Premium
Scaffoldless tissue‐engineered cartilage for studying transforming growth factor beta‐mediated cartilage formation
Author(s) -
Chavez Robert D.,
Serra Rosa
Publication year - 2019
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1002/btpr.2897
Subject(s) - cartilage , microbiology and biotechnology , chemistry , sox9 , transforming growth factor , transforming growth factor beta , osteoarthritis , anabolism , biology , anatomy , medicine , pathology , transcription factor , biochemistry , alternative medicine , gene
Abstract Reduced transforming growth factor beta (TGF‐β) signaling is associated with osteoarthritis (OA). TGF‐β is thought to act as a chondroprotective agent and provide anabolic cues to cartilage, thus acting as an OA suppressor in young, healthy cartilage. A potential approach for treating OA is to identify the factors that act downstream of TGF‐β's anabolic pathway and target those factors to promote cartilage regeneration or repair. The aims of the present study were to (a) develop a scaffoldless tissue‐engineered cartilage model with reduced TGF‐β signaling and disrupted cartilage formation and (b) validate the system for identifying the downstream effectors of TGF‐β that promote cartilage formation. Sox9 was used to validate the model because Sox9 is known to promote cartilage formation and TGF‐β regulates Sox9 activity. Primary bovine articular chondrocytes were grown in Transwell supports to form cartilage tissues. An Alk5/TGF‐β type I receptor inhibitor, SB431542, was used to attenuate TGF‐β signaling, and an adenovirus encoding FLAG‐Sox9 was used to drive the expression of Sox9 in the in vitro‐generated cartilage. SB431542‐treated tissues exhibited reduced cartilage formation including reduced thicknesses and reduced proteoglycan staining compared with control tissue. Expression of FLAG‐Sox9 in SB431542‐treated cartilage allowed the formation of cartilage despite antagonism of the TGF‐β receptor. In summary, we developed a three‐dimensional in vitro cartilage model with attenuated TGF‐β signaling. Sox9 was used to validate the model for identification of anabolic agents that counteract loss of TGF‐β signaling. This model has the potential to identify additional anabolic factors that could be used to repair or regenerate damaged cartilage.