1. GIT1 contributes to autophagy in osteoclast through disruption of the binding of Beclin1 and Bcl2 under starvation condition.
- Author
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Zhao SJ, Kong FQ, Cai W, Xu T, Zhou ZM, Wang ZB, Xu AD, Yang YQ, Chen J, Tang PY, Wang Q, Cheng L, Luo YJ, Zhou Z, Li LW, Huang YF, Zhao X, Yin GY, Xue MX, and Fan J
- Subjects
- Animals, Fractures, Bone genetics, Fractures, Bone pathology, Humans, Mice, Mice, Knockout, Osteoclasts metabolism, Phosphorylation, Starvation genetics, Starvation pathology, Autophagy genetics, Beclin-1 genetics, Cell Cycle Proteins genetics, GTPase-Activating Proteins genetics, Proto-Oncogene Proteins c-bcl-2 genetics
- Abstract
Approximately 10-15% of all bone fractures do not heal properly, causing patient morbidity and additional medical care expenses. Therefore, better mechanism-based fracture repair approaches are needed. In this study, a reduced number of osteoclasts (OCs) and autophagosomes/autolysosomes in OC can be observed in GPCR kinase 2-interacting protein 1 (GIT1) knockout (KO) mice on days 21 and 28 post-fracture, compared with GIT1 wild-type (GIT1 WT) mice. Furthermore, in vitro experiments revealed that GIT1 contributes to OC autophagy under starvation conditions. Mechanistically, GIT1 interacted with Beclin1 and promoted Beclin1 phosphorylation at Thr119, which induced the disruption of Beclin1 and Bcl2 binding under starvation conditions, thereby, positively regulating autophagy. Taken together, the findings suggest a previously unappreciated role of GIT1 in autophagy of OCs during fracture repair. Targeting GIT1 may be a potential therapeutic approach for bone fractures.
- Published
- 2018
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