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1.
Mol Neurobiol ; 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38558361

RESUMO

Alzheimer's disease (AD) is a distressing neurodegenerative condition characterized by the accumulation of amyloid-beta (Aß) plaques and tau tangles within the brain. The interconnectedness between membrane transporters (SLCs) and microRNAs (miRNAs) in AD pathogenesis has gained increasing attention. This review explores the localization, substrates, and functions of SLC transporters in the brain, emphasizing the roles of transporters for glutamate, glucose, nucleosides, and other essential compounds. The examination delves into the significance of SLCs in AD, their potential for drug development, and the intricate realm of miRNAs, encompassing their transcription, processing, functions, and regulation. MiRNAs have emerged as significant players in AD, including those associated with mitochondria and synapses. Furthermore, this review discusses the intriguing nexus of miRNAs targeting SLC transporters and their potential as therapeutic targets in AD. Finally, the review underscores the interaction between SLC transporters and miRNA regulation within the context of Alzheimer's disease, underscoring the need for further research in this area. This comprehensive review aims to shed light on the complex mechanisms underlying the causation of AD and provides insights into potential therapeutic approaches.

2.
J Alzheimers Dis ; 98(4): 1329-1348, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38552115

RESUMO

Background: The intricate and complex molecular mechanisms that underlie the progression of Alzheimer's disease (AD) have prompted a concerted and vigorous research endeavor aimed at uncovering potential avenues for therapeutic intervention. Objective: This study aims to elucidate the role of miRNA PC-5P-12969 in the pathogenesis of AD. Methods: We assessed the differential expression of miRNA PC-5P-12969 in postmortem AD brains, AD animal and cell models using real-time reverse-transcriptase RT-PCR, we also checked the gene and protein expression of GSK3α and APP. Results: Our investigation revealed a notable upregulation of miRNA PC-5P-12969 in postmortem brains of AD patients, in transgenic mouse models of AD, and in mutant APP overexpressing-HT22 cells. Additionally, our findings indicate that overexpression of miRNA PC-5P-12969 exerts a protective effect on cell survival, while concurrently mitigating apoptotic cell death. Further-more, we established a robust and specific interaction between miRNA PC-5P-12969 and GSK3α. Our luciferase reporter assays provided confirmation of the binding between miRNA PC-5P-12969 and the 3'-UTR of the GSK3α gene. Manipulation of miRNA PC-5P-12969 levels in cellular models of AD yielded noteworthy alterations in the gene and protein expression levels of both GSK3α and APP. Remarkably, the manipulation of miRNA PC-5P-12969 levels yielded significant enhancements in mitochondrial respiration and ATP production, concurrently with a reduction in mitochondrial fragmentation, thus unveiling a potential regulatory role of miRNA PC-5P-12969 in these vital cellular processes. Conclusions: In summary, this study sheds light on the crucial role of miRNA PC-5P-12969 and its direct interaction with GSK3α in the context of AD.


Assuntos
Doença de Alzheimer , MicroRNAs , Camundongos , Animais , Humanos , Doença de Alzheimer/patologia , MicroRNAs/genética , MicroRNAs/metabolismo , Camundongos Transgênicos , Encéfalo/patologia , Regulação para Cima
3.
Biochim Biophys Acta Mol Basis Dis ; 1870(2): 166932, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37926360

RESUMO

Several converging lines of evidence from our group support a potential role of RLIP76 (AKA Rlip) in neurodegenerative disorders, including Alzheimer's Disease (AD). However, the role of Rlip in Alzheimer's and other neurodegenerative diseases is not well understood. The purpose of the present study is to determine the role of Rlip in the brains of AD patients and control subjects. To achieve our goals, we used frozen tissues and formalin-fixed paraffin-embedded postmortem brains from AD patients of different Braak stages and age-matched control subjects. Our immunohistology and immunoblotting blotting analysis revealed that expression of Rlip protein gradually and significantly decreased (p = 0.0001) with AD progression, being lowest in Braak stage IV-V. Rlip was colocalized with Amyloid beta (Aß) and phosphorylated tau (p-Tau) as observed by IHC staining and co-immunoprecipitation studies. Lipid peroxidation (4-HNE generation) and H2O2 production were significantly higher (p = 0.004 and 0.0001 respectively) in AD patients compared to controls, and this was accompanied by lower ATP production in AD (p = 0.0009). Oxidative DNA damage was measured by 8-Hydroxyguanosine (8-OHdG) in tissue lysates by ELISA and COMET assay. AD 8-OHdG levels were significantly higher (p = 0.0001) compared to controls. COMET assay was performed in brain cells, isolated from frozen postmortem samples. The control samples showed minimal DNA in comets representing few DNA strand breaks (<20 %), (score-0-1). However, the AD group showed an average of 50 % to 65 % of DNA in comet tails (score-4-5) indicating numerous DNA strand breaks. The difference between the two groups was significant (p = 0.001), as analyzed by Open Comet by ImageJ. Elevated DNA damage was further examined by western blot analysis for phosphorylated histone variant H2AX (γH2AX). Induction of γH2AX was very significant (p < 0.0001) and confirmed the presence of double-strand breaks in DNA. Overall, our results indicate an important role for Rlip in maintaining neuronal health and homeostasis by suppressing cellular oxidative stress and DNA damage. Based on our findings, we cautiously conclude that Rlip is a promising therapeutic target for Alzheimer's disease.


Assuntos
Doença de Alzheimer , Doenças Mitocondriais , Humanos , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Autopsia , Encéfalo/metabolismo , DNA/metabolismo , Peróxido de Hidrogênio/metabolismo , Doenças Mitocondriais/metabolismo , Estresse Oxidativo/fisiologia
5.
Cells ; 11(17)2022 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-36078067

RESUMO

In the current study, for the first time, we study mitophagy enhancer urolithin A and a combination of urolithin A+green tea extract EGCG against human Aß peptide-induced mitochondrial and synaptic, dendritic, inflammatory toxicities and behavioral changes in humanized homozygous amyloid beta knockin (hAbKI) mice of late-onset Alzheimer's disease (AD). Our findings reveal significantly increased positive effects of urolithin A and a combination treatment of urolithin A+EGCG in hAbKI mice for phenotypic behavioral changes including motor coordination, locomotion/exploratory activity, spatial learning and working memory. mRNA and protein levels of mitochondrial fusion, synaptic, mitophagy and autophagy genes were upregulated, and mitochondrial fission genes are downregulated in urolithin A and combine treatment in hAbKI mice; however, the effect is stronger in combined treatment. Immunofluorescence analysis of hippocampal brain sections shows similar findings of mRNA and protein levels. Mitochondrial dysfunction is significantly reduced in both treatment groups, but a stronger reduction is observed in combined treatment. Dendritic spines and lengths are significantly increased in both treatment groups, but the effect is stronger in combined treatment. The fragmented number of mitochondria is reduced, and mitochondrial length is increased, and mitophagosomal formations are increased in both the groups, but the effect is stronger in the combined treatment. The levels of amyloid beta (Aß) 40 and Aß42 are reduced in both treatments, however, the reduction is higher for combined treatment. These observations suggest that urolithin A is protective against human Aß peptide-induced toxicities; however, combined treatment of urolithin A+EGCG is effective and stronger, indicating that combined therapy is promising to treat late-onset AD patients.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Catequina/análogos & derivados , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Catequina/farmacologia , Cumarínicos , Humanos , Camundongos , Dinâmica Mitocondrial , RNA Mensageiro/metabolismo
6.
Int J Mol Sci ; 23(15)2022 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-35955694

RESUMO

Alzheimer's disease (AD) is one of the most common forms of neurodegeneration, defined by reduced cognitive function, which is caused by the gradual death of neurons in the brain. Recent studies have shown an age-dependent rise in the levels of voltage-dependent anion channel 1 (VDAC1) in AD. In addition, we discovered an aberrant interaction between VDAC1 and P-TAU in the brains of AD patients, which led to abnormalities in the structural and functional integrity of the mitochondria. The purpose of our study is to understand the protective effects of reduced VDAC1 against impaired mitochondrial dynamics and defective mitochondrial biogenesis in transgenic TAU mice. Recently, we crossed heterozygote VDAC1 knockout (VDAC1+/-) mice with transgenic TAU mice to obtain double-mutant VDAC1+/-/TAU mice. Our goal was to evaluate whether a partial decrease in VDAC1 lessens the amount of mitochondrial toxicity in transgenic Tau (P301L) mice. We found that mitochondrial fission proteins were significantly reduced, and mitochondrial fusion and biogenesis proteins were increased in double-mutant mice compared to TAU mice. On the basis of these discoveries, the current work may have significance for the development of reduced-VDAC1-based treatments for individuals suffering from AD as well as other tauopathies.


Assuntos
Doença de Alzheimer , Canal de Ânion 1 Dependente de Voltagem/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Animais , Modelos Animais de Doenças , Camundongos , Camundongos Transgênicos , Dinâmica Mitocondrial/genética , Proteínas Mitocondriais/metabolismo , Biogênese de Organelas , Canal de Ânion 1 Dependente de Voltagem/genética , Proteínas tau/genética , Proteínas tau/metabolismo
7.
Aging Cell ; 21(8): e13663, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35801276

RESUMO

Alzheimer's disease (AD) is the most common cause of mental dementia in the aged population. AD is characterized by the progressive decline of memory and multiple cognitive functions, and changes in behavior and personality. Recent research has revealed age-dependent increased levels of VDAC1 in postmortem AD brains and cerebral cortices of APP, APPxPS1, and 3xAD.Tg mice. Further, we found abnormal interaction between VDAC1 and P-Tau in the AD brains, leading to mitochondrial structural and functional defects. Our current study aimed to understand the impact of a partial reduction of voltage-dependent anion channel 1 (VDAC1) protein on mitophagy/autophagy, mitochondrial and synaptic activities, and behavior changes in transgenic TAU mice in Alzheimer's disease. To determine if a partial reduction of VDAC1 reduces mitochondrial and synaptic toxicities in transgenic Tau (P301L) mice, we crossed heterozygote VDAC1 knockout (VDAC1+/- ) mice with TAU mice and generated double mutant (VDAC1+/- /TAU) mice. We assessed phenotypic behavior, protein levels of mitophagy, autophagy, synaptic, other key proteins, mitochondrial morphology, and dendritic spines in TAU mice relative to double mutant mice. Partial reduction of VDAC1 rescued the TAU-induced behavioral impairments such as motor coordination and exploratory behavioral changes, and learning and spatial memory impairments in VDAC1+/- /TAU mice. Protein levels of mitophagy, autophagy, and synaptic proteins were significantly increased in double mutant mice compared with TAU mice. In addition, dendritic spines were significantly increased; the mitochondrial number was significantly reduced, and mitochondrial length was increased in double mutant mice. Based on these observations, we conclude that reduced VDAC1 is beneficial in symptomatic-transgenic TAU mice.


Assuntos
Doença de Alzheimer , Canal de Ânion 1 Dependente de Voltagem/metabolismo , Doença de Alzheimer/metabolismo , Animais , Autofagia , Modelos Animais de Doenças , Camundongos , Camundongos Transgênicos , Mitofagia/genética , Canal de Ânion 1 Dependente de Voltagem/genética , Proteínas tau/genética , Proteínas tau/metabolismo
8.
Int J Mol Sci ; 23(11)2022 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-35682775

RESUMO

Alzheimer's disease (AD) is a progressive neurodegenerative disorder and is the most common cause of dementia in older people. AD is associated with the loss of synapses, oxidative stress, mitochondrial structural and functional abnormalities, microRNA deregulation, inflammatory responses, neuronal loss, accumulation of amyloid-beta (Aß) and phosphorylated tau (p-tau). AD occurs in two forms: early onset, familial AD and late-onset, sporadic AD. Causal factors are still unknown for a vast majority of AD patients. Genetic polymorphisms are proposed to contribute to late-onset AD via age-dependent increases in oxidative stress and mitochondrial abnormalities. Recent research from our lab revealed that reduced levels of Rlip76 induce oxidative stress, mitochondrial dysfunction and synaptic damage, leading to molecular and behavioral phenotypes resembling late-onset AD. Rlip76 is a multifunctional 76 kDa protein encoded by the RALBP1 gene, located on chromosome 18. Rlip is a stress-protective ATPase of the mercapturic acid pathway that couples clathrin-dependent endocytosis with the efflux of glutathione-electrophile conjugates. Rlip is evolutionarily highly conserved across species and is ubiquitously expressed in all tissues, including AD-affected brain regions, the cerebral cortex and hippocampus, where highly active neuronal metabolisms render the cells highly susceptible to intracellular oxidative damage. In the current article, we summarize molecular and cellular features of Rlip and how depleted Rlip may exacerbate oxidative stress, mitochondrial dysfunction and synaptic damage in AD. We also discuss the possible role of Rlip in aspects of learning and memory via axonal growth, dendritic remodeling, and receptor regulation. We conclude with a discussion of the potential for the contribution of genetic polymorphisms in Rlip to AD progression and the potential for Rlip-based therapies.


Assuntos
Doença de Alzheimer , Idoso , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Humanos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Estresse Oxidativo , Sinapses/metabolismo
10.
Int J Mol Sci ; 23(10)2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-35628323

RESUMO

Despite successful virologic control with combination antiretroviral therapy (cART), about half of people living with the human immunodeficiency virus-1 (HIV) develop an HIV-associated neurocognitive disorder (HAND). It is estimated that 50% of individuals who are HIV-positive in the United States are aged 50 years or older. Therefore, a new challenge looms as individuals living with HIV increase in age. There is concern that Alzheimer's disease (AD) may become prevalent with an earlier onset of cognitive decline in people living with HIV (PLWH). Clinical data studies reported the presence of AD biomarkers in PLWH. However, the functional significance of the interaction between HIV or HIV viral proteins and AD biomarkers is still not well studied. The main goal of the present study is to address this knowledge gap by determining if the HIV envelope glycoprotein 120 (HIV-gp120) can affect the cognitive functions in the Tau mouse AD model. Male Tau and age-matched, wild-type (WT) control mice were treated intracerebroventricularly (ICV) with HIV-gp120. The animals were evaluated for cognitive function using a Y-maze. We found that HIV-gp120 altered cognitive function in Tau mice. Notably, HIV-gp120 was able to promote a cognitive decline in transgenic Tau (P301L) mice compared to the control (HIV-gp120 and WT). We provide the first in vivo evidence of a cognitive interaction between an HIV viral protein and Tau mice.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Infecções por HIV , HIV-1 , Doença de Alzheimer/tratamento farmacológico , Animais , Antígenos Virais , Biomarcadores , Modelos Animais de Doenças , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Humanos , Masculino , Camundongos
11.
Cells ; 11(4)2022 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-35203382

RESUMO

The purpose of our study is to investigate early cellular, molecular, morphological and behavioral changes in humanized amyloid-beta-knock-in (hAbKI) mice. Using seven-month-old homozygous hAbKI mice, we studied behavioral phenotype parameters, including spatial learning and memory (Morris Water Maze), locomotor activity (open field), working memory (Y-maze) and motor coordination (rotarod); mRNA abundance, protein levels, soluble amyloid-beta 40 and 42 levels and regional immunoreactivities of key markers of mitochondrial dynamics, mitochondrial biogenesis, synaptic health, mitophagy and autophagy; mitochondrial function and using transmission electron microscopy & Golgi-Cox staining, we assessed mitochondrial morphology and dendritic spines. Our extensive behavioral analysis revealed that seven-month-old hAbKI mice showed impairments in motor coordination, reduced locomotor and exploration activities, impairments in working memory and spatial learning and memory. Our mRNA and protein analyses revealed the increased expression of mitochondrial-fission genes and reduced expression of mitochondrial-fusion, mitochondrial-biogenesis, synaptic, autophagy and mitophagy genes in seven-month-old hAbKI mice. An immunofluorescence analysis revealed altered immunoreactivities and agreed with the immunoblot results. Transmission-electron-microscopy data revealed increased mitochondrial fragmentation and reduced mitochondrial length in both hippocampal and cortical tissues of seven-month-old hAbKI mice and mitochondrial function defective. A Golgi-Cox-staining analysis revealed reduced dendritic spines in both cerebral cortices and hippocampi of hAbKI mice. Soluble amyloid-beta (1-40 and 1-42) were detected in three-month-old hAbKI mice and progressively increased in seven-month-old mice. These observations suggest that the human amyloid-beta peptide is sufficient to cause behavioral, mitochondrial, synaptic and ultrastructural changes in seven-month-old hAbKI mice. Our study findings also suggest that hAbKI mice might serve as a model for preclinical studies of preventive therapies.


Assuntos
Doença de Alzheimer , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Modelos Animais de Doenças , Camundongos , Camundongos Transgênicos , Neurônios/metabolismo , RNA Mensageiro/metabolismo
12.
Hum Mol Genet ; 31(7): 1022-1034, 2022 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-34559191

RESUMO

The purpose of our study is to determine DDQ (diethyl (3,4-dihydroxyphenethylamino) (quinolin-4-yl) methylphosphonate)-a newly discovered molecule that has been shown to protect against phosphorylated tau (p-tau) in Alzheimer's disease (AD) pathogenesis. We used a well-studied tau (P301L) transgenic mouse model to achieve our goal. We administered DDQ into 12-month-old Tau mice, at 20 mg/kg body weight intraperitoneally two times per week for 2 months. We also assessed DDQ levels in the blood, skeletal muscle and brain using biochemical and molecular techniques. We investigated the mRNA and protein levels of mitochondrial dynamics, biogenesis, synaptic, p-tau and longevity genes sirtuins in DDQ-treated tau mice using real-time quantitative PCR (q-RT-PCR), immunoblotting and immunofluorescence techniques. Our extensive pharmacodynamics investigations revealed that skeletal muscle had the greatest peak levels of DDQ, followed by serum and brain. Interestingly, DDQ-treated tau mice had higher levels of mitochondrial fusion, biogenesis, synaptic genes and sirtuins than DDQ-untreated tau mice. In addition, DDQ-treated tau mice had lower levels of mitochondrial fission and p-tau than untreated tau mice. The current findings, combined with our prior findings, firmly show that DDQ possesses anti-aging, anti-amyloid-beta and anti-p-tau properties, making it a promising molecule for reducing age-related, amyloid-beta and p-tau-induced synaptic and mitochondrial toxicities in AD.


Assuntos
Doença de Alzheimer , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Modelos Animais de Doenças , Camundongos , Camundongos Transgênicos , Mitocôndrias/metabolismo , Neurônios/metabolismo , Sinapses/metabolismo , Proteínas tau/genética , Proteínas tau/metabolismo
13.
J Alzheimers Dis ; 85(1): 207-221, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34776453

RESUMO

BACKGROUND: DNA damage accumulation and mitochondrial abnormalities are elevated in neurons during aging and may contribute to neurodegenerative pathologic conditions such as Alzheimer's disease. BRCA1 interacting protein 1 or BRIP1 is a 5' to 3' DNA helicase that catalyzes many abnormal DNA structures during DNA replication, gene transcription, and recombination, and contribute to genomic integrity. OBJECTIVE: BRIP1 functions were reasonably well studied in DNA repair; however, there is limited data on its role and regulation during aging and neurodegenerative diseases. METHODS: We used immunohistochemistry, western blot, and qRT-PCR assays to analyze the expression of BRIP1. Immunofluorescence studies were performed to study the formation of R-loops, reactive oxygen species (ROS) generation, and mitochondrial morphology. Flow cytometry and transmission electron microscopy were used to evaluate mitochondrial ROS and mitochondrial structures, respectively. Oxygen consumption rate was measured using Seahorse, and the Presto Blue™ assays were used to evaluate cell viability. RESULTS: Our results demonstrate the expression of BRIP1 in mouse and human brain tissues and in neuronal cell lines. BRIP1 levels were elevated in the hippocampal regions of the brains, specifically in the dentate gyrus. BRIP1 downregulation in neuronal cells caused increased R-loop formation basally and in response to H2O2 treatment. Furthermore, BRIP1 deficient cells exhibited elevated levels of excitotoxicity induced by L-Glutamic acid exposure as evidenced by (mitochondrial) ROS levels, deteriorated mitochondrial health, and cell death compared to BRIP1 proficient neuronal cells. CONCLUSION: Overall, our results indicate an important role for BRIP1 in maintaining neuronal cell health and homeostasis by suppressing cellular oxidative stress.


Assuntos
Encéfalo/patologia , Dano ao DNA , Proteínas de Grupos de Complementação da Anemia de Fanconi/genética , Neurônios/metabolismo , RNA Helicases/genética , Animais , Linhagem Celular , Sobrevivência Celular , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Doenças Neurodegenerativas/genética , Neurônios/patologia , Estresse Oxidativo/genética
14.
Cells ; 10(11)2021 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-34831336

RESUMO

The purpose of our study is to understand the role of the RALBP1 gene in oxidative stress (OS), mitochondrial dysfunction and cognition in Alzheimer's disease (AD) pathogenesis. The RALPB1 gene encodes the 76 kDa protein RLIP76 (Rlip). Rlip functions as a stress-responsive/protective transporter of glutathione conjugates (GS-E) and xenobiotic toxins. We hypothesized that Rlip may play an important role in maintaining cognitive function. The aim of this study is to determine whether Rlip deficiency in mice is associated with AD-like cognitive and mitochondrial dysfunction. Brain tissue obtained from cohorts of wildtype (WT) and Rlip+/- mice were analyzed for OS markers, expression of genes that regulate mitochondrial fission/fusion, and synaptic integrity. We also examined mitochondrial ultrastructure in brains obtained from these mice and further analyzed the impact of Rlip deficiency on gene networks of AD, aging, stress response, mitochondrial function, and CREB signaling. Our studies revealed a significant increase in the levels of OS markers and alterations in the expression of genes and proteins involved in mitochondrial biogenesis, dynamics and synapses in brain tissues from these mice. Furthermore, we compared the cognitive function of WT and Rlip+/- mice. Behavioral, basic motor and sensory function tests in Rlip+/- mice revealed cognitive decline, similar to AD. Gene network analysis indicated dysregulation of stress-activated gene expression, mitochondrial function and CREB signaling genes in the Rlip+/- mouse brain. Our results suggest that Rlip deficiency-associated increases in OS and mitochondrial dysfunction could contribute to the development or progression of OS-related AD processes.


Assuntos
Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Proteínas Ativadoras de GTPase/metabolismo , Mitocôndrias/patologia , Estresse Oxidativo , Animais , Antioxidantes/metabolismo , Comportamento Animal , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Modelos Animais de Doenças , Proteínas Ativadoras de GTPase/deficiência , Regulação da Expressão Gênica , Camundongos , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Dinâmica Mitocondrial/genética , Modelos Biológicos , Biogênese de Organelas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais , Sinapses/genética
15.
Free Radic Biol Med ; 172: 652-667, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34246776

RESUMO

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by memory loss and multiple cognitive impairments. AD is marked by multiple cellular changes, including deregulation of microRNAs, activation of glia and astrocytes, hormonal imbalance, defective mitophagy, synaptic degeneration, in addition to extracellular neuritic amyloid-beta (Aß) plaques, phosphorylated tau (P-tau), and intracellular neurofibrillary tangles (NFTs). Recent research in AD revealed that defective synaptic mitophagy leads to synaptic degeneration and cognitive dysfunction in AD neurons. Our critical analyses of mitochondria and Aß and P-tau revealed that increased levels of Aß and P-Tau, and abnormal interactions between Aß and Drp1, P-Tau and Drp1 induced increased mitochondrial fragmentation and proliferation of dysfunctional mitochondria in AD neurons and depleted Parkin and PINK1 levels. These events ultimately lead to impaired clearance of dead and/or dying mitochondria in AD neurons. The purpose of our article is to highlight the recent research on mitochondria and synapses in relation to Aß and P-tau, focusing on recent developments.


Assuntos
Doença de Alzheimer , Doenças Neurodegenerativas , Envelhecimento , Peptídeos beta-Amiloides , Humanos , Mitocôndrias , Mitofagia , Sinapses , Proteínas tau
16.
Mitochondrion ; 59: 17-29, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33839321

RESUMO

The purpose of our study is to determine the protective effects of the newly discovered molecule DDQ (diethyl (3,4-dihydroxyphenethylamino)(quinolin-4-yl) methylphosphonate) against mutant APP and amyloid-beta (Aß) in Alzheimer's disease (AD). To achieve our objective, we used a well characterized amyloid-beta precursor protein (APP) transgenic mouse model (Tg2576 strain). We administered DDQ, a 20 mg/kg body weight (previously determined in our laboratory) intra-peritoneally 3-times per week for 2 months, starting at the beginning of the 12th month, until the end of the 14th month. Further, using biochemical and molecular methods, we measured the levels of DDQ in the blood, skeletal muscle, and brain. Using Morris Water Maze, Y-maze, open field, and rotarod tests, we assessed cognitive behavior after DDQ treatment. Using q-RT-PCR, immunoblotting, transmission electron microscopy, and Golgi-cox staining methods, we studied mRNA and protein levels of longevity genes SIRTUINS, mitochondrial number & length, and dendritic spine number and length in DDQ-treated APP mice. Our extensive pharmacodynamics analysis revealed high peak levels of DDQ in the skeletal muscle, followed by serum and brain. Our behavioral analysis of rotarod, open field, Y-maze, and Morris Water Maze tests revealed that DDQ ameliorated cognitive decline (Morris Water Maze), improved working memory (Y-Maze), exploratory behavior (open field), and motor coordination (rotarod) in DDQ-treated APP mice. Interestingly, longevity genes SIRTUINS, mitochondrial biogenesis, fusion, mitophagy, autophagy and synaptic genes were upregulated in DDQ-treated APP mice relative to untreated APP mice. Dendritic spines and the quality mitochondria were significantly increased in DDQ treated APP mice. Current study findings, together with our previous study observations, strongly suggest that DDQ has anti-aging, and anti-amyloid-beta effects and a promising molecule to reduce age-and amyloid-beta-induced toxicities in AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Bibliotecas de Moléculas Pequenas/administração & dosagem , Doença de Alzheimer/sangue , Doença de Alzheimer/genética , Doença de Alzheimer/psicologia , Precursor de Proteína beta-Amiloide/efeitos dos fármacos , Animais , Cognição/efeitos dos fármacos , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Injeções Intraperitoneais , Camundongos , Camundongos Transgênicos , Microscopia Eletrônica de Transmissão , Teste do Labirinto Aquático de Morris/efeitos dos fármacos , Mutação , Sirtuínas/genética , Sirtuínas/metabolismo , Bibliotecas de Moléculas Pequenas/farmacocinética
17.
Immunogenetics ; 73(4): 291-305, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33754173

RESUMO

Type 2 diabetes mellitus (T2DM) is a disease with polygenic inheritance. The expression of major histocompatibility complex class II genes are regulated by several trans-activators. We have studied the expression of HLA-DRB1, RFX, CIITA-P1, PIV transactivators, immunophenotyping of cells, SNPs in CIITA-168 (A/G) and IFN-γ + 874 (T/A) in T2DM patients and controls (n = 201 each). We observed increased frequencies of DRB1*03, DRB1*04 and DRB1*07 and decreased frequencies of DRB1*10, DRB1*14, and DRB1*15 alleles among patients. Significant up-regulations of HLA-DRB1 genes were observed in patients (p < 0.0001). Down-regulated expressions were documented in DRB1*03-homo (p < 0.002) and DRB1*04-homo (p < 0.009) patients. No significant differences were observed for CIITA-P1 expression except DRB1*04-pooled (p < 0.0113). The CIITA-PIV was up-regulated in overall (p < 0.0001), DRB1*03-pooled (p < 0.0006), DRB1*03-hetero (p < 0.0006) and DRB1*03-homo (p < 0.001) T2DM patients. However, significant down-regulations were documented for DRB1*04-pooled (p < 0.040), DRB1*04-hetero (p < 0.060), and DRB1*04-homo (p < 0.027) combinations. Further, significant down-regulations of RFX5 were observed in overall (p < 0.0006), DRB1*04-pooled (p < 0.0022), and DRB1*04-hetero (p < 0.0004) combinations. Immunophenotyping studies revealed significant increase of CD45+ CD14-, CD19+, CD14- and CD8 cells and elevated level of expression of IFN-γ (p < 0.0001) in patients. A significant increase of TT (p < 3.35 × 10-6) and decrease of TA (p < 4.57 × 10-4) genotypes of IFN-γ + 874 (T/A) and an increase of GG (p < 0.001) and decrease of AG (p < 8.24 × 10-5) genotypes of CIITA-168 A/G SNPs were observed. The combinatorial analysis revealed susceptible associations for DRB1*03 + AA, *03 + AG, *03 + GG and *04 + GG and protective associations for DRB1*10 + AG, *10 + GG, *15 + AG, and *14 + GG combinations. Thus, the present study corroborated the effect of differential expressions of promoters of risk alleles in the pathogenesis of T2DM.


Assuntos
Diabetes Mellitus Tipo 2/patologia , Predisposição Genética para Doença , Cadeias HLA-DRB1/genética , Proteínas Nucleares/metabolismo , Polimorfismo de Nucleotídeo Único , Transativadores/metabolismo , Adulto , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Nucleares/genética , Transativadores/genética
18.
Mol Neurobiol ; 58(7): 3588-3600, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33768469

RESUMO

The purpose of our study is to determine the protective effects of the newly discovered molecule DDQ (diethyl (3,4-dihydroxyphenethylamino)(quinolin-4-yl) methylphosphonate) against aging in an in vitro, mouse primary hippocampal neurons, HT22 cells, and in vivo, 24-month-old C57BL6/J mice. Using biochemical and molecular methods, we studied the half-life period in the blood and brain, optimized the dose, determined dose-response (using 1, 5, 10, 20, and 50 mg/kg body weight), and measured the levels of blood, skeletal muscle, and brain. Using Morris water maze (cognitive behavior), q-RT-PCR (mRNA and protein levels of longevity genes SIRTUINS), transmission electron microscopy (mitochondrial number and length), and Golgi-Cox staining (dendritic spine number and length) were assessed in 24-month-old C57BL6/J mice. Out of 5 different doses of DDQ, the 20 mg/kg body weight dose showed the strongest protective effects against aging in C57BL6/J mice. The half-life time of DDQ is 20 h in the serum and 12 h in the brain. Our extensive pharmacodynamics analysis revealed high peak levels of DDQ in the skeletal muscle, followed by serum and brain. Using mouse primary hippocampal (HT22) neurons and 24-month-old C57BL6/J mice, we tested the protective effects of DDQ. Interestingly, longevity genes SIRTUINS were upregulated in DDQ-treated HT22 cells, and DDQ-treated aged wild-type mice relative to DDQ-untreated cells and untreated aged control mice. Dendritic spines and the quality of mitochondria were significantly increased in DDQ-treated aged mice. Current study findings, together with our previous study observations, strongly suggest that DDQ has anti-aging effects and warrants further investigations of anti-inflammatory, anti-DNA damage, and telomerase activity studies.


Assuntos
Envelhecimento/efeitos dos fármacos , Antioxidantes/farmacologia , Encéfalo/efeitos dos fármacos , Dopaminérgicos/farmacologia , Envelhecimento/metabolismo , Animais , Antioxidantes/química , Encéfalo/metabolismo , Linhagem Celular , Dopaminérgicos/química , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/efeitos dos fármacos , Neurônios/metabolismo
19.
Mitochondrion ; 58: 49-58, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33639273

RESUMO

Type 2 Diabetes mellitus (T2DM) has become a major public health issue associated with a high risk of late-onset Alzheimer's disease (LOAD). Mitochondrial dysfunction is one of the molecular events that occur in the LOAD pathophysiology. The present study was planned to investigate the molecular alterations induced by hyperglycemia in the mitochondria of diabetic mice and further explore the possible ameliorative role of the mitochondria-targeted small peptide, SS31 in diabetic mice. For this purpose, we used a polygenic mouse model of type 2 diabetes, TALLYHO/JngJ (TH), and nondiabetic, SWR/J mice strains. The diabetic status in TH mice was confirmed at 8 weeks of age. The 24 weeks old experimental animals were segregated into three groups: Non-diabetic controls (SWR/J mice), diabetic (TH mice) and, SS31 treated diabetic TH mice. The mRNA and protein expression levels of mitochondrial proteins were investigated in all the study groups in the liver tissues using qPCR and immunoblot analysis. Also, the mitochondrial functions including H2O2 production, ATP generation, and lipid peroxidation were assessed in all the groups. Mitochondrial dysfunction was observed in TH mice as evident by significantly elevated H2O2 production, lipid peroxidation, and reduced ATP production. The mRNA expression and Western blot analysis of mitochondrial dynamics (Drp1 and Fis1 - fission; Mfn1, Mfn2, and Opa1 -fusion), and biogenesis (PGC-1α, Nrf1, Nrf2, and TFAM) genes were significantly altered in diabetic TH mice. Furthermore, SS31 treatment significantly reduced the mitochondrial abnormalities and restore mitochondrial functions in diabetic TH mice.


Assuntos
Diabetes Mellitus Experimental/patologia , Hiperglicemia/patologia , Fígado/patologia , Mitocôndrias Hepáticas/efeitos dos fármacos , Oligopeptídeos/farmacologia , Animais , Peso Corporal/efeitos dos fármacos , Diabetes Mellitus Experimental/metabolismo , Hiperglicemia/metabolismo , Fígado/metabolismo , Masculino , Camundongos , Mitocôndrias Hepáticas/metabolismo , Dinâmica Mitocondrial/efeitos dos fármacos
20.
Infect Genet Evol ; 89: 104685, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33359263

RESUMO

The distribution of HLA class-II DRB1* and DQB1* alleles/ haplotypes were studied in 438 individuals of 8 Dravidian tribal groups inhabiting the Western Ghats, south India. The HLA typing was performed by PCR-SSP method. In order to identify the 5-locus Ancestral Extended Haplotypes (AEH), the alleles of HLA-A, -B and -C loci were typed for DNAs with predominant 2-locus haplotypes. The analyses have revealed allele HLA-DRB1*15 as the most predominant allele (Lowest / Highest range: Urali, 14.81 / Malasar, 48.94), followed by the alleles DRB1*10 (Katunayakan, 1.85 / Paliyan, 48.21), DRB1*14 (Paliyan 4.46 / Katunayakan, 40.74), DRB1*12 (Mannan, 1.64 / Katunayakan, 20.37) and DRB1*03 (Mannan, 1.64 / Urali, 29.63). The most frequent DQB1* alleles were DQB1*02 (Paliyan 3.57 / Urali, 23.15), DQB1*05 (Katunayakan, 27.77 / Paliyan 84.82) and DQB1*06 (Malasar, 8.51 / Kuruman, 33.51). The most predominant two-locus haplotypes observed were DRB1*15-DQB1*05, DRB1*10-DQB1*05, DRB1*15-DQB1*06 and DRB1*04-DQB1*05. The present study of HLA immunogenetics of south Indian tribes have revealed the presence of globally shared two and 5-locus haplotypes. Many of these haplotypes were implicated in a number of diseases in south India. We observed the presence of ancestral extended haplotypes (AEHs), hitherto not reported in Indian populations such as, A*68-B*35-C*02-DRB1*15:01-DQB1*05:01, A*24-B*57-C*06-DRB1*04:01-DQB1*05:01 and A*24-B*35-C*02-DRB1*15:01-DQB1*05:02. The dendrogram based phylogenetic analyses have revealed the Caucasian affinity of Urali, palaeo-Mediterranean and Indo-European affinity of Malasar tribes. The presence of globally shared susceptible and protective haplotypes reiterated the mosaic immunogenetic fabric of south Indian tribes.


Assuntos
Etnicidade/genética , Frequência do Gene , Predisposição Genética para Doença , Cadeias beta de HLA-DQ/genética , Cadeias HLA-DRB1/genética , Haplótipos , Adulto , Evolução Molecular , Feminino , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Filogenia
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