TNIP1 alleviates hepatic ischemia/reperfusion injury via the TLR2-Myd88 pathway

Biochem Biophys Res Commun. 2018 Jun 18;501(1):186-192. doi: 10.1016/j.bbrc.2018.04.209. Epub 2018 May 6.

Abstract

Hepatic ischemia/reperfusion (I/R) injury induces oxidative stress, hepatocyte apoptosis, and release of inflammatory cytokines, which together causes liver damage and even organ dysfunction. TNF-α-induced protein 3-interacting protein 1 (TNIP1) reportedly decreases expression of genes associated with stress response and inflammation. Thus, we investigated the effects of TNIP1 on hepatic cells injury caused by hypoxia/reoxygenation (H/R). Reduced expression of TNIP1 was determined in I/R mice compared to normal mice. Then, TNIP1 transgene mice were used to determine the effects of TNIP1 on mice after treatment for I/R. In the normal transgene (NTG) group, serum liver damage markers alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and gamma glutamyl transferase (GGT) in I/R mice significantly increased compared to the sham-operated mice. However, in the TNIP1 transgene (TNIP1-TG) group, those levels in I/R mice were reduced than that in NTG mice. Additionally, cell viability and apoptosis in the hepatic cell line L02 were detected after H/R treatment, MTT assay showed that cell viability was inhibited after H/R treatment, but reversed after ad-TNIP1 transfection. Cell apoptosis also was inhibited after ad-TNIP1 transfection, as shown by the caspase-3 and caspase-9 levels and Bcl-2 and Bax values. Furthermore, TNIP1 overexpression also attenuated the inflammatory response of L02 cells after H/R treatment. Finally, treatment with TNIP1 reduced the elevated expression of TLR2, TLR4, and Myd88 after H/R injury, but overexpression of TLR4 reversed the effects of TNIP1. In conclusion, TNIP1 may protect H/R-induced hepatic cell injury by inhibiting the TLR4/Myd88 pathway.

Keywords: Hepatic ischemia/reperfusion; Hypoxia/reoxygenation; TLR4/Myd88; TNF-α-induced protein 3-interacting protein 1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Animals
  • Apoptosis
  • Biomarkers / blood
  • Cell Line
  • Cell Proliferation
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Gene Expression
  • Hepatocytes / metabolism
  • Hepatocytes / pathology
  • Humans
  • Liver / injuries*
  • Liver / metabolism*
  • Liver / pathology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Myeloid Differentiation Factor 88 / metabolism
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Reperfusion Injury / metabolism*
  • Reperfusion Injury / pathology
  • Reperfusion Injury / therapy*
  • Signal Transduction
  • Toll-Like Receptor 2 / metabolism
  • Toll-Like Receptor 4 / genetics
  • Toll-Like Receptor 4 / metabolism
  • Transfection

Substances

  • Adaptor Proteins, Signal Transducing
  • Biomarkers
  • DNA-Binding Proteins
  • Myeloid Differentiation Factor 88
  • Recombinant Proteins
  • TNIP1 protein, human
  • Tnip2 protein, mouse
  • Toll-Like Receptor 2
  • Toll-Like Receptor 4