CARMA1 mediates TLR-dependent synergistic MUC5AC induction by NTHi and PMA via cross-talk with TRAF6.

<p>(<b>A</b>) CARMA1 knockdown by CARMA1-siRNA efficiently reduced the endogenous CARMA1 expression at both the mRNA and protein level, as assessed by Q-PCR and WB, respectively. (<b>B</b>) CARMA1-siRNA inhibited the synergistic induction of MUC5AC transcription by NTHi and PMA. Values are the means ± S.D. (n = 3). <i>*p<0.05</i> vs. NTHi alone; <i>**p<0.05</i> vs. control siRNA transfeced cells. (<b>C</b>) Synergistic enhancement of NTHi-induced TRAF6 polyubiquitination by PMA was attenuated by CARMA1 knockdown. (<b>D</b>) Schematic representation depicting how CARMA1 mediates the synergistic enhancement of <i>MUC5AC</i> expression in human epithelial cells. The data shown are representative of three independent experiments. CON, control; −, absence of; +, presence of; NTHi, nontypeable <i>Haemophilus influenzae</i>; Ubn, ubiquitin; TLRs, toll-like receptors; TRAF6, TNF receptor associated factor 6; PKC, protein kinase C.