Objectives Dysregulated osteoclast function contributes to skeletal diseases.However,the specific ubiquitination regulators of the osteoclastogenesis repressor MafB,particularly at the post-translational level,remain ...Objectives Dysregulated osteoclast function contributes to skeletal diseases.However,the specific ubiquitination regulators of the osteoclastogenesis repressor MafB,particularly at the post-translational level,remain undefined.This study aims to identify ubiquitin-specific proteases(USPs)that deubiquitinate MafB and enhance its stability.Methods We constructed a MafB-conjugated luciferase and overexpressed 40 individual USPs,measuring changes in luciferase activity.The identified USP was overexpressed in human CD14^(+) peripheral blood mononuclear cells(PBMCs)to evaluate its effect.Osteoclast differentiation was assessed through osteoclast marker Integrin alpha-V(CD51)staining and Western blot analysis.Co-immunoprecipitation(co-IP)was performed to assess the interplay.The influence on MafB ubiquitination and degradation was evaluated via immunoprecipitation and Western blot.Finally,MafB was knocked down in the USP-overexpressing PBMCs to analyze its effect on osteoclast differentiation.Results Overexpression of ubiquitin-specific protease 29(USP29)significantly increased MafB expression by approximately 75%(p<0.0001).Elevated USP29 levels strongly inhibited osteoclastic differentiation in CD14^(+) PBMCs(p<0.0001).USP29 was found to interact with MafB,markedly reducing its ubiquitination and subsequent degradation in PBMCs(p<0.001).Knocking down MafB in USP29-overexpressing PBMCs alleviated the inhibitory effect of USP29 on osteoclastogenesis.Conclusion USP29 acts as a potent stabilizer of MafB,inhibiting osteoclastogenesis in human CD14^(+) PBMCs,at least in part,by enhancing MafB stability.These findings expand our understanding of USP29’s role and the post-translational regulation of MafB.Furthermore,USP29 serves as a vital factor that controls osteoclast differentiation,and its regulatory function is at least partially mediated by deubiquitinating and stabilizing MafB.展开更多
文摘Objectives Dysregulated osteoclast function contributes to skeletal diseases.However,the specific ubiquitination regulators of the osteoclastogenesis repressor MafB,particularly at the post-translational level,remain undefined.This study aims to identify ubiquitin-specific proteases(USPs)that deubiquitinate MafB and enhance its stability.Methods We constructed a MafB-conjugated luciferase and overexpressed 40 individual USPs,measuring changes in luciferase activity.The identified USP was overexpressed in human CD14^(+) peripheral blood mononuclear cells(PBMCs)to evaluate its effect.Osteoclast differentiation was assessed through osteoclast marker Integrin alpha-V(CD51)staining and Western blot analysis.Co-immunoprecipitation(co-IP)was performed to assess the interplay.The influence on MafB ubiquitination and degradation was evaluated via immunoprecipitation and Western blot.Finally,MafB was knocked down in the USP-overexpressing PBMCs to analyze its effect on osteoclast differentiation.Results Overexpression of ubiquitin-specific protease 29(USP29)significantly increased MafB expression by approximately 75%(p<0.0001).Elevated USP29 levels strongly inhibited osteoclastic differentiation in CD14^(+) PBMCs(p<0.0001).USP29 was found to interact with MafB,markedly reducing its ubiquitination and subsequent degradation in PBMCs(p<0.001).Knocking down MafB in USP29-overexpressing PBMCs alleviated the inhibitory effect of USP29 on osteoclastogenesis.Conclusion USP29 acts as a potent stabilizer of MafB,inhibiting osteoclastogenesis in human CD14^(+) PBMCs,at least in part,by enhancing MafB stability.These findings expand our understanding of USP29’s role and the post-translational regulation of MafB.Furthermore,USP29 serves as a vital factor that controls osteoclast differentiation,and its regulatory function is at least partially mediated by deubiquitinating and stabilizing MafB.
