LH receptor gene expression in cumulus cells in women entering an ART program

Luteinizing hormone (LH) exerts its actions through its receptor (LHR), which is mainly expressed in theca cells and to a lesser extent in oocytes, granulosa and cumulus cells. The aim of the present study was the investigation of a possible correlation between LHR gene and LHR splice variants expression in cumulus cells and ovarian response as well as ART outcome.

Forty patients undergoing ICSI treatment for male factor infertility underwent a long luteal GnRH-agonist downregulation protocol with a fixed 5-day rLH pre-treatment prior to rFSH stimulation and samples of cumulus cells were collected on the day of egg collection. RNA extraction and cDNA preparation was followed by LHR gene expression investigation through real-time PCR. Furthermore, cumulus cells were investigated for the detection of LHR splice variants using reverse transcription PCR.

Concerning LHR expression in cumulus cells, a statistically significant negative association was observed with the duration of ovarian stimulation (odds ratio = 0.23, p = 0.012). Interestingly, 6 over 7 women who fell pregnant expressed at least two specific types of LHR splice variants (735 bp, 621 bp), while only 1 out of 19 women that did not express any splice variant achieved a pregnancy.

Consequently, the present study provide a step towards a new role of LHR gene expression profiling as a biomarker in the prediction of ovarian response at least in terms of duration of stimulation and also a tentative role of LHR splice variants expression in the prediction of pregnancy success.