Oral Virtual Presentation (Virtual only) ESA-SRB-ANZBMS 2021

The effects of acute in vivo LHCGR stimulation on adult mouse Leydig cells (#242)

Liza O'Donnell 1 2 , Diane Rebourcet 2 , Isabelle Stévant 3 , Pauline Sararols 3 , Ben Lawrence 2 , Serge Nef 3 , Lee B Smith 2
  1. Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton, Victoria, Australia
  2. College of Engineering, Science and Environment, The University of Newcastle, Callaghan, NSW, Australia
  3. Department of Genetic Medicine and Development, Faculty of Medicine, University of Geneva, Geneva, Switzerland

Leydig cells produce androgens to support fertility and other androgen-dependent functions. At puberty, adult Leydig cells (ALCs) produce androgens upon activation of the LHCG receptor (LHCGR) by luteinising hormone (LH). Many Leydig cell genes have been shown to be responsive to LHCGR activation by LH or human chorionic gonadotrophin (hCG). Yet there has been no comprehensive evaluation of the effects of this activation on the mouse ALC transcriptome in vivo. We aimed to identify genes and pathways in ALCs altered by acute in vivo LHCGR stimulation via administration of hCG. Adult (100 days old) transgenic mice expressing GFP-Nr5a11 were injected with vehicle or hCG (5IU/30g body weight). Mice were sacrificed 2 or 6 hours later and testicular ALCs (GFP+++) isolated by FACS to produce a highly purified population1. RNA was sequenced (Illumina HiSeq 2500, 50 bp, paired end, ~35 million reads), bioinformatic analyses performed in R (v3.3.1) and DESeq2 identified differentially expressed genes (DEGs, log2 fold change <-0.5 or >0.5 plus p adj<0.01). After 2hrs of LHCGR stimulation, 1363 transcripts were up-regulated and were significantly associated with cholesterol and steroid metabolism (indicative of stimulation of steroidogenesis) and cell-cell adhesion. In addition, 1524 transcripts were decreased and significantly associated with transcription and DNA damage/repair. Six hours of LHCGR stimulation induced 1297 genes that were highly enriched in functions associated with innate immunity and response to interferon-beta, whereas 1869 down-regulated genes were associated with mitochondria and lipid metabolism. Resident macrophages in the testis can enhance steroidogenesis2, and our results suggest LHCGR activation may drive ALC-immune cell interactions in vivo that support optimal steroidogenesis. We also identified transcripts highly responsive to acute LHCGR stimulation, with unknown functions in Leydig cells, providing opportunities to discover novel regulatory pathways. These data provide new insights into how LHCGR activation supports optimal steroidogenesis and Leydig cell function.

  1. Sararols P, Stevant I, Neirijnck Y, et al. 2021 Front Cell Dev Biol 9: p. 695546
  2. Hedger MP, 2015, Knobil and Neill’s Physiology of Reproduction, 4th Edition, p. 805