Significance of the alteration of STAT3 in the acute phase of Kawasaki disease

Objective:To study IL-6 mediated the signal transducer and activator of transcription 3(STAT3) and phosphorylated STAT3(pSTAT3),STAT3 mRNA expression in acute phase kawasaki disease pathogenesis.Methods:Sixty-four patients with acute kawasaki disease(KD),eighteen patients with infectious disease(ID) and forty-two age-matched normal controls(NC)were studied.The level of STAT3,pSTAT3 protein in whole protein,nucleoprotein of peripheral blood mononuclear cells(PBMCs)before and after IL-6 stimulation were analysed with Western blot.Real-time PCR were performed to evaluate the level of STAT3 mRNA in PBMCs before and after IL-6 stimulation and IL-6R block.Results:Before and after IL-6 stimulation,STAT3,pSTAT3 proteins in whole protein of acute KD PBMCs were higher than NC group.Before IL-6 stimulation,STAT3,pSTAT3 proteins in nucleoprotein of KD were no difference compared with NC group.But after IL-6 stimulation,STAT3,pSTAT3 proteins in nucleoprotein of acute KD were higher than NC group.Before and after IL-6 stimulation,the expression of STAT3 mRNA in acute KD(1.15±0.19,1.74±0.59) were higher than ID group(1.07±0.21,1.45±0.32) and NC group(0.56±0.37,1.03±0.51),coronary arterial injury group(KDCAL+;1.19±0.21,1.81±0.47)were higher than no coronary arterial injury group(KDCAL-;1.13±0.29,1.73±0.48;P0.05).After IL-6R block,STAT3mRNA in KD reduced compare to before and after IL-6 stimulation in KD and ID group(0.99±0.15).Conclusion:There are some factors existed to promote express and activation of STAT3 in acute phase kawasaki disease.In vitro IL-6 not only boost expression and activation of the signal molecular transcription but also promote to nucleus.Blocking experiment point out that IL-6 may play a leading role in excessive expression and activation of STAT3 in KD,which for IL-6R blockers therapy provides experimental evidence in kawasaki disease.