Comparing the effect of sitagliptin and metformin on the oocyte and embryo quality in classic PCOS patients undergoing ICSI

The effect of sitagliptin combined with rosiglitazone on autophagy and inflammation in polycystic ovary syndrome by regulating PI3K/AKT/mTOR and TLR4/NF-κB pathway

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder. Sitagliptin (Sit) and rosiglitazone (Ros) are widely used to treat PCOS, but the mechanism is unclear. This study explored the mechanism that Sit and Ros inhibited autophagy and inflammation in PCOS. In this study, 50 female SD rats were divided into 5 groups (n = 10): control, PCOS, Sit, Ros, and Sit+Ros group. The body weight and ovarian weight were measured 2 h after the last administration, and fasting blood glucose, insulin levels were determined. Lipid metabolism and pathological changes were detected by an automatic biochemical analyzer and HE staining. Sex hormone, oxidative stress and inflammatory levels were detected by ELISA. PCR detected IL-18, TNF-α, IL-6, IL-1β, ATG3, and ATG12 mRNA. The PI3K/AKT/mTOR, TLR4/NF-κB pathway and autophagy-related proteins were detected by western blot. Finally, the number of autophagolysosomes was detected by transmission electron microscopy. Sit or Ros alone reduced body weight, ovarian weight, fasting blood glucose, and insulin levels in PCOS rats. It also improved lipid metabolism, sex hormone levels, oxidative stress and pathological changes, restored the estrous cycle, and corpus luteum quantity. In addition, it could reduce the levels of IL-18, TNF-α, IL-6, IL-1β, ATG3, and ATG12 mRNA, inhibit the expression of Beclin1, LC3, PI3K/AKT/mTOR, and TLR4/NF-κB pathway proteins. The Sit+Ros group was more effective than single administration. In conclusion, Sit+Ros inhibited the PI3K/AKT/mTOR, TLR4/NF-κB pathways, thereby inhibiting the autophagy and inflammation of PCOS rats, which will provide a theoretical basis for PCOS.

Effects of Sitagliptin on Metabolic Indices and Hormone Levels in Polycystic Ovary Syndrome: a Meta-analysis of Randomized Controlled Trials

To evaluate the effects of sitagliptin on the metabolic indices and hormone levels in patients with polycystic ovary syndrome (PCOS). PubMed, EMBASE, Web of Science, Cochrane Library, WanFang Data, and China National Knowledge Infrastructure (CNKI) were searched for randomized controlled trials (RCTs) published up to March 2022. Eligible studies were identified based on the inclusion criteria. The primary outcomes included the homeostasis model assessment of insulin resistance (HOMA-IR), body mass index (BMI), and total testosterone level (TT). Other outcomes included levels of sex hormones, glucose, and lipid metabolism. Forty-five studies were initially identified, and 6 RCTs with 394 patients were finally included in this study. The meta-analysis results suggest that sitagliptin improved HOMA-IR (WMD =  - 0.35; 95% CI (- 0.62, - 0.08); P = 0.01), BMI (WMD =  - 1.27; 95% CI (- 1.76, - 0.77); P < 0.00001), TT (SMD =  - 0.66; 95% CI (- 1.25, - 0.07); P = 0.03), and HDL-C (SMD = 0.11; 95% CI (0.03, 0.18); P = 0.005). No significant differences were observed between the sitagliptin and control groups in other outcomes and in terms of adverse events. Evidence from meta-analyses suggests that sitagliptin was superior in improving insulin sensitivity, total serum testosterone, high-density lipoprotein, and body mass index. However, due to the limitations of published studies, it is difficult to draw a definite conclusion. Larger, higher-quality studies are needed to evaluate the efficacy of sitagliptin in women with PCOS.

Female infertility in the era of obesity: The clash of two pandemics or inevitable consequence?

Obesity is an epidemic that has led to a rise in the incidence of many comorbidities: among others, reduced fertility is often under-evaluated in clinical practice. The mechanisms underlying the link between reduced fertility and obesity are numerous, with insulin resistance, hyperglycaemia and the frequent coexistence of polycystic ovary syndrome being the most acknowledged. However, several other factors concur, such as gut microbiome alterations, low-grade chronic inflammation and oxidative stress. Not only do women with obesity take longer to conceive, but in vitro fertilization (IVF) is also less likely to succeed. We herein provide an updated state-of-the-art regarding the molecular bases of what we could define as dysmetabolic infertility, focusing on the clinical aspects, as well as possible treatment.

Knockdown of DPP4 promotes the proliferation and the activation of the CREB/aromatase pathway in ovarian granulosa cells

Dipeptidyl peptidase 4 (DPP4) has been revealed to be upregulated in women suffering from polycystic ovary syndrome (PCOS), which is a common reproductive disorder. The present study was designed to investigate the effects of inhibition of DPP4 expression on the proliferation of ovarian granulosa cells as well as on the activation of the cAMP response element‑binding protein (CREB)/aromatase pathway. The expression levels of DPP4 in rat serum samples with or without PCOS and ovarian granulosa cells (KGN cells) were detected using reverse transcription‑quantitative PCR (RT‑qPCR) and western blot analyses. Cell viability and cell cycle progression were detected using the Cell Counting Kit‑8 assay and flow cytometric analysis, respectively. The 5‑ethynyl‑2'‑deoxyuridine assay was employed to detect the proliferation of glycolaldehyde‑bovine serum albumin (GOA‑BSA)‑treated KGN cells. In addition, RT‑qPCR and western blot analyses were applied to detect the expression levels of CREB, specific cell cycle‑associated proteins and cytochrome P450 (CYP) 19A1 and CYP11A1 enzymes in KGN cells. The expression levels of DPP4 were upregulated in rats with PCOS. Inhibition of DPP4 expression promoted the proliferation and cell cycle arrest of KGN cells. It was also revealed that the expression levels of cell cycle‑associated proteins were upregulated in DPP4‑silenced KGN cells. In addition, their proliferation was decreased following treatment with GOA‑BSA, while the addition of sitagliptin partially reversed these effects. Additionally, sitagliptin reversed the inhibitory effects caused by GOA‑BSA treatment on the cell cycle progression and on the activation of the CREB/aromatase pathway in KGN cells, as determined by the increased expression levels of the cell cycle‑associated proteins as well as those of the CREB protein and the CYP19A1 and CYP11A1 enzymes. In conclusion, inhibition of DPP4 expression promoted the proliferation of KGN cells and the activation of the CREB/aromatase pathway.