Diabetes Accelerates Steatohepatitis in Mice: Liver Pathology and Single-Cell Gene Expression Signatures

Am J Pathol. 2024 May;194(5):693-707. doi: 10.1016/j.ajpath.2024.01.007. Epub 2024 Feb 1.

Abstract

Glucose lowering independently reduces liver fibrosis in human nonalcoholic fatty liver disease. This study investigated the impact of diabetes on steatohepatitis and established a novel mouse model for diabetic steatohepatitis. Male C57BL/6J mice were fed a 60% high-fat diet (HFD) and injected with carbon tetrachloride (CCl4) and streptozotocin (STZ) to induce diabetes. The HFD+CCl4+STZ group showed more severe liver steatosis, hepatocyte ballooning, and regenerative nodules compared with other groups. Diabetes up-regulated inflammatory cytokine-associated genes and increased the M1/M2 macrophage ratios in the liver. Single-cell RNA sequencing analysis of nonparenchymal cells in the liver showed that diabetes reduced Kupffer cells and increased bone marrow-derived recruited inflammatory macrophages, such as Ly6Chi-RM. Diabetes globally reduced liver sinusoidal endothelial cells (LSECs). Furthermore, genes related to the receptor for advanced glycation end products (RAGE)/Toll-like receptor 4 (TLR4) were up-regulated in Ly6Chi-RM and LSECs in mice with diabetes, suggesting a possible role of RAGE/TLR4 signaling in the interaction between inflammatory macrophages and LSECs. This study established a novel diabetic steatohepatitis model using a combination of HFD, CCl4, and STZ. Diabetes exacerbated steatosis, hepatocyte ballooning, fibrosis, regenerative nodule formation, and the macrophage M1/M2 ratios triggered by HFD and CCl4. Single-cell RNA sequencing analysis indicated that diabetes activated inflammatory macrophages and impairs LSECs through the RAGE/TLR4 signaling pathway. These findings open avenues for discovering novel therapeutic targets for diabetic steatohepatitis.

MeSH terms

  • Animals
  • Diabetes Mellitus* / metabolism
  • Diabetes Mellitus* / pathology
  • Diet, High-Fat / adverse effects
  • Endothelial Cells / metabolism
  • Humans
  • Liver / metabolism
  • Liver Cirrhosis / pathology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Non-alcoholic Fatty Liver Disease* / pathology
  • Toll-Like Receptor 4 / genetics
  • Toll-Like Receptor 4 / metabolism
  • Transcriptome

Substances

  • Toll-Like Receptor 4