Sulforaphane modulates TGFβ2-induced conjunctival fibroblasts activation and fibrosis by inhibiting PI3K/Akt signaling.

Aim: To examine the effects of sulforaphane on fibrotic changes of transforming growth factor (TGFβ2) induced human conjunctival fibroblast (HConFs).

Methods: HConFs were cultured and divided into control, TGFβ2 (1 ng/mL), sulforaphane and TGFβ2+sulforaphane groups. Cell viability and apoptosis were detected using the MTT and ApoTox-Glo Triplex assay. Cell migration was detected using scratch and Transwell assay. Real-time quantitative PCR method was used to evaluate mRNA expression of TGFβ2, matrix metalloproteinase-2 (MMP2), myosin light chain kinase (MYLK), integrin αV, integrin α5, fibronectin 1 and α-smooth muscle actin (α-SMA). The protein expression of α-SMA, p-PI3K, PI3K, p-Akt, and Akt were detected by Western blot.

Results: The proliferation of HConFs was significantly (<0.05) suppressed by sulforaphane compared to control cells with the increase of the concentration and treatment time. Cell proliferation after 48h incubation was significantly reduced with 100 µmol/L sulforaphane treatment by 17.53% (<0.05). The Transwell assay showed sulforaphane decreased cell migration by 18.73% compared with TGFβ2-induced HConF (<0.05). TGFβ2-induced the increasing expression of fibronectin, type I collagen and α-SMA, and the phosphorylation of PI3K and Akt were all significantly suppressed by sulforaphane pretreatment.

Conclusion: Sulforaphane inhibits proliferation, migration, and synthesis of the extracellular matrix in HConFs, and inhibiting the PI3K/Akt signaling pathway. Sulforaphane could be a potential therapeutic drug for prevention of scar formation in filtering bleb after trabeculectomy.