Molecular Signatures of Obesity-Associated Infertility in Polycystic Ovary Syndrome: The Emerging Role of Exosomal microRNAs and Non-Coding RNAs.

Polycystic ovarian syndrome (PCOS) is one of the most common endocrine and metabolic conditions affecting women of reproductive age. This condition affects around 20% of this demographic and is characterized by polycystic ovarian morphology, hyperandrogenism, and chronic anovulation. Obesity, impacting 40-85% of women with PCOS, exacerbates insulin resistance, increases insulin levels, and intensifies low-grade inflammation. This exacerbates the reproductive and metabolic complications associated with the condition. Recent advancements in molecular biology have underscored the significance of non-coding RNAs, including as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), as crucial regulators of gene expression and prospective biomarkers for PCOS. Exosome-derived microRNAs (ex-miRNAs) have emerged as compelling candidates due to their stability in body fluids and their capacity to promote intercellular communication among adipose tissue, the ovary, and the endometrium. Research, encompassing both experimental and clinical studies, has shown that ex-miRNAs display differing expression levels in women with obesity-related PCOS. Several of these ex-miRNAs are associated with networks that govern inflammation, glucose metabolism, steroidogenesis, and folliculogenesis. Moreover, the encapsulation of these chemicals within exosomes safeguards them from enzymatic breakdown, hence augmenting their potential as non-invasive biomarkers for diagnosis, prognosis, and treatment monitoring. Despite the initial results being encouraging, challenges remain in standardising exosome separation, quantifying miRNA, and analyzing functional data within the complex pathophysiology of PCOS. This narrative review consolidates existing evidence regarding the molecular signatures of obesity-related infertility in PCOS, emphasising the growing significance of exosomal miRNAs and other non-coding RNAs, while examining their translational potential for early diagnosis and personalised therapeutic approaches.