Blockade of Hepatocyte PCSK9 Ameliorates Hepatic Ischemia-Reperfusion Injury by Promoting Pink1-Parkin-Mediated Mitophagy

Cell Mol Gastroenterol Hepatol. 2024;17(1):149-169. doi: 10.1016/j.jcmgh.2023.09.004. Epub 2023 Sep 16.

Abstract

Background & aims: Hepatic ischemia-reperfusion injury is a significant complication of partial hepatic resection and liver transplantation, impacting the prognosis of patients undergoing liver surgery. The protein proprotein convertase subtilisin/kexin type 9 (PCSK9) is primarily synthesized by hepatocytes and has been implicated in myocardial ischemic diseases. However, the role of PCSK9 in hepatic ischemia-reperfusion injury remains unclear. This study aims to investigate the role and mechanism of PCSK9 in hepatic ischemia-reperfusion injury.

Methods: We first examined the expression of PCSK9 in mouse warm ischemia-reperfusion models and AML12 cells subjected to hypoxia/reoxygenation. Subsequently, we explored the impact of PCSK9 on liver ischemia-reperfusion injury by assessing mitochondrial damage and the resulting inflammatory response.

Results: Our findings reveal that PCSK9 is up-regulated in response to ischemia-reperfusion injury and exacerbates hepatic ischemia-reperfusion injury. Blocking PCSK9 can alleviate hepatocyte mitochondrial damage and the consequent inflammatory response mediated by ischemia-reperfusion. Mechanistically, this protective effect is dependent on mitophagy.

Conclusions: Inhibiting PCSK9 in hepatocytes attenuates the inflammatory responses triggered by reactive oxygen species and mitochondrial DNA by promoting PINK1-Parkin-mediated mitophagy. This, in turn, ameliorates hepatic ischemia-reperfusion injury.

Keywords: Hepatic Ischemia-Reperfusion; Mitophagy; PCSK9; PINK1; STING.

MeSH terms

  • Animals
  • Disease Models, Animal
  • Hepatocytes / metabolism
  • Humans
  • Liver Diseases*
  • Mice
  • Mitophagy / genetics
  • Proprotein Convertase 9
  • Protein Kinases / genetics
  • Reperfusion Injury* / metabolism
  • Ubiquitin-Protein Ligases / metabolism

Substances

  • PCSK9 protein, human
  • Proprotein Convertase 9
  • Protein Kinases
  • Ubiquitin-Protein Ligases
  • Pcsk9 protein, mouse
  • PTEN-induced putative kinase
  • parkin protein