RESUMO
The Oomycetes fungus Phytophthora spp. which causes Abnormal leaf fall (ALF) disease poses a significant threat as one of the most devastating diseases affecting rubber trees in India. A total of 30 Phytophthora isolates were obtained from ALF-affected samples collected during the Southwest monsoon season of Kerala. The colony morphology of Phytophthora isolates revealed eight different types of growth patterns, with stellate, stellate striated, and petaloid patterns growing rapidly, whereas chrysanthemum pattern grew slowly. Sporangia were papillate to non-papillate in various shapes, and sporangiophores exhibited simple, simple sympodial, or irregularly branching patterns. Highly virulent isolates exhibited petaloid morphology and rapid growth rates. Regardless of their virulence, all isolates showed susceptibility to the fungicide metalaxyl. Under in vitro conditions, the highly virulent isolate (R17) from rubber caused severe infections in chili, brinjal, and tomato with brown water-soaked lesions. Sequence analysis and multi-locus phylogeny of Internal transcribed spacer (ITS), cCytochrome c oxidase 1 (COX 1), Heat shock protein 90 (HSP 90), and Ribosomal protein L10 (RPL 10) confirmed the pathogen as Phytophthora meadii. A comprehensive understanding of both morphological and molecular traits of P. meadii is crucial for precise identification and future genetic variability studies.
Assuntos
Hevea , Filogenia , Phytophthora , Doenças das Plantas , Índia , Phytophthora/genética , Phytophthora/classificação , Doenças das Plantas/microbiologia , Doenças das Plantas/parasitologia , Hevea/microbiologia , Hevea/parasitologia , Tipagem de Sequências Multilocus , Folhas de Planta/microbiologia , Folhas de Planta/parasitologia , Análise de Sequência de DNA , Virulência , DNA Espaçador Ribossômico/genética , Prevalência , Análise por Conglomerados , Fungicidas Industriais/farmacologia , Alanina/análogos & derivadosRESUMO
This work presents a study on the effects of periodic boundary conditions (PBC) on the energetic/structural properties and hydrogen bond dynamics (HB) using molecular dynamics (MD) simulations of peptide membranes composed of alanine and histidine. Our results highlight that simulations using small surface areas for the peptide membrane may result in nonconvergent values for membrane properties, which are only observed in regions simulated at a certain distance from the PBCs. Specifically, regarding hydrogen bonds, a property pervasive in peptide membranes, our findings indicate a significant increase in the lifetime of these interactions, reaching values â¼19% higher when observed in structures free from PBCs. For peptide mobility in these nanomembranes, our results compare regions simulated directly under the influence of PBCs with regions free from these conditions, emphasizing greater mobility of amino acid psi/phi angles in the latter model.
Assuntos
Ligação de Hidrogênio , Simulação de Dinâmica Molecular , Nanoestruturas , Peptídeos , Nanoestruturas/química , Peptídeos/química , Histidina/química , Alanina/químicaRESUMO
The COVID-19 pandemic has resulted in millions of fatalities worldwide. The case of pediatric cancer patients stands out since, despite being considered a population at risk, few studies have been carried out concerning symptom detection or the description of the mechanisms capable of modifying the course of the COVID-19 disease, such as the interaction and response between the virus and the treatment given to cancer patients. By synthesizing existing studies, this paper aims to expose the treatment challenges for pediatric patients with COVID-19 in an oncology context. Additionally, this updated review includes studies that utilized the antiviral agents Remdesivir and PaxlovidTM in pediatric cancer patients. There is no specific treatment designed exclusively for pediatric cancer patients dealing with COVID-19, and it is advisable to avoid self-medication to prevent potential side effects. Managing COVID-19 in pediatric cancer patients is indeed a substantial challenge. New strategies, such as chemotherapy application rooms, have been implemented for children with cancer who were positive for COVID-19 but asymptomatic since the risk of disease progression is greater than the risk of complications from SARS-CoV-2.
Assuntos
Alanina , Antivirais , COVID-19 , Neoplasias , SARS-CoV-2 , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/terapia , Neoplasias/complicações , COVID-19/epidemiologia , Criança , Antivirais/uso terapêutico , SARS-CoV-2/efeitos dos fármacos , Alanina/análogos & derivados , Alanina/uso terapêutico , Monofosfato de Adenosina/análogos & derivados , Monofosfato de Adenosina/uso terapêutico , Tratamento Farmacológico da COVID-19 , PandemiasRESUMO
Allosteric modulation plays a critical role in enzyme functionality and requires a deep understanding of the interactions between the active and allosteric sites. γ-Secretase (GS) is a key therapeutic target in the treatment of Alzheimer's disease (AD), through its role in the synthesis of amyloid ß peptides that accumulate in AD patients. This study explores the structure and dynamic effects of GS modulation by E2012 binding, employing well-tempered metadynamics and conventional molecular dynamics simulations across three binding scenarios: (1) GS enzyme with and without L458 inhibitor, (2) the GS-substrate complex together with the modulator E2012 in two different binding modes, and (3) E2012 interacting with a C99 substrate fragment. Our findings reveal that the presence of L458 induces conformational changes that contribute to stabilization of the GS enzyme dynamics, previously reported as a key factor that allowed the resolution of the cryo-EM structure and the enhanced binding of E2012. Furthermore, we identified the most favorable binding site for E2012 within the GS-substrate complex, uncovering significant modulatory effects and a complex network of interactions that influence the position of the substrate for catalysis. In addition, we explore a potential substrate-modulator binding before the formation of the enzyme-substrate complex. The insights gained from our study emphasize the importance of these interactions in the development of potential therapeutic interventions that target the functionality of the GS enzyme in AD.
Assuntos
Alanina/análogos & derivados , Secretases da Proteína Precursora do Amiloide , Simulação de Dinâmica Molecular , Ligação Proteica , Secretases da Proteína Precursora do Amiloide/metabolismo , Secretases da Proteína Precursora do Amiloide/química , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Especificidade por Substrato , Humanos , Conformação Proteica , Regulação Alostérica/efeitos dos fármacos , AzepinasRESUMO
BACKGROUND: Duchenne muscular dystrophy (DMD) is a severe form of muscular dystrophy without an effective treatment, caused by mutations in the DMD gene, leading to the absence of dystrophin. DMD results in muscle weakness, loss of ambulation, and death at an early age. Metabolomics studies in mdx mice, the most used model for DMD, reveal changes in metabolites associated with muscle degeneration and aging. In DMD, the tongue muscles exhibit unique behavior, initially showing partial protection against inflammation but later experiencing fibrosis and loss of muscle fibers. Certain metabolites and proteins, like TNF-α and TGF-ß, are potential biomarkers for dystrophic muscle characterization. METHODS: To investigate disease progression and aging, we utilized young (1 month old) and old (21-25 months old) mdx and wild-type tongue muscles. Metabolite changes were analyzed using 1H nuclear magnetic resonance, while TNF-α and TGF-ß were assessed using Western blotting to examine inflammation and fibrosis. Morphometric analysis was conducted to assess the extent of myofiber damage between groups. RESULTS: The histological analysis of the mid-belly tongue showed no differences between groups. No differences were found between the concentrations of metabolites from wild-type or mdx whole tongues of the same age. The metabolites alanine, methionine, and 3-methylhistidine were higher, and taurine and glycerol were lower in young tongues in both wild type and mdx (p < 0.001). The metabolites glycine (p < 0.001) and glutamic acid (p = 0.0018) were different only in the mdx groups, being higher in young mdx mice. Acetic acid, phosphocreatine, isoleucine, succinic acid, creatine, and the proteins TNF-α and TGF-ß had no difference in the analysis between groups (p > 0.05). CONCLUSIONS: Surprisingly, histological, metabolite, and protein analysis reveal that the tongue of old mdx remains partially spared from the severe myonecrosis observed in other muscles. The metabolites alanine, methionine, 3-methylhistidine, taurine, and glycerol may be effective for specific assessments, although their use for disease progression monitoring should be cautious due to age-related changes in the tongue muscle. Acetic acid, phosphocreatine, isoleucine, succinate, creatine, TNF-α, and TGF-ß do not vary with aging and remain constant in spared muscles, suggesting their potential as specific biomarkers for DMD progression independent of aging.
Assuntos
Distrofia Muscular de Duchenne , Camundongos , Animais , Distrofia Muscular de Duchenne/genética , Fator de Necrose Tumoral alfa/genética , Creatina , Camundongos Endogâmicos mdx , Fosfocreatina , Glicerol , Isoleucina , Fibras Musculares Esqueléticas , Metionina , Racemetionina , Ácido Acético , Alanina , Progressão da DoençaRESUMO
Parkinson's-disease (PD) is an incurable, age-related neurodegenerative disease, and its global prevalence of disability and death has increased exponentially. Although motor symptoms are the characteristic manifestations of PD, the clinical spectrum also contains a wide variety of non-motor symptoms, which are the main cause of disability and determinants of the decrease in a patient's quality of life. Noteworthy in this regard is the stress on the cardiac system that is often observed in the course of PD; however, its effects have not yet been adequately researched. Here, an untargeted metabolomics approach was used to assess changes in cardiac metabolism in the 6-hydroxydopamine model of PD. Beta-sitosterol, campesterol, cholesterol, monoacylglycerol, α-tocopherol, stearic acid, beta-glycerophosphoric acid, o-phosphoethanolamine, myo-inositol-1-phosphate, alanine, valine and allothreonine are the metabolites that significantly discriminate parkinsonian rats from sham counterparts. Upon analysis of the metabolic pathways with the aim of uncovering the main biological pathways involved in concentration patterns of cardiac metabolites, the biosynthesis of both phosphatidylethanolamine and phosphatidylcholine, the glucose-alanine cycle, glutathione metabolism and plasmalogen synthesis most adequately differentiated sham and parkinsonian rats. Our results reveal that both lipid and energy metabolism are particularly involved in changes in cardiac metabolism in PD. These results provide insight into cardiac metabolic signatures in PD and indicate potential targets for further investigation.
Assuntos
Doenças Neurodegenerativas , Doença de Parkinson , Ratos , Animais , Doença de Parkinson/metabolismo , Oxidopamina , Doenças Neurodegenerativas/complicações , Qualidade de Vida , AlaninaRESUMO
INTRODUCTION AND OBJECTIVES: Renal and bone impairment has been reported in chronic hepatitis B (CHB) patients receiving long-term tenofovir disoproxil fumarate (TDF) therapy. This study aimed to assess the incidence of renal and bone impairment in CHB patients with long-term TDF therapy and to identify the changes in bone mineral density (BMD) and renal function in these patients after switching to entecavir (ETV) or tenofovir alafenamide (TAF). MATERIALS AND METHODS: This retrospective study collected clinical data from CHB patients who received TDF monotherapy over 96 weeks. The changes in BMD and renal function were analyzed after 96 weeks of switching antiviral regimens (ETV or TAF) or maintenance TDF. RESULTS: At baseline, 154 patients receiving TDF monotherapy over 96 weeks were enrolled, with a younger median age of 36.75 years, 35.1% (54/154) of patients experienced elevated urinary ß2 microglobulin and 20.1% (31/154) of patients had reduced hip BMD (T<-1). At week 96, among the 123 patients with baseline normal BMD, patients who maintained TDF (n=85) had experienced a decrease in hip BMD, while patients who switched antiviral regimens (n=38) experienced an increase (-13.97% vs 2.34%, p<0.05). Among patients with a baseline reduced BMD (n=31), the alterations in BMD were similar in patients who maintained TDF (n=5) and those who switched antiviral regimens (n=26) (-15.81% vs 7.35%, p<0.05). Irrespective of baseline BMD status, renal function decreased significantly in patients who maintained TDF and improved in patients who switched antiviral regimens. CONCLUSIONS: Younger CHB patients on long-term TDF therapy are at high risk for bone and renal impairment, with the risk being reduced when switched to ETV or TAF.
Assuntos
Hepatite B Crônica , Humanos , Adulto , Tenofovir/efeitos adversos , Hepatite B Crônica/diagnóstico , Hepatite B Crônica/tratamento farmacológico , Estudos Retrospectivos , Alanina/uso terapêutico , Adenina/uso terapêutico , Rim/fisiologia , Antivirais/efeitos adversos , Resultado do TratamentoRESUMO
Interleukin 6 (IL6) is an multifunctional cytokine that modulates several biological responses, including glucose metabolism. However, its acute effects on hepatic glucose release are still uncertain. The main purpose of this study was to investigate the effects of IL6 on gluconeogenesis from several glucose precursors (alanine, pyruvate and glutamine) and on the suppressive action of insulin on cAMP-stimulated glycogen catabolism in rat liver. IL6 effect on insulin peripheral sensitivity was also evaluated. IL6 was injected intravenously into rats and, 1 h later, gluconeogenesis and glycogenolysis were assessed in liver perfusion and peripheral insulin sensitivity by insulin tolerance test (ITT). IL6 intravenous injection increased hepatic glucose production from alanine, without changing pyruvate, lactate and urea production. IL6 injection also increased hepatic glucose production from pyruvate and glutamine. In addition, IL6 decreased the suppressive effect of insulin on cAMP-stimulated glucose and lactate production and glycogenolysis, without affecting pyruvate production. Furthermore, IL6 reduced the plasma glucose disappearance constant (kITT), an indicator of insulin resistance. In conclusion, IL6 acutely increased hepatic glucose release (gluconeogenesis and glycogenolysis) by a mechanism that likely involved the induction of insulin resistance in the liver, as evidenced by the reduced suppressive effect of insulin on cAMP-stimulated glycogen catabolism. In consistency, IL6 acutely induced peripheral insulin resistance.
Assuntos
Glicogenólise , Resistência à Insulina , Ratos , Animais , Gluconeogênese , Insulina/farmacologia , Insulina/metabolismo , Interleucina-6/metabolismo , Glutamina/metabolismo , Glutamina/farmacologia , Glucose/farmacologia , Glucose/metabolismo , Glicogênio/metabolismo , Glicogênio/farmacologia , Fígado/metabolismo , Ácido Láctico/farmacologia , Ácido Láctico/metabolismo , Piruvatos/metabolismo , Piruvatos/farmacologia , Alanina/farmacologia , Alanina/metabolismo , GlicemiaRESUMO
Mycosporine-like amino acids (MAAs) are natural UV-absorbing sunscreens that evolved in cyanobacteria and algae to palliate harmful effects from obligatory exposure to solar radiation. Multiple lines of evidence prove that in cyanobacteria all MAAs are derived from mycosporine-glycine, which is typically modified by an ATP-dependent ligase encoded by the gene mysD. The function of the mysD ligase has been experimentally described but haphazardly named based solely upon sequence similarity to the d-alanine-d-alanine ligase of bacterial peptidoglycan biosynthesis. Combining phylogeny and alpha-fold tertiary protein structure prediction unambiguously distinguished mysD from d-alanine-d-alanine ligase. The renaming of mysD to mycosporine-glycine-amine ligase (MG-amine ligase) using recognised enzymology rules of nomenclature is, therefore, proposed, and considers relaxed specificity for several different amino acid substrates. The evolutionary and ecological context of MG-amine ligase catalysis merits wider appreciation especially when considering exploiting cyanobacteria for biotechnology, for example, producing mixtures of MAAs with enhanced optical or antioxidant properties.
Assuntos
Aminoácidos , Cianobactérias , Aminoácidos/química , Glicina/metabolismo , Cianobactérias/metabolismo , Alanina/metabolismo , Aminas/metabolismo , Ligases/metabolismo , Raios UltravioletaRESUMO
Two field experiments were conducted during 2019 and 2020 summer seasons at the experimental station of national research center, Al-Nubaryia district, El-Behaira Governorate, Egypt, to study the effect of Phenyl alanine and Aspartic acid foliar fertilizers at rates of (0.0, 50, 75 and 100 ppm) on morphological characters, photosynthetic pigments, seed yield and its components as well as seed quality of groundnut grown under sandy soil. Results indicated superiority of aspartic acid over phenyl alanine on increasing different growth parameters, chlorophyll b, biological and seed yields/plant, biological, seed and oil yields (kg/fed.), % of carbohydrate in peanut seeds. Meanwhile, phenyl alanine was superior on increasing carotenoids, indole acetic acid, phenolics, free amino acids, flavonoids, Lycopene, ß-Carotene contents, antioxidant activity expressed as (1,1-diphenyl-2-picrylhydrazyl DPPH %) and shilling percentage. In addition, aspartic acid and phenyl alanine with various levels caused significant increases in growth and seed yield quantity and quality of peanut plants through increases in photosynthetic pigments, indole acetic acid, phenolics and free amino acids contents. Aspartic acid was more effective than phenyl alanine, Foliar treatment with 100 mg/L aspartic acid increased oil yield (700.36 over 568.05 ton/fed.) and seed yield (1531.98 over 1253.49 kg/fed.). Finally, it can conclude that using aspartic acid and phenyl alanine as foliar treatment improved growth and yield of ground nut plants under sandy soil.
Assuntos
Arachis , Solo , Solo/química , Areia , Aminoácidos , Ácido Aspártico , AlaninaRESUMO
This research characterizes key metabolites in the leaf from Citronella gongonha Martius (Mart.) Howard (Cardiopteridaceae). All metabolites were assessed in intact leaf tissue by proton (1H) high-resolution magic angle spinning (HR-MAS) nuclear magnetic resonance (NMR) spectroscopy integrated with the principal component analysis (PCA) to depict molecular association with the seasonal change. The major 'known unknown' metabolites detected in 1H HR-MAS NMR were derivatives of flavonoid, polyphenolic and monoterpenoid compounds such as kaempferol-3-O-dihexoside, caffeoyl glucoside (2), 3-O-caffeoylquinic acid (3), 5-O-caffeoylquinic acid (4), kingiside (5), 8-epi-kingisidic acid (6), (7α)-7-O-methylmorroniside (7), (7ß)-7-O-methylmorroniside (8) and alpigenoside (9) together with the universally occurring sucrose (10), α-glucoses (11, 12), alanine (13), and fatty (linolenic) acid (14). Several of the major metabolites (1, 2-9) were additionally confirmed by liquid chromatography tandem mass spectrometry (LC-MS/MS). In regard with the PCA results, metabolites 1, 2-9 and 14 were influenced by seasonal variation and/or from further (a) biotic environmental conditions. The findings in this work indicate that C. gongonha Mart. is an effective medicinal plant by preserving particularly compounds 2, 3-9 in abundant amounts. Because of close susceptibility with seasonal shift and ecological trends, further longitudinal studies are needed to realize the physiology and mechanism involved in the production of these and new metabolites in this plant under controlled conditions. Also, future studies are recommended to classify different epimers, especially of the phenolics and monoterpenoids in the given plant.
Assuntos
Cymbopogon , Magnoliopsida , Quempferóis/metabolismo , Prótons , Cromatografia Líquida , Espectrometria de Massas em Tandem , Metabolômica/métodos , Espectroscopia de Ressonância Magnética/métodos , Folhas de Planta/metabolismo , Monoterpenos/análise , Alanina/metabolismo , Sacarose/metabolismo , Glucosídeos/metabolismoRESUMO
BACKGROUND: Periodontitis is resulted from a complex interaction between genetics and epigenetics, microbial factors, and the host response. Metabolomics analyses reflect both the steady-state physiological equilibrium of cells or organisms as well as their dynamic metabolic responses to environmental stimuli. AIM OF REVIEW: This systematic review of the literature aimed to assess which low molecular weight metabolites are more often found in biological fluids of individuals with periodontitis compared to individuals with gingivitis or periodontal health. KEY SCIENTIFIC CONCEPTS OF REVIEW: All the included studies employed untargeted analysis. One or more biological fluids were analyzed, including saliva (n = 14), gingival crevicular fluid (n = 6), mouthwash (n = 1), serum (n = 3) and plasma (n = 1). Fifty-six main metabolites related to periodontitis have been identified in at least two independent studies by NMR spectroscopy or MS-based metabolomics. Saliva was the main biological fluid sampled. It is noteworthy that 14 metabolites of the 56 detected were identified as main metabolites in all studies that sampled the saliva. The majority of metabolites found consistently among studies were amino acids, organic acids and derivates: acetate, alanine, butyrate, formate, GABA, lactate, propionate, phenylalanine and valine. They were either up- or down-regulated in the studies or this information was not mentioned. The main metabolic pathway was related to phenylalanine, tyrosine and tryptophan biosynthesis. Metabolites more frequently found in individuals with periodontitis were related to both the host and to microorganism responses. Future studies are needed, and they should follow some methodological standards to facilitate their comparison.
Assuntos
Doenças Periodontais , Periodontite , Humanos , Metabolômica , Antissépticos Bucais , Propionatos , Triptofano , Periodontite/metabolismo , Formiatos , Fenilalanina , Butiratos , Lactatos , Tirosina , Alanina , Valina , Ácido gama-AminobutíricoRESUMO
Naringin (Nar) has been reported to exert potential hepatoprotective effects against acetaminophen (APAP)-induced injury. Mitochondrial dysfunction plays an important role in APAP-induced liver injury. However, the protective mechanism of Nar against mitochondrial damage has not been elucidated. Therefore, the aim of this study was to investigate the hepatoprotective effects of Nar against APAP and the possible mechanisms of actions. Primary rat hepatocytes and HepG2 cells were utilized to establish an in vitro model of APAP-induced hepatotoxicity. The effect of APAP and Nar on cell viability was evaluated by a CCK8 assay and detection of the concentrations of alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase. The cellular concentrations of biomarkers of oxidative stress were measured by ELISA. The mRNA expression levels of APAP-related phase II enzymes were determined by real-time PCR. The protein levels of Nrf2, phospho (p)-AMPK/AMPK, and biomarkers of mitochondrial dynamics were determined by western blot analysis. The mitochondrial membrane potential (MMP) was measured by high-content analysis and confocal microscopy. JC-1 staining was performed to evaluate mitochondrial depolarization. Nar pretreatment notably prevented the marked APAP-induced hepatocyte injury, increases in oxidative stress marker expression, reductions in the expression of phase II enzymes, significant loss of MMP, mitochondrial depolarization, and mitochondrial fission in vitro. In conclusion, Nar alleviated APAP-induced hepatocyte and mitochondrial injury by activating the AMPK/Nrf2 pathway to reduce oxidative stress in vitro. Applying Nar for the treatment of APAP-induced liver injury might be promising.
Assuntos
Doença Hepática Crônica Induzida por Substâncias e Drogas , Doença Hepática Induzida por Substâncias e Drogas , Animais , Ratos , Acetaminofen/toxicidade , Acetaminofen/metabolismo , Alanina/metabolismo , Alanina/farmacologia , Alanina Transaminase , Proteínas Quinases Ativadas por AMP/metabolismo , Aspartato Aminotransferases , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Doença Hepática Crônica Induzida por Substâncias e Drogas/metabolismo , Lactato Desidrogenases/metabolismo , Fígado/metabolismo , Dinâmica Mitocondrial , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , RNA Mensageiro/metabolismo , Transdução de SinaisRESUMO
BACKGROUND: Tocilizumab (TCZ) is a new therapeutic alternative for severe cases of COVID-19 pneumonia. AIM: To evaluate the cumulative incidence (CI) of suspected adverse drug reactions (ADR) from TCZ in adult patients with COVID-19. MATERIAL AND METHODS: An active pharmacological surveillance protocol was carried out in patients older than 18 years old, who received at least one dose of TCZ between May and August 2020 at a clinical hospital. Non-infectious ADRs were categorized according to the Common Terminology Criteria for Adverse Events and the development of infection was classified as present or absent. Causality and preventability of ADRs were determined with the Naranjo Algorithm and the modified Schumock & Thornton criteria, respectively. RESULTS: The CI of ADRs caused by TCZ was 69.6% (95% confidence intervals (CI): 63.5-76.6). A rise in alanine and aspartate aminotransferases and the development of infections were the most frequent adverse events. Seventy-four percent were considered mild in severity. Sixty two percent of suspected non-infectious ADRs were classified as probable and all the infectious events as Possible. Of the ADRs observed, 33% were preventable. CONCLUSIONS: The occurrence of ADRs after the use of TCZ is frequent, of mild severity, and in one third of the cases, preventable. We suggest monitoring blood count, liver function tests and ruling out infection prior to TCZ administration.
Assuntos
Tratamento Farmacológico da COVID-19 , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Adolescente , Adulto , Alanina , Anticorpos Monoclonais Humanizados , Aspartato Aminotransferases , HumanosRESUMO
MLL3, also known as KMT2C, is a lysine mono-methyltransferase in charge of the writing of an epigenetic mark on lysine 4 from histone 3. The catalytic site of MLL3 is composed of four tyrosines, namely, Y44, Y69, Y128, and Y130. Tyrosine residues are highly conserved among lysine methyltransferases' catalytic sites, although their complete function is still unclear. The exploration of how modifications on these residues from the enzymatic machinery impact the enzymatic activity of MLL3 could shed light transversally into the inner functioning of enzymes with similar characteristics. Through the use of QMMM calculations, we focus on the effect of the mutation of each tyrosine from the catalytic site on the enzymatic activity and the product specificity in the current study. While we found that the mutations of Y44 and Y128 by phenylalanine inactivated the enzyme, the mutation of Y128 by alanine reactivated the enzymatic activity of MLL3. Moreover, according to our models, the Y128A mutant was even found to be capable of di- and tri-methylate lysine 4 from histone 3, what would represent a gain of function mutation, and could be responsible for the development of diseases. Finally, we were able to establish the inactivation mechanism, which involved the use of Y130 as a water occlusion structure, whose conformation, once perturbed by its mutation or Y128 mutant, allows the access of water molecules that sequester the electron pair from lysine 4 avoiding its methylation process and, thus, increasing the barrier height.
Assuntos
Histona-Lisina N-Metiltransferase , Histonas , Alanina/genética , Sítios de Ligação , Epigênese Genética , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Lisina/metabolismo , Metilação , Fenilalanina/metabolismo , Tirosina/metabolismo , Água/metabolismoRESUMO
BACKGROUND/OBJECTIVE: There is evidence that metabolic profile changes after Roux-Y gastric bypass (RYGB), especially due to modifications in the gastrointestinal tract. In addition, previous studies have suggested that probiotics can modify the microbiome and produce metabolites important for metabolic health maintenance. In this sense, the aim of this study was to verify the influence of probiotic supplementation on the plasma metabolite profile after RYGB. METHODS: This was a randomized, double-blind, placebo-controlled clinical trial conducted with 31 patients subjected to RYGB surgery, randomized in probiotic group that was supplemented with a probiotic supplement (FloraVantage®) for 3 months after surgery or a placebo group. Plasma metabonomics was performed using nuclear magnetic resonance (NMR) at the preoperative period (T0) and at 45-50 days (T1) and 90-95 days (T2) during the postoperative period/intervention. RESULTS: Reductions in trimethylamine-N-oxide (TMAO) and alanine were observed in both groups, however this reduction was greater in the probiotic group (TMAO 13.82%, p = 0.01 and alanine 14.03%, p = 0.03) at T2. Additionally, ß-hydroxybutyrate (BHB) levels increased 10.77% in the probiotic group (p = 0.03) compared to the placebo group at T2. CONCLUSION: Supplementation with Lactobacillus acidophilus NCFM and Bifidobacterium lactis Bi-07 was able to associate with significant differences in relevant plasma metabolites associated with improved metabolic health.
Assuntos
Derivação Gástrica , Probióticos , Humanos , Ácido 3-Hidroxibutírico , Estudos Prospectivos , Glicemia/metabolismo , Probióticos/uso terapêutico , Suplementos Nutricionais , Método Duplo-Cego , Alanina , ÓxidosRESUMO
Alguns suplementos exercem atividade tamponante e têm sido reconhecidos por sua contribuição anaeróbica em exercícios de alta intensidade, retardando a fadiga muscular periférica e potencializando assim a performance esportiva. O objetivo deste estudo foi comparar o benefício ergogênico no tamponamento e dano muscular, dos suplementos beta alanina, bicarbonato de sódio e suco de limão por meio da dosagem de lactato sanguíneo e creatinofosfoquinase (CPK) e na performance de ciclistas submetidos a exercício anaeróbico de alta intensidade. Estudo transversal crossover, realizado em quatro etapas, com ciclistas do sexo masculino. A suplementação foi constituída de 6 g de beta alanina, 0,2 g/kg de bicarbonato de sódio e 30 mL de suco de limão. Lactato sanguíneo e enzima CPK foram dosados pelo método teste ultravioleta enzimático e cinético, respectivamente, em cada uma das etapas. A performance correspondeu à rotação máxima por minuto (RPM) da Air Bike. Participaram do estudo sete ciclistas, com média de idade de 31,14 ± 3,71 anos. O lactato e a CPK apresentaram significância entre os momentos em todas as etapas avaliadas, porém as suplementações comparadas entre si não apresentaram diferença estatística. Não houve melhora da performance (p>0,05) com as utilizações de bicarbonato de sódio, beta alanina e suco de limão em ciclistas. Para os parâmetros avaliados, nenhum dos suplementos apresentou superioridade nas variáveis de tamponamento, dano muscular e performance no treinamento.
Some supplements exert buffering activity and have been recognized for their anaerobic contribution to high-intensity exercise, delaying peripheral muscle fatigue and thus enhancing sports performance. The aim of this study was to compare the ergogenic benefit in muscle buffering and damage of beta alanine, sodium bicarbonate and lemon juice supplements through the measurement of blood lactate and creatine phosphokinase (CPK) and on the performance of cyclists submitted to high intensity anaerobic exercise. Cross-sectional study, carried out in 4 stages, with male cyclists. Supplementation was 6 g beta alanine, 0.2 g/kg of sodium bicarbonate and 30 mL of lemon juice. Blood lactate and creatine phosphokinase enzyme were measured by the enzymatic and kinetic ultraviolet test method, respectively, in each of the steps. Performance corresponded to the maximum rotation per minute (RPM) of the Air Bike. Seven cyclists participated in the study, with a mean age of 31.14 ± 3.71 years. Lactate and CPK presented significance between the moments in all the evaluated stages, however the supplements compared to each other showed no statistical difference. There was no performance improvement (p>0.05) with the use of sodium bicarbonate, beta alanine and lemon juice in cyclists. For the parameters evaluated, none of the supplements showed superiority in the variables of buffering, muscle damage and training performance.
Assuntos
Humanos , Masculino , Adulto , Padrões de Referência , beta-Alanina , Bicarbonato de Sódio , Fadiga Muscular , Ácido Láctico , Creatina Quinase , Alanina , EnzimasRESUMO
The generation of amino acid homochirality under prebiotic atmosphere conditions is a relevant issue in the study of the origin of life. This research is based on the production of amino acids via Strecker synthesis and how it is adjusted to the Kondepudi-Nelson autocatalytic model. The spontaneous mirror symmetry breaking (SMSB) of the new Kondepudi-Nelson-Strecker model, subject to two modifications (with Limited Enantioselective and Cross Inhibition), and also their combination were studied using the stoichiometric network analysis (SNA). In the calculations, the values obtained from the literature for alanine were considered. A total production of alanine of 7.56 × 109 mol year-1 was determined under prebiotic atmosphere conditions and starting from that value, the reaction rates for the models studied were estimated. Only the model with cross inhibition or achiral dimer formation is driven by stochastic fluctuations during SMSB. The stochastic fluctuation was estimated for a value of 2.619 × 10-15 mol L-1. This perturbation was sufficient to trigger SMSB. Finally, the results of SMSB were used to calculate the entropy production for the cross inhibition model.
Assuntos
Aminoácidos , Modelos Químicos , Alanina , Aminoácidos/química , Atmosfera , Catálise , Estereoisomerismo , TermodinâmicaRESUMO
By December 2021, the COVID-19 caused approximately 6.1 million deaths around the world. Several vaccines have been approved, but there is still a need for non-prophylactic treatments for COVID-19. Remdesivir is an antiviral drug approved for emergency use against COVID-19 in several countries, but one of the first clinical trials was inconclusive about the mortality reduction, although the drug showed a reduction in the recovery time of hospitalized patients. Thus, the present investigation revisits the clinical evidence of using remdesivir for COVID-19 treatment, patent status, pharmacology and chemistry. We found 184 families of patents in the Cortellis database, and concerning the clinical evidence, we retrieved 14 systematic reviews with meta-analysis involving remdesivir as a treatment for COVID-19, discussing the reduction of adverse events, hospitalization days, mortality rate and the mechanical ventilation period.
Assuntos
Tratamento Farmacológico da COVID-19 , Monofosfato de Adenosina/efeitos adversos , Monofosfato de Adenosina/análogos & derivados , Alanina/análogos & derivados , Antivirais/efeitos adversos , Humanos , SARS-CoV-2RESUMO
Flood tolerance is crucial to the survival of tree species subject to long periods of flooding, such as those present in the Amazonian várzea. Tolerance can be mediated by adjustments of metabolism, physiology and morphology, reinforcing the need to investigate the physiological and biochemical mechanisms used by tropical tree species to survive this stress. Moreover, such mechanisms may vary between populations that are subjected to differences in the frequency of flooding events. Here, we aimed to identify the mechanisms used by two populations of the tropical tree Guazuma ulmifolia (Lam.) to tolerate flooding: an Amazonian population frequently exposed to flooding and a Cerrado population, adapted to a dry environment. Young plants were subjected to a flooding of the roots and lower stem for 32 days, followed by 17 days of recovery. Amazonian plants exhibited greater increases in shoot length and higher maximum photosynthetic rate (Amax) compared with non-flooded plants from 7 days of flooding onwards, whereas increased Amax occurred later in flooded Cerrado plants and was not accompanied by increased shoot length. Lactate accumulated in roots of Cerrado plants after 24 h flooding, together with transcripts coding for lactate dehydrogenase in roots of both Cerrado and Amazonian plants. After 7 days of flooding, lactate decreased and alcohol dehydrogenase activity increased transiently, together with concentrations of alanine, γ-aminobutyric acid and succinate, indicating activation of metabolic processes associated with low oxygen availability. Other amino acids also increased in flooded Cerrado plants, revealing more extensive metabolic changes than in Amazonian plants. Wetland and dryland populations of G. ulmifolia revealed the great capacity to tolerate flooding stress through a suite of alterations in photosynthetic gas exchange and metabolism. However, the integrated physiological, biochemical and molecular analyses realized here indicated that wetland plants acclimatized more efficiently with increased shoot elongation and more rapid restoration of normal metabolism.