Expression of thrombospondin-1 (TSP-1) and signal-regulatory protein-alpha (SIRPα) by human articular chondrocytes and molecular associations of CD47/IAP

Protein extracts from primary cultures of human articular chondrocytes were separated by SDS-PAGE and immunoblotted with antibodies against TSP-1 and SIRPα. For TSP-1, a 6% gel under reducing conditions was used, whereas for SIRPα, an 8% gel under non-reducing conditions was used. Protein extracts from primary cultures of human articular chondrocytes were immunoprecipitated with antibodies against CD47/IAP and immunoblotted for TSP-1, SIRPα, or α5 integrin. TSP-1, SIRPα, and α5 integrin are identified in non-immunoprecipitated extracts, but only TSP-1 and α5 integrin co-immunoprecipitate with CD47/IAP. IP, immunoprecipitated protein extracts; MW, molecular weight; N, normal human articular chondrocytes; Non IP, non-immunoprecipitated protein extracts; OA, osteoarthritic human articular chondrocytes.<p><b>Copyright information:</b></p><p>Taken from "CD47 associates with alpha 5 integrin and regulates responses of human articular chondrocytes to mechanical stimulation in an model"</p><p>http://arthritis-research.com/content/10/1/R4</p><p>Arthritis Research & Therapy 2008;10(1):R4-R4.</p><p>Published online 10 Jan 2008</p><p>PMCID:PMC2374443.</p><p></p