MiR-210 promotes bone formation in ovariectomized rats by regulating osteogenic/adipogenic differentiation of bone marrow mesenchymal stem cells through downregulation of EPHA2.

PURPOSE: In osteoporosis, the balance between osteogenic and adipogenic differentiation of mesenchymal stem cells (MSCs) is disrupted. The osteogenic differentiation of bone marrow MSCs (BMSCs) is important for improving osteoporosis. The aim of this study was to explore the role and molecular mechanism of miR-210 in the balance of osteogenic/adipogenic differentiation of BMSCs in postmenopausal osteoporosis. METHODS: Postmenopausal osteoporosis rat models were constructed by ovariectomy (OVX). BMSCs were isolated from the femur in rats of Sham and OVX groups. MiR-210 was overexpressed and suppressed by miR-210 mimics and inhibitor, respectively. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the relative mRNA expression of miR-210, ephrin type-A receptor 2 (EPHA2), alkaline phosphatase (ALP), osterix (OSX), osteocalcin (Bglap), Runt-related transcription factor 2 (Runx2), peroxisome proliferator activated receptor gamma, and fatty acid binding protein 4 (FABP4) in each group of rat femoral tissues or BMSCs. Western blot was applied to detect the protein expression level of EPHA2 in rat femoral tissues and cells. Alizarin red S staining and oil red O staining were performed to assess the osteogenic and adipogenic differentiation of BMSCs, respectively. In addition, the targeting relationship between miR-210 and EPHA2 was verified by a dual luciferase gene reporter assay. RESULTS: The expression of miR-210 was significantly reduced in femoral tissues and BMSCs of OVX rats, and its low expression was associated with reduced bone formation. The osteogenic differentiation was enhanced in OVX rats treated with miR-210 mimic. Overexpression of miR-210 in transfected BMSCs was also found to significantly promote osteogenic differentiation and even inhibit adipogenic differentiation in BMSCs, while knockdown of miR-210 did the opposite. Further mechanistic studies showed that miR-210 could target and inhibit the expression of EPHA2 in BMSCs, thus promoting osteogenic differentiation and inhibiting adipogenic differentiation of BMSCs. CONCLUSION: MiR-210 promotes osteogenic differentiation and inhibits adipogenic differentiation of BMSCs by down-regulating EPHA2 expression. As it plays an important role in the osteogenic/adipogenic differentiation of osteoporosis, miR-210 can serve as a potential miRNA biomarker for osteoporosis.

MiR-210 improves postmenopausal osteoporosis in ovariectomized rats through activating VEGF/Notch signaling pathway.

BACKGROUND: To explore the effect and mechanism of action of miR-210 on postmenopausal osteoporosis (PMPO) in ovariectomized rats in vivo. METHODS: An ovariectomized (OVX) rat model was established by ovariectomy. Tail vein injection was performed to overexpress and knock down miR-210 in OVX rats, followed by the collection of blood and femoral tissues from each group of rats. And quantitative real-time polymerase chain reaction (qRT-PCR) was applied to assess the expression level of miR-210 in femoral tissues of each group. Micro computed tomography (Micro CT) was adopted to scan the microstructure of the femoral trabecula in each group to obtain relevant data like bone mineral density (BMD), bone mineral content (BMC), trabecular bone volume fraction (BV/TV), trabecular thickness (Tb.Th), bone surface-to-volume ratio (BS/BV), and trabecular separation (Tb.Sp). ELISA was used for determining the level of bone alkaline phosphatase (BALP), amino-terminal propeptide of type I procollagen (PINP), osteocalcin (OCN), and C-terminal telopeptide of type I collagen (CTX-1) in serum; and Western blot for the protein level of Runt-related transcription factor 2 (Runx2), osteopontin (OPN), and collagen type I alpha 1 (COL1A1) in femoral tissues. RESULTS: MiR-210 expression was significantly decreased in femoral tissues of OVX rats. Overexpression of miR-210 could obviously increase BMD, BMC, BV/TV and Tb.Th, whereas significantly decrease BS/BV and Tb.Sp in femurs of OVX rats. Moreover, miR-210 also downregulated BALP and CTX-1 level, upregulated PINP and OCN level in the serum of OVX rats promoted the expression of osteogenesis-related markers (Runx2, OPN and COL1A1) in the femur of OVX rats. Additionally, further pathway analysis revealed that high expression of miR-210 activated the vascular endothelial growth factor (VEGF)/Notch1 signaling pathway in the femur of OVX rats. CONCLUSION: High expression of miR-210 may improve the micromorphology of bone tissue and modulate bone formation and resorption in OVX rats by activating the VEGF/Notch1 signaling pathway, thereby alleviating osteoporosis. Consequently, miR-210 can serve as a biomarker for the diagnosis and treatment of osteoporosis in postmenopausal rats.

Ginsenoside Rh2 alleviates ulcerative colitis by regulating the STAT3/miR-214 signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Ginseng is a valuable medicinal herb used in China for the prevention and treatment of cancer, diabetes, cardiovascular diseases and other diseases. As the main active ingredient of ginseng, ginsenoside has a wide range of pharmacological effects. Ginsenoside Rh2, a protopanaxadiol saponin from ginseng, exhibits anti-inflammatory and anticancer effects. AIM OF THE STUDY: The potential biological mechanism of Rh2 in the treatment of ulcerative colitis (UC) has not been clarified clearly. In our research, we aimed to explore the therapeutic effects of Rh2 on dextran sodium sulfate (DSS)-induced colitis and elucidate the mechanism of Rh2 in treating UC. METHODS: DSS-induced UC mice were established and randomly divided into the following four groups: control group, DSS group, Rh2 (50 mg/kg) group and sulfasalazine (SASP, 200 mg/kg) group. Except for the control group, 3% DSS drinking water was given to each group for 7 days, and the other two groups were intragastrically administered with Rh2 and SASP for 10 days. At the end of the experiment, colon samples were collected, and phenotypic and pathological analyses were performed in UC mice. Then, Western blot, immunohistochemistry and quantitative real-time PCR analyses were performed to determine the expression of signaling pathway-related factors. RESULTS: Rh2 markedly alleviated DSS-induced body weight loss, intestinal damage, colon length shortening and disease activity index (DAI) scores. Furthermore, proinflammatory cytokines, such as TNF-α, IL-6 and IL-1ß, were reduced by Rh2. Additionally, STAT3/miR-214 activation was also suppressed by Rh2 administration. In vitro, we demonstrated that Rh2 effectively inhibited IL-6-induced STAT3 phosphorylation and miR-214 expression in cultured normal colonic epithelial cells. CONCLUSION: Our results suggested that Rh2 exhibits potential application value in the treatment of UC, and its mechanism is related to the downregulation of STAT3/miR-214 levels, which is expected to be applicable in the treatment of clinical UC.

Limonin ameliorates ulcerative colitis by regulating STAT3/miR-214 signaling pathway.

Ulcerative colitis (UC) is a major inflammatory bowel disease (IBD) which has become a global public health problem. Limonin is a triterpenoid extracted from citrus which possesses the capacities to against inflammations and cell apoptosis. However, the efficacy and the underlying mechanisms of limonin in the treatment of UC remain unclear. In this study, we first investigated the therapeutic effects of limonin on dextran sodiumsulfate (DSS)-induced UC in vivo by examining the changes of disease activity index (DAI), the colon length, the colon histology, and cyto/chemokine levels. We found that limonin markedly reduced DAI, intestinal damages, and the levels of pro-inflammatory cytokines, such as TNF-α and IL-6. In vitro, limonin significantly repressed the productions of pro-inflammatory cytokines in cultured normal colonic epithelial cells. Mechanistically, we demonstrated that limonin improved the prognosis of UC mainly through downregulating p-STAT3/miR-214 levels. Collectively, our results suggested that limonin was a novel therapeutic agent and it was expected to be translated into the clinic to improve the prognosis of UC.

Controllable anchoring of gold nanoparticles to polypyrrole nanofibers by hydrogen bonding and their application in nonenzymatic glucose sensors.

An enzymeless glucose biosensor based on polypyrrole nanofibers-supporting Au nanoparticles (Au/PPyNFs) was investigated in this study. The Au/PPyNFs heterogeneous composite materials were synthesized in-situ via hydrogen bonding interactions for the assembly of polyethyleneimine (PEI) on the surface of polypyrrole nanofibers (PPyNFs). By changing the molar ratio of PPy to HAuCl(4), Au/PPyNFs with different Au loadings were obtained. The morphology and composition of Au/PPyNFs were characterized using SEM, TEM, FTIR, XRD and XPS, respectively. The hybrids exhibited a high electrocatalytic activity toward glucose oxidation, which is prerequisite for the catalysts to be applied in amperometric glucose sensors. By using the nonenzymatic glucose sensor based on Au/PPyNFs, 0.2-13 mM glucose can be detected with a sensitivity of 1.003 µA cm(-2)mM(-1) and a good linearity (R(2)=0.9993) between current density and glucose concentration. The proposed glucose sensor provides a promising strategy to construct fast, sensitive, and anti-interfering amperometric sensors for early diagnosis and prevention of diabetes.