Mitochondrial regulation of bone homeostasis via mitochondria transfer [RNA-seq]

Recent studies have demonstrated that mitochondria can be transferred between different cell types to control metabolic homeostasis. However, whether the mitochondria transfer network occurred in the skeletal system or regulate skeletal metabolic homeostasis in vivo is not fully elucidated. Herein, we found that osteolineage cells transfer mitochondria to CD11b+ myeloid, B220+ lymphoid and hematopoietic stem and progenitor cells (HSPCs), of which monocytes/macrophages received the most transferred mitochondria. This process was inhibited by GC treatment contributing to the progression of glucocorticoid-induced osteoporosis (GIOP). Further analysis demonstrated that osteolineage cells transfer mitochondria to osteoclastic lineage cells via Miro1 mediated direct contact, and altered the glutathione metabolism, leading to the ferroptosis of osteoclastic lineage cells, thus inhibiting osteoclast activities. These findings revealed an unappreciated mechanism of mitochondrial regulation of skeletal metabolic homeostasis via mitochondria transfer and provide new insights of the mechanism of GIOP progression.