The Adaptor Protein p62 Is Involved in RANKL-induced Autophagy and Osteoclastogenesis |
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Authors: | Rui-Fang Li Gang Chen Jian-Gang Ren Wei Zhang Zhong-Xing Wu Bing Liu Yi Zhao Yi-Fang Zhao |
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Institution: | State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology (RFL, GC, JGR, WZ, ZXW, BL, YZ, YFZ) Wuhan University, Wuhan, China;Department of Oral and Maxillofacial Surgery, School & Hospital of Stomatology (GC, ZXW, BL, YFZ) Wuhan University, Wuhan, China;Department of Prosthodontics, School & Hospital of Stomatology (YZ) Wuhan University, Wuhan, China |
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Abstract: | Previous studies have implicated autophagy in osteoclast differentiation. The aim of this study was to investigate the potential role of p62, a characterized adaptor protein for autophagy, in RANKL-induced osteoclastogenesis. Real-time quantitative PCR and western blot analyses were used to evaluate the expression levels of autophagy-related markers during RANKL-induced osteoclastogenesis in mouse macrophage-like RAW264.7 cells. Meanwhile, the potential relationship between p62/LC3 localization and F-actin ring formation was tested using double-labeling immunofluorescence. Then, the expression of p62 in RAW264.7 cells was knocked down using small-interfering RNA (siRNA), followed by detecting its influence on RANKL-induced autophagy activation, osteoclast differentiation, and F-actin ring formation. The data showed that several key autophagy-related markers including p62 were significantly altered during RANKL-induced osteoclast differentiation. In addition, the expression and localization of p62 showed negative correlation with LC3 accumulation and F-actin ring formation, as demonstrated by western blot and immunofluorescence analyses, respectively. Importantly, the knockdown of p62 obviously attenuated RANKL-induced expression of autophagy- and osteoclastogenesis-related genes, formation of TRAP-positive multinuclear cells, accumulation of LC3, as well as formation of F-actin ring. Our study indicates that p62 may play essential roles in RANKL-induced autophagy and osteoclastogenesis, which may help to develop a novel therapeutic strategy against osteoclastogenesis-related diseases. |
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Keywords: | p62 RANKL RAW264 7 cells autophagy osteoclastogenesis |
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