The Release of Norepinephrine in C57BL/6J Mice Treated with 6-Hydroxydopamine (6-OHDA) is Associated with Translocations in Enteric Escherichia coli via the QseC Histidine Kinase Receptor

BACKGROUND: We aimed to investigate the effects of norepinephrine (NE) released from endogenous stores on bacterial translocation of Escherichia coli in mice by administration of 6-hydroxydopamine (6-OHDA), which selectively destroys noradrenergic nerve terminals. MATERIAL/METHODS: E. coli strain BW25113 and its derivatives (BW25113ΔqseC and BW25113ΔqseC pQseC) were used in this study. The serum concentrations of endotoxin were analyzed. The strains BW25113, BW25113ΔqseC, and BW25113ΔqseC pQseC were detected respectively in tissue specimens harvested from mice treated with 6-OHDA. RESULTS: Mice treated with BW25113ΔqseC showed reduced levels of bacterial translocation following administration of 6-OHDA compared with mice treated with BW25113. The defect of E. coli QseC receptor caused the norepinephrine-QseC signal chain to be interrupted, and the invasiveness and penetrating power of the bacteria on the intestinal mucosa was weakened, eventually leading to a significant decrease in the incidence of bacterial translocation. CONCLUSIONS: NE modulates the interaction of enteric bacterial pathogens with their hosts via QseC. The blockade of the QseC receptor-mediated effects may be useful to attenuate bacterial translocation.