Alleviation of Hepatic Steatosis by Alpha-Defensin Is Associated with Enhanced Lipolysis

Background and Objectives: The neutrophilic peptide, alpha-defensin, is considered an evolving risk factor intimately linked with lipid mobilization. It was previously linked to augmented liver fibrosis. Here, we assess a potential association between alpha-defensin and fatty liver. Materials and Methods: A cohort of transgenic C57BL/6JDef+/+ male mice that overexpress the human neutrophil-derived alpha-defensin in their polymorphonuclear neutrophils (PMNs) were assessed for liver steatosis and fibrosis development. Wild type (C57BL/6JDef.Wt) and transgenic (C57BL/6JDef+/+) mice were maintained on a standard rodent chow diet for 8.5 months. At the termination of the experiment, systemic metabolic indices and hepatic immunological cell profiling were assessed. Results: The Def+/+ transgenic mice exhibited lower body and liver weights, lower serum fasting glucose and cholesterol, and significantly lower liver fat content. These results were associated with impaired liver lymphocytes count and function (lower CD8, NK cells, and killing marker CD107a). The metabolic cage demonstrated dominant fat utilization with a comparable food intake in the Def+/+ mice. Conclusions: Chronic physiological expression of alpha-defensin induces favorable blood metabolic profile, increased systemic lipolysis, and decreased hepatic fat accumulation. Further studies are needed to characterize the defensin net liver effect.