Long-term caffeine treatment of Alzheimer mouse models ameliorates behavioural deficits and neuron loss and promotes cellular and molecular markers of neurogenesis
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE183323 | GEO | 2021/12/13
REPOSITORIES: GEO
Similar Datasets
Project description:Alzheimer's disease (AD) is a devastating neurodegenerative disorder characterized by a progressive cognitive decline. Epidemiological studies have suggested a protective role of caffeine consumption against age-related cognitive impairments and the risk of developing AD. Effects of caffeine have been particularly ascribed to its ability to block adenosine A2A receptors (A2ARs). Early pathological upregulation of these receptors by neurons is thought to be involved in the development of synaptic and memory deficits in AD but this remains ill-defined. To tackle this question, we employed a novel transgenic mouse model allowing to promote a neuronal upregulation of A2AR in the hippocampus of APP/PS1 mice, developing AD-like amyloidogenesis. This new model was used to determine the impact of an early upregulation of A2AR on the progression of neuropathological lesions, associated behavior and underlying mechanisms in APP/PS1 mice. Our findings revealed that the early upregulation of A2AR in the presence of an ongoing amyloid pathology exacerbates memory impairments of APP/PS1 mice. These behavioral changes were not linked to major change in the development of amyloid pathology but rather associate with an increased p-tau at neuritic plaques. Moreover, proteomic and transcriptomic analysis coupled to quantitative immunofluorescence studies indicated that neuronal impairment of the receptor promoted both neuronal- and non-neuronal autonomous alterations i.e. loss of excitatory synapses and neuroinflammatory response, respectively, both presumably accounting for the detrimental effect on memory. Overall, our results provide compelling evidence that neuronal A2AR dysfunction as seen in the brain of patients contributes to AD pathogenesis, favoring synaptic deficits promoted by both amyloid (this study) and tau lesions (our previous study). In addition to provide new insights into the complex pathophysiology of AD, the present findings underscore the potential of A2AR as a relevant therapeutic target for mitigating early synaptic loss in this neurodegenerative disorder.
2023-11-30 | GSE248245 | GEO
Project description:Alzheimer's disease (AD) was attributed to alterations in multiple epigenetic systems including DNA methylation and demethylation patterns. DNA 5-hydroxymethylcytosin (5hmC), an epigenetic hallmark, plays importantly regulatory role in many biological processes. However, the 5hmC-mediated epigenetic underpinnings of AD neurodegeneration remain poorly understood. Here we report that selective loss of 5hmC is substantially presented in human AD and 3xTg-AD mouse neocortical and hippocampal neurons. Quantitative genome-wide analysis of hMeDIP-seq reveals that neuron-specific shift in decreased 5hmC enrichment in regions of promoter, intergenic and gene body of mRNA and lncRNA genes was found in3xTg-AD mice. We further identified that TET3, an enzyme that converts 5-methylcytosine (5mC) to 5hmC, responded to Beta amyloid neuronal toxicity and was mainly responsible for loss of 5hmC in AD brain. Overexpression of human TET3 catalytic domain (hTET3CD) significantly improves the neuroinflammation, neuropathological progression and cognitive deficits in 3xTg-AD mice. These findings implicate as a potential hallmark, TET3-mediated 5hmC epigenetic dysregulation is involved in driving AD neurodegeneration.
2019-02-19 | GSE126713 | GEO
Project description:Thiazolidinediones (TZDs) are agonists at peroxisome proliferator-activated gamma-type (PPAR-y) receptors and are used clinically for the treatment of type 2 diabetes where they have been shown to reestablish insulin sensitivity, improve lipids profile, and reduce inflammation. Recent work also suggests that TZDs may be beneficial in Alzheimer's disease (AD), ameliorating cognitive decline early in the disease process. However, there have been only a few studies identifying mechanisms through which cognitive benefits may be exerted. Starting at 10 months of age, the triple transgenic mouse model of AD (3xTg-AD) with accelerated amyloid-B (AB) deposition and tau pathology was treated with the TZD pioglitazone (PIO- Actos) at 18 mg/Kg body weight/day. After four months, PIO-treated animals showed multiple beneficial effects, including improved learning on the active avoidance task, reduced serum cholesterol, decreased hippocampal AB deposits, and enhanced short- and long-term plasticity. Baseline electrophysiological membrane properties and blood glucose levels were unchanged by PIO treatment. Gene microarray analyses of hippocampal tissue identified predicted transcriptional responses following TZD treatment as well as potentially novel targets of TZDs, including facilitation of estrogenic processes, and decreases in glutamatergic and ketone metabolic/ cholesterol dependent processes. Taken together, these results confirm prior animal studies showing that TZDs can ameliorate cognitive deficits associated with AD-related pathology, but also extend these findings by pointing to novel molecular targets in the brain. Keywords : Hippocampus; LTP; Microarray analysis; Avoidance learning; Aging; PPAR; Synaptic hyperpolarization; T2DM We used the 3xTg-AD mouse model of Alzheimer's disease and monitored the effects of pioglitazone (PIO-Actos a TZD) on behavioral, electrophysiological, and molecular variables. Emphasis was placed on identifying hippocampal PIO-sensitive genes that were also associated with learning and memory processes. Starting at 10 months of age, female mice were treated for approximately 14 weeks with either a control diet or a PIO-containing diet. PIO was incorporated into the diet to yield a final dose of approximately 18 mg/kg body weight/day.
2012-04-12 | E-GEOD-32536 | biostudies-arrayexpress
Project description:Alzheimer's disease (AD) patients exhibit neuropsychiatric symptoms that extend beyond classical cognitive deficits, suggesting involvement of subcortical areas. Here, we investigated the role of midbrain dopamine (DA) neurons in AD using the amyloid + tau-driven 3xTg-AD mouse model. We found deficits in reward-based operant learning in AD mice, suggesting possible VTA DA neuron dysregulation. Physiological assessment revealed hyperexcitability and disrupted firing in DA neurons caused by reduced activity of small-conductance calcium-activated potassium (SK) channels. RNA sequencing from contents of single patch-clamped DA neurons (Patch-seq) identified up-regulation of the SK channel modulator casein kinase 2 (CK2). Pharmacological inhibition of CK2 restored SK channel activity and normal firing patterns in 3xTg-AD mice. These findings shed light on a complex interplay between neuropsychiatric symptoms and subcortical circuits in AD, paving the way for novel treatment strategies.
2024-09-14 | GSE273040 | GEO
Project description:Early-life adversity (ELA) is associated with lifelong memory deficits, yet the responsible mechanisms remain unclear. We imposed ELA by rearing rat pups in simulated poverty, assessed hippocampal memory, and probed changes in gene expression, their transcriptional regulation and the consequent changes in hippocampal neuronal structure. ELA rats had poor hippocampal memory and stunted hippocampal pyramidal neurons, associated with ~140 differentially expressed genes. Upstream regulators of the altered genes included glucocorticoid receptor and, unexpectedly, the transcription factor neuron-restrictive silencer factor (NRSF/REST). NRSF contributed critically to the memory deficits because blocking its function transiently following ELA rescued spatial memory and restored the dendritic arborization of hippocampal pyramidal neurons in ELA rats. Blocking NRSF function in vitro augmented dendritic complexity of developing hippocampal neurons, suggesting that NRSF represses genes involved in neuronal maturation. These findings establish important, surprising contributions of NRSF to ELA-induced transcriptional programming that disrupts hippocampal maturation and memory function.
2020-12-15 | GSE161498 | GEO
Project description:The pathophysiology of Alzheimer’s disease (AD) is multifactorial with characteristic extracellular accumulation of amyloid-beta (Aβ) and intraneuronal aggregation of hyperphosphorylated tau in the brain. Development of disease-modifying treatment for AD has been challenging. Recent studies suggest that deleterious alterations in neurovascular cells happens in parallel with Aβ accumulation, inducing tau pathology and necroptosis. Therefore, therapies targeting cellular Aβ and tau pathologies may provide a more effective strategy of disease intervention. Tetramethylpyrazine nitrone (TBN) is a nitrone derivative of tetramethylpyrazine, an active ingredient from Ligusticum wallichii Franchat (Chuanxiong). We previously showed that TBN is a potent scavenger of free radicals with multi-targeted neuroprotective effects in rat and monkey models of ischemic stroke. The present study aimed to investigate the anti-AD properties of TBN. We employed AD-related cellular model (N2a/APPswe) and transgenic mouse model (3×Tg-AD mouse) for mechanistic and behavioral studies. Our results showed that TBN markedly improved cognitive functions and reduced Aβ and hyperphosphorylated tau levels in mouse model. Further investigation of the underlying mechanisms revealed that TBN promoted non amyloidogenic processing pathway of amyloid precursor protein (APP) in N2a/APPswe in vitro. Moreover, TBN preserved synapses from dendritic spine loss and upregulated synaptic protein expressions in 3×Tg-AD mice. Proteomic analysis of 3×Tg-AD mouse hippocampal and cortical tissues showed that TBN induced neuroprotective effects through modulating mitophagy, MAPK and mTOR pathways. In particular, TBN significantly upregulated PINK1, a key protein for mitochondrial homeostasis, implicating PINK1 as a potential therapeutic target for AD. In summary, TBN improved cognitive functions in AD-related mouse model, inhibited Aβ production and tau hyperphosphorylation, and rescued synaptic loss and neuronal damage. Multiple mechanisms underlie the anti-AD effects of TBN including the modulation of APP processing, mTOR signaling and PINK1-related mitophagy.
2023-05-10 | PXD039514 | Pride
Project description:It was recently revealed that gut microbiota promote amyloid-beta (Aβ) burden in mouse models of Alzheimer’s disease (AD). However, the underlying mechanisms when using either germ-free (GF) housing conditions or treatments with antibiotics (ABX) remained unknown. In this study, we show that GF and ABX-treated 5x familial AD (5xFAD) mice developed attenuated hippocampal Aβ pathology and associated neuronal loss, and thereby delayed disease-related memory deficits. While Ab production remained unaffected in both GF and ABX-treated 5xFAD mice, we noticed in GF 5xFAD mice enhanced microglial Aβ uptake at early stages of the disease compared to ABX-treated 5xFAD mice. Furthermore, RNA-sequencing of hippocampal microglia from SPF, GF and ABX-treated 5xFAD mice revealed distinct microbiota-dependent gene expression profiles associated with phagocytosis and altered microglial activation states. Taken together, we observed that constitutive or induced microbiota modulation in 5xFAD mice differentially controls microglial Aβ clearance mechanisms preventing neurodegeneration and cognitive deficits.
2020-07-15 | GSE154428 | GEO
Project description:Maternal alcohol consumption during pregnancy results in a spectrum of lifelong behavioral and cognitive deficits collectively known as Fetal Alcohol Spectrum Disorders (FASD). FASD is a major health burden in most societies, there is no cure, and the molecular mechanism involved in its development is poorly understood. Human neurodevelopment is a continuum that extends over two decades after birth, with the potential to influence outcomes both prenatally and postnatally. Here, we experimentally investigate if positive postnatal environment enrichment ameliorates behavioral deficits caused by ethanol exposure. Furthermore, we assessed if this modulation is associated with alterations in hippocampal gene expression. To accomplish this, we used a binge model of ethanol exposure followed by environmental enrichment in C57BL/6 mice to generate four groups of animals: (1) control mice raised in standard conditions, (2) mice raised in enriched environments, (3) ethanol-exposed mice raised in standard conditions, and (4) ethanol-exposed mice raised in enriched environments. The environmental enrichment includes larger home cages with more individuals for social interaction, regular exposure to novel items, and access to running wheels. Ethanol exposure results in anxiety-like behavior (light-dark box) as well as learning and memory deficits (Barnes maze) that are at least partially ameliorated by enrichment. Environmental enrichment also improves performance for individuals not exposed to ethanol. Ethanol exposure induces changes in adult hippocampal gene expression (RNA-Seq). Some of the changes in adult hippocampal gene expression following ethanol exposure are reversed by environmental enrichment. The results offer a potential mechanism of behavioral deficits caused by ethanol exposure, including the potential for amelioration after an FASD diagnosis.
2021-09-24 | GSE184615 | GEO
Project description:Post-mortem investigations indicate that the locus coeruleus (LC) is the initial site of hyperphosphorylated pretangle tau, a precursor to neurofibrillary tangles (NFTs) found in Alzheimer's disease (AD). The presence of pretangle tau and NFTs in the LC correlates with AD progression. LC neuron integrity and quantity are linked to cognitive states, with degeneration associated with AD. However, the mechanisms of pretangle tau-induced LC degeneration are unclear. This study examined the transcriptomic and mitochondrial profiles of LC noradrenergic neurons after transduction with pseudophosphorylated human tau. Tau hyperphosphorylation increased the somatic expression of the L-type calcium channel (LTCC), impaired mitochondria health, and led to deficits in spatial and olfactory learning. Sex-dependent alterations in gene expression were observed in rats transduced with pretangle tau. Chronic LTCC blockade prevented behavioral deficits and altered mitochondrial mRNA expression, suggesting a potential link between LTCC hyperactivity and mitochondrial dysfunction. Our research provides insights into the consequences of tau pathology in the originating structure of AD.
2024-11-16 | GSE272794 | GEO
Project description:The decline of cognitive function is a feature of normal human aging and is exacerbated in Alzheimer’s disease (AD). DNA repair declines in brain cells during normal aging and even more so in AD. Here we show that experimental reduction in levels of the base excision repair enzyme, DNA polymerase β (Polb) renders neurons vulnerable to age-related dysfunction and degeneration in a mouse model of AD. Whereas 3xTgAD mice exhibit age-related extracellular amyloid b-peptide (Ab) accumulation and cognitive deficits, but no neuronal death, 3xTg/Polb+/- mice accumulates intracellular Ab and neurons die in the hippocampus and cerebral cortex. The DNA repair-deficient 3xTgAD mice exhibited increased DNA strand breaks and apoptotic caspase activation with loss of hippocampal volume, and impaired synaptic plasticity and memory retention. Molecular profiling revealed remarkable similarities in gene expression alterations in brain cells of AD patients and 3xTgAD/Polb+/- mice including multiple abnormalities suggestive of impaired cellular bioenergetics. Our findings demonstrate that a modest decrement in oxidative DNA damage processing is sufficient to render neurons vulnerable to AD-related pathogenic molecular and cellular alterations that result in the dysfunction and death of neurons, and associated cognitive deficits.
2015-01-05 | GSE60911 | GEO