Inhibition of IL-13-induced collagen I by sIL-13Rα2 in NIH-3T3 fibroblast cells and the profile of sIL-13Rα2/IL-13 in mice with schistosomiasis / 中国人兽共患病学报

ABSTRACT

To determine the inhibition of IL-13 by recombinant sIL-13Rα2 in NIH-3T3 fibroblast cells for its potential therapeutic value in hepatic fibrosis caused by Schistosoma japanicum in mice . IL-13 and sIL-13Rα2 from liver of BALB/c mice infected with S.japonicum at different infection time (weeks 0,6,8,10 and 12) were analyzed by ELISA and RT-PCR. The recombinant sIL-13Rα2 expression plasmidwas constructed, followed by transfection into NIH-3T3 fibroblast cells. TypeⅠcollagen produced by NIH-3T3 cells were examined by RT-PCR and Western blotting. It was demonstrated that the expression of IL-13 increased gradually after infection, reached peak density (16.1586 pg/mL)at week 8 and then reduced but was still higher than the level of control mice(3.4146 pg/mL;P =0.017 ). The secretion of sIL-13R α2 reached to its peak 10 weeks after infection(4827.426 pg/mL)and then reduced slowly but still higher than normal(4057.112 pg/mL; P=0.021). Meanwhile, the changes in mRNA level of IL-13 and sIL-13R α2 were coincided with that examined by ELISA. Both IL-13 and sIL-13Rα2 reached their peak density (P=0.033) at week 8 and 10 (P=0.025) respectively, and they were followed by a slower degree of decrease. The sIL-13Rα2 could significantly inhibit the effect of IL-13 on NIH-3T3 fibroblast cells, showing decreased mRNA level(P =0.012)and protein level of typeⅠcollagen compared with normal groups(P =0.031). It is concluded that the sIL-13Rα2 can inhibit the effect of IL-13 on NIH-3T3 fibroblast cells which leads to a reduced production of typeⅠcollagen, demonstrating its potential therapeutic value in hepatic fibrosis of schistosomiasis.