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Involvement Of The Extrinsic And Intrinsic Pathways In Ultraviolet B-Induced Apoptosis Of Corneal Epithelial Cells, John L. Ubels, Courtney D. Glupker, Mark P. Schotanus, Loren D. Haarsma

University Faculty Publications and Creative Works

The goal of this study was to elucidate the pathway by which UVB initiates efflux of K+ and subsequently apoptosis in human corneal limbal epithelial (HCLE) cells. The initial focus of the study was on the extrinsic pathway involving Fas. HCLE cells transfected with Fas siRNA were exposed to 80-150 mJ/cm2 UVB and incubated in culture medium with 5.5 mM K+. Knockdown of Fas resulted in limited reduction in UVB-induced caspase-8 and -3 activity. Patch-clamp recordings showed no difference in UVB-induced normalized K+ currents between Fas transfected and control cells. Knockdown of caspase-8 had no effect on the activation of …