Schistosomiasis, one of the most devastating
parasitic diseases, is caused by Schistosoma japonicum (Sj)
infection resulting in serious
liver fibrosis.
Interleukin- (
IL-) 13, which is produced by TH2 cells, is a critical profibrotic
cytokine found in various organs, including the liver.
Tissue transglutaminase (tTG), a group of
multifunctional enzymes, serves a central function in the pathogenesis of chronic
liver diseases. However, the relationship between
IL-13, tTG, and
liver fibrosis during Schistosoma
infection has not been established. This study investigated the involvement of
IL-13 and tTG in liver fibrogenesis during Sj
infection in mice. Five weeks after Sj
infection,
granuloma and
fibrosis development in the liver coincided with an increase in
IL-13 and tTG in the liver and the upregulation of serum
IL-13 in infected mice. Administration of
cystamine, an inhibitor of tTG, abrogated the increase in both tTG and
IL-13 in infected mice and ameliorated liver fibrogenesis and
granuloma development. This result establishes a novel link among
IL-13, tTG, and liver
granuloma and
fibrosis under Sj
infection. Based on their important functions in
liver fibrosis induced by Sj
infection,
IL-13 and tTG could be promising potential
drug targets against
schistosomiasis.