Triptolide disrupts the actin-based Sertoli-germ cells adherens junctions by inhibiting Rho GTPases expression

Toxicol Appl Pharmacol. 2016 Nov 1:310:32-40. doi: 10.1016/j.taap.2016.08.017. Epub 2016 Aug 21.

Abstract

Triptolide (TP), derived from the medicinal plant Triterygium wilfordii Hook. f. (TWHF), is a diterpene triepoxide with variety biological and pharmacological activities. However, TP has been restricted in clinical application due to its narrow therapeutic window especially in reproductive system. During spermatogenesis, Sertoli cell cytoskeleton plays an essential role in facilitating germ cell movement and cell-cell actin-based adherens junctions (AJ). At Sertoli cell-spermatid interface, the anchoring device is a kind of AJ, known as ectoplasmic specializations (ES). In this study, we demonstrate that β-actin, an important component of cytoskeleton, has been significantly down-regulated after TP treatment. TP can inhibit the expression of Rho GTPase such as, RhoA, RhoB, Cdc42 and Rac1. Downstream of Rho GTPase, Rho-associated protein kinase (ROCKs) gene expressions were also suppressed by TP. F-actin immunofluorescence proved that TP disrupts Sertoli cells cytoskeleton network. As a result of β-actin down-regulation, TP treatment increased expression of testin, which indicating ES has been disassembled. In summary, this report illustrates that TP induces cytoskeleton dysfunction and disrupts cell-cell adherens junctions via inhibition of Rho GTPases.

Keywords: Adherens Junctions; Ectoplasmic Specializations; Rho GTPases; Triptolide.

MeSH terms

  • Actins / metabolism*
  • Adherens Junctions / drug effects*
  • Adherens Junctions / metabolism
  • Animals
  • Diterpenes / pharmacology*
  • Epoxy Compounds / pharmacology
  • Germ Cells / drug effects*
  • Germ Cells / metabolism
  • Infertility, Male / chemically induced
  • Male
  • Phenanthrenes / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Sertoli Cells / drug effects*
  • Sertoli Cells / metabolism
  • rho GTP-Binding Proteins / antagonists & inhibitors*
  • rho GTP-Binding Proteins / metabolism

Substances

  • Actins
  • Diterpenes
  • Epoxy Compounds
  • Phenanthrenes
  • triptolide
  • rho GTP-Binding Proteins