Gene transfer of Smad7 modulates injury-induced conjunctivalwound healing in mice

[摘要] Purpose: Smad7 is a molecule that blocks the Smad2/3 signal. Herein,we examined the effects of Smad7 gene introduction on post-injuryconjunctival wound healing in mice. Its effects on the cultured humansubconjunctival fibroblasts (SCFs) were also investigated.Methods: A circumferential incision was made in the equatorialconjunctiva by using scissors in the right eye of fully anesthetizedadult C57BL/6 mice (n=72). Smad7 cDNA-expressing adenoviral vector wastopically applied. The control eye received nonfunctioning adenoviralvector. After 2, 5, 7, and 30 days the eyes were processed forhistological or immunohistochemical examination to evaluate woundhealing of conjunctiva. The expressions of type-I collagen and growthfactors were evaluated by real time-reverse transcriptase-polymerasechain reaction. The effects of Smad7 gene introduction on the culturedhuman SCFs were also studied.Results: Marked Smad7 protein expression was detected in thevector-treated conjunctival epithelium and fibroblasts that coincidedwith green fluorescein protein expression, whereas faint endogenousSmad7 expression was observed in the control tissue. In vivo Smad7 geneintroduction blocked Smad2/3 nuclear translocation with suppression ofα-smooth muscle actin (αSMA) and vascular endothelial growthfactor (VEGF) in fibroblasts and invasion of macrophages. Smad7 genetransfer suppressed mRNA expressions of connective tissue growth factor(CTGF), VEGF, and monocyte chemoattractant protein-1 in vivo and thoseof type-I collagen, αSMA, and CTGF in vitro.Conclusions: Smad7 gene transfer modulates injury-induced woundhealing of conjunctival tissue in mice, suggesting that this strategymay be effective in preventing excessive scarring following filtrationsurgery. The mechanism might include suppression of activation offibroblasts and reduction of macrophage invasion.

[学科分类] 生物化学/生物物理