Purchase this article with an account.
S.M. Koh; Switching Necrotic to Apoptotic Death Pathway in H2O2-Injured Corneal Endothelial Cells by Vasoactive Intestinal Peptide . Invest. Ophthalmol. Vis. Sci. 2003;44(13):4733.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: Cell death by necrosis, but not apoptosis, leads to inflammation, whose presence in the anterior chamber threatens visual clarity. The study shows that apoptosis is promoted among dying corneal endothelial (CE) cells by VIP (M.W.=3,326), a CE cell autocrine and immunosuppressant present in the aqueous humor. Methods: Corneoscleral explants were dissected from fresh bovine eyes, preconditioned in MEM/HEPES (60 min) and the cornea cups were conditioned in the same plus VIP (0, 10-12-10-6 M, 15 min, 37oC). In addition, VIP-treated-CE-cell-conditioned medium was either concentrated by centrifugal filtration (M.W. cut off=5,000) or fractionated by gel permeation chromatography and used to incubate a second set of explants (75 min). All explants were treated with 1.4 mM H2O2 (17 h, 37oC). CE cell viability and genomic DNA fragmentation were examined using a LIVE/DEAD cell viability kit and agarose gel electrophoresis, respectively. Results: VIP concentration-dependently increased the number of CE cells that survived the subsequent H2O2 treatment but increased the level of genomic DNA fragmentation (revealed as DNA ladders in the agarose gels and a hallmark of apoptosis) in the surviving CE cells. VIP-treated CE cells released a factor into the conditioned medium that demonstrated the apoptosis-promoting activity with an approximate M. W. of 14,000. The maximal releasing activity of VIP was observed at concentrations as low as 10-12 M. The VIP antagonist abolished the apoptosis-promoting effect of VIP but not of that contained in the VIP-treated-CE cell-conditioned medium. Conclusions: While attenuating the acute killing effect of H2O2, VIP delayed CE cell death by promoting the apoptotic pathway at the expense of necrosis. The effect of VIP is due, at lease in part, to a VIP-released factor from the CE cells. Thus, VIP may decrease the inflammatory potential of injured corneal endothelium.
This PDF is available to Subscribers Only