lncRNA SNHG1 attenuates osteogenic differentiation via the miR­101/DKK1 axis in bone marrow mesenchymal stem cells.

The imbalance induced by inhibition of bone mesenchymal stem cell (BMSC) osteogenic differentiation results in osteoporosis (OP); however, the underlying regulatory mechanism is not completely understood. Long non­coding RNAs (lncRNAs) serve crucial roles in osteogenic differentiation; therefore, investigating their regulatory role in the process of osteogenic differentiation may identify a promising therapeutic target for OP. The expression of small nucleolar RNA host gene 1 (SNHG1), Dickkopf 1 (DKK1), microRNA (miR)­101, RUNX family transcription factor 2 (RUNX2), osteopontin (OPN) and osteocalin (OCN) were detected via reverse transcription­quantitative PCR. The protein expression levels of DKK1, ß­catenin, RUNX2, OPN, OCN, osterix and collagen type I α1 chain were analyzed by performing western blotting. The osteoblastic phenotype was assessed by conducting alkaline phosphatase activity detection and Alizarin Red staining. The interaction between SNHG1 and miR­101 was validated by bioinformatics and luciferase assays. The regulatory role of SNHG1 in BMSC osteogenic differentiation was assessed. SNHG1 expression was downregulated in a time­dependent manner during the process of osteogenic differentiation. SNHG1 overexpression inhibited osteogenic differentiation compared with the pcDNA group. The results indicated that SNHG1 and DKK1 directly interacted with miR­101. Moreover, SNHG1 regulated the Wnt/ß­catenin signaling pathway to inhibit osteogenic differentiation via the miR­101/DKK1 axis. The present study indicated that lncRNA SNHG1 could attenuate BMSC osteogenic differentiation via the miR­101/DKK1 axis as a competitive endogenous RNA. Therefore, the present study furthered the current understanding of the potential mechanism underlying lncRNAs in in osteogenic differentiation.

Structural characterization and antioxidant effect of green alga Enteromorpha prolifera polysaccharide in Caenorhabditis elegans via modulation of microRNAs.

A water-soluble heteropolysaccharide was isolated and purified from Enteromorpha prolifera by DEAE-52 and Bio-Gel P-2 column chromatography. Fourier transform infrared spectroscopy (FTIR), high performance liquid chromatography (HPLC), multi-angle laser light scattering (MALLS), and nuclear magnetic resonance (NMR) spectroscopy were used to characterize the structure of E. prolifera polysaccharide degradation (EPP-1). Its anti-oxidative activity was determined in Caenorhabditis elegans via modulation of microRNAs. The average molecular weight of EPP-1 was 4.28 kDa. It contained six types of linkage units as →2)-ß-d-GlcpA-(1→, →3,6)-ß-d-Manp-(1→, →4)-α-d-Glcp-(1→, →6)-ß-d-Galp-(1→, ß-l-Rhap-(1→, and →4)-ß-d-GalpA-(1→. The mean lifespan, ultraviolet-induced oxidative stress, and thermotolerance in C. elegans were improved after treatment of EPP-1. Moreover, EPP-1 significantly increased the total superoxide dismutase levels and decreased the malondialdehyde levels in C. elegans. Intracellular reactive oxygen species accumulation and DNA damage were ameliorated by up-regulation of SKN-1 and DAF-16 expression through miR-48 and miR-51 miR-186 down-regulation. In vivo studies demonstrated that EPP-1 might be applied in functional foods as the antioxidative and anti-ageing ingredient.

[Effects of positive end expiratory pressure on pulmonary surfactant in patients undergoing one-lung ventilation].

OBJECTIVE: To evaluate the effect of positive end expiratory pressure on the bronchoalveolar lavage fluid (BALF) in pulmonary surfactant (PS) of patient during one lung ventilation anesthesia. METHODS: Patients undergoing Bullae resection were anesthetized with treatment (n = 12) or control (n = 12) combined anesthesia. Total phospholipid (TPL), saturated phosphatidylcholine (SatPC) and total protein (TP) in the bronchoalveolar lavage fluid (BALF) were measure. The ratio of SatPC/TPL% and SatPC/TP% represented the activity of PS. RESULTS: The thoracic surgery pulmonary surfactant significantly reduced, PEEP can prevent the decrease, but with decreased cardiac output. CONCLUSION: The end-expiratory pressure breathing can maintain the level of pulmonary surfactant to protect lung function.

Activation of aminoflavone (NSC 686288) by a sulfotransferase is required for the antiproliferative effect of the drug and for induction of histone gamma-H2AX.

Aminoflavone (AF) is entering clinical trials. We recently reported that AF induces DNA-protein cross-links (DPC) and gamma-H2AX in MCF-7 human breast cancer cells. To elucidate the mechanism of action of AF and provide biomarkers indicative of AF activity, we correlated AF activity profile (GI(50)) with gene expression patterns in the NCI-60 cell lines. Sulfotransferases (SULT) showed the highest positive correlation coefficients among approximately 14,000 probe sets analyzed (r = 0.537, P < 0.001). Stable transfection of SULT1A1 into AF-resistant MDA-MB-231 cells sensitized these cells to AF. AF produced DPCs, gamma-H2AX foci, and S-phase arrest in the SULT1A1-transfected but not in the parent MDA-MB-231 cells. Conversely, cells in which SULT1A1 was knocked down by small interfering RNA failed to induce gamma-H2AX. Inhibition of SULTs and cytochrome P450 (CYP) enzymes by natural flavonoids blocked the antiproliferative activity of AF and the formation of AF-DNA adducts. AF also induces SULT1A1 and CYP expression in MCF-7 cells, suggesting the existence of an aryl hydrocarbon receptor-mediated positive feedback for AF activation by CYP and SULT1A1. Metabolism studies showed that AF can be oxidized by CYP at two amino groups to form N-hydroxyl metabolites that are substrates for bioactivation by SULTs. We propose that both N-sulfoxy-groups can be further converted to nitrenium ions that form adducts with DNA and proteins. The results reported here show the importance of SULT1A1 and CYP for AF activation and anticancer activity. They also suggest using SULT1A1 and gamma-H2AX as biomarkers for prediction of AF activity during patient selection and monitoring of clinical trials.