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Introduction Insulin resistance is a common hepatic dysfunction amongst individuals suffering from diabetes or obesity and affects 10‐25% of the general population1. The intracellular signaling pathway is reliant on every step being executed correctly. It is evident that excess dietary fats and sugars will result in obesity and likely diabetes. This cellular machinery can be altered when there is a build‐up of lipids which impact molecular insulin signaling. Our objective is to determine if chronic intake of fructose by male liver androgen receptor knockout (Liv‐ARKO) mice will show cascade alteration resulting in increased resistance to insulin when compared to male Liv‐ARKO mice on a control diet. We hypothesized that LivARKO mice on HFrD would show impaired insulin action when compared to control and chow diet mice. Methods We placed male Liv‐ARKO mice on high fructose (HFrD), Control (Research Diets Inc), and Chow diets. We performed insulin tolerance tests (ITT), glucose tolerance tests (GTT), and pyruvate tolerance tests (PTT) after 1‐2 months of being on diets. The mice were later sacrificed, and their tissues were extracted for further tests. To assess differences in insulin action that may arise from increased fructose some mice were given a dose of 0.5 U/kg insulin before being sacrificed to further investigate insulin signaling proteins. BCA protein assays were done to ensure that protein concentration in each sample was standardized. Western blots were performed using tissue from liver to measure molecular insulin action, via p‐AKT presence. Results Male mice on control diet for 2‐months showed improved glucose tolerance and enhanced pyruvate tolerance when compared to male mice on control diet for 1 month. Mice on 2‐month control diet showed impaired insulin sensitivity compared to mice on the same diet for 1 month. Male LivARKO mice displayed no insulin stimulated p‐AKT when on a chow diet. Levels of p‐AKT were the same in basal and insulin male LivARKO mice fed a chow diet. Male LivARKO mice fed a control diet displayed a 4‐fold increase in levels of p‐AKT when stimulated by insulin compared to mice not given insulin (basal). Moreover, male LivARKO mice fed a HFrD displayed no insulin stimulated p‐AKT. Foxo1 levels were not altered by insulin stimulation in male LivARKO mice fed a chow, control, or HFrD. However, it should be noted that control and HFrD both increased Foxo1 levels compared to chow diet. Conclusion Our results suggest that hepatic insulin action or the ability for insulin to initiate glucose uptake in liver is decreased in male LivARKO mice on HFrD. Further investigation of Research Diets Inc. data is necessary to determine why the control diet and HFrD lead to the results discovered.

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. The liver plays an essential component in the metabolism of insulin and androgen signaling. Hyperandrogenism in females can also increase predisposition to insulin resistance. In our study, we placed female liver androgen receptor knock‐out mice (Liv‐ARKO) on high fructose diets (HFrD) to determine if Liv‐ARKO mice demonstrated blunted insulin resistance on HFrD compared to control diet. In this study, female Liv‐ARKO mice were placed on three distinct diets: Control (Research Diets Inc) (CD), chow, and High Fructose (HFrD). The mice were sacrificed after 1 or 2 months. Some 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 tissue from the liver, skeletal muscle, white adipose tissue, ovary, and pituitary glands. BCA assays were used to standardize the protein concentration in each sample. Insulin action can be measured molecularly by examining p‐AKT. If p‐AKT levels increase in the presence of insulin, this indicates that insulin is likely functioning properly in the sample. As seen in previous https://pubmed.ncbi.nlm.nih.gov/34547140/, insulin increased p‐AKT in livers of Liv‐ARKO mice on a chow diet. In contrast, insulin did not increase p‐AKT in livers of Liv‐ARKO mice on the CD for 2 months in comparison to those not given insulin (basal). Furthermore, Liv‐ARKO mice on a HFrD for 2 months displayed an even further decrease in p‐AKT in the liver compared to Liv‐ARKO mice on a CD stimulated with insulin. Liv‐ARKO mice on the CD for 2 months showed enhanced glucose tolerance (EGT) compared to those on the CD for only 1 month. The CD increased glucose tolerance at the whole body level (GTT) and the molecular level (pAKT). Glucose tolerance also increased at 2 months in comparison to 1 month in Liv‐ARKO mice on the CD. This effect is the same and equally as significant for male and female Liv‐ARKO mice. After 2 months on the CD, Liv‐ARKO mice showed impaired insulin sensitivity (IIS) compared to 1 month on the diet. This IIS is significantly greater in female Liv‐ARKO mice compared to male. It was hypothesized that HFrD‐fed Liv‐ARKO would impair insulin action compared to the CD and chow fed mice. The Liv‐ARKO mouse model did not rescue HFrD insulin resistance. The results confirmed this hypothesis and further determined that the CD increased insulin action in comparison to the chow diet. The data suggests that the CD is reducing insulin action in the Liv‐ARKO mice. There is insulin action in Liv‐ARKO mice on the CD as pAKT is present, although at lower levels than in the basal mice. However, compared to the control, the HFrD prohibits the ability of insulin to increase pAKT, indicating complications in the early stages of the insulin signaling pathway. Further research is required into what components of the CD are prompting thi...

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. The liver plays an essential component in the metabolism of insulin and androgen signaling. Hyperandrogenism in females can also increase predisposition to insulin resistance. In our study, we placed female and male liver androgen receptor knock‐out mice (Liv‐ARKO) on high fructose diets (HFrD) and high fat diets (HFD) to determine if Liv‐ARKO mice demonstrated altered glucose‐stimulated insulin secretion on special diets compared to a control diet. In this study, female and male Liv‐ARKO mice were placed on three distinct diets: Control (Research Diets Inc), High Fat (HFD), and High Fructose (HFrD). After one month and two months on these diets, Glucose‐Stimulated Insulin Secretion tests were performed: each group was injected with a 20% glucose solution at 2g of glucose/kg body mass and blood samples were taken via tail milking at 0 minutes, 15 minutes, and 30 minutes. Blood samples were immediately centrifuged and serum supernatant was extracted for further analysis via Sigma Insulin Assay. In the current study, after two months, female mice on HFrD demonstrated lower basal insulin levels compared to female mice fed a control diet. Interestingly, mice on a HFD showed insulin levels that were lower than the basal levels of both control mice and HFrD mice. Furthermore, compared to the control mice, the HFD mice demonstrated lower insulin levels at both basal level and 30 minutes post‐glucose administration. It was hypothesized that HFD and HFrD‐fed Liv‐ARKO mice would impair glucose‐stimulated insulin secretion, which our current study supports. These data suggest that diets high in fructose and fat both blunt insulin secretion following a meal, and to a greater extent in high fat diets. This dysfunction may ultimately play a role in the development of insulin resistance. More research is necessary in order to further investigate the effects of high fat and high fructose diets on glucose‐stimulated insulin secretion and consequent development of insulin resistance.

Insulin resistance is an important component of type 2 diabetes and metabolic syndrome. The liver plays an essential component in the metabolism of insulin and androgen signaling. Sex differences exist in type 2 diabetes with men having a higher prevelance than women. In our study we placed male liver androgen receptor knock‐out mice (Liv‐ARKO) on chow diets to determine if Liv‐ARKO had an effect on insulin resistance on younger age (5 month) compared to older age (10 month). In this study, male Liv‐ARKO mice were kept on chow diets for either 5 months or 10 months and then sacrificed. Some mice were given a dose of 0.5 U/kg insulin before sacrificing to investigate the effects of age on insulin signaling. Western blots were used to determine protein expression in tissue from the liver, skeletal muscle, white adipose tissue. BCA assays were used to standardize the protein concentration in each sample. Upon activation of the insulin signaling pathway, the insulin receptor substrate (IRS) proteins, initiates activation of the phosphatidylinositol 3‐kinase (PI3k) pathways, resulting in stimulation of protein kinases such as Akt. As seen in a previous study1 approximately 5 month old (22 week old) hepatic‐AR‐knockout chow mice showed that when stimulated with insulin there was an increase in PI3k activity. This study did not take it a step further to show what was going on with p‐AKT. It was hypothesized that p‐AKT is lowered in both 5 and 10 month old mice compared to mice not given insulin. Additionally, after 10 months, total AKT was increased. Insulin stimulated p‐Foxo was lowered at 5 months but at 10 months p‐Foxo was increased. Our results suggest that Liver Androgen Receptor is causing decreased insulin action at the level of p‐AKT in both young (5 month) and old (10 month) mice. If insulin is not stimulating p‐AKT, the body may try to make more total AKT to try to compensate; hence the increase in total AKT seen in the 10 month mice. Further investigation should also be performed on the gender differences in these results.