IPSE, a urogenital parasite-derived immunomodulatory protein, ameliorates ifosfamide-induced hemorrhagic cystitis through downregulation of pro-inflammatory pathways
Ifosfamide and other oxazaphosphorines can result in hemorrhagic cystitis, a constellation of complications caused by acrolein metabolites. We previously showed that a single dose of IPSE, a schistosome-derived host modulatory protein, can ameliorate ifosfamide-related cystitis; however, the exact mechanisms underlying this urotoxic effect and its prevention are not fully understood. To provide insights into IPSEs protective mechanism, we undertook transcriptional profiling of bladders from ifosfamide-treated mice, with or without IPSE pretreatment. Following ifosfamide challenge, there was upregulation of a range of pro-inflammatory genes. The pro-inflammatory pathway involving the IL-1{beta}, TNF and IL-6 triad via NF{kappa}B and STAT3 signaling pathways was identified as the key driver of inflammation. The NRF2-mediated oxidative stress response pathway, which regulates both Hmox1-mediated heme homoeostasis and expression of antioxidant enzymes, was highly activated. Anti-inflammatory and cellular proliferation cascades implicated in tissue repair, namely Wnt, Hedgehog and PPAR pathways, were downregulated. IPSE administration before ifosfamide injection resulted in significant downregulation of major proinflammatory pathways including the triad of IL-1{beta}, TNF and IL-6 pathways, the interferon signaling pathway, and less apparent reduction in oxidative stress responses. Taken together, we have identified signatures of acute phase inflammation and oxidative stress responses in the ifosfamide-injured bladder, which are reversed by pretreatment with IPSE, a parasite derived anti-inflammatory molecule. In addition to providing new insights into the underlying mechanism of IPSEs therapeutic effects, this work has revealed several pathways that could be therapeutically targeted to prevent and treat ifosfamide-induced hemorrhagic cystitis.