p38 MAPK is involved in TGF-&beta1-induced biglycan in HPDL cells

Biglycan, a small leucine-rich proteoglycans, is functionally involved in matrix assembly and plays a crucial role in bone metabolism and mechanical properties. Objectives: The purpose of this study was to determine the pathway of transforming growth factor-beta1 (TGF-b1) in regulating biglycan expression in human periodontal ligament (HPDL) cells. Methods: HPDL cells were treated with TGF-b1 and the expression of biglycan mRNA was detected by RT-PCR. Western blot analysis was used to examine the phosphorylation of smad2/3 and p38 MAPK. Role of p38 kinase in mediating biglycan expression was determined with SB203580, a specific inhibitor for the p38 MAPK. Results: TGF-b1 induced biglycan expression in HPDL cells. Together with the phosphorylated smad2/3, phosphorylated p38 was observed after activated with TGF-b1. Treatment with SB203580 before addition of TGF-b1also made a significant decrease in biglycan expression. Conclusion: These results suggest that p38 MAPK is involved in the upregulation of biglycan by TGF-b1 in HPDL cells.