Enhanced ERK-1/2 activation in mice susceptible to coxsackievirus-induced myocarditis
J. Clin. Invest. Mary Anne Opavsky, et al. 109:1561 doi:10.1172/JCI13971 [Go to this article.]

Figure 6
ERK-1/2 activation in the heart is associated with susceptibility to CVB3 myocarditis. (a) ERK-1/2 phosphorylation was increased in the hearts of CVB3-infected mice as early as day 1 postinfection (pi). By day 4, ERK-1/2 activation was more intense in myocarditis-susceptible A/J mice. Levels of phosphorylated ERK-1/2 (P-ERK-1/2) and total ERK-1/2 in the heart were determined by Western blot analysis of tissue homogenates from uninfected controls (0) and days 1, 2, and 4 after CVB3 infection. Results shown are representative of 5 mice per group. (b) The fold change in myocardial P-ERK-1/2:total ERK-1/2 ratios from day 0 (baseline set at 1) was determined following densitometry. By day 2 after infection, ERK-1/2 activation in the myocardium of A/J mice was elevated fivefold above the baseline in uninfected control mice. In A/J mice the intensity of ERK-1/2 phosphorylation continued to increase to eight times baseline by day 4 after infection. ERK-1/2 activation persisted at a lower level in the hearts of myocarditis-resistant C57BL/6 mice. Values are expressed as the mean fold change from baseline (± SEM; n = 5 per group). *P < 0.05 versus day 0 for A/J mice, and on day 4 A/J versus C57BL/6 mice; **P < 0.05 versus day 0 for C57BL/6 mice (ANOVA plus Bonferroni/Dunn post hoc testing).