scholarly journals Glucose deprivation increases tau phosphorylation via P 38 mitogen‐activated protein kinase

Aging Cell ◽  
2015 ◽  
Vol 14 (6) ◽  
pp. 1067-1074 ◽  
Author(s):  
Elisabetta Lauretti ◽  
Domenico Praticò
Keyword(s):  
Protein Kinase ◽  
Glucose Deprivation ◽  
Tau Phosphorylation ◽  
Mitogen Activated Protein Kinase ◽  
Mitogen Activated Protein

Isoflurane Preconditions Hippocampal Neurons against Oxygen–Glucose Deprivation

2005 ◽  
Vol 103 (3) ◽  
pp. 532-539 ◽  
Author(s):  
Philip E. Bickler ◽  
Xinhua Zhan ◽  
Christian S. Fahlman
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Kinase ◽  
Hippocampal Slice ◽  
Binding Protein ◽  
Glucose Deprivation ◽  
Mitogen Activated Protein Kinase ◽  
Oxygen Glucose Deprivation ◽  
Hippocampal Slice Cultures ◽  
Mitogen Activated Protein ◽  
Associated Proteins

Background Isoflurane preconditions neurons to improve tolerance of subsequent ischemia in both intact animal models and in in vitro preparations. The mechanisms for this protection remain largely undefined. Because isoflurane increases intracellular Ca2+ concentrations and Ca2+ is involved in many processes related to preconditioning, the authors hypothesized that isoflurane preconditions neurons via Ca2+-dependent processes involving the Ca2+- binding protein calmodulin and the mitogen-activated protein kinase-ERK pathway. Methods The authors used a preconditioning model in which organotypic cultures of rat hippocampus were exposed to 0.5-1.5% isoflurane for a 2-h period 24 h before an ischemia-like injury of oxygen-glucose deprivation. Survival of CA1, CA3, and dentate neurons was assessed 48 later, along with interval measurements of intracellular Ca2+ concentration (fura-2 fluorescence microscopy in CA1 neurons), mitogen-activated protein kinase p42/44, and the survival associated proteins Akt and GSK-3beta (in situ immunostaining and Western blots). Results Preconditioning with 0.5-1.5% isoflurane decreased neuron death in CA1 and CA3 regions of hippocampal slice cultures after oxygen-glucose deprivation. The preconditioning period was associated with an increase in basal intracellular Ca2+ concentration of 7-15%, which involved Ca2+ release from inositol triphosphate-sensitive stores in the endoplasmic reticulum, and transient phosphorylation of mitogen-activated protein kinase p42/44 and the survival-associated proteins Akt and GSK-3beta. Preconditioning protection was eliminated by the mitogen-activated extracellular kinase inhibitor U0126, which prevented phosphorylation of p44 during preconditioning, and by calmidazolium, which antagonizes the effects of Ca2+-bound calmodulin. Conclusions Isoflurane, at clinical concentrations, preconditions neurons in hippocampal slice cultures by mechanisms that apparently involve release of Ca2+ from the endoplasmic reticulum, transient increases in intracellular Ca2+ concentration, the Ca2+ binding protein calmodulin, and phosphorylation of the mitogen-activated protein kinase p42/44.

scholarly journals Increased tau Phosphorylation on Mitogen-Activated Protein Kinase Consensus Sites and Cognitive Decline in Transgenic Models for Alzheimer's Disease and FTDP-17: Evidence for Distinct Molecular Processes Underlying tau Abnormalities

2005 ◽  
Vol 25 (1) ◽  
pp. 278-293 ◽  
Author(s):  
Sarah L. Lambourne ◽  
Lynda A. Sellers ◽  
Toby G. Bush ◽  
Shewly K. Choudhury ◽  
Piers C. Emson ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Protein Kinase ◽  
Tau Phosphorylation ◽  
Mitogen Activated Protein Kinase ◽  
Chromosome 17 ◽  
Mapk Activation ◽  
Age Dependent ◽  
Mitogen Activated Protein ◽  
Activation Status

ABSTRACT Abnormal tau phosphorylation occurs in several neurodegenerative disorders, including Alzheimer's disease (AD) and frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17). Here, we compare mechanisms of tau phosphorylation in mouse models of FTDP-17 and AD. Mice expressing a mutated form of human tau associated with FTDP-17 (tauV337M) showed age-related increases in exogenous tau phosphorylation in the absence of increased activation status of a number of kinases known to phosphorylate tau in vitro. In a “combined” model, expressing both tauV337M and the familial amyloid precursor protein AD mutation APPV717I in a CT100 fragment, age-dependent tau phosphorylation occurred at the same sites and was significantly augmented compared to “single” tauV337M mice. These effects were concomitant with increased activation status of mitogen-activated protein kinase (MAPK) family members (extracellular regulated kinases 1 and 2, p38, and c-Jun NH2-terminal kinase) but not glycogen synthase kinase-3αβ or cyclin-dependent kinase 5. The increase in MAPK activation was a discrete effect of APPV717I-CT100 transgene expression as near identical changes were observed in single APPV717I-CT100 mice. Age-dependent deficits in memory were also associated with tauV337M and APPV717I-CT100 expression. The data reveal distinct routes to abnormal tau phosphorylation in models of AD and FTDP-17 and suggest that in AD, tau irregularities may be linked to processing of APP C-terminal fragments via specific effects on MAPK activation status.

scholarly journals p63α and γ Induce TAU Phosphorylation in Cultured Mammalian Cells

2010 ◽  
Vol 4 ◽  
pp. JEN.S6295
Author(s):  
Claudie Hooper ◽  
Reem Soliman ◽  
Simon Lovestone ◽  
Richard Killick
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Protein Kinase ◽  
Mammalian Cells ◽  
Neuronal Development ◽  
Glycogen Synthase ◽  
Tau Phosphorylation ◽  
Mitogen Activated Protein Kinase ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

Here we show by western blotting that transcriptionally active isoforms of p63 (p63α and p63γ) induce the phosphorylation of human 2N4R tau at the tau-1/AT8 epitope in HEK293a cells; a phospho-epitope increased in Alzheimer's disease. Confocal microscopy shows that tau and p63α are spatially separated intracellularly. Tau was found in the cytoskeletal compartment, whilst p63α was located in the nucleus, indicating that the effects of p63 on tau phosphorylation are indirectly mediated. Tau phosphorylation occurred independently of the known tau kinases, protein kinase C delta (PKCδ), c-Jun N-terminal kinase (JNK), extracellular-signal-regulated kinase (ERK), p38 mitogen-activated protein kinase (p38), glycogen synthase kinase 3 (GSK3), v-akt murine thymoma viral oncogene homolog (AKT) and cyclin-dependent kinase 5 (Cdk5) and the tau protein phosphatases (PP), PP1 and PP2A-Aα/β. Considering that p63 and tau are both associated with developmental processes, these findings have ramifications for neuronal development and synaptic plasticity and also neurodegenerative diseases such as Alzheimer's disease and other tauopathies.

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