Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24.742
Filtrar
1.
J Vis Exp ; (182)2022 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-35499346

RESUMO

Understanding protein homeostasis in vivo is key to knowing how the cells work in both physiological and disease conditions. The present protocol describes in vivo labeling and subsequent purification of newly synthesized proteins using an engineered mouse line to direct protein labeling to specific cellular populations. It is an inducible line by Cre recombinase expression of L274G-Methionine tRNA synthetase (MetRS*), enabling azidonorleucine (ANL) incorporation to the proteins, which otherwise will not occur. Using the method described here, it is possible to purify cell-type-specific proteomes labeled in vivo and detect subtle changes in protein content due to sample complexity reduction.


Assuntos
Aminoacil-tRNA Sintetases , Proteoma , Aminoacil-tRNA Sintetases/genética , Animais , Cromatografia de Afinidade , Metionina , Camundongos , Proteostase
2.
Anim Sci J ; 93(1): e13730, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35506328

RESUMO

This study aimed to investigate the effects of methionine hydroxyl analog chelated microminerals (MHA-M) replacing inorganic microminerals (ITMs) on the growth performance, fecal microminerals concentrations, immune function, and antioxidant status in growing-finishing pigs; 253 pigs (average 33.68 kg body weight) were randomly assigned to six treatments with six replicates each treatment: (1) ITM: a basal diet with Cu, Fe, Mn, and Zn from sulfates providing 20, 100, 40, and 60 mg/kg; (2-6): 1/5MHA-M, 2/5MHA-M, 3/5MHA-M, 4/5MHA-M, and MHA-M was replaced with 20%, 40%, 60%, 80%, and 100% MHA-M. Results showed that the average daily gain (ADG) in the 1/5MHA-M and 2/5MHA-M was greater than other groups in the whole period. Fecal Cu, Fe, Mn, and Zn concentrations had decreased as the intake of trace minerals decreases. The ITM group decreased the fecal Zn concentration on Days 35, 70, and 91, and Fe concentration on Day 70, and increased the Mn concentration on Day 70 compared with MHA-M group. Pigs fed 1/5MHA-M, 2/5MHA-M, and MHA-M had a higher immune function and antioxidant status in serum compared with ITM, 3/5MHA-M, and 4/5MHA-M on Day 35. In conclusion, treatment with 1/5MHA-M and 2/5MHA-M could reduce the excretion of fecal microminerals and improve the immune function and antioxidant capacity compared with the ITM group.


Assuntos
Antioxidantes , Oligoelementos , Ração Animal/análise , Animais , Imunidade , Metionina/farmacologia , Suínos
3.
Mol Biol (Mosk) ; 56(2): 296-319, 2022.
Artigo em Russo | MEDLINE | ID: mdl-35403621

RESUMO

Methyltransferases (MTases) play an important role in the functioning of living systems, catalyzing the methylation reactions of DNA, RNA, proteins, and small molecules, including endogenous compounds and drugs. Many human diseases are associated with disturbances in the functioning of these enzymes; therefore, the study of MTases is an urgent and important task. Most MTases use the cofactor S-adenosyl-L-methionine (SAM) as a methyl group donor. SAM analogs are widely applicable in the study of MTases: they are used in studies of the catalytic activity of these enzymes, in identification of substrates of new MTases, and for modification of the substrates or substrate linking to MTases. In this review, new synthetic analogs of SAM and the problems that can be solved with their usage are discussed.


Assuntos
Metiltransferases , S-Adenosilmetionina , DNA/química , Humanos , Metionina , Metiltransferases/genética , Metiltransferases/metabolismo , RNA , S-Adenosilmetionina/química , S-Adenosilmetionina/metabolismo
5.
Acc Chem Res ; 55(9): 1249-1261, 2022 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-35420432

RESUMO

The central dogma of molecular biology hinges on messenger RNA (mRNA), which presents a blueprint of the genetic information encoded in the DNA and serves as a template for translation into proteins. In addition to its fundamental importance in basic research, this class of biomolecules has recently become the first approved Covid vaccine, underscoring its utility in medical applications.Eukaryotic mRNA is heavily processed, including the 5' cap as the primary hallmark. This 5' cap protects mRNA from degradation by exoribonucleases but also interacts specifically with several proteins and enzymes to ensure mRNA turnover and processing, like splicing, export from the nucleus to the cytoplasm, and initiation of translation. The absence of a 5' cap leads to a strong immune response, and the methylation status contributes to distinguishing self from non-self RNA.Non-natural modifications of the 5' cap provide an avenue to label mRNAs and make them accessible to analyses, which is important to study their cellular localization, trafficking, and binding partners. They bear potential to engineer mRNAs, e.g., more stable or immunogenic mRNAs that are still translated, by impacting select interactions in a distinct manner. The modification of the 5' cap itself is powerful as it can be applied to make long mRNAs (∼1000 nt, not directly accessible by solid-phase synthesis) by in vitro transcription.This Account describes our contribution to the field of chemo-enzymatic modification of mRNA at the 5' cap. Our approach relies on RNA methyltransferases (MTases) with promiscuous activity on analogues of their natural cosubstrate S-adenosyl-L-methionine (AdoMet). We will describe how RNA MTases in combination with non-natural cosubstrates provide access to site-specific modification of different positions of the 5' cap, namely, the N2 and N7 position of guanosine and the N6 position of adenosine as the transcription start nucleotide (TSN) and exemplify strategies to make long mRNAs with modified 5' caps.We will compare the chemical and enzymatic synthesis of the AdoMet analogues used for this purpose. We could overcome previous limitations in methionine adenosyltransferase (MAT) substrate scope by engineering variants (termed PC-MATs) with the ability to convert methionine analogues with benzylic and photocaging groups at the sulfonium ion.The final part of this Account will highlight applications of the modified mRNAs. Like in many chemo-enzymatic approaches, a versatile strategy is to install small functional groups enzymatically and use them as handles in subsequent bioorthogonal reactions. We showed fluorescent labeling of mRNAs via different types of click chemistry in vitro and in cells. In a second line of applications, we used the handles to make mRNAs amenable for analyses, most notably next-generation sequencing. In the case of extremely promiscuous enzymes, the direct installation of photo-cross-linking groups was successful also and provided a way to covalently bind protein-interaction partners. Finally, the non-natural modifications of mRNAs can also modulate the properties of mRNAs. Propargylation of Am as the transcription start nucleotide at its N6 position maintained the translation of mRNAs but increased their immunogenicity. The installation of photocaging groups provides a way to revert these effects and control interactions by light.


Assuntos
RNA Mensageiro , S-Adenosilmetionina , Vacinas contra COVID-19 , Humanos , Metionina , Metiltransferases/genética , Metiltransferases/metabolismo , Nucleotídeos , RNA , RNA Mensageiro/metabolismo , S-Adenosilmetionina/química
6.
Food Funct ; 13(9): 4941-4953, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35437549

RESUMO

Recently, the protective effects of a methionine-rich diet on hepatic oxidative stress and fibrosis have been suggested but not adequately studied. We, therefore, hypothesized that L-methionine supplementation would ameliorate the progression of hepatic injury in a diet-induced non-alcoholic steatohepatitis (NASH) model and aimed to investigate the underlying mechanism. NASH was developed in male Sprague Dawley rats by feeding them with a high-fat-fructose diet (HFFrD) for 10 weeks. The results demonstrated that L-methionine supplementation to NASH rats for 16 weeks improved the glycemic, lipid, and liver function profiles in NASH rats. Histological analysis of liver tissue revealed a remarkable improvement in the three classical lesions of NASH: steatosis, inflammation, and ballooning. Besides, L-methionine supplementation ameliorated the HFFrD-induced enhanced lipogenesis and lipid peroxidation. An anti-inflammatory effect of L-methionine was also observed through the inhibition of the release of proinflammatory cytokines. Furthermore, the hepatic SIRT1/AMPK signaling pathway was associated with the beneficial effects of L-methionine. This study demonstrates that L-methionine supplementation in HFFrD-fed rats improves their liver pathology via regulation of lipogenesis, inflammation, and the SIRT1/AMPK pathway, thus encouraging its clinical evaluation for the treatment of NASH.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Dieta Hiperlipídica/efeitos adversos , Suplementos Nutricionais , Modelos Animais de Doenças , Fibrose , Frutose/metabolismo , Inflamação/metabolismo , Metabolismo dos Lipídeos , Fígado/metabolismo , Masculino , Metionina/metabolismo , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Ratos , Ratos Sprague-Dawley , Sirtuína 1/genética , Sirtuína 1/metabolismo
7.
Langmuir ; 38(18): 5865-5873, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35442695

RESUMO

The conventional key steps for seed-mediated growth of noble metal nanostructures involve classical and nonclassical nucleation. Furthermore, the surface of the seed catalytically enhances the secondary nucleation involving Au+ to Au0 reduction, thus providing in-plane growth of the seed. In contrast to this well-established growth mechanism, herein, we report the unique case of a methionine (Met)-controlled seed-mediated growth reaction, which rather proceeds via impeding secondary nucleation in the presence of citrate-stabilized gold nanoparticles (AuNPs). The interaction between the freshly generated Au+ and the thioether group of Met in the medium restricts the secondary nucleation process of further seed-catalyzed Au+ reduction to Au0. This incomplete conversion of Au+, as confirmed by X-ray photoelectron spectroscopy, results in a significant enhancement of the zeta (ζ) potential even at low Met concentrations. Nucleation of in situ generated small-sized particles (nAuNPs) takes place on the parent seed surface followed by their segregation from the seed. The self-assembly process of these nAuNPs arises from the aurophilic interaction among the Au+. Furthermore, the time-dependent growth of smaller particles to larger-sized particles through assembly and merging within the same self-assembly validates the nonclassical growth. This strategy has been successfully extended toward the seed-mediated growth reaction of AuNPs in the presence of three bio-inspired decameric peptides having varying numbers of Met residues. The study confirms the nucleation strategy even in the presence of a single Met residue in the peptide and also the self-assembly of nucleated particles with increasing Met residues within the peptide.


Assuntos
Nanopartículas Metálicas , Nanoestruturas , Ouro/química , Humanos , Nanopartículas Metálicas/química , Metionina , Nanoestruturas/química , Peptídeos
8.
Biomolecules ; 12(4)2022 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-35454145

RESUMO

Unlike its shorter analog, cysteine, and its methylated derivative, methionine, homocysteine is not today a proteinogenic amino acid. However, this thiol containing amino acid is capable of forming an activated species intramolecularly. Its thiolactone could have made it an interesting molecular building block at the origin of life on Earth. Here we study the cyclization of homocysteine in water and show theoretically and experimentally that in an acidic medium the proportion of thiolactone is significant. This thiolactone easily reacts with amino acids to form dipeptides. We envision that these reactions may help interpret why a methionine residue is introduced at the start of all protein synthesis.


Assuntos
Homocisteína , Peptídeos , Cisteína/metabolismo , Metionina/metabolismo , Compostos de Sulfidrila
9.
Cancer Genomics Proteomics ; 19(3): 299-304, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35430564

RESUMO

BACKGROUND/AIM: Methionine addiction is a fundamental and general hallmark of cancer cells, which require exogenous methionine, despite large amounts of methionine synthesized endogenously. 5-Methylthioadenosine phosphorylase (MTAP) plays a principal role as an enzyme in the methionine-salvage pathway, which produces methionine and adenine from methylthioadenosine and is deleted in 27.5% to 37.5% of osteosarcoma patients. MATERIALS AND METHODS: Human osteosarcoma cell lines U2OS, SaOS2, MNNG/HOS (HOS) and 143B, were used. The MTAP gene was knocked out in U2OS with CRISPR/Cas9. 143B and HOS have an MTAP deletion and SaOS2 is positive for MTAP. MTAP was determined by western blotting. The four cell lines were compared for sensitivity to recombinant methioninase (rMETase). RESULTS: MTAP-deleted osteosarcoma cell lines MNNG/HOS and 143B were significantly more sensitive to rMETase than MTAP-positive osteosarcoma cell lines U2OS and SaOS2. In addition, MTAP knock-out U2OS cells were more sensitive to rMETase than the parental MTAP-positive U2OS cells. CONCLUSION: The present results demonstrated that the absence of MTAP sensitizes osteosarcoma cells to methionine restriction by rMETase, a promising clinical strategy.


Assuntos
Neoplasias Ósseas , Metionina , Osteossarcoma , Purina-Núcleosídeo Fosforilase , Neoplasias Ósseas/genética , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/terapia , Liases de Carbono-Enxofre/genética , Liases de Carbono-Enxofre/metabolismo , Linhagem Celular Tumoral , Humanos , Metionina/deficiência , Metionina/metabolismo , Metionina/farmacologia , Metilnitronitrosoguanidina , Osteossarcoma/genética , Osteossarcoma/metabolismo , Osteossarcoma/terapia , Purina-Núcleosídeo Fosforilase/deficiência , Purina-Núcleosídeo Fosforilase/genética , Purina-Núcleosídeo Fosforilase/metabolismo , Proteínas Recombinantes/farmacologia
10.
Sci Rep ; 12(1): 6398, 2022 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-35430611

RESUMO

Dysregulation of nicotinamide adenine dinucleotide (NAD +) metabolism contributes to the initiation and progression of age-associated diseases, including chronic kidney disease (CKD). Nicotinamide N-methyltransferase (NNMT), a nicotinamide (NAM) metabolizing enzyme, regulates both NAD + and methionine metabolism. Although NNMT is expressed abundantly in the kidney, its role in CKD and renal fibrosis remains unclear. We generated NNMT-deficient mice and a unilateral ureter obstruction (UUO) model and conducted two clinical studies on human CKD to investigate the role of NNMT in CKD and fibrosis. In UUO, renal NNMT expression and the degraded metabolites of NAM increased, while NAD + and NAD + precursors decreased. NNMT deficiency ameliorated renal fibrosis; mechanistically, it (1) increased the DNA methylation of connective tissue growth factor (CTGF), and (2) improved renal inflammation by increasing renal NAD + and Sirt1 and decreasing NF-κB acetylation. In humans, along with CKD progression, a trend toward a decrease in serum NAD + precursors was observed, while the final NAD + metabolites were accumulated, and the level of eGFR was an independent variable for serum NAM. In addition, NNMT was highly expressed in fibrotic areas of human kidney tissues. In conclusion, increased renal NNMT expression induces NAD + and methionine metabolism perturbation and contributes to renal fibrosis.


Assuntos
NAD , Nicotinamida N-Metiltransferase , Insuficiência Renal Crônica , Obstrução Ureteral , Animais , Feminino , Fibrose , Humanos , Masculino , Metionina , Camundongos , NAD/metabolismo , Niacinamida/metabolismo , Nicotinamida N-Metiltransferase/genética , Nicotinamida N-Metiltransferase/metabolismo , Insuficiência Renal Crônica/genética , Insuficiência Renal Crônica/metabolismo , Obstrução Ureteral/genética , Obstrução Ureteral/metabolismo
11.
Anticancer Res ; 42(5): 2567-2572, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35489727

RESUMO

BACKGROUND: Pancreatic cancer is one of the most recalcitrant cancers, and more effective therapy is needed. Pre-clinical studies have shown that patient-derived orthotopic xenograft (PDOX) mouse models of pancreatic cancer are effectively treated with oral recombinant methioninase (o-rMETase). CASE REPORT: A 62-year-old woman diagnosed with stage IV pancreatic cancer was treated with the combination of 5-fluorouracil/leucovorin, irinotecan, and oxaliplatinum (FOLFIRINOX) every two weeks and o-rMETase twice a day as a supplement. The patient was also on a low-methionine diet. Disease progression was monitored by CA19-9 and computed tomography. The patient initially responded to FOLFIRINOX, shown by a great reduction in CA19-9 levels, with tumor shrinkage shown by computed tomography. The patient began taking o-rMETase and went on a low-methionine diet one year after diagnosis which she has maintained without side effects for 7 months. The patient's CA19-9 level and tumor size remain stable 19 months after diagnosis. The patient is alive and has maintained a high performance status. Historical data show that less than 5% of stage IV pancreatic-cancer patients on FOLFIRINOX have stable disease 1.5 years after diagnosis. CONCLUSION: The combination of o-rMETase and FOLFIRINOX may be synergistic in stage IV pancreatic cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias Pancreáticas , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Antígeno CA-19-9 , Liases de Carbono-Enxofre , Modelos Animais de Doenças , Feminino , Fluoruracila/uso terapêutico , Humanos , Irinotecano/uso terapêutico , Leucovorina/uso terapêutico , Metionina , Camundongos , Camundongos Nus , Oxaliplatina , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Nat Metab ; 4(4): 444-457, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35361955

RESUMO

Efferocytosis, the clearance of apoptotic cells (ACs) by macrophages, is critical for tissue resolution, with defects driving many diseases. Mechanisms of efferocytosis-mediated resolution are incompletely understood. Here, we show that AC-derived methionine regulates resolution through epigenetic repression of the extracellular signal-regulated kinase 1/2 (ERK1/2) phosphatase Dusp4. We focus on two key efferocytosis-induced pro-resolving mediators, prostaglandin E2 (PGE2) and transforming growth factor beta 1 (TGF-ß1), and show that efferocytosis induces prostaglandin-endoperoxide synthase 2/cyclooxygenase 2 (Ptgs2/COX2), leading to PGE2 synthesis and PGE2-mediated induction of TGF-ß1. ERK1/2 phosphorylation/activation by AC-activated CD36 is necessary for Ptgs2 induction, but this is insufficient owing to an ERK-DUSP4 negative feedback pathway that lowers phospho-ERK. However, subsequent AC engulfment and phagolysosomal degradation lead to Dusp4 repression, enabling enhanced p-ERK and induction of the Ptgs2-PGE2-TGF-ß1 pathway. Mechanistically, AC-derived methionine is converted to S-adenosylmethionine, which is used by DNA methyltransferase-3A (DNMT3A) to methylate Dusp4. Bone-marrow DNMT3A deletion in mice blocks COX2/PGE2, TGF-ß1, and resolution in sterile peritonitis, apoptosis-induced thymus injury and atherosclerosis. Knowledge of how macrophages use AC-cargo and epigenetics to induce resolution provides mechanistic insight and therapeutic options for diseases driven by impaired resolution.


Assuntos
/metabolismo , Metionina , Fator de Crescimento Transformador beta1 , Animais , Apoptose , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Macrófagos/metabolismo , Metionina/metabolismo , Camundongos , Prostaglandinas E/metabolismo , Fator de Crescimento Transformador beta1/metabolismo
13.
Int J Mol Sci ; 23(8)2022 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-35456998

RESUMO

Dysregulation of one-carbon metabolism affects a wide range of biological processes and is associated with a number of diseases, including cardiovascular disease, dementia, neural tube defects, and cancer. Accumulating evidence suggests that one-carbon metabolism plays an important role in COVID-19. The symptoms of long COVID-19 are similar to those presented by subjects suffering from vitamin B12 deficiency (pernicious anemia). The metabolism of a cell infected by the SARS-CoV-2 virus is reshaped to fulfill the need for massive viral RNA synthesis, which requires de novo purine biosynthesis involving folate and one-carbon metabolism. Many aspects of host sulfur amino acid metabolism, particularly glutathione metabolism underlying antioxidant defenses, are also taken over by the SARS-CoV-2 virus. The purpose of this review is to summarize recent findings related to one-carbon metabolism and sulfur metabolites in COVID-19 and discuss how they inform strategies to combat the disease.


Assuntos
COVID-19 , COVID-19/complicações , Carbono/metabolismo , Ácido Fólico/metabolismo , Homocisteína , Humanos , Metionina/metabolismo , SARS-CoV-2 , Vitamina B 12/metabolismo
14.
Clin Nucl Med ; 47(6): e428-e436, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35439178

RESUMO

PURPOSE: To evaluate the diagnostic potential of decision-tree model of diffusion kurtosis imaging (DKI) and 11C-methionine (11C-MET) PET, for the differentiation of radiotherapy (RT) injury from glioblastoma recurrence. METHODS: Eighty-six glioblastoma cases with suspected lesions after RT were retrospectively enrolled. Based on histopathology or follow-up, 48 patients were diagnosed with local glioblastoma recurrence, and 38 patients had RT injury between April 2014 and December 2019. All the patients underwent PET/MRI examinations. Multiple parameters were derived based on the ratio of tumor to normal control (TNR), including SUVmax and SUVmean, mean value of kurtosis and diffusivity (MK, MD) from DKI, and histogram parameters. The diagnostic models were established by decision trees. Receiver operating characteristic analysis was used for evaluating the diagnostic accuracy of each independent parameter and all the diagnostic models. RESULTS: The intercluster correlations of DKI, PET, and texture parameters were relatively weak, whereas the intracluster correlations were strong. Compared with models of DKI alone (sensitivity =1.00, specificity = 0.70, area under the curve [AUC] = 0.85) and PET alone (sensitivity = 0.83, specificity = 0.90, AUC = 0.89), the combined model demonstrated the best diagnostic accuracy (sensitivity = 1.00, specificity = 0.90, AUC = 0.95). CONCLUSIONS: Diffusion kurtosis imaging, 11C-MET PET, and histogram parameters provide complementary information about tissue. The decision-tree model combined with these parameters has the potential to further increase diagnostic accuracy for the discrimination between RT injury and glioblastoma recurrence over the standard Response Assessment in Neuro-Oncology criteria. 11C-MET PET/MRI may thus contribute to the management of glioblastoma patients with suspected lesions after RT.


Assuntos
Glioblastoma , Lesões por Radiação , Radioisótopos de Carbono , Imagem de Difusão por Ressonância Magnética/métodos , Glioblastoma/diagnóstico por imagem , Glioblastoma/radioterapia , Humanos , Imageamento por Ressonância Magnética , Metionina , Tomografia por Emissão de Pósitrons , Estudos Retrospectivos , Sensibilidade e Especificidade
15.
Bioengineered ; 13(4): 10811-10826, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35485140

RESUMO

The prevalence of nonalcoholic steatohepatitis (NASH), characterized by fatty liver, oxidative injury, and inflammation, has considerably increased in the recent years. Due to the complexity of NASH pathogenesis, compounds which can target different mechanisms and stages of NASH development are required. A robust screening model with translational capability is also required to develop therapies targeting NASH. In this study, we used HepG2 spheroids and rat primary hepatocytes to evaluate the potency of Livogrit, a tri-herbal Ayurvedic prescription medicine, as a hepatoprotective agent. NASH was developed in the cells via methionine and cystine-deficient cell culture media. Livogrit at concentration of 30 µg/mL was able to prevent NASH development by decreasing lipid accumulation, ROS production, AST release, NFκB activation and increasing lipolysis, GSH (reduced glutathione), and mitochondrial membrane potential. This study suggests that Livogrit might reduce the lipotoxicity-mediated ROS generation and subsequent production of inflammatory mediators as evident from the increased gene expression of FXR, FGF21, CHOP, CXCL5, and their normalization due to Livogrit treatment. Taken together, Livogrit showed the potential as a multimodal therapeutic formulation capable of attenuating the development of NASH. Our study highlights the potential of Livogrit as a hepatoprotective agent with translational possibilities.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Animais , Cistina/metabolismo , Hepatócitos/metabolismo , Humanos , Metionina/farmacologia , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/metabolismo , Estresse Oxidativo , Ratos , Espécies Reativas de Oxigênio/metabolismo
16.
Nutrients ; 14(7)2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35406035

RESUMO

Cockscomb hydrolysate was found to have neurite outgrowth-promoting activity in PC12 cells. To investigate the neurite outgrowth-promoting compounds derived from cockscomb hydrolysate, bioassay-guided purification was carried out. Purified active fractions were obtained by liquid-liquid partition, followed by column chromatography. High-performance liquid chromatography and proton nuclear magnetic resonance analyses of the purified active fractions clarified that the main compounds are threonine, alanine, valine, and methionine. By screening for 20 kinds of amino acids, it was shown that valine and methionine, but not threonine and alanine, have neurite outgrowth-promoting activity. The results of activity evaluation of the mixture of amino acids indicated that alanine enhanced the activity of valine and that the mixture of valine and methionine showed a higher ratio of neurite formation than did each of them alone. On the other hand, dipeptides formed by valine and methionine showed weak neurite outgrowth-promoting activity. A mixture of threonine, alanine, valine, and methionine at the same concentrations as those in cockscomb hydrolysate showed neurite outgrowth-promoting activity comparable to that of cockscomb hydrolysate although threonine, alanine, valine, and methionine alone did not show activity at their concentrations in cockscomb hydrolysate. Therefore, the strong neurite outgrowth-promoting activity of cockscomb hydrolysate was considered to be due to the synergistic effect of threonine, alanine, valine, and methionine.


Assuntos
Aminoácidos , Crescimento Neuronal , Alanina/metabolismo , Alanina/farmacologia , Aminoácidos/metabolismo , Animais , Metionina/metabolismo , Neuritos , Células PC12 , Ratos , Treonina/metabolismo , Valina/farmacologia
17.
Nutrients ; 14(7)2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35406088

RESUMO

Hyperhomocysteinemia (HHcy) is a methionine metabolism problem that causes a variety of inflammatory illnesses. Oxidative stress is among the processes thought to be involved in the pathophysiology of the damage produced by HHcy. HHcy is likely to involve the dysfunction of several organs, such as the kidney, liver, or gut, which are currently poorly understood. Nuts are regarded as an important part of a balanced diet since they include protein, good fatty acids, and critical nutrients. The aim of this work was to evaluate the anti-inflammatory and antioxidant effects of cashew nuts in HHcy induced by oral methionine administration for 30 days, and to examine the possible pathways involved. In HHcy rats, cashew nuts (100 mg/kg orally, daily) were able to counteract clinical biochemical changes, oxidative and nitrosative stress, reduced antioxidant enzyme levels, lipid peroxidation, proinflammatory cytokine release, histological tissue injuries, and apoptosis in the kidney, colon, and liver, possibly by the modulation of the antioxidant nuclear factor erythroid 2-related factor 2 NRF-2 and inflammatory nuclear factor NF-kB pathways. Thus, the results suggest that the consumption of cashew nuts may be beneficial for the treatment of inflammatory conditions associated with HHcy.


Assuntos
Anacardium , Hiper-Homocisteinemia , Animais , Antioxidantes/metabolismo , Hiper-Homocisteinemia/patologia , Inflamação , Metionina/metabolismo , Nozes/metabolismo , Estresse Oxidativo , Ratos
18.
Nutrients ; 14(7)2022 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35406143

RESUMO

Radiation therapy damages and depletes total bone marrow (BM) cellularity, compromising safety and limiting effective dosing. Aging also strains total BM and BM hematopoietic stem and progenitor cell (HSPC) renewal and function, resulting in multi-system defects. Interventions that preserve BM and BM HSPC homeostasis thus have potential clinical significance. Here, we report that 50% calorie restriction (CR) for 7-days or fasting for 3-days prior to irradiation improved mouse BM regrowth in the days and weeks post irradiation. Specifically, one week of 50% CR ameliorated loss of total BM cellularity post irradiation compared to ad libitum-fed controls. CR-mediated BM protection was abrogated by dietary sulfur amino acid (i.e., cysteine, methionine) supplementation or pharmacological inhibition of sulfur amino acid metabolizing and hydrogen sulfide (H2S) producing enzymes. Up to 2-fold increased proliferative capacity of ex vivo-irradiated BM isolated from food restricted mice relative to control mice indicates cell autonomy of the protective effect. Pretreatment with H2S in vitro was sufficient to preserve proliferative capacity by over 50% compared to non-treated cells in ex vivo-irradiated BM and BM HSPCs. The exogenous addition of H2S inhibited Ten eleven translocation 2 (TET2) activity in vitro, thus providing a potential mechanism of action. Short-term CR or fasting therefore offers BM radioprotection and promotes regrowth in part via altered sulfur amino acid metabolism and H2S generation, with translational implications for radiation treatment and aging.


Assuntos
Sulfeto de Hidrogênio , Lesões por Radiação , Animais , Medula Óssea/metabolismo , Restrição Calórica , Suplementos Nutricionais , Sulfeto de Hidrogênio/metabolismo , Sulfeto de Hidrogênio/farmacologia , Metionina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Radiação Ionizante
19.
Clin Sci (Lond) ; 136(9): 643-656, 2022 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-35438166

RESUMO

Annexin A1 (AnxA1) is an important effector in the resolution of inflammation which is involved in modulating hepatic inflammation in nonalcoholic steatohepatitis (NASH). In the present study, we have investigated the possible effects of treatment with AnxA1 for counteracting the progression of experimental NASH. NASH was induced in C57BL/6 mice by feeding methionine-choline deficient (MCD) or Western diets (WDs) and the animals were treated for 4-6 weeks with human recombinant AnxA1 (hrAnxA1; 1 µg, daily IP) or saline once NASH was established. In both experimental models, treatment with hrAnxA1 improved parenchymal injury and lobular inflammation without interfering with the extension of steatosis. Furthermore, administration of hrAnxA1 significantly attenuated the hepatic expression of α1-procollagen and TGF-ß1 and reduced collagen deposition, as evaluated by collagen Sirius Red staining. Flow cytometry and immunohistochemistry showed that hrAnxA1 did not affect the liver recruitment of macrophages, but strongly interfered with the formation of crown-like macrophage aggregates and reduced their capacity of producing pro-fibrogenic mediators like osteopontin (OPN) and galectin-3 (Gal-3). This effect was related to an interference with the acquisition of a specific macrophage phenotype characterized by the expression of the Triggering Receptor Expressed on Myeloid cells 2 (TREM-2), CD9 and CD206, previously associated with NASH evolution to cirrhosis. Collectively, these results indicate that, beside ameliorating hepatic inflammation, AnxA1 is specifically effective in preventing NASH-associated fibrosis by interfering with macrophage pro-fibrogenic features. Such a novel function of AnxA1 gives the rationale for the development of AnxA1 analogs for the therapeutic control of NASH evolution.


Assuntos
Anexina A1 , Hepatopatia Gordurosa não Alcoólica , Animais , Anexina A1/metabolismo , Modelos Animais de Doenças , Fibrose , Inflamação/patologia , Fígado/metabolismo , Cirrose Hepática/metabolismo , Metionina , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/metabolismo
20.
Mol Cells ; 45(3): 158-167, 2022 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-35253655

RESUMO

Ubiquitin (Ub) is post-translationally modified by Ub itself or Ub-like proteins, phosphorylation, and acetylation, among others, which elicits a variety of Ub topologies and cellular functions. However, N-terminal (Nt) modifications of Ub remain unknown, except the linear head-to-tail ubiquitylation via Nt-Met. Here, using the yeast Saccharomyces cerevisiae and an Nt-arginylated Ub-specific antibody, we found that the detectable level of Ub undergoes Nt-Met excision, Nt-deamination, and Nt-arginylation. The resulting Nt-arginylated Ub and its conjugated proteins are upregulated in the stationary-growth phase or by oxidative stress. We further proved the existence of Nt-arginylated Ub in vivo and identified Nt-arginylated Ub-protein conjugates using stable isotope labeling by amino acids in cell culture (SILAC)-based tandem mass spectrometry. In silico structural modeling of Nt-arginylated Ub predicted that Nt-Arg flexibly protrudes from the surface of the Ub, thereby most likely providing a docking site for the factors that recognize it. Collectively, these results reveal unprecedented Nt-arginylated Ub and the pathway by which it is produced, which greatly expands the known complexity of the Ub code.


Assuntos
Metionina , Processamento de Proteína Pós-Traducional , Saccharomyces cerevisiae/genética , Ubiquitina , Arginina/química , Desaminação , Metionina/química , Ubiquitina/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...