Astragalus polysaccharide ameliorates steroid-induced osteonecrosis of the femoral head by regulating miR-200b-3p-mediated Wnt/ß-catenin signaling pathway via inhibiting SP1 expression : Astragalus polysaccharide regulates SONFH via SP1.

BACKGROUND: Steroid-induced osteonecrosis of the femoral head (SONFH) is the necrosis of the femur bone caused by prolonged and massive use of corticosteroids. The present study probed into the significance of Astragalus polysaccharide (APS) in SONFH progression. METHODS: SONFH cell model was constructed using murine long bone osteocyte Y4 (MLO-Y4) cells and then treated with APS. mRNA microarray analysis selected differentially expressed genes between control group and SONFH group. RT-qPCR determined SP1 and miR-200b-3p expression. Levels of SP1, ß-catenin, autophagy-related proteins (LC3II/LC3I, Beclin1, p62) and apoptosis-related proteins (Bax, C-caspase3, C-caspase9, Bcl-2) were tested by Western blot. ChIP and luciferase reporter assays confirmed relationship between SP1 and miR-200b-3p. Fluorescence intensity of LC3 in cells was detected by immunofluorescence. Flow cytometry assessed cell apoptosis. Osteonecrosis tissues from SONFH mice were examined by HE and TRAP staining. RESULTS: APS induced autophagy and suppressed apoptosis in SONFH cell model. APS inhibited SP1 expression and SP1 overexpression reversed effects of APS on SONFH cell model. Mechanistically, SP1 targeted miR-200b-3p to inhibit Wnt/ß-catenin pathway. MiR-200b-3p depletion rescued the promoting effect of SP1 on SONFH cell model by activating Wnt/ß-catenin pathway. HE staining showed that APS treatment reduced the empty lacunae and alleviated inflammation in trabecular bone of SONFH mice. TRAP staining revealed decreased osteoclasts number in SONFH mice after APS treatment. CONCLUSION: APS regulated osteocyte autophagy and apoptosis via SP1/miR-200b-3p axis and activated Wnt/ß-catenin signaling, thereby alleviating SONFH, shedding new insights for therapy of SONFH.

Advanced nitrogen removal from municipal wastewater treatment plant secondary effluent using a deep bed denitrification filter.

With the improvement of wastewater discharge standards, wastewater treatment plants (WWTPs) are continually undergoing technological improvements to meet the evolving standards. In this study, a quartz sand deep bed denitrification filter (DBDF) was used to purify WWTP secondary effluent, utilizing high nitrate nitrogen concentrations and a low C/N ratio. Results show that more than 90% of nitrate nitrogen (NO3-N) and 75% of chemical oxygen demand (COD) could be removed by the 20th day of filtration. When the filter layer depth was set to 1,600 mm and the additional carbon source CH3OH was maintained at 30 mg L-1 COD (20 mg L-1 methanol), the total nitrogen (TN) and COD concentrations of DBDF effluent were stabilized below 5 and 30 mg L-1, respectively. Analysis of fluorescence revealed that DBDF had a stronger effect on the removal of dissolved organic matter (DOM), especially of aromatic protein-like substances. High throughput sequencing and qPCR results indicate a distinctly stratified microbial distribution for the main functional species in DBDF, with quartz sand providing a good environment for microbes. The phyla Proteobacteria, Bacteroidetes, and Chloroflexi were found to be the dominant species in DBDF.

Astragalus polysaccharide ameliorates steroid-induced osteonecrosis of femoral head through miR-206/HIF-1α/BNIP3 axis.

Declining autophagy and rising apoptosis are the main factors driving the development of steroid-induced osteonecrosis of the femoral head (SONFH). Here, we showed that astragalus polysaccharide (APS) improved femoral head necrosis via regulation of cell autophagy and apoptosis through microRNA (miR)-206/hypoxia inducible factor-1 (HIF-1α)/BCL2 interacting protein 3 (BNIP3) axis. The expression of miR-206, HIF-1α, and BNIP3 in SONFH specimens and cell model were measured using qPCR. SONFH cell model was treated with APS. Cell autophagy was evaluated using LC3-immunofluorescence assays. Flow cytometry was conducted to assess cell apoptosis. Apoptosis-related proteins and autophagy-related proteins were determined using western blot. Besides, dual-luciferase reporter assay was employed to investigate the relationship between miR-206 and HIF-1α. Here we showed that miR-206 expression was upregulated in SONFH tissues and cell model. APS promoted autophagy and inhibited apoptosis in SONFH cell model via downregulating miR-206. What is more, HIF-1α was the target of miR-206. Knockdown of HIF-1α reversed the recovery effect of miR-206 inhibitor on SONFH cell model. Furthermore, BNIP3 was the target of HIF-1α. HIF-1α overexpression promoted autophagy and inhibited apoptosis, and knockdown of BNIP3 abolished the recovery effect of HIF-1α overexpression in SONFH cell model. These results provided evidence that APS reduced miR-206 expression, and the downregulated miR-206 increased BNIP3 expression by targeting HIF-1α to promote autophagy and inhibit bone cell apoptosis. Our research proved that APS effectively improved SONFH by regulating cell autophagy and apoptosis.

A pilot-scale deep bed denitrification filter for secondary effluent treatment using sodium acetate as external carbon.

A pilot-scale quartz sand deep bed denitrification filter (DBDF) using sodium acetate as the additional carbon source was implemented to treat secondary effluent, with a high nitrate nitrogen (NO3 -N) concentration and low C/N ratio, from an urban municipal water resource recovery facility. By the 18th day, results showed that the removal efficiency of NO3 -N and the chemical oxygen demand (COD) were stable at above 85% and 70%, respectively. When the filter layer depth was set to 1,600 mm and the concentration of additional sodium acetate was maintained at 51 mg/L, the total nitrogen and COD concentrations of the DBDF effluent were stabilized below 5 and 30 mg/L, respectively. The quartz sand DBDF had a good effect on the removal of dissolved organic matter, especially for aromatic protein-like and tryptophan protein-like substances. Bacteria with denitrification function, such as Cloacibacterium and Zoogloea, became increasingly dominant with increasing filling layer depth. PRACTITIONER POINTS: The denitrification filter had a good effect on the removal of aromatic protein-like and tryptophan protein-like substances. Cloacibacterium and Zoogloea became increasingly dominant with increasing filling layer depth.