Protein deubiquitinase USP7 is required for osteogenic differentiation of human adipose-derived stem cells

Abstract Background Human adipose-derived stem cells (hASCs) are multipotent progenitor cells with self-renewal capabilities and multilineage differentiation potential, including osteogenesis. Although protein deubiquitinases have been linked to stem cell fate determination, whether protein deubiquitination contributes to lineage commitment during osteogenic differentiation of hASCs remains to be investigated. The objective of this study was to evaluate the effects of the ubiquitin specific protease 7 (USP7) on osteogenic differentiation of hASCs. Methods An osteocalcin promoter driven luciferase reporter system was established to initially discover the potential association between USP7 and hASC osteogenesis. To further characterize the function of USP7 in osteogenic differentiation of hASCs, a combination of in vitro and in vivo experiments were carried out through genetic depletion or overexpression of USP7 using a lentiviral strategy. Moreover, HBX 41,108, a cyanoindenopyrazine-derived deubiquitinase inhibitor of USP7, was utilized at different doses to further examine whether USP7 regulated osteogenic differentiation of hASCs through its enzymatic activity. Results We demonstrated that USP7 depletion was associated with remarkable downregulation of the reporter gene activity. Genetic depletion of USP7 by lentiviral RNAi markedly suppressed hASC osteogenesis both in vitro and in vivo, while overexpression of USP7 enhanced the osteogenic differentiation of hASCs. Notably, chemical blockade via the small molecular inhibitor HBX 41,108 could efficiently mimic the effects of USP7 genetic depletion in a dose-dependent manner. Conclusions Taken together, our study revealed that protein deubiquitinase USP7 is an essential player in osteogenic differentiation of hASCs through its catalytic activity, and supported the pursuit of USP7 as a potential target for modulation of hASC-based stem cell therapy and bone tissue engineering

Adsorption Site Regulations of [W–O]-Doped CoP Boosting the Hydrazine Oxidation-Coupled Hydrogen Evolution at Elevated Current Density

Highlights The [W–O] group with strong adsorption capacity is introduced into CoP to fabricate a bi-functional catalyst towards HER and HzOR. The cell voltage of HzOR coupled electrolyzer with 6W–O–CoP/NF as both anode and cathode catalysts is 1.634 V lower than that of the water splitting system at 100 mA cm−2. A proof-of-concept self-powered H2 production system is assembled to realize the H2 evolution rate of 3.53 mmol cm−2 h−1

Additional file 1: Figure S1. of Protein deubiquitinase USP7 is required for osteogenic differentiation of human adipose-derived stem cells

Western blotting analysis of USP7 expression in hASCs stably expressing FLAG tagged USP7/wild-type (WT) with antibodies against the indicated proteins. (PDF 12 kb