Intestinal microbial metabolites are conjectured to affect mucosal integrity through an incompletely characterized mechanism. Here we showed that microbial-specific indoles regulated intestinal barrier function through the xenobiotic sensor, pregnane X receptor (PXR). Indole 3-propionic acid (IPA), in the context of indole, is a ligand for PXR in vivo, and IPA downregulated enterocyte TNF-α while it upregulated junctional protein-coding mRNAs. PXR-deficient (Nr1i2(-/-)) mice showed a distinctly "leaky" gut physiology coupled with upregulation of the Toll-like receptor (TLR) signaling pathway. These defects in the epithelial barrier were corrected in Nr1i2(-/-)Tlr4(-/-) mice. Our results demonstrate that a direct chemical communication between the intestinal symbionts and PXR regulates mucosal integrity through a pathway that involves luminal sensing and signaling by TLR4.
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http://dx.doi.org/10.1016/j.immuni.2014.06.014 | DOI Listing |
Sci Rep
December 2024
Medical Genomics Research Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia.
In order to plan and facilitate the culture of personalized / precision medicine in medical practices within any healthcare institution, it is requisite for healthcare professionals like clinicians to have a clear understanding and approach towards the practices of personalized genetic testing. This nationwide cross-sectional study aimed to measure the perceptions and knowledge of clinicians towards personalized genetic testing and assess their current practices of personalized genetic testing in clinical settings through an online self-administered questionnaire in Saudi Arabia. The results of the study revealed that almost two-fifths of participants were responsible for ordering genetic tests directly (39.
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December 2024
Department of Chemistry and Biochemistry, Centre for Research in Molecular Modeling (CERMM), Concordia University, 7141 Sherbrooke Street West, Montréal, QC, H4B 1R6, Canada.
Nitroglycerin is a potent vasodilator in clinical use since the late 1800s. It functions as a prodrug that is bioactivated by formation of an enzyme-based thionitrate, E-Cys-NO. This intermediate reportedly decomposes to release NO and NO but their relative yields remain controversial.
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December 2024
Key Laboratory of Special Functional and Smart Polymer Materials of Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi, China.
Coordination complexes are promising candidates for powerful electrocatalytic oxygen evolution reaction but challenges remain in favoring the kinetics behaviors through local coordination regulation. Herein, by refining the synergy of carboxylate anions and multiconjugated benzimidazole ligands, we tailor a series of well-defined and stable coordination complexes with three-dimensional supramolecular/coordinated structures. The coordinated water as potential open coordination sites can directly become intermediates, while the metal center easily achieves re-coordination with water molecules in the pores to resist lattice oxygen dissolution.
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December 2024
Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, China.
The potential for mitigating intestinal inflammation through the gut-bone axis in the treatment of osteoporosis is significant. While various gut-derived postbiotics or bacterial metabolites have been created as dietary supplements to prevent or reverse bone loss, their efficacy and safety still need improvement. Herein, a colon-targeted drug delivery system is developed using surface engineering of polyvinyl butyrate nanoparticles by shellac resin to achieve sustained release of postbiotics butyric acid at the colorectal site.
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December 2024
Imperial College Parturition Research Group, Institute of Reproductive and Developmental Biology, Department of Metabolism Digestion and Reproduction, Imperial College London, London, UK.
Lactobacillus species dominance of the vaginal microbiome is a hallmark of vaginal health. Pathogen displacement of vaginal lactobacilli drives innate immune activation and mucosal barrier disruption, increasing the risks of STI acquisition and, in pregnancy, of preterm birth. We describe differential TLR mediated activation of the proinflammatory transcription factor NF-κB by vaginal pathogens and commensals.
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