Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
1.
Biochim Biophys Acta Mol Basis Dis ; 1870(2): 166986, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38092158

RESUMO

Oligodendrocytes, crucial myelinating glia in the central nervous system, play a vital role in maintaining axonal integrity and facilitating efficient nerve impulse conduction. The degradation of myelin in oligodendrocytes has been implicated in Alzheimer's disease (AD) and cognitive dysfunction. Interestingly, individuals with Type 2 Diabetes (T2D) have a significantly higher likelihood of developing cognitive impairment, possibly due to insulin resistance and glucose toxicity within the central nervous system (CNS). However, the precise relationship between these two disorders remains elusive. Our study proposes a potential link between T2D and AD, involving Cdk5-mediated breakdown of oligodendrocyte myelin and neuroinflammation. In the context of T2D, glucose toxicity in oligodendrocytes leads to heightened Cdk5 kinase activity and cPLA2 hyperactivation, resulting in chronic inflammation and myelin deterioration. This myelin breakdown in oligodendrocytes is thought to contribute to the development of AD and cognitive dysfunction. Notably, the administration of a Cdk5 inhibitor (TFP5) effectively alleviates neuroinflammation and myelin degradation. Moreover, our findings demonstrate heightened activity of Cdk5, cPLA2, and phospho-cPLA2 levels in the brain of a mouse model with Type 2 Diabetes (T2D). Hence, our findings suggest that targeting Cdk5 could be a promising therapeutic strategy to counteract AD pathogenesis in T2D-related conditions.


Assuntos
Doença de Alzheimer , Diabetes Mellitus Tipo 2 , Animais , Camundongos , Doença de Alzheimer/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Glucose/metabolismo , Bainha de Mielina/metabolismo , Doenças Neuroinflamatórias , Oligodendroglia/metabolismo , Fosfolipases A2 Citosólicas/metabolismo
2.
Neuropeptides ; 93: 102245, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35461022

RESUMO

AIM: Gestational diabetes mellitus (GDM) might predispose the mothers to depression. Studies have reported the role of biomarkers either in GDM or depression, but very few have examined them in GDM with depression. The present study profiled the circulating levels of brain-derived neurotrophic factor (BDNF), Beta Endorphin (BE) and nesfatin-1 in women with GDM (with and without depression). METHODS: 160 pregnant women at 24-28 weeks of pregnancy (NGT/GDM with & without depression, n = 40 each) were randomly selected from the ongoing STRiDE (STratification of Risk of Diabetes in Early pregnancy) study. Depression score was derived using PHQ-9 questionnaire and ELISA was used to quantify the biomarkers. RESULTS: Circulatory levels of BDNF, BE and nesfatin-1 were lower in GDM women with or without depression compared to NGT without depression, however, nesfatin-1 levels were higher in NGT with depression. Notably, GDM with depression had the lowest levels of BDNF and BE. Both BDNF and BE levels were negatively correlated with depression, 1 h and 2 h plasma glucose. Regression analysis confirmed that each standard deviation decreases in BDNF and BE were independently associated with higher odds of GDM with or without depression even after adjusting for potential confounders. CONCLUSION: Our study has identified altered levels of a panel of neurobiological biomarkers (BDNF/BE/nesfatin-1) in those with combined GDM and depression. BDNF/BE could be potential biomarkers to assess the higher risk of coexisting depression and GDM.


Assuntos
Diabetes Gestacional , Povo Asiático , Biomarcadores , Fator Neurotrófico Derivado do Encéfalo , Depressão , Feminino , Humanos , Gravidez
3.
Ann Indian Acad Neurol ; 24(4): 586-588, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34728955

RESUMO

Outcomes of pallidal stimulation in KMT2B dystonia have been infrequently reported prospectively. We report the six-month outcomes of bilateral GPi DBS in an Asian Indian patient with early-onset generalized dystonia associated with a novel heterozygous variant in the KMT2B gene.

4.
Comput Struct Biotechnol J ; 18: 2347-2356, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32994893

RESUMO

ATP7A is a critical copper transporter involved in Menkes Disease, Occipital horn Syndrome and X-linked distal spinal muscular atrophy type 3 which are X linked genetic disorders. These are rare diseases and their genetic epidemiology of the diseases is unknown. A number of genetic variants in the genes have been reported in published literature as well as databases, however, understanding the pathogenicity of variants and genetic epidemiology requires the data to be compiled in a unified format. To this end, we systematically compiled genetic variants from published literature and datasets. Each of the variants were systematically evaluated for evidences with respect to their pathogenicity and classified as per the American College of Medical Genetics and the Association of Molecular Pathologists (ACMG-AMP) guidelines into Pathogenic, Likely Pathogenic, Benign, Likely Benign and Variants of Uncertain Significance. Additional integrative analysis of population genomic datasets provides insights into the genetic epidemiology of the disease through estimation of carrier frequencies in global populations. To deliver a mechanistic explanation for the pathogenicity of selected variants, we also performed molecular modeling studies. Our modeling studies concluded that the small structural distortions observed in the local structures of the protein may lead to the destabilization of the global structure. To the best of our knowledge, ATP7A Clinical Genetics Resource is one of the most comprehensive compendium of variants in the gene providing clinically relevant annotations in gene.

5.
Asian J Psychiatr ; 42: 24-27, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30947092

RESUMO

INTRODUCTION: Somatization Disorder (SD) is known to cause disability and impact the quality of life due to psychological and somatic distress. Though it is a Common Mental Disorder (CMD), the disorder tends to visit all levels of health care, among which prevalence of SD at tertiary care is 10.1%. AIMS: To estimate current prevalence and its correlates of socio-clinical factors in SD at a quaternary mental health centre (QMHC). METHODS: Total of 422 adult subjects were selected through systematic random sampling at first contact psychiatry outpatient clinic. Subjects were interviewed with Mini International Neuropsychiatric Interview Plus version 5.0.0, Clinical Global Impression Severity Scale and Sheehan Disability Scale. RESULTS: Current prevalence of SD was 5%. Significant correlates are observed with median age of 40.5 years, female, married, <5 years of education, monthly income of <₹ 10,357(85.5%) and lower socioeconomic status (75%). DISCUSSION: There is high prevalence of SD even at QMHC. The higher prevalence among adult population in this setup reflect the impairment of working population which invariably impact on national economy. CONCLUSION: Poverty continues to be a major contributing factor to SD causing double impact on the economy by affecting the working population the most.


Assuntos
Hospitais Psiquiátricos/estatística & dados numéricos , Fatores Socioeconômicos , Transtornos Somatoformes/epidemiologia , Centros Médicos Acadêmicos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Estudos Transversais , Feminino , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Pobreza/estatística & dados numéricos , Prevalência , Fatores Sexuais , Adulto Jovem
6.
J Neuroimmunol ; 323: 125-130, 2018 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-30196825

RESUMO

The etiopathogenesis of Guillain Barré Syndrome (GBS) is inadequately understood. The role of immuno-inflammatory Th17 pathway was examined in GBS patients by genetic, gene expression and biochemical studies. Genotyping of G197A single nucleotide polymorphism within IL17 gene was carried out by PCR-RFLP method in 220 GBS patients. Quantification of gene expression of STAT3 and RORC and estimation of plasma level of IL-17A were carried out in a subset of patients. Significantly increased STAT3 gene expression in lymphocytes and plasma IL-17A levels were observed in GBS patients. This study adds new dimension and reinforces important implications of Th17 pathway in GBS.


Assuntos
Síndrome de Guillain-Barré/sangue , Síndrome de Guillain-Barré/genética , Polimorfismo de Nucleotídeo Único/genética , Transdução de Sinais/fisiologia , Células Th17/metabolismo , Adulto , Estudos de Coortes , Feminino , Síndrome de Guillain-Barré/epidemiologia , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
7.
Artigo em Inglês | MEDLINE | ID: mdl-29770126

RESUMO

Type 2 diabetes mellitus (T2DM) is a metabolic disorder that is characterized by functional defects in glucose metabolism and insulin secretion. Its complex etiology and multifaceted nature have made it difficult to design effective therapies for early diagnosis and treatment. Several lines of evidence indicate that aberrant activation of the unfolded protein response (UPR) in response to endoplasmic reticulum (ER) stress impairs the ß cell's ability to respond to glucose and promotes apoptosis. Elucidating the molecular mechanisms that govern ß cell dysfunction and cell death can help investigators design therapies to halt or prevent the development of T2DM. Early diagnosis of T2DM, however, warrants additionally the identification of potential biomarkers. MicroRNAs (miRNAs) are key regulators of transcriptional processes that modulate various features of insulin signaling, such as insulin sensitivity, glucose tolerance, and insulin secretion. A deeper understanding of how changes in patterns of expression of miRNAs correlate with altered glucose metabolism can enable investigators to develop methods for the early diagnosis and treatment of T2DM. The first part of this review examines how altered expression of specific UPR pathway proteins disrupts ER function and causes ß cell dysfunction, while the second part discusses the potential role of miRNAs in the diagnostic and treatment of T2DM.

8.
BMC Psychiatry ; 18(1): 106, 2018 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-29669557

RESUMO

BACKGROUND: There is emerging evidence that there are shared genetic, environmental and developmental risk factors in psychiatry, that cut across traditional diagnostic boundaries. With this background, the Discovery biology of neuropsychiatric syndromes (DBNS) proposes to recruit patients from five different syndromes (schizophrenia, bipolar disorder, obsessive compulsive disorder, Alzheimer's dementia and substance use disorders), identify those with multiple affected relatives, and invite these families to participate in this study. The families will be assessed: 1) To compare neuro-endophenotype measures between patients, first degree relatives (FDR) and healthy controls., 2) To identify cellular phenotypes which differentiate the groups., 3) To examine the longitudinal course of neuro-endophenotype measures., 4) To identify measures which correlate with outcome, and 5) To create a unified digital database and biorepository. METHODS: The identification of the index participants will occur at well-established specialty clinics. The selected individuals will have a strong family history (with at least another affected FDR) of mental illness. We will also recruit healthy controls without family history of such illness. All recruited individuals (N = 4500) will undergo brief clinical assessments and a blood sample will be drawn for isolation of DNA and peripheral blood mononuclear cells (PBMCs). From among this set, a subset of 1500 individuals (300 families and 300 controls) will be assessed on several additional assessments [detailed clinical assessments, endophenotype measures (neuroimaging- structural and functional, neuropsychology, psychophysics-electroencephalography, functional near infrared spectroscopy, eye movement tracking)], with the intention of conducting repeated measurements every alternate year. PBMCs from this set will be used to generate lymphoblastoid cell lines, and a subset of these would be converted to induced pluripotent stem cell lines and also undergo whole exome sequencing. DISCUSSION: We hope to identify unique and overlapping brain endophenotypes for major psychiatric syndromes. In a proportion of subjects, we expect these neuro-endophenotypes to progress over time and to predict treatment outcome. Similarly, cellular assays could differentiate cell lines derived from such groups. The repository of biomaterials as well as digital datasets of clinical parameters, will serve as a valuable resource for the broader scientific community who wish to address research questions in the area.


Assuntos
Predisposição Genética para Doença , Testes Genéticos/métodos , Leucócitos Mononucleares , Adulto , Transtorno Bipolar/diagnóstico , Eletroencefalografia , Feminino , Variação Genética/genética , Humanos , Masculino , Esquizofrenia/diagnóstico , Transtornos Relacionados ao Uso de Substâncias/fisiopatologia
9.
Sci Rep ; 8(1): 1177, 2018 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-29352128

RESUMO

Cyclin-dependent kinase 5 (Cdk5) is a key neuronal kinase that is upregulated during inflammation, and can subsequently modulate sensitivity to nociceptive stimuli. We conducted an in silico screen for Cdk5 phosphorylation sites within proteins whose expression was enriched in nociceptors and identified the chemo-responsive ion channel Transient Receptor Potential Ankyrin 1 (TRPA1) as a possible Cdk5 substrate. Immunoprecipitated full length TRPA1 was shown to be phosphorylated by Cdk5 and this interaction was blocked by TFP5, an inhibitor that prevents activation of Cdk5. In vitro peptide-based kinase assay revealed that four of six TRPA1 Cdk5 consensus sites acted as substrates for Cdk5, and modeling of the ankyrin repeats disclosed that phosphorylation would occur at characteristic pockets within the (T/S)PLH motifs. Calcium imaging of trigeminal ganglion neurons from genetically engineered mice overexpressing or lacking the Cdk5 activator p35 displayed increased or decreased responsiveness, respectively, to stimulation with the TRPA1 agonist allylisothiocyanate (AITC). AITC-induced chemo-nociceptive behavior was also heightened in vivo in mice overexpressing p35 while being reduced in p35 knockout mice. Our findings demonstrate that TRPA1 is a substrate of Cdk5 and that Cdk5 activity is also able to modulate TRPA1 agonist-induced calcium influx and chemo-nociceptive behavioral responses.


Assuntos
Quinase 5 Dependente de Ciclina/metabolismo , Nociceptividade , Canal de Cátion TRPA1/metabolismo , Animais , Cálcio/metabolismo , Biologia Computacional/métodos , Quinase 5 Dependente de Ciclina/química , Quinase 5 Dependente de Ciclina/genética , Humanos , Camundongos , Camundongos Knockout , Modelos Moleculares , Imagem Molecular , Neurônios/metabolismo , Fosforilação , Conformação Proteica , Especificidade por Substrato , Canal de Cátion TRPA1/química , Canal de Cátion TRPA1/genética , Gânglio Trigeminal/metabolismo
10.
Mol Pain ; 13: 1744806917737205, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28969475

RESUMO

Abstract: Cdk5 is a key neuronal kinase necessary for proper brain development, which has recently been implicated in modulating nociception. Conditional deletion of Cdk5 in pain-sensing neurons attenuates pain responses to heat in both the periphery and orofacial regions. Cdk5 activity is regulated by binding to the activators p35 and p39, both of which possess a cyclin box. Our previous examination of the nociceptive role of the well-characterized Cdk5 activator p35 using mice that either lack or overexpress this regulatory subunit demonstrated that Cdk5/p35 activity affects mechanical, chemical, and thermal nociception. In contrast, the nociceptive role of Cdk5's other less-studied activator p39 is unknown. Here, we report that the knockout of p39 in mice did not affect orofacial and peripheral nociception. The lack of any algesic response to nociceptive stimuli in the p39 knockout mice contrasts with the hypoalgesic effects that result from the deletion of p35. Our data demonstrate different and nonoverlapping roles of Cdk5 activators in the regulation of orofacial as well as peripheral nociception with a crucial role for Cdk5/p35 in pain signaling.


Assuntos
Quinase 5 Dependente de Ciclina/metabolismo , Proteínas do Citoesqueleto/deficiência , Dor Facial/metabolismo , Proteínas Ligadas a Lipídeos/deficiência , Proteínas do Tecido Nervoso/metabolismo , Animais , Quinase 5 Dependente de Ciclina/genética , Dor Facial/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/metabolismo , Percepção da Dor/fisiologia , Fosfotransferases/metabolismo , Sensação/fisiologia , Transdução de Sinais/fisiologia
11.
Indian J Psychol Med ; 39(3): 276-280, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28615760

RESUMO

BACKGROUND: Mobile phone technology is being used worldwide to improve follow-ups in health care. AIM: Aim of the study is to evaluate whether the use of mobile technology will improve or not the follow-up of Indian patients from a community mental health center. MATERIALS AND METHODS: Patients or caregivers having mobile phones and consenting for study were enrolled, and sociodemographic and clinical details of patients were taken. Participants were randomized into two groups (short message service [SMS] vs. non-SMS group). At first intervention level, a SMS was sent to SMS group (not in non-SMS group) 1 day before their appointment. At second-level intervention (voice call level), patients from both groups who missed their first appointment were given a voice call requesting them to come for follow-up, and the reasons for first missed appointments (MA) were also elicited. The effect of these two intervention levels (first SMS for SMS group and next voice calls for both groups) on follow-up was evaluated. RESULTS: A total of 214 patients were enrolled in the study. At first SMS intervention level of SMS group (n = 106), 62.26% of participants reached appointment-on-time (RA), while in the non-SMS/as usual group (n = 108), 45.37% of patients RA. The difference of these groups is statistically significant. At second-level intervention (voice call), 66 of 88 (another 15 were unable to contact) were came for follow-up consultation within 2 days of MA. Distance and diagnosis of alcohol dependence were significantly associated with MA. Social reasons were most common reasons for first MA. CONCLUSION: The use of mobile phone technology in an outpatient community psychiatric clinic improved follow-up significantly.

12.
J Alzheimers Dis ; 56(1): 335-349, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28085018

RESUMO

It has been reported that cyclin-dependent kinase 5 (cdk5), a critical neuronal kinase, is hyperactivated in Alzheimer's disease (AD) and may be, in part, responsible for the hallmark pathology of amyloid plaques and neurofibrillary tangles (NFTs). It has been proposed by several laboratories that hyperactive cdk5 results from the overexpression of p25 (a truncated fragment of p35, the normal cdk5 regulator), which, when complexed to cdk5, induces hyperactivity, hyperphosphorylated tau/NFTs, amyloid-ß plaques, and neuronal death. It has previously been shown that intraperitoneal (i.p.) injections of a modified truncated 24-aa peptide (TFP5), derived from the cdk5 activator p35, penetrated the blood-brain barrier and significantly rescued AD-like pathology in 5XFAD model mice. The principal pathology in the 5XFAD mutant, however, is extensive amyloid plaques; hence, as a proof of concept, we believe it is essential to demonstrate the peptide's efficacy in a mouse model expressing high levels of p25, such as the inducible CK-p25Tg model mouse that overexpresses p25 in CamKII positive neurons. Using a modified TFP5 treatment, here we show that peptide i.p. injections in these mice decrease cdk5 hyperactivity, tau, neurofilament-M/H hyperphosphorylation, and restore synaptic function and behavior (i.e., spatial working memory, motor deficit using Rota-rod). It is noteworthy that TFP5 does not inhibit endogenous cdk5/p35 activity, nor other cdks in vivo suggesting it might have no toxic side effects, and may serve as an excellent therapeutic candidate for neurodegenerative disorders expressing abnormally high brain levels of p25 and hyperactive cdk5.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Potenciação de Longa Duração/efeitos dos fármacos , Peptídeos/farmacologia , Peptídeos/uso terapêutico , Fosfotransferases/metabolismo , Doença de Alzheimer/complicações , Doença de Alzheimer/genética , Animais , Antipsicóticos/farmacologia , Antipsicóticos/uso terapêutico , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/genética , Modelos Animais de Doenças , Doxiciclina/administração & dosagem , Agonistas de Aminoácidos Excitatórios/farmacologia , Comportamento Exploratório/efeitos dos fármacos , Comportamento Exploratório/fisiologia , Feminino , Hipocampo/efeitos dos fármacos , Hipocampo/fisiologia , Hipercinese/tratamento farmacológico , Hipercinese/etiologia , Potenciação de Longa Duração/genética , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Camundongos Transgênicos , Atividade Motora/efeitos dos fármacos , Atividade Motora/genética , N-Metilaspartato/farmacologia , Fosfotransferases/genética , Proteínas tau/metabolismo
13.
J Alzheimers Dis ; 54(2): 525-33, 2016 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-27567857

RESUMO

Cyclin-dependent kinase 5 (CDK5) is a multifunctional serine/threonine kinase that regulates a large number of neuronal processes essential for nervous system development and function with its activator p35 CDK5R1. Upon neuronal insults, p35 is proteolyzed and cleaved to p25 producing deregulation and hyperactivation of CDK5 (CDK5/p25), implicated in tau hyperphosphorylation, a pathology in some neurodegenerative diseases. A truncated, 24 amino acid peptide, p5, derived from p35 inhibits the deregulated CDK5 phosphotransferase activity and ameliorates Alzheimer's disease (AD) phenotypes in AD model mice. In the present study, we have screened a diverse panel of 70 human protein kinases for their sensitivities to p5, and a subset of these to p35. At least 16 of the tested protein kinases exhibited IC50 values that were 250 µM or less, with CAMK4, ZAP70, SGK1, and PIM1 showing greater sensitivity to inhibition by p5 than CDK5/p35 and CDK5/p25. In contrast, the p5 peptide modestly activated LKB1 and GSK3ß. A sub set of kinases screened against p35 showed that activity of CAMK4 in the absence of calcium and calmodulin was also markedly inhibited by p35. The Cyclin Y-dependent kinases PFTK1 (CDK14) and PCTK1 (CDK16) were activated by p35 at least 10-fold in the absence of Cyclin Y and by approximately 50% in its presence. These findings provide additional insights into the mechanisms of action for p5 and p35 in the regulation of protein phosphorylation in the nervous system.


Assuntos
Quinase 5 Dependente de Ciclina/metabolismo , Perfilação da Expressão Gênica/métodos , Proteínas do Tecido Nervoso/metabolismo , Fragmentos de Peptídeos/metabolismo , Sequência de Aminoácidos , Quinase 5 Dependente de Ciclina/genética , Humanos , Proteínas do Tecido Nervoso/genética , Fragmentos de Peptídeos/genética , Proteínas Quinases/genética , Proteínas Quinases/metabolismo
14.
Neural Regen Res ; 11(5): 698-701, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27335538

RESUMO

Cyclin-dependent kinase 5 (Cdk5) is a member of the serine-threonine kinase family of cyclin-dependent kinases. Cdk5 is critical to normal mammalian nervous system development and plays important regulatory roles in multiple cellular functions. Recent evidence indicates that Cdk5 is inappropriately activated in several neurodegenerative conditions, including Parkinson's disease (PD). PD is a chronic neurodegenerative disorder characterized by the loss of dopamine neurons in the substantia nigra, decreased striatal dopamine levels, and consequent extrapyramidal motor dysfunction. During neurotoxicity, p35 is cleaved to form p25. Binding of p25 with Cdk5 leads deregulation of Cdk5 resulting in number of neurodegenerative pathologies. To date, strategies to specifically inhibit Cdk5 hyperactivity have not been successful without affecting normal Cdk5 activity. Here we show that inhibition of p25/Cdk5 hyperactivation through TFP5/TP5, truncated 24-aa peptide derived from the Cdk5 activator p35 rescues nigrostriatal dopaminergic neurodegeneration induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP/MPP(+)) in a mouse model of PD. TP5 peptide treatment also blocked dopamine depletion in the striatum and improved gait dysfunction after MPTP administration. The neuroprotective effect of TFP5/TP5 peptide is also associated with marked reduction in neuroinflammation and apoptosis. Here we show inhibition of Cdk5/p25-hyperactivation by TFP5/TP5 peptide, which identifies Cdk5/p25 as a potential therapeutic target to reduce neurodegeneration in PD.

15.
J Alzheimers Dis ; 48(4): 1009-17, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26444778

RESUMO

Besides the hallmark pathology of amyloid plaques and neurofibrillary tangles, it is well documented that cyclin-dependent kinase 5 (CDK5), a critical neuronal protein kinase in nervous system development, function, and survival, when deregulated and hyperactivated induces Alzheimer's disease (AD) and amyotrophic lateral sclerosis and Parkinson's disease-like phenotypes in mice. In a recent study, we demonstrated that p5, a small, truncated fragment of 24 amino acid residues derived from the CDK5 activator protein 35 (NCK5A, p35), selectively inhibited deregulated CDK5 hyperactivity and ameliorated AD phenotypes in model mice. In this study, we identified the most inhibitory elements in the p5 peptide fragment. Each amino acid residue in p5 was systematically replaced with its homologous residues that may still be able to functionally substitute. The effects of these p5 peptide analogs were studied on the phosphotransferase activities of CDK5/p35, CDK5/p25, ERK1, and GSK3ß. The mimetic p5 peptide (A/V substitution at the C-terminus of the peptide) in the sequence, KNAFYERALSIINLMTSKMVQINV (p5-MT) was the most effective inhibitor of CDK5 kinase activity of 79 tested mimetic peptides including the original p5 peptide, KEAFWDRCLSVINLMSSKMLQINA (p5-WT). Replacement of the residues in C-terminus end of the peptide affected CDK5 phosphotransferase activity most significantly. These peptides were strong inhibitors of CDK5, but not the related proline-directed kinases, ERK1 and GSK3ß.


Assuntos
Quinase 5 Dependente de Ciclina/antagonistas & inibidores , Proteínas do Tecido Nervoso/metabolismo , Fragmentos de Peptídeos/metabolismo , Sequência de Aminoácidos , Animais , Quinase 5 Dependente de Ciclina/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Humanos , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Mimetismo Molecular , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Ensaio Radioligante , Proteínas Recombinantes/metabolismo , Células Sf9
16.
Mol Biol Cell ; 26(24): 4478-91, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26399293

RESUMO

Parkinson's disease (PD) is a chronic neurodegenerative disorder characterized by the loss of dopamine neurons in the substantia nigra, decreased striatal dopamine levels, and consequent extrapyramidal motor dysfunction. Recent evidence indicates that cyclin-dependent kinase 5 (Cdk5) is inappropriately activated in several neurodegenerative conditions, including PD. To date, strategies to specifically inhibit Cdk5 hyperactivity have not been successful without affecting normal Cdk5 activity. Previously we reported that TFP5 peptide has neuroprotective effects in animal models of Alzheimer's disease. Here we show that TFP5/TP5 selective inhibition of Cdk5/p25 hyperactivation in vivo and in vitro rescues nigrostriatal dopaminergic neurodegeneration induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP/MPP+) in a mouse model of PD. TP5 peptide treatment also blocked dopamine depletion in the striatum and improved gait dysfunction after MPTP administration. The neuroprotective effect of TFP5/TP5 peptide is also associated with marked reduction in neuroinflammation and apoptosis. Here we show selective inhibition of Cdk5/p25 -hyperactivation by TFP5/TP5 peptide, which identifies the kinase as a potential therapeutic target to reduce neurodegeneration in Parkinson's disease.


Assuntos
Fármacos Neuroprotetores/farmacologia , Doença de Parkinson/tratamento farmacológico , Fragmentos de Peptídeos/farmacologia , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Sequência de Aminoácidos , Animais , Quinase 5 Dependente de Ciclina/metabolismo , Modelos Animais de Doenças , Dopamina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/farmacologia , Neurônios/metabolismo , Doença de Parkinson/metabolismo , Substância Negra
17.
Kidney Int ; 88(1): 178-85, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25786102

RESUMO

India is experiencing an alarming rise in the burden of noncommunicable diseases, but data on the incidence of chronic kidney disease (CKD) are sparse. Using the Center for Cardiometabolic Risk Reduction in South Asia surveillance study (a population-based survey of Delhi and Chennai, India) we estimated overall, and age-, sex-, city-, and diabetes-specific prevalence of CKD, and defined the distribution of the study population by the Kidney Disease Improving Global Outcomes (KDIGO) classification scheme. The likelihood of cardiovascular events in participants with and without CKD was estimated by the Framingham and Interheart Modifiable Risk Scores. Of the 12,271 participants, 80% had complete data on serum creatinine and albuminuria. The prevalence of CKD and albuminuria, age standardized to the World Bank 2010 world population, was 8.7% (95% confidence interval: 7.9-9.4%) and 7.1% (6.4-7.7%), respectively. Nearly 80% of patients with CKD had an abnormally high hemoglobin A1c (5.7 and above). Based on KDIGO guidelines, 6.0, 1.0, and 0.5% of study participants are at moderate, high, or very high risk for experiencing CKD-associated adverse outcomes. The cardiovascular risk scores placed a greater proportion of patients with CKD in the high-risk categories for experiencing cardiovascular events when compared with participants without CKD. Thus, 1 in 12 individuals living in two of India's largest cities have evidence of CKD, with features that put them at high risk for adverse outcomes.


Assuntos
Diabetes Mellitus/epidemiologia , Insuficiência Renal Crônica/epidemiologia , População Urbana/estatística & dados numéricos , Adulto , Fatores Etários , Idoso , Albuminúria/epidemiologia , Doenças Cardiovasculares/epidemiologia , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Prevalência , Insuficiência Renal Crônica/complicações , Medição de Risco , Fatores Sexuais , Adulto Jovem
18.
J Alzheimers Dis ; 39(4): 899-909, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24326517

RESUMO

Multiple lines of evidence link the incidence of diabetes to the development of Alzheimer's disease (AD). Patients with diabetes have a 50 to 75% increased risk of developing AD. Cyclin dependent kinase 5 (Cdk5) is a serine/threonine protein kinase, which forms active complexes with p35 or p39, found principally in neurons and in pancreatic ß cells. Recent studies suggest that Cdk5 hyperactivity is a possible link between neuropathology seen in AD and diabetes. Previously, we identified P5, a truncated 24-aa peptide derived from the Cdk5 activator p35, later modified as TFP5, so as to penetrate the blood-brain barrier after intraperitoneal injections in AD model mice. This treatment inhibited abnormal Cdk5 hyperactivity and significantly rescued AD pathology in these mice. The present study explores the potential of TFP5 peptide to rescue high glucose (HG)-mediated toxicity in rat embryonic cortical neurons. HG exposure leads to Cdk5-p25 hyperactivity and oxidative stress marked by increased reactive oxygen species production, and decreased glutathione levels and superoxide dismutase activity. It also induces hyperphosphorylation of tau, neuroinflammation as evident from the increased expression of inflammatory cytokines like TNF-α, IL-1ß, and IL-6, and apoptosis. Pretreatment of cortical neurons with TFP5 before HG exposure inhibited Cdk5-p25 hyperactivity and significantly attenuated oxidative stress by decreasing reactive oxygen species levels, while increasing superoxide dismutase activity and glutathione. Tau hyperphosphorylation, inflammation, and apoptosis induced by HG were also considerably reduced by pretreatment with TFP5. These results suggest that TFP5 peptide may be a novel candidate for type 2 diabetes therapy.


Assuntos
Córtex Cerebral/metabolismo , Quinase 5 Dependente de Ciclina/química , Glucose/toxicidade , Neurônios/metabolismo , Fragmentos de Peptídeos/fisiologia , Fosfotransferases/fisiologia , Sequência de Aminoácidos , Animais , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/enzimologia , Quinase 5 Dependente de Ciclina/antagonistas & inibidores , Modelos Animais de Doenças , Dados de Sequência Molecular , Neurônios/enzimologia , Fosfotransferases/química , Ratos
19.
Histochem Cell Biol ; 140(1): 23-32, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23793952

RESUMO

The neuronal cytoskeleton is tightly regulated by phosphorylation and dephosphorylation reactions mediated by numerous associated kinases, phosphatases and their regulators. Defects in the relative kinase and phosphatase activities and/or deregulation of compartment-specific phosphorylation result in neurodegenerative disorders. The largest family of cytoskeletal proteins in mammalian cells is the superfamily of intermediate filaments (IFs). The neurofilament (NF) proteins are the major IFs. Aggregated forms of hyperphosphorylated tau and phosphorylated NFs are found in pathological cell body accumulations in the central nervous system of patients suffering from Alzheimer's disease, Parkinson's disease, and Amyotrophic Lateral Sclerosis. The precise mechanisms for this compartment-specific phosphorylation of cytoskeletal proteins are not completely understood. In this review, we focus on the mechanisms of neurofilament phosphorylation in normal physiology and neurodegenerative diseases. We also address the recent breakthroughs in our understanding the role of different kinases and phosphatases involved in regulating the phosphorylation status of the NFs. In addition, special emphasis has been given to describe the role of phosphatases and Pin1 in phosphorylation of NFs.


Assuntos
Filamentos Intermediários/enzimologia , Filamentos Intermediários/patologia , Neurônios/enzimologia , Peptidilprolil Isomerase/metabolismo , Humanos , Doenças Neurodegenerativas/enzimologia , Doenças Neurodegenerativas/fisiopatologia , Neurônios/patologia , Fosforilação
20.
Foot Ankle Spec ; 5(2): 102-6, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22343819

RESUMO

PURPOSE: The purpose of the study was to establish normative data on pressure distribution under the feet (plantar pressure) in standing using a free-mapping device and to find out the association of arch type to that of the plantar pressures. METHODS: A cross-sectional study was carried out among 628 participants aged between 6 and 81 years with no known foot problems or other ailments such as type 2 diabetes or neuropathy, which are known to have an impact on plantar pressures. Plantar pressure measurements were quantitatively recorded using a baropodometric platform (i-Step). RESULTS: In both males and females of the specified age-group, metatarsal heads were overloaded in terms of magnitude. Increased overload noted in the static plantar pressure measurement is associated with type of the foot arch and gender. A statistically significant relationship between the pressures of left and right feet, pressures under 2 different areas of foot (forefoot and heel), and the average pressures of both feet was also observed. CONCLUSION: These data could be used to establish age-based normative plantar pressures in the Indian population and provide a basis to assess feet with planus and cavus deformities.


Assuntos
Pé/fisiologia , Pressão , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...