Deoxynivalenol Induces Blood–Testis Barrier Dysfunction through Disrupting p38 Signaling Pathway-Mediated Tight Junction Protein Expression and Distribution in Mice

Abstract

Deoxynivalenol (DON) is widely present in cereals and processed grains. It can disrupt the blood-testicular barrier (BTB), leading to sterility in males; however, the mechanism is unknown. In this study, 30 Kunming mice and TM4 cells were exposed to 0 or 4.8 mg/kg (28 d) and 0–2.4 μM (24 h) of DON, respectively. Histopathological findings showed that DON increased BTB permeability in mice, leading to tight junction (TJ) structural damage. Immunofluorescence results indicated that DON disrupted the localization of zonula occludens (ZO)-1. The results of protein and mRNA expression showed that the expression of ZO-1, occludin, and claudin-11 was reduced, and that the p38/GSK-3β/snail and p38/ATF-2/MLCK signaling pathways were activated in mouse testes and TM4 cells. Pretreatment with the p38 inhibitor SB203580 maintained TJ integrity in TM4 cells after exposure to DON. Thus, DON induced BTB dysfunction in mice by disrupting p38 pathway-mediated TJ expression and distribution.

Deoxynivalenol Induces Intestinal Epithelial Barrier Damage through RhoA/ROCK Pathway-Mediated Apoptosis and F-Actin-Associated Tight Junction Disruption

“…Western blotting results showed that DON increased the ratio of GTP-RhoA/total RhoA as well as protein expression of ROCK and p53 in mice jejunal tissue, suggesting that DON-induced p53-dependent mitochondrial pathway apoptosis may be associated with activation of the RhoA/ROCK pathway in mice jejunum tissue. Furthermore, the RhoA/ROCK pathway directly phosphorylates MLC-2, leading to cytoskeletal contraction, which regulates the generation of apoptotic vesicles and the localized internalization of TJ proteins . Moreover, the RhoA/ROCK pathway mediates F-actin rearrangements through actin-binding proteins .…”

“…Fluorescent staining of ZO-1 was performed with reference to previous methods. 24 Briefly, ZO-1 staining was performed using a primary antibody and a secondary antibody conjugated form. Mice jejunal tissue primary antibody was used with ZO-1 (1:1000, Servicebio, Wuhan, China).…”

“…Fluorescent staining of ZO-1 was performed with reference to previous methods . Briefly, ZO-1 staining was performed using a primary antibody and a secondary antibody conjugated form.…”

“…Furthermore, the RhoA/ROCK pathway directly phosphorylates MLC-2, leading to cytoskeletal contraction, which regulates the generation of apoptotic vesicles and the localized internalization of TJ proteins. 24 Moreover, the RhoA/ROCK pathway mediates F-actin rearrangements through actin-binding proteins. 36 The most typical of these proteins are the Gactin-binding protein profilin 1 and the actin filament-cleaving protein cofilin.…”