Lakshman Singh1,2, Sonia Tyagi1,2, Damian Myers1,2, Gustavo Duque3,4. 1. Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, Level 3 WCHRE, 176 Furlong Road, St. Albans, VIC, 3021, Australia. 2. Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St. Albans, VIC, Australia. 3. Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, Level 3 WCHRE, 176 Furlong Road, St. Albans, VIC, 3021, Australia. gustavo.duque@unimelb.edu.au. 4. Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St. Albans, VIC, Australia. gustavo.duque@unimelb.edu.au.
Abstract
PURPOSE OF REVIEW: Bone marrow fat expresses mixed characteristics, which could correspond to white, brown, and beige types of fat. Marrow fat could act as either energy storing and adipokine secreting white fat or as a source of energy for hematopoiesis and bone metabolism, thus acting as brown fat. However, there is also a negative interaction between marrow fat and other elements of the bone marrow milieu, which is known as lipotoxicity. In this review, we will describe the good and bad roles of marrow fat in the bone, while focusing on the specific components of the negative effect of marrow fat on bone metabolism. RECENT FINDINGS: Lipotoxicity in the bone is exerted by bone marrow fat through the secretion of adipokines and free fatty acids (FFA) (predominantly palmitate). High levels of FFA found in the bone marrow of aged and osteoporotic bone are associated with decreased osteoblastogenesis and bone formation, decreased hematopoiesis, and increased osteoclastogenesis. In addition, FFA such as palmitate and stearate induce apoptosis and dysfunctional autophagy in the osteoblasts, thus affecting their differentiation and function. Regulation of marrow fat could become a therapeutic target for osteoporosis. Inhibition of the synthesis of FFA by marrow fat could facilitate osteoblastogenesis and bone formation while affecting osteoclastogenesis. However, further studies testing this hypothesis are still required.
PURPOSE OF REVIEW: Bone marrow fat expresses mixed characteristics, which could correspond to white, brown, and beige types of fat. Marrow fat could act as either energy storing and adipokine secreting white fat or as a source of energy for hematopoiesis and bone metabolism, thus acting as brown fat. However, there is also a negative interaction between marrow fat and other elements of the bone marrow milieu, which is known as lipotoxicity. In this review, we will describe the good and bad roles of marrow fat in the bone, while focusing on the specific components of the negative effect of marrow fat on bone metabolism. RECENT FINDINGS: Lipotoxicity in the bone is exerted by bone marrow fat through the secretion of adipokines and free fatty acids (FFA) (predominantly palmitate). High levels of FFA found in the bone marrow of aged and osteoporotic bone are associated with decreased osteoblastogenesis and bone formation, decreased hematopoiesis, and increased osteoclastogenesis. In addition, FFA such as palmitate and stearate induce apoptosis and dysfunctional autophagy in the osteoblasts, thus affecting their differentiation and function. Regulation of marrow fat could become a therapeutic target for osteoporosis. Inhibition of the synthesis of FFA by marrow fat could facilitate osteoblastogenesis and bone formation while affecting osteoclastogenesis. However, further studies testing this hypothesis are still required.
Authors: James F Griffith; David K W Yeung; Anil T Ahuja; Carol W Y Choy; Wong Yin Mei; Sherlock S L Lam; T P Lam; Zhen-Yu Chen; Ping C Leung Journal: Bone Date: 2009-03-05 Impact factor: 4.398
Authors: Sung Sik Choe; Jin Young Huh; In Jae Hwang; Jong In Kim; Jae Bum Kim Journal: Front Endocrinol (Lausanne) Date: 2016-04-13 Impact factor: 5.555
Authors: Gabriel M Pagnotti; Maya Styner; Gunes Uzer; Vihitaben S Patel; Laura E Wright; Kirsten K Ness; Theresa A Guise; Janet Rubin; Clinton T Rubin Journal: Nat Rev Endocrinol Date: 2019-06 Impact factor: 43.330
Authors: Mahdi Imani; Ebrahim Bani Hassan; Sara Vogrin; Aaron Samuel Tze Nor Ch'Ng; Nancy E Lane; Jane A Cauley; Gustavo Duque Journal: Calcif Tissue Int Date: 2021-09-13 Impact factor: 4.333