Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin promotes inflammation in mouse testes: The critical role of Klotho in Sertoli cells

Toxicol Lett. 2018 Oct 1:295:134-143. doi: 10.1016/j.toxlet.2018.06.001. Epub 2018 Jun 6.

Abstract

Increasing evidence shows that 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD) enhances inflammation, and inflammation has a significant negative impact on fertility. Therefore, the aim of this study was to investigate the effects of TCDD on testis inflammation. Pregnant mice and primary Sertoli cells were treated with TCDD, and male offspring and Sertoli cells were treated with lipopolysaccharides(LPS). We then measured testis apoptotic cells, proinflammatory cytokines, and observed the Klotho/PDLIM2/p65 pathway. In vivo results revealed that TCDD further enhanced LPS-increased testis apoptotic cells and concentrations of testicular proinflammatory cytokines (IL1β, IL18, and IL12) (p < 0.05). An in vitro investigation showed the levels of proinflammatory cytokines were increased in TCDD + LPS-treated cells compared with LPS-treated cells (p < 0.05). Compared with the LPS-treated cells, expression of Klotho and PDLIM2 was significantly decreased in TCDD + LPS-treated cells (p < 0.05), while expression of p65 and NLRP3 were significantly increased in the cotreatment cells (p < 0.05). However, the addition of Klotho to the TCDD + LPS-cotreated cells significantly increased PDLIM2 and decreased p65 activation and NLRP3 (p < 0.05). Meanwhile, mRNA levels and the secretion of proinflammatory cytokines were both suppressed by exogenous Klotho (p < 0.05). Administration of Klotho decreased TCDD + LPS-induced cytokines and apoptosis in mice (p < 0.05). Taken together, TCDD may increase testicular inflammation by affecting the secretion of proinflammatory cytokines in Sertoli cells via the Klotho/PDLIM2/p65 pathway, which influences the testicular microenvironment and induces germ cell apoptosis.

Keywords: Inflammation; Klotho; Male infertility; TCDD.

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism
  • Animals
  • Apoptosis / drug effects
  • Cells, Cultured
  • Environmental Pollutants / toxicity*
  • Female
  • Fertility / drug effects
  • Glucuronidase / metabolism*
  • Infertility, Male / chemically induced*
  • Infertility, Male / metabolism
  • Infertility, Male / pathology
  • Infertility, Male / physiopathology
  • Inflammation Mediators / metabolism
  • Interleukin-12 / metabolism
  • Interleukin-18 / metabolism
  • Interleukin-1beta / metabolism
  • Klotho Proteins
  • LIM Domain Proteins / metabolism
  • Lipopolysaccharides / pharmacology
  • Male
  • Mice, Inbred C57BL
  • NLR Family, Pyrin Domain-Containing 3 Protein / metabolism
  • Orchitis / chemically induced*
  • Orchitis / metabolism
  • Orchitis / pathology
  • Orchitis / physiopathology
  • Polychlorinated Dibenzodioxins / toxicity*
  • Pregnancy
  • Sertoli Cells / drug effects*
  • Sertoli Cells / metabolism
  • Sertoli Cells / pathology
  • Signal Transduction / drug effects
  • Transcription Factor RelA / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • Environmental Pollutants
  • IL1B protein, mouse
  • Inflammation Mediators
  • Interleukin-18
  • Interleukin-1beta
  • LIM Domain Proteins
  • Lipopolysaccharides
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Nlrp3 protein, mouse
  • Pdlim2 protein, mouse
  • Polychlorinated Dibenzodioxins
  • Rela protein, mouse
  • Transcription Factor RelA
  • Interleukin-12
  • Glucuronidase
  • Klotho Proteins