TGFβ1 induces hypertrophic change and expression of angiogenic factors in human chondrocytes

The transforming growth factor beta 1 (TGF beta 1) plays an important role in cartilage development. However, whether TGF beta 1 stimulates chondrocyte proliferation and cartilage regeneration in osteoarthritis (OA) remains elusive, especially in the context of different treatment and tissue environments. In the present study, we investigated the role of TGF beta 1 in human chondrocyte culture in vitro, focusing on the morphological change of chondrocytes and the expression of angiogenic factors upon TGF beta 1 stimulation. We found increased expression of biomarkers indicating chondrocyte hypertrophy and the chondrocytes aggregated to form networks when they were treated with TGF beta 1. DNA microarray analysis revealed significantly increased expression of genes related to blood vessel formation in TGF beta 1 treatment group compared to control group. Matrigel assay further demonstrated that chondrocytes had the potential to form network-like structure. These results suggested that TGF beta 1 induces the hypertrophic change of chondrocytes culture in vitro and induce expression of angiogenic biomarkers. Therefore, application of TGF beta 1 for chondrocyte culture in practice should be considered prudentially and targeting TGF beta 1 or relevant receptors to block the signaling pathway might be a strategy to prevent or alleviate progression of osteoarthritis.