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The cytosolic enzymes N-Acetyl Transferases 1 and 2 (NATs) transfer an acetyl group from acetyl-CoA to a xenobiotic substrate. NATs are regulated at the genetic and epigenetic levels by deacetylase enzymes such as sirtuins. The enzymatic expression of NAT1, NAT2, and SIRT1 was evaluated by flow cytometry, as well as the enzymatic activity of NATs by cell culture and HPLC analysis. Six SNPs were determined through genotyping. T2D patients (n = 29) and healthy subjects (n = 25) with a median age of 57 and 50, respectively, were recruited. An increased enzyme expression and a diminished NAT2 enzymatic activity were found in cells of T2D patients compared to the control group, while NAT1 was negatively correlated with body fat percentage and BMI. In contrast, Sirtuin inhibition increased NAT2 activity, while Sirtuin agonism decreased its activity in both groups. The analysis of NAT2 SNPs showed a higher frequency of rapid acetylation haplotypes in T2D patients compared to the control group, possibly associated as a risk factor for diabetes. The enzymatic expression of CD3+NAT2+ cells was higher in the rapid acetylators group compared to the slow acetylators group. The levels and activity of NAT1 were associated with total cholesterol and triglycerides. Meanwhile, CD3+NAT2+ cells and NAT2 activity levels were associated with HbA1c and glucose levels. The results indicate that NAT2 could be involved in metabolic processes related to the development of T2D, due to its association with glucose levels, HbA1c, and the altered SIRT-NAT axis. NAT1 may be involved with dyslipidaemias in people who are overweight or obese.
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BACKGROUND/AIM: Arylamine N-acetyltransferase 1 and 2 (NAT1 and NAT2) are drug-metabolizing enzymes that play a key role in the development of acute lymphoblastic leukemia (ALL). MATERIALS AND METHODS: This study evaluated NAT1 and NAT2 mRNA and protein expression and their enzymatic activity in peripheral blood mononuclear cells (PBMC) from patients with ALL (n=20) and healthy children (n=19) and explored the mechanisms that regulate these enzymes in ALL such as microRNAs (miR-1290, miR-26b) and SNPs. RESULTS: PBMC from patients with ALL showed a decrease in NAT1 mRNA and protein expression. In addition, NAT1 enzymatic activity was decreased in patients with ALL. There was no influence of SNP 559 C>T or 560 G>A on low NAT1 activity. The lower expression of NAT1 might be related to the loss of acetylated histone H3K14 in the NAT1 gene promoter in patients with ALL and the higher relative expression of miR-1290 in the plasma of patients with relapsed ALL compared with healthy controls. There were significantly fewer CD3+/NAT1+ double-positive cells in patients who relapsed compared with control subjects. Based on a t-distributed stochastic neighbor embedding algorithm, CD19+ cells that reappeared in patients with relapse showed low NAT1 expression. In contrast, for NAT2, there were no significant results. CONCLUSION: The expression and function of NAT1 and miR-1290 levels could be involved in modulating immune cells altered in ALL.
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Arilamina N-Acetiltransferase , MicroRNAs , Leucemia-Linfoma Linfoblástico de Células Precursoras , Criança , Humanos , Leucócitos Mononucleares/metabolismo , Projetos Piloto , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismo , MicroRNAs/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , RNA MensageiroRESUMO
Acetylation is a reversible post-translational modification (PTM) that regulates important cellular processes such as proliferation, DNA damage repair and cell cycle progress. When the balance is broken, these processes are affected and lead to carcinogenesis. Therefore, the study of acetylation has led to its proposal as a target pathway for anticancer therapies. Here, we discuss how acetylation regulates the cell cycle process, how it is modified in cancer cells and which are the key proteins in the regulation of apoptosis induction in cancer cells that can become targets to fight cancer. The inhibition of acetylation has been proposed as an emergent therapy against cancer, compounds such as 6-Penthadecyl salicylic acid, Curcumin, Garcinol and C646, among others, are currently studied because they show antitumor activity related to the inhibition of acetylation. Recently, the use of the acetylomics research tool has improved the study of acetylation as a target against tumor cells, but still the thresholds between promoting DNA instability and regulating gene expression by acetylation are not clear in many cell types.
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Histona Acetiltransferases , Neoplasias , Acetilação , Reparo do DNA , Histona Acetiltransferases/genética , Histona Acetiltransferases/metabolismo , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Processamento de Proteína Pós-TraducionalRESUMO
Since their discovery, arylamine N-acetyltransferases 1 and 2 (NAT1 and NAT2, respectively) have been associated with the metabolism of xenobiotics. NAT2 is the main factor in the therapeutic success of tuberculosis treatment due to its role in the biotransformation of isoniazid. However, researchers have started to investigate the possible participation of NAT1 and NAT2 (NATs) in carcinogenesis, although the mechanisms have not been elucidated fully. NATs enzymatic activity is essential in some types of cancer, such as breast cancer and acute lymphoblastic leukemia. Whether NAT1 and/or NAT2 participate in insulin resistance level in diabetes mellitus or in the immune system remains to be explored. Therefore, it is clear that its role in cell physiology has more implications than just metabolizing compounds.
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Arilamina N-Acetiltransferase , Acetiltransferases , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismo , Sistema Imunitário/metabolismoRESUMO
The number of acetylated proteins identified from bacteria to mammals has grown exponentially in the last ten years, and it is now accepted that acetylation is a key component in most eukaryotic signaling pathways and is as important as phosphorylation. The enzymes involved in this process are well described in mammals; acetyltransferases and deacetylases are found inside and outside the nuclear compartment and have different regulatory functions. In trypanosomatids, several of these enzymes have been described and are postulated to be novel antiparasitic targets for the rational design of drugs. In this review article, we present an update of the most important known acetylated proteins in trypanosomatids, analyzing the acetylomes available. Also, we summarize the information available regarding acetyltransferases and deacetylases in trypanosomes and their potential use as chemotherapeutic targets.
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Lisina , Processamento de Proteína Pós-Traducional , Trypanosoma , Acetilação , Acetiltransferases/metabolismo , Proteínas/metabolismo , Trypanosoma/efeitos dos fármacosRESUMO
Maple Syrup Urine Disease (MSUD) is an autosomal recessive inherited disorder that affects the activity of the branched-chainα-keto acid dehydrogenase complex (BCDK). This deficiency on BCDK complex results in the accumulation of branched-chain amino acids (BCAA) leucine, isoleucine, valine, and their corresponding α-keto acids. Epigenetic changes can negatively affect the metabolism of BCAA. These changes are catalyzed by the epigenetic regulatory enzymes, e.g., DNA methyltransferase (DNMT), histone deacetylases (HDAC), and histone acetyltransferases (HAT). However, the impacts of BCAA administration on the activity of epigenetic regulatory enzymes in the brain of MSUD patients are still unknown. In this study, we aimed to demonstrate the impact of BCAA administration on the activity of DNMT, HDAC, and HAT in the brain structures of infant rats, an animal model of MSUD. For that, we administered a BCAA pool to infant rats for 21 days. We demonstrated that BCAA administration significantly increased the DNMT and HDAC activities in the hippocampus and striatum, but not in the cerebral cortex of MSUD infant rats. A positive correlation was observed between HDAC and DNMT activities in the hippocampus and striatum of animals exposed to BCAA injections. Our results showed that the BCAA administration could modulate epigenetic regulatory enzymes, mainly DNMT and HDAC, in the brains of infant rats. Therefore, we suggest that the increase in the activity of DNMT and HDAC in the hippocampus and striatum could partially explain the neurological impairments presented in animal models of MSUD.
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Aminoácidos de Cadeia Ramificada/administração & dosagem , Córtex Cerebral/efeitos dos fármacos , Corpo Estriado/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Doença da Urina de Xarope de Bordo/metabolismo , Animais , Córtex Cerebral/metabolismo , Corpo Estriado/metabolismo , Modelos Animais de Doenças , Hipocampo/metabolismo , Masculino , Ratos , Ratos WistarRESUMO
BACKGROUND & AIMS: A causal link has recently been established between epigenetic alterations and hepatocarcinogenesis, indicating that epigenetic inhibition may have therapeutic potential. We aimed to identify and target epigenetic modifiers that show molecular alterations in hepatocellular carcinoma (HCC). METHODS: We studied the molecular-clinical correlations of epigenetic modifiers including bromodomains, histone acetyltransferases, lysine methyltransferases and lysine demethylases in HCC using The Cancer Genome Atlas (TCGA) data of 365 patients with HCC. The therapeutic potential of epigenetic inhibitors was evaluated in vitro and in vivo. RNA sequencing analysis and its correlation with expression and clinical data in the TCGA dataset were used to identify expression programs normalized by Jumonji lysine demethylase (JmjC) inhibitors. RESULTS: Genetic alterations, aberrant expression, and correlation between tumor expression and poor patient prognosis of epigenetic enzymes are common events in HCC. Epigenetic inhibitors that target bromodomain (JQ-1), lysine methyltransferases (BIX-1294 and LLY-507) and JmjC lysine demethylases (JIB-04, GSK-J4 and SD-70) reduce HCC aggressiveness. The pan-JmjC inhibitor JIB-04 had a potent antitumor effect in tumor bearing mice. HCC cells treated with JmjC inhibitors showed overlapping changes in expression programs related with inhibition of cell proliferation and induction of cell death. JmjC inhibition reverses an aggressive HCC gene expression program that is also altered in patients with HCC. Several genes downregulated by JmjC inhibitors are highly expressed in tumor vs. non-tumor parenchyma, and their high expression correlates with a poor prognosis. We identified and validated a 4-gene expression prognostic signature consisting of CENPA, KIF20A, PLK1, and NCAPG. CONCLUSIONS: The epigenetic alterations identified in HCC can be used to predict prognosis and to define a subgroup of high-risk patients that would potentially benefit from JmjC inhibitor therapy. LAY SUMMARY: In this study, we found that mutations and changes in expression of epigenetic modifiers are common events in human hepatocellular carcinoma, leading to an aggressive gene expression program and poor clinical prognosis. The transcriptional program can be reversed by pharmacological inhibition of Jumonji enzymes. This inhibition blocks hepatocellular carcinoma progression, providing a novel potential therapeutic strategy.
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Antineoplásicos/farmacologia , Carcinogênese , Carcinoma Hepatocelular , Epigênese Genética/efeitos dos fármacos , Histona Desmetilases com o Domínio Jumonji/antagonistas & inibidores , Neoplasias Hepáticas , Animais , Carcinogênese/efeitos dos fármacos , Carcinogênese/genética , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/enzimologia , Carcinoma Hepatocelular/genética , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Proteína Centromérica A/genética , Descoberta de Drogas , Humanos , Cinesinas/genética , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/enzimologia , Neoplasias Hepáticas/genética , Camundongos , Mutação , Prognóstico , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Transcriptoma , Quinase 1 Polo-LikeRESUMO
Histone deacetylases (HDACs) are a family of proteins whose main function is the removal of acetyl groups from lysine residues located on histone and non-histone substrates, which regulates gene transcription and other activities in cells. HDAC1 dysfunction has been implicated in cancer development and progression; thus, its inhibition has emerged as a new therapeutic strategy. Two additional metal binding sites (Site 1 and Site 2) in HDACs have been described that are primarily occupied by potassium ions, suggesting a possible structural role that affects HDAC activity. In this work, we explored the structural role of potassium ions in Site 1 and Site 2 and how they affect the interactions of compounds with high affinities for HDAC1 (AC1OCG0B, Chlamydocin, Dacinostat and Quisinostat) and SAHA (a pan-inhibitor) using molecular docking and molecular dynamics (MD) simulations in concert with a Molecular-Mechanics-Generalized-Born-Surface-Area (MMGBSA) approach. Four models were generated: one with a potassium ion (K+) in both sites (HDAC1k), a second with K+ only at site 1 (HDAC1ks1), a third with K+ only at site 2 (HDAC1ks2) and a fourth with no K+ (HDAC1wk). We found that the presence or absence of K+ not only impacted the structural flexibility of HDAC1, but also its molecular recognition, consistent with experimental findings. These results could therefore be useful for further structure-based drug design studies addressing new HDAC1 inhibitors.
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Histona Desacetilase 1/antagonistas & inibidores , Histona Desacetilase 1/química , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Sequência de Aminoácidos , Sítios de Ligação , Desenho de Fármacos , Inibidores de Histona Desacetilases/química , Inibidores de Histona Desacetilases/farmacologia , Concentração Inibidora 50 , Ligantes , TermodinâmicaRESUMO
Trypanosoma cruzi, the etiologic agent of Chagas disease, cycles through different life stages characterized by defined molecular traits associated with the proliferative or differentiation state. In particular, T. cruzi epimastigotes are the replicative forms that colonize the intestine of the Triatomine insect vector before entering the stationary phase that is crucial for differentiation into metacyclic trypomastigotes, which are the infective forms of mammalian hosts. The transition from proliferative exponential phase to quiescent stationary phase represents an important step that recapitulates the early molecular events of metacyclogenesis, opening new possibilities for understanding this process. In this study, we report a quantitative shotgun proteomic analysis of the T. cruzi epimastigote in the exponential and stationary growth phases. More than 3000 proteins were detected and quantified, highlighting the regulation of proteins involved in different subcellular compartments. Ribosomal proteins were upregulated in the exponential phase, supporting the higher replication rate of this growth phase. Autophagy-related proteins were upregulated in the stationary growth phase, indicating the onset of the metacyclogenesis process. Moreover, this study reports the regulation of N-terminally acetylated proteins during growth phase transitioning, adding a new layer of regulation to this process. Taken together, this study reports a proteome-wide rewiring during T. cruzi transit from the replicative exponential phase to the stationary growth phase, which is the preparatory phase for differentiation.
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Arabidopsis has 12 histone acetyltransferases grouped in four families: the GNAT/HAG, the MYST/HAM, the p300/CBP/HAC and the TAFII250/HAF families. We previously showed that ham1 and ham2 mutants accumulated higher damaged DNA after UV-B exposure than WT plants. In contrast, hag3 RNA interference transgenic plants showed less DNA damage and lower inhibition of plant growth by UV-B, and increased levels of UV-B-absorbing compounds. These results demonstrated that HAM1, HAM2, and HAG3 participate in UV-B-induced DNA damage repair and signaling. In this work, to further explore the role of histone acetylation in UV-B responses, a putative function of other acetyltransferases of the HAC and the HAF families was analyzed. Neither HAC nor HAF acetyltrasferases participate in DNA damage and repair after UV-B radiation in Arabidopsis. Despite this, haf1 mutants presented lower inhibition of leaf and root growth by UV-B, with altered expression of E2F transcription factors. On the other hand, hac1 plants showed a delay in flowering time after UV-B exposure and changes in FLC and SOC1 expression patterns. Our data indicate that HAC1 and HAF1 have crucial roles for in UV-B signaling, confirming that, directly or indirectly, both enzymes also have a role in UV-B responses.
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BACKGROUND: Acetylation and deacetylation are the most studied covalent histone modifications resulting in transcriptional regulation with histone deacetylases (HDAC) and histone acetyltransferases (HAT) as the main associated enzymes. These enzymes overexpression induces abnormal transcription of key genes that regulate important cellular functions, such as proliferation, cell cycle regulation, and apoptosis. Thus, the expression of different HATs and HDACs has been evaluated in various cancers. OBJECTIVE: To investigate HDAC1, HDAC2 and HAT1 expression in lip squamous cell carcinoma (LSCC) and actinic cheilitis (AC) and to demonstrate their correlation with DNA metyltransferases (DNMTs). MATERIAL AND METHODS: Thirty cases of lip squamous cell carcinoma (LSCC), thirty cases of actinic cheilitis (AC), and 28 cases of non-neoplastic epithelium as control were selected for immunohistochemical investigation. RESULTS: Nuclear HDAC2 immunopositivity was significantly higher in AC (75.07% ± 29.70) when compared with LSCC (51.06% ± 39.02). HDAC1 and HAT1 nuclear immunostaining were higher in AC, with no statistical significance. When comparing data with our previous study, we found a positive correlation between HDAC1 X DNMT1/DNMT3b, HDAC2 X DNMT3b, and HAT1 X DNMT1/DNMT3b for certain studied groups. CONCLUSION: This study showed higher levels of nuclear HDAC2 immunopositivity in AC, possibly indicating that this enzyme plays a key role in lip photocarcinogenesis early stages.
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Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/enzimologia , Queilite/enzimologia , Histona Acetiltransferases/metabolismo , Histona Desacetilase 1/metabolismo , Histona Desacetilase 2/metabolismo , Neoplasias Labiais/enzimologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Criança , Pré-Escolar , Metilases de Modificação do DNA/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Las infecciones por Klebsiella pneumoniae, constituyen un problema creciente en los centros hospitalarios. El objetivo de la presente investigación fue evaluar la resistencia a los aminoglucósidos, así como la presencia de genes que codifican enzimas modificadoras de aminoglucósidos (EMA) en aislados intrahospitalarios de Klebsiella pneumoniae. Se analizaron 56 cepas provenientes de pacientes con diagnóstico de infección intrahospitalaria del Hospital Universitario Antonio Patricio de Alcalá, durante el periodo enero-septiembre de 2008. Se determinó la susceptibilidad antimicrobiana mediante los métodos de difusión y dilución en agar, siguiendo los lineamientos del Instituto de Estándares Clínicos y de Laboratorio. Se empleó la técnica de la reacción en cadena de la polimerasa (PCR) para detectar los genes que codifican EMA. Se encontró resistencia a gentamicina y tobramicina en el 33,9% y 35,7%, respectivamente. Los fenotipos de resistencia a aminoglucósidos más frecuentes fueron I (ANGMKTob) y II (GMKTob). Se identificaron los genes aadA (21,4%), aac(3)-IIa (16,1%), aadB (14,3%), aac (6`)-Ib (3,6%) y aph (3`)-Ia (1,8%). En 10 cepas se observó la presencia de más de un gen y en 13 cepas se correlacionó el fenotipo con los genes encontrados. La resistencia a los aminoglucósidos en los aislados evaluados se debe, principalmente, a enzimas de tipo acetiltransferasas.
Klebsiella pneumoniae infection is a growing problem in hospitals. The objective of this study was to evaluate resistance to aminoglycosides and detection of genes encoding for aminoglycoside modifying enzymes (AME) in hospital isolates of K. pneumoniae. Fifty-six isolates from patients with diagnosis of nosocomial infection at the University Hospital Antonio Patricio de Alcala, during the period January to September 2008 were included for study. Antimicrobial susceptibility was determined by the methods of diffusion and agar dilution, following the Institute for Clinical and Laboratory Standards Guidelines. Genes encoding AME were determined by the polymerase chain reaction procedure. Resistance results for Gentamycin were 33.9% and for Tobramycin 35.7%. Aminoglycoside resistance phenotypes most frequently identified were I (ANGMKTob) and II (GMKTob). The genes involved were aadA (21.4%), aac(3)-IIa (16.1%), aadB (14.3%), aac (6`)-Ib (3.6%) y aph (3`)-Ia (1.8%) For 10 of the isolates studied more than one gene was identified. In 13 isolates the phenotype corresponded to the genes found. Aminoglycoside resistance in the isolates studied is mainly due to the presence of acetyltransferase enzymes.
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Histone acetylation is regulated by histone acetyltransferases and deacetylases. In Arabidopsis, there are 12 histone acetyltransferases and 18 deacetylases. Histone acetyltransferases are organized in four families: the GNAT/HAG, the MYST, the p300/CBP and the TAFII250 families. Previously, we demonstrated that Arabidopsis mutants in the two members of the MYST acetyltransferase family show increased DNA damage after UV-B irradiation. To investigate further the role of other histone acetyltransferases in UV-B responses, a putative role for enzymes of the GNAT family, HAG1, HAG2 and HAG3, was analyzed. HAG transcripts are not UV-B regulated; however, hag3 RNA interference (RNAi) transgenic plants show a lower inhibition of leaf and root growth by UV-B, higher levels of UV-B-absorbing compounds and less UV-B-induced DNA damage than Wassilewskija (Ws) plants, while hag1 RNAi transgenic plants and hag2 mutants do not show significant differences from wild-type plants. Transcripts for UV-B-regulated genes are highly expressed under control conditions in the absence of UV-B in hag3 RNAi transgenic plants, suggesting that the higher UV-B tolerance may be due to increased levels of proteins that participate in UV-B responses. Together, our data provide evidence that HAG3, directly or indirectly, participates in UV-B-induced DNA damage repair and signaling.