Metabolomic-proteomic combination analysis reveals the targets and molecular pathways associated with hydrogen sulfide alleviating NAFLD

Nonalcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease worldwide. Exogenous H2S has been shown to effectively mitigate NAFLD, although little is known about the underlying targets and molecular mechanisms. C57BL/6 mice were fed with normal fat diet (NFD) or high fat diet (HFD) for a total 16 weeks, and HFD-fed mice were treated with saline or NaHS beginning in 12th week. The combination analysis of metabolomics and proteomics of liver tissues was firstly performed to discover the candidate targets and potential molecular pathways involved in H2S mitigating the NAFLD. Compared with NaCl, H2S relieved NAFLD by reducing liver weight, body weight and lipid accumulation in liver, and improving liver pathology and serum biochemical parameters. There were 40 overlapping metabolites in the intersection analysis between comparative analysis of HFD + NaCl vs NFD and HFD + NaHS vs HFD + NaCl based on liver metabolomics. Moreover, a total of 58 proteins were obtained whose changes were reversed after treatment with H2S. A combined analysis of liver metabolomics and proteomics was then conducted, revealing 8 shared molecular pathways, as well as the enrichment of unsaturated fatty acids. In addition, Plin2 may also be a potential target of H2S via the regulation of lipid droplet degradation in alleviating NAFLD. We performed the first study combining metabolomics and proteomics to explore the mechanisms behind the alleviation of NAFLD by H2S. Our results not only provide evidence that H2S alleviates NAFLD but also reveals its possible molecular mechanisms and targets.