40 research outputs found
Early severe inflammatory responses to uropathogenic E. coli predispose to chronic and recurrent urinary tract infection
Chronic infections are an increasing problem due to the aging population and the increase in antibiotic resistant organisms. Therefore, understanding the host-pathogen interactions that result in chronic infection is of great importance. Here, we investigate the molecular basis of chronic bacterial cystitis. We establish that introduction of uropathogenic E. coli (UPEC) into the bladders of C3H mice results in two distinct disease outcomes: resolution of acute infection or development of chronic cystitis lasting months. The incidence of chronic cystitis is both host strain and infectious dose-dependent. Further, development of chronic cystitis is preceded by biomarkers of local and systemic acute inflammation at 24 hours post-infection, including severe pyuria and bladder inflammation with mucosal injury, and a distinct serum cytokine signature consisting of elevated IL-5, IL-6, G-CSF, and the IL-8 analog KC. Mice deficient in TLR4 signaling or lymphocytes lack these innate responses and are resistant, to varying degrees, to developing chronic cystitis. Treatment of C3H mice with the glucocorticoid anti-inflammatory drug dexamethasone prior to UPEC infection also suppresses the development of chronic cystitis. Finally, individuals with a history of chronic cystitis, lasting at least 14 days, are significantly more susceptible to redeveloping severe, chronic cystitis upon bacterial challenge. Thus, we have discovered that the development of chronic cystitis in C3H mice by UPEC is facilitated by severe acute inflammatory responses early in infection, which subsequently are predisposing to recurrent cystitis, an insidious problem in women. Overall, these results have significant implications for our understanding of how early host-pathogen interactions at the mucosal surface determines the fate of disease
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)
In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field
Molecular Regulation of Urothelial Renewal and Host Defenses during Infection with Uropathogenic Escherichia coli
Notes from some crypt watchers: regulation of renewal in the mouse intestinal epithelium
ATG16L1 deficiency in macrophages drives clearance of uropathogenic E. coli in an IL-1β-dependent manner
Urinary tract infections (UTIs) are frequent, commonly recurrent, and costly. Deficiency in a key autophagy protein, ATG16L1, protects mice from infection with the predominant bacterial cause of UTIs, Uropathogenic E. coli (UPEC). Here, we report that loss of ATG16L1 in macrophages accounts for this protective phenotype. Compared with wild-type macrophages, macrophages deficient in ATG16L1 exhibit increased uptake of UPEC and enhanced secretion of interleukin-1β (IL-1β). The increased IL-1β production is dependent upon activation of the NLRP3 inflammasome and caspase-1. IL-1β secretion was also enhanced during UPEC infection of ATG16L1-deficient mice in vivo, and inhibition of IL-1β signaling abrogates the ATG16L1-dependent protection from UTIs. Our results argue that ATG16L1 normally suppresses a host-protective IL-1β response to UPEC by macrophages.Mucosal Immunology advance online publication, 11 February 2015; doi:10.1038/mi.2015.7
Recurrent urinary tract infection and risk of bladder cancer in the Nijmegen bladder cancer study
BACKGROUND: Controversy exists on whether urinary tract infection (UTI) is a risk factor for urinary bladder cancer (UBC). Here, the association is investigated using data from one of the largest bladder cancer case–control studies worldwide. METHODS: Information on (i) history and age at onset of regular cystitis (‘regular low-UTI') and (ii) number and age at onset of UTI treated with antibiotics (‘UTI-ab') from 1809 UBC patients and 4370 controls was analysed. Odds ratios (ORs) and 95% confidence intervals (CI) adjusted for age, education, smoking, and use of aspirin/ibuprofen were generated, for men and women separately. RESULTS: Regular low-UTI was associated with an increased UBC risk (men: OR (95% CI) 6.6 (4.2–11); women: 2.7 (2.0–3.5)), with stronger effects in muscle-invasive UBC. Statistically significant decreased risks (ORs ∼0.65) were observed for up to five UTI-ab, specifically in those who (had) smoked and experienced UTI-ab at a younger age. In women, UTI experienced after menopause was associated with a higher UBC risk, irrespective of the number of episodes. CONCLUSIONS: Regular cystitis is positively associated with UBC risk. In contrast, a limited number of episodes of UTI treated with antibiotics is associated with decreased UBC risk, but not in never-smokers and postmenopausal women
