Leukemia inhibitory factor: a paracrine mediator of bone metabolism.
Leukemia inhibitory factor (LIF) is a soluble interleukin-6 family cytokine that regulates a number of physiologic functions, including normal skeletal remodeling. LIF signals through the cytokine co-receptor glycoprotein-130 in complex with its cytokine-specific receptor [LIF receptor (LIFR)] to activate signaling cascades in cells of the skeletal system, including stromal cells, chondrocytes, osteoblasts, osteocytes, adipocytes, and synovial fibroblasts. LIF action on skeletal cells is cell-type specific, and frequently dependent on the state of cell differentiation. This review describes the expression patterns of LIF and LIFR in bone, their regulation by physiological and inflammatory agents, as well as cell-specific influences of LIF on osteoblast, osteoclast, chondrocyte, and adipocyte differentiation. The actions of LIF in normal skeletal growth and maintenance, in pathological states (e.g. autocrine tumor cell signaling and growth in bone) and inflammatory conditions (e.g. arthritis) will be discussed, as well as the signaling pathways activated by LIF and their importance in bone formation and resorption.
St Vincent's Institute of Medical Research, Melbourne, Victoria 3065, Australia. nsims@svi.edu.au
Natalie A
NA
Sims
Rachelle W
RW
Johnson
D000818:Animals; D001847:Bone Diseases / Q000378:metabolism*; D001842:Bone and Bones / Q000166:cytology / Q000378:metabolism* / Q000473:pathology / Q000502:physiology; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism; D050822:Cytokine Receptor gp130 / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D053605:Leukemia Inhibitory Factor / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D053680:Leukemia Inhibitory Factor Receptor alpha Subunit / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism; D010012:Osteogenesis / Q000187:drug effects*
C494199:IL6ST protein, human; C507837:LIF protein, human; C507840:LIFR protein, human; D053605:Leukemia Inhibitory Factor; D053680:Leukemia Inhibitory Factor Receptor alpha Subunit; D050822:Cytokine Receptor gp130