Transcriptional Factor Snail Mediates Epithelial-Mesenchymal Transition in Human Bronchial Epithelial Cells Induced by Silica

Epithelial-mesenchymal transition （EMT） plays an important role in fibrotic diseases. We have previously showed that silica induces EMT in human bronchial epithelial cells （BECs）; however, the underlying mechanism of silica-induced EMT is poorly understood. In the present study, we investigated the role of Snail in silica-induced EMT in human BECs in vitro. Human BECs were treated with silica at various concentrations and incubation times. Then MTr assay, western blot, electrophoretic mobility shift assay （EMSA）, and small interfering RNA （siRNA） transfection were performed. We found that silica increased the expression and DNA binding activity of Snail in human BECs. SNAI silica-induced expression siRNA upregulated the siRNA inhibited the of Snail. Moreover, SNAI expression of epithelial marker E-cadherin, but attenuated the expression of mesenchymal marker a-smooth muscle actin and vimentin in silica-stimulated cells. These results suggest that Snail mediates the silica-induced EMT in human BECs.

Drug-eluting intraocular lens with sustained bromfenac release for conquering posterior capsular opacification

Cataract is the leading cause of visual impairment,and posterior capsular opacification(PCO)is the most common long-term complication of modern cataract surgery,which can cause severe visual impairment after surgery.The proliferation,migration,and epithelial-mesenchymal transition(EMT)of residual lens epithelial cells(LECs)stimulated by growth factors and cytokines,are the key pathological mechanisms involved in the development of PCO.This study demonstrated that non-steroidal anti-inflammatory drug(NSAID),bromfenac,was capable of effectively inhibiting cell migration,overexpression of EMT markers,such as fibronectin(FN),matrix metalloproteinase 2(MMP2),α-smooth muscle actin(α-SMA),and transcription factor Snail,and extracellular signal-regulated kinase(ERK)/glycogen synthase kinase-3β(GSK-3β)signaling induced by transforming growth factor-β2(TGF-β2)in vitro.The inhibitory effect of bromfenac on TGF-β2-induced EMT was also verified on a primary lens epithelial cell model using human anterior capsules.Furthermore,based on ultrasonic spray technology,we developed a drug-eluting intraocular lens(IOL)using poly(lactic-co-glycolic acid)(PLGA)with sustained bromfenac release ability for the prevention of PCO development.In the rabbit models of cataract surgery,bromfenac-eluting IOL exhibited remarkable PCO prevention and inflammation suppression effects with excellent biocompatibility.In conclusion,bromfenac can inhibit TGF-β2-induced cell migration and the EMT of LECs via ERK/GSK-3β/Snail signaling.The present study offers a novel approach for preventing PCO through PLGA-based drug sustained-release IOLs.