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Bronchial mucosal IFN-α/β and pattern recognition receptor expression in patients with experimental rhinovirus-induced asthma exacerbations.
Zhu, J, Message, SD, Mallia, P, Kebadze, T, Contoli, M, Ward, CK, Barnathan, ES, Mascelli, MA, Kon, OM, Papi, A, et al
The Journal of allergy and clinical immunology. 2019;(1):114-125.e4
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Abstract
BACKGROUND The innate immune system senses viral infection through pattern recognition receptors (PRRs), leading to type I interferon production. The role of type I interferon and PPRs in rhinovirus-induced asthma exacerbations in vivo are uncertain. OBJECTIVES We sought to compare bronchial mucosal type I interferon and PRR expression at baseline and after rhinovirus infection in atopic asthmatic patients and control subjects. METHODS Immunohistochemistry was used to detect expression of IFN-α, IFN-β, and the PRRs: Toll-like receptor 3, melanoma differentiation-associated gene 5, and retinoic acid-inducible protein I in bronchial biopsy specimens from 10 atopic asthmatic patients and 15 nonasthmatic nonatopic control subjects at baseline and on day 4 and 6 weeks after rhinovirus infection. RESULTS We observed IFN-α/β deficiency in the bronchial epithelium at 3 time points in asthmatic patients in vivo. Lower epithelial IFN-α/β expression was related to greater viral load, worse airway symptoms, airway hyperresponsiveness, and reductions in lung function during rhinovirus infection. We found lower frequencies of bronchial subepithelial monocytes/macrophages expressing IFN-α/β in asthmatic patients during infection. Interferon deficiency at baseline was not accompanied by deficient PRR expression in asthmatic patients. Both epithelial and subepithelial PRR expression were induced during rhinovirus infection. Rhinovirus infection-increased numbers of subepithelial interferon/PRR-expressing inflammatory cells were related to greater viral load, airway hyperresponsiveness, and reductions in lung function. CONCLUSIONS Bronchial epithelial IFN-α/β expression and numbers of subepithelial IFN-α/β-expressing monocytes/macrophages during infection were both deficient in asthmatic patients. Lower epithelial IFN-α/β expression was associated with adverse clinical outcomes after rhinovirus infection in vivo. Increases in numbers of subepithelial cells expressing interferon/PRRs during infection were also related to greater viral load/illness severity.
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RNA regulons are essential in intestinal homeostasis.
Parham, LR, Williams, PA, Chatterji, P, Whelan, KA, Hamilton, KE
American journal of physiology. Gastrointestinal and liver physiology. 2019;(1):G197-G204
Abstract
Intestinal epithelial cells are among the most rapidly proliferating cell types in the human body. There are several different subtypes of epithelial cells, each with unique functional roles in responding to the ever-changing environment. The epithelium's ability for rapid and customized responses to environmental changes requires multitiered levels of gene regulation. An emerging paradigm in gastrointestinal epithelial cells is the regulation of functionally related mRNA families, or regulons, via RNA-binding proteins (RBPs). RBPs represent a rapid and efficient mechanism to regulate gene expression and cell function. In this review, we will provide an overview of intestinal epithelial RBPs and how they contribute specifically to intestinal epithelial stem cell dynamics. In addition, we will highlight key gaps in knowledge in the global understanding of RBPs in gastrointestinal physiology as an opportunity for future studies.
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RANK/RANKL/OPG pathway is an important for the epigenetic regulation of obesity.
Kalkan, R, Becer, E
Molecular biology reports. 2019;(5):5425-5432
Abstract
Obesity is a complex disorder that is influenced by genetic and environmental factors. DNA methylation is an epigenetic mechanism that is involved in development of obesity and its metabolic complications. The aim of this study was to investigate the association between the RANKL and c-Fos gene methylation on obesity with body mass index (BMI), lipid parameters, homeostasis model assessment of insulin resistance (HOMA-IR), plasma leptin, adiponectin and resistin levels. The study included 68 obese and 46 non-obese subjects. Anthropometric parameters, including body weight, body mass index, waist circumference, and waist-hip ratio, were assessed. Serum glucose, triglycerides (TG), total cholesterol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), plasma leptin, adiponectin and resistin levels were measured. Methylation status of RANKL and c-Fos gen were evaluated by MS-HRM. Statistically significant differences were observed between obese patients and the controls with respect to RANKL and c-Fos gene methylation status (p < 0.001). Also, statistically significant importance was observed RANKL gene methylation and increased level of leptin in obese subjects (p = 0.0081). At the same time, statistically significant association between methylation of c-Fos and increased level of adiponectin was observed in obese patients (p = 0.03) On the other hand, decreased level of resistin was observed where the c-Fos was unmetyladed in controls (p = 0.01). We conclude that methylation of RANKL and c-Fos genes have significant influences on obesity and adipokine levels. Based on literature this was the first study which shows the interactions between RANKL and c-Fos methylation and obesity.
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The Atherosclerosis Risk Variant rs2107595 Mediates Allele-Specific Transcriptional Regulation of HDAC9 via E2F3 and Rb1.
Prestel, M, Prell-Schicker, C, Webb, T, Malik, R, Lindner, B, Ziesch, N, Rex-Haffner, M, Röh, S, Viturawong, T, Lehm, M, et al
Stroke. 2019;(10):2651-2660
Abstract
Background and Purpose- Genome-wide association studies have identified the HDAC9 (histone deacetylase 9) gene region as a major risk locus for atherosclerotic stroke and coronary artery disease in humans. Previous results suggest a role of altered HDAC9 expression levels as the underlying disease mechanism. rs2107595, the lead single nucleotide polymorphism for stroke and coronary artery disease resides in noncoding DNA and colocalizes with histone modification marks suggestive of enhancer elements. Methods- To determine the mechanisms by which genetic variation at rs2107595 regulates HDAC9 expression and thus vascular risk we employed targeted resequencing, proteome-wide search for allele-specific nuclear binding partners, chromatin immunoprecipitation, genome-editing, reporter assays, circularized chromosome conformation capture, and gain- and loss-of-function experiments in cultured human cell lines and primary immune cells. Results- Targeted resequencing of the HDAC9 locus in patients with atherosclerotic stroke and controls supported candidacy of rs2107595 as the causative single nucleotide polymorphism. A proteomic search for nuclear binding partners revealed preferential binding of the E2F3/TFDP1/Rb1 complex (E2F transcription factor 3/transcription factor Dp-1/Retinoblastoma 1) to the rs2107595 common allele, consistent with the disruption of an E2F3 consensus site by the risk allele. Gain- and loss-of-function studies showed a regulatory effect of E2F/Rb proteins on HDAC9 expression. Compared with the common allele, the rs2107595 risk allele exhibited higher transcriptional capacity in luciferase assays and was associated with higher HDAC9 mRNA levels in primary macrophages and genome-edited Jurkat cells. Circularized chromosome conformation capture revealed a genomic interaction of the rs2107595 region with the HDAC9 promoter, which was stronger for the common allele as was the in vivo interaction with E2F3 and Rb1 determined by chromatin immunoprecipitation. Gain-of-function experiments in isogenic Jurkat cells demonstrated a key role of E2F3 in mediating rs2107595-dependent transcriptional regulation of HDAC9. Conclusions- Collectively, our findings imply allele-specific transcriptional regulation of HDAC9 via E2F3 and Rb1 as a major mechanism mediating vascular risk at rs2107595.
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Phosphorylation and Signal Transduction Pathways in Translational Control.
Proud, CG
Cold Spring Harbor perspectives in biology. 2019;(7)
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Abstract
Protein synthesis, including the translation of specific messenger RNAs (mRNAs), is regulated by extracellular stimuli such as hormones and by the levels of certain nutrients within cells. This control involves several well-understood signaling pathways and protein kinases, which regulate the phosphorylation of proteins that control the translational machinery. These pathways include the mechanistic target of rapamycin complex 1 (mTORC1), its downstream effectors, and the mitogen-activated protein (MAP) kinase (extracellular ligand-regulated kinase [ERK]) signaling pathway. This review describes the regulatory mechanisms that control translation initiation and elongation factors, in particular the effects of phosphorylation on their interactions or activities. It also discusses current knowledge concerning the impact of these control systems on the translation of specific mRNAs or subsets of mRNAs, both in physiological processes and in diseases such as cancer.
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[MicroRNA-1 regulates fibronectin expression in human trabecular meshwork cells under oxidative stress].
Guo, JH, Su, C, Jiang, SY, Wang, F, Feng, X, Wang, JT
[Zhonghua yan ke za zhi] Chinese journal of ophthalmology. 2019;(5):355-360
Abstract
Objective: To investigate the expression of microRNA-1 (miR-1) and its regulatory function on fibronectin (FN) in human trabecular meshwork cells (HTMC) under oxidative stress. Methods: Experimental study. After HTMC were treated with 0, 60, 100, 200, 400 μmol/L hydrogen peroxide (H(2)O(2)) for 6 h, respectively, the cells were placed in culture medium for 24 h. The expression of miR-1 and FN mRNA in these cells were detected by real-time quantitative PCR. According to bioinformatics analysis, the target gene of miR-1 is predicted to be FN; pcDNA3/pri-miR-1 vectors, pcDNA3/enhanced green fluorescent protein (EGFP)-FN-3'UTR vectors and pcDNA3/EGFP-FN-3'UTRmut vectors were constructed. pcDNA3/pri-miR-1 were co-transfected with pcDNA3/EGFP-FN-3'UTR or pcDNA3/EGFP-FN-3'UTRmut respectively into HTMC. pDsRed2-N1 was taken as internal reference. After 48 h transfection, the absorbance of EGFP and red fluorescent protein (REP) was detected with fluorescence spectrophotometer to explore the effect of miR-1 on FN expression. HTMC was stimulated with 200 μmol/L H(2)O(2) for 24 h after overexpression plasmid of miR-1 was transfected into it, and then FN mRNA and protein levels were detected via real time PCR, Western blotting and immunofluorescence. Data were analyzed via one-way analysis of variance or t test. Results: With the increase of H(2)O(2) concentration, miR-1 decreased (F=390.80, P<0.01) while FN increased (F=13.16, P<0.01). The level of miR-1 in HTMC stimulated by 200 μmol/L and 400 μmol/L H(2)O(2) decreased to 0.608±0.014 (t=21.67, P<0.01) and 0.409±0.020 (t=29.91, P<0.01), respectively, compared with untreated control cells (1.000); whereas, the mRNA levels of FN increased to 1.630±0.233 (t=4.47, P=0.011) and 1.903±0.246 (t=6.15, P=0.003), respectively, compared with untreated control cells(1.000). Through bioinformatics analysis, miR-1 might have candidate binding site in FN mRNA 3'-UTR. Meanwhile, these cells co-transfected with pcDNA3/pri-miR-1 and pcDNA3/EGFP-FN-3'UTRmut (0.562±0.018) had higher EGFP expression than cells co-transfected with pcDNA3/pri-miR-1 and pcDNA3/EGFP-FN-3'UTR (0.329±0.015) (t=17.39, P<0.01). Compared with the control (1.000), after overexpressing miR-1 the mRNA expression and the protein level of FN decreased to 0.294±0.081 (t=11.01, P<0.01) and 0.584±0.022 (t=5.57, P<0.01), respectively. Conclusions: MiR-1 decreases while FN increased in HTMC under oxidative stress. MiR-1 inhibits FN expression through targeting FN 3'-UTR. (Chin J Ophthalmol, 2019, 55: 355-360).
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Differentially expressed plasma proteins of β-thalassemia/hemoglobin E patients in response to curcuminoids/vitamin E antioxidant cocktails.
Panachan, J, Chokchaichamnankit, D, Weeraphan, C, Srisomsap, C, Masaratana, P, Hatairaktham, S, Panichkul, N, Svasti, J, Kalpravidh, RW
Hematology (Amsterdam, Netherlands). 2019;(1):300-307
Abstract
OBJECTIVE Iron overload and oxidative stress are the major causes of serious complications and mortality in thalassemic patients. Our previous work supports the synergistic effects of antioxidant cocktails (curcuminoids or vitamin E, N-acetylcysteine, and deferiprone) in treatment of β-thalassemia/Hb E patients. This further 2-DE-based proteomic study aimed to identify the plasma proteins that expressed differentially in response to antioxidant cocktails. METHODS Frozen plasma samples of ten normal subjects and ten β-thalassemia/Hb E patients at three-time points (baseline, month 6, and month 12) were reduced the dynamic range of proteome using ProteoMiner kit and separated proteins by two-dimensional gel electrophoresis. Differentially expressed proteins were identified using tandem mass spectrometry. Several plasma proteins were validated by ELISA and Western blot analysis. RESULTS Thirteen and 11 proteins were identified with altered expression levels in the curcuminoids- and vitamin E cocktail groups, respectively. The associations between vitronectin (VTN) expression and total bilirubin levels, as well as between serum paraoxonase/arylesterase 1 (PON1) expression and blood reactive oxygen species were observed. Validation results were consistent with proteomics results. DISCUSSION AND CONCLUSIONS These plasma proteins may provide better understanding of the mechanisms underlying the therapeutic effects of antioxidant cocktails in thalassemic patients.
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Branched-chain amino acid and branched-chain ketoacid ingestion increases muscle protein synthesis rates in vivo in older adults: a double-blind, randomized trial.
Fuchs, CJ, Hermans, WJH, Holwerda, AM, Smeets, JSJ, Senden, JM, van Kranenburg, J, Gijsen, AP, Wodzig, WKHW, Schierbeek, H, Verdijk, LB, et al
The American journal of clinical nutrition. 2019;(4):862-872
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Abstract
BACKGROUND Protein ingestion increases muscle protein synthesis rates. However, limited data are currently available on the effects of branched-chain amino acid (BCAA) and branched-chain ketoacid (BCKA) ingestion on postprandial muscle protein synthesis rates. OBJECTIVE The aim of this study was to compare the impact of ingesting 6 g BCAA, 6 g BCKA, and 30 g milk protein (MILK) on the postprandial rise in circulating amino acid concentrations and subsequent myofibrillar protein synthesis rates in older males. METHODS In a parallel design, 45 older males (age: 71 ± 1 y; BMI: 25.4 ± 0.8 kg/m2) were randomly assigned to ingest a drink containing 6 g BCAA, 6 g BCKA, or 30 g MILK. Basal and postprandial myofibrillar protein synthesis rates were assessed by primed continuous l-[ring-13C6]phenylalanine infusions with the collection of blood samples and muscle biopsies. RESULTS Plasma BCAA concentrations increased following test drink ingestion in all groups, with greater increases in the BCAA and MILK groups compared with the BCKA group (P < 0.05). Plasma BCKA concentrations increased following test drink ingestion in all groups, with greater increases in the BCKA group compared with the BCAA and MILK groups (P < 0.05). Ingestion of MILK, BCAA, and BCKA significantly increased early myofibrillar protein synthesis rates (0-2 h) above basal rates (from 0.020 ± 0.002%/h to 0.042 ± 0.004%/h, 0.022 ± 0.002%/h to 0.044 ± 0.004%/h, and 0.023 ± 0.003%/h to 0.044 ± 0.004%/h, respectively; P < 0.001), with no differences between groups (P > 0.05). Myofibrillar protein synthesis rates during the late postprandial phase (2-5 h) remained elevated in the MILK group (0.039 ± 0.004%/h; P < 0.001), but returned to baseline values following BCAA and BCKA ingestion (0.024 ± 0.005%/h and 0.024 ± 0.005%/h, respectively; P > 0.05). CONCLUSIONS Ingestion of 6 g BCAA, 6 g BCKA, and 30 g MILK increases myofibrillar protein synthesis rates during the early postprandial phase (0-2 h) in vivo in healthy older males. The postprandial increase following the ingestion of 6 g BCAA and BCKA is short-lived, with higher myofibrillar protein synthesis rates only being maintained following the ingestion of an equivalent amount of intact milk protein. This trial was registered at Nederlands Trial Register (www.trialregister.nl) as NTR6047.
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Antiviral activity of bone morphogenetic proteins and activins.
Eddowes, LA, Al-Hourani, K, Ramamurthy, N, Frankish, J, Baddock, HT, Sandor, C, Ryan, JD, Fusco, DN, Arezes, J, Giannoulatou, E, et al
Nature microbiology. 2019;(2):339-351
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Abstract
Understanding the control of viral infections is of broad importance. Chronic hepatitis C virus (HCV) infection causes decreased expression of the iron hormone hepcidin, which is regulated by hepatic bone morphogenetic protein (BMP)/SMAD signalling. We found that HCV infection and the BMP/SMAD pathway are mutually antagonistic. HCV blunted induction of hepcidin expression by BMP6, probably via tumour necrosis factor (TNF)-mediated downregulation of the BMP co-receptor haemojuvelin. In HCV-infected patients, disruption of the BMP6/hepcidin axis and genetic variation associated with the BMP/SMAD pathway predicted the outcome of infection, suggesting that BMP/SMAD activity influences antiviral immunity. Correspondingly, BMP6 regulated a gene repertoire reminiscent of type I interferon (IFN) signalling, including upregulating interferon regulatory factors (IRFs) and downregulating an inhibitor of IFN signalling, USP18. Moreover, in BMP-stimulated cells, SMAD1 occupied loci across the genome, similar to those bound by IRF1 in IFN-stimulated cells. Functionally, BMP6 enhanced the transcriptional and antiviral response to IFN, but BMP6 and related activin proteins also potently blocked HCV replication independently of IFN. Furthermore, BMP6 and activin A suppressed growth of HBV in cell culture, and activin A inhibited Zika virus replication alone and in combination with IFN. The data establish an unappreciated important role for BMPs and activins in cellular antiviral immunity, which acts independently of, and modulates, IFN.
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STIM2 interacts with AMPK and regulates calcium-induced AMPK activation.
Chauhan, AS, Liu, X, Jing, J, Lee, H, Yadav, RK, Liu, J, Zhou, Y, Gan, B
FASEB journal : official publication of the Federation of American Societies for Experimental Biology. 2019;(2):2957-2970
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Abstract
AMPK is a crucial regulator of energy homeostasis that acts downstream of its upstream kinase liver kinase B1 (LKB1) and calcium/calmodulin-dependent protein kinase 2 (CaMKK2). LKB1 primarily phosphorylates AMPK after energy stress, whereas calcium-mediated activation of AMPK requires CaMKK2, although the regulatory mechanisms of calcium-mediated AMPK activation remain unclear. Using biochemical, microscopic, and genetic approaches, we demonstrate that the stromal interaction molecule (STIM)2, a calcium sensor, acts as a novel regulator of CaMKK2-AMPK signaling. We reveal that STIM2 interacts with AMPK and CaMKK2 and that the increase in intracellular calcium levels promotes AMPK colocalization and interaction with STIM2. We further show that STIM2 deficiency attenuates calcium-induced but not energy stress-induced AMPK activation, possibly by regulating the CaMKK2-AMPK interaction. Together, our results identify a previously unappreciated mechanism that modulates calcium-mediated AMPK activation.-Chauhan, A. S., Liu, X., Jing, J., Lee, H., Yadav, R. K., Liu, J., Zhou, Y., Gan B. STIM2 interacts with AMPK and regulates calcium-induced AMPK activation.