MicroRNAs (miRNAs) emerge as important regulators of stem cell lineage commitment and bone development. MiRNA-26a (miR-26a) is one of the important miRNAs regulating osteogenic differentiation of both bone marrow-derived mesenchymal stem cells (BMSCs) and adipose tissue-derived mesenchymal stem cells (ADSCs). However, miR-26a functions oppositely in osteogenic differentiation of BMSCs and ADSCs, suggesting distinct post-transcriptional regulation of tissue-specific MSC differentiation. However, the molecular basis is largely unknown. Here, we report that the function of miR-26a is largely depended on the intrinsic signaling regulation network of MSCs. Using bioinformatics and functional assay, we confirmed that miR-26a potentially targeted on GSK3β and Smad1 to regulate Wnt and BMP signaling pathway. Overall comparative analysis revealed that Wnt signaling was enhanced more potently and played a more important role than BMP signaling in osteogenic differentiation of BMSCs, whereas BMP pathway was more essential for promoting osteogenic differentiation of ADSCs. The distinct activation pattern and role of signaling pathways determined that miR-26a majorly targeted on GSK3β to activate Wnt signaling for promoting osteogenic differentiation of BMSCs, whereas it inhibited Smad1 to suppress BMP signaling for interfering with the osteogenic differentiation of ADSCs. Taken together, our study demonstrated that BMSCs and ADSCs applied different signaling pathway to facilitate their osteogenic differentiation, which determined the inverse function of miR-26a. The distinct transcriptional regulation and post-transcriptional regulation network suggested the intrinsic molecular differences between tissue-specific MSCs and the complexity in MSC research and MSC-based cell therapy.

Evidence indicates that after brain injury, neurogenesis is enhanced in regions such as hippocampus, striatum, and cortex. To study the role of hypoxia-inducible factor-1 (HIF"‘1α) and Wnt signaling in cerebral ischemia/hypoxia-induced proliferation of neural stem cells (NSCs), we investigated the proliferation of NSCs, expression of HIF"‘1α, and activation of Wnt signaling under conditions of pathologic hypoxia in vitro. NSCs were isolated from 30-day-old Sprague–Dawley rats and subjected to 0.3% oxygen in a microaerophilic incubation system. Cell proliferation was evaluated by measuring the diameter of neurospheres and by bromodeoxyuridine incorporation assays. Real-time quantitative PCR and Western blotting were used to detect mRNA and protein levels of HIF-1α, β-catenin, and cyclin D1 in the NSCs. The results showed that hypoxia increased NSC proliferation and the levels of HIF-1α, β"‘catenin, and cyclin D1 (p < 0.05). Blockade of the Wnt signaling pathway decreased hypoxia-induced NSC proliferation, whereas activation of this pathway increased hypoxia-induced NSC proliferation (p < 0.05). Knockdown of HIF-1α with HIF-1α siRNA decreased β"‘catenin nuclear translocation and cyclin D1 expression, and inhibited proliferation of NSCs (p < 0.05). These findings indicate that pathologic hypoxia stimulates NSC proliferation by increasing expression of HIF-1α and activating the Wnt/β-catenin signaling pathway. The data suggest that Wnt/β-catenin signaling may play a key role in NSC proliferation under conditions of pathologic hypoxia.

Few studies have evaluated health-related quality of life (HRQoL) of patients with chronic hepatitis B (CHB) in mainland China. We aimed at characterizing the impact of CHB on HRQoL in mainland Chinese and finding out factors associated with HRQoL. 460 CHB patients (323 with CHB only, 54 with compensated cirrhosis and 83 with decompensated cirrhosis) and 460 pair-matched healthy controls were recruited in Xi'an city. They answered a structured questionnaire including the Short Form 36 version 2 (SF-36v2), the Chronic Liver Disease Questionnaire (CLDQ) (only for patients), and questions on socio-demographic and clinical characteristics. A blood sample was collected from each of patients for liver function tests. SF-36v2 scores were compared between patients and controls overall and by groups by paired-samples t-test, and CLDQ scores and paired differences of SF-36v2 scores were compared among three patient groups by one-way ANOVA or Kruskal-Wallis test. Multi-variable linear regression analyses were performed to identify determinants of HRQoL in patients. Patients, overall and by groups had significantly lower SF-36v2 scores than controls on all summaries and domains, with differences higher than the suggested minimally important difference values. Both the SF-36v2 and the CLDQ showed that HRQoL of patients with cirrhosis further deteriorated, but compensated and decompensated cirrhosis patients had similar total HRQoL impairments. The gradually increasing impairment with disease progression was confirmed only on physical components. Impaired liver function and currently taken anti-viral treatment were associated with lower HRQoL. Education attainment and annual per capita household income had a positive effect on HRQoL. Mainland Chinese CHB patients suffered significant HRQoL impairment on all health dimensions, and the impairment reached a high level on mental health at initial stage of illness and increased gradually on physical health with disease progression. Attention should be paid to the reduction of patients' treatment cost burden and the provision of early health education accompanied with proper treatments.