Kidney Week

Abstract: FR-PO617

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

Session Information

• Cystic Kidney Diseases: Mechanisms and Models
  October 25, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Genetic Diseases of the Kidneys

• 1201 Genetic Diseases of the Kidneys: Cystic

Authors

• Ivanov, Veniamin, Henry Ford Health System, Detroit, Michigan, United States

Veniamin Ivanov, MD, PhD

• Arkhipov, Sergey N., Henry Ford Health System, Detroit, Michigan, United States

Sergey N. Arkhipov, PhD

• Pavlov, Tengis S., Henry Ford Health System, Detroit, Michigan, United States

Tengis S. Pavlov, PhD

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 mpkCCD_cl4 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 Pkd1^RC/RC mice was increased compared to the normal mice (Panx1 6.79-fold, p<0.05; P2X7 3.52-fold, p<0.05).

Conclusion

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.

Funding

• NIDDK Support