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MiR‐27 prevents atherosclerosis by inhibiting inflammatory responses induced by lipoprotein lipase. Overexpression of miR‐27b attenuates angiotensin‐induced atrial fibrosis. Nevertheless, studies have rarely investigated on the effect of miR‐27 in cardiomyocyte injury. H9c2 cells were transfected with miR‐27 mimic/inhibitor. Then the cell proliferation was tested by MTT assay and the cell apoptosis was detected by flow cytometry. The luciferase activity assay was utilized to analyze the relationship between miR‐27 and TGFBR1. Quantificational real‐time polymerase chain reaction and western blot were utilized to detect the cardiomyocyte differentiation marker and nuclear factor kappa B (NF‐κB) pathway. Our outcomes demonstrated that miR‐27 expression was downregulated cardiomyocyte injury subjected to hypoxia/reoxygenation (H/R). Additionally, overexpression of miR‐27 could significantly alleviate cardiomyocyte injury by regulating cell activity and apoptosis. The luciferase activity assay confirmed that transforming growth factor ß receptor 1 (TGFBR1) is a direct hallmark of miR‐27. Besides, overexpression of miR‐27 promoted the expression of TGFBR1 in H/R model. After transfection with miR‐27 mimic/inhibitor, the expression of NF‐κB pathway‐related proteins was decreased/increased. Taken together, our data manifested that miR‐27 repressed cardiomyocyte injury induced by H/R via mediating TGFBR1 and inhibiting NF‐κB signaling pathway. Furthermore, miR‐27/ TGFBR1 might be utilized as hopeful biomarkers for myocardial ischemia diagnosis and treatment.

Multiple myeloma (MM) is an incurable hematological malignancy characterized by abnormal infiltration of plasma cells in the bone marrow. MicroRNAs (miRNAs) have emerged as crucial regulators in human tumorigenesis and tumor progression. miR-27, a novel cancer-related miRNA, has been confirmed to be implicated in multiple types of human tumors; however, its biological role in MM remains largely unknown. The present study aimed to characterize the biological role of miR-27 in MM and elucidate the potential molecular mechanisms. Here we found that miR-27 was significantly up-regulated in MM samples compared with normal bone marrow samples from healthy donors. Moreover, the log-rank test and Kaplan–Meier survival analysis displayed that MM patients with high miR-27 expression experienced a significantly shorter overall survival than those with low miR-27 expression. In the current study, we transfected MM cells with miR-27 mimics or miR-27 inhibitor to manipulate its expression. Functional studies demonstrated that miR-27 overexpression promoted MM cell proliferation, facilitated cell cycle progression, and expedited cell migration and invasion; whereas miR-27 knockdown inhibited cell proliferation, induced cell cycle arrest, and slowed down cell motility. Mechanistic studies revealed that Sprouty homolog 2 (SPRY2) was a direct target of miR-27 and that rescuing SPRY2 expression reversed the promoting effects of miR-27 on MM cell proliferation, migration, and invasion. Besides, miR-27 ablation suppressed tumorigenecity of MM cells in mouse xenograft models. Collectively, our data indicate that miR-27 exerts its oncogenic functions in MM by targetting SPRY2 and that miR-27 may be used as a promising candidate target in MM treatment.

To disclose the mechanisms surrounding obesity, we selected microRNAs (miRNAs) that target genes involved in adipogenesis, angiogenesis, and inflammation and compared their expression levels in the subcutaneous adipose tissue of 40 obese and nonobese women. Mature miRNAs were extracted from subcutaneous adipose tissue samples that were collected during surgery and quantified by real-time polymerase chain reaction. miR-16 was overexpressed in the nonobese group (n-expression ratio = − 151.1; P

This study aimed to discuss the potential roles of isomiRs of miR-27 family in metabolisms associated with disease via analyses of their evolution, expression, and function. miR-27b-3p was relatively highly expressed in liver cancer samples compared to miR-27a-3p and miR-27-5p loci. The diversity of isomiRs in miR-27-3p locus is similar to that of miRNAs among homologous genes. IsomiRs exhibited variable expression across different cancer tissue types, and some of them were abnormally expressed in ob/ob mice. Further experimental validation indicated that the protein expression of metabolism-related proteins, including PEPCK, G6Pase, FAS, and CPT1A, were significantly suppressed when canonical miR-27b was transfected into AML-12 cells. In contrast, the expression of these proteins was only slightly inhibited by isomiR-27b-1 or isomiR-27b-2 after transfection into AML-12 cells. These observations support that isomiRs exhibiting sequence divergence are functional regulatory molecules, and that they may contribute to biological processes via coordinated interactions in regulatory networks.

Objective The recruitment and commitment of mesenchymal stem cells and their terminal differentiation into adipocytes are the main pathways for increasing adipocyte cell numbers during obesity. Our previous studies have shown that lysyl oxidase (Lox) is upregulated and functions as an essential factor during bone morphogenetic protein 4 (BMP4) -induced C3H10T1/2 cell adipocytic lineage commitment. However, the mechanism of Lox regulation during adipogenic lineage commitment has remained largely unestablished. Methods Samples of adipose tissue from humans with different BMI and C57BL/6 mice with a high-fat diet were used to compare microRNA-27 (miR-27) expression level associated with obesity. Taqman assays were used for miR-27 expression detection and Oil Red O staining for adipogenesis analysis. Results A negative correlation was identified between Lox expression level and miR-27 expression in both BMP4-treated C3H10T1/2 cells and human subcutaneous adipose tissues. A Lox 3′ UTR luciferase reporter assay showed that miR-27 directly targeted Lox. Furthermore, overexpression of miR-27 impaired BMP4-induced upregulation of Lox and adipocytic commitment, which could be rescued by overexpression of mature Lox. Conversely, miR-27 inhibition by specific inhibitors increased Lox expression and adipocytic commitment. Conclusions Taken together, these results suggest a novel role for miR-27 in repressing adipogenic lineage commitment by targeting Lox.

The negative role of the activated stimulator of IFN genes (STING) has been uncovered in autoinflammatory disease and cancer. However, the role of STING in virus-related carcinogenesis is not well known. Herein, HPV(+) tongue squamous cell carcinoma (TSCC) (n=25) and HPV(-) TSCC samples (n=25) were randomly collected and were verified by in situ hybridization (ISH) and p16 immunohistochemistry (IHC) to assess the expression and activated status of STING through IHC. The results showed that the expression of STING was up-regulated during the development of TSCC. Interestingly, although the expression of STING showed no difference between HPV(+/-) TSCC samples, the activated status of STING with dark staining around the nucleus was observed in HPV(+) TSCC samples. The role of activated STING was analyzed in three cell lines by siRNA and indicated that activated STING had no impact on cell viability or apoptosis but promoted the induction of several immunosuppressive cytokines, e.g., IL-10, IDO and CCL22, which facilitated the infiltration of regulatory T cells (Tregs). Moreover, increased infiltration of Foxp3(+) Tregs along with increased expression of CCL22 was confirmed in HPV(+) TSCC samples. An inhibitor of the MAPK/AP-1 pathway (U0126) and the silencing of c-jun significantly suppressed CCL22 induction and the recruitment of Tregs by activated STING. Furthermore, down-regulated miR-27 was verified in independent fresh TSCC samples (n=50) and eight cell lines, which enhanced STING activation and led to increased CCL22 expression for Tregs recruitment in the TSCC microenvironment. Therefore, our findings provided distinct insight into the side effects of activated STING in HPV-related carcinogenesis.

miR-27 plays a negative role in the regulation of adipogenesis. However, the molecular mechanism still remains to be clarified. In the present study, we found that miR-27 inhibits adipogenesis partially by repressing the early adipogenic transcription factor cAMP response element-binding protein by directly targeting its 3' untranslated region. In addition, we demonstrated that tumor necrosis factor-α (TNF-α) treatment up-regulates miR-27 through the NF-κB pathway. Furthermore, anti-miR-27 reduces the TNF-α-induced inhibition of adipogenesis. Simultaneously, the levels of miR-27 expression were decreased in mature adipocytes of obese mice when compared with lean mice. Our data revealed a novel mechanism of miR-27 in the regulation of adipogenesis.

Atherosclerosis (As) is now widely appreciated to represent a chronic inflammatory reaction of the vascular wall in response to dyslipidemia and endothelial distress involving the inflammatory recruitment of leukocytes and the activation of resident vascular cells. MicroRNAs (miRNAs) are a group of endogenous, small (~22 nucleotides in length) non-coding RNA molecules, which function specifically by base pairing with mRNA of genes, thereby induce translation repressions of the genes within metazoan cells. Recently, the function of miR-27, one of the miRNAs, in the initiation and progression of atherosclerosis has been identified. In vivo and in vitro studies suggest that miR-27 may serve as a diagnostic and prognostic marker for atherosclerosis. More recently, studies have identified important roles for miR-27 in angiogenesis, adipogenesis, inflammation, lipid metabolism, oxidative stress, insulin resistance and type 2 diabetes, etc. In this review, we focus on the role of miR-27 in the development of vulnerable atherosclerotic plaques, potential as a disease biomarker and novel therapeutic target in atherosclerosis.

Worldwide obesity is a growing health problem, associated with increased risk of chronic disease. Understanding the molecular basis of adipogenesis and fat cell development in obesity is essential to identify new biomarkers and therapeutic targets for the development of anti-obesity drugs. microRNAs (miRNAs) appear to play regulatory roles in many biological processes associated with obesity, including adipocyte differentiation, insulin action and fat metabolism. Recent studies show miRNAs are dysregulated in obese adipose tissue. During adipogenesis miRNAs can accelerate or inhibit adipocyte differentiation and hence regulate fat cell development. In addition miRNAs may regulate adipogenic lineage commitment in multipotent stem cells and hence govern fat cell numbers. Recent findings suggest miR-519d may be associated with human obesity, but larger case-control studies are needed. Few miRNA targets have been experimentally validated in adipocytes but interestingly both miR-27 and miR-519d target PPAR family members, which are well established regulators of fat cell development. In this review recent advances in our understanding of the role of miRNAs in fat cell development and obesity are discussed. The potential of miRNA based therapeutics targeting obesity is highlighted as well as recommendations for future research which could lead to a breakthrough in the treatment of obesity.

Aims Non-coding RNA has been recently demonstrated to be a novel mechanism for modulation of gene expression at the post-transcriptional level. The importance of microRNAs in the cardiovascular system is now apparent. Mutations of distinct microRNAs have provided evidence for fundamental roles of microRNAs during cardiovascular development. However, there is limited information about global microRNA profiles during mouse heart development. In this study, we have gained insight from the expression profiles of microRNAs during mouse ventricular development by microarray and qRT-PCR analysis. Methods and results Our microarray analysis reveals that relatively few microRNAs display either increasing or decreasing expression profiles during ventricular chamber formation. Interestingly, most of the differentially expressed microRNAs display a rather discrete peak of expression at particular developmental stages. Furthermore, we demonstrate that microRNA-27b (miR-27b) displays an overt myocardial expression during heart development and that the transcription factor-encoding gene Mef2c is an miR-27b target. Conclusion Our data present a comprehensive profile of microRNA expression during ventricular maturation, providing an entry point for investigation of the functional roles of the most abundantly and differentially expressed microRNAs during cardiogenesis.

MicroRNAs (miRNAs) are involved in a plethora of important biological processes, from embryonic development to homeostasis in adult tissues. Recently, miRNAs have emerged as a class of epigenetic regulators of metabolism and energy homeostasis. We have investigated the role of miRNAs in the regulation of adipogenic differentiation. In this article, we demonstrate that the miR-27 gene family is downregulated during adipogenic differentiation. Overexpression of miR-27 specifically inhibited adipocyte formation, without affecting myogenic differentiation. We also found that expression of miR-27 resulted in blockade of expression of PPARgamma and C/EBPalpha, the two master regulators of adipogenesis. Importantly, expression of miR-27 was increased in fat tissue of obese mice and was regulated by hypoxia, an important extracellular stress associated with obesity. Our data strongly suggest that miR-27 represents a new class of adipogenic inhibitors and may play a role in the pathological development of obesity.

MicroRNAs are noncoding RNAs of approximately 22–24 nucleotides which are capable of interacting with the 3′ untranslated region of coding RNAs (mRNAs), leading to mRNA degradation and/or protein translation blockage. In recent years, differential microRNA expression in distinct cardiac development and disease contexts has been widely reported, yet the role of individual microRNAs in these settings remains largely unknown. We provide herein evidence of the role of miR-27 and miR-125 regulating distinct muscle-enriched transcription factors. Overexpression of miR-27 leads to impair expression ofMstnandMyocdin HL1 atrial cardiomyocytes but not in Sol8 skeletal muscle myoblasts, while overexpression of miR-125 resulted in selective upregulation ofMef2din HL1 atrial cardiomyocytes and downregulation in Sol8 cells. Taken together our data demonstrate that a single microRNA, that is, miR-27 or miR-125, can selectively upregulate and downregulate discrete number of target mRNAs in a cell-type specific manner.

Currently, obesity has become a worldwide health problem. Adipocyte differentiation is closely associated with the onset of obesity. Our previous studies suggested that persimmon tannin might be a potent anti-adipogenic dietary bioactive compound. However, the mechanism of persimmon tannin on adipocyte differentiation is still unknown. The purpose of this study was to investigate the effect of persimmon tannin on adipogenic differentiation in 3T3-L1 preadipocytes and the underlying mechanisms. Adipogenic differentiation was induced by cocktail in the presence or absence of persimmon tannin. Intracellular lipid accumulation was determined by Oil red O staining and enzymatic colorimetric methods. Gene expression and protein levels were measured by real time RT-PCR and Western blot. Persimmon tannin inhibited intracellular lipid accumulation markedly, and the inhibitory effect was largely limited to the early stage of adipocyte differentiation. Persimmon tannin suppressed the expression of C/EBPα and peroxisome proliferator-activated receptor-γ (PPARγ), significantly. Furthermore, genes related to lipogenesis, such as sterol regulatory element-binding protein 1, were down-regulated by persimmon tannin. In addition, adipocyte fatty acid binding protein (aP2), which is a target gene of PPARγ, was suppressed by persimmon tannin notably. Correspondingly, the expression of miR-27a and miR-27b were up-regulated by persimmon tannin from Day 2 to Day 8 significantly. Persimmon tannin inhibited adipocyte differentiation through regulation of PPARγ, C/EBPα and miR-27 in early stage of adipogenesis.

MicroRNAs (miRNAs) play an essential role in regulating cell differentiation either by inhibiting mRNA translation or by inducing its degradation. However, the role of miRNAs in odontoblastic cell differentaion is largely unknown. In the present study, we demonstrate that the expression of miR-27 was significantly increased during MDPC-23 odontoblastic cell differentiation. Furthermore, the up-regulation of miR-27 promotes the differentiation of MDPC-23 odontoblastic cells and accelerates mineralization without cell proliferation. In addition, our results of target gene prediction revealed that the mRNA of adenomatous polyposis coli (APC) associated with Wnt/β-catenin signaling pathway has miR-27 binding site in the its 3' UTR and is suppressed by miR-27. Subsequentially, the down-regulated APC by miR-27 triggered the activation of Wnt/β-catenin signaling through accumulation of β-catenin in the nucleus. Our data suggest that miR-27 promotes MDPC-23 odontoblastic cell differentiation by targeting APC and activating Wnt/β-catenin signaling. Therefore, miR-27 might be considered a critical candidate as an odontoblastic differentiation molecular target for the development of miRNA based therapeutic agents in the dental medicine.

MiRNAs are small non-coding RNAs that significantly regulate the translation of protein coding genes in higher organisms. MicroRNAs are involved in almost every biological process, including early development, lineage commitment, growth and differentiation, cell death, and metabolic control. Misregulation of miRNAs belonging to the intergenic miR-23a-miR-27a-miR-24-2 cluster has been recently associated to cardiac and skeletal muscle diseases, and they are up-regulated in hypertrophic cardiomyopathy and skeletal muscle atrophy. Despite these facts, the basal transcriptional regulation of miR-23a/miR-27-a/miR-24-2 cluster and how it is altered under pathological conditions remain unclear. In this study, we identified and functionally characterized conserved upstream and downstream regulatory sequences from the miR-23a-miR-27a-miR-24-2 locus that are implicated on its transcriptional control. Our data demonstrate that Srf plays a pivotal role in modulating miR-23a-miR-27a-miR-24-2 cluster proximal promoter activity. Importantly, pro-hypertrophic signalling pathways such as those driven by angiotensin II and norepinephrine also regulate miR-23a-miR-27a-miR-24-2 cluster proximal promoter activity. Taking together, our results provide new insights into the regulatory networks driving miR-23a-miR-27a-miR-24-2 cluster expression in cardiac and skeletal muscles.

Prohibitin (PHB) has been reported to play a crucial role in adipocyte differentiation and mitochondrial function. However, the regulative mechanism of PHB during adipogenesis remains unclear. In this study, we determined that the levels of both microRNA (miR)-27a and miR-27b were down-regulated following adipogenic induction of human adipose-derived stem cells, whereas the mRNA level of PHB was up-regulated. Overexpression of miR-27a or miR-27b inhibited PHB expression and adipocyte differentiation. Using PHB 3′-UTR luciferase reporter assay, we observed that miR-27a and miR-27b directly targeted PHB in human adipose-derived stem cells. A compensation of PHB partially restored the adipogenesis inhibited by miR-27. Moreover, we demonstrated the novel finding that ectopic expression of miR-27a or miR-27b impaired mitochondrial biogenesis, structure integrity, and complex I activity accompanied by excessive reactive oxygen species production. Our data suggest that miR-27 is an anti-adipogenic microRNA partly by targeting PHB and impairing mitochondrial function. Pharmacological modulation of miR-27 function may provide a new therapeutic strategy for the treatment of obesity.

BackgroundMicroRNA-27a (miR-27a) is thought to be an onco-microRNA that promotes tumor growth and metastasis by downregulating ZBTB10. The potential predictive value of miR-27a was studied in breast cancer patients.MethodsThe expression of miR-27a and ZBTB10 was examined in 102 breast cancer cases using in situ hybridization (ISH) and immunohistochemistry techniques and were evaluated semi-quantitatively by examining the staining index. The Correlation of miR-27a and ZBTB10 expression was analyed by Spearman Rank Correlation. The association of miR-27a and ZBTB10 expression with clinicopathological characteristics was analyzed using the χ(2) test, and their effects on patient survival were analyzed by a log-rank test and the Kaplan-Meier method. Univariate and multivariate Cox regression analyses were used to evaluate the prognostic values of miR-27a and ZBTB10.ResultsmiR-27a was markedly up-regulated in invasive breast cancers that expressed low levels of ZBTB10 (PConclusionsHigh miR-27a expression is associated with poor overall survival in patients with breast cancer, which suggests that miR-27a could be a valuable marker of breast cancer progression.

MicroRNAs (miRNAs) are small non-coding RNAs that control expression of complementary target mRNAs. A growing number of miRNAs has been implicated in the pathogenesis of cardiac diseases, mostly based not on functional data, but on the observation that they are dysregulated in diseased myocardium. Consequently, our knowledge regarding a potential cardiac role of the majority of miRNAs is limited. Here, we report the development of an assay format that allows the simultaneous analysis of several hundred molecules with regard to their phenotypic effect on primary rat cardiomyocytes. Using automated microscopy and an edge detection algorithm, this assay achieved high reproducibility and a robust assessment of cardiomyocyte size as a key parameter. Screening a library of synthetic miRNAs revealed several miRNAs previously not recognized as pro- or anti-hypertrophic. Out of these, we selected nine miRNAs and confirmed the pro-hypertrophic potential of miR-22, miR-30c, miR-30d, miR-212, miR-365 and the anti-hypertrophic potential of miR-27a, miR-27b and miR-133a. Quantitative analysis of the expression level of pro-hypertrophic miRNAs in primary cardiomyocytes indicated a rather low level of correlation of the phenotypic effects of individual miRNAs and their expression level. This assay allows the automated determination of cell size in primary cardiomyocytes and permitted the identification of a set of miRNAs capable of regulating cardiomyocyte hypertrophy. Elucidating their mechanism of action should provide insight into mechanisms underlying the cardiomyocyte hypertrophic response. This article is part of a Special Issue entitled ‘Possible Editorial’.

Canonical Wnt signaling is particularly important for differentiation of human mesenchymal stem cells into osteoblast. MicroRNAs (miRNAs) also play an essential role in regulating cell differentiation. However, the role of miRNAs in osteoblast differentiation remains poorly understood. Here we found that the expression of miR-27 was increased during hFOB1.19 cells differentiation. Moreover, ectopic expression of miR-27 promoted hFOB1.19 cells differentiation, whereas its repression was sufficient to inhibit cell differentiation. Western blot analysis showed that the expression level of miR-27 was positively correlated with that of β-catenin, a key protein in Wnt signaling. Further, we verified that miR-27 directly targeted and inhibited adenomatous polyposis coli (APC) gene expression, and activated Wnt signaling through accumulation of β-catenin. This study suggests miR-27 is an important mediator of osteoblast differentiation, thus offering a new target for the development of preventive or therapeutic agents against osteogenic disorders.

International audience; In mammals, microRNAs (miRNAs) can play diverse roles in viral infection through their capacity to regulate both host and viral genes. Recent reports have demonstrated that specific miRNAs change in expression level upon infection and can impact viral production and infectivity. It is clear that miRNAs are an integral component of viral-host interactions, and it is likely that both host and virus contain mechanisms to regulate miRNA expression and/or activity. To date, little is known about the mechanisms by which miRNAs are regulated in viral infection. Here we report the rapid down-regulation of miR-27a in multiple mouse cell lines as well as primary macrophages upon infection with the murine cytomegalovirus. Down-regulation of miR-27a occurs independently from two other miRNAs, miR-23a and miR-24, located within the same genomic cluster, and analysis of pri-miRNA levels suggest that regulation occurs post-transcriptionally. miR-27b, a close homolog of miR-27a (20/21 nucleotide identity), also decreases upon infection, and we demonstrate that both miR-27a and miR-27b exert an antiviral function upon over-expression. Drug sensitivity experiments suggest that virus entry is not sufficient to induce the down-regulation of miR-27 and that the mechanism requires synthesis of RNA. Altogether, our findings indicate that miR-27a and miR-27b have antiviral activity against MCMV, and that either the virus or the host encodes molecule(s) for regulating miR-27 accumulation, most likely by inducing the rapid decay of the mature species.