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1.
Hum Mol Genet ; 31(11): 1788-1805, 2022 06 04.
Artículo en Inglés | MEDLINE | ID: mdl-34919689

RESUMEN

The purpose of our study is to understand the impact of a partial dynamin-related protein 1 (Drp1) on cognitive behavior, mitophagy, autophagy and mitochondrial and synaptic activities in transgenic Tau mice in Alzheimer's disease (AD). Our laboratory reported increased levels of amyloid-beta (Aß) and phosphorylated Tau (P-Tau) and reported that abnormal interactions between Aß and Drp1, P-Tau and Drp1 induced increased mitochondrial fragmentation and reduced fusion and synaptic activities in AD. These abnormal interactions result in the proliferation of dysfunctional mitochondria in AD neurons. Recent research on mitochondria revealed that fission protein Drp1 is largely implicated in mitochondrial dynamics in AD. To determine the impact of reduced Drp1 in AD, we recently crossed transgenic Tau mice with Drp1 heterozygote knockout (Drp1+/-) mice and generated double mutant (P301LDrp1+/-) mice. In the current study, we assessed the cognitive behavior, mRNA and protein levels of mitophagy, autophagy, mitochondrial biogenesis, dynamics and synaptic genes, mitochondrial morphology and mitochondrial function and dendritic spines in Tau mice relative to double mutant mice. When compared with Tau mice, double mutant mice did better on the Morris Maze (reduced latency to find hidden platform, increased swimming speed and time spent on quadrant) and rotarod (stayed a longer period of time) tests. Both mRNA- and protein-level autophagy, mitophagy, mitochondrial biogenesis and synaptic proteins were increased in double mutant mice compared with Tau (P301L) mice. Dendritic spines were significantly increased; mitochondrial number was reduced and length was increased in double mutant mice. Based on these observations, we conclude that reduced Drp1 is beneficial in a symptomatic-transgenic Tau (P301L) mice.


Asunto(s)
Enfermedad de Alzheimer , Dinaminas , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Animales , Autofagia/genética , Cognición , Espinas Dendríticas/metabolismo , Modelos Animales de Enfermedad , Dinaminas/genética , Dinaminas/metabolismo , Ratones , Ratones Transgénicos , Mitofagia/genética , ARN Mensajero
2.
Cell Mol Neurobiol ; 44(1): 6, 2023 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-38104307

RESUMEN

Multiple sclerosis (MS) is a chronic and degrading autoimmune disorder mainly targeting the central nervous system, leading to progressive neurodegeneration, demyelination, and axonal damage. Current treatment options for MS are limited in efficacy, generally linked to adverse side effects, and do not offer a cure. Stem cell therapies have emerged as a promising therapeutic strategy for MS, potentially promoting remyelination, exerting immunomodulatory effects and protecting against neurodegeneration. Therefore, this review article focussed on the potential of nano-engineering in stem cells as a therapeutic approach for MS, focusing on the synergistic effects of combining stem cell biology with nanotechnology to stimulate the proliferation of oligodendrocytes (OLs) from neural stem cells and OL precursor cells, by manipulating neural signalling pathways-PDGF, BMP, Wnt, Notch and their essential genes such as Sox, bHLH, Nkx. Here we discuss the pathophysiology of MS, the use of various types of stem cells in MS treatment and their mechanisms of action. In the context of nanotechnology, we present an overview of its applications in the medical and research field and discuss different methods and materials used to nano-engineer stem cells, including surface modification, biomaterials and scaffolds, and nanoparticle-based delivery systems. We further elaborate on nano-engineered stem cell techniques, such as nano script, nano-exosome hybrid, nano-topography and their potentials in MS. The article also highlights enhanced homing, engraftment, and survival of nano-engineered stem cells, targeted and controlled release of therapeutic agents, and immunomodulatory and tissue repair effects with their challenges and limitations. This visual illustration depicts the process of utilizing nano-engineering in stem cells and exosomes for the purpose of delivering more accurate and improved treatments for Multiple Sclerosis (MS). This approach targets specifically the creation of oligodendrocytes, the breakdown of which is the primary pathological factor in MS.


Asunto(s)
Esclerosis Múltiple , Células-Madre Neurales , Humanos , Esclerosis Múltiple/patología , Oligodendroglía/metabolismo , Sistema Nervioso Central/patología , Axones/patología , Vaina de Mielina/patología
3.
Qatar Med J ; 2023(4): 32, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38187992

RESUMEN

BACKGROUND: Febrile seizures, convulsive episodes in young children during febrile illnesses, are a significant concern due to their potential for recurrence and associated uncertainties. This study investigated the causes and risks associated with recurrent febrile seizures and the critical role of electroencephalogram (EEG) in their accurate diagnosis. METHODS: Following Institutional Review Board approval and going through the consenting process with parents, this study gathered the clinical features and EEG recordings of children admitted with febrile seizures in the Department of Pediatrics, Mahatma Gandhi Memorial Hospital, Kakatiya Medical College, Warangal, Telangana, India. Descriptive statistics, including mean, standard deviation (SD), frequencies, and percentages, were computed to understand the data comprehensively. The Chi-Square test was employed to analyze the association between variables, with a significance level of 0.05, ensuring reliable and trustworthy findings. RESULTS: Out of 42 children studied, 28 (66.67%) presented with simple febrile seizures, with the mean time of occurrence of seizures from the onset of fever being 7.85 hours. Abnormal EEG was seen in 50% of children with complex febrile seizures and 16% with simple febrile seizures. Generalized epileptiform discharges were the most common epileptic activity observed. Low sodium levels had a significant relationship with febrile seizures in the analysis. CONCLUSIONS: This study emphasizes the importance of EEG in diagnosing febrile seizures, particularly in complex cases. Our findings suggest that low sodium levels may be a significant risk factor for febrile seizures. Further research is necessary to identify other preventable risk factors to reduce the burden of the medical condition.

4.
Hum Mol Genet ; 28(2): 177-199, 2019 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-30239719

RESUMEN

The purpose of our study was to better understand the effects of mitochondrial-division inhibitor 1 (Mdivi-1) on mitochondrial fission, mitochondrial biogenesis, electron transport activities and cellular protection. In recent years, researchers have found excessive mitochondrial fragmentation and reduced fusion in a large number of diseases with mitochondrial dysfunction. Therefore, several groups have developed mitochondrial division inhibitors. Among these, Mdivi-1 was extensively studied and was found to reduce dynamin-related protein 1 (Drp1) levels and excessive mitochondrial fission, enhance mitochondrial fusion activity and protect cells. However, a recent study by Bordt et al. (1) questioned earlier findings of the beneficial, inhibiting effects of Mdivi-1. In the current study, we studied the protective effects of Mdivi-1 by studying the following: mRNA and protein levels of electron transport chain (ETC) genes; mitochondrial dynamics and biogenesis genes; enzymatic activities of ETC complexes I, II, III and IV; the mitochondrial network; mitochondrial size & number; Drp1 GTPase enzymatic activity and mitochondrial respiration (1) in N2a cells treated with Mdivi-1, (2) overexpressed with full-length Drp1 + Mdivi-1-treated N2a cells and (3) Drp1 RNA silenced+Mdivi-1-treated N2a cells. We found reduced levels of the fission genes Drp1 and Fis1 levels; increased levels of the fusion genes Mfn1, Mfn2 and Opa1; and the biogenesis genes PGC1α, nuclear respiration factor 1, nuclear respiratory factor 2 and transcription factor A, mitochondrial. Increased levels mRNA and protein levels were found in ETC genes of complexes I, II and IV genes. Immunoblotting data agreed with mRNA changes. Transmission electron microscopy analysis revealed reduced numbers of mitochondria and increased length of mitochondria (1) in N2a cells treated with Mdivi-1, (2) cells overexpressed with full-length Drp1 + Mdivi-1-treated N2a cells and (3) Drp1 RNA silenced+Mdivi-1-treated N2a cells. Immunofluorescence analysis revealed that mitochondrial network was increased. Increased levels of complex I, II and IV enzymatic activities were found in all three groups of cells treated with low concentration of Mdivi-1. Mitochondrial function was increased and GTPase Drp1 activity was decreased in all three groups of N2a cells. These observations strongly suggest that Mdivi-1 is a Drp1 inhibitor and directly reduces mitochondrial fragmentation and further, Mdivi-1 is a promising molecule to treat human diseases with ETC complexes, I, II and IV.


Asunto(s)
GTP Fosfohidrolasas/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Mitocondrias/efectos de los fármacos , Dinámicas Mitocondriales/efectos de los fármacos , Proteínas Mitocondriales/metabolismo , Quinazolinonas/farmacología , Animales , Línea Celular Tumoral , Dinaminas , Transporte de Electrón/efectos de los fármacos , Transporte de Electrón/genética , Humanos , Immunoblotting , Ratones , Mitocondrias/metabolismo , Dinámicas Mitocondriales/genética , Biogénesis de Organelos , Fosforilación , Interferencia de ARN , ARN Mensajero/metabolismo , Transfección
5.
J Neurosci Res ; 99(4): 1120-1135, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33465841

RESUMEN

Alzheimer's disease (AD) is the most common type of dementia and progressive neurodegenerative disease. The presence of ß-amyloid (Aß) plaques and phosphorylated Tau tangles are considered to be the two main hallmarks of AD. Recent findings have shown that different changes in the structure and dynamics of mitochondria play an important role in AD pathology progression. Mitochondrial changes in AD are expressed as enhanced mitochondrial fragmentation, altered mitochondrial dynamics, and changes in the expression of mitochondrial biogenesis genes in vitro and in vivo models. Therefore, targeting mitochondria and associated mitochondrial proteins seems to be a promising alternative instead of targeting Aß and Tau in the prevention of Alzheimer's disease. The dynamin-related protein (Drp1) is one such protein that plays an important role in the regulation of mitochondrial division and maintenance of mitochondrial structures. Few researchers have shown that inhibition of Drp1 GTPase activity in neuronal cells rescues excessive mitochondrial fragmentation. In addition, the growing evidence revealed that Drp1 can interact with both Aß and Tau protein in human brain tissues and mouse models. In this review, we would like to update existing knowledge about various changes in and around mitochondria related to the pathogenesis of Alzheimer's disease, with particular emphasis on mitophagy and autophagy.


Asunto(s)
Enfermedad de Alzheimer/patología , Dinaminas/metabolismo , Mitocondrias/patología , Mitofagia/fisiología , Péptidos beta-Amiloides/metabolismo , Animales , Autofagia , Encéfalo/metabolismo , Encéfalo/fisiopatología , Humanos , Mitocondrias/metabolismo , Proteínas Mitocondriales/metabolismo , Enfermedades Neurodegenerativas/patología , Proteínas Quinasas/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Proteínas tau/metabolismo
6.
Int J Mol Sci ; 22(19)2021 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-34638664

RESUMEN

Multiple sclerosis (MS) is a complex disease of the central nervous system (CNS) that involves an intricate and aberrant interaction of immune cells leading to inflammation, demyelination, and neurodegeneration. Due to the heterogeneity of clinical subtypes, their diagnosis becomes challenging and the best treatment cannot be easily provided to patients. Biomarkers have been used to simplify the diagnosis and prognosis of MS, as well as to evaluate the results of clinical treatments. In recent years, research on biomarkers has advanced rapidly due to their ability to be easily and promptly measured, their specificity, and their reproducibility. Biomarkers are classified into several categories depending on whether they address personal or predictive susceptibility, diagnosis, prognosis, disease activity, or response to treatment in different clinical courses of MS. The identified members indicate a variety of pathological processes of MS, such as neuroaxonal damage, gliosis, demyelination, progression of disability, and remyelination, among others. The present review analyzes biomarkers in cerebrospinal fluid (CSF) and blood serum, the most promising imaging biomarkers used in clinical practice. Furthermore, it aims to shed light on the criteria and challenges that a biomarker must face to be considered as a standard in daily clinical practice.


Asunto(s)
Biomarcadores/sangre , Biomarcadores/líquido cefalorraquídeo , Esclerosis Múltiple/patología , Progresión de la Enfermedad , Humanos , Inflamación/sangre , Inflamación/líquido cefalorraquídeo , Inflamación/patología , Esclerosis Múltiple/sangre , Esclerosis Múltiple/líquido cefalorraquídeo , Pronóstico , Reproducibilidad de los Resultados
7.
Hum Mol Genet ; 27(8): 1332-1342, 2018 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-29408999

RESUMEN

The purpose of our study was to determine the toxic effects of hippocampal mutant APP and amyloid beta (Aß) in 12-month-old APP transgenic mice. Using rotarod and Morris water maze tests, immunoblotting and immunofluorescence, Golgi-cox staining and transmission electron microscopy, we assessed cognitive behavior, protein levels of synaptic, autophagy, mitophagy, mitochondrial dynamics, biogenesis, dendritic protein MAP2 and quantified dendritic spines and mitochondrial number and length in 12-month-old APP mice that express Swedish mutation. Mitochondrial function was assessed by measuring the levels of hydrogen peroxide, lipid peroxidation, cytochrome c oxidase activity and mitochondrial ATP. Morris water maze and rotarod tests revealed that hippocampal learning and memory and motor learning and coordination were impaired in APP mice relative to wild-type (WT) mice. Increased levels of mitochondrial fission proteins, Drp1 and Fis1 and decreased levels of fusion (Mfn1, Mfn2 and Opa1) biogenesis (PGC1α, NRF1, NRF2 and TFAM), autophagy (ATG5 and LC3BI, LC3BII), mitophagy (PINK1 and TERT), synaptic (synaptophysin and PSD95) and dendritic (MAP2) proteins were found in 12-month-old APP mice relative to age-matched non-transgenic WT mice. Golgi-cox staining analysis revealed that dendritic spines are significantly reduced. Transmission electron microscopy revealed significantly increased mitochondrial numbers and reduced mitochondrial length in APP mice. These findings suggest that hippocampal accumulation of mutant APP and Aß is responsible for abnormal mitochondrial dynamics and defective biogenesis, reduced MAP2, autophagy, mitophagy and synaptic proteins and reduced dendritic spines and hippocampal-based learning and memory impairments, and mitochondrial structural and functional changes in 12-month-old APP mice.


Asunto(s)
Enfermedad de Alzheimer/genética , Péptidos beta-Amiloides/genética , Precursor de Proteína beta-Amiloide/genética , Hipocampo/metabolismo , Mitocondrias/metabolismo , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/fisiopatología , Péptidos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Autofagia , Proteína 5 Relacionada con la Autofagia/genética , Proteína 5 Relacionada con la Autofagia/metabolismo , Modelos Animales de Enfermedad , Dinaminas/genética , Dinaminas/metabolismo , Femenino , GTP Fosfohidrolasas/genética , GTP Fosfohidrolasas/metabolismo , Regulación de la Expresión Génica , Hipocampo/fisiopatología , Humanos , Masculino , Aprendizaje por Laberinto , Memoria/fisiología , Ratones , Ratones Transgénicos , Proteínas Asociadas a Microtúbulos/genética , Proteínas Asociadas a Microtúbulos/metabolismo , Mitocondrias/patología , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Mitofagia , Neuronas/metabolismo , Neuronas/patología , Neuronas/ultraestructura , Prueba de Desempeño de Rotación con Aceleración Constante , Lóbulo Temporal/metabolismo , Lóbulo Temporal/fisiopatología
8.
Hum Mol Genet ; 27(1): 30-40, 2018 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-29040533

RESUMEN

The purpose of our study was to understand the toxic effects of hippocampal phosphorylated tau in tau mice. Using rotarod and Morris water maze (MWM) tests, immunoblotting and immunofluorescence, Golgi-Cox staining and transmission electron microscopy, we assessed cognitive behavior, measured protein levels of mitochondrial dynamics, MAP2, total and phosphorylated tau, and quantified dendritic spines and mitochondrial number and length in 12-month-old tau mice with P301L mutation. Mitochondrial function was assessed by measuring the levels of H2O2, lipid peroxidation, cytochrome oxidase activity and mitochondrial ATP. MWM and rotarod tests revealed that hippocampal learning and memory and motor learning and coordination were impaired in tau mice relative to wild-type (WT) mice. Increased levels of mitochondrial fission proteins, Drp1 and Fis1 and decreased levels of mitochondrial fusion proteins, Mfn1, Mfn2 and Opa1 were found in 12-month-old tau mice relative to age-matched WT mice, indicating that the presence of abnormal mitochondrial dynamics in tau mice. Decreased levels of dendritic protein, MAP2 and increased levels of total and phosphorylated tau proteins were found in tau mice relative to WT mice. Mitochondrial function was defective. Golgi-Cox staining analysis revealed that dendritic spines are significantly reduced. Transmission electron microscopy revealed significantly increased mitochondrial numbers and reduced mitochondrial length in tau mice. These findings suggest that hippocampal accumulation of phosphorylated tau is responsible for abnormal mitochondrial dynamics and reducing dendritic protein MAP2 and dendritic spines and hippocampal based learning and memory impairments, and mitochondrial structural and functional changes in tau mice. Based on these observations, we propose that reduced hippocampal phosphorylated tau is an important therapeutic strategy for AD and other tauopathies.


Asunto(s)
Enfermedad de Alzheimer/fisiopatología , Proteínas tau/metabolismo , Péptidos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Cognición/fisiología , Disfunción Cognitiva/metabolismo , Espinas Dendríticas/metabolismo , Espinas Dendríticas/fisiología , Modelos Animales de Enfermedad , Hipocampo/metabolismo , Hipocampo/fisiología , Ratones , Ratones Transgénicos , Mitocondrias/metabolismo , Mitocondrias/fisiología , Dinámicas Mitocondriales , Proteínas Mitocondriales/genética , Neuronas/metabolismo , Fosforilación , Sinapsis/metabolismo , Tauopatías/metabolismo
9.
Molecules ; 25(24)2020 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-33322198

RESUMEN

Angiotensin-converting enzyme 2 (ACE2) is the cellular receptor for the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that is engendering the severe coronavirus disease 2019 (COVID-19) pandemic. The spike (S) protein receptor-binding domain (RBD) of SARS-CoV-2 binds to the three sub-domains viz. amino acids (aa) 22-42, aa 79-84, and aa 330-393 of ACE2 on human cells to initiate entry. It was reported earlier that the receptor utilization capacity of ACE2 proteins from different species, such as cats, chimpanzees, dogs, and cattle, are different. A comprehensive analysis of ACE2 receptors of nineteen species was carried out in this study, and the findings propose a possible SARS-CoV-2 transmission flow across these nineteen species.


Asunto(s)
Enzima Convertidora de Angiotensina 2 , COVID-19 , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Enzima Convertidora de Angiotensina 2/genética , Enzima Convertidora de Angiotensina 2/metabolismo , Animales , COVID-19/genética , COVID-19/metabolismo , COVID-19/transmisión , Gatos , Bovinos , Perros , Humanos , Pan troglodytes , Dominios Proteicos , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , Especificidad de la Especie , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/metabolismo
10.
Hum Mol Genet ; 26(8): 1483-1496, 2017 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-28186562

RESUMEN

The objective of our study was to better understand the protective effects of the mitochondria-targeted tetra-peptide SS31 against amyloid beta (Aß)-induced mitochondrial and synaptic toxicities in Alzheimer's disease (AD) progression. Using intraperitoneal injections, we administered SS31 to an AD mouse model (APP) over a period of 6 weeks, beginning when the APP mice were 12 months of age. We studied their cortical tissues after SS31 treatment and determined that SS31 crosses the blood brain barrier and reaches mitochondrial sites of free radical production. We also determined: (1) plasma and brain levels of SS31, (2) mRNA levels and levels of mitochondrial dynamics, biogenesis proteins and synaptic proteins, (3) soluble Aß levels and immunoreactivity of mutant APP and Aß levels and (4) mitochondrial function by measuring H2O2, lipid peroxidation, cytochrome c oxidase activity and mitochondrial ATP. We found reduced mRNA expression and reduced protein levels of fission genes, and increased levels of mitochondrial fusion, biogenesis and synaptic genes in SS31-treated APP mice relative to SS31-untreated APP mice. Immunofluorescence analysis revealed reduced full-length mutant APP and soluble/insoluble Aß levels in the SS31-treated APP mice. Sandwich ELISA assays revealed significantly reduced soluble Aß levels in the SS31-treated APP mice relative to the untreated APP mice. Mitochondrial function was maintained in the SS31-treated APP mice over the 6 weeks of SS31 treatment compared with mitochondrial function in the untreated APP mice. Our findings indicate that SS31 treatment reduces Aß production, reduces mitochondrial dysfunction, maintains mitochondrial dynamics and enhances mitochondrial biogenesis and synaptic activity in APP mice; and that SS31 may confer protective effects against mitochondrial and synaptic toxicities in APP transgenic mice.


Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Péptidos beta-Amiloides/metabolismo , Mitocondrias/efectos de los fármacos , Oligopéptidos/administración & dosificación , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Animales , Encéfalo/efectos de los fármacos , Encéfalo/patología , Modelos Animales de Enfermedad , Humanos , Peroxidación de Lípido/efectos de los fármacos , Ratones , Ratones Transgénicos , Mitocondrias/patología , Neuronas/efectos de los fármacos , Neuronas/patología , Oligopéptidos/metabolismo
11.
Hum Mol Genet ; 25(23): 5148-5166, 2016 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-27677309

RESUMEN

The purpose of our study was to understand the protective effects of reduced expression of dynamin-related protein (Drp1) against amyloid beta (Aß) induced mitochondrial and synaptic toxicities in Alzheimer's disease (AD) progression and pathogenesis. Our recent molecular and biochemical studies revealed that impaired mitochondrial dynamics-increased mitochondrial fragmentation and decreased fusion-in neurons from autopsy brains of AD patients and from transgenic AD mice and neurons expressing Aß, suggesting that Aß causes mitochondrial fragmentation in AD. Further, our recent co-immunoprecipitation and immunostaining analysis revealed that the mitochondrial fission protein Drp1 interacted with Aß, and this interaction increased as AD progressed. Based on these findings, we hypothesize that a partial deficiency of Drp1 inhibits Drp1-Aß interactions and protects Aß-induced mitochondrial and synaptic toxicities, and maintains mitochondrial dynamics and neuronal function in AD neurons. We crossed Drp1+/- mice with APP transgenic mice (Tg2576 line) and created double mutant (APPXDrp1+/-) mice. Using real-time RT-PCR and immunoblotting analyses, we measured mRNA expressions and protein levels of genes related to the mitochondrial dynamics, mitochondrial biogenesis and synapses from 6-month-old Drp1+/-, APP, APPXDrp1+/- and wild-type (WT) mice. Using biochemical methods, we also studied mitochondrial function and measured soluble Aß in brain tissues from all lines of mice in our study. Decreased mRNA expressions and protein levels of Drp1 and Fis1 (fission) and CypD (matrix) genes, and increased levels of Mfn1, Mfn2 and Opa1 (fusion), Nrf1, Nrf2, PGC1α, TFAM (biogenesis) and synaptophysin, PSD95, synapsin 1, synaptobrevin 1, neurogranin, GAP43 and synaptopodin (synaptic) were found in 6-month-old APPXDrp1+/- mice relative to APP mice. Mitochondrial functional assays revealed that mitochondrial dysfunction is reduced in APPXDrp1+/- mice relative to APP mice, suggesting that reduced Drp1enhances mitochondrial function in AD neurons. Sandwich ELISA assay revealed that soluble Aß levels were significantly reduced in APPXDrp1+/- mice relative to APP mice, indicating that reduced Drp1 decreases soluble Aß production in AD progression. These findings suggest that a partial reduction of Drp1 reduces Aß production, reduces mitochondrial dysfunction, and maintains mitochondrial dynamics, enhances mitochondrial biogenesis and synaptic activity in APP mice. These findings may have implications for the development of Drp1 based therapeutics for AD patients.


Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Péptidos beta-Amiloides/genética , Dinaminas/genética , Mitocondrias/genética , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/metabolismo , Animales , Encéfalo/metabolismo , Encéfalo/patología , Modelos Animales de Enfermedad , Dinaminas/antagonistas & inhibidores , Humanos , Ratones , Ratones Transgénicos , Mitocondrias/patología , Dinámicas Mitocondriales/efectos de los fármacos , Terapia Molecular Dirigida , Neuronas/metabolismo , Neuronas/patología , Sinapsis/efectos de los fármacos , Sinapsis/patología
12.
Hum Mol Genet ; 25(22): 4881-4897, 2016 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-28173111

RESUMEN

The purpose of our study was to understand the protective effects of a partial reduction of dynamin-related protein 1 (Drp1) in Alzheimer's disease (AD) progression and pathogenesis. Increasing evidence suggests that phosphorylated Tau and mitochondrial abnormalities are involved in the loss of synapses, defective axonal transport and cognitive decline, in patients with AD. In the current study, we investigated whether a partial reduction of Drp1 protect neurons from phosphorylated Tau-induced mitochondrial and synaptic toxicities in AD progression. We crossed Drp1+/− mice with Tau transgenic mice (P301L line) and created double mutant (TauXDrp1+/−) mice. Using real-time RT-PCR, immunoblotting and immunostaining analyses, we measured mRNA expressions and protein levels of genes related to the mitochondrial dynamics­Drp1 and Fis1 (fission), Mfn1, Mfn2 and Opa1 (fusion), CypD (matrix), mitochondrial biogenesis­Nrf1, Nrf2, PGC1α and TFAM and synaptic­synaptophysin, PSD95, synapsin 1, synaptobrevin 1, neurogranin, GAP43 and synaptopodin in brain tissues from 6-month-old Drp1+/−, Tau, TauXDrp1+/− and wild-type mice. Using biochemical and immunoblotting methods, mitochondrial function and phosphorylated Tau were measured. Decreased mRNA and protein levels of fission and matrix and increased levels of fusion, mitochondrial biogenesis, and synaptic genes were found in 6-month-old TauXDrp1+/− mice relative to Tau mice. Mitochondrial dysfunction was reduced in TauXDrp1+/− mice relative to Tau mice. Phosphorylated Tau found to be reduced in TauXDrp1+/− mice relative to Tau mice. These findings suggest that a partial reduction of Drp1 decreases the production of phosphorylated Tau, reduces mitochondrial dysfunction, and maintains mitochondrial dynamics, enhances mitochondrial biogenesis and synaptic activity in Tau mice. Findings of this study may have implications for the development of Drp1 based therapeutics for patients with AD and other tauopathies.


Asunto(s)
Enfermedad de Alzheimer/patología , Dinaminas/metabolismo , Dinámicas Mitocondriales/fisiología , Sinapsis/patología , Proteínas tau/metabolismo , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Modelos Animales de Enfermedad , Dinaminas/genética , Humanos , Ratones , Ratones Noqueados , Ratones Transgénicos , Mitocondrias/metabolismo , Neuronas/metabolismo , Fosforilación , Proteolisis , Sinapsis/metabolismo , Proteínas tau/genética
13.
Alzheimers Dement ; 14(7): 913-924, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29601787

RESUMEN

INTRODUCTION: Apolipoprotein E (APOE) ε4 is the major genetic risk factor for Alzheimer's disease (AD), but its prevalence is unclear because earlier studies did not require biomarker evidence of amyloid ß (Aß) pathology. METHODS: We included 3451 Aß+ subjects (853 AD-type dementia, 1810 mild cognitive impairment, and 788 cognitively normal). Generalized estimating equation models were used to assess APOE ε4 prevalence in relation to age, sex, education, and geographical location. RESULTS: The APOE ε4 prevalence was 66% in AD-type dementia, 64% in mild cognitive impairment, and 51% in cognitively normal, and it decreased with advancing age in Aß+ cognitively normal and Aß+ mild cognitive impairment (P < .05) but not in Aß+ AD dementia (P = .66). The prevalence was highest in Northern Europe but did not vary by sex or education. DISCUSSION: The APOE ε4 prevalence in AD was higher than that in previous studies, which did not require presence of Aß pathology. Furthermore, our results highlight disease heterogeneity related to age and geographical location.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Apolipoproteína E4/genética , Disfunción Cognitiva/metabolismo , Anciano , Alelos , Biomarcadores/líquido cefalorraquídeo , Europa (Continente) , Femenino , Humanos , Masculino , Tomografía de Emisión de Positrones , Prevalencia
14.
Biochim Biophys Acta ; 1862(4): 814-828, 2016 04.
Artículo en Inglés | MEDLINE | ID: mdl-26708942

RESUMEN

Mitochondria play a large role in neuronal function by constantly providing energy, particularly at synapses. Recent studies suggest that amyloid beta (Aß) and phosphorylated tau interact with the mitochondrial fission protein, dynamin-related protein 1 (Drp1), causing excessive fragmentation of mitochondria and leading to abnormal mitochondrial dynamics and synaptic degeneration in Alzheimer's disease (AD) neurons. Recent research also revealed Aß-induced and phosphorylated tau-induced changes in mitochondria, particularly affecting mitochondrial shape, size, distribution and axonal transport in AD neurons. These changes affect mitochondrial health and, in turn, could affect synaptic function and neuronal damage and ultimately leading to memory loss and cognitive impairment in patients with AD. This article highlights recent findings in the role of Drp1 in AD pathogenesis. This article also highlights Drp1 and its relationships to glycogen synthase kinase 3, cyclin-dependent kinase 5, p53, and microRNAs in AD pathogenesis.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Axones/metabolismo , GTP Fosfohidrolasas/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Mitocondrias/metabolismo , Proteínas Mitocondriales/metabolismo , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/genética , Péptidos beta-Amiloides/metabolismo , Animales , Axones/patología , Quinasa 5 Dependiente de la Ciclina/genética , Quinasa 5 Dependiente de la Ciclina/metabolismo , Dinaminas , GTP Fosfohidrolasas/genética , Glucógeno Sintasa Quinasa 3/genética , Glucógeno Sintasa Quinasa 3/metabolismo , Humanos , MicroARNs/genética , MicroARNs/metabolismo , Proteínas Asociadas a Microtúbulos/genética , Mitocondrias/patología , Proteínas Mitocondriales/genética , Transporte de Proteínas/genética , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo
15.
Biochem Biophys Res Commun ; 483(4): 1156-1165, 2017 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-27524239

RESUMEN

Currently, 5.4 million Americans suffer from AD, and these numbers are expected to increase up to 16 million by 2050. Despite tremendous research efforts, we still do not have drugs or agents that can delay, or prevent AD and its progression, and we still do not have early detectable biomarkers for AD. Multiple cellular changes have been implicated in AD, including synaptic damage, mitochondrial damage, production and accumulation of Aß and phosphorylated tau, inflammatory response, deficits in neurotransmitters, deregulation of the cell cycle, and hormonal imbalance. Research into AD has revealed that miRNAs are involved in each of these cellular changes and interfere with gene regulation and translation. Recent discoveries in molecular biology have also revealed that microRNAs play a major role in post-translational regulation of gene expression. The purpose of this article is to review research that has assessed neuroprotective and neurodegenerative characteristics of microRNAs in brain samples from AD transgenic mouse models and patients with AD.


Asunto(s)
MicroARNs/genética , Enfermedades Neurodegenerativas/genética , Neuroprotección/genética , Envejecimiento/genética , Animales , Biomarcadores/sangre , Senescencia Celular/genética , Humanos , Ratones , Ratones Transgénicos
16.
Biochim Biophys Acta Mol Basis Dis ; 1863(5): 1026-1036, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28130199

RESUMEN

The purpose of this review article is to understand the current literature on obesity, diabetes and therapeutic avenues across the world. Diabetes is a chronic lifestyle condition that affects millions of people worldwide and it is a major health concern in our society. Diabetes and obesity are associated with various conditions, including non-modifiable and modifiable risk factors. Early detectable markers are not well established to detect pre-diabetes and as a result, it becomes diabetes. Several published epidemiological studies were assessed and the findings were summarized. Resources from published studies were used to identify criteria used for pre-diabetes, the role of diet in pre-diabetics and potential risks and characteristics associated with pre-diabetes. Preventive strategies are needed to combat diabetes. Individuals diagnosed with pre-diabetes need detailed education, need to fully understand the risk factors and have the ability to manage diabetes. Interventions exist that include chronic disease self-management programs, lifestyle interventions and pharmacological strategies. Obesity plays a large role in causing pre-diabetes and diabetes. Critical analysis of existing epidemiological research data suggests that additional research is needed to determine the efficacy of interventions. This article is part of a Special Issue entitled: Oxidative Stress and Mitochondrial Quality in Diabetes/Obesity and Critical Illness Spectrum of Diseases - edited by P. Hemachandra Reddy.


Asunto(s)
Diabetes Mellitus/epidemiología , Obesidad/complicaciones , Animales , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/genética , Diabetes Mellitus/terapia , Dietoterapia , Terapia por Ejercicio , Humanos , Insulina/genética , Estilo de Vida , Obesidad/terapia , Factores de Riesgo
17.
Biochim Biophys Acta Mol Basis Dis ; 1863(5): 1078-1089, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-27567931

RESUMEN

Recently researchers proposed the term 'Type-3-Diabetes' for Alzheimer's disease (ad) because of the shared molecular and cellular features among Type-1-Diabetes, Type-2-Diabetes and insulin resistance associated with memory deficits and cognitive decline in elderly individuals. Recent clinical and basic studies on patients with diabetes and AD revealed previously unreported cellular and pathological among diabetes, insulin resistance and AD. These studies are also strengthened by various basic biological studies that decipher the effects of insulin in the pathology of AD through cellular and molecular mechanisms. For instance, insulin is involved in the activation of glycogen synthase kinase 3ß, which in turn causes phosphorylation of tau, which involved in the formation of neurofibrillary tangles. Interestingly, insulin also plays a crucial role in the formation amyloid plaques. In this review, we discussed significant shared mechanisms between AD and diabetes and we also provided therapeutic avenues for diabetes and AD. This article is part of a Special Issue entitled: Oxidative Stress and Mitochondrial Quality in Diabetes/Obesity and Critical Illness Spectrum of Diseases - edited by P. Hemachandra Reddy.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Amiloide/metabolismo , Diabetes Mellitus/metabolismo , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Insulina/metabolismo , Proteínas tau/metabolismo , Enfermedad de Alzheimer/clasificación , Enfermedad de Alzheimer/patología , Animales , Diabetes Mellitus/clasificación , Diabetes Mellitus/patología , Humanos , Fosforilación
18.
Biochim Biophys Acta Mol Basis Dis ; 1863(7): 1858-1866, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-27262357

RESUMEN

In the previous study, we demonstrated that dichlorvos induces oxidative stress in dopaminergic neuronal cells and subsequent caspase activation mediates apoptosis. In the present study, we evaluated the effect and mechanism of dichlorvos induced oxidative stress on cell cycle activation in NGF-differentiated PC12 cells. Dichlorvos exposure resulted in oxidative DNA damage along with activation of cell cycle machinery in differentiated PC12 cells. Dichlorvos exposed cells exhibited an increased expression of p53, cyclin-D1, pRb and decreased expression of p21suggesting a re-entry of differentiated cells into the cell cycle. Cell cycle analysis of dichlorvos exposed cells revealed a reduction of cells in the G0/G1 phase of the cell cycle (25%), and a concomitant increase of cells in S phase (30%) and G2/M phase (43.3%) compared to control PC12 cells. Further, immunoblotting of cytochrome c, Bax, Bcl-2 and cleaved caspase-3 revealed that dichlorvos induces a caspase-dependent cell death in PC12 cells. These results suggest that Dichlorvos exposure has the potential to generate oxidative stress which evokes activation of cell cycle machinery leading to apoptotic cell death via cytochrome c release from mitochondria and subsequent caspase-3 activation in differentiated PC12 cells.


Asunto(s)
Ciclo Celular/efectos de los fármacos , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Diclorvos/efectos adversos , Neuronas Dopaminérgicas/metabolismo , Enfermedades Neurodegenerativas/metabolismo , Intoxicación por Organofosfatos/metabolismo , Animales , Apoptosis/efectos de los fármacos , Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/metabolismo , Ciclo Celular/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Diclorvos/farmacología , Neuronas Dopaminérgicas/patología , Enfermedades Neurodegenerativas/inducido químicamente , Enfermedades Neurodegenerativas/genética , Enfermedades Neurodegenerativas/patología , Intoxicación por Organofosfatos/genética , Intoxicación por Organofosfatos/patología , Estrés Oxidativo/efectos de los fármacos , Células PC12 , Ratas
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