3.5 | Treatment with TGF-β1 increased MG53, TGF-β1, Col-a1, and ZO-1 expression, whereas treatment with TGF-β1 inhibitor decreased the expression
In vitro cytokine stimulation experiments were conducted to verify the regulatory relationship between MG53 and the TGF-β1/Smad pathway. We found that TGF-β1 stimulation increased the expression of MG53, TGF-β1, Col-a1, and ZO-1, whereas TGF-β1 inhibitor treatment decreased the expression in HNECs (Fig. 5A). The results of western blot and qRT-PCR analyses showed that MG53, TGF-β1, Smad2/3, ZO-1, and Col-a1 were significantly increased after TGF-β1 stimulation, but decreased after treatment with TGF-β1 inhibitor in HNECs of CRSwNP (Fig. 5B–C). The results of immunofluorescence analysis of ZO-1 showed that the mean fluorescence intensity was significantly enhanced by TGF-β1, but decreased upon TGF-β1 inhibitor treatment. Ad-MG53 did not cause significant enhancement in the mean fluorescence intensity of ZO-1 (Fig. 5D).