Biological Effects And Gene Expression Of Low-intensity Pulsed Ultrasound On Chondrocytes Of Rabbit Cultured In Alginate Beads

Objective: To explore the effects of low-intensity pulsed ultrasound(LIPUS) on chondrocyte viability, proliferation, phenotype , function and gene expression of col-II,aggrecan,TGF-β1,TIMP-1,MMP-1mRNA,which control and/or regulate cartilage repaire.Method: LIPUS was applied to chondrocyte from 10 New Zealand rabbits cultured in alginate beads ,whose morphology, viability and proliferation was observed every day. The synthesis and secretion of Col-II, Col-I, Col-X and glycosaminoglycans(GAG) were tested through immunohistochemistry and AB-PAS method, while the gene mRNA expression of aggrecan,Collagen II,Collagen I,Collagen X,TGF-β1,MMP1 and TIMP-1 through Realtime PCR.Results: Ultrasound treatment increased chondrocytes proliferation and remained the phenotype but did not affect the cell viability, improved the synthesis and secretion of Col-II, Col-I and glycosaminoglycans(GAG) but inhibited the the synthesis and secretion of Col-X, which might be realized by upregulating the gene mRNA expression of Collagen II aggrecan mRNA,TIMP-1 and TGF-β1 and downregulating the gene mRNA expression of MMP-1 and Collagen X.Conclusions: With the potential ability of repairing articular cartilage, LIPUS has significant positive effects on remaining chondrocytes viability, proliferation and phenotype and increasing synthesis and preventing degeneration of extra cellular matrix ,which may be mediated by upregulating the gene mRNA expression of TGF-β1.