Extracellular ATP modulates podocyte function through P2Y purinergic receptors and pleiotropic effects on AMPK and cAMP/PKA signaling pathways

• Published in: Archives of biochemistry and biophysics Vol. 695; p. 108649
• Main Authors: Szrejder, Maria, Rachubik, Patrycja, Rogacka, Dorota, Audzeyenka, Irena, Rychłowski, Michał, Angielski, Stefan, Piwkowska, Agnieszka
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 30-11-2020
• Subjects: Actin cytoskeleton; Adenosine Triphosphate - pharmacokinetics; AMP-activated protein kinase; AMP-Activated Protein Kinases - metabolism; Animals; Cyclic AMP - metabolism; Cyclic AMP-Dependent Protein Kinases - metabolism; Female; P2Y receptors; Podocyte; Podocytes - cytology; Podocytes - metabolism; Protein kinase A; Rats; Rats, Wistar; Receptors, Purinergic P2 - metabolism; rho GTP-Binding Proteins - metabolism; Second Messenger Systems - drug effects; Protein kinase A; VASP; ACC; MLC; DCF; PKA; P2Y receptors; AMP-activated protein kinase; LKB1; PKG; Podocyte; CaMKK-β; ROS; AMPK; Actin cytoskeleton
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1016/j.abb.2020.108649

Podocytes and their foot processes interlinked by slit diaphragms, constitute a continuous outermost layer of the glomerular capillary and seem to be crucial for maintaining the integrity of the glomerular filtration barrier. Purinergic signaling is involved in a wide range of physiological processes in the renal system, including regulating glomerular filtration. We evaluated the role of nucleotide receptors in cultured rat podocytes using non-selective P2 receptor agonists and agonists specific for the P2Y1, P2Y2, and P2Y4 receptors. The results showed that extracellular ATP evokes cAMP-dependent pathways through P2 receptors and influences remodeling of the podocyte cytoskeleton and podocyte permeability to albumin via coupling with RhoA signaling. Our findings highlight the relevance of the P2Y4 receptor in protein kinase A–mediated signal transduction to the actin cytoskeleton. We observed increased cAMP concentration and decreased RhoA activity after treatment with a P2Y4 agonist. Moreover, protein kinase A inhibitors reversed P2Y4-induced changes in RhoA activity and intracellular F-actin staining. P2Y4 stimulation resulted in enhanced AMPK phosphorylation and reduced reactive oxygen species generation. Our findings identify P2Y–PKA–RhoA signaling as the regulatory mechanism of the podocyte contractile apparatus and glomerular filtration. We describe a protection mechanism for the glomerular barrier linked to reduced oxidative stress and reestablished energy balance.
•ATP is involved in regulation of podocyte cytoskeleton and permeability to albumin.•P2Y receptor stimulation evokes cAMP-dependent pathways in podocytes.•P2Y has pleiotropic effects on AMPK and cAMP/PKA signaling pathways in podocytes.•P2Y4 activation in podocytes suppresses the RhoA signaling pathway.