Myeloid HDAC7 drives liver inflammation and systemic glucose dysregulation during diet-induced obesity

ObjectivesHistone deacetylase 7 (HDAC7), a member of the classical HDAC family, promotes LPS-inducible glycolysis and inflammatory mediator production in macrophages, innate immune cells that contribute to pathology in metabolic diseases. Here, we investigated myeloid HDAC7 functions in obesity-driven metabolic disease. MethodsWe used gain- and loss-of-function genetic approaches in mice to investigate myeloid HDAC7 functions in hepatic inflammation and metabolic disease, as well as associations with hepatic gene signatures characteristic of advanced chronic liver disease (CLD). ResultsTransgenic expression of Hdac7 in myeloid cells increased liver inflammation and liver mRNA levels of Ccl2 and Il1b, key inflammatory mediators linked to CLD. Liver glycogen levels were also decreased, another feature of CLD. Transgenic expression of Hdac7 in myeloid cells mimicked the hepatic inflammatory phenotype that was observed in mice fed a high fat, high cholesterol, and high sucrose (HFHCHS) diet, an obesity model that mimics some features of metabolic dysfunction-associated steatotic liver disease. In myeloid Hdac7 transgenic mice fed a HFHCHS diet, weight gain was increased, fasted glucose levels were elevated and glucose tolerance was dysregulated by comparison to control mice. Conversely, fasted blood glucose levels were reduced and glucose tolerance was improved in myeloid Hdac7-deleted mice on a HFHCHS diet. HDAC7 mRNA levels were also elevated in the livers of people with advanced CLD and spatial transcriptomics revealed that myeloid HDAC7 directs hepatic gene signatures characteristic of advanced CLD. ConclusionMyeloid HDAC7 contributes to hepatic inflammation and systemic glucose dysregulation in a mouse model of obesity and liver inflammation.