MiRNAs’ impact on human reproduction: their roles as diagnostic biomarkers

Abstract MiRNAs are the most important molecules, involved in almost every process, such as growth, differentiation, and apoptosis, within living cells and from normal development to diseases. Therefore, their unique features, such as noninvasiveness, long-term availability in body fluids, and tissue-specific expression, have made them the preferred biomarkers for infertility. Changes in the levels of certain miRNAs, such as miR-34c-5p and miR-122-5p, in sperm or testicular tissue, as well as polycystic ovary syndrome (PCOS)-related miRNAs, including miR-223, miR-132, miR-93, miR-106b have been associated with inflammation, hyperandrogenism, and ovarian dysfunction. These miRNAs could serve as non-invasive diagnostic tools for the early identification of infertility and improved disease management. These beneficial molecules can promote normal/abnormal pathways by targeting related mRNA with gene expression. This feature can provide strong target-based therapy management. In writing this review, we aimed to collect new evidence of infertility miRNA biomarkers for a better and more precise diagnosis.