Abstract: | This study investigated the pharmacological inhibition of the toll‐like receptor 4 (TLR4) genes as a measure to attenuate microcystin‐LR (MC‐LR) reproductive toxicity. Bovine Sertoli cells were pretreated with TLR4‐IN‐C34 (C34) for 1 hour. Thereafter the pretreated and non‐pretreated Sertoli cells were cultured in medium containing 10% heat‐activated fetal bovine serum + 80 μg/L MC‐LR for 24 hours to assess the ability of TLR4‐IN‐C34 to attenuate the toxic effects of MC‐LR. The results showed that TLR4‐IN‐C34 inhibited MC‐LR‐induced mitochondria membrane damage, mitophagy and downregulation of blood‐testis barrier constituent proteins via TLR4/nuclear factor‐kappaB and mitochondria‐mediated apoptosis signaling pathway blockage. The downregulation of the mitochondria electron transport chain, energy production and DNA replication related genes (mt‐ND2, COX‐1, COX‐2, ACAT, mtTFA) and upregulation of inflammatory cytokines (interleukin [IL]‐6, tumor necrosis factor‐α, IL‐1β, interferon‐γ, IL‐4, IL‐10, IL‐13 and transforming growth factor β1) were modulated by TLR4‐IN‐C34. Taken together, we conclude that TLR4‐IN‐C34 inhibits MC‐LR‐related disruption of mitochondria membrane, mitophagy and downregulation of blood‐testis barrier proteins of the bovine Sertoli cell via cytochrome c release and TLR4 signaling blockage. |