BMP-5 expression increases during chondrocyte differentiation in vivo and in vitro and promotes proliferation and cartilage matrix synthesis in primary chondrocyte cultures
MacKay, Carole A.
Odgren, Paul R.
UMass Chan AffiliationsDepartment of Pathology
Department of Orthopedics
Department of Cell Biology
Graduate School of Biomedical Sciences
KeywordsAnimals; Bone Morphogenetic Protein 5; Bone Morphogenetic Proteins; Calcification, Physiologic; Cartilage, Articular; Cell Differentiation; *Cell Proliferation; Cells, Cultured; Chondrocytes; Extracellular Matrix; Glycosaminoglycans; Immunohistochemistry; Rats; Ribs
Medicine and Health Sciences
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AbstractBone morphogenetic proteins (BMPs) play pivotal roles in bone and cartilage growth and repair. Through phenotypes of short-ear (se) mice, which have BMP-5 mutations, a role for BMP-5 in some specific aspects of skeletogenesis and cartilage growth is known. This report examines BMP-5 expression in the growth plate and in differentiating cultures of primary chondrocytes, and the effects of addition of BMP-5 or its inhibition by anti-BMP-5 antibody in chondrocyte cultures. By laser capture microdissection and immunohistochemistry, we found that BMP-5 is expressed in proliferating zone (PZ) chondrocytes and that the expression increases sharply with hypertrophic differentiation. A similar pattern was observed in differentiating cultures of primary chondrocytes, with BMP-5 expression increasing as cells differentiated, in contrast to other BMPs. BMP-5 added to cultures increased cell proliferation early in the culture period and also stimulated cartilage matrix synthesis. Also, BMP-5 addition to the cultures activated phosphorylation of Smad 1/5/8 and p38 MAP kinase and caused increased nuclear accumulation of phospho-Smads. Anti-BMP-5 antibody inhibited the endogenous BMP-5, reducing cell proliferation and phospho-Smad nuclear accumulation. Together, the results demonstrate that BMP-5 is normally an important regulator of chondrocyte proliferation and differentiation. Whether other BMPs may compensate in BMP-5 loss-of-function mutations is discussed.
SourceJ Cell Physiol. 2008 Jan;214(1):56-64. Link to article on publisher's site
Permanent Link to this Itemhttp://hdl.handle.net/20.500.14038/32841
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