Tropisetron Ameliorated Cyclophosphamide-Induced Hemorrhagic Cystitis via Restraining TLR-4/NF-κB and JAK1/STAT3 Signaling Pathways

Objective: The main pathological changes of hemorrhagic cystitis (HC) are bladder inflammation, bladder epithelial damage and mast cell infiltration. Tropisetron has been corroborate to conduct a protective role in HC, but its specific etiology remains unclear. The objective of this research was to estimate the mechanism of action of Tropisetron in haemorrhagic cystitis tissue.

Methods: Cyclophosphamide (CTX) was utilized to induce the construction of HC rat model, and rats were handled with different doses of Tropisetron. The impact of Tropisetron on the expression of inflammatory factors and oxidative stress factors in the rats with cystitis were measured by western blot, as well as the related proteins of Toll-like Receptor 4/nuclear transcription factor-κB (TLR-4/NF-κB) and januskinase 1/signal transducer and activator of transcription 3 (JAK1/STAT3) pathways.

Results: CTX-induced cystitis in rats was accompanied by notable pathological tissue damage and increased bladder wet weight ratio, elevated mast cell numbers and collagen fibrosis compared to controls. Tropisetron ameliorated CTX-induced injury in a concentration-dependent manner. Futhermore, CTX induced oxidative stress and inflammatory damage, while Tropisetron can alleviate these injuries. Besides, Tropisetron ameliorated CTX-induced cystitis by restraining TLR-4/NF-κB and JAK1/STAT3 signalling pathways.

Conclusions: Taken together, Tropisetron ameliorates cyclophosphamide-induced haemorrhagic cystitis via modulating TLR-4/NF-κB and JAK1/STAT3 signalling pathways. These findings carry important implication for the study of the molecular mechanisms of pharmacological treatment of hemorrhagic cystitis.

JAK1/STAT3; TLR-4/NF-κB; Tropisetron; haemorrhagic cystitis; oxidative stress.