Figure 2

Expression of miR-146a and miR-146b is enhanced upon bacterial infections. (A) MiR-146a/b induction in zebrafish embryos by S. typhimurium. Embryos were injected with S. typhimurium SL1027 (inf) or PBS (mock) at 28 hpf and expression of miR-146a/b was analyzed at 8 hpi. The specificity of miRNA inductions was analyzed with morpholinos (MO) targeting miR-146a (146aMO1) or miR-146b (146bMO1). As a control a standard control morpholino (scMO) was injected. Data are the mean ± SEM of samples from two independent experiments. (B) MiR-146a/b induction by the attenuated S. typhimurium LPS mutant (Ra) strain SF1592. Experimental conditions were the same as for infection with wild type S. typhimurium (miR-146a: single experiment, miR-146b: mean ± SEM of three replicates). (C) MiR-146a/b induction in zebrafish larvae with M. marinum infection. Embryos were treated with miR-146a/b-targeting or control morpholinos as above, injected with M. marinum Mma20 (inf) or PBS (mock) at 28 hpf, and expression of miR-146a/b was analyzed in larvae at 6 dpi. Data are the mean ± SEM of samples from two independent experiments. (D) MiR-146a/b induction in M. marinum-infected zebrafish adults. Adult zebrafish were injected intraperitoneally with M. marinum Mma20 or mock-injected with PBS and RNA was collected at 6 dpi[35]. Data are the mean ± SEM of three fish per condition. Expression levels in all experiments were determined by TaqMan qPCR and relative expression levels are shown with the mock control set at 1. Asterisks indicate significant differences (*, P < 0.05; **, P <0.01; ***, P <0.001) tested by one-way ANOVA analysis with Tukey’s method as post-hoc test (A-C) or by an unpaired t-test (D).