Burns Induce Alterations in the Acyl Proteome of Mice and Humans

Abstract

Hypermetabolic reprogramming triggered by thermal injury causes substantial morbidity and mortality. Despite the therapeutic potential of targeting this response, the underlying mechanisms remain poorly understood. Interestingly, protein S-acylation is a reversible post-translational modification induced by metabolic alterations via DHHC acyltransferases. While this modification aids in the regulation of cellular functions, deregulated S-acylation contributes to various diseases by altering protein structure, stability, and localization. However, whether and how S-acylation may impact morbidity and mortality during post-burn hypermetabolism is unknown. In this study, we discovered that alterations in the acyl proteome play a key role in mediating adverse outcomes that occur after burn injury. Using a murine model, we show that burn injury induces profound changes in the expression of various DHHC isoforms in metabolic organs central to regulating post-burn hypermetabolism, the adipose tissue and liver. This was accompanied by increased levels of S-acylated proteins in several pathways involved in mediating the adverse hypermetabolic response, including ER stress, lipolysis, and browning. In fact, similar results were also observed in adipose tissue from severely burned patients, as reflected by increased S-acylation of ERK1/2, eIF2a, ATGL, FGF21, and UCP1 relative to non-burn controls. Importantly, pharmacologically targeting this post-translational modification using a non-selective DHHC inhibitor effectively attenuated burn-induced ER stress, lipolysis, and browning induction in an ex vivo explant model. Together, these findings suggest that S-acylation may facilitate the protein activation profile that drives burn-induced hypermetabolism and that targeting it could potentially be an effective strategy to restore metabolic function and improve outcomes after injury.