Inhibition Of IL-13 Induced Collagen Ⅰ By SIL-13Rα2 In NIH-3T3 Fibroblasts And The Profile Of SIL-13Rα2/IL-13 In Mice With Schistosomiasis Japonica

Objective To determine the inhibition of IL-13 by recombinant sIL-13Rα2 in NIH-3T3 fibroblasts for its potential therapeutic effect on hepatic fibrosis of mice with Schistosomiasis japanicum . Method IL-13 and sIL-13Rα2 from liver of BALB/c mice infected with schistosomiasis at different infection time points (weeks 0,6,8,10 and 12) were analyzed with ELISA and RT-PCR.The recombinant sIL-13Rα2 expression plasmid was constructed, followed by transfection of NIH-3T3 fibroblast cells. TypeⅠcollagen produced by NIH-3T3 cells were examined by RT-PCR and Western blotting. Results IL-13 was rising gradually after postinfection, reached to 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 sIL-13Rα2 was similarly going but it reached to peak density after 10 weeks postinfection (4827.426 pg/ml)and then reduced slowly but still higher than norma(l4057.112 pg/ml; P=0.021). The changes of IL-13 and sIL-13Rα2 mRNA coincided with that examined by ELISA. Both IL-13 and sIL-13Rα2 reached to their peak density (P=0.033) at the weeks 8 and 10 (P=0.025),respectively followed by a slow decrease . The sIL-13Rα2 (2mg) could significantly inhibit the effect of IL-13 on NIH-3T3 fibroblast cells, showing a decreased mRNA level(P =0.012)and protein level of the typeⅠcollagen compared with normal groups(P =0.031). Conclusion The sIL-13Rα2 could inhibit the effect of IL-13 on NIH-3T3 fibroblast cells leading to a decrease typeⅠcollagen production, indicating that it might have similar therapeutic effect on the stellate cells in hepatic fibrosis of Schistosomiasis japonica.