17-Estradiol alleviates high-fat diet-induced inflammatory and metabolic dysfunction in skeletal muscle of male and female mice

17 alpha-estradiol (17 alpha-E2) is a naturally occurring nonfeminizing diastereomer of 17 beta-estradiol that has life span-extending effects in rodent models. To date, studies of the systemic and tissue-specific benefits of 17 alpha-E2 have largely focused on the liver, brain, and white adipose tissue with far less focus on skeletal muscle. Skeletal muscle has an important role in metabolic and age-related disease. Therefore, this study aimed to determine whether 17 alpha-E2 treatment has positive, tissue-specific effects on skeletal muscle during a high-fat feeding. We hypothesized that male, but not female, mice, would benefit from 17 alpha-E2 treatment during a high-fat diet (HFD) with changes in the mitochondrial proteome to support lipid oxidation and subsequent reductions in diacylglycerol (DAG) and ceramide content. To test this hypothesis, we used a multiomics approach to determine changes in lipotoxic lipid intermediates, metabolites, and proteins related to metabolic homeostasis. Unexpectedly, we found that 17 alpha-E2 had marked, but different, beneficial effects within each sex. In male mice, we show that 17 alpha-E2 alleviates HFD-induced metabolic detriments of skeletal muscle by reducing the accumulation of diacylglycerol (DAG), and inflammatory cytokine levels, and altered the abundance of most of the proteins related to lipolysis and beta-oxidation. Similar to male mice, 17 alpha-E2 treatment reduced fat mass while protecting muscle mass in female mice but had little muscle inflammatory cytokine levels. Although female mice were resistant to HFD-induced changes in DAGs, 17 alpha-E2 treatment induced the upregulation of six DAG species. In female mice, 17 alpha-E2 treatment changed the relative abundance of proteins involved in lipolysis, beta-oxidation, as well as structural and contractile proteins but to a smaller extent than male mice. These data demonstrate the metabolic benefits of 17 alpha-E2 in skeletal muscle of male and female mice and contribute to the growing literature of the use of 17 alpha-E2 for multi tissue health span benefits.