MiR-137 affects bone mineral density in osteoporosis rats through regulating RUNX2.

OBJECTIVE: To study the influence of micro ribonucleic acid (miR)-137 on osteoporosis rats by regulating runt-related transcription factor 2 (RUNX2). MATERIALS AND METHODS: A total of 36 Sprague-Dawley rats were randomly assigned to the normal group (n=12), model group (n=12), and inhibitor group (n=12). No treatment was performed in the normal group. The osteoporosis model in rats was prepared in the model group, and miR-137 inhibitor was administered in osteoporosis rats of inhibitor group. Following 12 weeks of intervention, sampling was conducted. The expression of RUNX2 was detected via immunohistochemistry, and its protein expression level was determined via Western blotting. Quantitative Polymerase Chain Reaction (qPCR) was carried out to detect the mRNA level of miR-137. The contents of serum bone Gla protein (BGP) and total alkaline phosphatase (TALP) were measured using enzyme-linked immunosorbent assay (ELISA). Finally, bone mineral density was determined with a dual-energy X-ray absorptiometry instrument. RESULTS: According to the immunohistochemistry detection, the rats in model group and inhibitor group had a notably lower positive expression level of RUNX2 than normal group (p<0.05), and its expression level in the inhibitor group was substantially higher than that in the model group (p<0.05). Western blotting results showed that compared with that in the normal group, the protein expression level of RUNX2 was notably lowered in the model and inhibitor group (p<0.05), which was markedly higher in the inhibitor group than that in the model group (p<0.05). It was found through the qPCR that the expression level of miR-137 was remarkably raised in both model group and inhibitor group compared with that in the normal group, showing statistically significant differences (p<0.05). The rats in the inhibitor group had a remarkably lower expression level of miR-137 than the model group (p<0.05). ELISA results revealed that the model group and inhibitor group had substantially lower contents of serum BGP and TALP than the normal group (p<0.05), and that their contents rose dramatically in the inhibitor group compared with that in the model group (p<0.05). Additionally, based on the measurement of bone mineral density, compared with that in the normal group, bone mineral density declined considerably in the model group and inhibitor group (p<0.05). It was markedly elevated in inhibitor group in comparison with that in the model group (p<0.05). CONCLUSIONS: MiR-137 regulates RUNX2 to affect the bone mineral density of osteoporosis model rats.

LncRNA LINC00707 promotes osteogenic differentiation of hBMSCs through the Wnt/ß-catenin pathway activated by LINC00707/miR-145/LRP5 axis.

OBJECTIVE: Human bone marrow mesenchymal stem cells (hBMSCs) have a strong self-renewal potential and osteogenic differentiation ability, thus providing a new method for bone defect repair research. LncRNA LINC00707 participates in the regulation of osteogenic differentiation of hBMSCs and our aim was to explore the potential regulatory mechanism. MATERIALS AND METHODS: Firstly, quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression levels of LINC00707, miR-145, the low-density lipoprotein receptor-related protein 5 (LRP5) and osteogenesis-related genes. Next, alkaline phosphatase (ALP) activity assay was used to measure the relative activity of ALP in hBMSCs. The protein levels of LRP5 and osteogenesis-related genes were detected by Western blot. Finally, the relationship among LINC00707, miR-145 and LRP5 were predicted by online software and verified by Dual-Luciferase reporter assay, RNA pull-down and RNA immunoprecipitation (RIP). RESULTS: LINC00707 and osteogenesis-related genes were gradually upregulated during osteogenesis of hBMSCs. Meanwhile, overexpression of LINC00707 promoted osteogenic differentiation of hBMSCs. Interestingly, we found that LINC00707 negatively regulated the miR-145 expression and osteogenic differentiation functions by directly interacting with miR-145, and LINC00707 affected the functions of LRP5 by sponging miR-145 in hBMSCs. Moreover, LINC00707 promoted the Wnt/ß-catenin pathway through the LINC00707/miR-145/LRP5 axis. CONCLUSIONS: LncRNA LINC00707 promoted osteogenic differentiation of hBMSCs by targeting LRP5 mediated by miR-145 through the activation of the Wnt/ß-catenin pathway.

The function of spineless in antenna and wing development of the brown planthopper, Nilaparvata lugens.

A wide array of sensilla are distributed on insect antennae, and they play a variety of important roles. Rice planthoppers, destructive pests on rice, have a unique antenna sensilla structure called the 'sensory plaque organ'. The spineless (ss) gene encodes a bHLH-PAS transcription factor and plays a key role in antenna development. In the current study, a 3029 bp full-length cDNA of the Nilaparvata lugens ss gene (Nlss) was cloned, and it encodes 654 amino acid residues. The highest level of Nlss expression was detected in the thorax of fourth-instar nymphs. Knockdown of Nlss in nymphs led to a decrease in the number and size of plaque organs. Moreover, the flagella of the treated insects were poorly developed, wilted, and even dropped off from the pedicel. Nlss-knockdown also resulted in twisted wings in both long-winged and short-winged brown planthoppers. Y-type olfactometer analyses indicated that antenna defects originating from Nlss depletion resulted in less sensitivity to host volatiles. This study represents the first report of the characteristics and functions of Nlss in N. lugens antenna and wing development and illuminates the function of the plaque organ of N. lugens in host volatile perception.

[Regulatory effect of bone marrow mesenchymal stem cells on polarization of macrophages].

Objective: To examine the regulatory effect of bone marrow mesenchymal stem cells (BM-MSCs) on the polarization of bone marrow-derived macrophages, and to provide a theoretical support for the application of mesenchymal stem cells in the treatment of liver fibrosis. Methods: MSCs and macrophages were first isolated from the bone marrow of mice. Macrophages were polarized to M1 macrophages with lipopolysaccharide (LPS) and interferon-γ (IFN-γ), and to M2 macrophages with interleukin-4 (IL-4). The macrophages were then co-cultured with BM-MSCs in a Transwell for 24 h, and changes in the percentages of M1 and M2 macrophages were examined using flow cytometry. The mRNA levels of the M1 macrophage-associated cytokines, tumor necrosis factor-α (TNF-α) and interleukin-23a (IL-23a), and M2 macrophage-associated molecules, arginase-1 (Arg-1) and CD163, were measured by real-time quantitative PCR. The two samples were compared using the t test, and P < 0.05 was considered as statistically significant. Results: Flow cytometry showed that the percentage of M1 macrophages was significantly lower in the (macrophage + LPS + IFN-γ + BM-MSC) co-culture group than in the (macrophage + LPS + IFN-γ) group (62.5% ± 4.6% vs 86.6% ± 6.9%, t = 5.034, P = 0.0073). In addition, the relative mRNA expression of TNF-α and IL-23a was also significantly reduced in the co-culture group compared with those in the macrophage control group as measured by RT-qPCR (t = 11.57 and 10.57, respectively, P < 0.05). Compared with that in the macrophage control group, the percentage of M2 macrophages in the (macrophage+BM-MSC) co-culture group was significantly increased (89.5% ± 5.8% vs 70.1% ± 6.3%, t = 3.924, P = 0.0172), along with significantly elevated relative mRNA expression of Arg1 (14.35±1.05 vs 1.00±0.03, t = 21.96, P < 0.05) and CD163 (3.04 ± 0.27 vs 1.00 ± 0.03, t = 13.14, P < 0.05). Conclusion: BM-MSCs can inhibit LPS + IFN-γ-induced polarization to M1 macrophages and promote polarization to M2 macrophages through the release of paracrine factors.