THE ROLE OF LUTEINIZING HORMONE (LH) RECEPTOR IN THE REGULATION OF OOCYTE MATURATION: A SYSTEMATIC LITERATURE REVIEW

The hormone luteinizing hormone (LH) is an important glycoprotein hormone that controls the activity of the gonadal organs, which in turn affects the physiology of the menstrual cycle. For LH to exert its effects, its specific receptor (LHR) must be expressed by cumulus cells. Objective: To determine the role of LH receptors (Luteinizing Hormone) in the regulation of human oocyte maturation processes Method:Systematic Literature Review (SLR). Data collection was conducted by documenting all articles based on predefined inclusion and exclusion criteria. A total of 10 national and international journal articles were retrieved from databases such as Google Scholar, PubMed, and Science Direct, using specific keywords related to the role of LH receptors and oocyte maturation. The literature search and study selection process followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Results:The highest expression of Luteinizing Hormone Receptor (LHR) observed in preovulatory follicles. Cumulus cell maturation, covering 100% of the oocytes, was 74%. FSHR and LHR mRNA expression levels increased with an increase in LH concentration in the in vitro maturation (IVM) medium. After 24 hours of IVM, there was a significant downregulation in the expression of LHR and FSHR.The mRNA and protein levels of FSHR and LHR in the cumulus-oocyte complex gradually decreased with increasing doses of FRBI in the IVM media compared to the control group. Majority of the cumulus cells from MII oocytes had RGS2/B2M gene expression of more than 50%. LH receptor expression in granulosa cells positively correlated with morphology, oocyte maturity, and fertility rate in the poor responder group. Granulosa cells from an agonist-triggered cycle with recombinant human chorionic gonadotropin (rhCG) for 24 hours were observed to increase viability, regulate mRNA expression of 3β-HSD, LH receptor, VEGF, and BCL-L2. More than 50% of the oocytes are matured after hCG injectionat an hCG concentration of 119.8 mIU/mL. Conclusion:LH needs receptor binding and expression for proper function, resulting in improved oocyte maturation with optimal LHR concentration which is 10 µg/mL LH. LHR expression is highest in preovulatory follicles. LHR expression increases during antral follicle growth. Supplementing media with hCG improves oocyte maturity with a 77 mIU/mL cutoff value. Supplementation with FRBI reduce LHR expression in COCs. The number of cumulus cells can also indicate the level of oocyte maturity, where cumulus cells covering 100% of the oocytes show the highest oocyte maturation.