MiR-1260b protects against LPS-induced degenerative changes in nucleus pulposus cells through targeting TCF7L2.

Nucleus pulposus (NP) cells play a critical role in maintaining intervertebral disc integrity through producing the components of extracellular matrix (ECM). NP cell dysfunction, including senescence and hyper-apoptosis, has been regarded as critical events during intervertebral disc degeneration development. In the present study, we found that Transcription Factor 7-Like 2 (TCF7L2) was overexpressed within degenerative intervertebral disc tissue samples, and TCF7L2 silencing improved lipopolysaccharide (LPS)-induced repression on NP cell proliferation, ECM synthesis, and LPS-induced NP cell senescence. miR-1260b directly targeted TCF7L2 and inhibited TCF7L2 expression. miR-1260b overexpression improved LPS-induced degenerative changes in NP cells; more importantly, TCF7L2 overexpression significantly reversed the effects of miR-1260b overexpression on LPS-stimulated degenerative changes within NP cells. For the first time, we demonstrated the function of the miR-1260b/TCF7L2 axis on the phenotypic maintenance of chondrocyte-like NP cells and ECM synthesis by NP cells under LPS stimulation.

[Effect of substrate concentration on pathogen indicators inactivation during thermophilic anaerobic digestion].

Because excess sludge contains high density of pathogens, it has to be treated to reduce pathogens before being disposed for land application. In this study, the effect of substrate concentration on pathogen inactivation during thermophilic anaerobic digestion was investigated. The results show that, with the increase of substrate concentration, VFAs and cumulative methane production increased. The density of total coliforms in the suspension liquid has a 2.0-3.0 orders of magnitude decline and fecal coliforms has 1.8-3.3 orders of magnitude decline after 28 days thermophilic anaerobic digestion at substrate concentration of 28-84 g x L(-1) and temperature of 55 degrees C. More than 99% of total coliforms and fecal coliforms have been killed after 28 days digestion. Salmonella spp. was not detected in the suspension and solid after anaerobic digestion. When substrate concentration was higher than 45 g x L(-1), the inactivation of total coliforms and fecal coliforms declined.

Pretreatment of rat bone marrow mesenchymal stem cells with a combination of hypergravity and 5-azacytidine enhances therapeutic efficacy for myocardial infarction.

BACKGROUND AND PURPOSE: The in vivo cardiac differentiation and functional effects of unmodified adult bone marrow mesenchymal stem cells (BMSCs) after myocardial infarction (MI) is controversial. Our previous results suggested that hypergravity promoted the cardiomyogenic differentiation of BMSCs, and thus we postulated that ex vivo pretreatment of BMSCs using hypergravity and 5-azacytidine (5-Aza) would lead to cardiomyogenic differentiation and result in superior biological and functional effects on cardiac regeneration of infarcted myocardium. METHODS: We used a rat MI model generated by ligation of the coronary artery. Homogeneous rat BMSCs were isolated, culture expanded, and differentiated into a cardiac lineage by adding hypergravity (2G) for 3 days and 5-Aza (50 lmol/L, 24 h). Rats underwent BMSCs (labeled with DAPI) injection after the infarction and were randomized into five groups. Group A rats received the control medium, Group B rats received unmodified BMSCs, Group C rats received BMSCs treated with hypergravity, Group D rats received BMSCs treated with 5-Aza, and Group E rats received BMSCs treated with 5-Aza and hypergravity (n = 6). RESULTS: After hypergravity and 5-Aza treatment, BMSCs showed positive for the early muscle and cardiac markers GATA-4, MEF-2, and Nkx2-5 with RT-PCR. We also found that hypergravity could enhance the activities of MEF-2 via promoting the nuclear export of HDAC5. The frozen section showed that the implanted BMSCs labeled with DAPI survived and angiogenesis was identified at the implantation site. In Groups B, C, D, and E rats, pre-treated BMSCs colocalized with α-actinin, and Group E rats showed a significantly larger increase in left ventricular function. CONCLUSIONS: The biological ex vivo cardiomyogenic differentiation of adult BMSCs with hypergravity and 5-Aza prior to their transplantation is feasible and appears to improve their in vivo cardiac differentiation as well as the functional recovery in a rat model of the infarcted myocardium.

In vivo osteogenic properties of the composite of periosteal-derived osteoblast and collagen- coated true bone ceramics.

OBJECTIVE: To contrive new ways for repairing bone defects on the basis of the observation of the osteogenic properties of implanted composite made from periosteal-derived osteoblasts (POB) and true bone ceramics (TBC) coated with collagen (TBCc). METHODS: Bovine cancellous bone was calcined and coated with collagen before being mixed with cultured rabbit osteoblast suspension to prepare the composite, which was respectively implanted subcutaneously on the right of the back of BALB/c nude mice and in the muscle pouches in similar sites of rabbits. The control was established by implantation of TBCc in the contralateral sites corresponding to the former implants in both of animals. Samples were obtained from the implant sites 4 weeks later in mice and 8 weeks later in rabbits respectively, and light and electron microscopic observation was performed routinely. RESULTS: A large number of osteoblasts were seen to grow and proliferate within the TBCc-POB composite where cartilage and bone tissues also generated, which was no observed in the control group. CONCLUSION: The osteoblasts in the implanted TBCc-POB composite can survive and develop into cartilage and bone tissues.