RESUMO
Metastasis is the primary cause of cancer-related deaths, and colorectal cancer (CRC) liver metastasis is a major poor prognostic factor in CRC. NAT1 (N-acetyltransferase 1) plays a crucial role in the invasive and metastatic processes of colorectal cancer. The role and molecular mechanism of NAT1 on tumor cells were verified by establishing a cell model of overexpression and knockdown of NAT1, and further verified by establishing a liver metastasis model of colorectal cancer for animal experiments. In vivo and in vitro experiments have demonstrated that overexpression of NAT1 reduces the ability of metastasis and invasion of colorectal cancer cells. NAT1 overexpression inhibits the PI3K/AKT/mTOR signaling pathway, thereby suppressing the EMT (epithelial-mesenchymal transition) process and glycolytic ability of tumor cells. Additionally, decreased glycolytic ability results in reduced VEGF (Vascular endothelial growth factor) expression in colorectal cancer cells. The decreased VEGF expression leads to decreased angiogenesis and vascular permeability in liver metastases, ultimately reducing the occurrence of liver metastasis. Our findings highlight that overexpression of NAT1 significantly inhibits the PI3K/AKT/mTOR signaling pathway, thereby suppressing EMT, glycolytic ability, and VEGF expression in colorectal cancer cells, collectively preventing the development of liver metastasis.
Assuntos
Arilamina N-Acetiltransferase , Neoplasias Colorretais , Transição Epitelial-Mesenquimal , Glicólise , Neoplasias Hepáticas , Transdução de Sinais , Neoplasias Colorretais/patologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Transição Epitelial-Mesenquimal/genética , Humanos , Neoplasias Hepáticas/secundário , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Animais , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismo , Linhagem Celular Tumoral , Camundongos , Serina-Treonina Quinases TOR/metabolismo , Isoenzimas/metabolismo , Isoenzimas/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosfatidilinositol 3-Quinases/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Regulação Neoplásica da Expressão Gênica , Camundongos NusRESUMO
In this study, we investigated the role of LINC00520 in colorectal cancer (CRC) progression. We analyzed LINC00520 expression in 15 pairs of CRC tissues and adjacent tissues using qRT-PCR, revealing significantly elevated levels in CRC tissues and cell lines. Lentivirus-mediated up/down-regulation of LINC00520 in CRC cell lines demonstrated that increased LINC00520 expression enhanced cell invasiveness, as confirmed by transwell and wound healing assays. Bioinformatics analysis identified a regulatory axis involving LINC00520, microRNA-195-3p, and NAT2. Luciferase assays confirmed direct binding between LINC00520 and microRNA-195-3p, as well as microRNA-195-3p and NAT2. Overexpression of NAT2 reversed the inhibitory effects on invasion and migration induced by LINC00520 silencing. This suggests that LINC00520, highly expressed in CRC tissues, may modulate tumor biological functions through the microRNA-195-3p/NAT2 axis. Our findings provide insights into the mechanism underlying CRC progression, highlighting the potential of LINC00520 as a therapeutic target.
Assuntos
Arilamina N-Acetiltransferase , Movimento Celular , Neoplasias Colorretais , Progressão da Doença , Regulação Neoplásica da Expressão Gênica , MicroRNAs , RNA Longo não Codificante , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Neoplasias Colorretais/metabolismo , Linhagem Celular Tumoral , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismo , Movimento Celular/genética , Invasividade Neoplásica/genética , Proliferação de Células/genéticaRESUMO
Microbial NAT enzymes, which employ acyl-CoA to acylate aromatic amines and hydrazines, have been well-studied for their role in xenobiotic metabolism. Some homologues have also been linked to secondary metabolism, but this function of NAT enzymes is not as well-known. For this comparative study, we surveyed sequenced microbial genomes to update the list of formally annotated NAT genes, adding over 4000 new sequences (mainly bacterial, but also archaeal, fungal and protist) and portraying a broad but not universal distribution of NATs in the microbiocosmos. Localization of NAT sequences within microbial gene clusters was not a rare finding, and this association was evident across all main types of biosynthetic gene clusters (BGCs) implicated in secondary metabolism. Interrogation of the MIBiG database for experimentally characterized clusters with NAT genes further supports that secondary metabolism must be a major function for microbial NAT enzymes and should not be overlooked by researchers in the field. We also show that NAT sequences can be associated with bacterial plasmids potentially involved in horizontal gene transfer. Combined, our computational predictions and MIBiG literature findings reveal the extraordinary functional diversification of microbial NAT genes, prompting further research into their role in predicted BGCs with as yet uncharacterized function.
Assuntos
Bactérias , Família Multigênica , Metabolismo Secundário , Metabolismo Secundário/genética , Bactérias/genética , Bactérias/metabolismo , Archaea/genética , Archaea/metabolismo , Filogenia , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismo , Fungos/genética , Genômica/métodos , Transferência Genética HorizontalRESUMO
Waterpipe smoking is increasingly popular and understanding how chemicals found in hookah smoke may be harmful to human bronchial epithelial cells is of great importance. 4,4'-Oxydianiline (ODA), is an aromatic amine which is present at comparatively high levels in hookah smoke. The metabolism and the subsequent toxicity of ODA in human bronchial epithelial cells remains unknown. Given that ODA is an aromatic amine, we hypothesized that ODA is N-acetylated and induces DNA damage following exposure to immortalized human bronchial epithelial cells (BEP2D cells). We measured the N-acetylation of ODA to mono-acetyl-ODA and the N-acetylation of mono-acetyl-ODA to diacetyl-ODA by BEP2D cells following separation and quantitation by high performance liquid chromatography. For ODA, the apparent KM in cells was 12.4 ± 3.7⯵M with a Vmax of 0.69 ± 0.03 nmol/min/106 cells, while for mono-acetyl-ODA, the apparent KM was 111.2 ± 48.3⯵M with a Vmax of 17.8 ± 5.7 nmol/min/106 cells ODA exposure for 24â¯h resulted in DNA damage to BEP2D cells following concentrations as low as 0.1⯵M as measured by yH2Ax protein expression These results demonstrate that ODA, the most prevalent aromatic amine identified in hookah smoke, is N-acetylated and induces DNA damage in human bronchial epithelial cells.
Assuntos
Arilamina N-Acetiltransferase , Brônquios , Dano ao DNA , Células Epiteliais , Humanos , Brônquios/efeitos dos fármacos , Brônquios/citologia , Brônquios/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismo , Acetilação , Linhagem Celular , Fumaça/efeitos adversos , IsoenzimasRESUMO
Hydrogen sulfide (H2S), a critical gas signaling molecule, and N-acetyltransferase 2 (NAT2), a key enzyme in drug metabolism, are both known active biomarkers for liver function. However, the interactions and effects of H2S and NAT2 in living cells or lesion sites remain unknown due to the lack of imaging tools to achieve simultaneous detection of these two substances, making it challenging to implement real-time imaging and precise tracking. Herein, we report an activity-based two-photon fluorescent probe, TPSP-1, for the cascade detection of H2S and NAT2 in living liver cells. Continuous conversion from TPSP-1 to TPSP-3 was achieved in liver cells and tissues. Significantly, leveraging the outstanding optical properties of this two-photon fluorescent probe, TPSP-1, has been effectively used to identify pathological tissue samples directly from clinical liver cancer patients. This work provides us with this novel sensing and two-photon imaging probe, which can be used as a powerful tool to study the physiological functions of H2S and NAT2 and will help facilitate rapid and accurate diagnosis and therapeutic evaluation of hepatocellular carcinoma.
Assuntos
Arilamina N-Acetiltransferase , Carcinoma Hepatocelular , Corantes Fluorescentes , Sulfeto de Hidrogênio , Neoplasias Hepáticas , Fótons , Sulfeto de Hidrogênio/análise , Sulfeto de Hidrogênio/metabolismo , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Humanos , Arilamina N-Acetiltransferase/metabolismo , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Animais , Camundongos , Células Hep G2 , Imagem ÓpticaRESUMO
This work shows the utilization of a physiologically based biopharmaceutics model (PBBM) to mechanistically explain the impact of diverse food types on the pharmacokinetics (PK) of isoniazid (INH) and acetyl-isoniazid (Ac-INH). The model was established and validated using published PK profiles for INH along with a combination of measured and predicted values for the physico-chemical and biopharmaceutical propertied of INH and Ac-INH. A dedicated ontogeny model was developed for N-acetyltransferase 2 (NAT2) in human integrating Michaelis Menten parameters for this enzyme in the physiologically based pharmacokinetic (PBPK) model tissues and in the gut, to explain the pre-systemic and systemic metabolism of INH across different acetylator types. Additionally, a novel equation was proposed to calculate the luminal drug degradation related to the presence of reducing sugars, using individual sugar molar concentrations in the meal. By incorporating luminal degradation into the model, adjusting bile salt concentrations and gastric emptying according to food type and quantity, the PBBM was able to accurately predict the negative effect of carbohydrate-rich diets on the PK of INH.
Assuntos
Antituberculosos , Interações Alimento-Droga , Isoniazida , Modelos Biológicos , Isoniazida/farmacocinética , Isoniazida/administração & dosagem , Humanos , Antituberculosos/farmacocinética , Antituberculosos/administração & dosagem , Arilamina N-Acetiltransferase/metabolismo , Biofarmácia/métodosRESUMO
N-acetyltransferase 2 (NAT2) genetic polymorphisms might alter isoniazid metabolism leading to toxicity. We reviewed the impact of NAT2 genotype status on the pharmacokinetics, efficacy, and safety of isoniazid, a treatment for tuberculosis (TB). A systematic search for research articles published in Scopus, PubMed, and Embase until August 31, 2023, was conducted without filters or limits on the following search terms and Boolean operators: "isoniazid" AND "NAT2." Studies were selected if NAT2 phenotypes with pharmacokinetics or efficacy or safety of isoniazid in patients with TB were reported. Patient characteristics, NAT2 status, isoniazid pharmacokinetic parameters, early treatment failure, and the prevalence of drug-induced liver injury were extracted. If the data were given as a median, these values were standardized to the mean. Forty-one pharmacokinetics and 53 safety studies were included, but only one efficacy study was identified. The average maximum concentrations of isoniazid were expressed as supratherapeutic concentrations in adults (7.16 ± 4.85 µg/mL) and children (6.43 ± 3.87 µg/mL) in slow acetylators. The mean prevalence of drug-induced liver injury was 36.23 ± 19.84 in slow acetylators, which was significantly different from the intermediate (19.49 ± 18.20) and rapid (20.47 ± 20.68) acetylators. Subgroup analysis by continent showed that the highest mean drug-induced liver injury prevalence was in Asian slow acetylators (42.83 ± 27.61). The incidence of early treatment failure was decreased by genotype-guided isoniazid dosing in one study. Traditional weight-based dosing of isoniazid in most children and adults yielded therapeutic isoniazid levels (except for slow acetylators). Drug-induced liver injury was more commonly observed in slow acetylators. Genotype-guided dosing may prevent early treatment failure.
Assuntos
Antituberculosos , Arilamina N-Acetiltransferase , Doença Hepática Induzida por Substâncias e Drogas , Isoniazida , Tuberculose , Adulto , Criança , Humanos , Antituberculosos/efeitos adversos , Antituberculosos/farmacocinética , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/genética , Genótipo , Isoniazida/efeitos adversos , Isoniazida/farmacocinética , Polimorfismo Genético , Tuberculose/tratamento farmacológico , Tuberculose/genéticaRESUMO
Anti-tuberculosis (AT) medications, including isoniazid (INH), can cause drug-induced liver injury (DILI), but the underlying mechanism remains unclear. In this study, we aimed to identify genetic factors that may increase the susceptibility of individuals to AT-DILI and to examine genetic interactions that may lead to isoniazid (INH)-induced hepatotoxicity. We performed a targeted sequencing analysis of 380 pharmacogenes in a discovery cohort of 112 patients (35 AT-DILI patients and 77 controls) receiving AT treatment for active tuberculosis. Pharmacogenome-wide association analysis was also conducted using 1048 population controls (Korea1K). NAT2 and ATP7B genotypes were analyzed in a replication cohort of 165 patients (37 AT-DILI patients and 128 controls) to validate the effects of both risk genotypes. NAT2 ultraslow acetylators (UAs) were found to have a greater risk of AT-DILI than other genotypes (odds ratio [OR] 5.6 [95% confidence interval; 2.5-13.2], P = 7.2 × 10-6). The presence of ATP7B gene 832R/R homozygosity (rs1061472) was found to co-occur with NAT2 UA in AT-DILI patients (P = 0.017) and to amplify the risk in NAT2 UA (OR 32.5 [4.5-1423], P = 7.5 × 10-6). In vitro experiments using human liver-derived cell lines (HepG2 and SNU387 cells) revealed toxic synergism between INH and Cu, which were strongly augmented in cells with defective NAT2 and ATP7B activity, leading to increased mitochondrial reactive oxygen species generation, mitochondrial dysfunction, DNA damage, and apoptosis. These findings link the co-occurrence of ATP7B and NAT2 genotypes to the risk of INH-induced hepatotoxicity, providing novel mechanistic insight into individual AT-DILI susceptibility. Yoon et al. showed that individuals who carry NAT2 UAs and ATP7B 832R/R genotypes are at increased risk of developing isoniazid hepatotoxicity, primarily due to the increased synergistic toxicity between isoniazid and copper, which exacerbates mitochondrial dysfunction-related apoptosis.
Assuntos
Arilamina N-Acetiltransferase , Doença Hepática Induzida por Substâncias e Drogas , Doenças Mitocondriais , Tuberculose , Humanos , Antituberculosos/efeitos adversos , Antituberculosos/toxicidade , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/genética , Cobre/toxicidade , Genótipo , Isoniazida/toxicidade , Tuberculose/tratamento farmacológico , Tuberculose/genéticaRESUMO
In humans, there are two arylamine N-acetyltransferase genes that encode functional enzymes (NAT1 and NAT2) as well as one pseudogene, all of which are located together on chromosome 8. Although they were first identified by their role in the acetylation of drugs and other xenobiotics, recent studies have shown strong associations for both enzymes in a variety of diseases, including cancer, cardiovascular disease, and diabetes. There is growing evidence that this association may be causal. Consistently, NAT1 and NAT2 are shown to be required for healthy mitochondria. This review discusses the current literature on the role of both NAT1 and NAT2 in mitochondrial bioenergetics. It will attempt to relate our understanding of the evolution of the two genes with biologic function and then present evidence that several major metabolic diseases are influenced by NAT1 and NAT2. Finally, it will discuss current and future approaches to inhibit or enhance NAT1 and NAT2 activity/expression using small-molecule drugs. SIGNIFICANCE STATEMENT: The arylamine N-acetyltransferases (NATs) NAT1 and NAT2 share common features in their associations with mitochondrial bioenergetics. This review discusses mitochondrial function as it relates to health and disease, and the importance of NAT in mitochondrial function and dysfunction. It also compares NAT1 and NAT2 to highlight their functional similarities and differences. Both NAT1 and NAT2 are potential drug targets for diseases where mitochondrial dysfunction is a hallmark of onset and progression.
Assuntos
Arilamina N-Acetiltransferase , Doenças Metabólicas , Doenças Mitocondriais , Humanos , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismo , Acetiltransferases/genética , Acetiltransferases/metabolismo , Especificidade por Substrato , Doenças Metabólicas/tratamento farmacológico , Doenças Mitocondriais/tratamento farmacológicoRESUMO
BACKGROUND: Tuberculosis (TB) treatment-related adverse drug reactions (TB-ADRs) can negatively affect adherence and treatment success rates. METHODS: We developed prediction models for TB-ADRs, considering participants with drug-susceptible pulmonary TB who initiated standard TB therapy. TB-ADRs were determined by the physician attending the participant, assessing causality to TB drugs, the affected organ system, and grade. Potential baseline predictors of TB-ADR included concomitant medication (CM) use, human immunodeficiency virus (HIV) status, glycated hemoglobin (HbA1c), age, body mass index (BMI), sex, substance use, and TB drug metabolism variables (NAT2 acetylator profiles). The models were developed through bootstrapped backward selection. Cox regression was used to evaluate TB-ADR risk. RESULTS: There were 156 TB-ADRs among 102 of the 945 (11%) participants included. Most TB-ADRs were hepatic (n = 82 [53%]), of moderate severity (grade 2; n = 121 [78%]), and occurred in NAT2 slow acetylators (n = 62 [61%]). The main prediction model included CM use, HbA1c, alcohol use, HIV seropositivity, BMI, and age, with robust performance (c-statistic = 0.79 [95% confidence interval {CI}, .74-.83) and fit (optimism-corrected slope and intercept of -0.09 and 0.94, respectively). An alternative model replacing BMI with NAT2 had similar performance. HIV seropositivity (hazard ratio [HR], 2.68 [95% CI, 1.75-4.09]) and CM use (HR, 5.26 [95% CI, 2.63-10.52]) increased TB-ADR risk. CONCLUSIONS: The models, with clinical variables and with NAT2, were highly predictive of TB-ADRs.
Assuntos
Arilamina N-Acetiltransferase , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Soropositividade para HIV , Tuberculose Pulmonar , Humanos , Antituberculosos/efeitos adversos , Brasil/epidemiologia , Hemoglobinas Glicadas , Soropositividade para HIV/tratamento farmacológico , Tuberculose Pulmonar/tratamento farmacológico , Arilamina N-Acetiltransferase/metabolismoRESUMO
Tobacco smoking is the most important risk factor for bladder cancer. Previous studies have identified the N-acetyltransferase (NAT2) gene in association with bladder cancer risk. The NAT2 gene encodes an enzyme that metabolizes aromatic amines, carcinogens commonly found in tobacco smoke. In our study, we evaluated potential interactions of tobacco smoking with NAT2 genotypes and polygenic risk score (PRS) for bladder cancer, using data from the UK Biobank, a large prospective cohort study. We used Cox proportional hazards models to measure the strength of the association. The PRS was derived using genetic risk variants identified by genome-wide association studies for bladder cancer. With an average of 10.1 years of follow-up of 390 678 eligible participants of European descent, 769 incident bladder cancer cases were identified. Current smokers with a PRS in the highest tertile had a higher risk of developing bladder cancer (HR: 6.45, 95% CI: 4.51-9.24) than current smokers with a PRS in the lowest tertile (HR: 2.41, 95% CI: 1.52-3.84; P for additive interaction = <.001). A similar interaction was found for genetically predicted metabolizing NAT2 phenotype and tobacco smoking where current smokers with the slow NAT2 phenotype had an increased risk of developing bladder cancer (HR: 5.70, 95% CI: 2.64-12.30) than current smokers with the fast NAT2 phenotype (HR: 3.61, 95% CI: 1.14-11.37; P for additive interaction = .100). Our study provides support for considering both genetic and lifestyle risk factors in developing prevention measures for bladder cancer.
Assuntos
Arilamina N-Acetiltransferase , Neoplasias da Bexiga Urinária , Humanos , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismo , Estudos de Casos e Controles , Estudo de Associação Genômica Ampla , Genótipo , Estudos Prospectivos , Fatores de Risco , Fumar/efeitos adversos , Fumar/genética , Fumar Tabaco/efeitos adversos , Fumar Tabaco/genética , Neoplasias da Bexiga Urinária/etiologia , Neoplasias da Bexiga Urinária/genéticaRESUMO
OBJECTIVES: Head and neck cancer (HNC) is one of the most common cancers. Most exogenous HNC is head and neck squamous cell carcinomas. Scientists are striving to develop diagnostic tests that will allow the prognosis of HNC. The aim of the study was to determine the risk of HNC. The research concerned changes caused by polymorphisms in genes encoding proteins responsible for the metabolism of xenobiotics. MATERIAL AND METHODS: In group of 280 patients with HNC, the occurrence of polymorphic variants in NAT1(rs72554606), NAT2(rs1799930), CYP1A(rs1799814), CYP2D(rs3892097) were studied with TaqMan technique. The control group consisted of 260 cancer free people. The TNM scale was analyzed. Gene interactions of genotyped polymorphisms were investigated. The effects of smoking and alcohol consumption on HNC were assessed. RESULTS: The results indicated an increased risk of HNC in NAT1 polymorphisms in the GC genotype (OR = 1.772, 95% CI: 1.184-2.651, p = 0.005) and NAT2 polymorphism in the GA genotype (OR = 1.506, 95% CI: 1.023-2.216, p = 0.037). The protective phenomenon in the CYP1A polymorphism the GT genotype (OR = 0.587, 95% CI: 0.381-0.903, p = 0.015) and the TT genotype (OR = 0.268, 95% CI: 0.159-0.452, p = 0.001). The coexistence of GA-GC polymorphisms (OR = 2.687, 95% CI: 1.387-5.205, p = 0.003) in NAT2-NAT1 genes increases the risk of HNC. Risk-reducing effect in the polymorphism GG-GT (OR = 0.340, 95% CI: 0.149-0.800, p = 0.011), GG-TT (OR = 0.077, 95% CI: 0.028-0.215, p < 0.0001), GA-TT (OR = 0.250, 95% CI: 0.100-0.622, p = 0.002), AA-GT (OR = 0.276, 95% CI: 0.112-0.676, p = 0.002) in NAT2-CYP1A genes. In the CYP2D-CYP1A genes in the polymorphisms CT-CC (OR = 0.338, 95% CI: 0.132-0.870, p = 0.020), TT-GG (OR = 0.100, 95% CI: 0.027-0.359, p = 0.001), TT-GC (OR = 0.190, 95% CI: 0.072-0.502, p = 0.0004), TT-CC (OR = 0.305, 95% CI: 0.107-0.868, p = 0.024). Correlation was noted between cigarette smoking and HNC (OR = 7.297, 95% CI: 4.989-10.674, p < 0.0001) and consuming alcohol (OR = 1.572, 95% CI: 1.003-2.464, p = 0.047). CONCLUSIONS: The CYP1A polymorphism shows a protective association with HNC. On the other hand, NAT2, NAT1 polymorphism influence the susceptibility to developing HNC. The coexistence of the NAT2-NAT1 genotypes increases the risk of HNC. In contrast, NAT1-CYP1A and CYP1A-CYP2D reduce this risk. Smoking and alcohol consumption increase the incidence of HNC. Int J Occup Med Environ Health. 2023;36(6):812-24.
Assuntos
Arilamina N-Acetiltransferase , Neoplasias de Cabeça e Pescoço , Humanos , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismo , Incidência , Polônia/epidemiologia , Fumar/epidemiologia , Fatores de Risco , Polimorfismo Genético , Genótipo , Neoplasias de Cabeça e Pescoço/epidemiologia , Neoplasias de Cabeça e Pescoço/genética , Sistema Enzimático do Citocromo P-450/genética , Predisposição Genética para Doença , Estudos de Casos e ControlesRESUMO
Pregnancy can increase the risk of latent tuberculosis infection (LTBI) progression to tuberculosis (TB) disease. Isoniazid (INH) is the preferred preventative treatment for LTBI in pregnancy. INH is mainly cleared by N-acetyltransferase 2 (NAT2) but the pharmacokinetics (PK) of INH in different NAT2 phenotypes during pregnancy is not well characterized. To address this knowledge gap, we used physiologically based pharmacokinetic (PBPK) modeling to evaluate NAT2 phenotype-specific effects of pregnancy on INH disposition. A whole-body PBPK model for INH was developed and verified for non-pregnant NAT2 fast (FA), intermediate (IA), and slow (SA) acetylators. Model predictive performance was assessed using a drug-specific model acceptance criterion for mean plasma area under the curve (AUC) and peak plasma concentration (Cmax ), and the absolute average fold error (AAFE) for individual plasma concentrations. The verified model was extended to simulate INH disposition during pregnancy in NAT2 SA, IA, and FA populations. A sensitivity analysis was conducted using the verified PBPK model and known changes in INH disposition during pregnancy to determine whether NAT2 activity changes during pregnancy or other INH clearance pathways are altered. This analysis suggested that NAT2 activity is unchanged while other INH clearance pathways increase by ~80% during pregnancy. The model was applied to explore the effect of pregnancy on INH disposition in two ethnic populations with different NAT2 phenotype distributions and with high TB burden. Our PBPK model can be used to predict INH disposition during pregnancy in diverse populations and expanded to other drugs cleared by NAT2 during pregnancy.
Assuntos
Arilamina N-Acetiltransferase , Tuberculose , Humanos , Gravidez , Feminino , Isoniazida , Antituberculosos/farmacocinética , Genótipo , Tuberculose/tratamento farmacológico , Fenótipo , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismoRESUMO
Heterocyclic amines (HCAs) are mutagenic compounds found in cooked meat. Recent epidemiological studies reported significant associations between dietary HCA exposure and insulin resistance and type II diabetes, and we recently reported that HCAs induce insulin resistance and glucose production in human hepatocytes. It is well known that HCAs require hepatic bioactivation by cytochrome P450 1A2 (CYP1A2) and N-acetyltransferase 2 (NAT2). NAT2 expresses a well-defined genetic polymorphism in humans that, depending on the combination of NAT2 alleles, correlates to rapid, intermediate, or slow acetylator phenotype that exhibits differential metabolism of aromatic amines and HCAs. No previous studies have examined the role of NAT2 genetic polymorphism in the context of HCA-mediated induction of glucose production. In the present study, we assessed the effect of three HCAs commonly found in cooked meat (2-amino-3,4-dimethylimidazo[4,5-f]quinoline [MeIQ], 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline [MeIQx], and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine [PhIP]) on glucose production in cryopreserved human hepatocytes with slow, intermediate, or rapid NAT2 acetylator phenotype. HCA treatment did not affect glucose production in slow NAT2 acetylator hepatocytes, while a slight increase in glucose production was observed in intermediate NAT2 acetylators treated with MeIQ or MeIQx. However, significant increases in glucose production were observed in rapid NAT2 acetylators following each HCA. The current findings suggest that individuals who are rapid NAT2 acetylators may be at a greater risk of developing hyperglycemia and insulin resistance following dietary exposure to HCAs.
Assuntos
Aminas , Arilamina N-Acetiltransferase , Diabetes Mellitus Tipo 2 , Compostos Heterocíclicos , Resistência à Insulina , Humanos , Acetiltransferases/genética , Acetiltransferases/metabolismo , Aminas/toxicidade , Aminas/metabolismo , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Glucose/metabolismo , Hepatócitos/metabolismo , Compostos Heterocíclicos/metabolismo , Polimorfismo GenéticoRESUMO
Unfavorable treatment outcomes for tuberculosis (TB) treatment might result from altered plasma exposure to antitubercular drugs in TB patients. The present study investigated the distribution of the N-Acetyltransferase 2 (NAT2) genotype, isoniazid acetylation status, genotype-phenotype concordance of NAT2, and isoniazid plasma exposure among Ethiopian tuberculosis patients. Blood samples were collected from newly diagnosed TB patients receiving a fixed dose combination of first-line antitubercular drugs daily. Genotyping of NAT2 was done using TaqMan drug metabolism assay. Isoniazid and its metabolite concentration were determined using validated liquid chromatography-tandem mass spectrometry (LC-MS/MS). A total of 120 patients (63 male and 57 female) were enrolled in this study. The mean daily dose of isoniazid was 4.71 mg/kg. The frequency of slow, intermediate, and fast NAT2 acetylators genotypes were 74.2%, 22.4%, and 3.3% respectively. The overall median isoniazid maximum plasma concentration (Cmax) was 4.77 µg/mL and the AUC0-7 h was 11.21 µg.h/mL. The median Cmax in slow, intermediate, and fast acetylators were 5.65, 3.44, and 2.47 µg/mL, respectively. The median AUC0-7 h hour in slow, intermediate, and fast acetylators were 13.1, 6.086, and 3.73 mgâ¢h/L, respectively. The majority (87.5%) of the study participants achieved isoniazid Cmax of above 3 µg/mL, which is considered a lower limit for a favorable treatment outcome. There is 85% concordance between the NAT2 genotype and acetylation phenotypes. NAT2 genotype, female sex, and dose were independent predictors of Cmax and AUC0-7 h (p < 0.001). Our finding revealed that there is a high frequency of slow NAT2 genotypes. The plasma Cmax of isoniazid was higher in the female and slow acetylators genotype group. The overall target plasma isoniazid concentrations in Ethiopian tuberculosis patients were achieved in the majority of the patients. Therefore, it is important to monitor adverse drug reactions and the use of a higher dose of isoniazid should be closely monitored.
Assuntos
Arilamina N-Acetiltransferase , Tuberculose , Masculino , Feminino , Humanos , Isoniazida/efeitos adversos , Cromatografia Líquida , Acetilação , Espectrometria de Massas em Tandem , Tuberculose/tratamento farmacológico , Tuberculose/genética , Antituberculosos/efeitos adversos , Genótipo , Acetiltransferases/metabolismo , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismoRESUMO
A novel haplotype in N -acetyltransferase 2 ( NAT2 ) composed of seven non-coding variants (rs1495741, rs4921913, rs4921914, rs4921915, rs146812806, rs35246381, and rs35570672) has been linked to dyslipidemia by multiple, independent genome-wide association studies. The haplotype is located approximately 14 kb downstream of NAT2-coding region (ch8:18,272,377-18,272,881; GRCh38/hg38) and represents a non-coding, intergenic haplotype. Interestingly, the same dyslipidemia NAT2 haplotype is also linked to urinary bladder cancer risk. Dyslipidemia risk alleles are associated with rapid acetylator phenotype, whereas bladder cancer risk alleles are associated with slow acetylator, suggesting that the level of systemic NAT2 activity modifies the risk of these pathologies. We speculate that rs1495741 (and its associated haplotype) belongs to a distal regulatory element of human NAT2 gene (e.g., enhancer or silencer), and the genetic variation at the newly discovered haplotype results in a differential level of NAT2 gene expression. Understanding how this NAT2 haplotype contributes to not only urinary bladder cancer but also to dyslipidemia will ultimately help devise strategies to identify and protect susceptible individuals.
Assuntos
Arilamina N-Acetiltransferase , Dislipidemias , Neoplasias da Bexiga Urinária , Humanos , Acetilação , Acetiltransferases/genética , Acetiltransferases/metabolismo , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismo , Estudo de Associação Genômica Ampla , Genótipo , Haplótipos , Neoplasias da Bexiga Urinária/genética , Dislipidemias/genéticaRESUMO
There are two human arylamine N-acetyltransferases (NAT1 and NAT2) that have evolved separately and differ in their substrate specificity and tissue localization. In addition to its acetyltransferase activity, NAT1 can hydrolyze acetyl coenzyme A to coenzyme A in the presence of folate. Here, we show that NAT1 is rapidly inactivated at temperatures above 39 °C whereas NAT2 is more stable. NAT1 acetyltransferase activity is also rapidly lost in whole cells at a rate similar to that of recombinant protein, suggesting it is not protected by intracellular chaperones. By contrast, the hydrolase activity of NAT1 is resistant to heat-induced inactivation, in part because folate stabilizes the protein. Heat generated by mitochondria following the dissipation of the inner membrane potential was sufficient to inactivate NAT1 in whole cells. Within the physiological range of core body temperatures (36.5-37.5 °C), NAT1 acetyltransferase activity decreased by 30% while hydrolase activity increased by >50%. This study demonstrates the thermal regulation of NAT1, but not NAT2, and suggests that NAT1 may switch between an acetyltransferase and a hydrolase within a narrow temperature range in the presence of folate.
Assuntos
Arilamina N-Acetiltransferase , Humanos , Arilamina N-Acetiltransferase/metabolismo , Temperatura , Acetil-CoA Hidrolase , Acetiltransferases/metabolismo , Ácido FólicoRESUMO
4,4'-Methylenebis(2-chloroaniline) or MOCA is an aromatic amine used primarily in polyurethane and rubber industry. MOCA has been linked to hepatomas in animal studies while limited epidemiologic studies reported the association of exposure to MOCA and urinary bladder and breast cancer. We investigated MOCA-induced genotoxicity and oxidative stress in DNA repair-deficient Chinese hamster ovary (CHO) cells stably transfected with human metabolizing enzymes CYP1A2 and N-acetyltransferase 2 (NAT2) variants as well as in rapid, intermediate, and slow NAT2 acetylator cryopreserved human hepatocytes. N-acetylation of MOCA was highest in UV5/1A2/NAT2*4 followed by UV5/1A2/NAT2*7B and UV5/1A2/NAT2*5B CHO cells. Human hepatocytes showed a NAT2 genotype-dependent response with highest N-acetylation in rapid acetylators followed by intermediate and slow acetylators. MOCA induced higher levels of mutagenesis and DNA damage in UV5/1A2/NAT2*7B compared to UV5/1A2/NAT2*4 and UV5/1A2/NAT2*5B cells (p < 0.0001). MOCA also induced higher levels of oxidative stress in UV5/1A2/NAT2*7B cells. MOCA caused concentration-dependent increase in DNA damage in cryopreserved human hepatocytes (linear trend p < 0.001) which was NAT2 genotype dependent i.e., highest in rapid acetylators, lower in intermediate acetylators, and lowest in slow acetylators (p < 0.0001). Our findings show that N-acetylation and genotoxicity of MOCA is NAT2 genotype dependent and suggest that individuals possessing NAT2*7B are at higher risk to MOCA-induced mutagenicity. DNA damage, and oxidative stress. They confirm significant differences in genotoxicity between the NAT2*5B and NAT2*7B alleles, both of which are associated with slow acetylator phenotype.
Assuntos
Arilamina N-Acetiltransferase , Metilenobis (cloroanilina) , Cricetinae , Animais , Humanos , Cricetulus , Células CHO , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismo , Dano ao DNA , Acetiltransferases/genética , Genótipo , Estresse Oxidativo , Polimorfismo Genético , AcetilaçãoRESUMO
Arylamine N-acetyltransferase 2 has been related to drug side effects and cancer susceptibility; its protein structure and acetylation capacity results from the polymorphism's arrays on the NAT2 gene. Absorption, distribution, metabolism, and excretion, cornerstones of the pharmacological effects, have shown diversity patterns across populations, ethnic groups, and even interethnic variation. Although the 1000 Genomes Project database has portrayed the global diversity of the NAT2 polymorphisms, several populations and ethnicities remain underrepresented, limiting the comprehensive picture of its variation. The NAT2 clinical entails require a detailed landscape of its striking diversity. This systematic review spans the genetic and acetylation patterns from 164 articles from October 1992 to October 2020. Descriptive studies and controls from observational studies expanded the NAT2 diversity landscape. Our study included 243 different populations and 101 ethnic minorities, and, for the first time, we presented the global patterns in the Middle Eastern populations. Europeans, including its derived populations, and East Asians have been the most studied genetic backgrounds. Contrary to the popular perception, Africans, Latinos and Native Americans have been significantly represented in recent years. NAT2*4, *5B, and *6A were the most frequent haplotypes globally. Nonetheless, the distribution of *5B and *7B were less and more frequent in Asians, respectively. Regarding the acetylator status, East Asians and Native Americans harboured the highest frequencies of the fast phenotype, followed by South Europeans. Central Asia, the Middle East, and West European populations were the major carriers of the slow acetylator status. The detailed panorama presented herein, expands the knowledge about the diversity patterns to genetic and acetylation levels. These data could help clarify the controversial findings between acetylator states and the susceptibility to diseases and reinforce the utility of NAT2 in precision medicine.
Assuntos
Arilamina N-Acetiltransferase , Arilamina N-Acetiltransferase/genética , Arilamina N-Acetiltransferase/metabolismo , Acetilação , Polimorfismo Genético , Haplótipos , Fenótipo , GenótipoRESUMO
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.