Neuronal synchronization at gamma frequency (30-100 Hz: γ) is impaired in early-stage Alzheimer's disease (AD) patients and AD models. Oligomeric Aβ caused a concentration-dependent reduction of γ-oscillation strength and regularity while increasing its frequency. The mTOR1 inhibitor rapamycin prevented the Aβ-induced suppression of γ-oscillations, whereas the mTOR activator leucine mimicked the Aβ-induced suppression.
View Article and Find Full Text PDFEsophageal squamous cell carcinoma (ESCC) is an invasive malignant tumor with a high incidence rate and mortality. It is imperative to study its tumorigenesis and development for better treatment. CircRNA has been proven to play an important role in various cancers.
View Article and Find Full Text PDFBackground: Autophagy dysfunction plays a crucial role in tau accumulation and neurodegeneration in Alzheimer's disease (AD). This study aimed to investigate whether and how the accumulating tau may in turn affect autophagy.
Methods: The primary hippocampal neurons, N2a and HEK293T cells with tau overexpression were respectively starved and treated with vinblastine to study the effects of tau on the initiating steps of autophagy, which was analysed by Student's two-tailed t-test.
Background: Increased tau acetylation at K174, K274, K280, and K281 has been observed in the brains of Alzheimer's disease (AD) patients or in transgenic mice, but the role of acetylation in tau propagation is elusive.
Objective: To study the effect of tau acetylation in entorhinal cortex on tau transmission and learning and memory.
Methods: Stereotactic brain injection, behavioral test, electrophysiological recording, immunohistochemistry, and immunofluorescence were used.
J Alzheimers Dis
September 2019
Extracellular accumulation of amyloid-β (Aβ) forming senile plaques is one of the hallmark pathologies in Alzheimer's disease (AD), while the mechanisms underlying the neuronal toxic effect of Aβ are not fully understood. Here, we found that intracerebroventricular infusion of the aged Aβ42 in mice only induces memory deficit at 24 h but not at 7 days. Interestingly, a remarkably increased CREB (cAMP response element-binding protein) Ser133-phosphorylation (pS133-CREB) with microglial activation was detected at 24 h but not at 7 days after Aβ infusion.
View Article and Find Full Text PDFThe cholinergic impairment is an early marker in Alzheimer's disease (AD), while the mechanisms are not fully understood. We investigated here the effects of glycogen synthase kinse-3 (GSK-3) activation on the cholinergic homoeostasis in nucleus basalis of Meynert (NBM) and frontal cortex, the cholinergic enriched regions. We activated GSK-3 by lateral ventricular infusion of wortmannin (WT) and GF-109203X (GFX), the inhibitors of phosphoinositol-3 kinase (PI3-K) and protein kinase C (PKC), respectively, and significantly decreased the acetylcholine (ACh) level via inhibiting choline acetyl transferase (ChAT) rather than regulating acetylcholinesterase (AChE).
View Article and Find Full Text PDFOlfactory dysfunction is recognized as a potential risk factor for Alzheimer's disease (AD). We have reported previously that olfactory deprivation by olfactory bulbectomy (OBX) induced Alzheimer's-like pathological changes and behavioral abnormalities. However, the acute OBX model undergoes surgical-induced brain parenchyma loss and unexpected massive hemorrhage so that it cannot fully mimic the progressive olfactory loss and neurodegeneration in AD.
View Article and Find Full Text PDFTau is a microtubule-associated protein implicated in neurodegenerative tauopathies. Six tau isoforms are generated from a single gene through alternative splicing of exons 2, 3 and 10 in human brain. Differential expression of tau isoforms has been detected in different brain areas, during neurodevelopment and in neurodegenerative disorders.
View Article and Find Full Text PDFAlzheimer's disease (AD) is characterized by profound synapse loss and impairments of learning and memory. Magnesium affects many biochemical mechanisms that are vital for neuronal properties and synaptic plasticity. Recent studies have demonstrated that the serum and brain magnesium levels are decreased in AD patients; however, the exact role of magnesium in AD pathogenesis remains unclear.
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