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1.
Am J Pathol ; 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38885924

RESUMO

Bifidobacterium bifidum strain BB1 causes a strain-specific enhancement in intestinal epithelial tight junction (TJ) barrier. Tumor necrosis factor (TNF)-α induces an increase in intestinal epithelial TJ permeability and promotes intestinal inflammation. The major purpose of this study was to delineate the protective effect of BB1 against the TNF-α-induced increase in intestinal TJ permeability and to unravel the intracellular mechanisms involved. Previously reported, TNF-α produces an increase in intestinal epithelial TJ permeability in Caco-2 monolayers and in mice. The addition of BB1 inhibited the TNF-α increase in Caco-2 intestinal TJ permeability and mouse intestinal permeability in a strain-specific manner. BB1 inhibited the TNF-α-induced increase in intestinal TJ permeability by interfering the with TNF-α-induced enterocyte NF-κB p50/p65 and myosin light chain kinase (MLCK) gene activation. The BB1 protective effect against the TNF-α-induced increase in intestinal permeability was mediated by toll-like receptor-2/toll-like receptor-6 heterodimer complex activation of peroxisome proliferator-activated receptor γ (PPAR-γ) and PPAR-γ pathway inhibition of TNF-α-induced IKK-α activation, which, in turn, resulted in a step-wise inhibition of NF-κB p50/p65, MLCK gene, MLCK kinase activity, and MLCK-induced opening of the TJ barrier. In conclusion, these studies unravel novel intracellular mechanisms of BB1 protection against the TNF-α-induced increase in intestinal TJ permeability. Our data show that BB1 protects against the TNF-α-induced increase in intestinal epithelial TJ permeability via a PPAR-γ-dependent inhibition of NF-κB p50/p65 and MLCK gene activation.

2.
Haematologica ; 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38450530

RESUMO

Comprehensive genomic sequencing is becoming a critical component in the assessment of hematologic malignancies, with broad implications for patient management. In this context, unequivocally discriminating somatic from germline events is challenging but greatly facilitated by matched analysis of tumor:normal pairs. In contrast to solid tumors, conventional sources of normal control (peripheral blood, buccal swabs, saliva) could be highly involved by the neoplastic process, rendering them unsuitable. In this work we describe our real-world experience using cell free DNA (cfDNA) isolated from nail clippings as an alternate source of normal control, through the dedicated review of 2,610 tumor:nail pairs comprehensively sequenced by MSK-IMPACT-heme. Overall, we find nail cfDNA is a robust source of germline control for paired genomic studies. In a subset of patients, nail DNA may have tumor DNA contamination, reflecting unique attributes of the hematologic disease and transplant history. Contamination is generally low level, but significantly more common among patients with myeloid neoplasms (20.5%; 304/1482) compared to lymphoid diseases (5.4%; 61/1128) and particularly enriched in myeloproliferative neoplasms with marked myelofibrosis. When identified in patients with lymphoid and plasma-cell neoplasms, mutations commonly reflected a myeloid profile and correlated with a concurrent/evolving clonal myeloid neoplasm. For nails collected after allogeneic stem-cell transplantation, donor DNA was identified in 22% (11/50). In this cohort, an association with recent history of graft-vs-host disease was identified. These findings should be considered as a potential limitation for the use of nail as normal control but could also provide important diagnostic information regarding the disease process.

3.
Curr Genomics ; 25(2): 105-119, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38751600

RESUMO

Background: The plasma virome represents the overall composition of viral sequences present in it. Alteration in plasma virome has been reported in treatment naïve and immunocompromised (CD4 count < 200) people with HIV (PWH). However, the effect of ART on virome composition in PWH on ART with preserved CD4 counts is poorly understood. Objectives: We aimed to assess the alterations in plasma virome in PWH on ART in comparison to HIV-negative uninfected controls and to further investigate possible associations of plasma viruses with inflammation and immune dysfunction, namely, immunosenescence and immune exhaustion. Methods: Plasma viral DNA from PWH on ART and controls was used for sequencing on the Illumina Nextseq500 platform, followed by the identification of viral sequences using an automated pipeline, VIROMATCH. Multiplex cytokine assay was performed to measure the concentrations of various cytokines in plasma. Immunophenotyping was performed on PBMCs to identify T cell markers of immunosenescence and immune exhaustion. Results: In our observational, cross-sectional pilot study, chronically infected PWH on ART had significantly different viral species compositions compared to controls. The plasma virome of PWH showed a significantly high relative abundance of species Human gammaherpesvirus 4, also known as Epstein-Barr virus (EBV). Moreover, EBV emerged as a significant viral taxon differentially enriched in PWH on ART, which further correlated positively with the exhaustion phenotype of T cells and significantly increased TNF-α in PWH on ART. Additionally, a significantly increased proportion of senescent T cells and IL-8 cytokine was detected in PWH on ART. Conclusion: Altered plasma virome influenced the inflammatory response and T-cell phenotype in PWH on ART.

4.
Artigo em Inglês | MEDLINE | ID: mdl-38581340

RESUMO

Objectives: Continuous and excessive secretion of pro-inflammatory and anti-inflammatory chemicals and cytokines may further deteriorate inflammation. Anti-inflammatory drugs play an imperative role in inhibiting the evolution of inflammatory diseases. As per the Unani doctrine, a holistic treatment approach is used to treat illnesses. Therefore, drugs having different actions are used to achieve the synergic effect. Three drugs (Cinnamomum zeylanicum, Alpinia galanga, and Withania somnifera), which are frequently used in Unani medicine for joint disorders were selected to evaluate the anti-inflammatory activity of the extract derived from them. Methods: We used RAW 264.7 macrophage cells to see the expression of inflammatory markers IL-1ß, IL-6, and TNF-α. Cytotoxic activity was assessed with MTT assay and Nitric Oxide (NO) was evaluated using Griess reagent. Further, anti-inflammatory activity was evaluated in Wistar Albino rats using carrageenan-induced paw oedema and immunohistochemistry assays for Cyclooxygenase-2 (COX-2). All the data were analyzed using ANOVA and Dunnett t test for multiple comparisons. Results: This extract did not show any cytotoxic effect and the gene expression was significantly reduced for IL-1ß, IL-6, and TNF-α in a dose-dependent manner. Further, NO production was also significantly reduced in the test groups. Immunohistochemistry revealed that the test groups had less inflammation as compared to the control group. Conclusion: It may be inferred that the ethanolic extract of the three herbs has strong anti-inflammatory activity in the tested inflammatory models and the extract is safe as it did not show any cytotoxic effects in both in vitro and in vivo conditions.

5.
Sensors (Basel) ; 24(13)2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-39000972

RESUMO

With the continuous development of new sensor features and tracking algorithms for object tracking, researchers have opportunities to experiment using different combinations. However, there is no standard or agreed method for selecting an appropriate architecture for autonomous vehicle (AV) crash reconstruction using multi-sensor-based sensor fusion. This study proposes a novel simulation method for tracking performance evaluation (SMTPE) to solve this problem. The SMTPE helps select the best tracking architecture for AV crash reconstruction. This study reveals that a radar-camera-based centralized tracking architecture of multi-sensor fusion performed the best among three different architectures tested with varying sensor setups, sampling rates, and vehicle crash scenarios. We provide a brief guideline for the best practices in selecting appropriate sensor fusion and tracking architecture arrangements, which can be helpful for future vehicle crash reconstruction and other AV improvement research.

6.
J Vector Borne Dis ; 61(1): 123-128, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38648414

RESUMO

BACKGROUND OBJECTIVES: Bangladesh is afflicted with periodic dengue outbreak every few years and one of the worst upsurges was recorded in 2019 during which there was an increasing trend of dengue with unusual symptoms which were not so common before. This study aims to describe the experience of three tertiary care centres of Dhaka regarding the clinical and laboratory, hospital outcome and management profile of the Expanded Dengue Syndrome (EDS) cases admitted from the 2019 outbreak. METHODS: The current work was a cross-sectional observational study which took place from August 1 to December 31 2019 at three major tertiary care centres in Dhaka, Bangladesh. Out of total 2017 screened dengue cases, 49 met the inclusion criteria and 39 were enrolled after taking informed written consent. Data was analysed using Microsoft Excel and Graph pad prism 9.3.1. A probability value of p<0.05 was considered statistically significant. RESULTS: Out of the 39 cases, majority were male (79.49%) with median (±IQR) age of 33(±9) years. Hypertension (4; 10.26%) was the most commonly associated co-morbidity. Among the systemic manifestations, most prevalent was hepatitis (38.49%) followed by encephalopathy (12.82%). Majority of the patients were suffering from primary infection (85%). Case fatality rate was 15.38%. Hepatitis and meningoencephalitis were the predominant cause of death. This study records the only known case report of Acute respiratory dress syndrome (ARDS) complicating dengue from Bangladesh. None of the patients from our cohort were managed by steroids. Only two (5.13%) out of 39 cases received antibiotics. INTERPRETATION CONCLUSION: In the year 2019, an unusual rise in EDS cases with about 15.4% fatalities were observed in this study. Hepatitis was the most common presentation and cause of death. Here, we report the first ARDS case encountered in Bangladesh. Despite the multifaceted presentation of EDS, indiscriminate use of antibiotics and steroid was minimal. Early recognition of multifarious features of EDS is important for choosing the targeted treatment option which can avert many deaths. The results of this study underline the necessity for more in-depth research into the risk factors that are contributing to mortality in EDS cases.


Assuntos
Dengue , Surtos de Doenças , Centros de Atenção Terciária , Humanos , Bangladesh/epidemiologia , Masculino , Feminino , Adulto , Estudos Transversais , Dengue/epidemiologia , Dengue/diagnóstico , Adulto Jovem , Centros de Atenção Terciária/estatística & dados numéricos , Pessoa de Meia-Idade
7.
Proc Natl Acad Sci U S A ; 117(17): 9497-9507, 2020 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-32300005

RESUMO

Nitric oxide (NO) produced by endothelial nitric oxide synthase (eNOS) is a critical mediator of vascular function. eNOS is tightly regulated at various levels, including transcription, co- and posttranslational modifications, and by various protein-protein interactions. Using stable isotope labeling with amino acids in cell culture (SILAC) and mass spectrometry (MS), we identified several eNOS interactors, including the protein plasminogen activator inhibitor-1 (PAI-1). In cultured human umbilical vein endothelial cells (HUVECs), PAI-1 and eNOS colocalize and proximity ligation assays demonstrate a protein-protein interaction between PAI-1 and eNOS. Knockdown of PAI-1 or eNOS eliminates the proximity ligation assay (PLA) signal in endothelial cells. Overexpression of eNOS and HA-tagged PAI-1 in COS7 cells confirmed the colocalization observations in HUVECs. Furthermore, the source of intracellular PAI-1 interacting with eNOS was shown to be endocytosis derived. The interaction between PAI-1 and eNOS is a direct interaction as supported in experiments with purified proteins. Moreover, PAI-1 directly inhibits eNOS activity, reducing NO synthesis, and the knockdown or antagonism of PAI-1 increases NO bioavailability. Taken together, these findings place PAI-1 as a negative regulator of eNOS and disruptions in eNOS-PAI-1 binding promote increases in NO production and enhance vasodilation in vivo.


Assuntos
Regulação Enzimológica da Expressão Gênica/fisiologia , Óxido Nítrico Sintase Tipo III/metabolismo , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Disponibilidade Biológica , Linhagem Celular , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana , Humanos , Óxido Nítrico , Óxido Nítrico Sintase Tipo III/genética , Piperazinas/farmacologia , Inibidor 1 de Ativador de Plasminogênio/genética , Ligação Proteica , Vasodilatação/efeitos dos fármacos , Vasodilatação/fisiologia , para-Aminobenzoatos/farmacologia
8.
Am J Pathol ; 191(5): 872-884, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33607043

RESUMO

Defective intestinal tight junction (TJ) barrier is an important pathogenic factor of inflammatory bowel disease. To date, no effective therapies that specifically target the intestinal TJ barrier are available. The purpose of this study was to identify probiotic bacterial species or strains that induce a rapid and sustained enhancement of intestinal TJ barrier and protect against the development of intestinal inflammation by targeting the TJ barrier. After high-throughput screening of >20 Lactobacillus and other probiotic bacterial species or strains, a specific strain of Lactobacillus acidophilus, referred to as LA1, uniquely produced a marked enhancement of the intestinal TJ barrier. LA1 attached to the apical membrane surface of intestinal epithelial cells in a Toll-like receptor (TLR)-2-dependent manner and caused a rapid increase in enterocyte TLR-2 membrane expression and TLR-2/TLR-1 and TLR-2/TLR-6 hetero-complex-dependent enhancement in intestinal TJ barrier function. Oral administration of LA1 caused a rapid enhancement in mouse intestinal TJ barrier, protected against a dextran sodium sulfate (DSS) increase in intestinal permeability, and prevented the DSS-induced colitis in a TLR-2- and intestinal TJ barrier-dependent manner. In conclusion, we report for the first time that a specific strain of LA causes a strain-specific enhancement of intestinal TJ barrier through a novel mechanism that involves the TLR-2 receptor complex and protects against the DSS-induced colitis by targeting the intestinal TJ barrier.


Assuntos
Colite/prevenção & controle , Inflamação/prevenção & controle , Lactobacillus acidophilus/fisiologia , Probióticos , Receptor 2 Toll-Like/metabolismo , Animais , Colite/induzido quimicamente , Colite/microbiologia , Colite/patologia , Sulfato de Dextrana/efeitos adversos , Células Epiteliais/patologia , Intestinos/efeitos dos fármacos , Intestinos/patologia , Camundongos , Camundongos Endogâmicos C57BL , Permeabilidade/efeitos dos fármacos , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/patologia , Receptor 2 Toll-Like/genética
9.
Environ Sci Technol ; 56(21): 14891-14903, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36102785

RESUMO

Food production environments in low- and middle-income countries (LMICs) are recognized as posing significant and increasing risks to antimicrobial resistance (AMR), one of the greatest threats to global public health and food security systems. In order to maximize and expedite action in mitigating AMR, the World Bank and AMR Global Leaders Group have recommended that AMR is integrated into wider sustainable development strategies. Thus, there is an urgent need for tools to support decision makers in unravelling the complex social and environmental factors driving AMR in LMIC food-producing environments and in demonstrating meaningful connectivity with other sustainable development issues. Here, we applied the Driver-Pressure-State-Impact-Response (DPSIR) conceptual framework to an aquaculture case study site in rural Bangladesh, through the analysis of distinct social, microbiological, and metagenomic data sets. We show how the DPSIR framework supports the integration of these diverse data sets, first to systematically characterize the complex network of societal drivers of AMR in these environments and second to delineate the connectivity between AMR and wider sustainable development issues. Our study illustrates the complexity and challenges of addressing AMR in rural aquaculture environments and supports efforts to implement global policy aimed at mitigating AMR in aquaculture and other rural LMIC food-producing environments.


Assuntos
Antibacterianos , Farmacorresistência Bacteriana , Humanos , Antibacterianos/farmacologia , Aquicultura , População Rural , Saúde Global
10.
Mol Biol Rep ; 49(11): 10895-10904, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35941412

RESUMO

Arsenic (As) is a global carcinogenic contaminant, and is one of the significant environmental constraints that limits the development and yield of crop plants. It is always tagged along with rice as rice takes up As and tends to accumulate it in grains. This amassment makes a way for As to get into the food chain that leads to unforeseen human health risks. Being viewed as parallel with toxicity, As in rice is an important global risk that calls for an urgent solution. WRKY Transcription Factors (TFs) seems to be promising in this area. The classical and substantial progress in the molecular mechanism of WRKY TFs, strengthened the understanding of innovative solutions for dealing with As in rice. Here, we review the potential of WRKY TFs under As stressed rice as a genetic solution and also provide insights into As and rice. Further, we develop an understanding of WRKY TF gene family and its regulation in rice. To date, studies on the role of WRKY TFs under As stressed rice are lacking. This area needs to be explored more so that this gene family can be utilized as an effective genetic tool that can break the As cycle to develop low or As free rice cultivar.


Assuntos
Arsênio , Oryza , Humanos , Oryza/genética , Oryza/metabolismo , Fatores de Transcrição/metabolismo , Arsênio/toxicidade , Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico/genética , Regulação da Expressão Gênica de Plantas/genética , Filogenia
11.
Curr Microbiol ; 79(8): 234, 2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35767115

RESUMO

Ralstonia solanacearum, a soil-borne and seed-borne plant pathogenic bacterium, causes bacterial wilt to several important crop plants causing substantial economic losses. To provide population information on this pathogen for developing effective control strategies, Rep-PCR was used to analyze the genetic variation of 18 representative isolates of R. solanacearum collected in Bangladesh. Phenotypic analyses revealed that all eighteen isolates belong to biotype 3 with wide diversity in aggressiveness on eggplant, tomato, and chili. Rep-PCR studies utilizing the REP, ERIC, and BOXIR primers showed a wide variation at the genetic level among the R. solanacearum isolates used in this study. Dendrogram constructed using REP, ERIC, and BOXIR primers based on banding patterns implied that R. solanacearum isolates were genetically diversified and distributed in four clusters at 83%, 80%, and 63% similarity index, respectively. The genetic relationship assayed by rep-PCR highlighted a wide range of genetic variation but no relation among geographical origin, aggressiveness, and phylogenetic groups of R. solanacearum isolates. These results conceded that other molecular markers related to virulence gene(s) might reveal the complex relationship among geographical origin, aggressiveness, and phylogenetic groups.


Assuntos
Ralstonia solanacearum , Solanum lycopersicum , Bangladesh , Primers do DNA , Variação Genética , Solanum lycopersicum/microbiologia , Filogenia , Doenças das Plantas/microbiologia , Plantas , Reação em Cadeia da Polimerase , Ralstonia solanacearum/genética , Verduras
12.
Molecules ; 27(9)2022 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-35566099

RESUMO

Objective: The present study aimed to develop and optimize esomeprazole loaded proniosomes (EZL-PNs) to improve bioavailability and therapeutic efficacy. Method: EZL-PNs formulation was developed by slurry method and optimized by 33 box-Bhekhen statistical design software. Span 60 (surfactant), cholesterol, EZL concentration were taken as independent variables and their effects were evaluated on vesicle size (nm), entrapment efficiency (%, EE) and drug release (%, DR). Furthermore, optimized EZL-PNs (EZL-PNs-opt) formulation was evaluated for ex vivo permeation, pharmacokinetic and ulcer protection activity. Result: The EZL-PNs-opt formulation showed 616 ± 13.21 nm of vesicle size, and 81.21 ± 2.35% of EE. EZL-PNs-opt exhibited negative zeta potential and spherical confirmed scanning electron microscopy. EZL-PNs-opt showed sustained release of EZL (95.07 ± 2.10% in 12 h) than pure EZL dispersion. The ex-vivo gut permeation result exhibited a significantly (p < 0.05) enhanced flux than pure EZL. The in vivo results revealed 4.02-fold enhancement in bioavailability and 61.65% protection in ulcer than pure EZL dispersion (43.82%). Conclusion: Our findings revealed that EZL-PNs formulation could be an alternative delivery system of EZL to enhance oral bioavailability and antiulcer activity.


Assuntos
Esomeprazol , Úlcera , Administração Cutânea , Disponibilidade Biológica , Portadores de Fármacos , Liberação Controlada de Fármacos , Esomeprazol/farmacologia , Humanos , Tamanho da Partícula
13.
Molecules ; 27(13)2022 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-35807270

RESUMO

The aim of the study was to conduct phytochemical and pharmacological investigations of Wrightia coccinea (Roxb. ex Hornem.) Sims via several in vitro, in vivo, and in silico models. A total of four compounds were identified and isolated from the methanol extract of the bark and the methanol extract of the seed pulp of W. coccinea through successive chromatographic techniques and were characterized as 3ß-acetyloxy-olean-12-en-28-ol (1), wrightiadione (2), 22ß-hydroxylupeol (3), and ß-sitosterol (4) by spectroscopic analysis. The aqueous fraction of the bark and chloroform fraction of the fruits provided the most potent antioxidant capacity (IC50 = 7.22 and 4.5 µg/mL, respectively) in DPPH free radical scavenging assay compared with the standard ascorbic acid (IC50 = 17.45 µg/mL). The methanol bark extract and the methanol fruit coat extract exerted anti-diarrheal activity by inhibiting 74.55 ± 0.67% and 77.78 ± 1.5% (mean ± SEM) of the diarrheal episode in mice, respectively, after four hours of loading the samples. In the hypoglycemic test, the methanol bark extract and the methanol fruit coat extract (400 mg/kg) produced a significant (p < 0.05) reduction in the blood glucose level in mice. Both doses of the plant extracts (200 mg/kg and 400 mg/kg) used in the study induced a significant (p < 0.05) increase in pain reaction time. The in vitro and in vivo findings were supported by the computational studies. The isolated compounds exhibited higher binding affinity compared with the standard drugs towards the active binding sites of glutathione reductase, epidermal growth factor receptor (EGFR), kappa opioid receptor, glucose transporter 3 (GLUT 3), Mu opioid receptor, and cyclooxygenase 2 (COX-2) proteins due to their potent antioxidant, cytotoxic, anti-diarrheal, hypoglycemic, and central and peripheral analgesic properties, respectively. The current findings concluded that W. coccinea might be a potential natural source for managing oxidative stress, diarrhea, hyperglycemia, and pain. Further studies are warranted for extensively phytochemical screening and establishing exact mechanisms of action.


Assuntos
Antioxidantes , Apocynaceae , Analgésicos/química , Animais , Antidiarreicos/química , Antioxidantes/química , Diarreia/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Metanol/análise , Camundongos , Dor/tratamento farmacológico , Casca de Planta/química , Extratos Vegetais/química
14.
Molecules ; 27(24)2022 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-36557843

RESUMO

Diabetes mellitus is a life-threatening disorder affecting people of all ages and adversely disrupts their daily functions. Despite the availability of numerous synthetic-antidiabetic medications and insulin, the demand for the development of novel antidiabetic medications is increasing due to the adverse effects and growth of resistance to commercial drugs in the long-term usage. Hence, antidiabetic phytochemicals isolated from fruit plants can be a very nifty option to develop life-saving novel antidiabetic therapeutics, employing several pathways and MoAs (mechanism of actions). This review focuses on the antidiabetic potential of commonly available Bangladeshi fruits and other plant parts, such as seeds, fruit peals, leaves, and roots, along with isolated phytochemicals from these phytosources based on lab findings and mechanism of actions. Several fruits, such as orange, lemon, amla, tamarind, and others, can produce remarkable antidiabetic actions and can be dietary alternatives to antidiabetic therapies. Besides, isolated phytochemicals from these plants, such as swertisin, quercetin, rutin, naringenin, and other prospective phytochemicals, also demonstrated their candidacy for further exploration to be established as antidiabetic leads. Thus, it can be considered that fruits are one of the most valuable gifts of plants packed with a wide spectrum of bioactive phytochemicals and are widely consumed as dietary items and medicinal therapies in different civilizations and cultures. This review will provide a better understanding of diabetes management by consuming fruits and other plant parts as well as deliver innovative hints for the researchers to develop novel drugs from these plant parts and/or their phytochemicals.


Assuntos
Frutas , Hipoglicemiantes , Humanos , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Bangladesh , Estudos Prospectivos , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/uso terapêutico , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico
15.
Biophys J ; 120(23): 5196-5206, 2021 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-34748763

RESUMO

Mechanisms that regulate nitric oxide synthase enzymes (NOS) are of interest in biology and medicine. Although NOS catalysis relies on domain motions and is activated by calmodulin (CaM) binding, the relationships are unclear. We used single-molecule fluorescence resonance energy transfer (FRET) spectroscopy to elucidate the conformational states distribution and associated conformational fluctuation dynamics of the two NOS electron transfer domains in an FRET dye-labeled endothelial NOS reductase domain (eNOSr) and to understand how CaM affects the dynamics to regulate catalysis by shaping the spatial and temporal conformational behaviors of eNOSr. In addition, we developed and applied a new imaging approach capable of recording three-dimensional FRET efficiency versus time images to characterize the impact on dynamic conformal states of the eNOSr enzyme by the binding of CaM, which identifies clearly that CaM binding generates an extra new open state of eNOSr, resolving more detailed NOS conformational states and their fluctuation dynamics. We identified a new output state that has an extra open conformation that is only populated in the CaM-bound eNOSr. This may reveal the critical role of CaM in triggering NOS activity as it gives conformational flexibility for eNOSr to assume the electron transfer output FMN-heme state. Our results provide a dynamic link to recently reported EM static structure analyses and demonstrate a capable approach in probing and simultaneously analyzing all of the conformational states, their fluctuations, and the fluctuation dynamics for understanding the mechanism of NOS electron transfer, involving electron transfer among FAD, FMN, and heme domains, during nitric oxide synthesis.


Assuntos
Calmodulina , Óxido Nítrico Sintase Tipo III , Calmodulina/metabolismo , Transporte de Elétrons , Heme/metabolismo , Óxido Nítrico , Óxido Nítrico Sintase , Óxido Nítrico Sintase Tipo I/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo
16.
J Biol Chem ; 295(8): 2203-2211, 2020 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-31914408

RESUMO

Production of reactive oxygen species caused by dysregulated endothelial nitric-oxide synthase (eNOS) activity is linked to vascular dysfunction. eNOS is a major target protein of the primary calcium-sensing protein calmodulin. Calmodulin is often modified by the main biomarker of nitroxidative stress, 3-nitrotyrosine (nitroTyr). Despite nitroTyr being an abundant post-translational modification on calmodulin, the mechanistic role of this modification in altering calmodulin function and eNOS activation has not been investigated. Here, using genetic code expansion to site-specifically nitrate calmodulin at its two tyrosine residues, we assessed the effects of these alterations on calcium binding by calmodulin and on binding and activation of eNOS. We found that nitroTyr-calmodulin retains affinity for eNOS under resting physiological calcium concentrations. Results from in vitro eNOS assays with calmodulin nitrated at Tyr-99 revealed that this nitration reduces nitric-oxide production and increases eNOS decoupling compared with WT calmodulin. In contrast, calmodulin nitrated at Tyr-138 produced more nitric oxide and did so more efficiently than WT calmodulin. These results indicate that the nitroTyr post-translational modification, like tyrosine phosphorylation, can impact calmodulin sensitivity for calcium and reveal Tyr site-specific gain or loss of functions for calmodulin-induced eNOS activation.


Assuntos
Cálcio/metabolismo , Calmodulina/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Tirosina/metabolismo , Animais , Bovinos , Extratos Celulares , Fluorescência , Células HEK293 , Humanos , Interferometria , Nitrosação , Ligação Proteica
17.
J Pak Med Assoc ; 71(3): 990-992, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34057959

RESUMO

Core Bereavement Items Scale was translated into Urdu language and validated in Pakistani population through forward-backward procedure. It is a 17-item scale with three subscales, namely Images and Thoughts, Acute Separation, and Grief. A cross-sectional study was commenced on June 10, 2016, and completed by July 2017 as part of a pilot study of PhD research at National Institute of Psychology, Quaid-i-Azam University, Islamabad. Two hundred and sixty (260) participants were selected through a combination of convenience and snowball techniques. Results showed good alpha reliability and item-total correlation ranged from 0.62 to 0.77. Confirmatory factor analysis showed good fit of the model on the data. The findings supported the three-factor solution for the translated version of the CBI. The findings also indicated that females and participants living in nuclear family system report more severe bereavement. CBI Urdu version can be used as a valid and reliable measure for the assessment of bereavement intensity in Urdu speaking population anywhere in the world.


Assuntos
Luto , Cônjuges , Estudos Transversais , Feminino , Pesar , Humanos , Idioma , Paquistão , Pais , Projetos Piloto , Psicometria , Reprodutibilidade dos Testes
18.
J Biol Chem ; 294(35): 12880-12891, 2019 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-31311859

RESUMO

The enzyme soluble guanylyl cyclase (sGC) is a heterodimer composed of an α subunit and a heme-containing ß subunit. It participates in signaling by generating cGMP in response to nitric oxide (NO). Heme insertion into the ß1 subunit of sGC (sGCß) is critical for function, and heat shock protein 90 (HSP90) associates with heme-free sGCß (apo-sGCß) to drive its heme insertion. Here, we tested the accuracy and relevance of a modeled apo-sGCß-HSP90 complex by constructing sGCß variants predicted to have an impaired interaction with HSP90. Using site-directed mutagenesis, purified recombinant proteins, mammalian cell expression, and fluorescence approaches, we found that (i) three regions in apo-sGCß predicted by the model mediate direct complex formation with HSP90 both in vitro and in mammalian cells; (ii) such HSP90 complex formation directly correlates with the extent of heme insertion into apo-sGCß and with cyclase activity; and (iii) apo-sGCß mutants possessing an HSP90-binding defect instead bind to sGCα in cells and form inactive, heme-free sGC heterodimers. Our findings uncover the molecular features of the cellular apo-sGCß-HSP90 complex and reveal its dual importance in enabling heme insertion while preventing inactive heterodimer formation during sGC maturation.


Assuntos
Proteínas de Choque Térmico HSP90/metabolismo , Guanilil Ciclase Solúvel/metabolismo , Animais , Células COS , Bovinos , Células Cultivadas , Chlorocebus aethiops , Humanos
19.
Saudi Pharm J ; 28(12): 1777-1790, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33424267

RESUMO

Millettia peguensis, popular for its ethnopharmacological uses, was employed to evaluate its different pharmacological properties in this study. The analgesic studies of the plant have been performed by acetic acid-induced writhing and formalin-induced licking tests respectively, whereas the antidiarrheal experiment was done by castor oil-induced diarrheal test. Besides, antioxidant, cytotoxic, antimicrobial, thrombolytic evaluations were performed by DPPH scavenging with phenol content determination, brine shrimp lethality, disc diffusion and clot lysis methods respectively. Moreover, in silico study of the phytoconstituents was carried out by molecular docking and ADME/T analysis. The methanol extract of Millettia peguensis (MEMP) revealed significant biological activity in the analgesic and antidiarrheal test (p < 0.001) compared to the standards. Antioxidant assay displayed promising IC50 values (15.96 µg/mL) with the total phenol content (65.27 ± 1.24 mg GAE/g). In the cytotoxicity study, the LC50 value was found to be 1.094 µg/mL. Besides, MEMP was highly sensitive to the bacteria but less liable to clot lysis. Furthermore, phytoconstituents exposed potential binding affinity towards the selected receptors, whereas the ADME/T properties indicated the drug likeliness of the plant. The outcomes of these findings suggest the therapeutic potential of this plant against pain, diarrhea, inflammation, and tissue toxicity.

20.
J Biol Chem ; 293(12): 4545-4554, 2018 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-29414777

RESUMO

NO synthase (NOS) enzymes perform interdomain electron transfer reactions during catalysis that may rely on complementary charge interactions at domain-domain interfaces. Guided by our previous results and a computer-generated domain-docking model, we assessed the importance of cross-domain charge interactions in the FMN-to-heme electron transfer in neuronal NOS (nNOS). We reversed the charge of three residues (Glu-762, Glu-816, and Glu-819) that form an electronegative triad on the FMN domain and then individually reversed the charges of three electropositive residues (Lys-423, Lys-620, and Lys-660) on the oxygenase domain (NOSoxy), to potentially restore a cross-domain charge interaction with the triad, but in reversed polarity. Charge reversal of the triad completely eliminated heme reduction and NO synthesis in nNOS. These functions were partly restored by the charge reversal at oxygenase residue Lys-423, but not at Lys-620 or Lys-660. Full recovery of heme reduction was probably muted by an accompanying change in FMN midpoint potential that made electron transfer to the heme thermodynamically unfavorable. Our results provide direct evidence that cross-domain charge pairing is required for the FMN-to-heme electron transfer in nNOS. The unique ability of charge reversal at position 423 to rescue function indicates that it participates in an essential cross-domain charge interaction with the FMN domain triad. This supports our domain-docking model and suggests that it may depict a productive electron transfer complex formed during nNOS catalysis.


Assuntos
Elétrons , Heme/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Óxido Nítrico/metabolismo , Animais , Catálise , Citocromos c/metabolismo , Transporte de Elétrons , Mononucleotídeo de Flavina/metabolismo , Cinética , Modelos Moleculares , Mutação , Óxido Nítrico Sintase Tipo I/química , Óxido Nítrico Sintase Tipo I/genética , Oxirredução , Domínios Proteicos , Ratos
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