Overexpression of murine small heat shock protein HSP25 interferes with chondrocyte differentiation and decreases cell adhesion.
Although multiple functions for the small heat shock protein HSP25 have been proposed, its specific role during developmental and differentiation processes is not known. Cartilage is one of the tissues in which HSP25 is specifically and highly expressed during development. C1 cells, able to form aggregates in vitro, can be induced to differentiate into chondrocytes. In this study, we generated two stable transfected clones overexpressing HSP25 at two different levels. Cell morphology and growth rate were modified in both clones, although the actin content and distribution did not seem to be altered. Overexpressing clones had more difficulties in coalescing, leading to smaller aggregates and they did not differentiate into chondrocytes. Subsequently, these aggregates tended to dissociate into loose masses of dying cells. The strength of all these effects was directly correlated to the level of HSP25 overexpression. These data suggest that overexpressing HSP25 decreases cellular adhesion and interferes with chondrocyte differentiation.
Favet
N
N
Unité de Génétique Moléculaire, Ecole Normale Supérieure, 46, rue d'Ulm, 75230 Paris, Cedex 05, France.
Duverger
O
O
Loones
M T
MT
Poliard
A
A
Kellermann
O
O
Morange
M
M
D008841:Actin Cytoskeleton / Q000378:metabolism; D000818:Animals; D002448:Cell Adhesion; D002454:Cell Differentiation; D002455:Cell Division; D048429:Cell Size; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism*; D002999:Clone Cells / Q000166:cytology / Q000378:metabolism; D003094:Collagen / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D006360:Heat-Shock Proteins; D015151:Immunoblotting; D007150:Immunohistochemistry; D051379:Mice; D018832:Molecular Chaperones; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D014407:Tumor Cells, Cultured
D006360:Heat-Shock Proteins; C486113:Hsbp1 protein, mouse; D018832:Molecular Chaperones; D009363:Neoplasm Proteins; D003094:Collagen; D005978:Glutathione