8421 The Effect of Dietary Glycotoxins on Insulin Resistance in Polycystic Ovary Syndrome
Authors: Weidner Adelaide , Vann Kenji , Zhang Joy , Roy Anna , Astapova Olga 
Published: October 2024

Abstract
Disclosure: A. Weidner: None. K. Vann: None. J. Zhang: None. A. Roy: None. O. Astapova: None.
Polycystic ovary syndrome (PCOS) is a chronic systemic disorder that affects both metabolism and reproduction. PCOS is characterized by hyperandrogenism and insulin resistance, which are closely intertwined in this disease pathophysiology. PCOS affects an estimated 10% of people with ovaries and increases risk of endometrial cancer, type 2 diabetes, and major cardiovascular events. Furthermore, treatment options are generally poorly tolerated. Despite its prevalence, severity, and enormous public health burden, the etiology of PCOS is not well-understood. Insulin resistance likely plays a central role in PCOS pathogenesis, and often leads to hyperinsulinemia as the pancreas attempts to compensate for insulin’s decreased efficacy in the body. Moreover, the Western diet is becoming increasingly rich in advanced glycation end products (AGEs): non-enzymatically modified biomolecules that have recently been found to have a harmful effect on insulin sensitivity and are associated with diabetes, aging, and oxidative stress. Serum AGE levels have been reported to be higher in both lean and obese PCOS patients, regardless of PCOS subtype. We have also found higher levels of AGE precursors in the serum of our chronic dihydrotestosterone-induced mouse model of PCOS. Using this mouse model, we have shown that ovarian granulosa cells (GCs) remain insulin-sensitive despite systemic insulin resistance and hyperinsulinemia, manifested by impaired glucose tolerance and increased HOMA-IR. To assess whether GCs respond to insulin through alternative receptor pathways, we knocked down insulin receptor in human granulosa-derived KGN cells and found that insulin-stimulated AKT phosphorylation was only minimally reduced, suggesting that insulin may signal in large part through the insulin-like growth factor 1 receptor (IGF1R) in these cells. Therefore, we believe that compensatory hyperinsulinemia plays a key role in chronic GC hyperstimulation, possibly by rerouting the insulin signal through IGF1R to overcome the resistance to insulin receptor activation, suggesting a mechanism for AGE toxicity in PCOS. We hypothesize that in PCOS, this results in impaired GC function and exacerbation of ovarian dysfunction. We will use our PCOS mouse model to study the effects of a reduced-AGE diet in ameliorating the reproductive and metabolic phenotype of an androgenized PCOS mouse. In preliminary experiments, we have found that a low-AGE diet results in lower fasting glucose in C57BL/6J mice after only 4 weeks. We expect that reproductive symptoms, such as estrous cyclicity, and metabolic symptoms, such as GTT and circulating insulin, will improve in our PCOS mouse model when mice are fed a low-AGE diet throughout development and adulthood. This project has significant clinical implications, as reducing dietary AGEs could provide an effective, tolerable, non-drug therapy option for patients with PCOS.
Presentation: 6/3/2024