamber assay was used to detect cell invasion. Early apoptosis was analyzed by flow cytometry. The expression of α-SMA and Smemb was detected by immunofluorescence staining. The expressions of PDGFR-β, IRF9, Acetyl-NF-κB/p65, Acetyl-p53 and CyclinD1 were analyzed by Western blot analysis. The expression of miR-34a, miR-34b and miR-34c was detected by RT-PCR, and the targeting relationship between miR-34c and PDGFR-β was detected by luciferase reporting assay. The results indicated the proliferation and migration of PDGF-BB-induced HA-VSMCs significantly increased, and apoptosis significantly decreased. Besides, α-SMA decreased significantly, while Smemb increased significantly. Furthermore, expressions of PDGFR-β, IRF9, Acetyl-NF-κB/p65, Acetyl-p53 and CyclinD1 increased significantly, and SIRT1 decreased significantly. Experimental results showed that, miR-34c mimics significantly inhibited cell proliferation and migration, and promoted cell apoptosis, and miR-34c inhibitor had the opposite effects. MiR-34c mimics significantly increased α-SMA expression and decreased Smemb expression, while the opposite effects were reflected after transfection with miR-34c inhibitor. Moreover, miR-34c mimics significantly decreased the expressions of PDGFR-β, IRF9, Acetyl-NF-κB/p65, Acetyl-p53 and CyclinD1, and significantly increased the expression of SIRT1, while miR-34c inhibitor had the opposite effects. Luciferase assay confirmed that PDGFR-β was a potential target of miR-34c. Subsequently, PDGF-BB-induced HA-VSMCs were co-transfected with miR-34c mimics and pcDNA3.1-PDGFR-β. The results indicated that PDGFR-β reversed the biological function of miR-34c mimic. The results revealed the potential application value of miR-34c as a marker molecule of phenotypic transformation, providing a potential target for improving phenotypic transformation.

Minor allele of rs55763075 located in MTHFR is associated with the risk of cognitive impairment after anesthesia via modulating miR-34b

This study aimed to investigate the association between cognitive impairment after general anesthesia and rs55763075 polymorphisms. We enrolled and grouped patients undergoing general anesthesia according to their genotypes of rs55763075 polymorphism. Mini–Mental State Examination (MMSE) scoring was performed to evaluate the cognitive status of patients. Quantitative real-time PCR was carried out to analyze the expression of methylenetetrahydrofolate reductase (MTHFR) mRNA and miR-34b while Western blot was performed to evaluate the expression of MTHFR protein. Furthermore, we studied the effect of rs55763075 polymorphism on the expression of MEHFR via luciferase assay. Accordingly, we found that the MMSE score in GG/GA groups was significantly higher than that in AA group. And a significant reduction of MTHFR mRNA expression was observed in the serum and peripheral blood mononuclear cells (PBMCs) of patients carrying AA genotype compared with the patients carrying GG/GA genotypes. Moreover, the MTHFR expression was much lower in the cultured AA-genotyped cells transfected with miR-34b. Luciferase assay results also showed that miR-34b transfection reduced luciferase activity in the cells carrying A allele but not in cells carrying G allele. In summary, the data of this study showed that minor allele (A) of rs55763075 polymorphisms in the 3'-untranslated region of MTHFR mRNA generated a potential binding site for miR-34b, which led to reduced level of folic acid in the patients carrying the AA genotype. Furthermore, we found that the MMSE score of AA-genotyped patients was lower than that of patients carrying GG/GA genotypes.

MiR-377-3p inhibits atherosclerosis-associated vascular smooth muscle cell proliferation and migration via targeting neuropilin2

Vascular smooth muscle cell (VSMC) proliferation and migration are vital to atherosclerosis (AS) development and plaque rupture. MicroRNA-377-3p (miR-377-3p) has been reported to inhibit AS in apolipoprotein E knockout (ApoE^−/−) mice. Herein, the mechanism underlying the effect of miR-377-3p on alleviating AS is explored. In vivo experiments, ApoE^−/− mice were fed with high-fat diet (HFD) to induce AS and treated with miR-377-3p agomir or negative control agomir (agomir-NC) on week 0, 2, 4, 6, 8, 10 after HFD feeding. MiR-377-3p was found to restore HFD-induced AS lesions and expressions of matrix metalloproteinase (MMP)-2, MMP-9, α-smooth muscle actin (α-actin) and calponin. In in vitro experiments, human VSMCs were tranfected with miR-377-3p agomir or agomir-NC, followed by treatment with oxidized low-density lipoprotein (ox-LDL). MiR-377-3p was observed to significantly inhibit ox-LDL-induced VSMC proliferation characterized by inhibited cell viability, expressions of proliferating cell nuclear antigen (PCNA), cyclin D1 and cyclin E and cell cycle transition from G₁ to S phase accompanied with less 5-Ethynyl-2′-deoxyuridine (EdU)-positive cells. Furthermore, MiR-377-3p significantly inhibited ox-LDL-induced VSMC migration characterized by inhibited wound closure and decreased relative VSMC migration. Besides, neuropilin2 (NRP2) was verified as a target of miR-377-3p. MiR-377-3p was observed to inhibit NRP2 expressions in vivo and in vitro. Moreover, miR-377-3p significantly inhibited MMP-2 and MMP-9 expressions in human VSMCs. Additionally, miR-377-3p-induced inhibition of VSMC proliferation and migration could be attenuated by NRP2 overexpression. These results indicated that miR-377-3p inhibited VSMC proliferation and migration via targeting NRP2. The present study provides an underlying mechanism for miR-377-3p-based AS therapy.

MicroRNA-212-5p and its target PAFAH1B2 suppress vascular proliferation and contraction via the downregulation of RhoA

Vascular remodeling and contraction contribute to the development of hypertension. We investigated the role of miR-212-5p and its downstream target in vascular smooth muscle cell (VSMC) proliferation, migration, and contraction. MicroRNA microarray and PCR analyses showed that miR-212-5p expression was increased with angiotensin II treatment in vivo and in vitro. Moreover, miR-212-5p mimic treatment attenuated and miR-212-5p inhibitor treatment increased VSMC proliferation and migration. Additionally, miR-212-5p mimic treatment suppressed VSMC contraction and related gene expression [Ras homolog gene family member A (RhoA) and Rho-associated protein kinase 2], while miR-212-5p inhibitor treatment exerted opposite effects. Bioinformatics analysis revealed that platelet-activating factor acetylhydrolase 1B2 (PAFAH1B2) is a target of miR-212-5p. miR-212-5p mimic treatment significantly reduced and miR-212-5p inhibitor treatment increased PAFAH1B2 expression. Furthermore, PAFAH1B2 expression was decreased in angiotensin II-treated aortic tissues and VSMCs. PAFAH1B2 was ubiquitously expressed in most adult rat tissues. In the vasculature, PAFAH1B2 was only distributed in the cytoplasm. PAFAH1B2 overexpression decreased A10 cell proliferation, while PAFAH1B2 knockdown increased A10 cell proliferation and cyclin D1 mRNA levels. PAFAH1B2 knockdown stimulated VSMC contraction and RhoA expression. These results suggest that miR-212-5p and PAFAH1B2 are novel negative regulators of VSMC proliferation, migration, and contraction in hypertension.

miR-27a-3p Targets ATF3 to Reduce Calcium Deposition in Vascular Smooth Muscle Cells

Vascular calcification, the ectopic deposition of calcium in blood vessels, develops in association with various metabolic diseases and atherosclerosis and is an independent predictor of morbidity and mortality associated with these diseases. Herein, we report that reduction of microRNA-27a-3p (miR-27a-3p) causes an increase in activating transcription factor 3 (ATF3), a novel osteogenic transcription factor, in vascular smooth muscle cells. Both microRNA (miRNA) and mRNA microarrays were performed with rat vascular smooth muscle cells, and reciprocally regulated pairs of miRNA and mRNA were selected after bioinformatics analysis. Inorganic phosphate significantly reduced the expression of miR-27a-3p in A10 cells. The transcript level was also reduced in vitamin D₃-administered mouse aortas. miR-27a-3p mimic reduced calcium deposition, whereas miR-27a-3p inhibitor increased it. The Atf3 mRNA level was upregulated in a cellular vascular calcification model, and miR-27a-3p reduced the Atf3 mRNA and protein levels. Transfection with Atf3 could recover the miR-27a-3p-induced reduction of calcium deposition. Our results suggest that reduction of miR-27a-3p may contribute to the development of vascular calcification by de-repression of ATF3.

LncRNA BANCR induced vascular smooth muscle cell proliferation by downregulating miR-34c methylation in atherosclerosis

Aberrant vascular smooth muscle cell (VSMCs) proliferation involves in the development of atherosclerosis. It reported that Long noncoding BRAF-activated noncoding RNA (BANCR) and miR-34c played opposite roles in the regulation of the proliferation of VSMCs, indicating that there might be a potential interaction between them. This study was to investigate the relationship between BANCR and miR-34c in atherosclerosis. Blood (5 ml) was obtained from 56 patients with atherosclerosis and 56 healthy volunteers after they were fasted overnight, and plasma was extracted from the blood. Human Aortic Smooth Muscle Cells (HASMCs) were used to perform in vitro cell experiments. RT-qPCR was performed to measure the expression of BANCR and miR-34c in plasma and HASMCs. Dual luciferase reporter assay detected the interaction between BANCR and miR-34c. CCK-8 assay was used to assess the effects of BANCR and miR-34c overexpression on the proliferation of HASMCs. Western blotting was used to assess the effects of BANCR and miR-34c overexpression on the protein expression of HMGB1, TNF-ɑ and Bcl-2. In this study, we found that BANCR was upregulated, while miR-34c was downregulated in atherosclerosis. Bioinformatics analysis showed that BANCR and miR-34c could directly interact with each other. Moreover, overexpression of BANCR could decrease the expression of miR-34c in HASMCs, but overexpression of miR-34c could not affect the expression of BANCR. Furthermore, overexpression of BACNR increased miR-34c methylation, and knockdown of endogenous BANCR decreased miR-34c methylation. In addition, overexpression of BANCR reduced the effects of miR-34c on HASMCs proliferation and reversed the effects of miR-34c on HMGB1, TNF-ɑ and Bcl-2 expression. BANCR overexpression could induce HASMCs proliferation by downregulating the miR-34c methylation. Therefore given BANCR upregulation in atherosclerosis, its expression may be considered as a novel and useful biomarker for atherosclerosis prevention and prognosis. However considering the possible effects of other underlying diseases on both BANCR expression and miR-34c in atherosclerosis, further investigation is suggested for future research.

MicroRNAs are critical in regulating smooth muscle cell mineralization and apoptosis during vascular calcification

Vascular calcification refers to the pathological deposition of calcium and phosphate minerals into the vasculature. It is prevalent in atherosclerosis, ageing, type 2 diabetes mellitus and chronic kidney disease, thus, increasing morbidity and mortality from these conditions. Vascular calcification shares similar mechanisms with bone mineralization, with smooth muscle cells playing a critical role in both processes. In the last decade, a variety of microRNAs have been identified as key regulators for the differentiation, phenotypic switch, proliferation, apoptosis, cytokine production and matrix deposition in vascular smooth muscle cells during vascular calcification. Therefore, this review mainly discusses the roles of microRNAs in the pathophysiological mechanisms of vascular calcification in smooth muscle cells and describes several interventions against vascular calcification by regulating microRNAs. As the exact mechanisms of calcification remain not fully elucidated, having a better understanding of microRNA involvement in vascular calcification may give impetus to development of novel therapeutics for the control and treatment of vascular calcification.

Prostaglandin E2 (PGE2) synthesis pathway is involved in coronary artery stenosis and restenosis

The inflammatory events related to prostaglandins may play an important role in the progression of vessel stenosis. The aim of this study was to investigate the monocyte PTGES and 15-PGDH gene expression levels and the serum 13,14-dihyro-15-keto-PGF2α value involved in PGE2 metabolism in patients with coronary artery stenosis and restenosis. Moreover, the effects of miR-520, miR-1297 and miR-34 were studied on the gene expression levels. A total of sixty subjects referred for coronary angiography including healthy controls (stenosis <5%), subjects with stent no restenosis) SNR, stenosis <5%) and subjects in stent restenosis (ISR, restenosis >70%) were participated in the study. The gene expression levels and the serum 13,14-dihyro-15-keto- PGF2α value were measured by RT-qPCR and ELISA techniques, respectively. Moreover, the effects of miRNAs on the gene expression levels were investigated by the monocyte transfection of miR/PEI complexes. The PTGES and 15-PGDH gene expression levels and serum 13,14-dihyro-15-keto- PGF2α value increased significantly (P <0.05). Based on the miR-520 and miR-34 expression levels, the miR/PEI transfection studies were confirmed significantly the gene expression changes. The monocyte PGE2 synthesis pathway is actively considered in the SNR and ISR patients and might be related to miR-34 and miR-520 functions.

The microRNA miR-134-5p induces calcium deposition by inhibiting histone deacetylase 5 in vascular smooth muscle cells

Calcium deposition in vascular smooth muscle cells (VSMCs) is a form of ectopic ossification in blood vessels. It can result in rigidity of the vasculature and an increase in cardiac events. Here, we report that the microRNA miR-134-5p potentiates inorganic phosphate (Pi)-induced calcium deposition in VSMCs by inhibiting histone deacetylase 5 (HDAC5). Using miRNA microarray analysis of Pi-treated rat VSMCs, we first selected miR-134-5p for further evaluation. Quantitative RT-PCR confirmed that miR-134-5p was increased in Pi-treated A10 cells, a rat VSMC line. Transfection of miR-134-5p mimic potentiated the Pi-induced increase in calcium contents. miR-134-5p increased the amounts of bone runt-related transcription factor 2 (RUNX2) protein and bone morphogenic protein 2 (BMP2) mRNA in the presence of Pi but decreased the expression of osteoprotegerin (OPG). Bioinformatic analysis showed that the HDAC5 3'untranslated region (3'UTR) was one of the targets of miR-134-5p. The luciferase construct containing the 3'UTR of HDAC5 was down-regulated by miR-134-5p mimic in a dose-dependent manner in VSMCs. Overexpression of HDAC5 mitigated the calcium deposition induced by miR-134-5p. Our results suggest that a Pi-induced increase of miR-134-5p may cause vascular calcification through repression of HDAC5.

Aberration methylation of miR-34b was involved in regulating vascular calcification by targeting Notch1

Vascular calcification is one of the most important factors for cardiovascular and all-cause mortality in patients with end-stage renal diseases (ESRD). The current study was aimed to investigate the function and mechanisms of miR-34b on the calcification of vascular smooth muscle cells (VSMCs) both in vitro and in vivo. We found that the expression of miR-34b was significantly suppressed in VSMCs with high inorganic phosphate (Pi) treatment, as well as mouse arteries derived from 5/6 nephrectomy with a high-phosphate diet (0.9% Pi, 5/6 NTP) and human renal arteries from uraemia patients. Overexpression of miR-34b alleviated calcification of VSMCs, while VSMCs calcification was enhanced by inhibiting the expression of miR-34b. Bisulphite sequencing PCR (BSP) uncovered that CpG sites upstream of miR-34b DNA were hypermethylated in calcified VSMCs and calcified arteries due to 5/6 NTP, as well as calcified renal arterial tissues from uraemia patients. Meantime, increased DNA methyltransferase 3a (DNMT3a) resulted in the hypermethylation of miR-34b in VSMCs, while 5-aza-2′-deoxycytidine (5-aza) reduced the methylation rate of miR-34b and restored the expression of miR-34b in VSMCs. When DNMT3a was knocked down using DNMT3a siRNA, the effect of 3.5 mM of Pi on calcification of VSMCs was abrogated. In addition, Notch1 was validated as the functional target of miR-34b and involved in the process of calcification of VSMCs. Taken together, our data showed a specific role for miR-34b in regulating calcification of VSMCs both in vitro and in vivo, which was regulated by upstream DNA methylation of miR-34b and modulated by the downstream target gene expression, Notch1. These results suggested that modulation of miR-34b may offer new insight into a novel therapeutic approach for vascular calcification.

Implication of the p53-Related miR-34c, -125b, and -203 in the Osteoblastic Differentiation and the Malignant Transformation of Bone Sarcomas

The formation of the skeleton occurs throughout the lives of vertebrates and is achieved through the balanced activities of two kinds of specialized bone cells: the bone-forming osteoblasts and the bone-resorbing osteoclasts. Impairment in the remodeling processes dramatically hampers the proper healing of fractures and can also result in malignant bone diseases such as osteosarcoma. MicroRNAs (miRNAs) are a class of small non-coding single-strand RNAs implicated in the control of various cellular activities such as proliferation, differentiation, and apoptosis. Their post-transcriptional regulatory role confers on them inhibitory functions toward specific target mRNAs. As miRNAs are involved in the differentiation program of precursor cells, it is now well established that this class of molecules also influences bone formation by affecting osteoblastic differentiation and the fate of osteoblasts. In response to various cell signals, the tumor-suppressor protein p53 activates a huge range of genes, whose miRNAs promote genomic-integrity maintenance, cell-cycle arrest, cell senescence, and apoptosis. Here, we review the role of three p53-related miRNAs, miR-34c, -125b, and -203, in the bone-remodeling context and, in particular, in osteoblastic differentiation. The second aim of this study is to deal with the potential implication of these miRNAs in osteosarcoma development and progression.

Ursodeoxycholic acid inhibits intimal hyperplasia, vascular smooth muscle cell excessive proliferation, migration via blocking miR-21/PTEN/AKT/mTOR signaling pathway

Excessive migration and proliferation of vascular smooth muscle cells (VSMCs) are critical cellular events that lead to intimal hyperplasia in atherosclerosis and restenosis. In this study, we investigated the protective effects of ursodeoxycholic acid (UDCA) on intimal hyperplasia and VSMC proliferation and migration, and the underlying mechanisms by which these events occur. A rat unilateral carotid artery was ligated to induce vascular injury and the microRNA (miRNA) expression profiles were determined using miRNA microarray analysis. We observed that UDCA significantly reduced the degree of intimal hyperplasia and induced miR-21 dysregulation. Restoration of miR-21 by agomir-miR-21 reversed the protective effects of UDCA on intimal hyperplasia and proliferation in vivo. In vitro, UDCA suppressed PDGF-BB-induced VSMC proliferation, invasion and migration in a dose-dependent manner, whereas the suppressive effect of UDCA was abrogated by overexpression of miR-21 in PDGF-BB-incubated VSMCs. Furthermore, we identified that miR-21 in VSMCs targeted the phosphatase and tensin homolog (PTEN), a tumor suppressor gene, negatively modulated the AKT/mTOR pathway. More importantly, we observed that that UDCA suppressed AKT/mTOR signaling pathway in the carotid artery injury model, whereas this pathway was reactivated by overexpression of miR-21. Taken together, our findings indicated that UDCA inhibited intimal hyperplasia and VSMCs excessive migration and proliferation via blocking miR-21/PTEN/AKT/mTOR signaling pathway, which suggests that UDCA may be a promising candidate for the therapy of atherosclerosis.

MiR-34b-5p Mediates the Proliferation and Differentiation of Myoblasts by Targeting IGFBP2

As key post-transcriptional regulators, microRNAs (miRNAs) play an indispensable role in skeletal muscle development. Our previous study suggested that miR-34b-5p and IGFBP2 could have a potential role in skeletal muscle growth. Our goal in this study is to explore the function and regulatory mechanism of miR-34b-5p and IGFBP2 in myogenesis. In this study, the dual-luciferase reporter assay and Western blot analysis showed that IGFBP2 is a direct target of miR-34b-5p. Flow cytometric analysis and EdU assay showed that miR-34b-5p could repress the cell cycle progression of myoblasts, and miR-34b-5p could promote the formation of myotubes by promoting the expression of MyHC. On the contrary, the overexpression of IGFBP2 significantly facilitated the proliferation of myoblasts and hampered the formation of myotubes. Together, our results indicate that miR-34b-5p could mediate the proliferation and differentiation of myoblasts by targeting IGFBP2.

The microRNAs Regulating Vascular Smooth Muscle Cell Proliferation: A Minireview

Vascular smooth muscle cell (VSMC) proliferation plays a critical role in atherosclerosis. At the beginning of the pathologic process of atherosclerosis, irregular VSMC proliferation promotes plaque formation, but in advanced plaques VSMCs are beneficial, promoting the stability and preventing rupture of the fibrous cap. Recent studies have demonstrated that microRNAs (miRNAs) expressed in the vascular system are involved in the control of VSMC proliferation. This review summarizes recent findings on the miRNAs in the regulation of VSMC proliferation, including miRNAs that exhibit the inhibition or promotion of VSMC proliferation, and their targets mediating the regulation of VSMC proliferation. Up to now, most of the studies were performed only in cultured VSMC. While the modulation of miRNAs is emerging as a promising strategy for the regulation of VSMC proliferation, most of the effects of miRNAs and their targets in vivo require further investigation.

Elucidating the contributory role of microRNA to cardiovascular diseases (a review)

Cardiovascular diseases encompassing atherosclerosis, aortic aneurysms, restenosis, and pulmonary arterial hypertension, remain the leading cause of morbidity and mortality worldwide. In response to a range of stimuli, the dynamic interplay between biochemical and biomechanical mechanisms affect the behaviour and function of multiple cell types, driving the development and progression of cardiovascular diseases. Accumulating evidence has highlighted microRNAs (miRs) as significant regulators and micro-managers of key cellular and molecular pathophysiological processes involved in predominant cardiovascular diseases, including cell mitosis, motility and viability, lipid metabolism, generation of inflammatory mediators, and dysregulated proteolysis. Human pathological and clinical studies have aimed to identify select microRNA which may serve as biomarkers of disease and their progression, which are discussed within this review. In addition, I provide comprehensive coverage of in vivo investigations elucidating the modulation of distinct microRNA on the pathophysiology of atherosclerosis, abdominal aortic aneurysms, restenosis, and pulmonary arterial hypertension. Collectively, clinical and animal studies have begun to unravel the complex and often diverse effects microRNAs and their targets impart during the development of cardiovascular diseases and revealed promising therapeutic strategies through which modulation of microRNA function may be applied clinically.

Niclosamide inhibits vascular smooth muscle cell proliferation and migration and attenuates neointimal hyperplasia in injured rat carotid arteries

BACKGROUND AND PURPOSE

The anti-helminthic drug niclosamide regulates multiple cellular signals including STAT3, AMP-activated protein kinase (AMPK), Akt, Wnt/β-catenin and mitochondrial uncoupling which are involved in neointimal hyperplasia. Here we have examined the effects of niclosamide on vascular smooth muscle cell proliferation, migration and neointimal hyperplasia and assessed the potential mechanisms.

EXPERIMENTAL APPROACH

Cell migration was measured by using wound-induced migration assay and Boyden chamber assay. Protein levels were measured by using Western blot technique. Neointimal hyperplasia in vivo was induced in rats by balloon injury to the carotid artery.

KEY RESULTS

Niclosamide treatment inhibited serum-induced (15% FBS) and PDGF-BB-induced proliferation and migration of vascular smooth muscle cells (A10 cells). Niclosamide showed no cytotoxicity at anti-proliferative concentrations, but induced cell apoptosis at higher concentrations. Niclosamide treatment inhibited serum-induced (15% FBS) and PDGF-BB-induced STAT3 activation (increased protein levels of p-STAT3 at Tyr⁷⁰⁵ ) but activated AMPK, in A10 cells. Niclosamide exerted no significant effects on β-catenin expression and the activities of ERK1/2 and Akt in A10 cells. Injection (i.p.) of soluble pegylated niclosamide (PEG5000-niclosamide) (equivalent to niclosamide 25 mg·kg^-1 ) attenuated neointimal hyperplasia following balloon-injury in rat carotid arteries in vivo.

CONCLUSIONS AND IMPLICATIONS

Niclosamide inhibited vascular smooth muscle cell proliferation and migration and attenuated neointimal hyperplasia in balloon-injured rat carotid arteries through a mechanism involving inhibition of STAT3.

MicroRNA-206 regulates vascular smooth muscle cell phenotypic switch and vascular neointimal formation

MiR-206 has been found to play a critical role in skeletal muscle proliferation, differentiation, and regeneration. However, little is known about the function of miR-206 in vascular smooth muscle cells (VSMCs) biology. In this study, we will investigate its roles in phenotypic switching of VSMCs and neointimal lesion formation. First, we identified the expression of miR-206 in VSMCs treated with various concentrations of TGFβ1 and in rat carotid arteries after angioplasty by using qPCR. TGFβ1 inhibited the expression of miR-206 and TGFβ1 inhibitor induced miR-206 expression. In VSMCs of injured vascular walls, miR-206 expression was upregulated. Then, we overexpressed miR-206 using lentivirus Lv-rno-mir-206 and knocked down miR-206 using LV-rno-mir-206-inhibitor in rat carotid arteries after angioplasty. Overexpression of miR-206 resulted in decreasing SM22α expression in VSMCs in vitro and knockdown of miR-206 suppressed neointimal lesion formation in vivo. Finally, ZFP580 (zinc finger protein 580) was identified as the direct target of miR-206 in VSMCs by using luciferase report assay. The results indicate that miR-206 is involved in phenotypic switching of VSMCs and neointimal lesion formation after angioplasty through targeting ZFP580. These findings may provide a novel therapeutic target in post-angioplasty restenosis.

Trichosanthin attenuates vascular injury-induced neointimal hyperplasia following balloon catheter injury in rats

Trichosanthin (TCS), isolated from the root tuber of Trichosantheskirilowii, a well-known traditional Chinese medicinal plant, belonging to the Cucurbitaceae family, was found to exhibit numerous biological and pharmacological activities including anti-inflammatory. However, the effects of TCS on arterial injury induced neointimal hyperplasia and inflammatory cell infiltration remains poorly understood. The aim of study was to examine the effectiveness of TCS on arterial injury-mediated inflammatory processes and underlying mechanisms. A balloon-injured carotid artery induced injury in vivo in rats was established as a model of vascular injury. After 1 day TCS at 20, 40, or 80 mg/kg/day was administered intraperitoneally, daily for 14 days. Subsequently, the carotid artery was excised and taken for immunohistochemical staining. Data showed that TCS significantly dose-dependently reduced balloon injury-induced neointima formation in the carotid artery model rat, accompanied by markedly decreased positive expression percentage proliferating cell nuclear antigen (PCNA). In the in vitro study vascular smooth muscle cells (VSMC) were cultured, proliferation stimulated with platelet-derived growth factor-BB (PDGF-BB) (20 ng/ml) and TCS at 1, 2, or 4 μM added. Data demonstrated that TCS inhibited proliferation and cell cycle progression of VSMC induced by PDGF-BB. Further, TCS significantly lowered mRNA expression of cyclinD1, cyclinE1, and c-fos, and protein expression levels of Akt1, Akt2, and mitogen-activated protein kinase MAPK (ERK1) signaling pathway mediated by PDGF-BB. These findings indicate that TCS inhibits vascular neointimal hyperplasia induced by vascular injury in rats by suppression of VSMC proliferation and migration, which may involve inhibition of Akt/MAPK/ERK signal pathway.

MiR-34c represses muscle development by forming a regulatory loop with Notch1

Since pork accounts for about 40% of global meat consumption, the pig is an important economic animal for meat production. Pig is also a useful medical model for humans due to its similarity in size and physiology. Understanding the mechanism of muscle development has great implication for animal breeding and human health. Previous studies showed porcine muscle satellite cells (PSCs) are important for postnatal skeletal muscle growth, and Notch1 signaling pathway and miRNAs regulate the skeletal muscle development. Notch1 signal pathway regulates the transcription of certain types of miRNAs which further affects target gene expression. However, the specific relationship between Notch1 and miRNAs during muscle development has not been established. We found miR-34c is decreased in PSCs overexpressed N1ICD. Through the overexpression and inhibition of mi-34c, we demonstrated that miR-34c inhibits PSCs proliferation and promotes PSCs differentiation. Using dual-luciferase reporter assay and Chromatin immunoprecipitation, we demonstrate there is a reciprocal regulatory loop between Notch1 and miR-34c. Furthermore, injection of miR-34c lentivirus into mice caused repression of gastrocnemius muscle development. In summary, our data revealed that miR-34c can form a regulatory loop with Notch1 to repress muscle development, and this result expands our understanding of muscle development mechanism.

RNAi therapy to the wall of arteries and veins: anatomical, physiologic, and pharmacological considerations

Background

Cardiovascular disease remains a major health care challenge. The knowledge about the underlying mechanisms of the respective vascular disease etiologies has greatly expanded over the last decades. This includes the contribution of microRNAs, endogenous non-coding RNA molecules, known to vastly influence gene expression. In addition, short interference RNA has been established as a mechanism to temporarily affect gene expression. This review discusses challenges relating to the design of a RNA interference therapy strategy for the modulation of vascular disease. Despite advances in medical and surgical therapies, atherosclerosis (ATH), aortic aneurysms (AA) are still associated with high morbidity and mortality. In addition, intimal hyperplasia (IH) remains a leading cause of late vein and prosthetic bypass graft failure. Pathomechanisms of all three entities include activation of endothelial cells (EC) and dedifferentiation of vascular smooth muscle cells (VSMC). RNA interference represents a promising technology that may be utilized to silence genes contributing to ATH, AA or IH. Successful RNAi delivery to the vessel wall faces multiple obstacles. These include the challenge of cell specific, targeted delivery of RNAi, anatomical barriers such as basal membrane, elastic laminae in arterial walls, multiple layers of VSMC, as well as adventitial tissues. Another major decision point is the route of delivery and potential methods of transfection. A plethora of transfection reagents and adjuncts have been described with varying efficacies and side effects. Timing and duration of RNAi therapy as well as target gene choice are further relevant aspects that need to be addressed in a temporo-spatial fashion.

Conclusions

While multiple preclinical studies reported encouraging results of RNAi delivery to the vascular wall, it remains to be seen if a single target can be sufficient to the achieve clinically desirable changes in the injured vascular wall in humans. It might be necessary to achieve simultaneous and/or sequential silencing of multiple, synergistically acting target genes. Some advances in cell specific RNAi delivery have been made, but a reliable vascular cell specific transfection strategy is still missing. Also, off-target effects of RNAi and unwanted effects of transfection agents on gene expression are challenges to be addressed. Close collaborative efforts between clinicians, geneticists, biologists, and chemical and medical engineers will be needed to provide tailored therapeutics for the various types of vascular diseases.

Persistent distention of colon damages interstitial cells of Cajal through Ca2+ -ERK-AP-1-miR-34c-SCF deregulation

Gastrointestinal motility disorders (GMDs) are attributed to loss of interstitial cells of Cajal (ICC), whose survival and function are deeply dependent on the activation of KIT/SCF signalling. Based on the facts that gastrointestinal distention is common in GMD patients and SCF produced by smooth muscle cells (SMCs) is usually decreased before ICC loss, we considered a possible contribution of persistent gastrointestinal distention/stretch to SCF deficiency. In this study, chronic colonic distention mouse model, diabetic gastrointestinal paresis mouse model, cultured mouse colonic SMCs and colon specimens from Hirschsprung's disease patients were used. The results showed that SCF was clearly decreased in distent colon of mice and patients, and microRNA array and real-time PCR indicated a concomitant increase of miR-34c in distent colon. A negative regulation of miR-34c on SCF expression was confirmed by luciferase reporter assays together with knock-down and overexpression of miR-34c in cultured colonic SMCs. Using EMSA and ChIP assays, we further consolidated that in response to persistent stretch, the transcription factor AP-1/c-Jun was highly activated in colonic SMCs and significantly promoted miR-34c transcription by binding to miR-34c promoter. Knock-down or overexpression of AP-1/c-Jun in cultured colonic SMCs leads to down- or up-regulation of miR-34c, respectively. In addition, the activation of AP-1/c-Jun was through ERK1/2 signalling provoked by Ca²⁺ overload in colonic SMCs that were subject to persistent stretch. In conclusion, our data demonstrated that persistent distention/stretch on colonic SMCs could suppress SCF production probably through Ca²⁺ -ERK-AP-1-miR-34c deregulation, resulting in ICC loss or impairment and GMD progress.

The microRNA miR-124 inhibits vascular smooth muscle cell proliferation by targeting S100 calcium-binding protein A4 (S100A4)

S100 calcium-binding protein A4 (S100A4) induces proliferation and migration of vascular smooth muscle cells (VSMCs). We aimed to find the microRNA regulating S100A4 expression. S100A4 transcripts are abruptly increased in the acute phase of carotid arterial injury 1 day later (at day 1) but gradually decreases at days 7 and 14. Bioinformatics analysis reveals that miR-124 targets S100A4. VSMC survival is attenuated by miR-124 mimic but increased by miR-124 inhibitor. miR-124 decreases immediately after carotid arterial injury but dramatically increases at days 7 and 14. miR-124 inhibitor-induced cell proliferation is blocked by S100A4 siRNA, whereas miR-124-induced cell death is recovered by S100A4. Our findings suggest that miR-124 is a novel regulator of VSMC proliferation and may play a role in the development of neointimal proliferation.

MiR-34c and PlncRNA1 mediated the function of intestinal epithelial barrier by regulating tight junction proteins in inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is originated from uncontrolled inflammation, and desired methods for IBD therapy remains the main difficult. The network comprised with miRNA and lncRNA has been verified to play an important role on diverse human diseases. In this study, we demonstrated the role of miR-34c and lncRNA PlncRNA1 on the function of intestinal barrier.

METHODS

Intestinal epithelial barrier model was constructed based on normal intestinal epithelial cell line Caco-2. 2% DSS was supplemented in the Apical side of the model cells to induce the injury of intestinal epithelial barrier. Real-time PCR or western blot was used to determine mRNA or protein expression of miR-34c, PlncRNA1, Myc-associated zinc finger protein (MAZ), zonula occludens 1 (ZO-1) and occludin.

RESULTS

DSS induced injury of intestinal epithelial barrier, while overexpression of PlncRNA1 seemed to protect intestinal epithelial barrier from injury. Tight junction (TJ) proteins ZO-1 and occludin were regulated by MAZ, while, miR-34c targeted MAZ to regulate its expression, in addition, PlncRNA1 and miR-34c bound together to regulate the expressions of MAZ, ZO-1 and occludin. The protect effects of PlncRNA1 overexpression on intestinal epithelial barrier function was reversed by overexpression of miR-34c.

CONCLUSION

MAZ and TJ proteins were involved in the function of intestinal epithelial barrier, while miR-34c and PlncRNA1 regulated the intestinal dysfunction cooperatively.

miRNA-34c inhibits myoblasts proliferation by targeting YY1

miRNAs are increasingly being implicated as key regulators of cell proliferation, apoptosis, and differentiation. miRNA-34c appears to play a crucial role in cancer pathogenesis wherein it exerts its effect as a tumor suppressor. However, the role of miR-34c in myoblast proliferation remains poorly understood. Here, we found that overexpression miR-34c inhibited myoblasts proliferation by reducing the protein and mRNA expression of cell cycle genes. In contrast, blocking the function of miR-34c promoted myoblasts proliferation and increased the protein and mRNA expression of cell cycle genes. Moreover, miR-34c directly targeted YY1 and inhibited its expression. Similar to overexpression miR-34c, knockdown of YY1 by siRNA suppressed myoblasts proliferation. Our study provides novel evidence for a role of miR-34c in inhibiting myoblasts proliferation by repressing YY1. Thus, miR-34c has the potential to be used to enhance skeletal muscle development and regeneration.

Microvesicles Derived from Inflammation-Challenged Endothelial Cells Modulate Vascular Smooth Muscle Cell Functions

Purpose: Microvesicles (MV) can modulate the function of recipient cells by transferring their contents. Our previous study highlighted that MV released from tumor necrosis factor-α (TNF-α) plus serum deprivation (SD)-stimulated endothelial progenitor cells, induce detrimental effects on endothelial cells. In this study, we investigated the potential effects of endothelial MV (EMV) on proliferation, migration, and apoptosis of human brain vascular smooth cells (HBVSMC).

Methods: EMV were prepared from human brain microvascular endothelial cells (HBMEC) cultured in a TNF-α plus SD medium. RNase-EMV were made by treating EMV with RNase A for RNA depletion. The proliferation, apoptosis and migration abilities of HBVSMC were determined after co-culture with EMV or RNase-EMV. The Mek1/2 inhibitor, PD0325901, was used for pathway analysis. Western blot was used for analyzing the proteins of Mek1/2, Erk1/2, phosphorylation Erk1/2, activated caspase-3 and Bcl-2. The level of miR-146a-5p was measured by qRT-PCR.

Results: (1) EMV significantly promoted the proliferation and migration of HBVSMC. The effects were accompanied by an increase in Mek1/2 and p-Erk1/2, which could be abolished by PD0325901; (2) EMV decreased the apoptotic rate of HBVSMC by approximately 35%, which was accompanied by cleaved caspase-3 down-regulation and Bcl-2 up-regulation; (3) EMV increased miR-146a-5p level in HBVSMC by about 2-folds; (4) RNase-treated EMV were less effective than EMV on HBVSMC activities and miR-146a-5p expression.

Conclusion: EMV generated under inflammation challenge can modulate HBVSMC function and fate via their carried RNA. This is associated with activation of theMek1/2/Erk1/2 pathway and caspase-3/Bcl-2 regulation, during which miR-146a-5p may play an important role. The data suggest that EMV derived from inflammation-challenged endothelial cells are detrimental to HBVSMC homeostatic functions, highlighting potential novel therapeutic targets for vascular diseases.

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.