Purchase this article with an account.
Valery Shestopalov, Alexey Pronin, Galina Dvoriantchikova, Breanne Prindeville, Junior Tayou, Vladlen Z Slepak; Neurotoxicity of Pannexin1 channel correlates with Panx1 gene expression level in retinal ganglion cells. Invest. Ophthalmol. Vis. Sci. 2014;55(13):1711.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Activation of pannexin1 (Panx1) membrane channels by purinergic P2X receptor agonists and ischemia were shown to facilitate the loss of retinal ganglion cells (RGCs). Previously we showed that RGCs expressed the highest level of Panx1 in the retina. To correlate the activity of Panx1 with cellular resistance to ischemia, we examined the effect of high levels of Panx1 on cell survival under conditions of oxygen-glucose deprivation.
We engineered stable Neuro2A cell line with >100-fold increased levels of Panx1. Cell permeation of Neuro2A lines by ischemia was tested using fluorescent small molecule dyes; cell death was measured using Annexin V/propidium iodide labeling. Permeability to Ca2+ cations was measured using ratiometric time-lapse imaging of fura2. Immunohistochemical and transcriptomic analyses were used to examine expression of Panx1, P2X7 and P2X4 receptors in retinal ganglion cells and in cell lines. In situ detection of Panx1 and P2X7 transcripts was performed using qPCR and RNAscope technology.
RGCs and Neuro2A cells over-expressing Panx1 were significantly more susceptible to ischemia as compared to controls. This high vulnerability correlated well with increased permeability to small molecules and cations. Interestingly, adult RGCs showed differential expression of Panx1, P2X7 and P2X4 receptors during post-embryonic development. In situ detection of Panx1, P2X4 and P2X7 transcripts confirmed elevated expression of Panx1 and P2X4 receptor in RGCs. This data suggest that in the retina Panx1 pairs with P2X4 rather than with P2X7 receptor.
High expression level of Panx1 renders RGCs and other neurons susceptible to ischemic injury. Our results suggest that Panx1-associated mechanisms underlie high vulnerability of these neurons to degenerative diseases induced by ischemia and increased extracellular ATP.
This PDF is available to Subscribers Only