Myocardium injury after burn with complicating sepsis about the IL-6 deficiency mice at different age

ZHANG Hong-chao; TAO Wei-ke; SHI Chen; Maass DL; Li-li; DUAN wei; LIU Xin-bing; LIU Chao-zhong

摘要：Background Concerning SIRS injury carries a disproportionately high morbidity and mortality in the elderly to research whether Interleukin-6 be risk or protective inflammatory cytokine as different age mice suffered burn and sepsis.Methods We used TBSA burn and burn adding sepsis(S.pneumoniae)mice model to simulate clinic pathological process.IL-6 knock out is used for evaluating the role of Il-6 in this process,we used wild type C56/BL6 male and IL-6 knock out mice in 2 months and 14 months respectively.In addition to observation of cardiac function,morphology and pathology,we analyzed the IL-6 related cell signal protein: the transcription factor signal transducer and activator of transcription 3(STAT3),the phospho-stat3(p-star3),the sarco(endo)plasmic reticulum Ca2+-ATPase 2a(SERCA2a),the suppressor of cytokine signaling 3(socs3),inducible NO synthase(Inos).As same time,to isolate cardiomyocytes to measure[Ca2+]I(intracellular calcium concentrations).Result Burn complicated by sepsis promoted[Ca2+]I overloading,inflammatory injury and decreased cardiac contractility.Age was a promoter for this procedure.IL-6 deficiency could attenuated this injury process.But the old Il-6 knockout mice didn't get more benefit like the young,although the aged Il-6 knock out mice lead to milder inflammation in heart pathology.Excepting Inos,the variations of STAT3,p-stat3,SERCA2a,socs3 was related to cardiac dysfunction,inflammatory injury,and[Ca2+]overloading.Conclusions The cytokine Il-6 is a risk factor in burn and sepsis pathogenesis.But IL-6 deficiency seem to be disadvantageous for aged mice suffering from burn and sepsis.