Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 13.008
Filtrar
1.
Pestic Biochem Physiol ; 200: 105806, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38582572

RESUMO

Boscalid, a widely used SDHI fungicide, has been employed in plant disease control for over two decades. However, there is currently no available information regarding its antifungal activity against Sclerotium rolfsii and the potential risk of resistance development in this pathogen. In this study, we evaluated the sensitivity of 100 S. rolfsii strains collected from five different regions in China during 2018-2019 to boscalid using mycelial growth inhibition method and assessed the risk of resistance development. The EC50 values for boscalid ranged from 0.2994 µg/mL to 1.0766 µg/mL against the tested strains, with an average EC50 value of 0.7052 ± 0.1473 µg/mL. Notably, a single peak sensitivity baseline was curved, indicating the absence of any detected resistant strains. Furtherly, 10 randomly selected strains of S. rolfsii were subjected to chemical taming to evaluate its resistance risk to boscalid, resulting in the successful generation of six stable and inheritable resistant mutants. These mutants exhibited significantly reduced mycelial growth, sclerotia production, and virulence compared to their respective parental strains. Cross-resistance tests revealed a correlation between boscalid and flutolanil, benzovindiflupyr, pydiflumetofen, fluindapyr, and thifluzamide; however, no cross-resistance was observed between boscalid and azoxystrobin. Thus, we conclude that the development risk of resistance in S. rolfsii to boscalid is low. Boscalid can be used as an alternative fungicide for controlling peanut sclerotium blight when combined with other fungicides that have different mechanisms of action. Finally, the target genes SDHB, SDHC, and SDHD in S. rolfsii were initially identified, cloned and sequenced to elucidate the mechanism of S. rolfsii resistance to boscalid. Two mutation genotypes were found in the mutants: SDHD-D111H and SDHD-H121Y. The mutants carrying SDHD-H121Y exhibited moderate resistance, while the mutants with SDHD-D111H showed low resistance. These findings contribute to our comprehensive understanding of molecular mechanisms underlying plant pathogens resistance to SDHI fungicides.


Assuntos
Basidiomycota , Compostos de Bifenilo , Fungicidas Industriais , Niacinamida/análogos & derivados , Fungicidas Industriais/farmacologia , Succinato Desidrogenase , Medição de Risco , Doenças das Plantas/microbiologia
2.
Alzheimers Res Ther ; 16(1): 71, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38576025

RESUMO

BACKGROUND: The aggregation and spread of misfolded amyloid structured proteins, such as tau and α-synuclein, are key pathological features associated with neurodegenerative disorders, including Alzheimer's and Parkinson's disease. These proteins possess a prion-like property, enabling their transmission from cell to cell leading to propagation throughout the central and peripheral nervous systems. While the mechanisms underlying their intracellular spread are still being elucidated, targeting the extracellular space has emerged as a potential therapeutic approach. The glymphatic system, a brain-wide pathway responsible for clearing extracellular metabolic waste from the central nervous system, has gained attention as a promising target for removing these toxic proteins. METHODS: In this study, we investigated the impact of long-term modulation of glymphatic function on tau aggregation and spread by chronically treating a mouse model of tau propagation with a pharmacological inhibitor of AQP4, TGN-020. Thy1-hTau.P301S mice were intracerebrally inoculated with tau into the hippocampus and overlying cortex, and subsequently treated with TGN-020 (3 doses/week, 50 mg/kg TGN-020, i.p.) for 10-weeks. During this time, animal memory was studied using cognitive behavioural tasks, and structural MR images were acquired of the brain in vivo prior to brain extraction for immunohistochemical characterisation. RESULTS: Our findings demonstrate increased tau aggregation in the brain and transhemispheric propagation in the hippocampus following the inhibition of glymphatic clearance. Moreover, disruption of the glymphatic system aggravated recognition memory in tau inoculated mice and exacerbated regional changes in brain volume detected in the model. When initiation of drug treatment was delayed for several weeks post-inoculation, the alterations were attenuated. CONCLUSIONS: These results indicate that by modulating AQP4 function and, consequently, glymphatic clearance, it is possible to modify the propagation and pathological impact of tau in the brain, particularly during the initial stages of the disease. These findings highlight the critical role of the glymphatic system in preserving healthy brain homeostasis and offer valuable insights into the therapeutic implications of targeting this system for managing neurodegenerative diseases characterized by protein aggregation and spread.


Assuntos
Doença de Alzheimer , Sistema Glinfático , Niacinamida/análogos & derivados , Tiadiazóis , Camundongos , Animais , Doença de Alzheimer/patologia , Encéfalo/metabolismo , Sistema Glinfático/metabolismo , Proteínas tau/metabolismo
3.
World J Surg Oncol ; 22(1): 93, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38605359

RESUMO

OBJECTIVE: The clinical efficacy and safety of sorafenib in patients with advanced liver cancer (ALC) were evaluated based on transarterial chemoembolization (TACE). METHODS: 92 patients with ALC admitted to our hospital from May 2020 to August 2022 were randomly rolled into a control (Ctrl) group and an observation (Obs) group, with 46 patients in each. Patients in the Ctrl group received TACE treatment, while those in the Obs group received sorafenib molecular targeted therapy (SMTT) on the basis of the treatment strategy in the Ctrl group (400 mg/dose, twice daily, followed by a 4-week follow-up observation). Clinical efficacy, disease control rate (DCR), survival time (ST), immune indicators (CD3+, CD4+, CD4+/CD8+), and adverse reactions (ARs) (including mild fatigue, liver pain, hand-foot syndrome (HFS), diarrhea, and fever) were compared for patients in different groups after different treatments. RESULTS: the DCR in the Obs group (90%) was greatly higher to that in the Ctrl group (78%), showing an obvious difference (P < 0.05). The median ST in the Obs group was obviously longer and the median disease progression time (DPT) was shorter, exhibiting great differences with those in the Ctrl group (P < 0.05). Moreover, no great difference was observed in laboratory indicators between patients in various groups (P > 0.05). After treatment, the Obs group exhibited better levels in all indicators. Furthermore, the incidence of ARs in the Obs group was lower and exhibited a sharp difference with that in the Ctrl group (P < 0.05). CONCLUSION: SMTT had demonstrated good efficacy in patients with ALC, improving the DCR, enhancing the immune response of the body, and reducing the incidence of ARs, thereby promoting the disease outcome. Therefore, it was a treatment method worthy of promotion and application.


Assuntos
Antineoplásicos , Carcinoma Hepatocelular , Quimioembolização Terapêutica , Neoplasias Hepáticas , Humanos , Sorafenibe/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Antineoplásicos/efeitos adversos , Quimioembolização Terapêutica/métodos , Niacinamida/efeitos adversos , Compostos de Fenilureia/efeitos adversos , Resultado do Tratamento , Terapia Combinada
4.
Clin Cancer Res ; 30(8): 1478-1487, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38593249

RESUMO

PURPOSE: RUNX3 is a tumor suppressor gene, which is inactivated in approximately 70% of lung adenocarcinomas. Nicotinamide, a sirtuin inhibitor, has demonstrated potential in re-activating epigenetically silenced RUNX3 in cancer cells. This study assessed the therapeutic benefits of combining nicotinamide with first-generation EGFR-tyrosine kinase inhibitors (TKI) for patients with stage IV lung cancer carrying EGFR mutations. PATIENTS AND METHODS: We assessed the impact of nicotinamide on carcinogen-induced lung adenocarcinomas in mice and observed that nicotinamide increased RUNX3 levels and inhibited lung cancer growth. Subsequently, 110 consecutive patients with stage IV lung cancer who had EGFR mutations were recruited: 70 females (63.6%) and 84 never-smokers (76.4%). The patients were randomly assigned to receive either nicotinamide (1 g/day, n = 55) or placebo (n = 55). The primary and secondary endpoints were progression-free survival (PFS) and overall survival (OS), respectively. RESULTS: After a median follow-up of 54.3 months, the nicotinamide group exhibited a median PFS of 12.7 months [95% confidence interval (CI), 10.4-18.3], while the placebo group had a PFS of 10.9 months (9.0-13.2; P = 0.2). The median OS was similar in the two groups (31.0 months with nicotinamide vs. 29.4 months with placebo; P = 0.2). Notably, subgroup analyses revealed a significant reduction in mortality risk for females (P = 0.01) and never-smokers (P = 0.03) treated with nicotinamide. CONCLUSIONS: The addition of nicotinamide with EGFR-TKIs demonstrated potential improvements in PFS and OS, with notable survival benefits for female patients and those who had never smoked (ClinicalTrials.gov Identifier: NCT02416739).


Assuntos
Adenocarcinoma de Pulmão , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Feminino , Animais , Camundongos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Niacinamida/uso terapêutico , Prognóstico , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Adenocarcinoma de Pulmão/tratamento farmacológico , Adenocarcinoma de Pulmão/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Mutação , Receptores ErbB/genética
6.
Georgian Med News ; (347): 156-159, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38609134

RESUMO

Objective - to study the Cardioprotective effect of Glycyrriza glabra ethanolic extract and Glycyrrhiza glabra Silver nanoparticle against alloxan and nicotinamide-induced diabetic cardiac injury in adult female Rats. The current study was performed on 36 days in which the G. glabra extract and G. glabra extract loaded on Silver nanoparticles were given to alloxan and nicotinamide-induced diabetic cardiac injured rats. The Cardioprotective effect has been evaluated biochemically. The results of induction of diabetic cardiac injury for 36 days showed a significantly increased (P˂0.05) serum Cardiac Troponin I (cTn-I) and Creatine Kinase (CK-MB) concentration in the diabetic cardiac injury induced (G2) group when compared with the control group (G1), and showed a significant decrease (P˂0.05) in the serum cTn-I and CK-MB concentration in (G3) group (received G. glabra extract) and (G4) group (G.glabra loaded on silver nanoparticle) in comparison with G2. This study concluded that Glycyrriza glabra extract and Glycyrrhiza glabra Silver nanoparticle have a significant Cardioprotective effect induced by alloxan and nicotinamide.


Assuntos
Diabetes Mellitus , Glycyrrhiza , Nanopartículas Metálicas , Extratos Vegetais , Animais , Aloxano , Prata , Niacinamida
7.
Sci Total Environ ; 926: 172035, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38565349

RESUMO

Metabolic alternation is a typical characteristic of insecticide resistance in insects. However, mechanisms underlying metabolic alternation and how altered metabolism in turn affects insecticide resistance are largely unknown. Here, we report that nicotinamide levels are decreased in the imidacloprid-resistant strain of Nilaparvata lugens, may due to reduced abundance of the symbiotic bacteria Arsenophonus. Importantly, the low levels of nicotinamide promote imidacloprid resistance via metabolic detoxification alternation, including elevations in UDP-glycosyltransferase enzymatic activity and enhancements in UGT386B2-mediated metabolism capability. Mechanistically, nicotinamide suppresses transcriptional regulatory activities of cap 'n' collar isoform C (CncC) and its partner small muscle aponeurosis fibromatosis isoform K (MafK) by scavenging the reactive oxygen species (ROS) and blocking the DNA binding domain of MafK. In imidacloprid-resistant N. lugens, nicotinamide deficiency re-activates the ROS/CncC signaling pathway to provoke UGT386B2 overexpression, thereby promoting imidacloprid detoxification. Thus, nicotinamide metabolism represents a promising target to counteract imidacloprid resistance in N. lugens.


Assuntos
Hemípteros , Inseticidas , Animais , Inseticidas/toxicidade , Espécies Reativas de Oxigênio , Neonicotinoides , Nitrocompostos/toxicidade , Transdução de Sinais , Isoformas de Proteínas , Niacinamida
8.
PeerJ ; 12: e17056, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38436036

RESUMO

Balance involves several sensory modalities including vision, proprioception and the vestibular system. This study aims to investigate vestibulospinal activation elicited by tone burst stimulation in various muscles and how head position influences these responses. We recorded electromyogram (EMG) responses in different muscles (sternocleidomastoid-SCM, cervical erector spinae-ES-C, lumbar erector spinae-ES-L, gastrocnemius-G, and tibialis anterior-TA) of healthy participants using tone burst stimulation applied to the vestibular system. We also evaluated how head position affected the responses. Tone burst stimulation elicited reproducible vestibulospinal reflexes in the SCM and ES-C muscles, while responses in the distal muscles (ES-L, G, and TA) were less consistent among participants. The magnitude and polarity of the responses were influenced by the head position relative to the cervical spine. When the head was rotated or tilted, the polarity of the vestibulospinal responses changed, indicating the integration of vestibular and proprioceptive inputs in generating these reflexes. Overall, our study provides valuable insights into the complexity of vestibulospinal reflexes and their modulation by head position. However, the high variability in responses in some muscles limits their clinical application. These findings may have implications for future research in understanding vestibular function and its role in posture and movement control.


Assuntos
Orientação Espacial , Vestíbulo do Labirinto , Humanos , Percepção Espacial , Vértebras Cervicais , Cafeína , Músculos do Pescoço , Niacinamida
9.
Commun Biol ; 7(1): 255, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38429435

RESUMO

Nicotinamide phosphoribosyltransferase (NAMPT) plays an important role in the biosynthesis of nicotinamide adenine dinucleotide (NAD+) via the nicotinamide (NAM) salvage pathway. While the structural biochemistry of eukaryote NAMPT has been well studied, the catalysis mechanism of prokaryote NAMPT at the molecular level remains largely unclear. Here, we demonstrated the NAMPT-mediated salvage pathway is functional in the Gram-negative phytopathogenic bacterium Xanthomonas campestris pv. campestris (Xcc) for the synthesis of NAD+, and the enzyme activity of NAMPT in this bacterium is significantly higher than that of human NAMPT in vitro. Our structural analyses of Xcc NAMPT, both in isolation and in complex with either the substrate NAM or the product nicotinamide mononucleotide (NMN), uncovered significant details of substrate recognition. Specifically, we revealed the presence of a NAM binding tunnel that connects the active site, and this tunnel is essential for both catalysis and inhibitor binding. We further demonstrated that NAM binding in the tunnel has a positive cooperative effect with NAM binding in the catalytic site. Additionally, we discovered that phosphorylation of the His residue at position 229 enhances the substrate binding affinity of Xcc NAMPT and is important for its catalytic activity. This work reveals the importance of NAMPT in bacterial NAD+ synthesis and provides insights into the substrate recognition and the catalytic mechanism of bacterial type II phosphoribosyltransferases.


Assuntos
Niacinamida , Xanthomonas campestris , Humanos , Niacinamida/metabolismo , NAD/metabolismo , Mononucleotídeo de Nicotinamida/metabolismo , Mononucleotídeo de Nicotinamida/farmacologia , Xanthomonas campestris/metabolismo , Nicotinamida Fosforribosiltransferase/química , Nicotinamida Fosforribosiltransferase/metabolismo , Fosforilação
10.
Acta Neuropathol Commun ; 12(1): 37, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38429841

RESUMO

Leber's hereditary optic neuropathy (LHON) is driven by mtDNA mutations affecting Complex I presenting as progressive retinal ganglion cell dysfunction usually in the absence of extra-ophthalmic symptoms. There are no long-term neuroprotective agents for LHON. Oral nicotinamide provides a robust neuroprotective effect against mitochondrial and metabolic dysfunction in other retinal injuries. We explored the potential for nicotinamide to protect mitochondria in LHON by modelling the disease in mice through intravitreal injection of the Complex I inhibitor rotenone. Using MitoV mice expressing a mitochondrial-tagged YFP in retinal ganglion cells we assessed mitochondrial morphology through super-resolution imaging and digital reconstruction. Rotenone induced Complex I inhibition resulted in retinal ganglion cell wide mitochondrial loss and fragmentation. This was prevented by oral nicotinamide treatment. Mitochondrial ultrastructure was quantified by transition electron microscopy, demonstrating a loss of cristae density following rotenone injection, which was also prevented by nicotinamide treatment. These results demonstrate that nicotinamide protects mitochondria during Complex I dysfunction. Nicotinamide has the potential to be a useful treatment strategy for LHON to limit retinal ganglion cell degeneration.


Assuntos
Atrofia Óptica Hereditária de Leber , Rotenona , Camundongos , Animais , Rotenona/toxicidade , Rotenona/metabolismo , Niacinamida/efeitos adversos , Niacinamida/metabolismo , Mitocôndrias/metabolismo , Células Ganglionares da Retina , Atrofia Óptica Hereditária de Leber/genética , Atrofia Óptica Hereditária de Leber/metabolismo , Atrofia Óptica Hereditária de Leber/terapia , Complexo I de Transporte de Elétrons/metabolismo
11.
Int J Mol Sci ; 25(5)2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38474253

RESUMO

The brain's unique characteristics make it exceptionally susceptible to oxidative stress, which arises from an imbalance between reactive oxygen species (ROS) production, reactive nitrogen species (RNS) production, and antioxidant defense mechanisms. This review explores the factors contributing to the brain's vascular tone's vulnerability in the presence of oxidative damage, which can be of clinical interest in critically ill patients or those presenting acute brain injuries. The brain's high metabolic rate and inefficient electron transport chain in mitochondria lead to significant ROS generation. Moreover, non-replicating neuronal cells and low repair capacity increase susceptibility to oxidative insult. ROS can influence cerebral vascular tone and permeability, potentially impacting cerebral autoregulation. Different ROS species, including superoxide and hydrogen peroxide, exhibit vasodilatory or vasoconstrictive effects on cerebral blood vessels. RNS, particularly NO and peroxynitrite, also exert vasoactive effects. This review further investigates the neuroprotective effects of antioxidants, including superoxide dismutase (SOD), vitamin C, vitamin E, and the glutathione redox system. Various studies suggest that these antioxidants could be used as adjunct therapies to protect the cerebral vascular tone under conditions of high oxidative stress. Nevertheless, more extensive research is required to comprehensively grasp the relationship between oxidative stress and cerebrovascular tone, and explore the potential benefits of antioxidants as adjunctive therapies in critical illnesses and acute brain injuries.


Assuntos
Lesões Encefálicas , Oxigênio , Humanos , Espécies Reativas de Oxigênio/metabolismo , Oxigênio/farmacologia , Nitrogênio/farmacologia , Estresse Oxidativo , Antioxidantes/farmacologia , Espécies Reativas de Nitrogênio/metabolismo , Niacinamida/farmacologia , Lesões Encefálicas/tratamento farmacológico
12.
Environ Toxicol Chem ; 43(5): 976-987, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38488751

RESUMO

There is a growing concern that chronic exposure to fungicides contributes to negative effects on honey bee development, life span, and behavior. Field and caged-bee studies have helped to characterize the adverse outcomes (AOs) of environmentally relevant exposures, but linking AOs to molecular/cellular mechanisms of toxicity would benefit from the use of readily controllable, simplified host platforms like cell lines. Our objective was to develop and optimize an in vitro-based mitochondrial toxicity assay suite using the honey bee as a model pollinator, and the electron transport chain (ETC) modulators boscalid and pyraclostrobin as model fungicides. We measured the effects of short (~30 min) and extended exposures (16-24 h) to boscalid and pyraclostrobin on AmE-711 honey bee cell viability and mitochondrial function. Short exposure to pyraclostrobin did not affect cell viability, but extended exposure reduced viability in a concentration-dependent manner (median lethal concentration = 4175 µg/L; ppb). Mitochondrial membrane potential (MMP) was affected by pyraclostrobin in both short (median effect concentration [EC50] = 515 µg/L) and extended exposure (EC50 = 982 µg/L) scenarios. Short exposure to 10 and 1000 µg/L pyraclostrobin resulted in a rapid decrease in the oxygen consumption rate (OCR), approximately 24% reduction by 10 µg/L relative to the baseline OCR, and 64% by 1000 µg/L. Extended exposure to 1000 µg/L pyraclostrobin reduced all respiratory parameters (e.g., spare capacity, coupling efficiency), whereas 1- and 10-µg/L treatments had no significant effects. The viability of AmE-711 cells, as well as the MMP and cellular respiration were unaffected by short and extended exposures to boscalid. The present study demonstrates that the AmE-711-based assessment of viability, MMP, and ETC functionality can provide a time- and cost-effective platform for mitochondrial toxicity screening relevant to bees. Environ Toxicol Chem 2024;43:976-987. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.


Assuntos
Compostos de Bifenilo , Sobrevivência Celular , Fungicidas Industriais , Mitocôndrias , Niacinamida , Niacinamida/análogos & derivados , Estrobilurinas , Animais , Estrobilurinas/toxicidade , Abelhas/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Fungicidas Industriais/toxicidade , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Niacinamida/farmacologia , Niacinamida/toxicidade , Potencial da Membrana Mitocondrial/efeitos dos fármacos
13.
Environ Pollut ; 347: 123685, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38460591

RESUMO

Boscalid (2-Chloro-N-(4'-chlorobiphenyl-2-yl) nicotinamide), a pyridine carboxamide fungicide, is an inhibitor of the complex II of the respiration chain in fungal mitochondria. As boscalid is only moderately toxic for aquatic organisms (LC50 > 1-10 mg/L), current environmental levels of this compound in aquatic ecosystems, in the range of ng/L-µg/L, are considered safe for aquatic organisms. In this study, we have exposed zebrafish (Danio rerio), Japanese medaka (Oryzias latipes) and Daphnia magna to a range of concentrations of boscalid (1-1000 µg/L) for 24 h, and the effects on heart rate (HR), basal locomotor activity (BLA), visual motor response (VMR), startle response (SR), and habituation (HB) to a series of vibrational or light stimuli have been evaluated. Moreover, changes in the profile of the main neurotransmitters have been determined. Boscalid altered HR in a concentration-dependent manner, leading to a positive or negative chronotropic effect in fish and D. magna, respectively. While boscalid decreased BLA and increased VMR in Daphnia, these behaviors were not altered in fish. For SR and HB, the response was more species- and concentration-specific, with Daphnia exhibiting the highest sensitivity. At the neurotransmission level, boscalid exposure decreased the levels of L-aspartic acid in fish larvae and increased the levels of dopaminergic metabolites in D. magna. Our study demonstrates that exposure to environmental levels of boscalid alters cardiac activity, impairs ecologically relevant behaviors, and leads to changes in different neurotransmitter systems in phylogenetically distinct vertebrate and invertebrate models. Thus, the results presented emphasize the need to review the current regulation of this fungicide.


Assuntos
Compostos de Bifenilo , Fungicidas Industriais , Niacinamida/análogos & derivados , Poluentes Químicos da Água , Animais , Fungicidas Industriais/metabolismo , Ecossistema , Organismos Aquáticos , Peixe-Zebra/metabolismo , Daphnia , Niacinamida/toxicidade , Poluentes Químicos da Água/metabolismo
14.
Biochem Biophys Res Commun ; 708: 149778, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38507867

RESUMO

The increasing prevalence of lean diabetes has prompted the generation of animal models that mimic metabolic disease in humans. This study aimed to determine the optimum streptozotocin-nicotinamide (STZ-NA) dosage ratio to elicit lean diabetic features in a rat model. It also used a proton nuclear magnetic resonance (1H NMR) urinary metabolomics approach to identify the metabolic effect of metformin treatment on this novel rat model. Three different STZ-NA dosage regimens (by body weight: Group A: 110 mg/kg NA and 45 mg/kg STZ; Group B: 180 mg/kg NA and 65 mg/kg STZ and Group C: 120 mg/kg NA and 60 mg/kg STZ) were administered to Sprague-Dawley rats along with oral metformin. Group A diabetic rats (A-DC) showed favorable serum biochemical analyses and a more positive response toward oral metformin administration relative to the other STZ-NA dosage ratio groups. Orthogonal partial least squares-discriminant analysis (OPLS-DA) revealed that glucose, citrate, pyruvate, hippurate, and methylnicotinamide differentiating the OPLS-DA of A-MTF rats (Group A diabetic rats treated with metformin) and A-DC model rats. Subsequent metabolic pathway analyses revealed that metformin treatment was associated with improvement in dysfunctions caused by STZ-NA induction, including carbohydrate metabolism, cofactor metabolism, and vitamin and amino acid metabolism. In conclusion, our results identify the best STZ-NA dosage ratio for a rat model to exhibit lean type 2 diabetic features with optimum sensitivity to metformin treatment. The data presented here could be informative to improve our understanding of non-obese diabetes in humans through the identification of possible activated metabolic pathways in the STZ-NA-induced diabetic rats model.


Assuntos
Diabetes Mellitus Experimental , Metformina , Humanos , Ratos , Animais , Metformina/uso terapêutico , Metformina/farmacologia , Niacinamida/efeitos adversos , Estreptozocina , Diabetes Mellitus Experimental/metabolismo , Ratos Sprague-Dawley , Espectroscopia de Prótons por Ressonância Magnética , Metabolômica/métodos , Espectroscopia de Ressonância Magnética , Hipoglicemiantes/farmacologia , Glicemia/análise
15.
JASA Express Lett ; 4(3)2024 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-38426890

RESUMO

English-speaking bimodal and bilateral cochlear implant (CI) users can segregate competing speech using talker sex cues but not spatial cues. While tonal language experience allows for greater utilization of talker sex cues for listeners with normal hearing, tonal language benefits remain unclear for CI users. The present study assessed the ability of Mandarin-speaking bilateral and bimodal CI users to recognize target sentences amidst speech maskers that varied in terms of spatial cues and/or talker sex cues, relative to the target. Different from English-speaking CI users, Mandarin-speaking CI users exhibited greater utilization of spatial cues, particularly in bimodal listening.


Assuntos
Implantes Cocleares , Percepção da Fala , Humanos , Fala , Sinais (Psicologia) , Idioma , Cafeína , Niacinamida
16.
Methods Cell Biol ; 185: 165-195, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38556447

RESUMO

The mucosal surface of gastrointestinal tract is lined with epithelial cells that establish an effective barrier between the lumen and internal environment through intercellular junctions, preventing the passage of potentially harmful substances. The "intestinal barrier function" consist of a defensive system that prevent the passage of antigens, toxins, and microbial products, while maintains the correct development of the epithelial barrier, the immune system and the acquisition of tolerance toward dietary antigens and intestinal microbiota. Intestinal morphology changes subsequent to nutritional variations, stress, aging or diseases, which can also affect the composition of the microbiota, altering the homeostasis of the intestine. A growing body of evidence suggests that alterations in intestinal barrier function favor the development of exaggerated immune responses, leading to metabolic endotoxemia, which seems to be the origin of many chronic metabolic diseases such as type 2 diabetes mellitus (T2DM). Although the mechanisms are still unknown, the interaction between dietary patterns, gut microbiota, intestinal mucosa, and metabolic inflammation seems to be a key factor for the development of T2DM, among other diseases. This chapter details the different techniques that allow evaluating the morphological and molecular alterations that lead of the intestinal barrier dysfunction in a T2DM experimental model. To induce both diabetic metabolic disturbances and gut barrier disruption, Wistar rats were fed a high-saturated fat and high-cholesterol diet and received a single dose of streptozotocin/nicotinamide. This animal model may contribute to clarify the understanding of the role of intestinal barrier dysfunction on the late-stage T2DM etiology.


Assuntos
Diabetes Mellitus Tipo 2 , Ratos , Animais , Diabetes Mellitus Tipo 2/metabolismo , Estreptozocina/metabolismo , Niacinamida/farmacologia , Niacinamida/metabolismo , Ratos Wistar , Mucosa Intestinal/metabolismo , Colesterol/metabolismo
17.
J Med Chem ; 67(6): 4463-4482, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38471014

RESUMO

Sorafenib, a multiple kinase inhibitor, is widely used as a first-line treatment for hepatocellular carcinoma. However, there is a need for more effective alternatives when sorafenib proves insufficient. In this study, we aimed to design a structure that surpasses sorafenib's efficacy, leading us to synthesize sorafenib-ruthenium complexes for the first time and investigate their properties. Our results indicate that the sorafenib-ruthenium complexes exhibit superior epidermal growth factor receptor (EGFR) inhibition compared to sorafenib alone. Interestingly, among these complexes, Ru3S demonstrated high activity against various cancer cell lines including sorafenib-resistant HepG2 cells while exhibiting significantly lower cytotoxicity than sorafenib in healthy cell lines. Further evaluation of cell cycle, cell apoptosis, and antiangiogenic effects, molecular docking, and molecular dynamics studies revealed that Ru3S holds great potential as a drug candidate. Additionally, when free Ru3S was encapsulated into polymeric micelles M1, enhanced cytotoxicity on HepG2 cells was observed. Collectively, these findings position Ru3S as a promising candidate for EGFR inhibition and warrant further exploration for drug development purposes.


Assuntos
Antineoplásicos , Carcinoma Hepatocelular , Neoplasias Hepáticas , Rutênio , Humanos , Sorafenibe/farmacologia , Rutênio/farmacologia , Simulação de Acoplamento Molecular , Neoplasias Hepáticas/tratamento farmacológico , Compostos de Fenilureia/farmacologia , Niacinamida/farmacologia , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Receptores ErbB/metabolismo , Apoptose , Sistemas de Liberação de Medicamentos , Proliferação de Células
18.
Transl Vis Sci Technol ; 13(3): 24, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38546981

RESUMO

Purpose: To investigate the potential effects and mechanism of nicotinamide riboside (NR) on the oxidative stress and fibrosis model of human trabecular meshwork (HTM) cell line cells. Methods: HTM cells were pretreated with NR, followed by the induction of oxidative injury and fibrosis by hydrogen peroxide (H2O2) and TGF-ß2, respectively. Cell viability was tested using Hoechst staining and MTT assays, cell proliferation was assessed by EdU assay, and cell apoptosis was detected by flow cytometry and western blotting. DCFH-DA and DHE probes were used to measure the level of reactive oxygen species (ROS), and MitoTracker staining was used to measure the mitochondrial membrane potential (MMP). Fibrotic responses, including cell migration and deposition of extracellular matrix (ECM) proteins, were detected via Transwell assays, qRT-PCR, and immunoblotting. Results: NR pretreatment improved the viability, proliferation, and MMP of H2O2-treated HTM cells. Compared to cells treated solely with H2O2, HTM cells treated with both NR and H2O2, exhibited a reduced rate of apoptosis and generation of ROS. Compared with H2O2 pretreatment, NR pretreatment upregulated expression of the JAK2/Stat3 pathway but inhibited mitogen-activated protein kinase (MAPK) pathway expression. Moreover, 10-ng/mL TGF-ß2 promoted cell proliferation and migration, which were inhibited by NR pretreatment. Both qRT-PCR and immunoblotting showed that NR inhibited the expression of fibronectin in a TGF-ß2-induced fibrosis model. Conclusions: NR has a protective effect on oxidative stress and fibrosis in HTM cells, which may be related to the JAK2/Stat3 pathway and MAPK pathway. Translational Relevance: Our research provides the ongoing data for potential therapy of NAD+ precursors in glaucoma.


Assuntos
Niacinamida/análogos & derivados , Compostos de Piridínio , Malha Trabecular , Fator de Crescimento Transformador beta2 , Humanos , Espécies Reativas de Oxigênio/metabolismo , Espécies Reativas de Oxigênio/farmacologia , Fator de Crescimento Transformador beta2/metabolismo , Fator de Crescimento Transformador beta2/farmacologia , Malha Trabecular/metabolismo , Malha Trabecular/patologia , Peróxido de Hidrogênio/farmacologia , Peróxido de Hidrogênio/metabolismo , Estresse Oxidativo/fisiologia , Fibrose
19.
Environ Int ; 186: 108608, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38554503

RESUMO

Bumblebees are among the most important wild bees for pollination of crops and securing wildflower diversity. However, their abundance and diversity have been on a steady decrease in the last decades. One of the most important factors leading to their decline is the frequent use of plant protection products (PPPs) in agriculture, which spread into forests and natural reserves. Mixtures of different PPPs pose a particular threat because of possible synergistic effects. While there is a comparatively large body of studies on the effects of PPPs on honeybees, we still lack data on wild bees. We here investigated the influence of the frequent fungicide Cantus® Gold (boscalid/dimoxystrobin), the neonicotinoid insecticide Mospilan® (acetamiprid) and their combination on bumblebees. Cognitive performance and foraging flights of bumblebees were studied. They are essential for the provisioning and survival of the colony. We introduce a novel method for testing four treatments simultaneously on the same colony, minimizing inter-colony differences. For this, we successfully quartered the colony and moved the queen daily between compartments. Bumblebees appeared astonishingly resilient to the PPPs tested or they have developed mechanisms for detoxification. Neither learning capacity nor flight activity were inhibited by treatment with the single PPPs or their combination.


Assuntos
Compostos de Bifenilo , Fungicidas Industriais , Neonicotinoides , Niacinamida/análogos & derivados , Abelhas/efeitos dos fármacos , Abelhas/fisiologia , Animais , Fungicidas Industriais/toxicidade , Estrobilurinas , Inseticidas/toxicidade , Piridinas/toxicidade
20.
Physiol Behav ; 278: 114521, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38492911

RESUMO

Epilepsy is a neurological condition distinguished by recurrent and unexpected seizures. Astrocytic channels and transporters are essential for maintaining normal neuronal functionality. The astrocytic water channel, aquaporin-4 (AQP4), which plays a pivotal role in regulating water homeostasis, is a potential target for epileptogenesis. In present study, we examined the effect of different doses (10, 50, 100 µM and 5 mM) of AQP4 inhibitor, 2-nicotinamide-1, 3, 4-thiadiazole (TGN-020), during kindling acquisition, on seizure parameters and seizure-induced cognitive impairments. Animals were kindled by injection of pentylenetetrazole (PTZ: 37.5 mg/kg, i.p.). TGN-020 was administered into the right lateral cerebral ventricle 30 min before PTZ every alternate day. Seizure parameters were assessed 20 min after PTZ administration. One day following the last PTZ injection, memory performance was investigated using spontaneous alternation in Y-maze and novel object recognition (NOR) tests. The inhibition of AQP4 during the kindling process significantly decreased the maximal seizure stage and seizure duration (two-way ANOVA, P = 0.0001) and increased the latency of seizure onset and the number of PTZ injections required to induce different seizure stages (one-way ANOVA, P = 0.0001). Compared to kindled rats, the results of the NOR tests showed that AQP4 inhibition during PTZ-kindling prevented recognition memory impairment. Based on these results, AQP4 could be involved in seizure development and seizure-induced cognitive impairment. More investigation is required to fully understand the complex interactions between seizure activity, water homeostasis, and cognitive dysfunction, which may help identify potential therapeutic targets for these conditions.


Assuntos
Aquaporina 4 , Disfunção Cognitiva , Excitação Neurológica , Niacinamida , Tiadiazóis , Animais , Ratos , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/tratamento farmacológico , Niacinamida/administração & dosagem , Niacinamida/análogos & derivados , Pentilenotetrazol , Convulsões/induzido quimicamente , Convulsões/complicações , Convulsões/tratamento farmacológico , Tiadiazóis/administração & dosagem , Água/efeitos adversos , Aquaporina 4/antagonistas & inibidores
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...