Purinergic receptor (P2X7) activation reduces cell–cell adhesion between tubular epithelial cells of the proximal kidney

Publication date: Available online 23 October 2019Source: Nanomedicine: Nanotechnology, Biology and MedicineAuthor(s): Eleftherios Siamantouras, Gareth W. Price, Joe A. Potter, Claire E. Hills, Paul E. SquiresAbstractLoss of epithelial (E)-cadherin mediated cell–cell adhesion impairs gap junction formation and facilitates hemichannel-mediated ATP release in the diabetic kidney. Linked to inflammation and fibrosis, we hypothesized that local increases in inter-cellular ATP activate P2X7 receptors on neighboring epithelial cells of the proximal tubule, to further impair cell–cell adhesion and ultimately exacerbate tubular injury. Immunoblotting confirmed changes in E-cadherin expression in human kidney cells treated with non-hydrolysable ATPγS ± the P2X7 antagonist, A438079. Atomic force microscopy based single-cell force spectroscopy quantified maximum unbinding force, tether rupture events, and work of detachment. Confocal microscopy assessed cytoskeletal reorganization. Our studies confirmed that ATPγS downregulated E-cadherin expression in proximal kidney cells, loss of which was paralleled by a reduction in intercellular ligation forces, decreased tether rupture events and cytoskeletal remodeling. Co-incubation with A438079 restored loss of adhesion, suggesting that elevated extracellular ATP mediates tubular injury through P2X7 induced loss of E-cadherin mediated adhesion.Graphical AbstractIncreases in intercellular ATP activate P2X7 purinergic receptors to cause l...
Source: Nanomedicine: Nanotechnology, Biology and Medicine - Category: Nanotechnology Source Type: research