RESUMO
Emerging evidence suggests that elevated levels of folic acid in the bloodstream may confer protection against Wuhan-SARS-CoV-2 infection and mitigate its associated symptoms. Notably, two comprehensive studies of COVID-19 patients in Israel and UK uncovered a remarkable trend, wherein individuals with heightened folic acid levels exhibited only mild symptoms and necessitated no ventilatory support. In parallel, research has underscored the potential connection between decreased folic acid levels and the severity of Covid-19 among hospitalized patients. Yet, the underlying mechanisms governing this intriguing inhibition remain elusive. In a quest to elucidate these mechanisms, we conducted a molecular dynamics simulation approach followed by a Raman spectroscopy study to delve into the intricate interplay between the folic acid metabolite, 7,8-dihydrofolate (DHF), and the angiotensin-converting enzyme ACE2 receptor, coupled with its interaction with the receptor-binding domain (RBD) of the Wuhan strain of SARS-CoV-2. Through a meticulous exploration, we scrutinized the transformation of the ACE2 + RBD complex, allowing these reactants to form bonds. This was juxtaposed with a similar investigation where ACE2 was initially permitted to react with DHF, followed by the exposure of the ACE2 + DHF complex to RBD. We find that DHF, when bonded to ACE2, functions as a physical barrier, effectively inhibiting the binding of the Wuhan strain RBD. This physicochemical process offers a cogent explanation for the observed inhibition of host cell infection in subjects receiving supplementary folic acid doses, as epidemiologically substantiated in multiple studies. This study not only sheds light on a potential avenue for mitigating SARS-CoV-2 infection but also underscores the crucial role of folic acid metabolites in host-virus interactions. This research paves the way for novel therapeutic strategies in the battle against COVID-19 and reinforces the significance of investigating the molecular mechanisms underlying the protective effects of folic acid in the context of viral infections.
Assuntos
COVID-19 , Ácido Fólico , SARS-CoV-2 , Humanos , Enzima de Conversão de Angiotensina 2 , Ácido Fólico/análogos & derivados , Ácido Fólico/metabolismo , Ácido Fólico/farmacologia , Simulação de Dinâmica Molecular , Ligação Proteica , Análise Espectral RamanRESUMO
Folate is an essential vitamin for vertebrate embryo development. Methotrexate (MTX) is a folate antagonist that is widely prescribed for autoimmune diseases, blood and solid organ malignancies, and dermatologic diseases. Although it is highly contraindicated for pregnant women, because it is associated with an increased risk of multiple birth defects, the effect of paternal MTX exposure on their offspring has been largely unexplored. Here, we found MTX treatment of adult medaka male fish (Oryzias latipes) causes cranial cartilage defects in their offspring. Small non-coding RNA (sncRNAs) sequencing in the sperm of MTX treated males identify differential expression of a subset of tRNAs, with higher abundance for specific 5' tRNA halves. Sperm RNA methylation analysis on MTX treated males shows that m5C is the most abundant and differential modification found in RNAs ranging in size from 50 to 90 nucleotides, predominantly tRNAs, and that it correlates with greater testicular Dnmt2 methyltransferase expression. Injection of sperm small RNA fractions from MTX-treated males into normal fertilized eggs generated cranial cartilage defects in the offspring. Overall, our data suggest that paternal MTX exposure alters sperm sncRNAs expression and modifications that may contribute to developmental defects in their offspring.
Assuntos
Metotrexato , Pequeno RNA não Traduzido , Animais , Masculino , Gravidez , Humanos , Feminino , Metotrexato/efeitos adversos , Metotrexato/metabolismo , Sêmen , Espermatozoides/metabolismo , Ácido Fólico/metabolismo , Pequeno RNA não Traduzido/genética , RNA de Transferência/genética , RNA de Transferência/metabolismoRESUMO
The folate metabolic cycle is an important biochemical process for the maintenance of cellular homeostasis, and is a widely studied pathway of cellular replication control in all organisms. In microorganisms such as M. tuberculosis (Mtb), for instance, dihydrofolate reductase (MtDHFR) is the enzyme commonly explored as a molecular target for the development of new antibiotics. In the same way, dihydropteroate synthase (MtDHPS) was studied extensively until the first multidrug-resistant strains of mycobacteria that could not be killed by sulfonamides were found. However, the other enzymes belonging to the metabolic cycle, until recently less explored, have drawn attention as potential molecular targets for obtaining new antituberculosis agents. Recent structural determinations and mechanism of action studies of Mtb flavin-dependent thymidylate synthase (MtFDTS) and MtRv2671, enzymes that acts on alternative metabolic pathways within the folate cycle, have greatly expanded the scope of potential targets that can be screened in drug design process. Despite the crystallographic elucidation of most cycle proteins, some enzymes, such as dihydrofolate synthase (MtDHFS) and serine hydroxylmethyltransferase (MtSHMT), remain underexplored. In this review, we highlight recent efforts towards the inhibitor design to achieve innovative antituberculosis agents and a brief history of all enzymes present in the folate metabolic cycle. In the final section of this work, we have presented the main synthetic strategies used to obtain the most promising inhibitors.
Assuntos
Antagonistas do Ácido Fólico , Mycobacterium tuberculosis , Antituberculosos/farmacologia , Antituberculosos/química , Antagonistas do Ácido Fólico/farmacologia , Ácido Fólico/química , Ácido Fólico/metabolismo , Mycobacterium tuberculosis/metabolismoRESUMO
Cancer cells are characterized by accelerated proliferation and an outstanding adaptation of their metabolic pathways to meet energy demands. The folate cycle, also known as folate metabolism or one-carbon metabolism, through enzymatic interconversions, provides metabolites necessary for nucleotide synthesis, methylation, and reduction power, helping to maintain the high rate of proliferation; therefore, the study of this metabolic pathway is of great importance in the study of cancer. Moreover, multiple enzymes involved in this cycle have been implicated in different types of cancer, corroborating the cell's adaptations under this pathology. During the last decade, nonalcoholic fatty liver disease has emerged as the leading etiology related to the rise in the incidence and deaths of hepatocellular carcinoma. Specifically, cholesterol accumulation has been a determinant promoter of tumor formation, with solid evidence that an enriched-cholesterol diet plays a crucial role in accelerating the development of an aggressive subtype of hepatocellular carcinoma compared to other models. In this review, we will discuss the most recent findings to understand the contribution of folate metabolism to cancer cells and tumor microenvironment while creating a link between the dynamics given by cholesterol and methylenetetrahydrofolate dehydrogenase 1-like, a key enzyme of the cycle located in the mitochondrial compartment.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patologia , Metilenotetra-Hidrofolato Desidrogenase (NADP)/metabolismo , Neoplasias Hepáticas/patologia , Ácido Fólico/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Microambiente TumoralRESUMO
Background: Homocysteine levels can be impacted by enzymes variations. Aim: To correlate MTHFR, MTR and MTRR variants with homocysteine levels in the blood and follicular fluid and assisted reproduction results. Material & methods:MTHFR (rs2274976, rs1801131, rs1801133), MTR (rs1805087) and MTRR (rs1801394) genotyping was performed by TaqMan assays and compared with homocysteine levels, measured by ELISA, to oocytes retrieved and to the pregnancy status of women with endometriosis and controls. Results: The MTR G allele and GG genotype were more common in patients with endometriosis. They also showed lower levels of homocysteine and more clinical gestations. Epistasis analysis showed a model associated with gestational results, composed of MTHFR+MTR variants (CC+AG). Conclusion: The summation effect of variants in genes participating in folate metabolism was associated with pregnancy status in Brazilian women. MTR variants were more observed in endometriosis patients, as well as lower follicular Hcy levels and increased clinical pregnancy results.
What was the aim of the study? To correlate genetic variants to homocysteine levels in the blood and oocyte surrounding fluid, and the results of assisted reproduction techniques. How was the study done? A total of 152 women with endometriosis and controls with male infertility were evaluated. DNA was extracted from blood for genetic analysis, and homocysteine levels were measured from the blood and oocyte surrounding fluid. Genetic results were correlated to homocysteine levels, oocyte quality and pregnancy status. What were the results? A specific genetic marker occurred more in endometriosis patients. They also showed lower levels of homocysteine and a tendency to more clinical gestations than controls. What do the results of the study mean? Endometriosis patients showed specific genetic markers and different levels of homocysteine compared with controls. These results can be helpful to predict gestational results.
Assuntos
5-Metiltetra-Hidrofolato-Homocisteína S-Metiltransferase , Endometriose , Ferredoxina-NADP Redutase , Homocisteína , Metilenotetra-Hidrofolato Redutase (NADPH2) , 5-Metiltetra-Hidrofolato-Homocisteína S-Metiltransferase/genética , Alelos , Endometriose/complicações , Endometriose/genética , Feminino , Ferredoxina-NADP Redutase/genética , Ácido Fólico/metabolismo , Genótipo , Homocisteína/sangue , Humanos , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Polimorfismo de Nucleotídeo Único , GravidezRESUMO
Although of unknown etiology, some mechanisms associated with the metabolic cycle of folate are speculated to be related to the genesis of amyotrophic lateral sclerosis (ALS). Thus, the aim of the study was to analyze the role of genetic polymorphisms rs1051266 in SLC19A1 gene and rs1805087 in MTR gene and their associations with ALS development. A case-control study was conducted with 101 individuals with ALS and 119 individuals without diagnosis of neurodegenerative diseases, from the Brazilian central population. The polymorphisms were determined using the polymerase chain reaction-restriction fragment length polymorphism technique. The results showed no statistically significant differences, even when genotypes were analyzed by the dominant, recessive, codominant, and overdominant inheritance models. It was observed a statistical significance relating alcohol consumption with individuals in the case group (p = 0.01). Therefore, the need for more studies to evaluate the influence of genetic variants is highlighted, seeking to provide information on the etiopathogenesis of ALS.
Assuntos
Esclerose Lateral Amiotrófica , Esclerose Lateral Amiotrófica/genética , Carbono , Estudos de Casos e Controles , Ácido Fólico/metabolismo , Predisposição Genética para Doença , Genótipo , Humanos , Polimorfismo de Nucleotídeo ÚnicoRESUMO
OBJECTIVE: The study aim to investigate MTHFR C677T, MTHFR A1298C, RFC1 A80G, MTR A2756G, CBS 844ins68, MTRR A66G polymorphisms in Down syndrome (DS) parents. METHODS: Polymorphisms were evaluated in 35 mothers and 24 fathers of individuals with free trisomy of chromosome 21 confirmed by karyotype. The control group included 26 mothers and 26 fathers who had no children with DS. The molecular analysis was performed by polymerase chain reaction and restriction fragment length polymorphism (reaction chain polymerase restriction fragment length polymorphism) or polymerase chain reaction. The χ2 test (chi-square) was used to compare allele's differences among the study and the control group. Hardy-Weinberg equilibrium model was performed by χ2 testing. Multiple logistic regression models and binary logistic regression used to determine the association between polymorphisms and parental DS risk. RESULTS: This study did not reveal any significant difference in frequencies of polymorphisms. The haplotype analysis did not reveal linkage disequilibrium. The logistic regression analysis did not demonstrate differences between the groups. However, the binary logistic regression showed a higher frequency of the polymorphic homozygote genotype in DS parent group to codominant and dominant model in the RFC1 A80G. CONCLUSION: In conclusion, although the screening results were significant only to the RFC1 A80G polymorphism, the other determinations of the genetic factors associated with abnormal chromosome segregation could be helpful in future studies, including other polymorphisms involved in folate metabolism.
Assuntos
Síndrome de Down , Ferredoxina-NADP Redutase , Ácido Fólico , Síndrome de Down/genética , Feminino , Ferredoxina-NADP Redutase/genética , Ácido Fólico/metabolismo , Humanos , Masculino , Pais , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Irinotecan (IRN) is a semisynthetic derivative of camptothecin that acts as a topoisomerase I inhibitor. IRN is used worldwide for the treatment of several types of cancer, including colorectal cancer, however its use can lead to serious adverse effects, as diarrhea and myelosuppression. Liposomes are widely used as drug delivery systems that can improve chemotherapeutic activity and decrease side effects. Liposomes can also be pH-sensitive to release its content preferentially in acidic environments, like tumors, and be surface-functionalized for targeting purposes. Herein, we developed a folate-coated pH-sensitive liposome as a drug delivery system for IRN to reach improved tumor therapy without potential adverse events. Liposomes were prepared containing IRN and characterized for particle size, polydispersity index, zeta potential, concentration, encapsulation, cellular uptake, and release profile. Antitumor activity was investigated in a murine model of colorectal cancer, and its toxicity was evaluated by hematological/biochemical tests and histological analysis of main organs. The results showed vesicles smaller than 200 nm with little dispersion, a surface charge close to neutral, and high encapsulation rate of over 90%. The system demonstrated prolonged and sustained release in pH-dependent manner with high intracellular drug delivery capacity. Importantly, the folate-coated pH-sensitive formulation had significantly better antitumor activity than the pH-dependent system only or the free drug. Tumor tissue of IRN-containing groups presented large areas of necrosis. Furthermore, no evidence of systemic toxicity was found for the groups investigated. Thus, our developed nanodrug IRN delivery system can potentially be an alternative to conventional colorectal cancer treatment.
Assuntos
Neoplasias Colorretais/tratamento farmacológico , Ácido Fólico/metabolismo , Irinotecano/administração & dosagem , Lipídeos/química , Inibidores da Topoisomerase I/administração & dosagem , Animais , Linhagem Celular Tumoral , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Preparações de Ação Retardada , Composição de Medicamentos , Liberação Controlada de Fármacos , Ácido Fólico/química , Concentração de Íons de Hidrogênio , Irinotecano/química , Irinotecano/metabolismo , Lipossomos , Camundongos Endogâmicos BALB C , Necrose , Fatores de Tempo , Inibidores da Topoisomerase I/química , Inibidores da Topoisomerase I/metabolismo , Carga Tumoral/efeitos dos fármacosRESUMO
Down syndrome (DS) is the most common chromosomal disorder, resulting from the failure of normal chromosome 21 segregation. Studies have suggested that impairments within the one-carbon metabolic pathway can be of relevance for the global genome instability observed in mothers of individuals with DS. Based on the association between global DNA hypomethylation, genome instability, and impairments within the one-carbon metabolic pathway, the present study aimed to identify possible predictors, within the one-carbon metabolism, of global DNA methylation, measured by methylation patterns of LINE-1 and Alu repetitive sequences, in mothers of individuals with DS and mothers of individuals without the syndrome. In addition, we investigated one-carbon genetic polymorphisms and metabolites as maternal predisposing factors for the occurrence of trisomy 21 in children. Eighty-three samples of mothers of children with DS with karyotypically confirmed free trisomy 21 (case group) and 84 of mothers who had at least one child without DS or any other aneuploidy were included in the study. Pyrosequencing assays were performed to access global methylation. The results showed that group affiliation (case or control), betaine-homocysteine methyltransferase (BHMT) G742A and transcobalamin 2 (TCN2) C776G polymorphisms, and folate concentration were identified as predictors of global Alu DNA methylation values. In addition, thymidylate synthase (TYMS) 28-bp repeats 2R/3R or 3R/3R genotypes are independent maternal predisposing factors for having a child with DS. This study adds evidence that supports the association of impairments in the one-carbon metabolism, global DNA methylation, and the possibility of having a child with DS.
Assuntos
Carbono/metabolismo , Metilação de DNA/genética , Síndrome de Down/genética , Síndrome de Down/metabolismo , Estudo de Associação Genômica Ampla , Instabilidade Genômica/genética , Relações Mãe-Filho , Mães , Adolescente , Adulto , Idoso , Elementos Alu/genética , Betaína-Homocisteína S-Metiltransferase/genética , Betaína-Homocisteína S-Metiltransferase/metabolismo , Feminino , Ácido Fólico/metabolismo , Predisposição Genética para Doença/genética , Humanos , Elementos Nucleotídeos Longos e Dispersos/genética , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Timidilato Sintase/genética , Transcobalaminas/genética , Transcobalaminas/metabolismo , Adulto JovemRESUMO
BACKGROUND: DNA methylation is the best epigenetic mechanism for explaining the interactions between nutrients and genes involved in intrauterine growth and development programming. A possible contributor of methylation abnormalities to congenital heart disease is the folate methylation regulatory pathway; however, the mechanisms and methylation patterns of VSD-associated genes are not fully understood. OBJECTIVE: To determine if maternal dietary intake of folic acid (FA) is related to the methylation status (MS) of VSD-associated genes (AXIN1, MTHFR, TBX1, and TBX20). METHODS: Prospective case-control study; 48 mothers and their children were evaluated. The mothers' dietary variables were collected through a food frequency questionnaire focusing on FA and the consumption of supplements with FA. The MS of promoters of genes was determined in the children. RESULTS: The intake of FA supplements was significantly higher in the control mothers. In terms of maternal folic acid consumption, significant differences were found in the first trimester of pregnancy. Significant differences were observed in the MS of MTHFR and AXIN1 genes in VSD and control children. A correlation between maternal FA supplementation and MS of AXIN1 and TBX20 genes was found in control and VSD children, respectively. CONCLUSIONS: A lower MS of AXIN1 genes and a higher MS of TBX20 genes is associated with FA maternal supplementation.