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1.
BMC Pediatr ; 24(1): 460, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39026197

RESUMO

BACKGROUND: Mild hypoxic ischemic encephalopathy is associated with sub optimal cognition and learning difficulties at school age. Although whole-body hypothermia reduces death and disability after moderate or severe encephalopathy in high-income countries, the safety and efficacy of hypothermia in mild encephalopathy is not known. The cooling in mild encephalopathy (COMET) trial will examine if whole-body hypothermia improves cognitive development of neonates with mild encephalopathy. METHODS: The COMET trial is a phase III multicentre open label two-arm randomised controlled trial with masked outcome assessments. A total of 426 neonates with mild encephalopathy will be recruited from 50 to 60 NHS hospitals over 2 ½ years following parental consent. The neonates will be randomised to 72 h of whole-body hypothermia (33.5 ± 0.5 C) or normothermia (37.0 ± 0.5 C) within six hours or age. Prior to the recruitment front line clinical staff will be trained and certified on expanded modified Sarnat staging for encephalopathy. The neurological assessment of all screened and recruited cases will be video recorded and centrally assessed for quality assurance. If recruitment occurs at a non-cooling centre, neonates in both arms will be transferred to a cooling centre for continued care, after randomisation. All neonates will have continuous amplitude integrated electroencephalography (aEEG) at least for the first 48 h to monitor for seizures. Predefined safety outcomes will be documented, and data collected to assess resource utilization of health care. A central team masked to trial group allocation will assess neurodevelopmental outcomes at 2 years of age. The primary outcome is mean difference in composite cognitive scores on Bayley scales of Infant and Toddler development 4th Edition. DISCUSSION: The COMET trial will establish the safety and efficacy of whole-body hypothermia for mild hypoxic ischaemic encephalopathy and inform national and international guidelines in high income countries. It will also provide an economic assessment of whole-body hypothermia therapy for mild encephalopathy in the NHS on cost-effectiveness grounds. TRIAL REGISTRATION NUMBER: NCT05889507 June 5, 2023.


Assuntos
Hipotermia Induzida , Hipóxia-Isquemia Encefálica , Humanos , Hipotermia Induzida/métodos , Recém-Nascido , Hipóxia-Isquemia Encefálica/terapia , Estudos Multicêntricos como Assunto , Ensaios Clínicos Fase III como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto
2.
Int J Biol Macromol ; 264(Pt 2): 130698, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38458296

RESUMO

In the pursuit of eco-friendly and sustainable materials, polyglycerol diacid polymers hold immense promise for drug delivery compared to those derived from fossil fuels. Harnessing this potential, we aimed to prepare nanoparticles (NPs) derived from sustainable polymers, loaded with ferulic acid (FA), a natural polyphenolic compound known for its shielding effect against liver-damaging agents, including carbon tetrachloride (CCl4). Glycerol was esterified with renewable monomers, such as succinic acid, adipic acid, and/or FA, resulting in the creation of a novel class of polyglycerol diacid polymers. Characterization via Fourier-transform infrared spectroscopy and nuclear magnetic resonance confirmed the successful synthesis of these polymers with <7 % residual monomers. FA-loaded NPs were fabricated using the newly synthesized polymers. To further augment their potential, the NPs were coated with chitosan. The chitosan-coated NPs boasted an optimal PS of 290 ± 5.03 nm, showing superior physical stability, and a commendable EE% of 58.79 ± 0.43%w/v. The cytotoxicity was examined on fibroblast cells using the SRB assay. In-vivo experiments employing a CCl4-induced liver injury model yielded compelling evidence of the heightened hepatoprotective effects conferred by chitosan-coated particles. This demonstrates the benefits of incorporating sustainable polymers into innovative composites for efficient drug delivery, indicating their potential for creating versatile platforms for various therapeutic applications.


Assuntos
Quitosana , Ácidos Cumáricos , Nanopartículas , Glicerol/química , Quitosana/química , Polímeros/química , Nanopartículas/química , Portadores de Fármacos/química , Tamanho da Partícula
4.
Dermatol Ther ; 35(6): e15476, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35357060

RESUMO

The aim of this meta-analysis is to evaluate the safety of dupilumab use in the management of atopic dermatitis (AD) during the current pandemic regarding the risk and the hazards of COVID-19 infection. Seven databases (Google Scholar, Web of Science, Scopus, Virtual Health Library, PubMed, System for Information on Gray Literature in Europe, and The New York Academy of Medicine) were searched for eligible studies from inception until November 24, 2021. The quality of evidence was rated using the National Institute of Health and the Joanna Briggs Institute Critical Appraisal tool. Meta-analysis was performed when the outcome is presented ≥2 studies. A total of 12 papers including 1611 AD patients were included in the study. The prevalence of COVID-19 in AD treated with dupilumab was 3.2% (95% confidence interval [CI]: 1.7-5.8). COVID-19 symptoms were reported by five patients who were presented with one or more of the following symptoms (fatigue, loss of taste and smell, runny nose, conjunctivitis, gastrointestinal symptoms, fever, cough, and dyspnea). Only three cases of COVID-19 were hospitalized with a prevalence of 4.5%, while no patients with COVID-19 died. Dupilumab is safe regarding the risk and the hazards of COVID-19 in AD patients. Thus, based on these results continuation of dupilumab in AD patients is recommended, since dupilumab seems to be safe and crucial for a better disease outcome.


Assuntos
Tratamento Farmacológico da COVID-19 , Dermatite Atópica , Anticorpos Monoclonais Humanizados/efeitos adversos , Dermatite Atópica/induzido quimicamente , Dermatite Atópica/diagnóstico , Dermatite Atópica/tratamento farmacológico , Humanos , Índice de Gravidade de Doença , Resultado do Tratamento
5.
Epidemiol Health ; 43: e2021045, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34265893

RESUMO

OBJECTIVES: This study aimed to examine the prevalence of psychiatric disorders among Egyptian healthcare workers (HCWs) during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: Six databases were searched for relevant papers. The quality of the selected articles was measured using the National Institute of Health quality assessment tool. We used a fixed-effects model when there was no heterogeneity and a random-effects model when there was heterogeneity. RESULTS: After screening 197 records, 10 studies were ultimately included. Anxiety was the most commonly reported psychiatric disorder among HCWs, with a prevalence of 71.8% (95% confidence interval [CI], 49.4 to 86.9), followed by stress (66.6%; 95% CI, 47.6 to 81.3), depression (65.5%; 95% CI, 46.9 to 80.3), and insomnia (57.9%; 95% CI, 45.9 to 69.0). As measured using the 21-item Depression, Anxiety, and Stress Scale, the most common level of severity was moderate for depression (22.5%; 95% CI, 19.8 to 25.5) and stress (14.5%; 95% CI, 8.8 to 22.9), while high-severity anxiety was more common than other levels of severity (28.2%; 95% CI, 3.8 to 79.6). CONCLUSIONS: The COVID-19 pandemic has had a negative effect on Egyptian HCWs' psychological well-being. More psychological support and preventive measures should be implemented to prevent the further development of psychiatric illness among physicians and other HCWs.


Assuntos
COVID-19 , Distúrbios do Início e da Manutenção do Sono , Ansiedade/epidemiologia , Depressão/epidemiologia , Egito/epidemiologia , Pessoal de Saúde , Humanos , Pandemias , SARS-CoV-2
6.
Expert Rev Respir Med ; 15(12): 1589-1595, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34018900

RESUMO

Background: Sarcoidosis is multisystem inflammatory granulomatosis that can potentially affect any organ of the human body. We aimed to estimate the prevalence of diabetes mellitus (DM) in sarcoidosis patients and determine the association between sarcoidosis and DM.Method: All relevant articles reporting the prevalence of DM in sarcoidosis published until September 19th, 2020, were retrieved from ten electronic databases. We used the random effect model to perform the meta-analysis.Results: After screening 2,122 records, we included 19 studies (n = 18,686,162). The prevalence of DM in sarcoidosis patients was 12.7% (95% CI 10-16.1). The prevalence was highest in North America with 21.3% (13.5-31.8), followed by Europe 10.4 (7.9-13.7) and Asia 10% (1.8-39.7). Sarcoidosis patients had higher rates of DM compared to controls (OR 1.75; 95% CI 1.49-2.05). Sensitivity analysis, after removing the largest weighted study, did not reveal any effect on the significance of the results (OR 1.73; 95% CI 1.33-2.25).Conclusion: The prevalence of DM in sarcoidosis is considerably high, with increased odds of DM in sarcoidosis compared to healthy controls. Further research with a wide range of confounders is required to confirm the association of sarcoidosis with DM.


Assuntos
Diabetes Mellitus , Sarcoidose , Bases de Dados Factuais , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiologia , Europa (Continente) , Humanos , Prevalência , Sarcoidose/diagnóstico , Sarcoidose/epidemiologia
7.
Biochem Pharmacol ; 184: 114359, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33285109

RESUMO

Poly-ADP-ribose polymerase (PARP) inhibitors are active against cells and tumors with defects in homology-directed repair as a result of synthetic lethality. PARP inhibitors (PARPi) have been suggested to act by either catalytic inhibition or by PARP localization in chromatin. In this study, we treat BRCA1 mutant cells derived from a patient with triple negative breast cancer and control cells for three weeks with veliparib, a PARPi, to determine if treatment with this drug induces increased levels of mutations and/or an inflammatory response. We show that long-term treatment with PARPi induces an inflammatory response in HCC1937 BRCA1 mutant cells. The levels of chromatin-bound PARP1 in the BRCA1 mutant cells correlate with significant upregulation of inflammatory genes and activation of the cyclic GMP-AMP synthase (cGAS)/signaling effector stimulator of interferon genes (STING pathway). In contrast, an increased mutational load is induced in BRCA1-complemented cells treated with a PARPi. Our results suggest that long-term PARP inhibitor treatment may prime both BRCA1 mutant and wild-type tumors for positive responses to immune checkpoint blockade, but by different underlying mechanisms.


Assuntos
Proteína BRCA1/genética , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/imunologia , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Antígeno B7-H1/metabolismo , Proteína BRCA1/imunologia , Benzimidazóis/farmacologia , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Citocinas/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/imunologia , Humanos , Fatores Imunológicos/farmacologia , Inflamação/tratamento farmacológico , Inflamação/genética , Proteínas de Membrana/metabolismo , Mutação
8.
J Biol Chem ; 295(27): 9012-9020, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32385112

RESUMO

Eukaryotic DNA polymerase ß (Pol ß) plays an important role in cellular DNA repair, as it fills short gaps in dsDNA that result from removal of damaged bases. Since defects in DNA repair may lead to cancer and genetic instabilities, Pol ß has been extensively studied, especially its mechanisms for substrate binding and a fidelity-related conformational change referred to as "fingers closing." Here, we applied single-molecule FRET to measure distance changes associated with DNA binding and prechemistry fingers movement of human Pol ß. First, using a doubly labeled DNA construct, we show that Pol ß bends the gapped DNA substrate less than indicated by previously reported crystal structures. Second, using acceptor-labeled Pol ß and donor-labeled DNA, we visualized dynamic fingers closing in single Pol ß-DNA complexes upon addition of complementary nucleotides and derived rates of conformational changes. We further found that, while incorrect nucleotides are quickly rejected, they nonetheless stabilize the polymerase-DNA complex, suggesting that Pol ß, when bound to a lesion, has a strong commitment to nucleotide incorporation and thus repair. In summary, the observation and quantification of fingers movement in human Pol ß reported here provide new insights into the delicate mechanisms of prechemistry nucleotide selection.


Assuntos
DNA Polimerase beta/metabolismo , DNA/metabolismo , Cristalografia por Raios X/métodos , DNA Polimerase I/química , DNA Polimerase beta/fisiologia , Reparo do DNA , Replicação do DNA , Proteínas de Ligação a DNA/metabolismo , Transferência Ressonante de Energia de Fluorescência/métodos , Humanos , Cinética , Modelos Moleculares , Conformação de Ácido Nucleico , Nucleotídeos/metabolismo , Conformação Proteica , Especificidade por Substrato/fisiologia
9.
Nucleic Acids Res ; 47(22): 11839-11849, 2019 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-31732732

RESUMO

DNA polymerase ß (pol ß) selects the correct deoxyribonucleoside triphosphate for incorporation into the DNA polymer. Mistakes made by pol ß lead to mutations, some of which occur within specific sequence contexts to generate mutation hotspots. The adenomatous polyposis coli (APC) gene is mutated within specific sequence contexts in colorectal carcinomas but the underlying mechanism is not fully understood. In previous work, we demonstrated that a somatic colon cancer variant of pol ß, K289M, misincorporates deoxynucleotides at significantly increased frequencies over wild-type pol ß within a mutation hotspot that is present several times within the APC gene. Kinetic studies provide evidence that the rate-determining step of pol ß catalysis is phosphodiester bond formation and suggest that substrate selection is governed at this step. Remarkably, we show that, unlike WT, a pre-catalytic step in the K289M pol ß kinetic pathway becomes slower than phosphodiester bond formation with the APC DNA sequence but not with a different DNA substrate. Based on our studies, we propose that pre-catalytic conformational changes are of critical importance for DNA polymerase fidelity within specific DNA sequence contexts.


Assuntos
DNA Polimerase beta/metabolismo , Replicação do DNA/fisiologia , Polipose Adenomatosa do Colo/genética , Substituição de Aminoácidos/genética , Sequência de Bases , Catálise , Neoplasias do Colo/genética , DNA Polimerase beta/química , DNA Polimerase beta/genética , Ligação de Hidrogênio , Cinética , Lisina/genética , Modelos Moleculares , Mutagênese Sítio-Dirigida , Estrutura Secundária de Proteína , Especificidade por Substrato , Moldes Genéticos
10.
Reumatologia ; 57(4): 239-242, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31548751

RESUMO

The authors report a female case of systemic lupus erythematosus (SLE) that was diagnosed as Wilson's disease (WD) when neurological manifestations were evident three years after the first admission. The brain imaging studies showed bilateral symmetrical basal ganglia involvement, slit lamp examination revealed Kayser-Fleischer ring of the cornea, and 24-hour urinary copper and serum ceruloplasmin also confirmed the diagnosis. The patient also had hemolytic anemia and hypoparathyroidism, which are rare presenting features of WD. SLE may be associated with WD, and presence of neurological, behavioral, or liver function abnormalities should raise the suspicion, even without apparent features of WD.

11.
Nucleic Acids Res ; 46(20): 10740-10756, 2018 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-30239932

RESUMO

DNA polymerase ß (pol ß) fills single nucleotide gaps in DNA during base excision repair and non-homologous end-joining. Pol ß must select the correct nucleotide from among a pool of four nucleotides with similar structures and properties in order to maintain genomic stability during DNA repair. Here, we use a combination of X-ray crystallography, fluorescence resonance energy transfer and nuclear magnetic resonance to show that pol ß's ability to access the appropriate conformations both before and upon binding to nucleotide substrates is integral to its fidelity. Importantly, we also demonstrate that the inability of the I260Q mutator variant of pol ß to properly navigate this conformational landscape results in error-prone DNA synthesis. Our work reveals that precatalytic conformational rearrangements themselves are an important underlying mechanism of substrate selection by DNA pol ß.


Assuntos
Códon sem Sentido , DNA Polimerase beta/genética , Replicação do DNA/genética , DNA/química , Instabilidade Genômica/genética , Conformação de Ácido Nucleico , Substituição de Aminoácidos/genética , Catálise , Cristalografia por Raios X , DNA/metabolismo , DNA Polimerase beta/química , DNA Polimerase beta/metabolismo , Reparo do DNA/genética , Transferência Ressonante de Energia de Fluorescência , Ácido Glutâmico/genética , Isoenzimas/química , Isoenzimas/genética , Isoenzimas/metabolismo , Isoleucina/genética , Modelos Moleculares , Nucleotídeos/química , Nucleotídeos/metabolismo , Ligação Proteica , Especificidade por Substrato/genética , Moldes Genéticos
12.
J Biol Chem ; 293(39): 15084-15094, 2018 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-30068550

RESUMO

DNA polymerase ß (Pol ß) is essential for maintaining genomic integrity. During short-patch base excision repair (BER), Pol ß incorporates a nucleotide into a single-gapped DNA substrate. Pol ß may also function in long-patch BER, where the DNA substrate consists of larger gap sizes or 5'-modified downstream DNA. We have recently shown that Pol ß fills small gaps in DNA during microhomology-mediated end-joining as part of a process that increases genomic diversity. Our previous results with single-nucleotide gapped DNA show that Pol ß undergoes two pre-catalytic conformational changes upon binding to the correct nucleotide substrate. Here we use FRET to investigate nucleotide incorporation of Pol ß with various DNA substrates. The results show that increasing the gap size influences the fingers closing step by increasing its reverse rate. However, the 5'-phosphate group has a more significant effect. The absence of the 5'-phosphate decreases the DNA binding affinity of Pol ß and results in a conformationally more open binary complex. Moreover, upon addition of the correct nucleotide in the absence of 5'-phosphate, a slow fingers closing step is observed. Interestingly, either increasing the gap size or removing the 5'-phosphate group results in loss of the noncovalent step. Together, these results suggest that the character of the DNA substrate impacts the nature and rates of pre-catalytic conformational changes of Pol ß. Our results also indicate that conformational changes are important for the fidelity of DNA synthesis by Pol ß.


Assuntos
DNA Polimerase beta/química , Replicação do DNA/genética , DNA/biossíntese , Nucleotídeos/genética , Catálise , Cristalografia por Raios X , DNA/química , DNA/genética , Reparo do DNA por Junção de Extremidades/genética , DNA Polimerase beta/genética , Reparo do DNA/genética , Humanos , Cinética , Nucleotídeos/química , Especificidade por Substrato
13.
Biochemistry ; 56(41): 5550-5559, 2017 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-28945359

RESUMO

DNA polymerases synthesize new DNA during DNA replication and repair, and their ability to do so faithfully is essential to maintaining genomic integrity. DNA polymerase ß (Pol ß) functions in base excision repair to fill in single-nucleotide gaps, and variants of Pol ß have been associated with cancer. Specifically, the E288K Pol ß variant has been found in colon tumors and has been shown to display sequence-specific mutator activity. To probe the mechanism that may underlie E288K's loss of fidelity, a fluorescence resonance energy transfer system that utilizes a fluorophore on the fingers domain of Pol ß and a quencher on the DNA substrate was employed. Our results show that E288K utilizes an overall mechanism similar to that of wild type (WT) Pol ß when incorporating correct dNTP. However, when inserting the correct dNTP, E288K exhibits a faster rate of closing of the fingers domain combined with a slower rate of nucleotide release compared to those of WT Pol ß. We also detect enzyme closure upon mixing with the incorrect dNTP for E288K but not WT Pol ß. Taken together, our results suggest that E288K Pol ß incorporates all dNTPs more readily than WT because of an inherent defect that results in rapid isomerization of dNTPs within its active site. Structural modeling implies that this inherent defect is due to interaction of E288K with DNA, resulting in a stable closed enzyme structure.


Assuntos
Neoplasias do Colo/enzimologia , DNA Polimerase beta/metabolismo , Reparo do DNA , Replicação do DNA , DNA/metabolismo , Modelos Moleculares , Mutação , Substituição de Aminoácidos , Biocatálise , Neoplasias do Colo/genética , DNA/química , DNA Polimerase beta/química , DNA Polimerase beta/genética , Estabilidade Enzimática , Corantes Fluorescentes/química , Humanos , Cinética , Mutagênese Sítio-Dirigida , Naftalenossulfonatos/química , Proteínas de Neoplasias/química , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Redobramento de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Especificidade por Substrato , p-Dimetilaminoazobenzeno/análogos & derivados , p-Dimetilaminoazobenzeno/química
14.
Mol Pharmacol ; 87(2): 197-206, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25411367

RESUMO

Some inverse agonists of cannabinoid receptor type 1 (CB1) have been demonstrated to be anorectic antiobesity drug candidates. However, the first generation of CB1 inverse agonists, represented by rimonabant (SR141716A), otenabant, and taranabant, are centrally active, with a high level of psychiatric side effects. Hence, the discovery of CB1 inverse agonists with a chemical scaffold distinct from these holds promise for developing peripherally active CB1 inverse agonists with fewer side effects. We generated a new CB1 inverse agonist, (4-(bis(4-fluorophenyl)methyl)piperazin-1-yl)(cyclohexyl)methanone hydrochloride (LDK1229), from the class of benzhydryl piperazine analogs. This compound binds to CB1 more selectively than cannabinoid receptor type 2, with a Ki value of 220 nM. Comparable CB1 binding was also observed by analogs 1-[bis(4-fluorophenyl)methyl]-4-cinnamylpiperazine dihydrochloride (LDK1203) and 1-[bis(4-fluorophenyl)methyl]-4-tosylpiperazine hydrochloride (LDK1222), which differed by the substitution on the piperazine ring where the piperazine of LDK1203 and LDK1222 are substituted by an alkyl group and a tosyl group, respectively. LDK1229 exhibits efficacy comparable with SR141716A in antagonizing the basal G protein coupling activity of CB1, as indicated by a reduction in guanosine 5'-O-(3-thio)triphosphate binding. Consistent with inverse agonist behavior, increased cell surface localization of CB1 upon treatment with LDK1229 was also observed. Although docking and mutational analysis showed that LDK1229 forms similar interactions with the receptor as SR141716A does, the benzhydryl piperazine scaffold is structurally distinct from the first-generation CB1 inverse agonists. It offers new opportunities for developing novel CB1 inverse agonists through the optimization of molecular properties, such as the polar surface area and hydrophilicity, to reduce the central activity observed with SR141716A.


Assuntos
Compostos Benzidrílicos/farmacologia , Canabinoides/farmacologia , Agonismo Inverso de Drogas , Piperazinas/farmacologia , Receptor CB1 de Canabinoide/agonistas , Animais , Compostos Benzidrílicos/química , Canabinoides/química , Bovinos , Células HEK293 , Humanos , Piperazina , Piperazinas/química , Ligação Proteica/fisiologia , Estrutura Secundária de Proteína , Receptor CB1 de Canabinoide/metabolismo
15.
Front Cell Neurosci ; 8: 337, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25374508

RESUMO

The etiology of neuroinflammation is complex and comprises multifactorial, involving both genetic and environmental factors during which diverse genetic and epigenetic modulations are implicated. Curcumin (Cur) and valproic acid (VPA), histone deacetylase 1 inhibitor, have neuroprotective effects. The present study was designed with an aim to investigate the ability of co-treatment of both compounds (Cur or VPA, 200 mg/kg) for 4 weeks to augment neuroprotection and enhance brain recovery from intra-peritoneal injection of (250 µg/kg) lipopolysaccharide-stimulated neuroinflammatory condition on rat brain cortex. Cortex activation and the effects of combined treatment and production of proinflammatory mediators, cyclooxygenase-2 (COX-2), APE1, and nitric oxide/inducible nitric oxide synthase (iNOS) were investigated. Neuroinflammation development was assessed by histological analyses and by investigating associated indices [ß-secretase (BACE1), amyloid protein precursor (APP), presenilin (PSEN-1), and PSEN-2)]. Furthermore we measured the expression profile of lethal-7 (let-7) miRNAs members a, b, c, e, and f in all groups, a highly abundant regulator of gene expression in the CNS. Protein and mRNA levels of neuroinflammation markers COX-2, BACE1, APP, and iNOS were also attenuated by combined therapy. On the other hand, assessment of the indicated five let-7 members, showed distinct expression profile pattern in the different groups. Let-7 a, b, and c disappeared in the induced group, an effect that was partially suppressed by co-addition of either Cur or VPA. These data suggest that the combined treatment induced significantly the expression of the five members when compared to rats treated with Cur or VPA only as well as to self-recovery group, which indicates a possible benefit from the synergistic effect of Cur-VPA combination as therapeutic agents for neuroinflammation and its associated disorders. The mechanism elucidated here highlights the particular drug-induced expression profile of let-7 family as new targets for future pharmacological development.

16.
J Med Chem ; 56(20): 7965-75, 2013 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-24053617

RESUMO

The cannabinoid CB1 receptor is involved in complex physiological functions. The discovery of CB1 allosteric modulators generates new opportunities for drug discovery targeting the pharmacologically important CB1 receptor. 5-Chloro-3-ethyl-N-(4-(piperidin-1-yl)phenethyl)-1H-indole-2-carboxamide (ORG27569; 1) represents a new class of indole-2-carboxamides that exhibit allostery of CB1. To better understand the SAR, a group of indole-2-carboxamide analogues were synthesized and assessed for allostery of the CB1 receptor. We found that within the structure of indole-2-carboxamides, the presence of the indole ring is preferred for maintaining the modulator's high binding affinity for the allosteric site but not for generating allostery on the orthosteric site. However, the C3 substituents of the indole-2-carboxamides significantly impact the allostery of the ligand. A robust CB1 allosteric modulator 5-chloro-N-(4-(dimethylamino)phenethyl)-3-pentyl-1H-indole-2-carboxamide (11j) was identified. It showed an equilibrium dissociation constant (KB) of 167.3 nM with a markedly high binding cooperativity factor (α = 16.55) and potent antagonism of agonist-induced GTPγS binding.


Assuntos
Indóis/química , Indóis/farmacologia , Receptor CB1 de Canabinoide/metabolismo , Regulação Alostérica/efeitos dos fármacos , Ligação Competitiva , Células HEK293 , Humanos , Indóis/síntese química , Cinética , Modelos Químicos , Estrutura Molecular , Piperidinas/química , Piperidinas/farmacologia , Ensaio Radioligante , Receptor CB1 de Canabinoide/genética , Relação Estrutura-Atividade
17.
J Biol Chem ; 288(14): 9790-9800, 2013 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-23449980

RESUMO

The cannabinoid receptor 1 (CB1) is a G protein-coupled receptor primarily expressed in brain tissue that has been implicated in several disease states. CB1 allosteric compounds, such as ORG27569, offer enormous potential as drugs over orthosteric ligands, but their mechanistic, structural, and downstream effects upon receptor binding have not been established. Previously, we showed that ORG27569 enhances agonist binding affinity to CB1 but inhibits G protein-dependent agonist signaling efficacy in HEK293 cells and rat brain expressing the CB1 receptor (Ahn, K. H., Mahmoud, M. M., and Kendall, D. A. (2012) J. Biol. Chem. 287, 12070-12082). Here, we identify the mediators of CB1 receptor internalization and ORG27569-induced G protein-independent signaling. Using siRNA technology, we elucidate an ORG27569-induced signaling mechanism for CB1 wherein ß-arrestin 1 mediates short term signaling to ERK1/2 with a peak at 5 min and other upstream kinase components including MEK1/2 and c-Src. Consistent with these findings, we demonstrate co-localization of CB1-GFP with red fluorescent protein-ß-arrestin 1 upon ORG27569 treatment using confocal microscopy. In contrast, we show the critical role of ß-arrestin 2 in CB1 receptor internalization upon treatment with CP55940 (agonist) or treatment with ORG27569. These results demonstrate for the first time the involvement of ß-arrestin in CB1-biased signaling by a CB1 allosteric modulator and also define the differential role of the two ß-arrestin isoforms in CB1 signaling and internalization.


Assuntos
Arrestinas/metabolismo , Indóis/farmacologia , Piperidinas/farmacologia , Receptor CB1 de Canabinoide/metabolismo , Sítio Alostérico , Animais , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Células HEK293 , Humanos , Proteínas Luminescentes/metabolismo , Microscopia Confocal/métodos , Conformação Proteica , Isoformas de Proteínas , Estrutura Secundária de Proteína , RNA Interferente Pequeno/metabolismo , Ratos , Transdução de Sinais , beta-Arrestina 1 , beta-Arrestina 2 , beta-Arrestinas , Proteína Vermelha Fluorescente
18.
J Neurochem ; 124(5): 584-9, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23205875

RESUMO

Allosteric modulation of G-protein coupled receptors (GPCRs) represents a novel approach for fine-tuning GPCR functions. The cannabinoid CB1 receptor, a GPCR associated with the CNS, has been implicated in the treatment of drug addiction, pain, and appetite disorders. We report here the synthesis and pharmacological characterization of two indole-2-carboxamides:5-chloro-3-ethyl-1-methyl-N-(4-(piperidin-1-yl)phenethyl)-1H-indole-2-carboxamide (ICAM-a) and 5-chloro-3-pentyl-N-(4-(piperidin-1-yl)phenethyl)-1H-indole-2-carboxamide (ICAM-b). Although both ICAM-a and ICAM-b enhanced CP55, 940 binding, ICAM-b exhibited the strongest positive cooperativity thus far demonstrated for enhancing agonist binding to the CB1 receptor. Although it displayed negative modulatory effects on G-protein coupling to CB1, ICAM-b induced ß-arrestin-mediated downstream activation of extracellular signal-regulated kinase (ERK) signaling. These results indicate that this compound represents a novel class of CB1 ligands that produce biased signaling via CB1.


Assuntos
Indóis/farmacologia , Piperidinas/farmacologia , Receptor CB1 de Canabinoide/química , Receptor CB1 de Canabinoide/metabolismo , Transdução de Sinais/efeitos dos fármacos , Regulação Alostérica/efeitos dos fármacos , Células HEK293 , Humanos , Immunoblotting , Indóis/química , Indóis/metabolismo , Ligantes , Piperidinas/química , Piperidinas/metabolismo , Ligação Proteica
19.
J Biol Chem ; 287(15): 12070-82, 2012 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-22343625

RESUMO

The cannabinoid receptor 1 (CB1), a member of the class A G protein-coupled receptor family, is expressed in brain tissue where agonist stimulation primarily activates the pertussis toxin-sensitive inhibitory G protein (G(i)). Ligands such as CP55940 ((1R,3R,4R)-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-4-(3- hydroxypropyl)cyclohexan-1-ol) and Δ(9)-tetrahydrocannabinol are orthosteric agonists for the receptor, bind the conventional binding pocket, and trigger G(i)-mediated effects including inhibition of adenylate cyclase. ORG27569 (5-chloro-3-ethyl-1H-indole-2-carboxylic acid [2-(4-piperidin-1-yl-phenyl)ethyl]amide) has been identified as an allosteric modulator that displays positive cooperativity for CP55940 binding to CB1 yet acts as an antagonist of G protein coupling. To examine this apparent conundrum, we used the wild-type CB1 and two mutants, T210A and T210I (D'Antona, A. M., Ahn, K. H., and Kendall, D. A. (2006) Biochemistry 45, 5606-5617), which collectively cover a spectrum of receptor states from inactive to partially active to more fully constitutively active. Using these receptors, we demonstrated that ORG27569 induces a CB1 receptor state that is characterized by enhanced agonist affinity and decreased inverse agonist affinity consistent with an active conformation. Also consistent with this conformation, the impact of ORG27569 binding was most dramatic on the inactive T210A receptor and less pronounced on the already active T210I receptor. Although ORG27569 antagonized CP55940-induced guanosine 5'-3-O-(thio)triphosphate binding, which is indicative of G protein coupling inhibition in a concentration-dependent manner, the ORG27569-induced conformational change of the CB1 receptor led to cellular internalization and downstream activation of ERK signaling, providing the first case of allosteric ligand-biased signaling via CB1. ORG27569-induced ERK phosphorylation persisted even after pertussis toxin treatment to abrogate G(i) and occurs in HEK293 and neuronal cells.


Assuntos
Endocitose/efeitos dos fármacos , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Indóis/farmacologia , Sistema de Sinalização das MAP Quinases , Piperidinas/farmacologia , Receptor CB1 de Canabinoide/metabolismo , Regulação Alostérica , Animais , Cicloexanóis/farmacologia , Sinergismo Farmacológico , Ativação Enzimática , Guanosina 5'-O-(3-Tiotrifosfato)/farmacologia , Células HEK293 , Hipocampo/citologia , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Toxina Pertussis/farmacologia , Fosforilação , Ligação Proteica , Estrutura Secundária de Proteína , Pirazóis/farmacologia , Ratos , Receptor CB1 de Canabinoide/agonistas , Receptor CB1 de Canabinoide/química , Rimonabanto
20.
J Med Virol ; 79(5): 469-73, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17385672

RESUMO

Human immunodeficiency virus (HIV) infection and the development of the acquired immunodeficiency syndrome (AIDS) are increasing at an alarming rate especially in the sub-Saharan region. Pregnant women susceptible to HIV and its transmission to the fetus provide a unique opportunity for implementing preventive strategy against HIV infection of newborn babies. During the period of August-December 2005 a cross-sectional study was conducted at the Fath-Elrahman Elbashir antenatal clinic, Khartoum Teaching Hospital, to investigate pregnant women's basic knowledge and attitude toward HIV and mother to child transmission as well as voluntary counseling and testing. Pre-tested structured questionnaires were given to antenatal attendants by professional counselors. Their basic socio-demographic and obstetric characteristics were obtained. Respondents' knowledge about HIV and mother to child transmission were tested. In addition, their willingness toward HIV testing was also reported. Out of the 1,005 women investigated, 79% had basic knowledge about HIV. Those who were resident in Khartoum and whose age was > or =26.1 years and their education level was secondary and above were found to be more knowledgeable about HIV. More than half of respondents were aware of mother to child transmission. Older (> or =26.1 years), educated, and working mothers were found to be more knowledgeable about mother to child transmission. Willingness to undergo the test was demonstrated in 72.8% of respondents. However, only 30.3% had the test done. Older women, primigravidae, and Muslims have higher acceptance of voluntary counseling and testing. There is a need to extend the voluntary counseling and testing program in all antenatal clinics. In addition, there is a need to increase the level of education and raise health awareness about HIV and mother to child transmission.


Assuntos
Infecções por HIV/prevenção & controle , HIV , Conhecimentos, Atitudes e Prática em Saúde , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Complicações Infecciosas na Gravidez/prevenção & controle , Cuidado Pré-Natal/estatística & dados numéricos , Adulto , Aconselhamento , Estudos Transversais , Feminino , Humanos , Gravidez , Gestantes , Sudão , Inquéritos e Questionários
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