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

Area of Science:

• Reproductive Biology
• Cell Biology
• Pharmacology

Background:

• Triptolide (TP) from Triterygium wilfordii Hook. f. (TWHF) has diverse activities but limited clinical use due to toxicity.
• Sertoli cell cytoskeleton and actin-based adherens junctions (AJ), specifically ectoplasmic specializations (ES), are crucial for spermatogenesis.
• TP's reproductive toxicity is linked to its effects on these cellular structures.

Purpose of the Study:

• To investigate the molecular mechanisms by which Triptolide affects Sertoli cell cytoskeleton and adherens junctions.
• To determine the role of Rho GTPases and their downstream effectors in TP-induced testicular toxicity.

Main Methods:

• Treatment of Sertoli cells with Triptolide.
• Analysis of β-actin and Rho GTPase (RhoA, RhoB, Cdc42, Rac1) expression.
• Assessment of Rho-associated protein kinase (ROCKs) gene expression.
• F-actin immunofluorescence to visualize cytoskeleton integrity.
• Measurement of testin expression as an indicator of ES disassembly.

Main Results:

• Triptolide significantly down-regulated β-actin expression in Sertoli cells.
• TP inhibited the expression of Rho GTPases (RhoA, RhoB, Cdc42, Rac1) and downstream ROCKs.
• F-actin immunofluorescence revealed disruption of the Sertoli cell cytoskeleton network.
• TP treatment increased testin expression, indicating disassembly of ectoplasmic specializations.

Conclusions:

• Triptolide induces cytoskeleton dysfunction in Sertoli cells.
• TP disrupts cell-cell adherens junctions, specifically ectoplasmic specializations.
• Inhibition of Rho GTPases is a key mechanism underlying Triptolide's effects on Sertoli cell structure and function.