Normally post-mitotic neurons that aberrantly re-enter the cell cycle without dividing account for a substantial fraction of die in Alzheimer's disease (AD). We now report this ectopic re-entry (CCR) requires soluble amyloid-β (Aβ) and tau, respective building blocks insoluble plaques tangles accumulate AD brain. Exposure cultured wild type (WT) to Aβ oligomers caused CCR activation non-receptor tyrosine kinase, fyn, cAMP-regulated protein kinase A calcium-calmodulin II, which respectively...

Abstract A major obstacle to presymptomatic diagnosis and disease‐modifying therapy for Alzheimer's disease (AD) is inadequate understanding of molecular mechanisms AD pathogenesis. For example, impaired brain insulin signaling an hallmark, but whether how it might contribute the synaptic dysfunction neuron death that underlie memory cognitive impairment has been mysterious. Neuron in often caused by cell cycle reentry (CCR) mediated amyloid‐β oligomers (AβOs) tau, precursors plaques...

The voltage- and Ca 2+ -activated K + (K V,Ca ) channel is expressed in a variety of polarized epithelial cells seemingly displaying tissue-dependent apical-to-basolateral regionalization, as revealed by electrophysiology. Using domain-specific biotinylation immunofluorescence we show that the human α-subunit (human Slowpoke channel, h Slo predominantly found apical plasma membrane domain permanently transfected Madin-Darby canine kidney cells. Both wild-type mutant protein lacking its only...

Galectins have been implicated in T cell homeostasis playing complementary pro-apoptotic roles. Here we show that galectin-8 (Gal-8) is a potent agent Jurkat cells inducing complex phospholipase D/phosphatidic acid signaling pathway has not reported for any galectin before. Gal-8 increases phosphatidic signaling, which enhances the activity of both ERK1/2 and type 4 phosphodiesterases (PDE4), with subsequent decrease basal protein kinase A activity. Strikingly, rolipram inhibition PDE4...

Activation of Rac1 and related Rho GTPases involves dissociation from RhoGDI translocation to membranes, where they bind effectors. Previous studies suggested that Rac membrane binding requires co-localizes with cholesterol-rich, liquid-ordered (lo) domains, called lipid rafts. Here, we develop a fluorescence resonance energy transfer (FRET) assay robustly detects targeting in living cells. Surprisingly, FRET acceptor constructs targeted either raft or non-raft regions indicated was present...

Anchorage dependence of cell growth, which is mediated by multiple integrin-regulated signaling pathways, a key defense against cancer metastasis. Detachment cells from the extracellular matrix triggers caveolin-1–dependent internalization lipid raft components, mediates suppression Rho GTPases, Erk, and phosphatidylinositol 3-kinase in suspended cells. Elevation cyclic adenosine monophosphate (cAMP) following detachment also implicated termination growth Studies integrins rafts, however,...

Neuronal nuclei are normally smoothly surfaced. In Alzheimer's disease (AD) and other tauopathies, though, they often develop invaginations. We investigated mechanisms functional consequences of neuronal nuclear invagination in tauopathies.

Reduced brain energy metabolism, mammalian target of rapamycin (mTOR) dysregulation, and extracellular amyloid beta (Aβ) oligomer (xcAβO) buildup are some well-known Alzheimer's disease (AD) features; how they promote neurodegeneration is poorly understood. We previously reported that xcAβOs inhibit nutrient-induced mitochondrial activity (NiMA) in cultured neurons. now report NiMA disruption vivo.

Altered mitochondrial DNA (mtDNA) occurs in neurodegenerative disorders like Alzheimer's disease (AD); how mtDNA synthesis is linked to neurodegeneration poorly understood. We previously discovered Nutrient-induced Mitochondrial Activity (NiMA), an inter-organelle signaling pathway where nutrient-stimulated lysosomal mTORC1 activity regulates replication neurons by a mechanism sensitive amyloid-β oligomers (AβOs), primary factor AD pathogenesis (Norambuena et al., 2018). Using...

Endocytosis modulates EGFR function by compartmentalizing and attenuating or enhancing its ligand-induced signaling. Here we show that it can also control the cell surface versus intracellular distribution of empty/inactive EGFR. Our previous observation PKA inhibitors induce internalization prompted us to test phosphatidic acid (PA) generated phospholipase D (PLD) as an endogenous down-regulator activity, which activates rolipram-sensitive type 4 phosphodiesterases (PDE4) degrade cAMP. We...

Epidermal growth factor receptor ( EGFR ) exaggerated (oncogenic) function is currently targeted in cancer treatment with drugs that block ligand binding or tyrosine kinase activity. Because endocytic trafficking a crucial regulator of function, its pharmacological perturbation might provide new anti‐tumoral strategy. Inhibition phosphatidic acid PA phosphohydrolase PAP activity has been shown to trigger signaling towards type 4 phosphodiesterase PDE 4) activation and protein A inhibition,...

Individuals are at risk of exposure to acute ionizing radiation (IR) from a nuclear accident or terrorism, but we lack effective therapies mitigate the lethal IR effects. In current study, exploited an optimized, cell-based, high throughput screening assay interrogate small molecule library comprising 3437 known pharmacologically active compounds for mitigation against IR-induced apoptosis. Thirty-three significantly reduced apoptosis when administered 1 h after 4 Gy IR. Two-...

Extracellular nucleotides transmit signals into the cells through P2 family of cell surface receptors. These receptors are amply expressed in human blood vessels and participate vascular tone control; however, their signaling mechanisms remain unknown. Here we show that smooth muscle isolated chorionic arteries, activation P2Y2 receptor (P2Y2R) induces not only its partition membrane rafts but also rapid internalization. Cholesterol depletion with methyl-β-cyclodextrin reduced association...

The nucleotide P2Y₁ receptor (P2Y₁R) is expressed in both the endothelial and vascular smooth muscle cells; however, its plasma membrane microregionalization internalization human tissues remain unknown. We report on role of rafts P2Y₁R signaling by using sodium carbonate or OptiPrep sucrose density gradients, Western blot analysis, reduction tissue cholesterol content, vasomotor assays endothelium-denuded chorionic arteries. In extracts prepared either...

Abstract Introduction Reduced brain energy metabolism, mTOR dysregulation, and extracellular amyloid-β oligomer (xcAβO) buildup characterize AD; how they collectively promote neurodegeneration is poorly understood. We previously reported that xcAβOs inhibit N utrient-induced M itochondrial A ctivity (NiMA) in cultured neurons. now report NiMA disruption vivo . Methods Brain metabolism oxygen consumption were recorded APP SAA/+ mice using two-photon fluorescence lifetime imaging...

Alzheimer’s disease (AD) is defined by memory loss and cognitive impairment, along with the accumulation in brain of two types abnormal structures, extracellular amyloid plaques intraneuronal neurofibrillary tangles. Both tangles are composed predominantly poorly soluble filaments that respectively assemble from amyloid-β (Aβ) peptides neuron-specific, microtubule-associated protein, tau. It now widely acknowledged oligomers Aβ tau, building blocks tangles, principal drivers AD pathogenesis...

To assess the role of P2X1 receptors (P2X1R) in longitudinal and circular layers human vas deferens, ex vivo-isolated strips or rings were prepared from tissue biopsies to record isometric contractions. ascertain its membrane distribution, extracts analyzed by immunoblotting following sucrose gradient ultracentrifugation. ATP, alpha,beta-methylene electrical field stimulation elicited robust contractions layer but not which demonstrated inconsistent responses. Alpha,beta-methylene ATP...

The advances in the field of optics and laser technologies are helpful to visualize investigate metabolism live animals. Fluorescence lifetime imaging (FLIM) is a non-invasive optical technique measure fluorescence fluorophore towards its applications where intensity-based techniques do not provide sufficient accurate information discriminate auto-fluorescent species. In contrast conventional single photon excitation, two-photon excitation improves penetration depth with low scattering...

Alterations in NADH and NADPH metabolism are associated with aging, cancer, Alzheimer’s Disease. Using 2P-FLIM imaging of the mitochondrial NAD(P)H live human neurons PS19 mouse brains, we show that tau oligomers (TauO) upregulate de novo synthesis through NADK2. This process controls LRP1-mediated internalization TauO, setting a vicious cycle for further TauO internalization. Thus, NADK2-dependent key step toxicity.