scholarly journals Molecular inflection points in the aging human brain

2018 ◽  
Author(s):  
Eden Deng
Keyword(s):  
Gene Expression ◽  
Human Brain ◽  
Neurodegenerative Diseases ◽  
Aging Process ◽  
Brain Research ◽  
Piecewise Linear ◽  
Human Microglia ◽  
Age Related ◽  
Inflection Points ◽  
Age Dependent

ABSTRACTThe onset of neurodegenerative diseases has been associated with age-dependent changes of gene expression in the brain. Research on age-dependent genes commonly assumes gradual linear relationships between gene expression and aging, failing to identify sudden changes in gene expression that may provide insight into the aging process and its role in neurodegenerative diseases. Here, a piecewise linear regression model is proposed to identify critical inflection points at which aging mechanisms may accelerate. Age-related gene expression data from tissue of four regions of the human brain (frontal cortex, hippocampus, putamen, substantia nigra) and human microglia were analyzed for inflection points. The best piecewise model represented stable expression during younger ages followed by an increase or decrease with age after the inflection point. In brain tissue, genes showing inflection points in expression pattern were enriched for gene ontology terms involved in neurodegenerative diseases. The hippocampus showed the highest proportion of genes with inflection points and the lowest variability in inflection points. These findings suggest that inflection points in gene expression may be used to characterize the aging process in the human brain and may help identify markers for the onset of neurodegenerative diseases.

scholarly journals Genetic control of age-related gene expression and complex traits in the human brain

2017 ◽  
Author(s):  
Trevor Martin ◽  
Hunter B. Fraser
Keyword(s):  
Gene Expression ◽  
Human Brain ◽  
Neurodegenerative Diseases ◽  
Genetic Variants ◽  
Complex Traits ◽  
Molecular Mechanisms ◽  
Neurological Diseases ◽  
Expression Patterns ◽  
Related Gene ◽  
Age Related

AbstractAge is the primary risk factor for many of the most common human diseases—particularly neurodegenerative diseases—yet we currently have a very limited understanding of how each individual’s genome affects the aging process. Here we introduce a method to map genetic variants associated with age-related gene expression patterns, which we call temporal expression quantitative trait loci (teQTL). We found that these loci are markedly enriched in the human brain and are associated with neurodegenerative diseases such as Alzheimer’s disease and Creutzfeldt-Jakob disease. Examining potential molecular mechanisms, we found that age-related changes in DNA methylation can explain some cis-acting teQTLs, and that trans-acting teQTLs can be mediated by microRNAs. Our results suggest that genetic variants modifying age-related patterns of gene expression, acting through both cis- and trans-acting molecular mechanisms, could play a role in the pathogenesis of diverse neurological diseases.

scholarly journals Integrated analysis of the aging brain transcriptome and proteome in tauopathy

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Carl Grant Mangleburg ◽  
Timothy Wu ◽  
Hari K. Yalamanchili ◽  
Caiwei Guo ◽  
Yi-Chen Hsieh ◽  
...  
Keyword(s):  
Gene Expression ◽  
Human Brain ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Differentially Expressed ◽  
Integrated Analysis ◽  
Mutant Form ◽  
Brain Gene Expression ◽  
Brain Transcriptome ◽  
Age Dependent

Abstract Background Tau neurofibrillary tangle pathology characterizes Alzheimer’s disease and other neurodegenerative tauopathies. Brain gene expression profiles can reveal mechanisms; however, few studies have systematically examined both the transcriptome and proteome or differentiated Tau- versus age-dependent changes. Methods Paired, longitudinal RNA-sequencing and mass-spectrometry were performed in a Drosophila model of tauopathy, based on pan-neuronal expression of human wildtype Tau (TauWT) or a mutant form causing frontotemporal dementia (TauR406W). Tau-induced, differentially expressed transcripts and proteins were examined cross-sectionally or using linear regression and adjusting for age. Hierarchical clustering was performed to highlight network perturbations, and we examined overlaps with human brain gene expression profiles in tauopathy. Results TauWT induced 1514 and 213 differentially expressed transcripts and proteins, respectively. TauR406W had a substantially greater impact, causing changes in 5494 transcripts and 697 proteins. There was a ~ 70% overlap between age- and Tau-induced changes and our analyses reveal pervasive bi-directional interactions. Strikingly, 42% of Tau-induced transcripts were discordant in the proteome, showing opposite direction of change. Tau-responsive gene expression networks strongly implicate innate immune activation. Cross-species analyses pinpoint human brain gene perturbations specifically triggered by Tau pathology and/or aging, and further differentiate between disease amplifying and protective changes. Conclusions Our results comprise a powerful, cross-species functional genomics resource for tauopathy, revealing Tau-mediated disruption of gene expression, including dynamic, age-dependent interactions between the brain transcriptome and proteome.

scholarly journals Metabolomics of Human Brain Aging and Age-Related Neurodegenerative Diseases

2014 ◽  
Vol 73 (7) ◽  
pp. 640-657 ◽  
Author(s):  
Mariona Jové ◽  
Manuel Portero-Otín ◽  
Alba Naudí ◽  
Isidre Ferrer ◽  
Reinald Pamplona
Keyword(s):  
Human Brain ◽  
Neurodegenerative Diseases ◽  
Brain Aging ◽  
Age Related

scholarly journals Age-Dependent Changes in Synaptic NMDA Receptor Composition in Adult Human Cortical Neurons

2020 ◽  
Vol 30 (7) ◽  
pp. 4246-4256 ◽  
Author(s):  
Chrysia M Pegasiou ◽  
Ardalan Zolnourian ◽  
Diego Gomez-Nicola ◽  
Katrin Deinhardt ◽  
James A R Nicoll ◽  
...  
Keyword(s):  
Human Brain ◽  
Cortical Neurons ◽  
Critical Role ◽  
Memory Storage ◽  
Neurosurgical Procedures ◽  
Adult Human ◽  
Age Related ◽  
Human Neurons ◽  
Age Dependent ◽  
Cortical Synapses

Abstract The molecular processes underlying the aging-related decline in cognitive performance and memory observed in humans are poorly understood. Studies in rodents have shown a decrease in N-methyl-D-aspartate receptors (NMDARs) that contain the GluN2B subunit in aging synapses, and this decrease is correlated with impaired memory functions. However, the age-dependent contribution of GluN2B-containing receptors to synaptic transmission in human cortical synapses has not been previously studied. We investigated the synaptic contribution of GluN2A and GluN2B-containing NMDARs in adult human neurons using fresh nonpathological temporal cortical tissue resected during neurosurgical procedures. The tissue we obtained fulfilled quality criteria by the absence of inflammation markers and proteomic degradation. We show an age-dependent decline in the NMDA/AMPA receptor ratio in adult human temporal cortical synapses. We demonstrate that GluN2B-containing NMDA receptors contribute to synaptic responses in the adult human brain with a reduced contribution in older individuals. With previous evidence demonstrating the critical role of synaptic GluN2B in regulating synaptic strength and memory storage in mice, this progressive reduction of GluN2B in the human brain during aging may underlie a molecular mechanism in the age-related decline in cognitive abilities and memory observed in humans.

scholarly journals Genetic Evidence Linking Age-Dependent Attenuation of the 26S Proteasome with the Aging Process

2008 ◽  
Vol 29 (4) ◽  
pp. 1095-1106 ◽  
Author(s):  
Ayako Tonoki ◽  
Erina Kuranaga ◽  
Takeyasu Tomioka ◽  
Jun Hamazaki ◽  
Shigeo Murata ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Life Span ◽  
Cellular Protein ◽  
Proteasome Activity ◽  
26S Proteasome ◽  
Loss Of Function ◽  
Ubiquitinated Proteins ◽  
Age Related ◽  
Age Dependent ◽  
Progressive Neurodegeneration

ABSTRACT The intracellular accumulation of unfolded or misfolded proteins is believed to contribute to aging and age-related neurodegenerative diseases. However, the links between age-dependent proteotoxicity and cellular protein degradation systems remain poorly understood. Here, we show that 26S proteasome activity and abundance attenuate with age, which is associated with the impaired assembly of the 26S proteasome with the 19S regulatory particle (RP) and the 20S proteasome. In a genetic gain-of-function screen, we characterized Rpn11, which encodes a subunit of the 19S RP, as a suppressor of expanded polyglutamine-induced progressive neurodegeneration. Rpn11 overexpression suppressed the age-related reduction of the 26S proteasome activity, resulting in the extension of flies' life spans with suppression of the age-dependent accumulation of ubiquitinated proteins. On the other hand, the loss of function of Rpn11 caused an early onset of reduced 26S proteasome activity and a premature age-dependent accumulation of ubiquitinated proteins. It also caused a shorter life span and an enhanced neurodegenerative phenotype. Our results suggest that maintaining the 26S proteasome with age could extend the life span and suppress the age-related progression of neurodegenerative diseases.

scholarly journals Age dependent changes in synaptic NMDA receptor composition in adult human cortical neurons

2020 ◽  
Author(s):  
C.M. Pegasiou ◽  
A. Zolnourian ◽  
D. Gomez-Nicola ◽  
K. Deinhardt ◽  
J.A.R. Nicoll ◽  
...  
Keyword(s):  
Human Brain ◽  
Cortical Neurons ◽  
Critical Role ◽  
Memory Storage ◽  
Neurosurgical Procedures ◽  
Adult Human ◽  
Age Related ◽  
Human Neurons ◽  
Age Dependent ◽  
Cortical Synapses

AbstractThe molecular processes underlying the ageing-related decline in cognitive performance and memory observed in humans are poorly understood. Studies in rodents have shown a decrease in N-methyl-D-aspartate receptors (NMDARs) that contain the GluN2B subunit in ageing synapses, and this decrease is correlated with impaired memory functions. However, the age-dependent contribution of GluN2B containing receptors to synaptic transmission in human cortical synapses has not been previously studied. We investigated the synaptic contribution of GluN2A and GluN2B containing NMDARs in adult human neurons using fresh non-pathological temporal cortical tissue resected during neurosurgical procedures. The tissue we obtained fulfilled quality criteria by the absence of inflammation markers and proteomic degradation. We show an age-dependent decline in the NMDA/AMPA receptor ratio in adult human temporal cortical synapses. We demonstrate that GluN2B containing NMDA receptors contribute to synaptic responses in the adult human brain with a reduced contribution in older individuals. With previous evidence demonstrating the critical role of synaptic GluN2B in regulating synaptic strength and memory storage in mice, this progressive reduction of GluN2B in the human brain during ageing may underlie a molecular mechanism in the age-related decline in cognitive abilities and memory observed in humans.

scholarly journals Cranial Manipulation Affects Cholinergic Pathway Gene Expression in an Animal Model of Age-related Cognitive Decline

2020 ◽  
Author(s):  
Ramu Anandakrishnan ◽  
Hope Tobey ◽  
Steven Nguyen ◽  
Osscar Gonzalez Sandoval ◽  
Bradley G. Klein ◽  
...  
Keyword(s):  
Gene Expression ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Animal Model ◽  
Nervous System ◽  
Cognitive Decline ◽  
Fold Change ◽  
Age Related ◽  
Age Dependent ◽  
Age Related Cognitive Decline

Abstract Age dependent dementia is a devastating disorder afflicting the growing older population around the world. Although pharmacological agents improve symptoms of dementia, age related co-morbidities combined with adverse effects often outweigh their clinical benefits. Therefore, non-pharmacological therapies are being investigated as an alternative. Randomized controlled trials and observational studies have shown promising results for cranial manipulation as a treatment for dementia and other nervous system disorders. In this study we examine the effect of osteopathic cranial manipulative medicine (OCMM) on gene expression, in an animal model for age-related cognitive decline (aged rats). We found that OCMM significantly affected the expression of 36 genes in the neuronal pathway (False Discovery Rate (FDR) < 0.004). The top five neuronal genes with the largest fold-change (Slc5a7, Chat, Slc18a3, Adcy5 and Cacna2d2, >2-fold change, FDR<0.004) are part of the cholinergic neurotransmission mechanism, which is known to affect cognitive function. Slc5a7, the highest overexpressed neuronal gene (3-fold change) encodes a sodium and chloride ion-dependent high-affinity transporter that mediates choline uptake for acetylcholine synthesis in cholinergic neurons. This is the pathway enhanced by the clinically used Alzheimer’s disease drug Donepezil, which selectively inhibits acetylcholinesterase, an enzyme that catalyzes endogenous acetylcholine degradation. In addition, 40% of significant differentially expressed (SDE) genes (FDR<0.004), have been previously implicated in neurological disorders. Overall, SDE genes and their role in central nervous system signaling pathways suggest a connection to previously reported OCMM induced behavioral and biochemical changes in rat models of age-dependent dementia. Further investigation in this direction will provide a better understanding of the molecular mechanisms of OCMM and its potential in clinical applications. With clinical validation, OCMM could represent a much needed low-risk adjunct treatment for age-related dementia including Alzheimer’s disease.

scholarly journals Integrated analysis of the aging brain transcriptome and proteome in tauopathy

2020 ◽  
Author(s):  
Carl Grant Mangleburg ◽  
Timothy Wu ◽  
Hari K. Yalamanchili ◽  
Caiwei Guo ◽  
Yi-Chen Hsieh ◽  
...  
Keyword(s):  
Gene Expression ◽  
Human Brain ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Differentially Expressed ◽  
Integrated Analysis ◽  
Aging Brain ◽  
Brain Gene Expression ◽  
Brain Transcriptome ◽  
Age Dependent

AbstractBackgroundTau neurofibrillary tangle pathology characterizes Alzheimer’s disease and other neurodegenerative tauopathies. Brain gene expression profiles can reveal mechanisms; however, few studies have systematically examined both the transcriptome and proteome or differentiated Tau- versus age-dependent changes.MethodsPaired, longitudinal RNA-sequencing and mass-spectrometry were performed in a Drosophila model of tauopathy, based on pan-neuronal expression of human wildtype Tau (TauWT) or a mutation causing frontotemporal dementia (TauR406W). Tau-induced, differentially expressed transcripts and proteins were examined cross-sectionally or using linear regression and adjusting for age. Hierarchical clustering was performed to highlight network perturbations, and we examined overlaps with human brain gene expression profiles in tauopathy.ResultsTauWT induced 1,514 and 213 differentially expressed transcripts and proteins, respectively. TauR406W had a substantially greater impact, causing changes in 5,494 transcripts and 697 proteins. There was a ~70% overlap between age- and Tau-induced changes and our analyses reveal pervasive bi-directional interactions. Strikingly, 42% of Tau-induced transcripts were discordant in the proteome, showing opposite direction of change. Tau-responsive gene expression networks strongly implicate innate immune activation, despite the absence of microglia in flies. Cross-species analyses pinpoint human brain gene perturbations specifically triggered by Tau pathology and/or aging, and further differentiate between disease amplifying and protective changes.ConclusionsOur results comprise a powerful, cross-species functional genomics resource for tauopathy, revealing Tau-mediated disruption of gene expression, including dynamic, age-dependent interactions between the brain transcriptome and proteome.

scholarly journals Largest GWAS (N=1,126,563) of Alzheimer’s Disease Implicates Microglia and Immune Cells

2020 ◽  
Author(s):  
Douglas P Wightman ◽  
Iris E Jansen ◽  
Jeanne E. Savage ◽  
Alexey A Shadrin ◽  
Shahram Bahrami ◽  
...  
Keyword(s):  
Gene Expression ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Genetic Variants ◽  
Late Onset ◽  
Gene Expression Pattern ◽  
Human Microglia ◽  
Age Related ◽  
Causal Genes ◽  
Meta Analyses

SummaryLate-onset Alzheimer’s disease is a prevalent age-related polygenic disease that accounts for 50-70% of dementia cases1. Late-onset Alzheimer’s disease is caused by a combination of many genetic variants with small effect sizes and environmental influences. Currently, only a fraction of the genetic variants underlying Alzheimer’s disease have been identified2,3. Here we show that increased sample sizes allowed for identification of seven novel genetic loci contributing to Alzheimer’s disease. We highlighted eight potentially causal genes where gene expression changes are likely to explain the association. Human microglia were found as the only cell type where the gene expression pattern was significantly associated with the Alzheimer’s disease association signal. Gene set analysis identified four independent pathways for associated variants to influence disease pathology. Our results support the importance of microglia, amyloid and tau aggregation, and immune response in Alzheimer’s disease. We anticipate that through collaboration the results from this study can be included in larger meta-analyses of Alzheimer’s disease to identify further genetic variants which contribute to Alzheimer’s pathology. Furthermore, the increased understanding of the mechanisms that mediate the effect of genetic variants on disease progression will help identify potential pathways and gene-sets as targets for drug development.

scholarly journals Insulin Signaling-independent Activation of DAF-16 Shapes the Transcriptome during Normal Aging

2018 ◽  
Author(s):  
Shang-Tong Li ◽  
Han-Qing Zhao ◽  
Pan Zhang ◽  
Chung-Yi Liang ◽  
Yan-Ping Zhang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Insulin Signaling ◽  
Aging Process ◽  
Normal Aging ◽  
Regulatory Mechanisms ◽  
Regulation Of Transcription ◽  
Wild Type ◽  
Age Dependent ◽  
Expression Program

SummaryThe roles and regulatory mechanisms of transriptome changes during aging are unclear. It has been proposed that the transcriptome suffers decay during aging owing to age-associated down-regulation of transcription factors. In this study, we characterized the role of a transcription factor DAF-16, which is a highly conserved lifespan regulator, in the normal aging process of Caenorhabditis elegans. We found that DAF-16 translocates into the nucleus in aged wild-type worms and activates the expression of hundreds of genes in response to age-associated cellular stress. Most of the age-dependent DAF-16 targets are different from the canonical DAF-16 targets downstream of insulin signaling, indicating that activation of DAF-16 during aging is not due to reduced insulin signaling from DAF-2. Further analysis showed that it is due to the loss of proteostasis during aging, at least in part. We also found that without daf-16, dramatic gene expression changes occur as early as on adult day 2, indicating that DAF-16 acts to stabilize the transcriptome during normal aging. Our results thus reveal that normal aging is not simply a process in which the gene expression program descends into chaos due to loss of regulatory activities; rather, there is active transcriptional regulation that fights aging.

Sign in / Sign up

Export Citation Format

Share Document