Blocking connexin 43 hemichannel‐mediated ATP release reduces communication within and between tubular epithelial cells and medullary fibroblasts in a model of diabetic nephropathy

• DOI: 10.1111/dme.14963
• Publication Date: 2022-10-18T15:55:45Z
• Authors: Bethany M. Williams; Chelsy L. Cliff; Isak Demirel; Paul E. Squires; Claire E. Hills
• Keywords: Apyrase; Myofibroblast; Connexon

Fibrosis of renal tubules is the final common pathway in diabetic nephropathy and develops face tubular injury fibroblast activation. Aberrant connexin 43 (Cx43) hemichannel activity has been linked to this damage under euglycaemic conditions, however, its role glycaemic unknown. This study investigated effect a Cx43 blocker (Tonabersat) on cell-cell interactions within between epithelial cells fibroblasts an vitro model nephropathy.Human kidney (HK2) proximal tubule medullary (TK173) were treated low (5 mM) or high (25 glucose ± transforming growth factor beta-1 (TGFβ1) Tonabersat glucose. Carboxyfluorescein dye uptake ATPlite luminescence assessed changes hemichannel-mediated ATP release, while immunoblotting determined protein expression. Co-incubation with ATP-diphosphohydrolase apyrase P2X7R inhibitor (A438079) ATP-P2X7R signalling. Indirect co-culture conditioned media from alternate cell type evaluated paracrine-mediated heterotypic interactions.Tonabersat partially negated glucose/TGFβ1-induced increases release downstream adherens junction extracellular matrix (ECM) expression HK2 TK173 cells. Apyrase A438079 highlighted for driving fibroblasts. studies suggest that secretome Tonabersat-sensitive expression.Tonabersat-sensitive enhances TGFβ1-driven interaction favours myofibroblast The data supports potential benefit inhibition reducing tubulointerstitial fibrosis late-stage nephropathy.