Displaying publications 1 - 20 of 34 in total

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  1. Intracellular and exosomal microRNAome profiling of human vascular smooth muscle cells during replicative senescence
    Nguyen DDN, Zain SM, Kamarulzaman MH, Low TY, Chilian WM, Pan Y, et al.
    Am J Physiol Heart Circ Physiol, 2021 10 01;321(4):H770-H783.
    PMID: 34506226 DOI: 10.1152/ajpheart.00058.2021
    Vascular aging is highly associated with cardiovascular morbidity and mortality. Although the senescence of vascular smooth muscle cells (VSMCs) has been well established as a major contributor to vascular aging, intracellular and exosomal microRNA (miRNA) signaling pathways in senescent VSMCs have not been fully elucidated. This study aimed to identify the differential expression of intracellular and exosomal miRNA in human VSMCs (hVSMCs) during replicative senescence. To achieve this aim, intracellular and exosomal miRNAs were isolated from hVSMCs and subsequently subjected to whole genome small RNA next-generation sequencing, bioinformatics analyses, and qPCR validation. Three significant findings were obtained. First, senescent hVSMC-derived exosomes tended to cluster together during replicative senescence and the molecular weight of the exosomal protein tumor susceptibility gene 101 (TSG-101) increased relative to the intracellular TSG-101, suggesting potential posttranslational modifications of exosomal TSG-101. Second, there was a significant decrease in both intracellular and exosomal hsa-miR-155-5p expression [n = 3, false discovery rate (FDR) < 0.05], potentially being a cell type-specific biomarker of hVSMCs during replicative senescence. Importantly, hsa-miR-155-5p was found to associate with cell-cycle arrest and elevated oxidative stress. Lastly, miRNAs from the intracellular pool, that is, hsa-miR-664a-3p, hsa-miR-664a-5p, hsa-miR-664b-3p, hsa-miR-4485-3p, hsa-miR-10527-5p, and hsa-miR-12136, and that from the exosomal pool, that is, hsa-miR-7704, were upregulated in hVSMCs during replicative senescence (n = 3, FDR < 0.05). Interestingly, these novel upregulated miRNAs were not functionally well annotated in hVSMCs to date. In conclusion, hVSMC-specific miRNA expression profiles during replicative senescence potentially provide valuable insights into the signaling pathways leading to vascular aging.NEW & NOTEWORTHY This is the first study on intracellular and exosomal miRNA profiling on human vascular smooth muscle cells during replicative senescence. Specific dysregulated sets of miRNAs were identified from human vascular smooth muscle cells. Hsa-miR-155-5p was significantly downregulated in both intracellular and exosomal hVSMCs, suggesting its crucial role in cellular senescence. Hsa-miR-155-5p might be the mediator in linking cellular senescence to vascular aging and atherosclerosis.
    Matched MeSH terms: DNA-Binding Proteins/metabolism
  2. Analysis of Hereditary Nonpolyposis Colorectal Cancer in Malay Cohorts using Immunohistochemical Screening
    Wan Juhari WK, Wan Abdul Rahman WF, Mohd Sidek AS, Abu Hassan MR, Ahmad Amin Noordin KB, Zakaria AD, et al.
    Asian Pac J Cancer Prev, 2015;16(9):3767-71.
    PMID: 25987035
    BACKGROUND: Lynch syndrome (LS) is an inherited predisposition to colorectal, endometrial (uterine) and other cancers. Although most cancers are not inherited, about 5 percent (%) of people who have colorectal or endometrial cancer have the Lynch syndrome. It involves the alteration of mismatch repair (MMR) genes; MLH1, MSH2, MSH6 or PMS2. In this study, we analyzed the expression of MMR proteins in colorectal cancer in a Malay cohort by immunohistochemistry.

    MATERIALS AND METHODS: A total of 17 patients were selected fulfilling one of the Bethesda criteria: colorectal cancer diagnosed in a patient aged less than 50 years old, having synchronous and metachronous colorectal cancer or with a strong family history. Immunohistochemical staining was performed on paraffin embedded tumour tissue samples using four antibodies: MLH1, MSH2, MSH6 and PMS2.

    RESULTS: Twelve out of 17 patients (70.6%) were noted to have a family history. A total of 41% (n=7) of the patients had abnormal immunohistochemical staining with one or more of the four antibodies. Loss of expression were noted in 13 tumour tissues with a negative staining score <4. Of 13 tumour tissues, four showed loss expression of MLH1. For PMS2, loss of expression were noted in five cases. Both MSH2 and MSH6 showed loss of expression in two tumour tissues respectively.

    CONCLUSIONS: Revised Bethesda criteria and immunohistochemical analysis constituted a convenient approach and is recommended to be a first-line screening for Lynch syndrome in Malay cohorts.

    Matched MeSH terms: DNA-Binding Proteins/metabolism
  3. Fulltext Gelam honey attenuated radiation-induced cell death in human diploid fibroblasts by promoting cell cycle progression and inhibiting apoptosis
    Tengku Ahmad TA, Jaafar F, Jubri Z, Abdul Rahim K, Rajab NF, Makpol S
    BMC Complement Altern Med, 2014;14:108.
    PMID: 24655584 DOI: 10.1186/1472-6882-14-108
    The interaction between ionizing radiation and substances in cells will induce the production of free radicals. These free radicals inflict damage to important biomolecules such as chromosomes, proteins and lipids which consequently trigger the expression of genes which are involved in protecting the cells or repair the oxidative damages. Honey has been known for its antioxidant properties and was used in medical and cosmetic products. Currently, research on honey is ongoing and diversifying. The aim of this study was to elucidate the role of Gelam honey as a radioprotector in human diploid fibroblast (HDFs) which were exposed to gamma-rays by determining the expression of genes and proteins involved in cell cycle regulation and cell death.
    Matched MeSH terms: DNA-Binding Proteins/metabolism
  4. Fulltext Novel discovery of Averrhoa bilimbi ethanolic leaf extract in the stimulation of brown fat differentiation program in combating diet-induced obesity
    Lau WK, Noruddin NAA, Ariffin AH, Mahmud MZ, Noor MHM, Amanah A, et al.
    BMC Complement Altern Med, 2019 Sep 05;19(1):243.
    PMID: 31488120 DOI: 10.1186/s12906-019-2640-3
    BACKGROUND: Brown adipocytes are known to promote energy expenditure and limit weight gain to combat obesity. Averrhoa bilimbi, locally called belimbing buluh (DBB), is mainly used as an ethnomedicine in the treatment of metabolic disorders including diabetes mellitus, hypertension and obesity. The present study aims to investigate the browning activity on white adipocytes by A. bilimbi leaf extract and to evaluate the potential mechanisms.

    METHODS: Ethanolic leaf extract of A. bilimbi was exposed to Myf5 lineage precursor cells to stimulate adipocyte differentiation. Protein expressions of brown adipocyte markers were determined through high content screening analysis and validated through western blotting. Mito Stress Test assay was conducted to evaluate the cellular oxygen consumption rate upon A. bilimbi treatment.

    RESULTS: A. bilimbi ethanolic leaf extract exhibited an adipogenesis effect similar to a PPARgamma agonist. It also demonstrated brown adipocyte differentiation in myoblastic Myf5-positive precursor cells. Expression of UCP1 and PRDM16 were induced. The basal metabolic rate and respiratory capacity of mitochondria were increased upon A. bilimbi treatment.

    CONCLUSIONS: The findings suggest that Averrhoa bilimbi ethanolic leaf extract induces adipocyte browning through PRDM16 activation and enhances mitochondria activity due to UCP1 up-regulation.

    Matched MeSH terms: DNA-Binding Proteins/metabolism
  5. Critical role of ARID3B in the expression of pro-apoptotic p53-target genes and apoptosis
    Pratama E, Tian X, Lestari W, Iseki S, Ichwan SJ, Ikeda MA
    Biochem Biophys Res Commun, 2015 Dec;468(1-2):248-54.
    PMID: 26519881 DOI: 10.1016/j.bbrc.2015.10.121
    ARID3A and ARID3B are transcriptional targets of p53. Recently, it has been reported that ARID3A plays a critical role in the transcriptional activation of pro-arrest p21 in response to DNA damage. However, the role of ARID3B in the p53 regulatory pathway remains poorly understood. Here we show that ARID3A and ARID3B specifically bind to putative ARID3-binding sites in p53 target genes in vitro and in vivo. ARID3B and, to a lesser extent, ARID3A silencing blocked transcriptional activation of pro-apoptotic p53 target genes, such as PUMA, PIG3, and p53. Furthermore, ectopic ARID3B, to a lesser extent, ARID3A expression activated the pro-apoptotic gene expression, and only ARID3B induced apoptosis. Finally, ARID3B but not ARID3A silencing blocked apoptosis induction following DNA damage. These results indicated that, although ARID3B and ARID3A share overlapping functions, ARID3B play a key role in the expression of pro-apoptotic p53-target genes and apoptosis.
    Matched MeSH terms: DNA-Binding Proteins/metabolism
  6. Abnormality in DNA-protein binding in ataxia-telangiectasia nuclear extracts
    Mohamed R, Lavin MF
    Biochem Biophys Res Commun, 1989 Feb 15;158(3):749-54.
    PMID: 2537634
    Anomalies in DNA replication, repair and recombination in ataxia-telangiectasia (A-T) point to a defect in structure or function of chromatin. In this study we have compared DNA-protein binding in nuclear extracts from control and A-T cells using two assay systems, filter-binding and DNA-accessibility. Interestingly, the extent of DNA protein binding over a range of protein concentration was significantly lower in A-T extracts. In addition the accessibility of the restriction enzyme Eco R1 to protein-bound plasmid was greater when A-T extracts were used. This is in keeping with the reduced binding observed in the filter-binding assay.
    Matched MeSH terms: DNA-Binding Proteins/metabolism*
  7. Purification and functional analysis of recombinant Acholeplasma laidlawii histone-like HU protein
    Levitskiy SA, Sycheva AM, Kharlampieva DD, Oberto J, Kamashev DE, Serebryakova MV, et al.
    Biochimie, 2011 Jul;93(7):1102-9.
    PMID: 21443922 DOI: 10.1016/j.biochi.2011.03.005
    HU is a most abundant DNA-binding protein in bacteria. This protein is conserved either in its heterodimeric form or in one of its homodimeric forms in all bacteria, in plant chloroplasts, and in some viruses. HU protein non-specifically binds and bends DNA as a hetero- or homodimer and can participate in DNA supercoiling and DNA condensation. It also takes part in some DNA functions such as replication, recombination, and repair. HU does not recognize any specific sequences but shows some specificity to cruciform DNA and to repair intermediates, e.g., nick, gap, bulge, 3'-overhang, etc. To understand the features of HU binding to DNA and repair intermediates, a fast and easy HU proteins purification procedure is required. Here we report overproduction and purification of the HU homodimers. The method of HU purification allows obtaining a pure recombinant non-tagged protein cloned in Escherichia coli. We applied this method for purification of Acholeplasma laidlawii HU and demonstrated that this protein possesses a DNA-binding activity and is free of contaminating nuclease activity. Besides that we have shown that expression of A. laidlawii ihf_hu gene in a slow-growing hupAB E. coli strain restores the wild-type growth indicating that aclHU can perform the basic functions of E. coli HU in vivo.
    Matched MeSH terms: DNA-Binding Proteins/metabolism*
  8. Rapamycin synergizes cisplatin sensitivity in basal-like breast cancer cells through up-regulation of p73
    Wong SW, Tiong KH, Kong WY, Yue YC, Chua CH, Lim JY, et al.
    Breast Cancer Res Treat, 2011 Jul;128(2):301-13.
    PMID: 20686837 DOI: 10.1007/s10549-010-1055-0
    Recent gene expression profiling studies have identified five breast cancer subtypes, of which the basal-like subtype is the most aggressive. Basal-like breast cancer poses serious clinical challenges as there are currently no targeted therapies available to treat it. Although there is increasing evidence that these tumors possess specific sensitivity to cisplatin, its success is often compromised due to its dose-limiting nephrotoxicity and the development of drug resistance. To overcome this limitation, our goal was to maximize the benefits associated with cisplatin therapy through drug combination strategies. Using a validated kinase inhibitor library, we showed that inhibition of the mTOR, TGFβRI, NFκB, PI3K/AKT, and MAPK pathways sensitized basal-like MDA-MB-468 cells to cisplatin treatment. Further analysis demonstrated that the combination of the mTOR inhibitor rapamycin and cisplatin generated significant drug synergism in basal-like MDA-MB-468, MDA-MB-231, and HCC1937 cells but not in luminal-like T47D or MCF-7 cells. We further showed that the synergistic effect of rapamycin plus cisplatin on basal-like breast cancer cells was mediated through the induction of p73. Depletion of endogenous p73 in basal-like cells abolished these synergistic effects. In conclusion, combination therapy with mTOR inhibitors and cisplatin may be a useful therapeutic strategy in the treatment of basal-like breast cancers.
    Matched MeSH terms: DNA-Binding Proteins/metabolism*
  9. Fulltext The nucleoprotein of influenza A virus induces p53 signaling and apoptosis via attenuation of host ubiquitin ligase RNF43
    Nailwal H, Sharma S, Mayank AK, Lal SK
    Cell Death Dis, 2015 May 21;6:e1768.
    PMID: 25996295 DOI: 10.1038/cddis.2015.131
    The interplay between influenza virus and host factors to support the viral life cycle is well documented. Influenza A virus (IAV) proteins interact with an array of cellular proteins and hijack host pathways which are at the helm of cellular responses to facilitate virus invasion. The multifaceted nature of the ubiquitination pathway for protein regulation makes it a vulnerable target of many viruses including IAV. To this end we conducted a yeast two-hybrid screen to search for cellular ubiquitin ligases important for influenza virus replication. We identified host protein, RING finger protein 43 (RNF43), a RING-type E3 ubiquitin ligase, as a novel interactor of nucleoprotein (NP) of IAV and an essential partner to induce NP-driven p53-mediated apoptosis in IAV-infected cells. In this study, we demonstrate that IAV leads to attenuation of RNF43 transcripts and hence its respective protein levels in the cellular milieu whereas in RNF43 depleted cells, viral replication was escalated several folds. Moreover, RNF43 polyubiquitinates p53 which further leads to its destabilization resulting in a decrease in induction of the p53 apoptotic pathway, a hitherto unknown process targeted by NP for p53 stabilization and accumulation. Collectively, these results conclude that NP targets RNF43 to modulate p53 ubiquitination levels and hence causes p53 stabilization which is conducive to an enhanced apoptosis level in the host cells. In conclusion, our study unravels a novel strategy adopted by IAV for utilizing the much conserved ubiquitin proteasomal pathway.
    Matched MeSH terms: DNA-Binding Proteins/metabolism*
  10. Fulltext Identification of a BET family bromodomain/casein kinase II/TAF-containing complex as a regulator of mitotic condensin function
    Kim HS, Mukhopadhyay R, Rothbart SB, Silva AC, Vanoosthuyse V, Radovani E, et al.
    Cell Rep, 2014 Mar 13;6(5):892-905.
    PMID: 24565511 DOI: 10.1016/j.celrep.2014.01.029
    Condensin is a central regulator of mitotic genome structure with mutants showing poorly condensed chromosomes and profound segregation defects. Here, we identify NCT, a complex comprising the Nrc1 BET-family tandem bromodomain protein (SPAC631.02), casein kinase II (CKII), and several TAFs, as a regulator of condensin function. We show that NCT and condensin bind similar genomic regions but only briefly colocalize during the periods of chromosome condensation and decondensation. This pattern of NCT binding at the core centromere, the region of maximal condensin enrichment, tracks the abundance of acetylated histone H4, as regulated by the Hat1-Mis16 acetyltransferase complex and recognized by the first Nrc1 bromodomain. Strikingly, mutants in NCT or Hat1-Mis16 restore the formation of segregation-competent chromosomes in cells containing defective condensin. These results are consistent with a model where NCT targets CKII to chromatin in a cell-cycle-directed manner in order to modulate the activity of condensin during chromosome condensation and decondensation.
    Matched MeSH terms: DNA-Binding Proteins/metabolism*
  11. Fulltext WDR5, ASH2L, and RBBP5 control the efficiency of FOS transcript processing
    Teoh PL, Sharrocks AD
    Cell Mol Biol Lett, 2014 Jun;19(2):215-32.
    PMID: 24715476 DOI: 10.2478/s11658-014-0190-8
    H3K4 trimethylation is strongly associated with active transcription. The deposition of this mark is catalyzed by SET-domain methyltransferases, which consist of a subcomplex containing WDR5, ASH2L, and RBBP5 (the WAR subcomplex); a catalytic SET-domain protein; and additional complexspecific subunits. The ERK MAPK pathway also plays an important role in gene regulation via phosphorylation of transcription factors, co-regulators, or histone modifier complexes. However, the potential interactions between these two pathways remain largely unexplored. We investigated their potential interplay in terms of the regulation of the immediate early gene (IEG) regulatory network. We found that depletion of components of the WAR subcomplex led to increased levels of unspliced transcripts of IEGs that did not necessarily reflect changes in their mature transcripts. This occurs in a manner independent from changes in the H3K4me3 levels at the promoter region. We focused on FOS and found that the depletion of WAR subcomplex components affected the efficiency of FOS transcript processing. Our findings show a new aspect of WAR subcomplex function in coordinating active transcription with efficient pre-mRNA processing.
    Matched MeSH terms: DNA-Binding Proteins/metabolism*
  12. Metabolic Control of Type 2 Diabetes by Targeting the GLUT4 Glucose Transporter: Intervention Approaches
    Alam F, Islam MA, Khalil MI, Gan SH
    Curr Pharm Des, 2016;22(20):3034-49.
    PMID: 26951104 DOI: 10.2174/1381612822666160307145801
    Type 2 diabetes mellitus (T2DM), the most common form of diabetes, is characterized by insulin resistance in the hepatic and peripheral tissues. Glucose transporter 4 (GLUT4) plays a major role in the pathophysiology of T2DM. Its defective expression or translocation to the peripheral cell plasma membrane in T2DM patients hinders the entrance of glucose into the cell for energy production. In addition to suitable drugs, an appropriate diet and/or exercise can be implemented to target the increase in GLUT4 expression, GLUT4 concentrations and GLUT4 translocation to the cell surface when managing the glucose metabolism of T2DM patients. In this review, we discussed successful intervention strategies that were individually administered or coupled with diet and/or exercise and affected the expression and translocation of GLUT4 in T2DM while reducing the excess glucose load from the blood. Additionally, some potentially good synthetic and natural compounds, which can activate the insulin-independent GLUT4 signaling pathways for the efficient management of T2DM, are highlighted as possible targets or emerging alternative sources for future anti-diabetic drug development.
    Matched MeSH terms: DNA-Binding Proteins/metabolism*
  13. Fulltext The use of protein-DNA, chromatin immunoprecipitation, and transcriptome arrays to describe transcriptional circuits in the dehydrated male rat hypothalamus
    Qiu J, Kleineidam A, Gouraud S, Yao ST, Greenwood M, Hoe SZ, et al.
    Endocrinology, 2014 Nov;155(11):4380-90.
    PMID: 25144923 DOI: 10.1210/en.2014-1448
    The supraoptic nucleus (SON) of the hypothalamus is responsible for maintaining osmotic stability in mammals through its elaboration of the antidiuretic hormone arginine vasopressin. Upon dehydration, the SON undergoes a function-related plasticity, which includes remodeling of morphology, electrical properties, and biosynthetic activity. This process occurs alongside alterations in steady state transcript levels, which might be mediated by changes in the activity of transcription factors. In order to identify which transcription factors might be involved in changing patterns of gene expression, an Affymetrix protein-DNA array analysis was carried out. Nuclear extracts of SON from dehydrated and control male rats were analyzed for binding to the 345 consensus DNA transcription factor binding sequences of the array. Statistical analysis revealed significant changes in binding to 26 consensus elements, of which EMSA confirmed increased binding to signal transducer and activator of transcription (Stat) 1/Stat3, cellular Myelocytomatosis virus-like cellular proto-oncogene (c-Myc)-Myc-associated factor X (Max), and pre-B cell leukemia transcription factor 1 sequences after dehydration. Focusing on c-Myc and Max, we used quantitative PCR to confirm previous transcriptomic analysis that had suggested an increase in c-Myc, but not Max, mRNA levels in the SON after dehydration, and we demonstrated c-Myc- and Max-like immunoreactivities in SON arginine vasopressin-expressing cells. Finally, by comparing new data obtained from Roche-NimbleGen chromatin immunoprecipitation arrays with previously published transcriptomic data, we have identified putative c-Myc target genes whose expression changes in the SON after dehydration. These include known c-Myc targets, such as the Slc7a5 gene, which encodes the L-type amino acid transporter 1, ribosomal protein L24, histone deactylase 2, and the Rat sarcoma proto-oncogene (Ras)-related nuclear GTPase.
    Matched MeSH terms: DNA-Binding Proteins/metabolism
  14. Sex-specific differences in cardiovascular and metabolic hormones with integrated signalling in the paraventricular nucleus of the hypothalamus
    Loewen SP, Paterson AR, Loh SY, Rogers MF, Hindmarch CCT, Murphy D, et al.
    Exp Physiol, 2017 11 01;102(11):1373-1379.
    PMID: 28762571 DOI: 10.1113/EP086436
    NEW FINDINGS: What is the topic of this review? We describe roles of crucial signalling molecules in the paraventricular nucleus of the hypothalamus and highlight recent data suggesting sex-specific changes in the expression of crucial signalling molecules and their receptors, which may underlie sex differences in both cardiovascular and metabolic function. What advances does it highlight? This review highlights the integrative capacity of the paraventricular nucleus in mediating cardiovascular and metabolic effects by integrating information from multiple signalling molecules. It also proposes that these signalling molecules have sex-specific differential gene expression, indicating the importance of considering these differences in our ongoing search to understand the female-male differences in the regulation of crucial autonomic systems. Many traditional cardiovascular hormones have been implicated in metabolic function. Conversely, many hormones traditionally involved in metabolic regulation have an effect on cardiovascular function. Many of these signalling molecules exert such effects through specific actions in the paraventricular nucleus, an integrative autonomic control centre located in the hypothalamus. Here, we focus on four cardiovascular/metabolic peptide hormones that signal within the paraventricular nucleus, namely angiotensin II, orexin, adiponectin and nesfatin-1. Each of these hormones has specific electrophysiological effects on paraventricular nucleus neurons that can be related to its physiological actions. In addition, we introduce preliminary transcriptomic data indicating that the genes for some of these hormones and their receptors have sex-specific differential expression.
    Matched MeSH terms: DNA-Binding Proteins/metabolism*
  15. The pattern and frequency of t(14;18) translocation and immunophenotype in Asian follicular lymphoma
    Peh SC, Shaminie J, Tai YC, Tan J, Gan SS
    Histopathology, 2004 Nov;45(5):501-10.
    PMID: 15500654
    Follicular lymphoma is frequently associated with t(14;18)(q32;q21) translocation. This study was undertaken to determine the pattern of Bcl-2, CD10 and Bcl-6 expression in relation to t(14;18) translocation in follicular lymphoma from a cohort of a multi-ethnic Asian population.
    Matched MeSH terms: DNA-Binding Proteins/metabolism
  16. Fulltext Combined protein- and nucleic acid-level effects of rs1143679 (R77H), a lupus-predisposing variant within ITGAM
    Maiti AK, Kim-Howard X, Motghare P, Pradhan V, Chua KH, Sun C, et al.
    Hum Mol Genet, 2014 Aug 1;23(15):4161-76.
    PMID: 24608226 DOI: 10.1093/hmg/ddu106
    Integrin alpha M (ITGAM; CD11b) is a component of the macrophage-1 antigen complex, which mediates leukocyte adhesion, migration and phagocytosis as part of the immune system. We previously identified a missense polymorphism, rs1143679 (R77H), strongly associated with systemic lupus erythematosus (SLE). However, the molecular mechanisms of this variant are incompletely understood. A meta-analysis of published and novel data on 28 439 individuals with European, African, Hispanic and Asian ancestries reinforces genetic association between rs1143679 and SLE [Pmeta = 3.60 × 10(-90), odds ratio (OR) = 1.76]. Since rs1143679 is in the most active region of chromatin regulation and transcription factor binding in ITGAM, we quantitated ITGAM RNA and surface protein levels in monocytes from patients with each rs1143679 genotype. We observed that transcript levels significantly decreased for the risk allele ('A') relative to the non-risk allele ('G'), in a dose-dependent fashion: ('AA' < 'AG' < 'GG'). CD11b protein levels in patients' monocytes were directly correlated with RNA levels. Strikingly, heterozygous individuals express much lower (average 10- to 15-fold reduction) amounts of the 'A' transcript than 'G' transcript. We found that the non-risk sequence surrounding rs1143679 exhibits transcriptional enhancer activity in vivo and binds to Ku70/80, NFKB1 and EBF1 in vitro, functions that are significantly reduced with the risk allele. Mutant CD11b protein shows significantly reduced binding to fibrinogen and vitronectin, relative to non-risk, both in purified protein and in cellular models. This two-pronged contribution (nucleic acid- and protein-level) of the rs1143679 risk allele to decreasing ITGAM activity provides insight into the molecular mechanisms of its potent association with SLE.
    Matched MeSH terms: DNA-Binding Proteins/metabolism
  17. Fulltext Aberrant Inflammasome Activation Characterizes Tuberculosis-Associated Immune Reconstitution Inflammatory Syndrome
    Tan HY, Yong YK, Shankar EM, Paukovics G, Ellegård R, Larsson M, et al.
    J Immunol, 2016 05 15;196(10):4052-63.
    PMID: 27076678 DOI: 10.4049/jimmunol.1502203
    Tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) complicates combination antiretroviral therapy (cART) in up to 25% of patients with HIV/TB coinfection. Monocytes and IL-18, a signature cytokine of inflammasome activation, are implicated in TB-IRIS pathogenesis. In this study, we investigated inflammasome activation both pre- and post-cART in TB-IRIS patients. HIV/TB patients exhibited higher proportions of monocytes expressing activated caspase-1 (casp1) pre-cART, compared with HIV patients without TB, and patients who developed TB-IRIS exhibited the greatest increase in casp1 expression. CD64(+) monocytes were a marker of increased casp1 expression. Furthermore, IL-1β, another marker of inflammasome activation, was also elevated during TB-IRIS. TB-IRIS patients also exhibited greater upregulation of NLRP3 and AIM2 inflammasome mRNA, compared with controls. Analysis of plasma mitochondrial DNA levels showed that TB-IRIS patients experienced greater cell death, especially pre-cART. Plasma NO levels were lower both pre- and post-cART in TB-IRIS patients, providing evidence of inadequate inflammasome regulation. Plasma IL-18 levels pre-cART correlated inversely with NO levels but positively with monocyte casp1 expression and mitochondrial DNA levels, and expression of IL-18Rα on CD4(+) T cells and NK cells was higher in TB-IRIS patients, providing evidence that IL-18 is a marker of inflammasome activation. We propose that inflammasome activation in monocytes/macrophages of HIV/TB patients increases with ineffective T cell-dependent activation of monocytes/macrophages, priming them for an excessive inflammatory response after cART is commenced, which is greatest in patients with TB-IRIS.
    Matched MeSH terms: DNA-Binding Proteins/metabolism
  18. Fulltext RSAD2 and AIM2 Modulate Coxsackievirus A16 and Enterovirus A71 Replication in Neuronal Cells in Different Ways That May Be Associated with Their 5' Nontranslated Regions
    Yogarajah T, Ong KC, Perera D, Wong KT
    J Virol, 2018 03 15;92(6).
    PMID: 29263272 DOI: 10.1128/JVI.01914-17
    Coxsackievirus A16 (CV-A16) and enterovirus A71 (EV-A71) are closely related enteroviruses that cause the same hand, foot, and mouth disease (HFMD), but neurological complications occur only very rarely in CV-A16 compared to EV-A71 infections. To elucidate host responses that may be able to explain these differences, we performed transcriptomic analysis and real-time quantitative PCR (RT-qPCR) in CV-A16-infected neuroblastoma cells (SK-N-SH), and the results showed that the radical S-adenosylmethionine domain containing 2 (RSAD2) was the highest upregulated gene in the antimicrobial pathway. Increased RSAD2 expression was correlated with reduced viral replication, while RSAD2 knockdown cells were correlated with increased replication. EV-A71 replication showed no apparent correlation to RSAD2 expressions. Absent in melanoma 2 (AIM2), which is associated with pyroptotic cell death, was upregulated in EV-A71-infected neurons but not in CV-A16 infection, suggesting that the AIM2 inflammasome played a significant role in suppressing EV-A71 replication. Chimeric viruses derived from CV-A16 and EV-A71 but containing swapped 5' nontranslated regions (5' NTRs) showed that RSAD2 expression/viral replication and AIM2 expression/viral replication patterns may be linked to the 5' NTRs of parental viruses. Differences in secondary structure of internal ribosomal entry sites within the 5' NTR may be responsible for these findings. Overall, our results suggest that CV-A16 and EV-A71 elicit different host responses to infection, which may help explain the apparent lower incidence of CV-A16-associated neurovirulence in HFMD outbreaks compared to EV-A71 infection.IMPORTANCE Although coxsackievirus A16 (CV-A16) and enterovirus A17 (EV-A71) both cause hand, foot, and mouth disease, EV-A71 has emerged as a leading cause of nonpolio, enteroviral fatal encephalomyelitis among young children. The significance of our research is in the identification of the possible differing and novel mechanisms of CV-A16 and EV-A71 inhibition in neuronal cells that may impact viral neuropathogenesis. We further showed that viral 5' NTRs may play significant roles in eliciting different host response mechanisms.
    Matched MeSH terms: DNA-Binding Proteins/metabolism*
  19. Isolation and characterization of two ABRE-binding proteins: EABF and EABF1 from the oil palm
    Omidvar V, Abdullah SN, Ho CL, Mahmood M, Al-Shanfari AB
    Mol Biol Rep, 2012 Sep;39(9):8907-18.
    PMID: 22722992 DOI: 10.1007/s11033-012-1758-x
    Abscisic acid (ABA) is an important phytohormone involved in the abiotic stress resistance in plants. The ABA-responsive element (ABRE) binding factors play significant roles in the plant development and response to abiotic stresses, but none so far have been isolated and characterized from the oil palm. Two ABA-responsive cDNA clones, named EABF and EABF1, were isolated from the oil palm fruits using yeast one-hybrid system. The EABF had a conserved AP2/EREBP DNA-binding domain (DNA-BD) and a potential nuclear localization sequence (NLS). No previously known DNA-BD was identified from the EABF1 sequence. The EABF and EABF1 proteins were classified as DREB/CBF and bZIP family members based on the multiple sequence alignment and phylogenetic analysis. Both proteins showed ABRE-binding and transcriptional activation properties in yeast. Furthermore, both proteins were able to trans-activate the down-stream expression of the LacZ reporter gene in yeast. An electrophoretic mobility shift assay revealed that in addition to the ABRE sequence, both proteins could bind to the DRE sequence as well. Transcriptional analysis revealed that the expression of EABF was induced in response to the ABA in the oil palm fruits and leaves, but not in roots, while the EABF1 was constitutively induced in all tissues. The expressions of both genes were strongly induced in fruits in response to the ABA, ethylene, methyl jasmonate, drought, cold and high-salinity treatments, indicating that the EABF and EABF1 might act as connectors among different stress signal transduction pathways. Our results indicate that the EABF and EABF1 are novel stress-responsive transcription factors, which are involved in the abiotic stress response and ABA signaling in the oil palm and could be used for production of stress-tolerant transgenic crops.
    Matched MeSH terms: DNA-Binding Proteins/metabolism*
  20. Lauric acid alleviates insulin resistance by improving mitochondrial biogenesis in THP-1 macrophages
    Tham YY, Choo QC, Muhammad TST, Chew CH
    Mol Biol Rep, 2020 Dec;47(12):9595-9607.
    PMID: 33259010 DOI: 10.1007/s11033-020-06019-9
    Mitochondrial dysfunction plays a crucial role in the central pathogenesis of insulin resistance and type 2 diabetes mellitus. Macrophages play important roles in the pathogenesis of insulin resistance. Lauric acid is a 12-carbon medium chain fatty acid (MCFA) found abundantly in coconut oil or palm kernel oil and it comes with multiple beneficial effects. This research objective was to uncover the effects of the lauric acid on glucose uptake, mitochondrial function and mitochondrial biogenesis in insulin-resistant macrophages. THP-1 monocytes were differentiated into macrophages and induce insulin resistance, before they were treated with increasing doses of lauric acid (5 μM, 10 μM, 20 μM, and 50 μM). Glucose uptake assay, cellular ROS and ATP production assays, mitochondrial content and membrane potential assay were carried out to analyse the effects of lauric acid on insulin resistance and mitochondrial biogenesis in the macrophages. Quantitative RT-PCR (qRT-PCR) and western blot analysis were also performed to determine the expression of the key regulators. Insulin-resistant macrophages showed lower glucose uptake, GLUT-1 and GLUT-3 expression, and increased hallmarks of mitochondrial dysfunction. Interestingly, lauric acid treatment upregulated glucose uptake, GLUT-1 and GLUT-3 expressions. The treatment also restored the mitochondrial biogenesis in the insulin-resistant macrophages by improving ATP production, oxygen consumption, mitochondrial content and potential, while it promoted the expression of mitochondrial biogenesis regulator genes such as TFAM, PGC-1α and PPAR-γ. We show here that lauric acid has the potential to improve insulin sensitivity and mitochondrial dysregulation in insulin-resistant macrophages.
    Matched MeSH terms: DNA-Binding Proteins/metabolism
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