Aging-linked deterioration of RNA metabolism destabilizes the stress response of neurons [RNA-seq]
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE276986 | GEO | 2025/02/18
REPOSITORIES: GEO
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Project description:Aging is one of the most prominent risk factors for neurodegeneration, yet the molecular mechanisms underlying the deterioration of old neurons are mostly unknown. To efficiently study neurodegeneration in the context of aging, we transdifferentiated primary human fibroblasts from aged healthy donors directly into neurons, which retained their aging markers. Here we show that aged neurons are broadly depleted of RNA-binding proteins, especially spliceosome components. Intriguingly, splicing proteins – like the dementia and ALS-associated protein TDP-43 – mislocalize to the cytoplasm in aged neurons, which leads to widespread alternative splicing. Cytoplasmic spliceosome components typically are recruited to stress granules, but aged neurons suffer from chronic stress that prevents this sequestration. We link chronic stress to the malfunctioning ubiquitylation machinery, poor HSP90α chaperone activity, and the failure to respond to new stress events. Together our data demonstrates that aging-linked deterioration of RNA biology is a key driver of poor resiliency in aged neurons.
2025-02-18 | GSE277082 | GEO
Project description:Aging is one of the most prominent risk factors for neurodegeneration, yet the molecular mechanisms underlying the deterioration of old neurons are mostly unknown. To efficiently study neurodegeneration in the context of aging, we transdifferentiated primary human fibroblasts from aged healthy donors directly into neurons, which retained their aging markers. Here we show that aged neurons are broadly depleted of RNA-binding proteins, especially spliceosome components. Intriguingly, splicing proteins – like the dementia and ALS-associated protein TDP-43 – mislocalize to the cytoplasm in aged neurons, which leads to widespread alternative splicing. Cytoplasmic spliceosome components typically are recruited to stress granules, but aged neurons suffer from chronic stress that prevents this sequestration. We link chronic stress to the malfunctioning ubiquitylation machinery, poor HSP90α chaperone activity, and the failure to respond to new stress events. Together our data demonstrates that aging-linked deterioration of RNA biology is a key driver of poor resiliency in aged neurons.
2025-02-18 | GSE276985 | GEO
Project description:Astrocytes are key cells in brain aging, helping neurons to undertake healthy aging or otherwise letting them enter into a spiral of neurodegeneration. We aimed to characterize astrocytes cultured from senescence-accelerated prone 8 (SAMP8) mice, a mouse model of brain pathological aging, along with the effects of caloric restriction, the most effective rejuvenating treatment known so far. Analysis of the transcriptomic profiles of SAMP8 astrocytes cultured in control conditions and treated with caloric restriction serum was performed using mRNA microarrays. A decrease in mitochondrial and ribosome mRNA, which was restored by caloric restriction, confirmed the age-related profile of SAMP8 astrocytes and the benefits of caloric restriction. An amelioration of antioxidant and neurodegeneration-related path- ways confirmed the brain benefits of caloric restriction. Studies of oxidative stress and mitochondrial function demonstrated a reduction of oxidative damage and partial improvement of mito- chondria after caloric restriction. In summary, caloric restriction showed a significant tendency to normalize pathologically aged astrocytes through the activation of pathways that are protective against the age-related deterioration of brain physiology. Key words: astrocytes; caloric restriction; mitochondria; oxidative stress; RNA microarrays; SAMP8.
2015-06-23 | GSE60388 | GEO
Project description:Astrocytes are key cells in brain aging, helping neurons to undertake healthy aging or otherwise letting them enter into a spiral of neurodegeneration. We aimed to characterize astrocytes cultured from senescence-accelerated prone 8 (SAMP8) mice, a mouse model of brain pathological aging, along with the effects of caloric restriction, the most effective rejuvenating treatment known so far. Analysis of the transcriptomic profiles of SAMP8 astrocytes cultured in control conditions and treated with caloric restriction serum was performed using mRNA microarrays. A decrease in mitochondrial and ribosome mRNA, which was restored by caloric restriction, confirmed the age-related profile of SAMP8 astrocytes and the benefits of caloric restriction. An amelioration of antioxidant and neurodegeneration-related path- ways confirmed the brain benefits of caloric restriction. Studies of oxidative stress and mitochondrial function demonstrated a reduction of oxidative damage and partial improvement of mito- chondria after caloric restriction. In summary, caloric restriction showed a significant tendency to normalize pathologically aged astrocytes through the activation of pathways that are protective against the age-related deterioration of brain physiology. Key words: astrocytes; caloric restriction; mitochondria; oxidative stress; RNA microarrays; SAMP8. Primary cultures enriched in astrocytes were obtained from cerebral cortical tissue from 2-day-old SAMP8 and SAMR1 mice. Astrocyte cultures were established and experiments were routinely carried out after 21 days in culture. Established astrocyte cultures of both SAMR1 and SAMP8 consisted of 85-90% astrocytes, 10-15% microglia and 0.1-1% oligodendroglia. Sera from rats subjected to ad libitum (AL) diet and to CR were obtained as described for the establishment of the CR in vitro model (de Cabo et al., 2003). Serum was heat inactivated at 56°C prior to use in astrocyte culture experiments. Treatment in vitro was performed by adding 10% volume CR or AL serum onto the astrocyte culture medium for 48 h, the cells were harvested and RNA was extracted for the microarray studies. Three biological replicates for each condition were done and RNA was extracted for the microarray studies. Please note that SAM models were developed from AKR/J by Kyoto University. Five litters with severe senescence were selected to further propagate and examine these characteristics. Litters that showed normal aging were selected as a senescence-resistant series (R-series). The genetic background of the SAM mice became suspect after the pathological findings were different from the AKR/J mouse. Each SAM model is genetically different. Each SAM colony was acquired by Harlan by Takeda Chemical Ltd. in 2002. And here is the link to the company site. http://www.harlan.com/products_and_services/research_models_and_services/research_models/sam_inbred_mice/samp8tahsd.hl
2015-06-23 | E-GEOD-60388 | biostudies-arrayexpress
Project description:Deficits in chemosensory processing are associated with healthy aging, as well as numerous neurodegenerative disorders, including Alzheimer’s Disease (AD). In many cases, chemosensory deficits are harbingers of neurodegenerative disease, and understanding the mechanistic basis for these changes may provide insight into the fundamental dysfunction associated with aging and neurodegeneration. The fruit fly, Drosophila melanogaster, is a powerful model for studying chemosensation, aging, and aging-related pathologies, yet the effects of aging and neurodegeneration on chemosensation remain largely unexplored in this model, particularly with respect to taste. To determine whether the effects of aging on taste are conserved in flies, we compared the response of flies to different appetitive tastants. Aging impaired response to sugars, but not medium-chain fatty acids that are sensed by a shared population of neurons, revealing modality-specific deficits in taste. Selective expression of the human amyloid beta (Ab) 1-42 peptide bearing the Arctic mutation (E693E) associated with early onset AD in the neurons that sense sugars and fatty acids phenocopies the effects of aging, suggesting that the age-related decline in response is localized to gustatory neurons. Functional imaging of gustatory axon terminals revealed reduced response to sugar, but not fatty acids. Axonal innervation of the fly taste center was largely intact in aged flies, suggesting that reduced sucrose response does not derive from neurodegeneration. Conversely, expression of the amyloid peptide in sweet-sensing taste neurons resulted in reduced innervation of the primary fly taste center. A comparison of transcript expression within the sugar-sensing taste neurons revealed age-related changes in 66 genes, including a reduction in odorant-binding protein class genes that are also expressed in taste sensilla. Together, these findings suggest that deficits in taste detection may result from signaling pathway-specific changes, while different mechanisms underly taste deficits in aged and AD model flies. Overall, this work provides a model to examine cellular deficits in neural function associated with aging and AD.
2024-10-13 | GSE273715 | GEO
Project description:A detailed knowledge of the mechanisms underlying brain aging is fundamental to understand its functional decline and the baseline upon which brain pathologies superimpose. Endogenous protective mechanisms must contribute to the adaptability and plasticity still present in the healthy aged brain. Apolipoprotein D (ApoD) is one of the few genes with a consistent and evolutionarily conserved up-regulation in the aged brain. ApoD protecting roles upon stress or injury are well known, but a study of the effects of ApoD expression in the normal aging process is still missing. Using an ApoD-knockout mouse we analyze the effects of ApoD on factors contributing to the functional maintenance of the aged brain. We focused our cellular and molecular analyses in cortex and hippocampus at an age representing the onset of senescence where mortality risks are below 25%, avoiding bias towards long-lived animals. Lack of ApoD causes a prematurely aged brain without altering lifespan. Age-dependent hyperkinesia and memory deficits are accompanied by differential molecular effects in cortex and hippocampus. Transcriptome analyses reveal distinct effects of ApoD loss on the molecular age-dependent patterns of cortex and hippocampus, with different cell-type contributions to age-regulated gene expression. Markers of glial reactivity, proteostasis, and oxidative and inflammatory damage reveal early signs of aging and enhanced brain deterioration in the ApoD-knockout brain. The lack of ApoD results in an age-enhanced significant reduction in neuronal calcium-dependent functionality markers and signs of early reduction of neuronal numbers in the cortex, thus impinging upon parameters clearly differentiating neurodegenerative conditions from healthy brain aging. Our data support the hypothesis that the physiological increased brain expression of ApoD represents a homeostatic anti-aging mechanism. The brain cortex and hippocampus of young and aged mice of wild-type and ApoD-KO genotypes were used for RNA extraction and hybridization on Affymetrix microarrays. We aim at identifying distinct effects of ApoD loss on the molecular age-dependent patterns of cortex and hippocampus.
2015-04-23 | E-GEOD-68169 | biostudies-arrayexpress
Project description:Infantile neuronal ceroid lipofuscinosis (aka infantile Batten disease) is a severe neurodegenerative disorder of early childhood characterized by cortical atrophy, blindness and seizures, leading to premature death in the first decade. The disorder is caused by deficiency in a soluble lysosomal enzyme, palmitoyl protein thioesterase-1 (PPT1). PPT1 knockout mice faithfully reproduce the features of the human disease, with motor deterioration, blindness, seizures, and death before 10 months of age. The progression of events leading from enzyme deficiency to organ failure is poorly defined. The neuronal ceroid lipofuscinoses are of particular interest because of the similarities between the accumulated material and lipofuscin that is associated with normal aging. We will determine changes in gene expression that occur during the course of neurodegeneration in PPT1 knockout as compared to control mice. Gene expression profiling of brain tissue from PPT1 knockout mice as compared to normal controls will provide insights into the mechanism of neurodegeneration. Comparison of this profile with gene expression profiles associated with normal aging may provide insights into the contribution of lipofuscin to aging and neurodegeneration. PPT1 knockout mice on a C57BL/6 background will be sacrificed under CO2 and whole brains removed and frozen under liquid nitrogen. Three mice will be used for each time point. Data points will be collected at 3 months, 5 months and 8 months of age. Normal age- and sex-matched C57BL/6 mice will be used as controls.
2008-06-15 | E-GEOD-6678 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE24992: Drosophila brain microRNA expression with age: miRNA profiling GSE25007: Drosophila brain gene expression with age: mRNA profiling GSE25008: Drosophila brain gene expression between wildtype and miR-34 null flies Refer to individual Series. Aging is the most prominent risk factor for human neurodegenerative disease, but underlying mechanisms that connect two processes are less well characterized. With age, the brain undergoes functional decline and perhaps degeneration. Such decline may not just contribute to normal aging, but also enhance susceptibility to and progression of age-related neurodegenerative diseases. Therefore, defining intrinsic factors and pathways that underline the normal integrity of the adult nervous system may lead to insights that potentially link aging and neurodegeneration. Here, we report a highly conserved microRNA (miRNA), miR-34, as a modulator of aging and neurodegeneration. Using Drosophila, we show that fly miR-34 expression is brain-enriched and strikingly upregulated with age. Functional studies reveal that, whereas animals without miR-34 are normal as young adults, upon aging, they gradually show late-onset deficits characteristic of accelerated brain aging; these include a transcriptional signature of aged animals, coupled with rapid functional decline, loss of brain integrity, followed by a catastrophic decline in adult viability. Moreover, upregulation of miR-34 protects against neurodegeneration induced by pathogenic human polyglutamine (polyQ) disease protein. We next reveal a dramatic effect of miR-34 to silence the Eip74EF gene of steroid hormone pathways in the adult, which is crucial to maintain the normal aging. Collectively, these data define a miR-34-mediated mechanism that specifically affects long-term integrity of the adult nervous system. miR-34 function in Drosophila may thus present a link that functionally connects aging and neurodegeneration. Our studies implicate essential roles of miRNA- dependent pathways in maintenance of the adult brain, disease pathogenesis and healthy aging.
2011-12-23 | E-GEOD-25009 | biostudies-arrayexpress
Project description:Aging is a physiological process occurring in all living organisms. It is characterized by a pro-gressive deterioration of the physiological and cognitive functions of the organism, accompanied by a gradual impairment of mechanisms involved in the regulation of tissue and organ homeo-stasis, thus exacerbating the risk of developing pathologies, including cancer and neurodegener-ative disorders. In the present work, we sought to investigate the influence of aging upon the expression protein profile in the brain cortex of grazing cattle, through LC-MS/MS-based differ-ential proteomics and bioinformatic analysis approach. We found a significant downregulation of proteins involved in synaptic plasticity, myelination, dendritic process, and oxidative stress in the cortex of aged bovine when compared to the adult samples. In conclusion, our data pave the way for a better understanding of molecular mechanisms underlying brain aging in cattle.
2023-11-27 | PXD044108 | Pride
Project description:A major goal of healthy aging is to prevent declining resilience and increasing frailty, which are associated with many chronic diseases and deterioration of stress response. We have successfully used loss-or-gain model of stress survival to quantify organismal resilience. As a proof of concept, this is demonstrated in C. elegans exposed to increasing oxidative stress induced by exogenous paraquat and with proteotoxic stress caused by endogenous polyQ and Aβ aggregation, respectively. Based on this, we reveal that abalone peptide AbaPep#07 (SETYELRK) not only promotes survival resilience against paraquat-induced oxidative stress but also confers protection against polyQ- or Aβ-mediated behavioral dysfunction in C. elegans, indicating its capacity against stress and neurodegeneration. Importantly, we further show that the peptide increases physical fitness of aged C. elegans and extends life span without compromise of growth and reproduction, demonstrating its cost-free prolongevity activity. Moreover, we reveal that the peptide induces differential expression of a number of genes, including innate immune, lipid metabolism and metabolic detoxification genes, which are associated with the SKN-1/Nrf transcription factor. Collectively, our findings demonstrate that the novel abalone cryptide AbaPep#07 increases stress survival resilience and cost-free longevity via SKN-1/Nrf-governed transcriptional reprogramming and provide an insight into the neuroprotective and health-promoting potential of cryptides as proteostasis regulators.
2023-11-06 | GSE246759 | GEO