P2X7receptors mediate deleterious renal epithelial-fibroblast cross talk Article (Web of Science)

abstract

  • Peritubular fibroblasts in the kidney are the major erythropoietin-producing cells and also contribute to renal repair following acute kidney injury (AKI). Although few fibroblasts were observed in the interstitium adjacent to damaged tubular epithelium in the early phase of AKI, the underlying mechanism by which their numbers were reduced remains unknown. In this study, we tested the hypothesis that damaged renal epithelial cells directly induce renal interstitial fibroblast death by releasing intracellular ATP and activating purinergic signaling. Exposure of a cultured rat renal interstitial fibroblast cell line (NRK-49F) to necrotic renal proximal tubular cells (RPTC) lysate or supernatant induced NRK-49F cell death by apoptosis and necrosis. Depletion of ATP with apyrase or inhibition of the P2X purinergic receptor with pyridoxal phosphate-6-azophenyl-2′,4′-disulfonic acid blocked the deleterious effect of necrotic RPTC supernatant. The P2X7receptor, an ATP-sensitive purinergic receptor, was not detected in cultured NRK-49F cells but was inducible by necrotic RPTC supernatant. Treatment with A438079, a highly selective P2X7receptor inhibitor, or knockdown of the P2X7receptor with small interference RNA diminished renal fibroblast death induced by necrotic RPTC supernatant. Conversely, overexpression of the P2X7receptor potentiated this response. Collectively, these findings provide strong evidence that damaged renal epithelial cells can directly induce the death of renal interstitial fibroblasts by ATP activation of the P2X7receptor.

authors

  • Ponnusamy, Murugavel
  • Ma, Li
  • Gong, Rujun
  • Pang, Maoyin
  • Chin, Y. Eugene
  • Zhuang, Shougang

publication date

  • 2011

webpage

published in

start page

  • F62

end page

  • F70

volume

  • 300

issue

  • 1