Krüppel-like factor 6 is a transcriptional activator of autophagy in acute liver injury

Sci Rep. 2017 Aug 14;7(1):8119. doi: 10.1038/s41598-017-08680-w.

Abstract

Krüppel-like factor 6 (KLF6) is a transcription factor and tumor suppressor. We previously identified KLF6 as mediator of hepatocyte glucose and lipid homeostasis. The loss or reduction of KLF6 is linked to the progression of hepatocellular carcinoma, but its contribution to liver regeneration and repair in acute liver injury are lacking so far. Here we explore the role of KLF6 in acute liver injury models in mice, and in patients with acute liver failure (ALF). KLF6 was induced in hepatocytes in ALF, and in both acetaminophen (APAP)- and carbon tetrachloride (CCl4)-treated mice. In mice with hepatocyte-specific Klf6 knockout (DeltaKlf6), cell proliferation following partial hepatectomy (PHx) was increased compared to controls. Interestingly, key autophagic markers and mediators LC3-II, Atg7 and Beclin1 were reduced in DeltaKlf6 mice livers. Using luciferase assay and ChIP, KLF6 was established as a direct transcriptional activator of ATG7 and BECLIN1, but was dependent on the presence of p53. Here we show, that KLF6 expression is induced in ALF and in the regenerating liver, where it activates autophagy by transcriptional induction of ATG7 and BECLIN1 in a p53-dependent manner. These findings couple the activity of an important growth inhibitor in liver to the induction of autophagy in hepatocytes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetaminophen / pharmacology
  • Acute Lung Injury / chemically induced
  • Acute Lung Injury / metabolism*
  • Acute Lung Injury / pathology
  • Animals
  • Autophagy / drug effects
  • Autophagy / physiology*
  • Carbon Tetrachloride / pharmacology
  • Carcinoma, Hepatocellular / metabolism
  • Carcinoma, Hepatocellular / pathology
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cell Proliferation / physiology
  • Gene Expression Regulation / drug effects
  • Gene Expression Regulation / physiology
  • Genes, Tumor Suppressor / drug effects
  • Genes, Tumor Suppressor / physiology
  • Hep G2 Cells
  • Hepatectomy / methods
  • Hepatocytes / drug effects
  • Hepatocytes / metabolism
  • Hepatocytes / physiology
  • Humans
  • Kruppel-Like Factor 6 / metabolism*
  • Liver / drug effects
  • Liver / metabolism
  • Liver / pathology
  • Liver Neoplasms / metabolism
  • Liver Neoplasms / pathology
  • Liver Regeneration / drug effects
  • Liver Regeneration / physiology
  • Mice
  • Mice, Inbred C57BL
  • Transcription, Genetic / drug effects
  • Transcription, Genetic / physiology*
  • Transcriptional Activation / drug effects
  • Transcriptional Activation / physiology*

Substances

  • Kruppel-Like Factor 6
  • Acetaminophen
  • Carbon Tetrachloride