UPEC Colonic-Virulence and Urovirulence Are Blunted by Proanthocyanidins-Rich Cranberry Extract Microbial Metabolites in a Gut Model and a 3D Tissue-Engineered Urothelium.

Uropathogenic Escherichia coli (UPEC) ecology-pathophysiology from the gut reservoir to its urothelium infection site is poorly understood, resulting in equivocal benefits in the use of cranberry as prophylaxis against urinary tract infections. To add further understanding from the previous findings on PAC antiadhesive properties against UPEC, we assessed in this study the effects of proanthocyanidins (PAC) rich cranberry extract microbial metabolites on UTI89 virulence and fitness in contrasting ecological UPEC's environments. For this purpose, we developed an original model combining a colonic fermentation system (SHIME) with a dialysis cassette device enclosing UPEC and a 3D tissue-engineered urothelium. Two healthy fecal donors inoculated the colons. Dialysis cassettes containing 7log10 CFU/mL UTI89 were immersed for 2h in the SHIME colons to assess the effect of untreated (7-day control diet)/treated (14-day PAC-rich extract) metabolomes on UPEC behavior. Engineered urothelium were then infected with dialysates containing UPEC for 6 h. This work demonstrated for the first time that in the control fecal microbiota condition without added PAC, the UPEC virulence genes were activated upstream the infection site, in the gut. However, PAC microbial-derived cranberry metabolites displayed a remarkable propensity to blunt activation of genes encoding toxin, adhesin/invasins in the gut and on the urothelium, in a donor-dependent manner. Variability in subjects' gut microbiota and ensuing contrasting cranberry PAC metabolism affects UPEC virulence and should be taken into consideration when designing cranberry efficacy clinical trials. IMPORTANCE Uropathogenic Escherichia coli (UPEC) are the primary cause of recurrent urinary tract infections (UTI). The poor understanding of UPEC ecology-pathophysiology from its reservoir-the gut, to its infection site-the urothelium, partly explains the inadequate and abusive use of antibiotics to treat UTI, which leads to a dramatic upsurge in antibiotic-resistance cases. In this context, we evaluated the effect of a cranberry proanthocyanidins (PAC)-rich extract on the UPEC survival and virulence in a bipartite model of a gut microbial environment and a 3D urothelium model. We demonstrated that PAC-rich cranberry extract microbial metabolites significantly blunt activation of UPEC virulence genes at an early stage in the gut reservoir. We also showed that altered virulence in the gut affects infectivity on the urothelium in a microbiota-dependent manner. Among the possible mechanisms, we surmise that specific microbial PAC metabolites may attenuate UPEC virulence, thereby explaining the preventative, yet contentious properties of cranberry against UTI.

High dose versus low dose standardized cranberry proanthocyanidin extract for the prevention of recurrent urinary tract infection in healthy women: a double-blind randomized controlled trial.

PURPOSE: Our objective was to assess the efficacy of a high dose cranberry proanthocyanidin extract for the prevention of recurrent urinary tract infection. MATERIAL AND METHODS: We recruited 145 healthy, adult women with a history of recurrent urinary tract infection, defined as ≥ 2 in the past 6 months or ≥ 3 in the past 12 months in this randomized, controlled, double-blind clinical trial. Participants were randomized to receive a high dose of standardized, commercially available cranberry proanthocyanidins (2 × 18.5 mg daily, n = 72) or a control low dose (2 × 1 mg daily, n = 73) for a 24-week period. During follow-up, symptomatic women provided urine samples for detection of pyuria and/or bacteriuria and received an appropriate antibiotic prescription. The primary outcome for the trial was the mean number of new symptomatic urinary tract infections during a 24-week intervention period. Secondary outcomes included symptomatic urinary tract infection with pyuria or bacteriuria. RESULTS: In response to the intervention, a non-significant 24% decrease in the number of symptomatic urinary tract infections was observed between groups (Incidence rate ratio 0.76, 95%CI 0.51-1.11). Post-hoc analyses indicated that among 97 women who experienced less than 5 infections in the year preceding enrolment, the high dose was associated with a significant decrease in the number of symptomatic urinary tract infections reported compared to the low dose (age-adjusted incidence rate ratio 0.57, 95%CI 0.33-0.99). No major side effects were reported. CONCLUSION: High dose twice daily proanthocyanidin extract was not associated with a reduction in the number of symptomatic urinary tract infections when compared to a low dose proanthocyanidin extract. Our post-hoc results reveal that this high dose of proanthocyanidins may have a preventive impact on symptomatic urinary tract infection recurrence in women who experienced less than 5 infections per year. TRIAL REGISTRATION: Clinicaltrials.gov, identifier NCT02572895.

Association of the mammalian proto-oncoprotein Int-6 with the three protein complexes eIF3, COP9 signalosome and 26S proteasome.

The mammalian Int-6 protein has been characterized as a subunit of the eIF3 translation initiation factor and also as a transforming protein when its C-terminal part is deleted. It includes a protein domain, which also exists in various subunits of eIF3, of the 26S proteasome and of the COP9 signalosome (CSN). By performing a two-hybrid screen with Int-6 as bait, we have isolated subunits belonging to all three complexes, namely eIF3-p110, Rpt4, CSN3 and CSN6. The results of transient expression experiments in COS7 cells confirmed the interaction of Int-6 with Rpt4, CSN3 and CSN6, but also showed that Int-6 is able to bind another subunit of the CSN: CSN7a. Immunoprecipitation experiments performed with the endogenous proteins showed that Int-6 binds the entire CSN, but in low amount, and also that Int-6 is associated with the 26S proteasome. Taken together these results show that the Int-6 protein can bind the three complexes with various efficiencies, possibly exerting a regulatory activity in both protein translation and degradation.