RESUMO
We developed an arginine-responsive biosensor by integrating cascade enzymatic reactions into nanochannels functionalized with weak polyelectrolytes, which serve as "reactive signal amplifiers." This approach enhances device performance and broadens the detectable analyte range by generating high local analyte concentrations. The nanofluidic biosensor operates rapidly (<5 minutes) with a low detection limit of 3 µM.
Assuntos
Arginina , Técnicas Biossensoriais , Arginina/análise , Arginina/química , Arginina/metabolismo , Limite de Detecção , Técnicas Analíticas Microfluídicas/instrumentação , NanotecnologiaRESUMO
Leishmaniasis is a neglected tropical disease caused by parasites of the genus Leishmania and is responsible for more than 1 million new cases and 70,000 deaths annually worldwide. Treatment has high costs, toxicity, complex and long administration time, several adverse effects, and drug-resistant strains, therefore new therapies are urgently needed. Synthetic compounds have been highlighted in the medicinal chemistry field as a strong option for drug development against different diseases. Organic salts (OS) have multiple biological activities, including activity against protozoa such as Leishmania spp. This study aimed to investigate the in vitro leishmanicidal activity and death mechanisms of a thiohydantoin salt derived from l-arginine (ThS) against Leishmania amazonensis. We observed that ThS treatment inhibited promastigote proliferation, increased ROS production, phosphatidylserine exposure and plasma membrane permeabilization, loss of mitochondrial membrane potential, lipid body accumulation, autophagic vacuole formation, cell cycle alteration, and morphological and ultrastructural changes, showing parasites death. Additionally, ThS presents low cytotoxicity in murine macrophages (J774A.1), human monocytes (THP-1), and sheep erythrocytes. ThS in vitro cell treatment reduced the percentage of infected macrophages and the number of amastigotes per macrophage by increasing ROS production and reducing TNF-α levels. These results highlight the potential of ThS among thiohydantoins, mainly related to the arginine portion, as a leishmanicidal drug for future drug strategies for leishmaniasis treatment. Notably, in silico investigation of key targets from L. amazonensis, revealed that a ThS compound from the l-arginine amino acid strongly interacts with arginase (ARG) and TNF-α converting enzyme (TACE), suggesting its potential as a Leishmania inhibitor.
Assuntos
Arginina , Leishmania , Macrófagos , Simulação de Acoplamento Molecular , Espécies Reativas de Oxigênio , Animais , Arginina/farmacologia , Arginina/química , Arginina/metabolismo , Camundongos , Humanos , Leishmania/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/parasitologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Ovinos , Antiprotozoários/farmacologia , Antiprotozoários/química , Eritrócitos/efeitos dos fármacos , Eritrócitos/parasitologia , Eritrócitos/metabolismo , Linhagem Celular , Leishmania mexicana/efeitos dos fármacos , Leishmania mexicana/metabolismo , Células THP-1 , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The kallikrein-related peptidase KLK2 has restricted expression in the prostate luminal epithelium, and its protein target is unknown. The present work reports the hydrolytic activities of KLK2 on libraries of fluorescence resonance energy-transfer peptides from which the sequence SYRIF was the most susceptible substrate for KLK2. The sequence SYRIF is present at the extracellular N-terminal segment (58SYRIF63Q) of IL-10R2. KLK2 was fully active at pH 8.0-8.2, found only in prostate inflammatory conditions, and strongly activated by sodium citrate and glycosaminoglycans, the quantities and structures controlled by prostate cells. Bone-marrow-derived macrophages (BMDM) have IL-10R2 expressed on the cell surface, which is significantly reduced after KLK2 treatment, as determined by flow cytometry (FACS analysis). The IL-10 inhibition of the inflammatory response to LPS/IFN-γ in BMDM cells due to decreased nitric oxide, TNF-α, and IL-12 p40 levels is significantly reduced upon treatment of these cells with KLK2. Similar experiments with KLK3 did not show these effects. These observations indicate that KLK2 proteolytic activity plays a role in prostate inflammation and makes KLK2 a promising target for prostatitis treatment.
Assuntos
Calicreínas , Humanos , Masculino , Calicreínas/metabolismo , Calicreínas/química , Arginina/metabolismo , Arginina/química , Próstata/metabolismo , Próstata/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/efeitos dos fármacos , Animais , Camundongos , Peptídeos/química , Peptídeos/farmacologia , Peptídeos/metabolismo , Domínios Proteicos , Interleucina-10/metabolismo , Especificidade por SubstratoRESUMO
Arabidopsis (Arabidopsis thaliana) PROTEIN ARGININE METHYLTRANSFERASE5 (PRMT5) post-translationally modifies RNA-binding proteins by arginine (R) methylation. However, the impact of this modification on the regulation of RNA processing is largely unknown. We used the spliceosome component, SM-LIKE PROTEIN 4 (LSM4), as a paradigm to study the role of R-methylation in RNA processing. We found that LSM4 regulates alternative splicing (AS) of a suite of its in vivo targets identified here. The lsm4 and prmt5 mutants show a considerable overlap of genes with altered AS raising the possibility that splicing of those genes could be regulated by PRMT5-dependent LSM4 methylation. Indeed, LSM4 methylation impacts AS, particularly of genes linked with stress response. Wild-type LSM4 and an unmethylable version complement the lsm4-1 mutant, suggesting that methylation is not critical for growth in normal environments. However, LSM4 methylation increases with abscisic acid and is necessary for plants to grow under abiotic stress. Conversely, bacterial infection reduces LSM4 methylation, and plants that express unmethylable-LSM4 are more resistant to Pseudomonas than those expressing wild-type LSM4. This tolerance correlates with decreased intron retention of immune-response genes upon infection. Taken together, this provides direct evidence that R-methylation adjusts LSM4 function on pre-mRNA splicing in an antagonistic manner in response to biotic and abiotic stress.
Assuntos
Processamento Alternativo , Proteínas de Arabidopsis , Arabidopsis , Arginina , Regulação da Expressão Gênica de Plantas , Proteína-Arginina N-Metiltransferases , Estresse Fisiológico , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Processamento Alternativo/genética , Metilação , Proteína-Arginina N-Metiltransferases/metabolismo , Proteína-Arginina N-Metiltransferases/genética , Estresse Fisiológico/genética , Arginina/metabolismo , Ácido Abscísico/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/genética , Mutação/genéticaRESUMO
L-Arginine and chronic exercise reduce oxidative stress. However, it is unclear how they affect cardiomyocytes during cardiovascular disease (CVD) development. The aim of this research was to investigate the possible effects of L-arginine supplementation and aerobic training on systemic oxidative stress and their consequences on cardiomyocytes during cardiometabolic disease onset caused by excess fructose. Wistar rats were allocated into four groups: control (C), fructose (F, 10% fructose in water), fructose training (FT; moderate running, 50-70% of the maximal velocity), and fructose arginine (FA; 880 mg/kg/day). Fructose was given for two weeks and fructose plus treatments for the subsequent eight weeks. Body composition, blood glucose, insulin, lipid profile, lipid peroxidation, nitrite, metalloproteinase-2 (MMP-2) activity, left ventricle histological changes, microRNA-126, -195, and -146, eNOS, p-eNOS, and TNF-α expressions were analyzed. Higher abdominal fat mass, triacylglycerol level, and insulin level were observed in the F group, and both treatments reversed these alterations. Myocardial vascularization was impaired in fructose-fed groups, except in FT. Cardiomyocyte hypertrophy was observed in all fructose-fed groups. TNF-α levels were higher in fructose-fed groups than in the C group, and p-eNOS levels were higher in the FA than in the C and F groups. Lipid peroxidation was higher in the F group than in the FT and C groups. During CVD onset, moderate aerobic exercise reduced lipid peroxidation, and both training and L-arginine prevented metabolic changes caused by excessive fructose. Myocardial vascularization was impaired by fructose, and cardiomyocyte hypertrophy appeared to be influenced by pro-inflammatory and oxidative environments.
Assuntos
Doenças Cardiovasculares , MicroRNAs , Ratos , Animais , Doenças Cardiovasculares/metabolismo , Miócitos Cardíacos/metabolismo , Ratos Wistar , Fator de Necrose Tumoral alfa/farmacologia , Metaloproteinase 2 da Matriz/metabolismo , Óxido Nítrico Sintase/metabolismo , Estresse Oxidativo , Arginina/farmacologia , Arginina/metabolismo , Insulina , Frutose/metabolismo , Frutose/farmacologia , Suplementos Nutricionais , Hipertrofia/metabolismo , MicroRNAs/metabolismoRESUMO
The metabolism of the model microalgae Chlamydomonas reinhardtii under nitrogen deprivation is of special interest due to its resulting increment of triacylglycerols (TAGs), that can be applied in biotechnological applications. However, this same condition impairs cell growth, which may limit the microalgae's large applications. Several studies have identified significant physiological and molecular changes that occur during the transition from an abundant to a low or absent nitrogen supply, explaining in detail the differences in the proteome, metabolome and transcriptome of the cells that may be responsible for and responsive to this condition. However, there are still some intriguing questions that reside in the core of the regulation of these cellular responses that make this process even more interesting and complex. In this scenario, we reviewed the main metabolic pathways that are involved in the response, mining and exploring, through a reanalysis of omics data from previously published datasets, the commonalities among the responses and unraveling unexplained or non-explored mechanisms of the possible regulatory aspects of the response. Proteomics, metabolomics and transcriptomics data were reanalysed using a common strategy, and an in silico gene promoter motif analysis was performed. Together, these results identified and suggested a strong association between the metabolism of amino acids, especially arginine, glutamate and ornithine pathways to the production of TAGs, via the de novo synthesis of lipids. Furthermore, our analysis and data mining indicate that signalling cascades orchestrated with the indirect participation of phosphorylation, nitrosylation and peroxidation events may be essential to the process. The amino acid pathways and the amount of arginine and ornithine available in the cells, at least transiently during nitrogen deprivation, may be in the core of the post-transcriptional, metabolic regulation of this complex phenomenon. Their further exploration is important to the discovery of novel advances in the understanding of microalgae lipids' production.
Assuntos
Chlamydomonas reinhardtii , Chlamydomonas reinhardtii/genética , Arginina/metabolismo , Nitrogênio/metabolismo , Aminoácidos/metabolismo , Triglicerídeos/metabolismo , Jejum , Ornitina/metabolismoRESUMO
Venom-derived proteins and peptides have prevented neuronal cell loss, damage, and death in the study of neurodegenerative disorders. The cytoprotective effects of the peptide fraction (PF) from Bothrops jararaca snake venom were evaluated against oxidative stress changes in neuronal PC12 cells and astrocyte-like C6 cells. PC12 and C6 cells were pre-treated for 4 h with different concentrations of PF, and then H2O2 was added (0.5 mM in PC12 cells; 0.4 mM in C6 cells) and incubated for 20 h more. In PC12 cells, PF at 0.78 µg mL-1 increased viability (113.6 ± 6.3%) and metabolism (96.3 ± 10.3%) cell against H2O2-induced neurotoxicity (75.6 ± 5.8%; 66.5 ± 3.3%, respectively), reducing oxidative stress markers such as ROS generation, NO production, and arginase indirect activity through urea synthesis. Despite that, PF showed no cytoprotective effects in C6 cells, but potentiated the H2O2-induced damage at a concentration lower than 0.07 µg mL-1. Furthermore, the role of metabolites derived from L-arginine metabolism was verified in PF-mediated neuroprotection in PC12 cells, using specific inhibitors of two of the key enzymes in the L-arginine metabolic pathway: the α-Methyl-DL-aspartic acid (MDLA) to argininosuccinate synthetase (AsS), responsible for the recycling of L-citrulline to L-arginine; and, L-NΩ-Nitroarginine methyl ester (L-Name) to nitric oxide synthase (NOS), which catalyzes the synthesis of NO from L-arginine. The inhibition of AsS and NOS suppressed PF-mediated cytoprotection against oxidative stress, indicating that its mechanism is dependent on the production pathway of L-arginine metabolites such as NO and, more importantly, polyamines from ornithine metabolism, which are involved in the neuroprotection mechanism described in the literature. Overall, this work provides novel opportunities for evaluating whether the neuroprotective properties of PF shown in particular neuronal cells are sustained and for exploring potential drug development pathways for the treatment of neurodegenerative diseases.
Assuntos
Bothrops , Animais , Ratos , Arginina/metabolismo , Arginina/farmacologia , Astrócitos/metabolismo , Bothrops/metabolismo , Peróxido de Hidrogênio , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico Sintase/farmacologia , Estresse Oxidativo , Células PC12 , Peptídeos/farmacologia , Venenos de Serpentes/metabolismoRESUMO
Arginine methylation is catalysed by Protein Arginine Methyltransferases (PRMTs) and can affect how a target protein functions and how it interacts with other macromolecules, which in turn impacts on cell metabolism and gene expression control. Leishmania parasites express five different PRMTs, and although the presence of each individual PRMT is not essential per se, the imbalanced activity of these PRMTs can impact the virulence of Leishmania parasites in vitro and in vivo. Here we created a Leishmania major cell line overexpressing PRMT6 and show that similar to what was observed for the T. brucei homologous enzyme, L. major PRMT6 probably has a narrow substrate range. However, its overexpression notably impairs the infection in mice, with a mild reduction in the number of viable parasites in the lymph nodes. Our results indicate that arginine methylation by LmjPRMT6 plays a significant role in the adaptation of the parasite to the environment found in the mammalian host.
Assuntos
Leishmania major , Parasitos , Camundongos , Animais , Proteína-Arginina N-Metiltransferases/química , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo , Parasitos/metabolismo , Metilação , Arginina/metabolismo , MamíferosRESUMO
To evaluate the posttranslational arginylation of proteins in vivo, we describe a protocol for studying the 14C-Arg incorporation into proteins of cells in culture. The conditions determined for this particular modification contemplate both the biochemical requirements of the enzyme ATE1 and the adjustments that allowed the discrimination between posttranslational arginylation of proteins and de novo synthesis. These conditions are applicable for different cell lines or primary cultures, representing an optimal procedure for the identification and the validation of putative ATE1 substrates.
Assuntos
Aminoaciltransferases , Aminoaciltransferases/genética , Processamento de Proteína Pós-Traducional , Proteínas/metabolismo , Células Cultivadas , Linhagem Celular , Arginina/metabolismoRESUMO
Leishmania is a protozoan that causes leishmaniasis, a neglected tropical disease with clinical manifestations classified as cutaneous, mucocutaneous, and visceral leishmaniasis. In the infection context, the parasite can modulate macrophage gene expression affecting the microbicidal activity and immune response. The metabolism of L-arginine into polyamines putrescine, spermidine, and spermine reduces nitric oxide (NO) production, favoring Leishmania survival. Here, we investigate the effect of supplementation with L-arginine and polyamines in infection of murine BALB/c macrophages by L. amazonensis and in the transcriptional regulation of genes involved in arginine metabolism and proinflammatory response. We showed a reduction in the percentage of infected macrophages upon putrescine supplementation compared to L-arginine, spermidine, and spermine supplementation. Unexpectedly, deprivation of L-arginine increased nitric oxide synthase (Nos2) gene expression without changes in NO production. Putrescine supplementation increased transcript levels of polyamine metabolism-related genes Arg2, ornithine decarboxylase (Odc1), Spermidine synthase (SpdS), and Spermine synthase (SpmS), but reduced Arg1 in L. amazonensis infected macrophages, while spermidine and spermine promoted opposite effects. Putrescine increased Nos2 expression without leading to NO production, while L-arginine plus spermine led to NO production in uninfected macrophages, suggesting that polyamines can induce NO production. Besides, L-arginine supplementation reduced Il-1b during infection, and L-arginine or L-arginine plus putrescine increased Mcp1 at 24h of infection, suggesting that polyamines availability can interfere with cytokine/chemokine production. Our data showed that putrescine shifts L-arginine-metabolism related-genes on BALB/c macrophages and affects infection by L. amazonensis.
Assuntos
Leishmania , Leishmaniose , Animais , Camundongos , Putrescina/farmacologia , Putrescina/metabolismo , Espermidina/farmacologia , Espermidina/metabolismo , Espermina/metabolismo , Poliaminas/metabolismo , Leishmaniose/tratamento farmacológico , Ornitina Descarboxilase/genética , Ornitina Descarboxilase/metabolismo , Óxido Nítrico Sintase/metabolismo , Macrófagos/metabolismo , Arginina/farmacologia , Arginina/metabolismo , Suplementos NutricionaisRESUMO
Mucositis is defined as inflammatory and ulcerative lesions along of the gastrointestinal tract that leads to the imbalance of the intestinal microbiota. The use of compounds with action on the integrity of the intestinal epithelium and their microbiota may be a beneficial alternative for the prevention and/or treatment of mucositis. So, the aim of this study was to evaluate the effectiveness of the association of fructo-oligosaccharides (FOS) and arginine on intestinal damage in experimental mucositis. BALB/c mice were randomized into five groups: CTL (without mucositis + saline), MUC (mucositis + saline), MUC + FOS (mucositis + supplementation with FOS-1st until 10th day), MUC + ARG (mucositis + supplementation with arginine-1st until 10th day), and MUC + FOS + ARG (mucositis + supplementation with FOS and arginine-1st until 10th day). On the 7th day, mucositis was induced with an intraperitoneal injection of 300 mg/kg 5-fluorouracil (5-FU), and after 72 h, the animals were euthanized. The results showed that association of FOS and arginine reduced weight loss and oxidative stress (P < 0.05) and maintained intestinal permeability and histological score at physiological levels. The supplementation with FOS and arginine also increased the number of goblet cells, collagen area, and GPR41 and GPR43 gene expression (P < 0.05). Besides these, the association of FOS and arginine modulated intestinal microbiota, leading to an increase in the abundance of the genera Bacteroides, Anaerostipes, and Lactobacillus (P < 0.05) in relation to increased concentration of propionate and acetate. In conclusion, the present results show that the association of FOS and arginine could be important adjuvants in the prevention of intestinal mucositis probably due to modulated intestinal microbiota.
Assuntos
Microbioma Gastrointestinal , Mucosite , Camundongos , Animais , Mucosite/tratamento farmacológico , Mucosite/metabolismo , Mucosite/patologia , Arginina/metabolismo , Intestinos , Mucosa Intestinal/metabolismo , Fluoruracila , Oligossacarídeos/farmacologiaRESUMO
In the present study, we investigated whether magnesium sulphate activates the L-arginine/NO/cGMP pathway and elicits peripheral antinociception. The male Swiss mice paw pressure test was performed with hyperalgesia induced by intraplantar injection of prostaglandin E2. All drugs were administered locally into the right hind paw of animals. Magnesium sulphate (20, 40, 80 and 160 µg/paw) induced an antinociceptive effect. The dose of 80 µg/paw elicited a local antinociceptive effect that was antagonized by the non-selective NOS inhibitor, L-NOArg, and by the selective neuronal NOS inhibitor, L-NPA. The inhibitors, L-NIO and L-NIL, selectively inhibited endothelial and inducible NOS, respectively, but were ineffective regarding peripheral magnesium sulphate injection. The soluble guanylyl cyclase inhibitor, ODQ, blocked the action of magnesium sulphate, and the cGMP-phosphodiesterase inhibitor, zaprinast, enhanced the antinociceptive effects of intermediate dose of magnesium sulphate. Our results suggest that magnesium sulphate stimulates the NO/cGMP pathway via neuronal NO synthase to induce peripheral antinociceptive effects.
Assuntos
Dinoprostona , Sulfato de Magnésio , Analgésicos/farmacologia , Animais , Arginina/metabolismo , GMP Cíclico/metabolismo , Dinoprostona/efeitos adversos , Hiperalgesia/induzido quimicamente , Hiperalgesia/tratamento farmacológico , Hiperalgesia/metabolismo , Sulfato de Magnésio/farmacologia , Masculino , Camundongos , Óxido Nítrico , Nitroarginina , Inibidores de Fosfodiesterase/farmacologia , Guanilil Ciclase Solúvel/antagonistas & inibidoresRESUMO
The consumption of plant proteins is increasing worldwide. These proteins have an important role in human nutrition as well as in the technological properties of foods. Thus, there is a great interest in exploring new sources of plant proteins, such as macauba (Acrocomia aculeata), which is a promising tropical palm tree, native to Brazil, whose fruits are rich in oil, proteins and dietary fiber. Hence, the objective of this work was to obtain and evaluate the physico-chemical and techno-functional properties of the macauba kernel protein isolate (MKPI). Defatted macauba kernel flour was obtained and used to produce the MKPI by isoelectric precipitation. Then, the proximate composition, amino acid profile, and physico-chemical and techno-functional properties of the MKPI were determined. The MKPI stood out for its high protein content (94.9%) and high levels of arginine (16.21%) and glutamate (20.84%). The MKPI average isoelectric point was at pH 4.9 and its proteins showed low solubility in the pH range from 4.0 to 6.0. Moreover, the hydrophobicity of MKPI proteins was higher at pH 3.5 than at pH 7.0, and they had higher oil holding capacity (153.77%) than water holding capacity (97.29%). Regarding the MKPI emulsifying and gelling properties, emulsions with 0.5% and 1.0% of MKPI remained stable during storage and the minimum gelling concentration was 14%. Thus, the MKPI has a great potential to be produced and used by the food industry due to its nutritional and techno-functional properties.
Assuntos
Arecaceae , Aminoácidos/metabolismo , Arecaceae/química , Arginina/metabolismo , Fibras na Dieta/metabolismo , Glutamatos , Humanos , Proteínas de Plantas/metabolismo , Água/metabolismoRESUMO
Extracellular proteolytic enzymes are produced by a variety of pathogenic microorganisms, and contribute to host colonization by modulating virulence. Here, we present a first characterization of leptolysin, a Leptospira metalloprotease of the pappalysin family identified in a previous exoproteomic study. Comparative molecular analysis of leptolysin with two other pappalysins from prokaryotes, ulilysin and mirolysin, reveals similarities regarding calcium, zinc, and arginine -binding sites conservation within the catalytic domain, but also discloses peculiarities. Variations observed in the primary and tertiary structures may reflect differences in primary specificities. Purified recombinant leptolysin of L. interrogans was obtained as a ~50 kDa protein. The protease exhibited maximal activity at pH 8.0 and 37°C, and hydrolytic activity was observed in the presence of different salts with maximum efficiency in NaCl. Substrate specificity was assessed using a small number of FRET peptides, and showed a marked preference for arginine residues at the P1 position. L. interrogans leptolysin proteolytic activity on proteinaceous substrates such as proteoglycans and plasma fibronectin was also evaluated. All proteins tested were efficiently degraded over time, confirming the protease´s broad-spectrum activity in vitro. In addition, leptolysin induced morphological alterations on HK-2 cells, which may be partially attributed to extracellular matrix (ECM) degradation. Hemorrhagic foci were observed in the dorsal skin of mice intradermally injected with leptolysin, as a plausible consequence of ECM disarray and vascular endothelium glycocalyx damage. Assuming that leptospiral proteases play an important role in all stages of the infectious process, characterizing their functional properties, substrates and mechanisms of action is of great importance for therapeutic purposes.
Assuntos
Leptospira , Metaloproteases , Animais , Arginina/metabolismo , Leptospira/química , Leptospira/metabolismo , Leptospirose , Metaloproteases/metabolismo , Metaloproteases/farmacologia , Camundongos , Peptídeo Hidrolases/metabolismoRESUMO
In neurosecretion, allosteric communication between voltage sensors and Ca2+ binding in BK channels is crucially involved in damping excitatory stimuli. Nevertheless, the voltage-sensing mechanism of BK channels is still under debate. Here, based on gating current measurements, we demonstrate that two arginines in the transmembrane segment S4 (R210 and R213) function as the BK gating charges. Significantly, the energy landscape of the gating particles is electrostatically tuned by a network of salt bridges contained in the voltage sensor domain (VSD). Molecular dynamics simulations and proton transport experiments in the hyperpolarization-activated R210H mutant suggest that the electric field drops off within a narrow septum whose boundaries are defined by the gating charges. Unlike Kv channels, the charge movement in BK appears to be limited to a small displacement of the guanidinium moieties of R210 and R213, without significant movement of the S4.
Assuntos
Ativação do Canal Iônico , Canais de Potássio Ativados por Cálcio de Condutância Alta , Arginina/metabolismo , Ativação do Canal Iônico/genética , Simulação de Dinâmica Molecular , MutaçãoRESUMO
Knowledge about viral characteristics, mechanisms of entry into the host cell and multiplication/dissemination can help in the control and treatment of viral pathologies. Several nutritional factors linked to the host may favour viral multiplication and their control, may lead to new prophylactic alternatives and/or antiviral therapies. The objective of this review is to discuss the relationship between the amino acid L-lysine and the control of viral infections, aiming at a possible therapeutic property. This research used databases such as PubMed, Web of Science, Scielo, Medline and Google Scholar, as well as searching for references cited by journals. The time frame covered the period between 1964 and January 2022. The observed studies have shown that the usual antiviral therapies are not able to interfere with the viruses in their latent state; however, they can interfere with the adhesion and fusion of viral particles or the production of proteins, which play an important role in viral epidemiology and control, particularly in the initial moment and in reactivation. Lysine is an amino acid that can interfere mainly in the formation of capsid proteins and DNA by a competitive antagonism with amino acid arginine, which is an essential amino acid for some viruses, and also by promoting the increase of arginase, increasing the catabolism of arginine. Although there is evidence of the importance of L-lysine in viral control, more studies are needed, with a view to new antiviral therapies.
Assuntos
Lisina , Viroses , Aminoácidos/uso terapêutico , Antivirais/farmacologia , Antivirais/uso terapêutico , Arginase , Arginina/metabolismo , Arginina/uso terapêutico , Proteínas do Capsídeo , Humanos , Lisina/metabolismo , Lisina/uso terapêutico , Viroses/tratamento farmacológico , Viroses/prevenção & controleRESUMO
In trypanosomatids, regulation of gene expression occurs mainly at the posttranscriptional level, and RNA-binding proteins (RBPs) are key players in determining the fates of transcripts. RBPs are targets of protein arginine methyltransferases (PRMTs), which posttranslationally regulate the RNA-binding capacity and other RBP interactions by transferring methyl groups to arginine residues (R-methylation). Herein, we functionally characterized the five predicted PRMTs in Leishmania braziliensis by gene knockout and endogenous protein HA tagging using CRISPR/Cas9 gene editing. We report that R-methylation profiles vary among Leishmania species and across L. braziliensis lifecycle stages, with the peak PRMT expression occurring in promastigotes. A list of PRMT-interacting proteins was obtained in a single coimmunoprecipitation assay using HA-tagged PRMTs, suggesting a network of putative targets of PRMTs and cooperation between the R-methylation writers. Knockout of each L. braziliensis PRMT led to significant changes in global arginine methylation patterns without affecting cell viability. Deletion of either PRMT1 or PRMT3 disrupted most type I PRMT activity, resulting in a global increase in monomethyl arginine levels. Finally, we demonstrate that L. braziliensis PRMT1 and PRMT5 are required for efficient macrophage infection in vitro, and for axenic amastigote proliferation. The results indicate that R-methylation is modulated across lifecycle stages in L. braziliensis and show possible functional overlap and cooperation among the different PRMTs in targeting proteins. Overall, our data suggest important regulatory roles of these proteins throughout the L. braziliensis life cycle, showing that arginine methylation is important for parasite-host cell interactions.
Assuntos
Leishmania braziliensis , Proteína-Arginina N-Metiltransferases , Arginina/metabolismo , Leishmania braziliensis/genética , Macrófagos/metabolismo , Metilação , Proteína-Arginina N-Metiltransferases/química , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismoRESUMO
Arginine kinase from Trypanosoma cruzi (TcAK) catalyzes the interconversion of arginine and phosphoarginine to maintain the ATP/ADP cell balance, and is involved in the parasites' energetic homeostasis and stress responses. Using virtual screening approaches, some plant-derived polyphenolic pigments, such as anthocyanidins, were predicted to inhibit TcAK activity. Here, it was demonstrated that the anthocyanidin delphinidin showed a non-competitive inhibition mechanism of TcAK (Ki arginine = 1.32 µM and Ki ATP = 500 µM). Molecular docking simulations predicted that delphinidin occupies part of the ATP/ADP pocket, more specifically the one that binds the ribose phosphate, and molecular dynamics simulations confirmed the amino acids involved in binding. Delphinidin exerted trypanocidal activity over T. cruzi trypomastigotes with a calculated IC50 of 19.51 µM. Anthocyanidins are low-toxicity natural products which can be exploited for the development of trypanocidal drugs with less secondary effects than those currently used for the treatment of Chagas disease.
Assuntos
Antocianinas , Arginina Quinase , Doença de Chagas , Tripanossomicidas , Difosfato de Adenosina , Trifosfato de Adenosina , Antocianinas/farmacologia , Arginina/metabolismo , Arginina Quinase/antagonistas & inibidores , Doença de Chagas/tratamento farmacológico , Simulação de Acoplamento Molecular , Tripanossomicidas/química , Tripanossomicidas/farmacologia , Trypanosoma cruziRESUMO
Addition of arginine (Arg) from tRNA can cause major alterations of structure and function of protein substrates. This post-translational modification, termed protein arginylation, is mediated by the enzyme arginyl-tRNA-protein transferase 1 (Ate1). Arginylation plays essential roles in a variety of cellular processes, including cell migration, apoptosis, and cytoskeletal organization. Ate1 is associated with neuronal functions such as neurogenesis and neurite growth. However, the role of Ate1 in glial development, including oligodendrocyte (OL) differentiation and myelination processes in the central nervous system, is poorly understood. The present study revealed a peak in Ate1 protein expression during myelination process in primary cultured OLs. Post-transcriptional downregulation of Ate1 reduced the number of OL processes, and branching complexity, in vitro. We conditionally ablated Ate1 from OLs in mice using 2',3'-cyclic nucleotide 3'-phosphodiesterase-Cre promoter ("Ate1-KO" mice), to assess the role of Ate1 in OL function and axonal myelination in vivo. Immunostaining for OL differentiation markers revealed a notable reduction of mature OLs in corpus callosum of 14-day-old Ate1-KO, but no changes in spinal cord, in comparison with wild-type controls. Local proliferation of OL precursor cells was elevated in corpus callosum of 21-day-old Ate1-KO, but was unchanged in spinal cord. Five-month-old Ate1-KO displayed reductions of mature OL number and myelin thickness, with alterations of motor behaviors. Our findings, taken together, demonstrate that Ate1 helps maintain proper OL differentiation and myelination in corpus callosum in vivo, and that protein arginylation plays an essential role in developmental myelination.
Assuntos
Neurogênese , Oligodendroglia , Animais , Arginina/metabolismo , Sistema Nervoso Central/metabolismo , Camundongos , Bainha de Mielina/metabolismo , Oligodendroglia/metabolismo , Processamento de Proteína Pós-TraducionalRESUMO
Abstract Carbon tetrachloride (CCl4) represents an organic chemical that causes reactive oxygen species derived organ disturbances including male infertility. Melatonin (MLT) is a neurohormone with strong antioxidant capacity, involved in numerous physiological processes. In this study we evaluated the capability of MLT, administered in a single dose of 50 mg/kg, to preserve the testicular tissue function after an acute administration of CCl4 to rats. The disturbance in testicular tissue and the effects of MLT after CCl4 exposure were estimated using biochemical parameters that enabled us to determine the tissue (anti)oxidant status and the intensity of arginine/nitric oxide metabolism. Also, the serum levels of testosterone and the histopathological analysis of tissue gave us a better insight into the occurring changes. A significant diminution in tissue antioxidant defences, arginase activity and serum testosterone levels, followed by the increased production of nitric oxide and extensive lipid and protein oxidative damage, was observed in the CCl4-treated group. The application of MLT after the CCl4 caused changes, clearly visible at both biochemical and histological level, which could be interpreted mainly as a consequence of general antioxidant system stimulation and a radical scavenger. On the other hand, the application of MLT exerted a limited action on the nitric oxide signalling pathway.