Caspase-11 promotes NLRP3 inflammasome activation via the cleavage of pannexin1 in acute kidney disease

Acta Pharmacol Sin. 2022 Jan;43(1):86-95. doi: 10.1038/s41401-021-00619-2. Epub 2021 Mar 23.

Abstract

Ischemia/reperfusion (I/R) injury is a major cause of acute kidney injury (AKI) in clinic. The activation of NLRP3 inflammasome is associated with inflammation and renal injury in I/R-induced AKI. In the current study we explored the molecular and cellular mechanisms for NLRP3 inflammasome activation following renal I/R. Mice were subjected to I/R renal injury by clamping bilateral renal pedicles. We showed that I/R injury markedly increased caspase-11 expression and the cleavage of pannexin 1 (panx1) in the kidneys accompanied by NLRP3 inflammasome activation evidenced by the activation of caspase-1 and interlukin-1β (IL-1β) maturation. In Casp-11-/- mice, I/R-induced panx1 cleavage, NLRP3 inflammasome activation as well as renal functional deterioration and tubular morphological changes were significantly attenuated. In cultured primary tubular cells (PTCs) and NRK-52E cells, hypoxia/reoxygenation (H/R) markedly increased caspase-11 expression, NLRP3 inflammasome activation, IL-1β maturation and panx1 cleavage. Knockdown of caspase-11 attenuated all those changes; similar effects were observed in PTCs isolated from Casp-11-/- mice. In NRK-52E cells, overexpression of caspase-11 promoted panx1 cleavage; pretreatment with panx1 inhibitor carbenoxolone or knockdown of panx1 significantly attenuated H/R-induced intracellular ATP reduction, extracellular ATP elevation and NLRP3 inflammasome activation without apparent influence on H/R-induced caspase-11 increase; pretreatment with P2X7 receptor inhibitor AZD9056 also attenuated NLRP3 inflammasome activation. The above results demonstrate that the cleavage of panx1 by upregulated caspase-11 is involved in facilitating ATP release and then NLRP3 inflammasome activation in I/R-induced AKI. This study provides new insight into the molecular mechanism of NLRP3 inflammasome activation in AKI.

Keywords: ATP; AZD9056; NLRP3 inflammasome; NRK-52E cells; P2X7 receptor; acute kidney injury; carbenoxolone; caspase-11; ischemia/reperfusion injury; pannexin 1; primary tubular cells.

MeSH terms

  • Acute Kidney Injury / metabolism*
  • Acute Kidney Injury / pathology
  • Animals
  • Caspases, Initiator / deficiency
  • Caspases, Initiator / metabolism*
  • Cells, Cultured
  • Connexins / metabolism*
  • Dose-Response Relationship, Drug
  • Inflammasomes / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Molecular Structure
  • NLR Family, Pyrin Domain-Containing 3 Protein / metabolism*
  • Nerve Tissue Proteins / metabolism*
  • Reperfusion Injury / metabolism*
  • Reperfusion Injury / pathology
  • Structure-Activity Relationship

Substances

  • Connexins
  • Inflammasomes
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Nerve Tissue Proteins
  • Nlrp3 protein, mouse
  • Panx1 protein, mouse
  • Casp4 protein, mouse
  • Caspases, Initiator