MiRNA-200b level in peripheral blood predicts renal interstitial injury in patients with diabetic nephropathy.

Background: To uncover the diagnostic potential of peripheral blood microRNA-200b (miRNA-200b) in renal interstitial injury in diabetic nephropathy (DN) patients. Methods: A total of 50 diabetes subjects, 50 mild DN subjects, 50 moderate-severe DN subjects and 50 healthy subjects were included. Peripheral blood level of miRNA-200b in every subject was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Serum levels of renal function indicators were determined by enzyme-linked immunosorbent assay (ELISA). Meanwhile, relative levels of fibrosis damage indicators were examined by chemiluminescent immunoassay. Diagnostic potentials of miRNA200b in diabetes, mild DN and moderate-severe DN were assessed by depicting receiver operating characteristic (ROC) curves. Results: Peripheral blood level of miRNA-200b was higher in DN subjects than diabetes subjects without vascular complications, especially moderate-severe DN patients. Peripheral blood level of miRNA-200b in DN subjects was negatively correlated to relative levels of serum creatinine, urinary nitrogen, cystatin, TGF-b, CIV and PCIII. ROC curves demonstrated diagnostic potentials of miRNA-200b in mild and moderate-severe DN. Conclusions: Peripheral blood level of miRNA-200b is closely linked to the degree of renal interstitial injury in DN patients. MiRNA-200b may be a vital indicator in predicting the development of DN.

Effect of miRNA-200b on the proliferation and apoptosis of cervical cancer cells by targeting RhoA.

OBJECTIVE: This article aims to investigate the effect of miRNA-200b on the proliferation and apoptosis of cervical cancer cells by targeting RhoA. METHODS: HeLa cells of cervical cancer were divided into five groups: blank control group, negative control group (miRNA-200b mimic NC), miRNA-200b mimic group, RhoA-negative control group, and RhoA overexpression group. Cells were collected 48 h after transfection. The expression levels of miRNA-200b were detected by RT-PCR. Target relationship between miRNA-200b and RhoA was verified by the dual-luciferase reporter assay. RhoA mRNA and protein expression were detected by western blot and RT-PCR methods. Flow cytometry was used to detect the apoptosis of cells in each group, and the CCK8 method was used to detect the proliferation of cells in each group. The mRNA and protein expression of Bax and cyclin D1 were detected by RT-PCR and western blot. RESULTS: The results of the dual luciferase reporter assay showed that RhoA was the target gene of microRNA 200b. Compared with the blank control group and the miRNA-200b mimic-NC group, the proportion of apoptotic cells increased significantly in the miRNA-200b mimic group, and the proliferation of cells was inhibited (P < 0.05). After overexpression of RhoA, the percentage of apoptotic cells decreased and the ability of cell proliferation increased significantly (P < 0.05). CONCLUSION: miRNA-200b can inhibit the proliferation and promote the apoptosis of cervical cancer cells by targeting the RhoA gene.

miRNA-200b improves hepatic fibrosis induced by CCL4 by regulating toll-like receptor 4 in mice.

To study the effect of miRNA-200b on hepatic fibrosis induced by CCl4 in mice. The C59BL/6 mice were randomly divided into three groups (normal control [NC], CCLR model [Model], and CCl 4 + miRNA-200b [miRNA]). The hepatic fibrosis was induced by CCl 4 injected subcutaneously twice per week in Model and miRNA groups. After 6 weeks building model, the mice of miRNA group were injected the miRNA-200b from caudal vein twice per week. The mice of Model and miRNA groups were continuously fed for 3 weeks. The IL-1ß, IL-6, and TNF-α concentrations of serum were measured by enzyme-linked immunosorbent assay. The hepatic tissues of difference groups were observed by hematoxylin and eosin (H&E) staining, sirius red staining, Masson staining, and terminal deoxynucleotidyl transferase dUTP nick end labeling assay and measured toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) proteins expressions by western blot assay. The correlation between miRNA-200b and TLR4 were analyzed by dual luciferase target assay. Compared with NC group, the interleukin-1ß (IL-1ß), IL-6, and tumor necrosis factor-α (TNF-α) concentrations of Model group were significantly upregulated (P < 0.05, respectively). With miRNA-200b overexpression, the IL-1ß, IL-6, and TNF-α concentrations were significantly suppressed (P < 0.05, respectively). The pathologies were improved by H&E staining, sirius red staining, and Masson staining; meanwhile, the hepatic cell apoptosis rate was significantly suppressed (P < 0.05). The TLR4 and NF-κB protein expressions of miRNA group were significantly suppressed compared with the Model group (P < 0.05, respectively). By dual luciferase target assay, the TLR4 was a target gene of miRNA-200b. The miRNA-200b upregulation improved hepatic fibrosis induced by CCl 4 via regulation of TLR4 in vivo.

Exosome-mediated miR-200b promotes colorectal cancer proliferation upon TGF-ß1 exposure.

Exosome are emerging mediators of intercellular communication. Cancer-secreted exosome has an effect on the exosome donor cells and support cancer growth and metastasis. Here, we examine the TGF-ß1, a multifunctional cytokine involved in the regulation of cellular signaling pathways in human cancers, significantly contributes to upregulate miR-200b in exosome from colorectal cancer cell lines. The miR-200b enriched in exosome can be transferred into a new target cell to facilitating the colorectal cancer cells proliferation. Further studies showing that the exosomal miR-200b could directly target 3'-UTRs of p27 and RND3 resulted in knockdown of respective target proteins in recipient cells. Remarkably, the overexpression of p27/kip1 in HCT-116 cell, not RND3, resulted in effectively inhibited cell proliferation which induced by exosomal miR-200b. Moreover, animal experiment studies also confirmed a stimulating effect of exosomal miR-200b on colorectal cancer cell-derived xenografts. The expression p27/kip1 have decreased in tumors xenografts after injected with exosomal miR-200b. Our observations offer an evidence that whereby exosomal specific miRNA could amplify the proliferative element into the neighboring or distant cells to effective tumor growth.

Over-expressed miRNA-200b ameliorates ulcerative colitis-related colorectal cancer in mice through orchestrating epithelial-mesenchymal transition and inflammatory responses by channel of AKT2.

Our study was to explore the potential role of miRNA-200b in modulating tumorigenesis in the model of ulcerative colitis-related colorectal cancer (UCRCC) and, further, to decipher the underlying mechanisms associated with this effect. In this study, we examined a greater number of polyps or adenomas, a higher grade of epithelial dysplasia accompanied with a decrease in survival ratio in azoxymethane (AOM)/dextran sulfate sodium (DSS) model mice compared to mice treated with over-expressed miRNA-200b. Surprisingly, enforced miRNA-200b expression significantly suppressed AOM/DSS-induced up-regulation of oncologic markers including ß-catenin and CD133. Independent of this, treatment with miRNA-200b obviously attenuated inflammatory responses, as indicated by down-regulating tumor necrosis factor-α (TNF-α), transforming growth factor-ß (TGF-ß) and blockade of AKT2-mediated NF-κB/IL-6/STAT3 signaling pathway. Furthermore, a simultaneous shift in epithelial-mesenchymal transition (EMT) markers such as E-cadherin and N-cadherin were observed to be increased and decreased, respectively. Coupled with the associated influence of over-expressed miRNA-200b were change in colorectal cell morphology shown by Transmission electron microscope (TEM) and a decrease in expression of rho-kinase2 (ROCK2) together with AKT2 phosphorylation (p-AKT2). Moreover, mice which were transfected with negative control of miRNA-200b possessed results that were in line with that obtained from AOM/DSS model mice. Additionally, we demonstrated that the 3'untranslated region (UTR) of AKT2 was a direct target of miRNA-200b through bioinformatics analysis and dual-luciferase assay. Collectively, these findings suggest that miRNA-200b's contribution to tumor-suppressing program was correlated with EMT and inflammatory responses in a AKT2-dependent manner.

HIF-1α/Ascl2/miR-200b regulatory feedback circuit modulated the epithelial-mesenchymal transition (EMT) in colorectal cancer cells.

We have reported that Achaete scute-like 2 (Ascl2) transcriptionally repressed miR-200 family members and affected the epithelial-mesenchymal transition (EMT)-mesenchymal-epithelial transition (MET) plasticity in colorectal cancer (CRC) cells. However, little is known about the regulation of the Ascl2/miR-200 axis. Here, we found that hypoxia inducible factor-1α (HIF-1α) mRNA levels were positively correlated with Ascl2 mRNA levels and inversely correlated with miR-200b in CRC samples. Mechanistically, we showed that Ascl2 was a downstream target of HIF-1α and had a critical role in the EMT phenotype induced by hypoxia or HIF-1α over-expression. Hypoxia or HIF-1α over-expression activated Ascl2 expression in CRC cells in a direct transcriptional mechanism via binding with the hypoxia-response element (HRE) at the proximal Ascl2 promoter. HIF-1α-induced Ascl2 expression repressed miR-200b expression to induce EMT occurrence. Furthermore, we found HIF-1α was a direct target of miR-200b. MiR-200b bound with the 3'-UTR of HIF-1α in CRC cells. HIF-1α/Ascl2/miR-200b regulatory feedback circuit modulated the EMT-MET plasticity of CRC cells. Our results confirmed a novel HIF-1α/Ascl2/miR-200b regulatory feedback circuit in modulating EMT-MET plasticity of CRC cells, which could serve as a possible therapeutic target.

Elevated circulating micro-ribonucleic acid (miRNA)-200b and miRNA-429 levels in anovulatory women.

OBJECTIVE: To study the role of micro-RNA (miRNA)-200b and miRNA-429 in human ovulation and to measure their expression levels in ovulatory and anovulatory patients. DESIGN: Micro-RNA-200b and miRNA-429 expression analysis in human serum and granulosa cells at different phases of the ovulation cycle in normal cycling women and women undergoing assisted reproductive technology cycles. SETTING: University-affiliated hospital and academic research laboratory. PATIENT(S): Forty women (7 normally ovulating, 15 normally ovulating with pure male infertility factor, and 18 with polycystic ovary syndrome) were included in this study. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The expression profile of circulating miRNAs and granulosa cells was assessed by means of real-time quantitative reverse transcription-polymerase chain reaction analysis. RESULT(S): We identified miRNA-200b and miRNA-429 in the sera of all women tested. These miRNA expression levels were elevated during the early follicular phase of the cycle compared with serum levels during the early luteal phase. Anovulatory women, diagnosed with polycystic ovary syndrome, expressed significantly higher levels of miRNA-200b and miRNA-429 compared with spontaneously ovulating women. Ovulation induction with exogenous gonadotropins during an IVF cycle reduced these levels to the levels measured in normal ovulating women. CONCLUSION(S): Our findings suggest an involvement of miRNA-200b and miRNA-429 in the pituitary regulation of human ovulation. Although it is unclear whether this altered miRNA expression profile is a cause or a result of anovulation, the levels of these molecules in the serum of anovulatory women may serve as serum biomarkers for the ovulation process.

Overexpression of miR-200b inhibits the cell proliferation and promotes apoptosis of human hypertrophic scar fibroblasts in vitro.

Hypertrophic scarring leads to a deformed appearance and contracted neogenetic tissue, resulting in physiological and psychological problems for patients. Millions of people suffer these discomforts each year. Emerging evidence has reported that miRNA contributed to hypertrophic scarring or keloid formation. In this study, nine hypertrophic scar samples and the matched normal skin tissues were used to perform a miRNA microarray. The results of miRNA array showed that miR-200b was downregulated by more than 2-fold, validated by qPCR in hypertrophic scar tissues and human hypertrophic scar fibroblasts, suggesting that there was an important correlation between miR-200b and hypertrophic scarring. We also found that miR-200b affected hypertrophic scarring through regulating the cell proliferation and apoptosis of human hypertrophic scar fibroblasts by affecting the collagen I and III synthesis, fibronectin expression and TGF-ß1/α-SMA signaling. Thus, our study provides evidence to support that miR-200b may be a useful target for hypertrophic scarring management.

microRNA-200b modulates microglia-mediated neuroinflammation via the cJun/MAPK pathway.

Chronic activation of microglia, the macrophages of the CNS, has been shown to enhance neuronal damage because of excessive release of proinflammatory cytokines and neurotoxic molecules in a number of neurodegenerative diseases. Recent reports showed altered microRNA (miRNA) expression in immune-mediated pathologies, thus suggesting that miRNAs modulate expression of genes involving immune responses. This study demonstrates that miRNA-200b is expressed in microglia and modulates inflammatory response of microglia by regulating mitogen-activated protein kinase pathway. miRNA-200b expression was found to be down-regulated in activated microglia in vivo (traumatic brain injury rat model) and in vitro. A luciferase assay and loss- and gain-of-function studies revealed c-Jun, the transcription factor of cJun-N terminal kinase (JNK) mitogen-activated protein kinase pathway to be the target of miR-200b. Knockdown of miR-200b in microglia increased JNK activity along with an increase in pro-inflammatory cytokines, inducible nitric oxide synthase expression and nitric oxide (NO) production. Conversely, over-expression of miRNA-200b in microglia resulted in a decrease in JNK activity, inducible nitric oxide synthase expression, NO production and migratory potential of activated microglia. Furthermore, miR-200b inhibition resulted in increased neuronal apoptosis after treatment of neuronal cells with conditioned medium obtained from microglial culture. Taken together, these results indicate that miRNA-200b modulates microglial inflammatory process including cytokine secretion, NO production, migration and neuronal survival.