An ongoing outbreak of multidrug-resistant Salmonella enterica serovar Anatum began in Taiwan in 2015. Pork and poultry were identified as vehicles for transmission. Contaminated meat contributed to the high rate of infections among children.
View Article and Find Full Text PDFChronic inflammation is a common feature of obesity, with elevated cytokines such as interleukin-1 (IL-1) in the circulation and tissues. Here, we report an unconventional IL-1R-MyD88-IRAK2-PHB/OPA1 signaling axis that reprograms mitochondrial metabolism in adipocytes to exacerbate obesity. IL-1 induced recruitment of IRAK2 Myddosome to mitochondria outer membranes via recognition by TOM20, followed by TIMM50-guided translocation of IRAK2 into mitochondria inner membranes, to suppress oxidative phosphorylation and fatty acid oxidation, thereby attenuating energy expenditure.
View Article and Find Full Text PDFBackgrounds & Aims: Alcohol-related liver disease (ALD) is a major cause of chronic liver disease worldwide with limited therapeutic options. Interleukin-1 receptor associated kinase 4 (IRAK4), the master kinase of Toll-like receptor (TLR)/IL-1R-mediated signalling activation, is considered a novel therapeutic target in inflammatory diseases, but has not been investigated in the context of ALD.
Methods: IRAK4 phosphorylation and IRAK1 protein were analysed in liver from alcohol-related hepatitis patients and healthy controls.
Background: The epidemiology of nontyphoidal Salmonella (NTS) resistant to ciprofloxacin or ceftriaxone and its impact on patients' clinical course are rarely reported.
Methods: Children with culture-proven salmonellosis treated in a medical center in northern Taiwan in 2017 were enrolled. To trace the source of Salmonella, Salmonella isolated from food samples were collected from markets.
Monocytes are rapidly recruited to sites of diabetic complications and differentiate into macrophages. Previously, we showed that rat kidney mesangial cells dividing during hyperglycemic stress abnormally synthesize hyaluronan (HA) in intracellular compartments. This initiates a stress response, resulting in an extracellular HA matrix after division that recruits inflammatory cells.
View Article and Find Full Text PDFOpen Forum Infect Dis
December 2019
Background: Nontyphoidal (NTS) is an important foodborne pathogen worldwide. We investigated a 2018 outbreak of highly antimicrobial-resistant serotype Goldcoast in northern Taiwan.
Methods: We collected 30 clinical isolates and 2 meat isolates from this outbreak in New Taipei and Taoyuan, Taiwan in 2018.
Expression of inflammatory genes is determined in part by post-transcriptional regulation of mRNA metabolism but how stimulus- and transcript-dependent nuclear export influence is poorly understood. Here, we report a novel pathway in which LPS/TLR4 engagement promotes nuclear localization of IRAK2 to facilitate nuclear export of a specific subset of inflammation-related mRNAs for translation in murine macrophages. IRAK2 kinase activity is required for LPS-induced RanBP2-mediated IRAK2 sumoylation and subsequent nuclear translocation.
View Article and Find Full Text PDFUnlabelled: Lipopolysaccharide (LPS)-mediated activation of Toll-like receptors (TLRs) in hepatic macrophages and injury to hepatocytes are major contributors to the pathogenesis of alcoholic liver disease. However, the mechanisms by which TLR-dependent inflammatory responses and alcohol-induced hepatocellular damage coordinately lead to alcoholic liver disease are not completely understood. In this study, we found that mice deficient in interleukin-1 receptor-associated kinase M (IRAKM), a proximal TLR pathway molecule typically associated with inhibition of TLR signaling, were actually protected from chronic ethanol-induced liver injury.
View Article and Find Full Text PDFBackground & Aims: Single immunoglobulin and toll-interleukin 1 receptor (SIGIRR), a negative regulator of the Toll-like and interleukin-1 receptor (IL-1R) signaling pathways, controls intestinal inflammation and suppresses colon tumorigenesis in mice. However, the importance of SIGIRR in human colorectal cancer development has not been determined. We investigated the role of SIGIRR in development of human colorectal cancer.
View Article and Find Full Text PDFLow-grade systemic inflammation is often associated with metabolic syndrome, which plays a critical role in the development of the obesity-associated inflammatory diseases, including insulin resistance and atherosclerosis. Here, we investigate how Toll-like receptor-MyD88 signaling in myeloid and endothelial cells coordinately participates in the initiation and progression of high fat diet-induced systemic inflammation and metabolic inflammatory diseases. MyD88 deficiency in myeloid cells inhibits macrophage recruitment to adipose tissue and their switch to an M1-like phenotype.
View Article and Find Full Text PDFEndoplasmic reticulum (ER) stress occurs when unfolded proteins accumulate in the lumen of the organelle, triggering signal transduction events that contribute either to cellular adaptation and recovery or alternatively to cellular dysfunction and death. ER stress has been implicated in numerous diseases. To identify novel modulators of ER stress, we undertook a siRNA library screen of the kinome, revealing Interleukin-1 Receptor-Associated Kinase-2 (IRAK2) as a contributor to unfolded protein response (UPR) signaling and ER stress-induced cell death.
View Article and Find Full Text PDFToll-like receptors transduce their signals through the adaptor molecule MyD88 and members of the IL-1R-associated kinase family (IRAK-1, 2, M and 4). IRAK-1 and IRAK-2, known to form Myddosomes with MyD88-IRAK-4, mediate TLR7-induced TAK1-dependent NFκB activation. IRAK-M was previously known to function as a negative regulator that prevents the dissociation of IRAKs from MyD88, thereby inhibiting downstream signalling.
View Article and Find Full Text PDFInterleukin-1 (IL-1)-induced activation of the mTOR kinase pathway has major influences on Th17 cell survival, proliferation, and effector function. Via biochemical and genetic approaches, the kinases IKKi and GSK3α were identified as the critical intermediate signaling components for IL-1-induced AKT activation, which in turn activated mTOR. Although insulin-induced AKT activation is known to phosphorylate and inactivate GSK3α and GSK3β, we found that GSK3α but not GSK3β formed a constitutive complex to phosphorylate and suppress AKT activation, showing that a reverse action from GSK to AKT can take place.
View Article and Find Full Text PDFInterleukin-1 (IL-1) receptor-associated kinase (IRAK1) is phosphorylated, ubiquitinated, and degraded upon IL-1 stimulation. IRAK1 can be ubiquitinated through both K48- and K63-linked polyubiquitin chains upon IL-1 stimulation. While the Pellino proteins have been shown to meditate K63-linked polyubiquitination on IRAK1, the E3 ligase for K48-linked ubiquitination of IRAK1 has not been identified.
View Article and Find Full Text PDFInterleukin 1 receptor-associated kinase 1(IRAK1), a key molecule in TLR/IL-1R-mediated signaling, is phosphorylated, ubiquitinated, and degraded upon ligand stimulation. We and others have recently identified Pellino proteins as novel RING E3 ubiquitin ligases involved in IRAK1 polyubiquitination and degradation. However, it remains unclear how each Pellino member distinctly regulates TLR/IL-1R signaling by modulating IRAK1 ubiquitination.
View Article and Find Full Text PDFJ Zhejiang Univ Sci B
August 2011
Objective: To study whether Tongxinluo (TXL) can induce angiogenesis in bone marrow mesenchymal stem cells (MSCs), and to investigate the underlying mechanism.
Methods: Bone marrow MSCs were obtained from male Sprague-Dawley rats. We established an angiogenesis model in vitro via matrigel experiment.
Bone marrow-derived plasmacytoid dendritic cells (pDCs) from IL-1R-associated kinase (IRAK)2-deficient mice produced more IFNs than did wild-type pDCs upon stimulation with the TLR9 ligand CpG. Furthermore, in CpG-stimulated IRAK2-deficient pDCs there was increased nuclear translocation of IFN regulatory factor 7, the key transcription factor for IFN gene transcription in these cells. In IRAK2-deficient macrophages, enhanced NF-κB activation and increased expression of CpG-induced genes were detected within 2 h after treatment.
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