Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 32
Filter
1.
Hum Genet ; 143(1): 1-17, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37999799

ABSTRACT

Diabetes mellitus (DM) has become a significant health concern with an increasing rate of morbidity and mortality worldwide. India ranks second in the number of diabetes cases in the world. The increasing burden of DM can be explained by genetic predisposition of Indians to type 2 diabetes mellitus (T2DM) coupled with rapid urbanization and socio-economic development in the last 3 decades leading to drastic changes in lifestyle. Environment and lifestyle changes contribute to T2DM development by altering epigenetic processes such as DNA methylation, histone post-translational modifications, and long non-coding RNAs, all of which regulate chromatin structure and gene expression. Although the genetic predisposition of Indians to T2DM is well established, how environmental and genetic factors interact and lead to T2DM is not well understood. In this review, we discuss the prevalence of diabetes and its complications across different states in India and how various risk factors contribute to its pathogenesis. The review also highlights the role of genetic predisposition among the Indian population and epigenetic factors involved in the etiology of diabetes. Lastly, we review current treatments and emphasize the knowledge gap with respect to genetic and epigenetic factors in the Indian context. Further understanding of the genetic and epigenetic determinants will help in risk prediction and prevention as well as therapeutic interventions, which will improve the clinical management of diabetes and associated macro- and micro-vascular complications.


Subject(s)
Diabetes Complications , Diabetes Mellitus, Type 2 , Humans , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/epidemiology , Epigenesis, Genetic , DNA Methylation , Histones/genetics , Genetic Predisposition to Disease , India/epidemiology , Diabetes Complications/complications , Diabetes Complications/epidemiology , Diabetes Complications/genetics
2.
Arterioscler Thromb Vasc Biol ; 43(7): 1157-1175, 2023 07.
Article in English | MEDLINE | ID: mdl-37128912

ABSTRACT

BACKGROUND: Obesity and diabetes are associated with elevated free fatty acids like palmitic acid (PA), which promote chronic inflammation and impaired inflammation resolution associated with cardiometabolic disorders. Long noncoding RNAs (lncRNAs) are implicated in inflammatory processes; however, their roles in PA-regulated inflammation and resolution are unclear. METHODS: We performed RNA-sequencing analysis to identify PA-regulated coding genes and novel lncRNAs in CD14+ monocytes from healthy volunteers. We investigated the regulation and function of an uncharacterized PA-induced lncRNA PARAIL (PA-regulated anti-inflammatory lncRNA). We examined its role in inflammation resolution by employing knockdown and overexpression strategies in human and mouse macrophages. We also used RNA pulldown coupled with mass spectrometry to identify PARAIL interacting nuclear proteins and their mechanistic involvement in PARAIL functions in human macrophages. RESULTS: Treatment of human CD14+ monocytes with PA-induced several lncRNAs and genes associated with inflammatory phenotype. PA strongly induced lncRNA PARAIL expressed near RIPK2. PARAIL was also induced by cytokines and infectious agents in human monocytes/macrophages and was regulated by NF-κB (nuclear factor-kappa B). Time course studies showed PARAIL was induced during inflammation resolution phase in PA-treated macrophages. PARAIL knockdown with antisense oligonucleotides upregulated key inflammatory genes and vice versa with PARAIL overexpression. We found that PARAIL interacts with ELAVL1 (ELAV-like RNA-binding protein 1) protein via adenylate/uridylate-rich elements (AU-rich elements; AREs). ELAVL1 knockdown inhibited the anti-inflammatory functions of PARAIL. Moreover, PARAIL knockdown increased cytosolic localization of ELAVL1 and increased the stability of ARE-containing inflammatory genes. Mouse orthologous Parail was downregulated in macrophages from mice with diabetes and atherosclerosis. Parail overexpression attenuated proinflammatory genes in mouse macrophages. CONCLUSIONS: Upregulation of PARAIL under acute inflammatory conditions contributes to proresolution mechanisms via PARAIL-ELAVL1 interactions. Conversely, PARAIL downregulation in cardiometabolic diseases enhances ELAVL1 function and impairs inflammation resolution to further augment inflammation. Thus, inflammation-resolving lncRNAs like PARAIL represent novel targets to combat inflammatory cardiometabolic diseases.


Subject(s)
Atherosclerosis , RNA, Long Noncoding , Humans , Mice , Animals , Monocytes/metabolism , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Palmitic Acid/toxicity , Palmitic Acid/metabolism , Macrophages/metabolism , Inflammation/chemically induced , Inflammation/genetics , Inflammation/metabolism , NF-kappa B/metabolism , Atherosclerosis/metabolism , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , ELAV-Like Protein 1/genetics , ELAV-Like Protein 1/metabolism
3.
Inj Prev ; 2023 Nov 28.
Article in English | MEDLINE | ID: mdl-38050086

ABSTRACT

INTRODUCTION: Road traffic injuries (RTIs), particularly motorbike injuries, are one of the leading causes of death worldwide and have been a serious concern in low- and middle-income countries like Bangladesh. Therefore, this study aimed to assess the level of knowledge and practices on road safety measures among motorbikers in Dhaka, Bangladesh. METHODS: This cross-sectional study was conducted from January 2022 to December 2022 among 350 motorbikers of Dhaka city via a series of face-to-face interviews. Motorbikers who regularly ride a motorcycle were interviewed about their road safety knowledge and practices through a two-stage cluster sampling technique. Frequency distribution, independent sample t-test and one-way analysis of variance (ANOVA) were performed in data analysis. RESULTS: Out of the 350 motorbikers, only 54.6% had good knowledge and 16.9% had poor knowledge on the signs and safety regulations of roads. Moreover, only 50.6% of respondents followed good practices while 23.4% followed poor practices of road safety measures. One-way ANOVA analysis demonstrates that the average knowledge score was significantly (p<0.05) higher among higher-educated, unmarried and non-smokers. Additionally, higher education level, non-smoking status and being Muslim were significantly (p<0.05) associated with good road safety practices. CONCLUSIONS: The overall good knowledge level and practices of road safety measures among the motorbikers was not satisfactory although the majority of them knew individual signs and regulations. Therefore, this study suggests that education and strict enforcement of traffic rules may increase their knowledge and practice behaviour regarding road safety which in turn would minimise traffic injuries and fatalities.

4.
Arterioscler Thromb Vasc Biol ; 40(4): 914-928, 2020 04.
Article in English | MEDLINE | ID: mdl-32078363

ABSTRACT

OBJECTIVE: Systemic low-grade inflammation associated with obesity and metabolic syndrome is a strong risk factor for the development of diabetes mellitus and associated cardiovascular complications. This inflammatory state is caused by release of proinflammatory cytokines by macrophages, especially in adipose tissue. Long noncoding RNAs regulate macrophage activation and inflammatory gene networks, but their role in macrophage dysfunction during diet-induced obesity has been largely unexplored. Approach and Results: We sequenced total RNA from peritoneal macrophages isolated from mice fed either high-fat diet or standard diet and performed de novo transcriptome assembly to identify novel differentially expressed mRNAs and long noncoding RNAs. A top candidate long noncoding RNA, macrophage inflammation-suppressing transcript (Mist), was downregulated in both peritoneal macrophages and adipose tissue macrophages from high-fat diet-fed mice. GapmeR-mediated Mist knockdown in vitro and in vivo upregulated expression of genes associated with immune response and inflammation and increased modified LDL (low-density lipoprotein) uptake in macrophages. Conversely, Mist overexpression decreased basal and LPS (lipopolysaccharide)-induced expression of inflammatory response genes and decreased modified LDL uptake. RNA-pull down coupled with mass spectrometry showed that Mist interacts with PARP1 (poly [ADP]-ribose polymerase-1). Disruption of this RNA-protein interaction increased PARP1 recruitment and chromatin PARylation at promoters of inflammatory genes, resulting in increased gene expression. Furthermore, human orthologous MIST was also downregulated by proinflammatory stimuli, and its expression in human adipose tissue macrophages inversely correlated with obesity and insulin resistance. CONCLUSIONS: Mist is a novel protective long noncoding RNA, and its loss during obesity contributes to metabolic dysfunction and proinflammatory phenotype of macrophages via epigenetic mechanisms.


Subject(s)
Inflammation/physiopathology , Macrophage Activation/genetics , Obesity/genetics , Obesity/physiopathology , RNA, Long Noncoding/physiology , Adipose Tissue/metabolism , Animals , Cell Line , Cholesterol, LDL/metabolism , Chromatin/genetics , Cytokines/physiology , Down-Regulation , Humans , Lipid Metabolism/genetics , Male , Metabolic Syndrome/genetics , Metabolic Syndrome/physiopathology , Mice, Inbred C57BL , Poly (ADP-Ribose) Polymerase-1/genetics , Poly ADP Ribosylation , Up-Regulation
5.
J Biol Chem ; 294(34): 12695-12707, 2019 08 23.
Article in English | MEDLINE | ID: mdl-31266808

ABSTRACT

Transforming growth factor-ß1 (TGF-ß)-induced fibrotic and inflammatory genes in renal mesangial cells (MCs) play important roles in glomerular dysfunction associated with diabetic nephropathy (DN). TGF-ß regulates gene expression in MCs by altering key chromatin histone modifications at target gene promoters. However, the role of the repressive histone H3 lysine 27 trimethylation (H3K27me3) modification is unclear. Here we show that TGF-ß reduces H3K27me3 at the Ctgf, Serpine1, and Ccl2 gene promoters in rat MCs (RMCs) and reciprocally up-regulates the expression of these pro-fibrotic and inflammatory genes. In parallel, TGF-ß down-regulates Enhancer of Zeste homolog 2 (Ezh2), an H3K27me3 methyltransferase, and decreases its recruitment at Ctgf and Ccl2 but not Serpine1 promoters. Ezh2 knockdown with siRNAs enhances TGF-ß-induced expression of these genes, supporting its repressive function. Mechanistically, Ezh2 down-regulation is mediated by TGF-ß-induced microRNA, miR-101b, which targets Ezh2 3'-UTR. TGF-ß also up-regulates Jmjd3 and Utx in RMCs, suggesting a key role for these H3K27me3 demethylases in H3K27me3 inhibition. In RMCs, Utx knockdown inhibits hypertrophy, a key event in glomerular dysfunction. The H3K27me3 regulators are similarly altered in human and mouse MCs. High glucose inhibits Ezh2 and increases miR-101b in a TGF-ß-dependent manner. Furthermore, in kidneys from rodent models of DN, fibrotic genes, miR-101b, and H3K27me3 demethylases are up-regulated, whereas Ezh2 protein levels as well as enrichment of Ezh2 and H3K27me3 at target genes are decreased, demonstrating in vivo relevance. These results suggest that H3K27me3 inhibition by TGF-ß via dysregulation of related histone-modifying enzymes and miRNAs augments pathological genes mediating glomerular mesangial dysfunction and DN.


Subject(s)
Diabetes Mellitus, Type 1/metabolism , Diabetic Nephropathies/metabolism , Gene Expression Regulation , Histones/metabolism , Lysine/metabolism , Mesangial Cells/metabolism , Transforming Growth Factor beta1/metabolism , Animals , Cells, Cultured , Diabetes Mellitus, Type 1/chemically induced , Diabetes Mellitus, Type 1/genetics , Diabetic Nephropathies/chemically induced , Diabetic Nephropathies/genetics , Humans , Injections, Intraperitoneal , Male , Methylation , Mice , Mice, Inbred C57BL , Rats , Rats, Sprague-Dawley , Streptozocin/administration & dosage
6.
Curr Opin Cardiol ; 35(3): 234-241, 2020 05.
Article in English | MEDLINE | ID: mdl-32205477

ABSTRACT

PURPOSE OF REVIEW: Hyperlipidemia, hypertension, diabetes and related metabolic disorders increase the risk for cardiovascular disease (CVD). Despite significant progress in the identification of key mechanisms and genetic polymorphisms linked to various CVDs, the rates of CVDs continue to escalate, underscoring the need to evaluate additional mechanisms for more effective therapies. Environment and lifestyle changes can alter epigenetic mechanisms mediated by histone modifications and long noncoding RNAs (lncRNAs) which play important roles in gene regulation. The review summarizes recent findings on the role of epigenetic mechanisms in CVD. RECENT FINDINGS: Recent studies identified dysregulated histone modifications and chromatin modifying proteins at cis-regulatory elements, including enhancers/super-enhancers, mediating the expression of genes associated with CVD in vascular and immune cells in response to growth factors and inflammatory mediators. Several lncRNAs have also been reported to contribute to pathological gene expression via cis and trans mechanisms involving interactions with nuclear proteins, co-operation with enhancers/super enhancers and acting as microRNA sponges. SUMMARY: Epigenomic approaches in cells affected in CVDs can be exploited to understand the function of genetic polymorphisms at cis-regulatory elements and crosstalk between enhancers and lncRNAs associated with disease susceptibility and progression. The reversible nature of epigenetics provides opportunities for the development of novel therapeutic strategies for CVD.


Subject(s)
Cardiovascular Diseases/genetics , RNA, Long Noncoding/genetics , Epigenesis, Genetic , Humans
7.
Circ Res ; 123(12): 1298-1312, 2018 12 07.
Article in English | MEDLINE | ID: mdl-30566058

ABSTRACT

RATIONALE: AngII (angiotensin II)-mediated vascular smooth muscle cell (VSMC) dysfunction plays a major role in hypertension. Long noncoding RNAs have elicited much interest, but their molecular roles in AngII actions and hypertension are unclear. OBJECTIVE: To investigate the regulation and functions of a novel long noncoding RNA growth factor- and proinflammatory cytokine-induced vascular cell-expressed RNA ( Giver), in AngII-mediated VSMC dysfunction. METHODS AND RESULTS: RNA-sequencing and real-time quantitative polymerase chain reactions revealed that treatment of rat VSMC with AngII increased the expression of Giver and Nr4a3, an adjacent gene encoding a nuclear receptor. Similar changes were observed in rat and mouse aortas treated ex vivo with AngII. RNA-FISH (fluorescence in situ hybridization) and subcellular fractionation showed predominantly nuclear localization of Giver. AngII increased Giver expression via recruitment of Nr4a3 to Giver promoter. Microarray profiling and real-time quantitative polymerase chain reaction validation in VSMC showed that Giver knockdown attenuated the expression of genes involved in oxidative stress ( Nox1) and inflammation ( Il6, Ccl2, Tnf) but increased Nr4a3. Conversely, endogenous Giver overexpression showed opposite effects supporting its role in oxidative stress and inflammation. Chromatin immunoprecipitation assays showed Giver overexpression also increased Pol II (RNA polymerase II) enrichment and decreased repressive histone modification histone H3 trimethylation on lysine 27 at Nox1 and inflammatory gene promoters. Accordingly, Giver knockdown inhibited AngII-induced oxidative stress and proliferation in rat VSMC. RNA-pulldown combined with mass spectrometry showed Giver interacts with nuclear and chromatin remodeling proteins and corepressors, including NONO (non-pou domain-containing octamer-binding protein). Moreover, NONO knockdown elicited similar effects as Giver knockdown on the expression of key Giver-regulated genes. Notably, GIVER and NR4A3 were increased in AngII-treated human VSMC and in arteries from hypertensive patients but attenuated in hypertensive patients treated with ACE (angiotensin-converting enzyme) inhibitors or angiotensin receptor blockers. Furthermore, human GIVER also exhibits partial functional conservation with rat Giver. CONCLUSIONS: Giver and its regulator Nr4a3 are important players in AngII-mediated VSMC dysfunction and could be novel targets for antihypertensive therapy.


Subject(s)
Cell Proliferation , Cytokines/metabolism , Hypertension/metabolism , Muscle, Smooth, Vascular/metabolism , Oxidative Stress , RNA, Long Noncoding/genetics , Animals , Cells, Cultured , Humans , Hypertension/genetics , Male , Mice , Mice, Inbred C57BL , Muscle, Smooth, Vascular/cytology , Muscle, Smooth, Vascular/physiology , Myocytes, Smooth Muscle/metabolism , Myocytes, Smooth Muscle/physiology , NADPH Oxidase 1/genetics , NADPH Oxidase 1/metabolism , RNA, Long Noncoding/metabolism , Rats , Rats, Sprague-Dawley
8.
Arterioscler Thromb Vasc Biol ; 38(8): 1806-1820, 2018 08.
Article in English | MEDLINE | ID: mdl-29930005

ABSTRACT

Objective- Macrophages play key roles in inflammation and diabetic vascular complications. Emerging evidence implicates long noncoding RNAs in inflammation, but their role in macrophage dysfunction associated with inflammatory diabetic complications is unclear and was therefore investigated in this study. Approach and Results- RNA-sequencing and real-time quantitative PCR demonstrated that a long noncoding RNA Dnm3os (dynamin 3 opposite strand) is upregulated in bone marrow-derived macrophages from type 2 diabetic db/db mice, diet-induced insulin-resistant mice, and diabetic ApoE-/- mice, as well as in monocytes from type 2 diabetic patients relative to controls. Diabetic conditions (high glucose and palmitic acid) induced Dnm3os in mouse and human macrophages. Promoter reporter analysis and chromatin immunoprecipitation assays demonstrated that diabetic conditions induce Dnm3os via NF-κB activation. RNA fluorescence in situ hybridization and real-time quantitative PCRs of subcellular fractions demonstrated nuclear localization and chromatin enrichment of Dnm3os in macrophages. Stable overexpression of Dnm3os in macrophages altered global histone modifications and upregulated inflammation and immune response genes and phagocytosis. Conversely, RNAi-mediated knockdown of Dnm3os attenuated these responses. RNA pull-down assays with macrophage nuclear lysates identified nucleolin and ILF-2 (interleukin enhancer-binding factor 2) as protein binding partners of Dnm3os, which was further confirmed by RNA fluorescence in situ hybridization immunofluorescence. Furthermore, nucleolin levels were decreased in diabetic conditions, and its knockdown enhanced Dnm3os-induced inflammatory gene expression and histone H3K9-acetylation at their promoters. Conclusions- These results demonstrate novel mechanisms involving upregulation of long noncoding RNA Dnm3os, disruption of its interaction with nucleolin, and epigenetic modifications at target genes that promote macrophage inflammatory phenotype in diabetes mellitus. The data could lead to long noncoding RNA-based therapies for inflammatory diabetes mellitus complications.


Subject(s)
Cell Nucleus/metabolism , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Type 1/metabolism , Diabetes Mellitus, Type 2/metabolism , Inflammation/metabolism , Macrophage Activation , Macrophages/metabolism , RNA, Long Noncoding/metabolism , Animals , Case-Control Studies , Cell Nucleus/genetics , Diabetes Mellitus, Experimental/chemically induced , Diabetes Mellitus, Experimental/genetics , Diabetes Mellitus, Type 1/chemically induced , Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 2/genetics , Epigenesis, Genetic , Female , Humans , Inflammation/genetics , Inflammation Mediators/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout, ApoE , Phagocytosis , Phenotype , Phosphoproteins/metabolism , Protein Binding , RAW 264.7 Cells , RNA, Long Noncoding/genetics , RNA-Binding Proteins/metabolism , Signal Transduction , Streptozocin , Up-Regulation , Nucleolin
9.
Plant Cell ; 26(3): 1330-44, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24668745

ABSTRACT

In plants as well as in animals, hundreds to thousands of 45S rRNA gene copies localize in Nucleolus Organizer Regions (NORs), and the activation or repression of specific sets of rDNA depends on epigenetic mechanisms. Previously, we reported that the Arabidopsis thaliana nucleolin protein NUC1, an abundant and evolutionarily conserved nucleolar protein in eukaryotic organisms, is required for maintaining DNA methylation levels and for controlling the expression of specific rDNA variants in Arabidopsis. Interestingly, in contrast with animal or yeast cells, plants contain a second nucleolin gene. Here, we report that Arabidopsis NUC1 and NUC2 nucleolin genes are both required for plant growth and survival and that NUC2 disruption represses flowering. However, these genes seem to be functionally antagonistic. In contrast with NUC1, disruption of NUC2 induces CG hypermethylation of rDNA and NOR association with the nucleolus. Moreover, NUC2 loss of function triggers major changes in rDNA spatial organization, expression, and transgenerational stability. Our analyses indicate that silencing of specific rRNA genes is mostly determined by the active or repressed state of the NORs and that nucleolin proteins play a key role in the developmental control of this process.


Subject(s)
Arabidopsis/genetics , Chromatin/metabolism , DNA, Ribosomal/genetics , Gene Duplication , Phosphoproteins/genetics , RNA, Ribosomal/genetics , RNA-Binding Proteins/genetics , DNA Copy Number Variations , DNA Methylation , Genes, Plant , Promoter Regions, Genetic , Nucleolin
11.
Arterioscler Thromb Vasc Biol ; 36(5): 864-73, 2016 05.
Article in English | MEDLINE | ID: mdl-26941017

ABSTRACT

OBJECTIVE: Diabetes mellitus accelerates proatherogenic and proinflammatory phenotype of vascular smooth muscle cell (VSMC) associated with vascular complications. Evidence shows that microRNAs (miRNAs) play key roles in VSMC functions, but their role under diabetic conditions is unclear. We profiled miRNAs in VSMC from diabetic mice and examined their role in VSMC dysfunction. APPROACH AND RESULTS: High throughput small RNA-sequencing identified 135 differentially expressed miRNAs in VSMC from type 2 diabetic db/db mice (db/dbVSMC) versus nondiabetic db/+ mice. Several of these miRNAs were known to regulate VSMC functions. We further focused on miR-504, because it was highly upregulated in db/dbVSMC, and its function in VSMC is unknown. miR-504 and its host gene Fgf13 were significantly increased in db/dbVSMC and in aortas from db/db mice. Bioinformatics analysis predicted that miR-504 targets including signaling adaptor Grb10 and transcription factor Egr2 could regulate growth factor signaling. We experimentally validated Grb10 and Egr2 as novel targets of miR-504. Overexpression of miR-504 in VSMC inhibited contractile genes and enhanced extracellular signal-regulated kinase 1/2 activation, proliferation, and migration. These effects were blocked by miR-504 inhibitors. Grb10 knockdown mimicked miR-504 functions and increased inflammatory genes. Egr2 knockdown-inhibited anti-inflammatory Socs1 and increased proinflammatory genes. Furthermore, high glucose and palmitic acid upregulated miR-504 and inflammatory genes, but downregulated Grb10. CONCLUSIONS: Diabetes mellitus misregulates several miRNAs including miR-504 that can promote VSMC dysfunction. Because changes in many of these miRNAs are sustained in diabetic VSMC even after in vitro culture, they may be involved in metabolic memory of vascular complications. Targeting such mechanisms could offer novel therapeutic strategies for diabetic complications.


Subject(s)
Aortic Diseases/metabolism , Atherosclerosis/metabolism , Diabetes Mellitus, Type 2/metabolism , Diabetic Angiopathies/metabolism , MicroRNAs/metabolism , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , Animals , Aorta, Thoracic/metabolism , Aorta, Thoracic/pathology , Aortic Diseases/genetics , Aortic Diseases/pathology , Atherosclerosis/genetics , Atherosclerosis/pathology , Cell Movement , Cell Proliferation , Cells, Cultured , Computational Biology , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/pathology , Diabetic Angiopathies/genetics , Diabetic Angiopathies/pathology , Disease Models, Animal , Early Growth Response Protein 2/genetics , Early Growth Response Protein 2/metabolism , Extracellular Signal-Regulated MAP Kinases/metabolism , Fibroblast Growth Factors/genetics , Fibroblast Growth Factors/metabolism , GRB10 Adaptor Protein/genetics , GRB10 Adaptor Protein/metabolism , Gene Expression Profiling/methods , Gene Expression Regulation , Glucose/pharmacology , High-Throughput Nucleotide Sequencing , Male , MicroRNAs/genetics , Muscle, Smooth, Vascular/drug effects , Muscle, Smooth, Vascular/pathology , Myocytes, Smooth Muscle/drug effects , Myocytes, Smooth Muscle/pathology , Palmitic Acid/pharmacology , Phenotype , RNA Interference , Signal Transduction , Suppressor of Cytokine Signaling 1 Protein/genetics , Suppressor of Cytokine Signaling 1 Protein/metabolism , Transfection
12.
Nucleic Acids Res ; 42(1): 181-92, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24071584

ABSTRACT

The regulation of ribosomal DNA transcription is an important step for the control of cell growth. Epigenetic marks such as DNA methylation and posttranslational modifications of canonical histones have been involved in this regulation, but much less is known about the role of histone variants. In this work, we show that the histone variant macroH2A1 is present on the promoter of methylated rDNA genes. The inhibition of the expression of macroH2A1 in human HeLa and HepG2 cells and in a mouse ES cell line resulted in an up to 5-fold increase of pre-rRNA levels. This increased accumulation of pre-rRNA is accompanied by an increase of the loading of RNA polymerase I and UBF on the rDNA without any changes in the number of active rDNA genes. The inhibition of RNA polymerase I transcription by actinomycin D or by knocking down nucleolin, induces the recruitment of macroH2A1 on the rDNA and the relocalization of macroH2A1 in the nucleolus. Interestingly, the inhibition of rDNA transcription induced by nucleolin depletion is alleviated by the inactivation of macroH2A1. These results demonstrate that macroH2A1 is a new factor involved in the regulation of rDNA transcription.


Subject(s)
DNA, Ribosomal/metabolism , Gene Expression Regulation , Histones/metabolism , Repressor Proteins/metabolism , Transcription, Genetic , Animals , Cell Line , Cell Nucleolus/metabolism , DNA Methylation , HeLa Cells , Humans , Mice , Phosphoproteins/metabolism , RNA-Binding Proteins/metabolism , Nucleolin
13.
Nucleic Acids Res ; 40(19): 9441-54, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22859736

ABSTRACT

Nucleolin is a multi-functional nucleolar protein that is required for ribosomal RNA gene (rRNA) transcription in vivo, but the mechanism by which nucleolin modulates RNA polymerase I (RNAPI) transcription is not well understood. Nucleolin depletion results in an increase in the heterochromatin mark H3K9me2 and a decrease in H4K12Ac and H3K4me3 euchromatin histone marks in rRNA genes. ChIP-seq experiments identified an enrichment of nucleolin in the ribosomal DNA (rDNA) coding and promoter region. Nucleolin is preferentially associated with unmethylated rRNA genes and its depletion leads to the accumulation of RNAPI at the beginning of the transcription unit and a decrease in UBF along the coding and promoter regions. Nucleolin is able to affect the binding of transcription termination factor-1 on the promoter-proximal terminator T0, thus inhibiting the recruitment of TIP5 and HDAC1 and the establishment of a repressive heterochromatin state. These results reveal the importance of nucleolin for the maintenance of the euchromatin state and transcription elongation of rDNA.


Subject(s)
Genes, rRNA , Phosphoproteins/metabolism , RNA Polymerase I/metabolism , RNA-Binding Proteins/metabolism , Transcription, Genetic , Chromatin/metabolism , DNA, Ribosomal/chemistry , DNA, Ribosomal/metabolism , DNA-Binding Proteins/metabolism , Epigenesis, Genetic , HeLa Cells , Humans , Phosphoproteins/antagonists & inhibitors , Phosphoproteins/physiology , RNA-Binding Proteins/antagonists & inhibitors , RNA-Binding Proteins/physiology , Repetitive Sequences, Nucleic Acid , Terminator Regions, Genetic , Transcription Factors , Nucleolin
14.
J Biochem ; 175(2): 205-213, 2024 Feb 25.
Article in English | MEDLINE | ID: mdl-37963603

ABSTRACT

TFIIIC is a multi-subunit complex required for tRNA transcription by RNA polymerase III. Human TFIIIC holo-complex possesses lysine acetyltransferase activity that aids in relieving chromatin-mediated repression for RNA polymerase III-mediated transcription and chromatin assembly. Here we have characterized the acetyltransferase activity of the largest and DNA-binding subunit of TFIIIC complex, TFIIIC220. Purified recombinant human TFIIIC220 acetylated core histones H3, H4 and H2A in vitro. Moreover, we have identified the putative catalytic domain of TFIIIC220 that efficiently acetylates core histones in vitro. Mutating critical residues of the putative acetyl-CoA binding 'P loop' drastically reduced the catalytic activity of the acetyltransferase domain. Further analysis showed that the knockdown of TFIIIC220 in mammalian cell lines dramatically reduces global H3K18 acetylation level, which was rescued by overexpression of the putative acetyltransferase domain of human TFIIIC220. Our findings indicated a possibility of a crucial role for TFIIIC220 in maintaining acetylation homeostasis in the cell.


Subject(s)
Histones , Lysine Acetyltransferases , Transcription Factors, TFIII , Animals , Humans , Histones/metabolism , Lysine Acetyltransferases/metabolism , RNA Polymerase III/metabolism , Histone Acetyltransferases/genetics , Histone Acetyltransferases/metabolism , Acetylation , Mammals
15.
Front Mol Biosci ; 10: 1204124, 2023.
Article in English | MEDLINE | ID: mdl-37325470

ABSTRACT

Background: MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) play key roles in diabetic kidney disease (DKD). The miR-379 megacluster of miRNAs and its host transcript lnc-megacluster (lncMGC) are regulated by transforming growth factor-ß (TGF-ß), increased in the glomeruli of diabetic mice, and promote features of early DKD. However, biochemical functions of lncMGC are unknown. Here, we identified lncMGC-interacting proteins by in vitro-transcribed lncMGC RNA pull down followed by mass spectrometry. We also created lncMGC-knockout (KO) mice by CRISPR-Cas9 editing and used primary mouse mesangial cells (MMCs) from the KO mice to examine the effects of lncMGC on the gene expression related to DKD, changes in promoter histone modifications, and chromatin remodeling. Methods: In vitro-transcribed lncMGC RNA was mixed with lysates from HK2 cells (human kidney cell line). lncMGC-interacting proteins were identified by mass spectrometry. Candidate proteins were confirmed by RNA immunoprecipitation followed by qPCR. Cas9 and guide RNAs were injected into mouse eggs to create lncMGC-KO mice. Wild-type (WT) and lncMGC-KO MMCs were treated with TGF-ß, and RNA expression (by RNA-seq and qPCR) and histone modifications (by chromatin immunoprecipitation) and chromatin remodeling/open chromatin (by Assay for Transposase-Accessible Chromatin using sequencing, ATAC-seq) were examined. Results: Several nucleosome remodeling factors including SMARCA5 and SMARCC2 were identified as lncMGC-interacting proteins by mass spectrometry, and confirmed by RNA immunoprecipitation-qPCR. MMCs from lncMGC-KO mice showed no basal or TGF-ß-induced expression of lncMGC. Enrichment of histone H3K27 acetylation and SMARCA5 at the lncMGC promoter was increased in TGF-ß-treated WT MMCs but significantly reduced in lncMGC-KO MMCs. ATAC peaks at the lncMGC promoter region and many other DKD-related loci including Col4a3 and Col4a4 were significantly lower in lncMGC-KO MMCs compared to WT MMCs in the TGF-ß-treated condition. Zinc finger (ZF), ARID, and SMAD motifs were enriched in ATAC peaks. ZF and ARID sites were also found in the lncMGC gene. Conclusion: lncMGC RNA interacts with several nucleosome remodeling factors to promote chromatin relaxation and enhance the expression of lncMGC itself and other genes including pro-fibrotic genes. The lncMGC/nucleosome remodeler complex promotes site-specific chromatin accessibility to enhance DKD-related genes in target kidney cells.

16.
Appl Phys A Mater Sci Process ; 128(10): 866, 2022.
Article in English | MEDLINE | ID: mdl-36101661

ABSTRACT

In this work, a shock-free argon-fed plasma plume was generated by a variable-frequency power supply and the discharge characteristics were investigated from the voltage and current waveforms between 72 and 92 kHz frequencies. The higher electron temperature dominates the plasma chemical process and the average plasma temperature is about 30 â„ƒ under these conditions. The influence of non-thermal atmospheric plasma plume length and plume temperature on Ar gas flow is optimized at 7 sL/min. The average charge accumulation on the plume tip area and the dependence of flow rate on the plasma irradiation area were also explored. This atmospheric pressure plasma jet (APPJ) has been proposed for human-skin irradiation on different areas (even on the tongue) owing to its less painful, tingling and burning effect. Optical emission spectroscopy (OES) confirmed the presence of excited argon with reactive nitrogen (RNS) and oxygen species (ROS). This study contributes to a better understanding of non-thermal plasma effects on the human body which may find prospects for disinfection and prevention of different diseases during the current pandemic time. Supplementary Information: The online version contains supplementary material available at 10.1007/s00339-022-06022-w.

17.
Mol Cell Biol ; 42(2): e0066920, 2022 02 17.
Article in English | MEDLINE | ID: mdl-34898280

ABSTRACT

Nucleophosmin (NPM1) is a multifunctional histone chaperone that can activate acetylation-dependent transcription from chromatin templates in vitro. p300-mediated acetylation of NPM1 has been shown to further enhance its transcription activation potential. Acetylated and total NPM1 pools are increased in oral squamous cell carcinoma. However, the role of NPM1 or its acetylated form (AcNPM1) in transcriptional regulation in cells and oral tumorigenesis is not fully elucidated. Using ChIP-seq analyses, we provide the first genome-wide profile of AcNPM1 and show that AcNPM1 is enriched at transcriptional regulatory elements. AcNPM1 co-occupies marks of active transcription at promoters and DNase I hypersensitive sites at enhancers. In addition, using a high-throughput protein interaction profiling approach, we show that NPM1 interacts with RNA Pol II, general transcription factors, mediator subunits, histone acetyltransferase complexes, and chromatin remodelers. NPM1 histone chaperone activity also contributes to its transcription activation potential. Further, NPM1 depletion leads to decreased AcNPM1 occupancy and reduced expression of genes required for proliferative, migratory and invasive potential of oral cancer cells. NPM1 depletion also abrogates the growth of orthotopic tumors in mice. Collectively, these results establish that AcNPM1 functions as a coactivator during during RNA polymerase II-driven transcription and regulates the expression of genes that promote oral tumorigenesis.


Subject(s)
Carcinoma, Squamous Cell/metabolism , Gene Expression Regulation/physiology , Histone Chaperones/metabolism , Mouth Neoplasms/genetics , Nucleophosmin/metabolism , Animals , Carcinogenesis/metabolism , Carcinoma, Squamous Cell/genetics , Chromatin Assembly and Disassembly/genetics , Chromatin Assembly and Disassembly/physiology , Gene Expression Regulation/genetics , Histones/metabolism , Humans , Nuclear Proteins/metabolism , Promoter Regions, Genetic/genetics
18.
Materials (Basel) ; 14(12)2021 Jun 09.
Article in English | MEDLINE | ID: mdl-34207839

ABSTRACT

We report the surface stoichiometry of Tix-CuyNz thin film as a function of film depth. Films are deposited by high power impulse (HiPIMS) and DC magnetron sputtering (DCMS). The composition of Ti, Cu, and N in the deposited film is investigated by X-ray photoelectron spectroscopy (XPS). At a larger depth, the relative composition of Cu and Ti in the film is increased compared to the surface. The amount of adventitious carbon which is present on the film surface strongly decreases with film depth. Deposited films also contain a significant amount of oxygen whose origin is not fully clear. Grazing incidence X-ray diffraction (GIXD) shows a Cu3N phase on the surface, while transmission electron microscopy (TEM) indicates a polycrystalline structure and the presence of a Ti3CuN phase.

19.
Cells ; 10(10)2021 10 09.
Article in English | MEDLINE | ID: mdl-34685676

ABSTRACT

Long non-coding RNAs (lncRNAs) play key roles in Angiotensin II (AngII) signaling but their role in chondrogenic transformation of vascular smooth muscle cells (VSMCs) is unknown. We describe a novel AngII-induced lncRNA Alivec (Angiotensin II-induced lncRNA in VSMCs eliciting chondrogenic phenotype) implicated in VSMC chondrogenesis. In rat VSMCs, Alivec and the nearby gene Acan, a chondrogenic marker, were induced by growth factors AngII and PDGF and the inflammatory cytokine TNF-α. AngII co-regulated Alivec and Acan through the activation of AngII type1 receptor signaling and Sox9, a master transcriptional regulator of chondrogenesis. Alivec knockdown with GapmeR antisense-oligonucleotides attenuated the expression of AngII-induced chondrogenic marker genes, including Acan, and inhibited the chondrogenic phenotype of VSMCs. Conversely, Alivec overexpression upregulated these genes and promoted chondrogenic transformation. RNA-pulldown coupled to mass-spectrometry identified Tropomyosin-3-alpha and hnRNPA2B1 proteins as Alivec-binding proteins in VSMCs. Furthermore, male rats with AngII-driven hypertension showed increased aortic expression of Alivec and Acan. A putative human ortholog ALIVEC, was induced by AngII in human VSMCs, and this locus was found to harbor the quantitative trait loci affecting blood pressure. Together, these findings suggest that AngII-regulated lncRNA Alivec functions, at least in part, to mediate the AngII-induced chondrogenic transformation of VSMCs implicated in vascular dysfunction and hypertension.


Subject(s)
Angiotensin II/pharmacology , Chondrogenesis/genetics , Muscle, Smooth, Vascular/cytology , Myocytes, Smooth Muscle/metabolism , RNA, Long Noncoding/metabolism , Aggrecans/genetics , Aggrecans/metabolism , Animals , Aorta/metabolism , Blood Pressure/drug effects , Blood Pressure/genetics , Chondrogenesis/drug effects , Enhancer Elements, Genetic/genetics , Heterogeneous-Nuclear Ribonucleoprotein Group A-B/metabolism , Humans , Male , Muscle Contraction/genetics , Myocytes, Smooth Muscle/drug effects , Osteogenesis/drug effects , Osteogenesis/genetics , Phenotype , Quantitative Trait Loci/genetics , RNA, Long Noncoding/genetics , Rats, Sprague-Dawley , Receptor, Angiotensin, Type 1/genetics , Receptor, Angiotensin, Type 1/metabolism , SOX9 Transcription Factor/metabolism , Tropomyosin/metabolism , Up-Regulation/drug effects , Up-Regulation/genetics , src-Family Kinases/metabolism
20.
JCI Insight ; 6(11)2021 06 08.
Article in English | MEDLINE | ID: mdl-33945509

ABSTRACT

Long noncoding RNAs (lncRNAs) are increasingly implicated in the pathology of diabetic complications. Here, we examined the role of lncRNAs in monocyte dysfunction and inflammation associated with human type 2 diabetes mellitus (T2D). RNA sequencing analysis of CD14+ monocytes from patients with T2D versus healthy controls revealed downregulation of antiinflammatory and antiproliferative genes, along with several lncRNAs, including a potentially novel divergent lncRNA diabetes regulated antiinflammatory RNA (DRAIR) and its nearby gene CPEB2. High glucose and palmitic acid downregulated DRAIR in cultured CD14+ monocytes, whereas antiinflammatory cytokines and monocyte-to-macrophage differentiation upregulated DRAIR via KLF4 transcription factor. DRAIR overexpression increased antiinflammatory and macrophage differentiation genes but inhibited proinflammatory genes. Conversely, DRAIR knockdown attenuated antiinflammatory genes, promoted inflammatory responses, and inhibited phagocytosis. DRAIR regulated target gene expression through interaction with chromatin, as well as inhibition of the repressive epigenetic mark H3K9me2 and its corresponding methyltransferase G9a. Mouse orthologous Drair and Cpeb2 were also downregulated in peritoneal macrophages from T2D db/db mice, and Drair knockdown in nondiabetic mice enhanced proinflammatory genes in macrophages. Thus, DRAIR modulates the inflammatory phenotype of monocytes/macrophages via epigenetic mechanisms, and its downregulation in T2D may promote chronic inflammation. Augmentation of endogenous lncRNAs like DRAIR could serve as novel antiinflammatory therapies for diabetic complications.


Subject(s)
Diabetes Mellitus, Type 2/genetics , Monocytes/metabolism , RNA, Long Noncoding/genetics , RNA-Binding Proteins/genetics , Adult , Animals , Diabetes Mellitus, Type 2/metabolism , Down-Regulation , Epigenesis, Genetic , Female , Humans , Inflammation/genetics , Inflammation/metabolism , Male , Mice , RNA, Long Noncoding/metabolism , RNA-Binding Proteins/metabolism , THP-1 Cells , Young Adult
SELECTION OF CITATIONS
SEARCH DETAIL