Liver Androgen Receptor Knockout (LivARKO) Male Mice on 3-months of High Fat Diet (HFD) Did Not Experience Insulin Resistance at the Level of p-AKT in White Adipose Tissue

Abstract

Introduction: Insulin resistance affects up to a third of the US adult population and polycystic ovary syndrome (PCOS) affects up to 10% of reproductive-age adult women. Andrisse et al 2021 (PMCID: PMC9097557) showed that deleting the liver androgen receptor (LivARKO) prevented female mice from developing hyperandrogenemia (HA)-induced insulin resistance. Here, we asked the question, does LivARKO prevent high fat diet (HFD) induced insulin resistance? Hypothesis: It was hypothesized that (unlike HA-LivARKO) HFD LivARKO male mice would display impaired insulin action (lowered insulin-stimulated p-AKT) in white adipose tissue in comparison to the Control diet fed LivARKO male mice, suggesting that AR does not play a significant role in regulating HFD-induced insulin resistance. Methods: Male LivARKO mice were placed on two diets: Control (Con, Research Diets Inc, RDI D12450J, Protein (20%), Carbs (70%, corn starch-50%, sucrose-maldextrin-20%, fructose-0%), Fat 10% (lard)) and High Fat (HFD, RDI D12492, Protein (20%), Carbs (20%, corn starch-0%, sucrose-maldextrin-20%, fructose-0%), Fat 60% (lard)). The mice were sacrificed after 3 months on the diet. Half of the mice were given a dose of 0.5 U/kg insulin before sacrificing to investigate the effects of the diets on insulin signaling. Western blots were used to determine protein expression in white adipose tissue (WAT). BCA assays were used to standardize the protein concentration in each sample. Insulin action can be measured molecularly by examining p-AKT Serine 473 (positive regulator, Santa Cruz sc-514032). If p-AKT S473 levels increase in the presence of insulin, this indicates that insulin is likely functioning properly in the sample. Results: Male LivARKO fed a control diet (LivARKO-Con) and administered with 0.5 U/kg insulin displayed significantly lowered p-AKT protein levels compared to male LivARKO-Con that did not get administered an i.p. injection of insulin (Basal), suggesting that male LivARKO-Con mice were experiencing insulin resistance. Additionally, male LivARKO fed a high fructose diet (LivARKO-HFrD) and administered with 0.5 U/kg insulin displayed slightly increased p-AKT protein levels compared to male LivARKO-HFrD-Basal mice. Conclusion: In conclusion, LivARKO male mice on 3-months of HFD were not experiencing insulin resistance at the level of p-AKT in WAT. We are not certain why insulin negatively regulated (or lowered) p-AKT in WAT of LivARKO-Con male mice. This could be an aspect of needing a higher n-value. Further studies in different energy storage tissues and higher n-values are warranted. We would like to thank the NSF for award # 1931045 and the NIH for award # 1R01DK126892-01A1 for supporting this work. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.