RNA interference targeting transforming growth factor-β typeII receptor suppresses ocular inflammation and fibrosis

[摘要] Purpose: Transforming growth factor-β (TGF-β) is animportant mediator of wound healing responses. In the eye, TGF-βactivity has been implicated in causing corneal haze after laser surgeryand subconjunctival scarring following glaucoma surgery. The purpose ofthe study was to determine whether small interference RNAs (siRNAs)targeting the type II receptor of TGF-β (TβRII) could be usedto suppress the TGF-β action.Methods: TβRII specific siRNAs designed from the human genesequence were transfected into cultured human corneal fibroblasts. Theprotein and transcript levels of the receptor were determined byimmunofluorescence, western blotting, and real time PCR.Immunofluorescence and immunoblotting were carried out to examinefibronectin assembly. A wound closure assay was used to assess cellmigration in in vitro fibroblast cultures. In addition, the in vivoeffects of TβRII siRNA were evaluated in a mouse model of ocularinflammation and fibrosis generated by subconjunctival injection ofphosphate buffered saline and latex beads. Mouse TβRII siRNA wasintroduced into experimental eyes. Cellularity on tissue sections wasevaluated after staining with hematoxylin and eosin. Collagen depositionwas visualized by picrosirius red staining.Results: TβRII siRNAs abrogated the receptor transcript andprotein expression in cultured corneal fibroblasts. The gene knockdowninhibited fibronectin assembly and retarded cell migration. In the mousemodel, introduction of TβRII specific siRNA significantly reducedthe inflammatory response and matrix deposition.Conclusions: TβRII specific siRNAs were efficacious both invitro and in vivo in knocking down the TGF-β action. A directapplication of siRNA into eyes to downregulate TβRII expression mayprovide a novel therapy for preventing ocular inflammation andscarring.

[学科分类] 生物化学/生物物理