Role of Pannexin-1/P2X7 Interaction in Kidney Cyst Development

Document Type

Conference Proceeding

Publication Date

10-1-2024

Publication Title

J Am Soc Nephrol

Abstract

Background: Active extracellular ATP release is conducted by ion channel pannexin-1 (Panx1), expressed in the kidney and previously has been shown to be upregulated in both autosomal dominant and recessive polycystic kidney disease (ADPKD, ARPKD) cystic epithelium and coupled with upregulation of P2X7. Mechanism of regulation of Panx1 channel has not well characterized. We hypothesized that activation of purinergic signaling is a major factor of cystogenesis and regulation of this signaling involves an interaction with P2X7. Methods: We used a model of cystogenesis to test if purinergic signaling affects growth of cysts formed by mpkCCDcl4 cells in Matrigel in a presence of Forskolin with further evaluation of protein and mRNA expression. To test the regulation of purinergic signaling and interaction of Panx1 and P2X7, patch-clamp experiments in transfected or co-transfected CHO cells and co-immunoprecipitation has been performed. Results: Stimulation of P2X receptors of mpkCCDcl4 cysts with α, βMe-ATP, an ATP analog drug, stimulates cyst growth (mean cyst size; vehicle 2903 um2 vs 4343 um2 treated<0.001) and Panx1 protein expression (p<0.05) with no effect on mRNA level. Co-immunoprecipitation experiments in mpkCCDcl4 cells revealed that P2X7 receptors bind panx1. Treatment of CHO-K1 cells, co-transfected with PANX1 and P2X7 cDNA plasmids, with αβ-MeATP significantly and reversibly stimulated the activity of Panx1 channels. mRNA level of expression of Panx1 and P2X7 in kidney of Pkd1RC/RC mice was increased compared to the normal mice (Panx1 6.79-fold, p<0.05; P2X7 3.52-fold, p<0.05). Conclusions: Stimulation of P2X7 receptor promote cystogenesis in vitro with subsequent increase of Panx1 protein expression. Activity of Panx1 channel is increased in a similar manner. Giving previously investigated data on Panx1 and P2X7 expression in cystic models, we assume that this mechanism contributes to the ATP release into the cystic space and act as a major factor in cystogenesis.

Volume

35

First Page

648

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