The mechanism of TGF-β mediating BRD4/STAT3 signaling pathway to promote fibroblast proliferation and thus promote keloid progression

The purpose of this study was to investigate the effect of TGF-β on keloid and its molecular mechanism in fibroblasts.

Methods: The difference between normal tissue and keloid tissue can be detected using HE staining. Fibroblasts were treated with TGF-β, and then treated with the BRD4 inhibitor JQ1 and the STAT3 activator Colivelin TFA. Western blot was used to measure the relative protein expression of TGF-β, BRD4, p-STAT3, p-EZH2, C-myc, KLF2, KLF4, α-SMA, and Collagen-I. Immunofluorescence staining was used to measure the relative fluorescence intensity of BRD4, p-STAT3, α-SMA, and Collagen-I. Cell proliferation ability was evaluated by CCK-8 assay and colony formation assay.

Results: The expression of TGF-β and BRD4 was significantly higher in keloid tissue compared to normal tissue. TGF-β mediated the BRD4/STAT3 signaling pathway to inhibit p-EZH2 and promote the expression of C-myc, KLF2, KLF4, α-SMA, and Collagen-I. Additionally, TGF-β mediated the BRD4/STAT3 signaling pathway to enhance fibroblast proliferation.

Conclusion: TGF-β mediates the BRD4/STAT3 signaling pathway to promote fibroblast proliferation and contribute to the progression of keloid.