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1.
Biomed Res Int ; 2022: 9548316, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35686233

RESUMO

Noise-induced hearing loss (NIHL) has always been an important occupational hazard, but the exact etiopathogenesis underlying NIHL remains unclear. Herein, we aimed to find metabolic biomarkers involved in the development of NIHL based on a mouse model using a gas chromatography coupled with mass spectrometry (GC-MS) metabolomics technique. We showed that the auditory brainstem response (ABR) thresholds at the frequencies of 4, 8, 12, 16, 24, and 32 kHz were all significantly elevated in the noise-exposed mice. Noise could cause outer hair cell (OHC) loss in the base of the cochlea. A total of 17 differential metabolites and 9 metabolic pathways were significantly affected following noise exposure. Spermidine acting as an autophagy modulator was found to be 2.85-fold higher in the noise-exposed group than in the control group and involved in ß-alanine metabolism and arginine and proline metabolism pathways. Additionally, we demonstrated that LC3B and Beclin1 were expressed in the spiral ganglion neurons (SGNs), and their mRNA levels were increased after noise. We showed that SOD activity was significantly decreased in the cochlea of noise-exposed mice. Further experiments suggested that SOD1 and SOD2 proteins in the SGNs were all decreased following noise exposure. The upregulation of spermidine may induce LC3B- and Beclin1-mediated autophagy in the cochlear hair cells (HCs) through ß-alanine metabolism and arginine and proline metabolism and be involved in the NIHL. ROS-mediated oxidative damage may be a pivotal molecular mechanism of NIHL. Taken together, spermidine can be regarded as an important metabolic marker for the diagnosis of NIHL.


Assuntos
Perda Auditiva Provocada por Ruído , Animais , Arginina/metabolismo , Limiar Auditivo , Proteína Beclina-1/metabolismo , Cóclea/metabolismo , Potenciais Evocados Auditivos do Tronco Encefálico , Células Ciliadas Auditivas Externas/patologia , Perda Auditiva Provocada por Ruído/etiologia , Metabolômica , Camundongos , Prolina/metabolismo , Espermidina , beta-Alanina
2.
Cells ; 11(11)2022 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-35681491

RESUMO

Abiotic stresses profoundly affect plant growth and development and limit crop productivity. Pre-mRNA splicing is a major form of gene regulation that helps plants cope with various stresses. Serine/arginine (SR)-rich splicing factors play a key role in pre-mRNA splicing to regulate different biological processes under stress conditions. Alternative splicing (AS) of SR transcripts and other transcripts of stress-responsive genes generates multiple splice isoforms that contribute to protein diversity, modulate gene expression, and affect plant stress tolerance. Here, we investigated the function of the plant-specific SR protein RS33 in regulating pre-mRNA splicing and abiotic stress responses in rice. The loss-of-function mutant rs33 showed increased sensitivity to salt and low-temperature stresses. Genome-wide analyses of gene expression and splicing in wild-type and rs33 seedlings subjected to these stresses identified multiple splice isoforms of stress-responsive genes whose AS are regulated by RS33. The number of RS33-regulated genes was much higher under low-temperature stress than under salt stress. Our results suggest that the plant-specific splicing factor RS33 plays a crucial role during plant responses to abiotic stresses.


Assuntos
Oryza , Arginina/genética , Estudo de Associação Genômica Ampla , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas/metabolismo , Isoformas de Proteínas/metabolismo , Precursores de RNA/genética , Precursores de RNA/metabolismo , Fatores de Processamento de RNA/genética , Serina/genética , Estresse Fisiológico/genética
3.
Int J Mol Sci ; 23(11)2022 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-35682672

RESUMO

Two short arginine-containing tripeptides, H-Arg-Arg-Arg-OH (TP1) and Ac-Arg-Arg-Arg-NH2 (TP2), have been shown by the patch-clamp method to modulate the NaV1.8 channels of DRG primary sensory neurons, which are responsible for the generation of nociceptive signals. Conformational analysis of the tripeptides indicates that the key role in the ligand-receptor binding of TP1 and TP2 to the NaV1.8 channel is played by two positively charged guanidinium groups of the arginine side chains located at the characteristic distance of ~9 Å from each other. The tripeptide effect on the NaV1.8 channel activation gating device has been retained when the N- and C-terminal groups of TP1 were structurally modified to TP2 to protect the attacking peptide from proteolytic cleavage by exopeptidases during its delivery to the molecular target, the NaV1.8 channel. As demonstrated by the organotypic tissue culture method, the agents do not affect the DRG neurite growth, which makes it possible to expect the absence of adverse side effects at the tissue level upon administration of TP1 and TP2. The data obtained indicate that both tripeptides can have great therapeutic potential as novel analgesic medicinal substances.


Assuntos
Arginina , Gânglios Espinais , Analgésicos/farmacologia , Gânglios Espinais/fisiologia , Ligantes , Canal de Sódio Disparado por Voltagem NAV1.7 , Bloqueadores dos Canais de Sódio , Canais de Sódio
4.
Int J Mol Sci ; 23(11)2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35682712

RESUMO

Altered arginine metabolism (including the polyamine system) has recently been implicated in the pathogenesis of tauopathies, characterised by hyperphosphorylated and aggregated microtubule-associated protein tau (MAPT) accumulation in the brain. The present study, for the first time, systematically determined the time-course of arginine metabolism changes in the MAPT P301S (PS19) mouse brain at 2, 4, 6, 8 and 12 months of age. The polyamines putrescine, spermidine and spermine are critically involved in microtubule assembly and stabilization. This study, therefore, further investigated how polyamine biosynthetic and catabolic enzymes changed in PS19 mice. There were general age-dependent increases of L-arginine, L-ornithine, putrescine and spermidine in the PS19 brain (particularly in the hippocampus and parahippocampal region). While this profile change clearly indicates a shift of arginine metabolism to favor polyamine production (a polyamine stress response), spermine levels were decreased or unchanged due to the upregulation of polyamine retro-conversion pathways. Our results further implicate altered arginine metabolism (particularly the polyamine system) in the pathogenesis of tauopathies. Given the role of the polyamines in microtubule assembly and stabilization, future research is required to understand the functional significance of the polyamine stress response and explore the preventive and/or therapeutic opportunities for tauopathies by targeting the polyamine system.


Assuntos
Poliaminas , Tauopatias , Animais , Arginina/metabolismo , Encéfalo/metabolismo , Camundongos , Poliaminas/metabolismo , Putrescina/metabolismo , Espermidina , Espermina
5.
RNA Biol ; 19(1): 811-818, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35678613

RESUMO

As the only oxygenic phototrophs among prokaryotes, cyanobacteria employ intricate mechanisms to regulate common metabolic pathways. These mechanisms include small protein inhibitors exerting their function by protein-protein interaction with key metabolic enzymes and regulatory small RNAs (sRNAs). Here we show that the sRNA NsiR4, which is highly expressed under nitrogen limiting conditions, interacts with the mRNA of the recently described small protein PirA in the model strain Synechocystis sp. PCC 6803. In particular, NsiR4 targets the pirA 5'UTR close to the ribosome binding site. Heterologous reporter assays confirmed that this interaction interferes with pirA translation. PirA negatively impacts arginine synthesis under ammonium excess by competing with the central carbon/nitrogen regulator PII that binds to and thereby activates the key enzyme of arginine synthesis, N-acetyl-L-glutamate-kinase (NAGK). Consistently, ectopic nsiR4 expression in Synechocystis resulted in lowered PirA accumulation in response to ammonium upshifts, which also affected intracellular arginine pools. As NsiR4 and PirA are inversely regulated by the global nitrogen transcriptional regulator NtcA, this regulatory axis enables fine tuning of arginine synthesis and conveys additional metabolic flexibility under highly fluctuating nitrogen regimes. Pairs of small protein inhibitors and of sRNAs that control the abundance of these enzyme effectors at the post-transcriptional level appear as fundamental building blocks in the regulation of primary metabolism in cyanobacteria.


Assuntos
Compostos de Amônio , Synechocystis , Compostos de Amônio/metabolismo , Arginina/metabolismo , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Nitrogênio , Synechocystis/genética
6.
Metabolomics ; 18(6): 38, 2022 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-35687195

RESUMO

Functional gastrointestinal disorders (FGID) such as functional dyspepsia (FD) and irritable bowel syndrome (IBS) are highly prevalent and debilitating attributed to altered gut function and gut-brain interactions. FGID can be reliably diagnosed based upon the symptom pattern; but in the clinical setting FD or IBS a frequent diagnoses of exclusion after relevant structural causes of symptoms have been ruled out by appropriate testing. Thus far, there is no established biomarker for FGIDs. To address this limitation, we utilised multi-omics and chemometrics integration to characterise the blood plasma biochemistry in patients with IBS, FD, an overlap of FD/IBS, and controls using liquid chromatography-mass spectrometry (LC-MS) techniques.Cholesterol metabolism products Cholest-5,24-dien-3ß-ol, 3-O-ß-D-glucopyranoside, energy pathway metabolites, immunoglobulin-γ2 and immunoglobulin-κ, and carbonic anhydrase-1 proteins were particularly elevated in IBS. Furthermore, arginine and proline metabolisms, thyroid hormone synthesis, ferroptosis and, complementary and coagulation cascades were particularly upregulated in patients with IBS. Cer(d18:1/26:1(17Z)) and PI(14:0/22:1(11Z)) lipids were elevated in FD and FD-IBS but were depleted in IBS. Markers of central carbon metabolism and lipidome profiles allowed better discrimination and model predictability than metaproteome profile in healthy and FGID conditions.Overall, the multi-omics integration allowed the discrimination of healthy controls and FGID patients. It also effectively differentiated the biochemistry of FGID subtypes including FD, IBS and FD-IBS co-occurrence. This study points towards the possibility of multi-omics integration for rapid and high throughput analysis of plasma samples to support clinicians screen and diagnose patients with suspected FGIDs.


Assuntos
Dispepsia , Gastroenteropatias , Síndrome do Intestino Irritável , Arginina , Dispepsia/diagnóstico , Dispepsia/etiologia , Gastroenteropatias/complicações , Gastroenteropatias/diagnóstico , Humanos , Síndrome do Intestino Irritável/diagnóstico , Lipídeos , Metabolômica , Plasma , Prolina
7.
Pak J Pharm Sci ; 35(2(Special)): 635-640, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35668564

RESUMO

Present study aimed to explore the antihypertensive potential of bioactive peptides isolated from Brassica napus protein as inhibitor of angiotensin converting enzyme. Protein was extracted and assessed for antihypertensive potential. The extracted protein showed 72% antihypertensive activity/potential with IC50 value of 24±5.60µg/mL. Thirty-one fractions of peptides were isolated by hydrolyzing protein at different time intervals, pH, temperature and enzyme/substrate ratio. The antihypertensive potential of all isolated fractions was measured. It was found that only one peptide fraction exhibited significantly high (75%) antihypertensive potential. This hydrolyzed fraction was characterized through Liquid-Chromatography-Electrospray-Ionization-Mass-Spectrometry (LC-ESI-MS/MS). Eleven bioactive peptides were identified in hydrolyzate of Brassica napus which include Serine-Threonine, Methionine-Valine, Methionine-Leucine, Glutamine-Phenylalanine, Alanine-Threonine-Phenylalanine, Alanine-Leucine-Proline-Glycine, Valine-Alanine-Phenylalanine-Glycine, Aspartic acid-Proline-Methionine-Glutamine, Valine-Glutamine-Cysteine-Tyrosine, Methionine-Cysteine-Tyrosine-Tyrosine-Phenylalanine and Alanine-Leucine-Leucine-Alanine-Cysteine-Proline-Alanine. The current study showed that Brassica napus is an important food, having high amount of bioactive peptides with high antihypertensive potential, can control blood pressure very efficiently.


Assuntos
Anti-Hipertensivos , Brassica napus , Alanina , Angiotensinas , Anti-Hipertensivos/farmacologia , Arginina , Cisteína , Glutamina , Glicina , Histidina , Isoleucina , Leucina , Lisina , Metionina , Peptídeos/farmacologia , Peptidil Dipeptidase A , Fenilalanina , Prolina , Espectrometria de Massas em Tandem , Treonina , Tirosina , Valina
8.
Biomed Pharmacother ; 150: 113026, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35658250

RESUMO

Non-steroidal anti-inflammatory drugs (NSAIDs)-induced gastric ulcers represent a significant clinical concern and adversely affect the quality of life. Inducible nitric oxide synthase/endothelial nitric oxide synthase (iNOS/eNOS) and asymmetric dimethylarginine/ dimethylarginine dimethylaminohydrolase-1 (ADMA/DDAH-1) signaling are key players in gastric ulcer pathogenesis. This work was planned to explore the role of iNOS/eNOS and ADMA/DDAH-1 signaling in rats with indomethacin-induced gastric ulcer, as potential pathways for the gastro-protective effect of tadalafil. Split into 5 separate groups, rats were assigned to control, tadalafil (10 mg/kg, p.o), indomethacin (single oral dose of 60 mg/kg), indomethacin + pantoprazole (40 mg/kg, p.o), and indomethacin + tadalafil (10 mg/kg, p.o). The results indicated that pretreatment with tadalafil significantly reduced ulcer index (UI), increased preventive index (PI), and counteracted indomethacin-induced histopathological aberrations. Tadalafil significantly reduced the gastric content of NO while it significantly elevated that of GSH and enhanced SOD activity. It significantly reduced the gastric expression of TNF-α and ADMA while it significantly elevated that of COX-2, PGE-2, and DDAH-1. Western blot analysis revealed that pretreatment with tadalafil significantly reduced iNOS protein expression while it significantly elevated that of eNOS. Collectively, these data suggest that tadalafil exerts potential protective effect against indomethacin-induced ulcer through suppression of inflammation, attenuation of oxidative stress, and boosting of antioxidants. Moreover, tadalafil protective effects are mediated via upregulation of PGE-2 with modulating the signaling pathways of ADMA/DDAH-1, and iNOS/eNOS. As a result, the current evidence corroborates the use of tadalafil in controlling gastric ulcers and preventing NSAID gastric side effects.


Assuntos
Indometacina , Úlcera Gástrica , Amidoidrolases/metabolismo , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Arginina/farmacologia , Indometacina/uso terapêutico , Indometacina/toxicidade , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Prostaglandinas E/uso terapêutico , Qualidade de Vida , Ratos , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/tratamento farmacológico , Úlcera Gástrica/prevenção & controle , Tadalafila/farmacologia , Tadalafila/uso terapêutico , Úlcera/tratamento farmacológico
9.
Anal Chem ; 94(24): 8774-8782, 2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35666169

RESUMO

Real-time and easy-to-use detection of nucleic acids is crucial for many applications, including medical diagnostics, genetic screening, forensic science, or monitoring the onset and progression of various diseases. Herein, an exploratory single-molecule approach for multiplexed discrimination among similar-sized single-stranded DNAs (ssDNA) is presented. The underlying strategy combined (i) a method based on length-variable, short arginine (poly-Arg) tags appended to peptide nucleic acid (PNA) probes, designed to hybridize with selected regions from complementary ssDNA targets (cDNA) in solution and (ii) formation and subsequent detection with the α-hemolysin nanopore of (poly-Arg)-PNA-cDNA duplexes containing two overhangs associated with the poly-Arg tail and the non-hybridized segment from ssDNA. We discovered that the length-variable poly-Arg tail marked distinctly the molecular processes associated with the nanopore-mediated duplexes capture, trapping and unzipping. This enabled the detection of ssDNA targets via the signatures of (poly-Arg)-PNA-cDNA blockade events, rendered most efficient from the ß-barrel entrance of the nanopore, and scaled proportional in efficacy with a larger poly-Arg moiety. We illustrate the approach by sensing synthetic ssDNAs designed to emulate fragments from two regions of SARS-CoV-2 nucleocapsid phosphoprotein N-gene.


Assuntos
COVID-19 , Nanoporos , Ácidos Nucleicos Peptídicos , Arginina , DNA Complementar , DNA de Cadeia Simples , Humanos , Ácidos Nucleicos Peptídicos/química , Peptídeos , Poli A , Polinucleotídeos , SARS-CoV-2
10.
Biomed Pharmacother ; 152: 113215, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35667234

RESUMO

Oligo-basic amino acids have been extensively studied in molecular biology and pharmacology, but the inhibitory activity on nicotinic acetylcholine receptors (nAChRs) was unknown. In this study, the inhibitory activity of 8 oligopeptides, including both basic and acidic amino acids, was evaluated on 9 nAChR subtypes by a two-electrode voltage clamp (TEVC). Among them, the oligo-lysine K9, K12, d-K9, d-K9F, and oligo-arginine R9 showed nanomolar inhibitory activity on various nAChRs, especially for α7 and α9α10 nAChRs. d-K9 containing N-Fmoc protecting group (d-K9F) has an enhanced inhibitory activity on most of the nAChRs, including 47-fold promotion on α1ß1δε nAChR. However, H9 and H12 only showed weak inhibitory activity on α9α10 and α1ß1δε nAChRs, and the acidic oligopeptide D9 has no inhibitory activity on nAChRs. Flexible docking of K9 in α10(+) α9(-) and α7(+) α7(-) binding pockets showed particularly strong dipole-dipole interactions, which may be responsible for the inhibition of nAChRs. These results demonstrated that oligo-basic amino acids have the potential to be the lead compounds as selective nAChR subtype inhibitors, and oligo-lysines deserved to be modified for further exploitation and utilization. On the other hand, the toxicity and side effects of these nAChR inhibitory peptides should be contemplated in the application.


Assuntos
Receptores Nicotínicos , Aminoácidos Básicos , Arginina , Antagonistas Nicotínicos/farmacologia , Peptídeos/química , Receptores Nicotínicos/metabolismo , Transmissão Sináptica
11.
Carbohydr Polym ; 292: 119648, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-35725158

RESUMO

To better mimic the structure of skin tissue, the use of a multi-layered wound dressing has been proposed. In the present study, a sponge-nanofibrous bi-layer dressing is designed. For this purpose, a chitosan/polyethylene glycol (CsPEG) sponge with advanced platelet-rich fibrin (A-PRF) was prepared as the upper layer of wound dressing, and a Cs/L-arginine electrospun nanofiber layer as the bottom layer. After physical, chemical and mechanical evaluations, the release of platelet-derived growth factor-AB (PDGF-AB), vascular endothelial growth factor (VEGF) and L-arginine were investigated. The antibacterial activity, cell viability and attachment of Bi-layer1.5 dressing (CsPEG/1.5A-PRF sponge coated with Cs/0.5 L-arginine nanofibers) were significantly higher than other dressings. Also, Bi-layer1.5 dressing increased the angiogenic potential and accelerated the wound healing, compared to other samples. Given the promising obtained results, the use of Bi-layer1.5 wound dressing with the ability to release growth factors and L-arginine is highly recommended to treat full-thickness wounds.


Assuntos
Quitosana , Nanofibras , Fibrina Rica em Plaquetas , Antibacterianos/farmacologia , Arginina , Bandagens , Biomimética , Quitosana/química , Nanofibras/química , Fator A de Crescimento do Endotélio Vascular
12.
Biochem Biophys Res Commun ; 617(Pt 2): 55-61, 2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-35696777

RESUMO

The molecular mechanisms of uric acid (UA)-induced liver injury has not been clearly elucidated. In this study, we aimed to investigate the effect and action mechanisms of UA in liver injury. We analyzed the damaging effect of UA on mouse liver and L02 cells and subsequently performed metabolomics studies on L02 cells to identify abnormal metabolic pathways. Finally, we verified transcription factors that regulate related metabolic enzymes. UA directly activated the hepatic NLRP3 inflammasome and Bax apoptosis pathway invivo and invitro. Related metabolites in the arginine biosynthesis pathway (or urea cycle), l-arginine and l-argininosuccinate were decreased, and ammonia was increased in UA-stimulated L02 cells, which was mediated by carbamoyl phosphate synthase 1 (CPS1), argininosuccinate synthase (ASS) and argininosuccinate lyase (ASL) downregulation. UA upregulated hypoxia inducible factor-1alpha (HIF-1α) invivo and invitro, and HIF-1α inhibition alleviated the UA-induced ASS downregulation and hepatocyte injury. In conclusion, UA upregulates HIF-1α and inhibits urea cycle enzymes (UCEs). This leads to liver injury, with evidence of hepatocyte inflammation, apoptosis and oxidative stress.


Assuntos
Hiperuricemia , Animais , Arginina/metabolismo , Argininossuccinato Sintase , Hepatócitos/metabolismo , Humanos , Hiperuricemia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Fígado/metabolismo , Camundongos , Ureia/metabolismo
13.
Pestic Biochem Physiol ; 184: 105107, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35715046

RESUMO

The design and production of molecules capable of mimicking the binding or/and functional sites of proteins inhibitors represent a promising strategy for the exploration and modulation of gut trypsin function in insect pests, specifically Lepidoptera. Here, for the first time, we characterized the trypsin activity present in the gut, performance and development of Anticarsia gemmatalis (Lepidoptera: Noctuidae) larvae when exposed to arginine-containing dipeptides. In silico assessment showed that arginine-containing dipeptides have a greater affinity for the active site of A. gemmatalis trypsins than lysine-containing peptides due to the presence of the double-charged guanidinium group that enhances the interaction at the S1 subsite of trypsins. Furthermore, the inhibitory and anti-insect potential of the peptides was demonstrated through kinetic and larval life cycle parameters, respectively. These dipeptides showed structural stability, binding to the active site, corroborated in vitro (competitive inhibition), and significant reduction of trypsin enzyme activity in the gut, survival, and weight of the A. gemmatalis larvae. Our findings reinforce the idea that small peptides are promising candidates for lepidopteran pest management. The optimization of DI2 and DI1 peptides, enhancing uptake and affinity to trypsins, may turn the use of these molecules feasible in agriculture.


Assuntos
Fabaceae , Mariposas , Animais , Arginina/farmacologia , Dipeptídeos/farmacologia , Insetos , Larva/metabolismo , Mariposas/metabolismo , Soja/metabolismo , Tripsina
14.
Cell Death Dis ; 13(6): 555, 2022 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-35717443

RESUMO

Constitutive activation of cyclin-dependent kinases (CDKs) or arginine auxotrophy are hallmarks of Glioblastoma multiforme (GBM). The latter metabolic defect renders tumor cells vulnerable to arginine-depleting substances, such as arginine deiminase from Streptococcus pyogenes (SpyADI). Previously, we confirmed the susceptibility of patient-derived GBM cells towards SpyADI as well as CDK inhibitors (CDKis). To improve therapeutic effects, we here applied a combined approach based on SpyADI and CDKis (dinaciclib, abemaciclib). Three arginine-auxotrophic patient-derived GBM lines with different molecular characteristics were cultured in 2D and 3D and effects of this combined SpyADI/CDKi approach were analyzed in-depth. All CDKi/SpyADI combinations yielded synergistic antitumoral effects, especially when given sequentially (SEQ), i.e., CDKi in first-line and most pronounced in the 3D models. SEQ application demonstrated impaired cell proliferation, invasiveness, and viability. Mitochondrial impairment was demonstrated by increasing mitochondrial membrane potential and decreasing oxygen consumption rate and extracellular acidification rate after SpyADI/abemaciclib monotherapy or its combination regimens. The combined treatment even induced autophagy in target cells (abemaciclib/SpyADI > dinaciclib/SpyADI). By contrast, the unfolded protein response and p53/p21 induced senescence played a minor role. Transmission electron microscopy confirmed damaged mitochondria and endoplasmic reticulum together with increased vacuolization under CDKi mono- and combination therapy. SEQ-abemaciclib/SpyADI treatment suppressed the DSB repair system via NHEJ and HR, whereas SEQ-dinaciclib/SpyADI treatment increased γ-H2AX accumulation and induced Rad51/Ku80. The latter combination also activated the stress sensor GADD45 and ß-catenin antagonist AXIN2 and induced expression changes of genes involved in cellular/cytoskeletal integrity. This study highlights the strong antitumoral potential of a combined arginine deprivation and CDK inhibition approach via complex effects on mitochondrial dysfunction, invasiveness as well as DNA-damage response. This provides a good starting point for further in vitro and in vivo proof-of-concept studies to move forward with this strategy.


Assuntos
Glioblastoma , Arginina/metabolismo , Autofagia , Linhagem Celular Tumoral , Quinases Ciclina-Dependentes , Glioblastoma/genética , Humanos
15.
Biomed Res ; 43(3): 73-80, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35718447

RESUMO

Arginine methylation is a common post-translational modification which functions as an epigenetic regulator of transcription and plays a key role in various cell signaling pathways. The methylation of arginine residues is catalyzed by protein arginine methyltransferase (PRMT). However, the expression pattern and underlying mechanism of PRMTs and protein methylation profile in lipopolysaccharide (LPS)-induced innate immune responses are poorly understood. Using a shotgun proteomic approach, we found that LPS stimulation increased arginine and proline metabolism and responses to inflammation and bacterial infections. In comparison, cysteine and methionine metabolism, the pentose phosphate pathway, purine metabolism, and protein methylation factors were also decreased in LPS stimulated murine macrophage cell lines. We revealed that LPS stimulation downregulated PRMT1, PRMT5, and protein arginine methylation profiles in RAW264.7 cells using western blot analysis. Additionally, this phenomenon occurred in parallel with nitric oxide accumulation in LPS-induced macrophages. Using inflammation models, we demonstrate for the first time that LPS stimulation decreases PRMTs, leading to the decreasing of arginine methylation in macrophages.


Assuntos
Lipopolissacarídeos , Proteômica , Animais , Arginina , Inflamação/induzido quimicamente , Inflamação/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos/metabolismo , Metilação , Camundongos , Processamento de Proteína Pós-Traducional , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo
16.
Proc Natl Acad Sci U S A ; 119(25): e2204620119, 2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35704760

RESUMO

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 , Mutação
17.
Molecules ; 27(11)2022 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-35684580

RESUMO

The authors of this paper conducted a comparative metabolomic analysis of Ophiocordyceps sinensis (OS), providing the metabolic profiles of the stroma (OSBSz) and sclerotia (OSBSh) of OS by widely targeted metabolomics and untargeted metabolomics. The results showed that 778 and 1449 metabolites were identified by the widely targeted metabolomics and untargeted metabolomics approaches, respectively. The metabolites in OSBSz and OSBSh are significantly differentiated; 71 and 96 differentially expressed metabolites were identified by the widely targeted metabolomics and untargeted metabolomics approaches, respectively. This suggests that these 71 metabolites (riboflavine, tripdiolide, bromocriptine, lumichrome, tetrahymanol, citrostadienol, etc.) and 96 metabolites (sancycline, vignatic acid B, pirbuterol, rubrophen, epalrestat, etc.) are potential biomarkers. 4-Hydroxybenzaldehyde, arginine, and lumichrome were common differentially expressed metabolites. Using the widely targeted metabolomics approach, the key pathways identified that are involved in creating the differentiation between OSBSz and OSBSh may be nicotinate and nicotinamide metabolism, thiamine metabolism, riboflavin metabolism, glycine, serine, and threonine metabolism, and arginine biosynthesis. The differentially expressed metabolites identified using the untargeted metabolomics approach were mainly involved in arginine biosynthesis, terpenoid backbone biosynthesis, porphyrin and chlorophyll metabolism, and cysteine and methionine metabolism. The purpose of this research was to provide support for the assessment of the differences between the stroma and sclerotia, to furnish a material basis for the evaluation of the physical effects of OS, and to provide a reference for the selection of detection methods for the metabolomics of OS.


Assuntos
Arginina/metabolismo , Cordyceps , Arginina/química , Biomarcadores , Metaboloma , Metabolômica/métodos
18.
Cell Rep ; 39(11): 110940, 2022 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-35705029

RESUMO

Tyrosyl-DNA phosphodiesterase (TDP1) hydrolyzes the phosphodiester bond between a DNA 3' end and a tyrosyl moiety and is implicated in the repair of trapped topoisomerase I (Top1)-DNA covalent complexes (Top1cc). Protein arginine methyltransferase 5 (PRMT5) catalyzes arginine methylation of TDP1 at the residues R361 and R586. Here, we establish mechanistic crosstalk between TDP1 arginine methylation and ubiquitylation, which is critical for TDP1 homeostasis and cellular responses to Top1 poisons. We show that R586 methylation promotes TDP1 ubiquitylation, which facilitates ubiquitin/proteasome-dependent TDP1 turnover by impeding the binding of UCHL3 (deubiquitylase enzyme) with TDP1. TDP1-R586 also promotes TDP1-XRCC1 binding and XRCC1 foci formation at Top1cc-damage sites. Intriguingly, R361 methylation enhances the 3'-phosphodiesterase activity of TDP1 in real-time fluorescence-based cleavage assays, and this was rationalized using structural modeling. Together, our findings establish arginine methylation as a co-regulator of TDP1 proteostasis and activity, which modulates the repair of trapped Top1cc.


Assuntos
Adutos de DNA , DNA Topoisomerases Tipo I , Arginina/metabolismo , Reparo do DNA , DNA Topoisomerases Tipo I/metabolismo , Diester Fosfórico Hidrolases/metabolismo , Proteostase , Ubiquitinação
19.
Sci Rep ; 12(1): 9381, 2022 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-35672381

RESUMO

Elevated plasma concentrations of asymmetric dimethylarginine (ADMA) are associated with an increased risk of mortality and adverse cardiovascular outcomes. ADMA can be metabolized by dimethylarginine dimethylaminohydrolases (DDAHs) and by alanine-glyoxylate aminotransferase 2 (AGXT2). Deletion of DDAH1 in mice leads to elevation of ADMA in plasma and increase in blood pressure, while overexpression of human DDAH1 is associated with a lower plasma ADMA concentration and protective cardiovascular effects. The possible role of alternative metabolism of ADMA by AGXT2 remains to be elucidated. The goal of the current study was to test the hypothesis that transgenic overexpression of AGXT2 leads to lowering of plasma levels of ADMA and protection from vascular damage in the setting of DDAH1 deficiency. We generated transgenic mice (TG) with ubiquitous overexpression of AGXT2. qPCR and Western Blot confirmed the expression of the transgene. Systemic ADMA levels were decreased by 15% in TG mice. In comparison with wild type animals plasma levels of asymmetric dimethylguanidino valeric acid (ADGV), the AGXT2 associated metabolite of ADMA, were six times higher. We crossed AGXT2 TG mice with DDAH1 knockout mice and observed that upregulation of AGXT2 lowers plasma ADMA and pulse pressure and protects the mice from endothelial dysfunction and adverse aortic remodeling. Upregulation of AGXT2 led to lowering of ADMA levels and protection from ADMA-induced vascular damage in the setting of DDAH1 deficiency. This is especially important, because all the efforts to develop pharmacological ADMA-lowering interventions by means of upregulation of DDAHs have been unsuccessful.


Assuntos
Arginina , Doenças Vasculares , Amidoidrolases/genética , Amidoidrolases/metabolismo , Animais , Aorta/metabolismo , Arginina/análogos & derivados , Arginina/metabolismo , Pressão Sanguínea , Camundongos , Transaminases/genética , Transaminases/metabolismo
20.
J Vector Borne Dis ; 59(1): 45-51, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35708403

RESUMO

BACKGROUND & OBJECTIVES: Malaria affects around 228 million people all over the globe. Malaria causing parasite Plasmodium infection leads to activation of immune responses. The growth of parasite and immune activation requires semi essential amino acids like L-arginine. Malaria infection leads to condition of hyperargininemia and low availability of nitric oxide. However, the effect of L-arginine supplementation in malaria infected mice has not been explored in in-vivo studies. In this study we have compared the effect of oral supplementation of nitric oxide donor, L-arginine and L-citrulline, in malaria infected mice Methods: To examine the effect of oral supplementation of L-arginine and L-citrulline, Plasmodium berghei infected mice were divided in different groups and respective groups were fed with L- arginine and L-citrulline, parasitemia was measured on different days. Mice was sacrificed and immunophenotyping was done on 10 days post infection. RESULTS: our results show that supplementation of L-arginine induces conducive environment for Plasmodium growth due to which the infected mice dies earlier than control wild type infected mice whereas L-citrulline supplementation inhibits parasite growth and mice survives for longer period of time. Flow cytometric analysis shows that supplementation of L-arginine increases cTLA-4 on T cell population, increases Treg cells leading to immunosuppression while supplementation of L-citrulline does not have effect on T cells population and number of Treg cell decrease compared to P. berghei infected mice. INTERPRETATION & CONCLUSION: our results show that L-citrulline can be a better alternative than L-arginine because of lower expression of inhibitory molecules and lower parasitemia as well as increased survival of infected mice.


Assuntos
Citrulina , Malária , Animais , Arginina/metabolismo , Arginina/farmacologia , Citrulina/metabolismo , Citrulina/farmacologia , Humanos , Malária/prevenção & controle , Camundongos , Parasitemia/prevenção & controle , Plasmodium berghei , Linfócitos T Reguladores/metabolismo , Linfócitos T Reguladores/patologia
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