HSP90β promotes osteoclastogenesis by dual-activation of cholesterol synthesis and NF-κB signaling

• Published in: Cell death and differentiation Vol. 30; no. 3; pp. 673 - 686
• Main Authors: Cheng, Hui-Min, Xing, Mingming, Zhou, Ya-Ping, Zhang, Weitao, Liu, Zeyu, Li, Lan, Zheng, Zuguo, Ma, Yuanchen, Li, Pingping, Liu, Xiaoxuan, Li, Ping, Xu, Xiaojun
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.03.2023; Nature Publishing Group
• Subjects: 38/89; 692/308/153; 692/699/2743; 96; 96/95; Animals; Apoptosis; Biochemistry; Biomedical and Life Sciences; Bone loss; Bone marrow; Cell Biology; Cell Cycle Analysis; Cell growth; Cholesterol; Cholesterol - metabolism; Female; Fractures; Genes; Heat shock proteins; Kinases; Laboratories; Life Sciences; Metabolism; Mice; Mice, Inbred C57BL; NF-kappa B - metabolism; NF-κB protein; Osteoclastogenesis; Osteoclasts - metabolism; Osteogenesis - genetics; Osteoporosis; Ovariectomy; Proteasomes; RANK Ligand - metabolism; Signal Transduction; Stem Cells; Ubiquitin
• ISSN: 1350-9047; 1476-5403
• DOI: 10.1038/s41418-022-01071-3

Heat shock protein 90β (Hsp90β, encoded by Hsp90ab1 gene) is the most abundant proteins in the cells and contributes to variety of biological processes including metabolism, cell growth and neural functions. However, genetic evidences showing Hsp90β in vivo functions using tissue specific knockout mice are still lacking. Here, we showed that Hsp90β exerted paralogue-specific role in osteoclastogenesis. Using myeloid-specific Hsp90ab1 knockout mice, we provided the first genetic evidence showing the in vivo function of Hsp90β. Hsp90β binds to Ikkβ and reduces its ubiquitylation and proteasomal degradation, thus leading to activated NF-κB signaling. Meanwhile, Hsp90β increases cholesterol biosynthesis by activating Srebp2. Both pathways promote osteoclastogenic genes expression. Genetic deletion of Hsp90ab1 in osteoclast or pharmacological inhibition of Hsp90β alleviates bone loss in ovariectomy-induced mice. Therefore, Hsp90β is a promising druggable target for the treatment of osteoporosis.