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1.
Naunyn Schmiedebergs Arch Pharmacol ; 397(3): 1647-1658, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-37704773

RESUMO

Berberine (BBR), a bioactive compound isolated from Coptidis Rhizoma, possesses diverse pharmacological activities including anti-bacterial, anti-inflammatory, antitumor, hypolipidemic, and anti-diabetic. However, its role as an anti-diabetic agent in animal models of dexamethasone (Dex)-induced diabetes remains unknown. Studies have shown that natural compounds including aloe, caper, cinnamon, cocoa, green and black tea, and turmeric can be used for treating Type 2 diabetes mellitus (DM). Compared to conventional drugs, natural compounds have less side effects and are easily available. Herein, we studied the anti-diabetic effects of BBR in a mice model of Dex-induced diabetes. HepG2 cell line was used for glucose release and glycogen synthesis studies. Cell proliferation was measured by methylthiotetrazole (MTT) assay. For animal studies, mice were treated with Dex (2 mg/kg, i.m.) for 30 days and effect of BBR at the doses 100, 200, and 500 mg/kg (p.o.) was analyzed. Glucose, insulin, and pyruvate tests were performed for evaluating the development of the diabetic model. Echo MRI was performed to assess the fat mass. Further, to elucidate the mechanism of action of BBR, mRNA expression of genes regulating gluconeogenesis, glucose uptake, and glycolysis was analyzed. In vitro BBR had no impact on cell viability up to a concentration of 50 µM. Moreover, BBR suppressed the hepatic glucose release and improved glucose tolerance in HepG2 cells. In vivo, BBR improved glucose homeostasis in diabetic mice as evidenced by enhanced glucose clearance, increased glycolysis, elevated glucose uptake, and decreased gluconeogenesis. Further, Dex treatment increased the total fat mass in mice, which was ameliorated by BBR treatment. BBR improves glucose tolerance by increasing glucose clearance, inhibiting hepatic glucose release, and decreasing obesity. Thus, BBR may become a potential therapeutic agent for treating glucocorticoid-induced diabetes and obesity in the future.


Assuntos
Berberina , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Hiperglicemia , Camundongos , Animais , Berberina/farmacologia , Berberina/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Glucocorticoides/farmacologia , Glucocorticoides/uso terapêutico , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Hiperglicemia/induzido quimicamente , Hiperglicemia/tratamento farmacológico , Glucose/metabolismo , Anti-Inflamatórios/uso terapêutico , Obesidade/tratamento farmacológico
2.
Addict Behav ; 148: 107868, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37774527

RESUMO

Prepulse inhibition (PPI) is a measure of sensorimotor filtering thought to shield the processing of initial weaker auditory stimuli from interruption by a later startle response. Previous studies have shown smoking withdrawal to have a negative impact on sensorimotor filtering, particularly in individuals with psychopathology. Because tobacco use may alleviate sensory and sensorimotor filtering deficits, we examined whether smoking withdrawal-induced changes in PPI were associated with maintenance of smoking abstinence in trauma-exposed individuals with and without PTSD who were attempting to quit smoking. Thirty-eight individuals (n = 24 with current or past PTSD; 14 trauma-exposed healthy controls) made an acute biochemically-verified smoking cessation attempt supported by 8 days of contingency management (CM) and cognitive behavioral therapy (CBT) for smoking. Participants completed a PPI task at the pre-quit baseline, 2 days post-quit, and 5 days post-quit. Post-quit changes in PPI were compared between those who remained abstinent for the first 8-days of the quit attempt and those who lapsed back to smoking. PPI changes induced by biochemically-verified smoking abstinence were associated with maintenance of abstinence across the 8-day CM/CBT-supported quit attempt. As compared to those who maintained tobacco abstinence, participants who lapsed to smoking had significantly lower PPI at 2 and 5 days post-quit relative to baseline. Thus, among trauma-exposed individuals, decreases in PPI during acute smoking cessation supported by CM/CBT are associated with lapse back to smoking. Interventions that improve PPI during early smoking abstinence may facilitate smoking cessation among such individuals who are at high risk for chronic, refractory tobacco use.


Assuntos
Abandono do Hábito de Fumar , Tabagismo , Humanos , Fumar/terapia , Fumar/psicologia , Fumar Tabaco , Abandono do Hábito de Fumar/psicologia , Tabagismo/psicologia , Produtos do Tabaco
3.
Metab Brain Dis ; 37(7): 2521-2532, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35895244

RESUMO

Genistein (GE) or 4',5,7-trihydroxyflavone, a plant derived isoflavone, is a biologically active compound having several beneficial properties. Studies showed that GE possesses anti-neoplastic, anti-tumor, anti-helminthic, anti-oxidant, and anti-inflammatory activities. Herein, we investigated the neuroprotective effects of GE in a mouse model of hypoxia-induced amnesia. Mice were exposed to hypoxic conditions (10% O2) in a designated hypoxia chamber and co-treated with GE (10, 20, or 30 mg/kg) for 4 weeks. Following this, behavioral tests were performed to evaluate memory performance. We assessed microglial activation in the hippocampus, amygdala, and pre-frontal cortex (PFC) regions by evaluating the Iba-1 and GFAP transcript levels, and MIP-1ß, Cox-2, and IL6 protein levels. Apoptosis was assessed by evaluating Bax, BAD, and Bcl-2 mRNA levels, and caspase-3 activity. To uncover the underlying molecular mechanism, we evaluated the levels of Nrf2, HO-1, and NQO1 in different brain regions of mice from all groups. Results showed that hypoxia-exposed mice have reduced performance in the behavioral tests and GE treatment enhanced the memory performance in hypoxia-exposed mice. Moreover, hypoxia-exposed mice showed increased expression of microglial activation markers and enhanced apoptosis in the hippocampus, amygdala, and PFC. GE treatment suppressed microglial activation and prevented apoptosis in the brain of hypoxia-exposed mice. Furthermore, hypoxia-exposure reduced the expression of Nrf2, NQO1, and HO-1 while GE treatment ameliorated this decrease in different regions of hypoxia-exposed mice brain. In conclusion, GE prevents cognitive dysfunction by suppressing microglial activation and inhibiting apoptosis in the hypoxia-exposed mice brain.


Assuntos
Genisteína , Fármacos Neuroprotetores , Animais , Camundongos , Genisteína/farmacologia , Fator 2 Relacionado a NF-E2/metabolismo , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Interleucina-6/metabolismo , Antioxidantes/farmacologia , Caspase 3/metabolismo , Microglia/metabolismo , Ciclo-Oxigenase 2/metabolismo , Quimiocina CCL4/metabolismo , Proteína X Associada a bcl-2/metabolismo , Amnésia/induzido quimicamente , Apoptose , Encéfalo/metabolismo , Hipóxia/complicações , Hipóxia/tratamento farmacológico , Modelos Animais de Doenças , Anti-Inflamatórios/farmacologia , RNA Mensageiro
4.
ACS Chem Neurosci ; 13(8): 1263-1272, 2022 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-35385250

RESUMO

Parkinson's disease (PD) is the second most common devastating neurodegenerative disorder. Presently used therapies for PD have severe side effects and are limited to only temporary improvement. Therefore, a new therapeutic approach to treat PD urgently needs to be developed. α-Lactalbumin, the most abundant milk protein in camel milk, has been attributed to various medicinal properties. This study intended to investigate the neuroprotective efficacy of the camel α-lactalbumin and oleic acid (CLOA) complex. One mechanism postulated to underlie neuroprotection by the CLOA complex is the induction of silent information regulatory protein (SIRT1). SIRT1 is known to be involved in several pathological and physiological processes, and it has been suggested that SIRT1 plays a protective role in PD. Oxidative stress, inflammation, mitochondrial dysfunction, and apoptosis are involved in PD pathogenesis. Our results revealed that SIRT1 inhibits oxidative stress by maintaining HIF-1α in a deacetylated state. SIRT1 upregulates the expression of FOXO3a and HSF-1, thus inhibiting apoptosis and maintaining the homeostasis of cellular proteins. Increased SIRT1 expression reduces the levels of TNF-α, IL-6, and IL-8, which in turn inhibits neuroinflammation. In addition to SIRT1, the CLOA complex also enhances the expression of survivin and leptin and promotes the survival of neuroblastoma cells. Altogether, our results suggest that the CLOA complex might be a novel therapeutic molecule that could ameliorate neuronal cell damage in PD.


Assuntos
Fármacos Neuroprotetores , Doença de Parkinson , Animais , Camelus/metabolismo , Lactalbumina/metabolismo , Lactalbumina/farmacologia , Lactalbumina/uso terapêutico , Neuroproteção , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Ácido Oleico/farmacologia , Ácido Oleico/uso terapêutico , Estresse Oxidativo , Doença de Parkinson/tratamento farmacológico , Rotenona , Sirtuína 1/metabolismo , Sirtuína 1/farmacologia , Sirtuína 1/uso terapêutico
5.
Int J Mol Epidemiol Genet ; 12(2): 24-34, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34093968

RESUMO

Asthma is a complex genetic disease. Vitamin D and vitamin D receptor (VDR) gene polymorphisms are involved in asthma pathogenesis. However, accurate inflammatory mechanisms and their role in VDR gene polymorphisms are unclear. The objective of this study was to investigate the association of VDR gene polymorphisms, ApaI, FokI, TaqI, and BsmI with asthma as compared to controls. Children (age 5-15 years) with a history of respiratory symptoms (wheeze, shortness of breath and chest tightness) were recruited as cases. Age matched children admitted with central nervous system disorders (encephalitis/seizures) without any respiratory complaints were recruited as controls after parental consent. Children with a clinical diagnosis of cystic fibrosis, congenital heart disease and whose parents did not consent for participation in the study were excluded. VDR gene polymorphisms were genotyped using PCR-RFLP method. One hundred and sixty asthmatics and one hundred controls were enrolled in this study. Mean age of the cases was 103.29±32.7 months and controls 94.24±30.52 months. Children with heterozygous (AC) genotype [OR=1.83, 95% CI=1.01-3.32, p=0.046] of ApaI polymorphism were found to be associated with the risk of asthma. Our findings suggest that ApaI polymorphism of VDR gene may contribute to asthma susceptibility among children.

6.
J Periodontal Implant Sci ; 51(3): 199-212, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34114383

RESUMO

PURPOSE: This randomized clinical placebo-controlled trial was conducted to evaluate the effectiveness of Lactobacillus reuteri as a probiotic in guided pocket recolonization (GPR) for the treatment of chronic periodontitis (CP) adjunctive to scaling and root planing (SRP). METHODS: Forty-eight CP patients were randomly assigned to 3 treatment groups: group 1 (SRP+placebo), group 2 (SRP+single application of probiotic), and group 3 (SRP+incremental application of probiotic). Clinical parameters were evaluated at baseline and at 8, 12, and 24 weeks, whereas biochemical parameters were measured at baseline and 12 weeks. RESULTS: At 24 weeks, the probing pocket depth and clinical attachment level improved in all 3 groups from baseline with no significant intergroup differences; however, a statistically significant difference was observed in localized plaque and gingival scores between groups 1 and 3 (P<0.05). At 12 weeks, matrix metalloproteinase-8 (MMP-8), nitric oxide (NO), and gingipains-R (Rgps) levels improved in all 3 groups, with statistically significant differences between groups 1 and 3 for MMP-8 and NO (P<0.05), but no difference for Rgps levels. CONCLUSIONS: Within its limitations, the results of this study show that incremental 3-time application of L. reuteri as a probiotic led to improvements in clinical and biochemical parameters. This protocol can be a useful adjunct to SRP in the non-surgical management of CP. TRIAL REGISTRATION: Clinical Trials Registry - India Identifier: CTRI/2017/03/008231.

7.
Int J Mol Epidemiol Genet ; 12(1): 1-8, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33859782

RESUMO

Community-acquired pneumonia (CAP) is a leading cause of death in children under five years of age globally. Currently, the vitamin D receptor (VDR) gene is an emerging factor that regulates inflammatory pathways that may alter the response to infections and possibly modify the outcome of CAP. The objective of this study was to investigate the association of VDR gene polymorphisms ApaI, FokI, TaqI, BsmI with CAP in children aged 2-59 months. Hospitalized children aged (2-59 months) with WHO-defined CAP were included as cases after parental consent. Age-matched healthy controls were recruited from the immunization clinic of the hospital within one week of the recruitment of the case. Children with a clinical diagnosis of cystic fibrosis and congenital heart disease were excluded. Four VDR gene polymorphisms, ApaI, FokI, TaqI, BsmI were genotyped by using PCR-RFLP. From Oct-2016 to Oct-2019, 160 cases (34.37% females) and 160 controls (47.5% females) were recruited. Mean age of the cases was 26.30±23.10 months and controls 25.93±15.99 months. In FokI (rs2228570 polymorphism, heterozygous genotype (CT) [OR=2.06, 95% CI=1.25-3.39, P=0.00] and mutant allele (T) [OR=1.45, 95% CI=1.06-2.00, P=0.02] were found to be associated with the risk of CAP. In VDR gene, FokI polymorphism predisposes to CAP in Indian children.

8.
Neurotox Res ; 39(4): 1123-1133, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33740236

RESUMO

Genistein (GE), a plant-derived isoflavone, is a polyphenolic non-steroidal compound. Studies showed that GE possesses anti-cancer, anti-inflammatory, anti-microbial, anti-oxidant, and anti-apoptotic activities. However, the neuroprotective role of GE in amnesia has not been studied. This study aimed to evaluate the anti-amnesic potential of GE in a mice model of hypoxia-induced amnesia and to understand the underlying mechanism. Mice were exposed to hypoxia (10% O2) and administered vehicle or GE (10, 20, 30 mg/kg) orally for 28 days. Thereafter, Morris water maze (MWM), novel object recognition (NOR), and passive avoidance task (PAT) were performed to evaluate cognitive behavior. Next, we performed biochemical tests and gene expression analysis to uncover the mechanism underlying GE mode of action. Our results showed that GE-treatment ameliorated hypoxia-induced cognitive dysfunctions in mice. Further, GE-treatment suppressed the oxidative stress in the hippocampus of amnesic mice as evidenced by reduced lipid peroxidation, reduced nitrite and ROS levels, and increased levels of reduced glutathione (GSH) and increased total antioxidant capacity. GE treatment reduced the expression of pro-inflammatory cytokines TNFα, IL1ß, IL6, and MCP-1 and increased the expression of anti-inflammatory cytokine IL10 in the hippocampus of amnesic mice. Finally, GE treatment enhanced the expression of neuroprotective genes including BDNF, CREB, CBP, and IGF1 in the hippocampus of amnesic mice. Altogether, our results showed that GE treatment prevents hypoxia-induced cognitive dysfunction in mice by reducing oxidative stress and suppressing neuroinflammation while increasing the expression of neuroprotective genes in the hippocampus.


Assuntos
Disfunção Cognitiva/prevenção & controle , Genisteína/uso terapêutico , Hipocampo/efeitos dos fármacos , Hipóxia/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Estresse Oxidativo/efeitos dos fármacos , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Aprendizagem da Esquiva/fisiologia , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/metabolismo , Relação Dose-Resposta a Droga , Genisteína/farmacologia , Hipocampo/metabolismo , Hipóxia/complicações , Hipóxia/metabolismo , Inflamação/metabolismo , Inflamação/prevenção & controle , Masculino , Camundongos , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/fisiologia , Fitoestrógenos/farmacologia , Fitoestrógenos/uso terapêutico
9.
Metab Brain Dis ; 35(3): 517-525, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31834548

RESUMO

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by loss of dopaminergic neurons in substantia nigra region and the presence of α-synuclein aggregates in the striatum and surrounding areas of brain. Evidences suggest that neuroinflammation plays a role in the progression of PD. We examined the neuro-protective effects of Bacopa monnieri (BM) in regulating neuroinflammation. Administration of BM suppressed the level of pro-inflammatory cytokines, decreased the levels of α-synuclein, and reduced reactive oxygen species (ROS) generation in PD animal model. Pre-treatment of BM showed more prominent results as compare to co- and post-treatment. Results suggest that Bacopa can limit inflammation in the different areas of brain, thus, offers a promising source of novel therapeutics for the treatment of many CNS disorders.


Assuntos
Bacopa , Fármacos Neuroprotetores/uso terapêutico , Estresse Oxidativo/efeitos dos fármacos , Doença de Parkinson Secundária/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Animais , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Quimiocina CCL4/metabolismo , Modelos Animais de Doenças , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Masculino , Fármacos Neuroprotetores/farmacologia , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/metabolismo , Extratos Vegetais/farmacologia , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Rotenona , Substância Negra/efeitos dos fármacos , Substância Negra/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , alfa-Sinucleína/metabolismo
10.
Indian J Otolaryngol Head Neck Surg ; 71(Suppl 2): 1639-1651, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31750230

RESUMO

The worldwide population of diabetic patients is increasing alarmingly with India claiming number one position. It causes irreversible damage to cochlear hair cells, vestibular apparatus, visual pathway, nephrons, nerves, if not checked in time. A total of 188 patients of diabetes mellitus were included in this prospective study. The patients underwent routine anamnesis, hearing handicap inventory and dizziness handicap inventory assessment along with clinical examination for audiological, vestibular, neurological and ophthalmological (fundoscopy) status. In our study a sensorineural hearing loss, retinopathy, neuropathy, vestibulopathy was seen in diabetic patients.

11.
J Chem Neuroanat ; 85: 50-59, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28711564

RESUMO

Parkinson's disease (PD) is one of the most common neurodegenerative disease found in the aging population. Currently, many studies are being conducted to find a suitable and effective cure for PD, with an emphasis on the use of herbal plants. In this study, the neuroprotective effects of estrogen was evaluated in the 1-methyl-4-phe-nyl-1,2,3,6-tetrahydropyridine (MPTP) model of PD with cognitive deficit and compared to Levodopa (LD), a well reported neuroprotective agent used for treating PD. Twenty-four Swiss albino mice were randomly divided into four groups: Control, MPTP, MPTP+LD and MPTP+estrogen. The behavioral recovery in both LD and estrogen treated mice were investigated using the rotarod, foot printing, narrow beam walking test and hanging tests. Non-motor behavioral recovery in both LD and estrogen treated were investigated using the Y-maze and Morris water maze. Furthermore, we performed the biochemical test i.e. catalase, lipid and nitrite in prefrontal cortex as well as nigrostriatal region of mouse brain. We also performed the acetylcholine esterase activity in prefrontal cortex and nigrostriatal region of mice brain. The recovery of dopamine neurons in the substantia nigra (SN) region was estimated by immunostaining of tyrosine hydroxylase (TH). Estrogen treatment restored all the deficits induced by MPTP more effectively than levodopa. Estrogen treatment recovered the number of TH-positive cells in both the SN region. Treatment with Estrogen significantly increased the levels of catalase, decreased the level of lipid and nitite in both region SN as well as prefrontal cortex region. Notably, the effect of estrogen was greater than that elicited by levodopa. Acetylcholine esterase activity was significantly increased in MPTP and it was found to be decreased by the treatment of estrogen as well as levodopa, although decrease in the activity was highly significant in estrogen treated group. Our result suggested that estrogen treatment significantly reduced the MPTP induced neurotoxicity as evident by decrease in oxidative damage, physiological abnormalities and immunohistochemical changes in the Parkinsonian mouse with cognitive deficit as compared to levodopa treatment.


Assuntos
Transtornos Cognitivos/tratamento farmacológico , Estradiol/uso terapêutico , Levodopa/uso terapêutico , Intoxicação por MPTP/tratamento farmacológico , Aprendizagem em Labirinto/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Acetilcolinesterase/metabolismo , Animais , Transtornos Cognitivos/metabolismo , Transtornos Cognitivos/patologia , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/patologia , Estradiol/farmacologia , Levodopa/farmacologia , Intoxicação por MPTP/metabolismo , Intoxicação por MPTP/patologia , Camundongos , Fármacos Neuroprotetores/farmacologia , Ovariectomia , Substância Negra/efeitos dos fármacos , Substância Negra/metabolismo , Substância Negra/patologia , Tirosina 3-Mono-Oxigenase/metabolismo
12.
Laryngoscope ; 127(3): E100-E106, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27577998

RESUMO

OBJECTIVE: An attempt is made to analyze the molecular behavior of juvenile nasopharyngeal angiofibroma (JNA). STUDY DESIGN: Case Series METHODS: Quantification of mRNAs expression was undertaken through real-time polymerase chain reaction in JNA (9-24) samples for VEGF-A, basic fibroblast growth factor (b-FGF), platelet-derived growth factor PDGF-A, KIT proto-oncogene receptor tyrosine kinase (c-Kit), Avian myelomatosis viral oncogene homolog (c-Myc), Harvey rat sarcoma viral oncogene homolog (H-Ras), tumor suppressor gene TP53, and androgen receptor and interleukin 6 (IL-6). The ß-catenin expression was evaluated by western blot in 16 samples. Nasal polyp was taken as control. RESULTS: A significantly increased (P < 0.01) expression of c-myc, VEGFA, bFGF, PDGFA, c-kit, and TP53 was seen, along with enhanced expression of ß-catenin. A massive enhancement of H-Ras expression was seen for the first time. Androgen receptor expression was no different, whereas IL-6 despite showing upregulation trend was not significant. CONCLUSION: The enhanced expressions of various markers suggest their potential role in JNA. Although the biological significance of c-kit, c-myc, and one of the novel markers H-Ras has yet to be defined, their significant expression may have a therapeutic importance. LEVEL OF EVIDENCE: NA. Laryngoscope, 127:E100-E106, 2017.


Assuntos
Angiofibroma/genética , Angiofibroma/patologia , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/patologia , Adolescente , Angiofibroma/epidemiologia , Biópsia por Agulha , Criança , Estudos de Coortes , Feminino , Fator 2 de Crescimento de Fibroblastos/genética , Fator 2 de Crescimento de Fibroblastos/metabolismo , Marcadores Genéticos , Estudo de Associação Genômica Ampla , Humanos , Imuno-Histoquímica , Índia/epidemiologia , Masculino , Neoplasias Nasofaríngeas/epidemiologia , Fator de Crescimento Derivado de Plaquetas/genética , Fator de Crescimento Derivado de Plaquetas/metabolismo , Proto-Oncogene Mas , Reação em Cadeia da Polimerase em Tempo Real/métodos , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Sensibilidade e Especificidade , Adulto Jovem
13.
J Virol ; 86(23): 12686-94, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22973024

RESUMO

Antibodies to epitopes in the E2 protein of hepatitis C virus (HCV) reduce the viral infectivity in vivo and in vitro. However, the virus can persist in patients in the presence of neutralizing antibodies. In this study, we generated a panel of monoclonal antibodies that bound specifically to the region between residues 427 and 446 of the E2 protein of HCV genotype 1a, and we examined their capacity to neutralize HCV in a cell culture system. Of the four monoclonal antibodies described here, two were able to neutralize the virus in a genotype 1a-specific manner. The other two failed to neutralize the virus. Moreover, one of the nonneutralizing antibodies could interfere with the neutralizing activity of a chimpanzee polyclonal antibody at E2 residues 412 to 426, as it did with an HCV-specific immune globulin preparation, which was derived from the pooled plasma of chronic hepatitis C patients. Mapping the epitope-paratope contact interfaces revealed that these functionally distinct antibodies shared binding specificity for key amino acid residues, including W(437), L(438), L(441), and F(442), within the same epitope of the E2 protein. These data suggest that the effectiveness of antibody-mediated neutralization of HCV could be deduced from the interplay between an antibody and a specific set of amino acid residues. Further understanding of the molecular mechanisms of antibody-mediated neutralization and nonneutralization should provide insights for designing a vaccine to control HCV infection in vivo.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Hepacivirus/imunologia , Proteínas do Envelope Viral/imunologia , Sequência de Aminoácidos/genética , Animais , Anticorpos Monoclonais/biossíntese , Anticorpos Neutralizantes/biossíntese , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Epitopos/genética , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Testes de Neutralização , Pan troglodytes
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