GRPR down-regulation inhibits spermatogenesis through Ca2+ mediated by PLCβ/IP3R signaling pathway in long-term formaldehyde-exposed rats

Food Chem Toxicol. 2023 Sep:179:113998. doi: 10.1016/j.fct.2023.113998. Epub 2023 Aug 19.

Abstract

Formaldehyde (FA), which is known as an air pollutant, has been proven to induce male infertility. However, the underlying mechanism of FA-induced male infertility remains elusive. In this study, 24 male SD rats were exposed to different levels of FA (0, 0.5, 2.46, and 5 mg/m3) for eight consecutive weeks. Through HE staining and sperm smear, we observed that FA exposure resulted in spermatogenic injury and the sperm quality decreased in rats. The qRT-PCR and Western blot analysis further revealed that GRPR was down-regulated in testicular tissues of FA-exposed rats as well as primary spermatogenic cells. Meanwhile, ZDOCK uncovered an interaction between GRPR and PLCβ. In addition, the CCK8, Fluo 3-AM and Flow cytometry results showed that FA exposure suppressed the expression of GRPR, PLCβ and IP3R, consequently reducing the Ca2+ concentration in spermatogenic cells, inducing apoptosis and inhibiting proliferation of spermatogenic cells. Moreover, rescue experiments confirmed that promoting GRPR could improve intracellular Ca2+ concentration by upregulating PLCβ and IP3R, partially reducing the apoptosis and promoting the proliferation of FA-treated spermatogenic cells. These findings revealed that GRPR participates in spermatogenesis through Ca2+ mediated by the PLCβ/IP3R signaling pathway in FA-exposed rats.

Keywords: Ca(2+); Formaldehyde exposure; GRPR; PLCβ/IP3R; Reproductive toxicology; Spermatogenesis.

MeSH terms

  • Animals
  • Down-Regulation
  • Formaldehyde* / adverse effects
  • Formaldehyde* / toxicity
  • Infertility, Male*
  • Inositol 1,4,5-Trisphosphate Receptors / metabolism
  • Male
  • Phospholipase C beta
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Bombesin / metabolism
  • Semen*
  • Signal Transduction
  • Spermatogenesis*

Substances

  • Formaldehyde
  • Phospholipase C beta
  • Inositol 1,4,5-Trisphosphate Receptors
  • Receptors, Bombesin

Supplementary concepts

  • Formaldehyde poisoning