Phthalate-based polymeric plasticizers are widely used for their durability, transparency, and odorless nature, resulting in human exposure through inhalation, ingestion, or contaminated water. Epidemiological studies have identified bis-phthalate as a potential cardiovascular disease risk factor, though its mechanisms remain unclear. This study investigates the effects of bis-phthalate on endothelial dysfunction (ED), an early event in cardiovascular complications, with a focus on Endoplasmic Reticulum (ER) stress pathways.
View Article and Find Full Text PDFCircular RNA (circRNA) is a neoteric researched transcript that involves gene regulation by serving as a micro-RNA (miRNA) sponge. This circRNA-miRNA-mRNA interaction is being recently explored, and its dysregulation is associated with disease pathogenesis and progression. Studies have demonstrated the involvement of this regulatory network in endothelium dysfunction-mediated regulation of pathology in vascular diseases.
View Article and Find Full Text PDFTGF-β signaling is fundamental for both Th17 and regulatory T (Treg) cell differentiation. However, these cells differ in requirements for downstream signaling components, such as SMAD effectors. To further characterize mechanisms that distinguish TGF-β signaling requirements for Th17 and Treg cell differentiation, we investigated the role of Arkadia (RNF111), an E3 ubiquitin ligase that mediates TGF-β signaling during development.
View Article and Find Full Text PDFT cell expression of sphingosine 1-phosphate (S1P) receptor 1 (S1PR1) enables T cell exit from lymph nodes (LNs) into lymph, while endothelial S1PR1 expression regulates vascular permeability. Drugs targeting S1PR1 treat autoimmune disease by trapping pathogenic T cells within LNs, but they have adverse cardiovascular side effects. In homeostasis, the transporter SPNS2 supplies lymph S1P and enables T cell exit, while the transporter MFSD2B supplies most blood S1P and supports vascular function.
View Article and Find Full Text PDFGut-dwelling Prevotella copri (P. copri), the most prevalent Prevotella species in the human gut, have been associated with diet and disease. However, our understanding of their diversity and function remains rudimentary because studies have been limited to 16S and metagenomic surveys and experiments using a single type strain.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2019
The composition of the gut microbiota is largely determined by environmental factors including the host diet. Dietary components are believed to influence the composition of the gut microbiota by serving as nutrients to a subset of microbes, thereby favoring their expansion. However, we now report that dietary fructose and glucose, which are prevalent in the Western diet, specifically silence a protein that is necessary for gut colonization, but not for utilization of these sugars, by the human gut commensal Silencing by fructose and glucose requires the 5' leader region of the mRNA specifying the protein, designated Roc for regulator of colonization.
View Article and Find Full Text PDFUnlabelled: The mammalian intestine provides nutrients to hundreds of bacterial species. Closely related species often harbor homologous nutrient utilization genes and cocolonize the gut, raising questions regarding the strategies mediating their stable coexistence. Here we reveal that related Bacteroides species that can utilize the mammalian glycan chondroitin sulfate (CS) have diverged in the manner in which they temporally regulate orthologous CS utilization genes.
View Article and Find Full Text PDFCells respond to nutrient availability by expressing nutrient catabolic genes. We report that the regulator controlling utilization of chondroitin sulphate (CS) in the mammalian gut symbiont Bacteroides thetaiotaomicron is activated by an intermediate in CS breakdown rather than CS itself. We determine that the rate-determining enzyme in CS breakdown is responsible for degrading this intermediate and establish that the levels of the enzyme increase 100-fold, whereas those of the regulator remain constant upon exposure to CS.
View Article and Find Full Text PDFCellular processes require specific interactions between cognate protein partners and concomitant discrimination against noncognate partners. Signal transduction by classical two-component regulatory systems typically entails an intermolecular phosphoryl transfer between a sensor kinase (SK) and a cognate response regulator (RR). Interactions between noncognate partners are rare because SK/RR pairs coevolve unique interfaces that dictate phosphotransfer specificity.
View Article and Find Full Text PDFCurr Opin Microbiol
April 2010
Bacterial interaction with eukaryotic hosts is often mediated by classical two-component systems, where a sensor kinase controls the phosphorylated state of a cognate response regulator directly, as well as by atypical two-component systems. In the gut symbiont Bacteroides thetaiotaomicron, the sensor kinase and response regulator domains are fused into a single polypeptide, resulting in a membrane-bound regulator usually directing expression of enzymes that degrade certain sugars, making them digestible for humans. In the opportunistic pathogen Pseudomonas aeruginosa, a sensor kinase alters disease expression programs by binding to and altering the enzymatic properties of a different sensor.
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