Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.3.16 (calcineurin)
17,112 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This immunohistochemical study compares the expression of synaptophysin (SYP) in the striatum in Huntington's disease (HD) with that of calcineurin (CaN), a marker for striatal medium-sized spinous neurons. As compared to controls, in the HD striatum there was a significant loss of SYP immunoreactivity with residual staining displaying an inhomogeneous pattern, which strikingly resembled that of CaN. Our results may indicate that there is a synaptic loss in the striatum with HD and this is most likely due to loss of medium-sized spinous neurons characteristic of this disease.
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PMID:Synaptophysin expression in the striatum in Huntington's disease. 214 51

The afferent nerve terminal in the human globus pallidus, which receives the projection nerve fibers from both the striatum and the subthalamic nucleus, were clearly visualized immunohistochemically using antibodies to calcineurin, synaptophysin, Met-enkephalin (MEnk) and substance P (SP). In normal control case, MEnk and SP-like immunoreactivities were densely localized in the external and internal pallidal segments, respectively, whereas calcineurin and synaptophysin were distributed throughout the globus pallidus. Calcineurin, synaptophysin, MEnk and SP-like immunoreactive peroxidase products decorated most of the long radiating dendrites and the cell bodies of the pallidal neurons. In the cases with Huntington's disease (HD) and striatonigral degeneration (SND), marked loss of calcineurin, MEnk and SP-like immunoreactivities was seen in the globus pallidus corresponding to areas of striatal neurodegeneration, whereas synaptophysin immunoreactivity remained in areas which revealed almost complete loss of calcineurin, MEnk and SP-like immunoreactivities. Calcineurin, MEnk and SP, which show difference in their localization patterns, may provide reliable markers for the striatal efferent nerve terminals, and synaptophysin for the entire pallidal afferent nerve terminals. This report demonstrates the distribution patterns of these neurochemical molecules in the globus pallidus with HD and SND.
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PMID:Immunohistochemical visualization of afferent nerve terminals in human globus pallidus and its alteration in neostriatal neurodegenerative disorders. 247 14

The neostriatum of 7 autopsied patients with Huntington's disease (HD) was examined immunohistochemically using purified antibody against calcineurin, which may be present only in the medium-size spinous neurons of the mammalian striatum. This study revealed a marked loss of calcineurin-positive cells in the caudate nucleus and the putamen in all HD patients, compared with control subjects, and there was some variation among the HD patients. Four HD patients showed significantly lower density of calcineurin-positive cells in the caudate nucleus than in the putamen. The remaining calcineurin-positive cells in the caudate nucleus and the putamen had a mosaic-like pattern, demonstrating a subregional difference in distribution. This finding suggests that there are subregional as well as compartmental differences in the vulnerability of the calcineurin-positive cells in the striatum of patients with HD.
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PMID:An immunohistochemical investigation of the human neostriatum in Huntington's disease. 254 63

Calcineurin immunoreactivity has been successfully detected in formalin-fixed paraffin-embedded postmortem human brain tissue using the peroxidase-antiperoxidase method. We have examined two autopsy cases with Huntington's disease (HD), three cases with Parkinson's disease, and two senile patients as controls. In the controls, calcineurin immunoreactivity was present in neuronal cells only and highly concentrated in the caudate nucleus, putamen, globus pallidus (striato-pallidal pathway), substantia nigra (striato-nigral pathway) and hippocampal formation. These localizations were similar to those identified in rat brain. There was a marked depletion of neurons containing calcineurin in the caudate nucleus and putamen, and a marked reduction of calcineurin-immunoreactive nerve fibers in the globus pallidus and substantia nigra were found in the cases with HD, but not in those with Parkinson's disease. These findings suggest that calcineurin can be a useful and specific index of neuronal degeneration in the caudato-putamen resulting from extrapyramidal disease, and that the calcineurin-immunostaining method can be a valuable tool for clarifying the anatomy of the human extrapyramidal system.
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PMID:Calcineurin in human brain and its relation to extrapyramidal system. Immunohistochemical study on postmortem human brains. 295 Jul 15

We investigated the role of neurofilament (NF) proteins in Alzheimer disease (AD) neurofibrillary degeneration. The levels and degree of phosphorylation of NF proteins in AD neocortex were determined by Western blots developed with a panel of phosphorylation-dependent NF antibodies. Levels of all three NF subunits and the degree of phosphorylation of NF-H and NF-M were significantly increased in AD as compared to Huntington disease brains used as control tissue. The increase in the levels of NF-H and NF-M was 1.7- and 1.5-fold (P<0.01) as determined by monoclonal antibody SMI33, and was 1.6-fold (P<0.01) in NF-L using antibody NR4. The phosphorylation of NF-H and NF-M in AD was increased respectively at the SMI31 epitope by 1.6- and 1.9-fold (P<0.05) and at the SMI33 epitope by 2.7- and 1.3-fold (P<0.01 and P<0.05). Essentially similar effects were observed in SY5Y human neuroblastoma cells when treated with okadaic acid, an inhibitor of protein phosphatase (PP)-2A and -1. This is the first biochemical evidence which unambiguously demonstrates the hyperphosphorylation and the accumulation of NF subunits in AD brain, and shows that the inhibition of PP-2A/PP-1 activities can lead to the hyperphosphorylation of NF-H and NF-M subunits.
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PMID:Hyperphosphorylation and accumulation of neurofilament proteins in Alzheimer disease brain and in okadaic acid-treated SY5Y cells. 1168 63

Motor and cognitive deficits in Huntington's disease (HD) are likely caused by progressive neuronal dysfunction preceding neuronal cell death. Synapsin I is one of the major phosphoproteins regulating neurotransmitter release. We report here an abnormal phosphorylation state of synapsin I in the striatum and the cerebral cortex of R6/2 transgenic mice expressing the HD mutation. These changes are mostly characterized by an early overphosphorylation at sites 3-5, whereas phosphorylation at site 1 remains unchanged and at site 6 becomes reduced only close to the end stage of the disease. Such changes do not result from modification in protein expression levels. However, we show a decreased expression of the calcineurin regulatory subunit-B, which may contribute to an imbalance between kinase and phosphatase activities. Together the results suggest that an early impairment in synapsin phosphorylation-dephosphorylation may alter synaptic vesicle trafficking and lead to defective neurotransmission in HD.
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PMID:Abnormal phosphorylation of synapsin I predicts a neuronal transmission impairment in the R6/2 Huntington's disease transgenic mice. 1221 45

Lithium has long been one of the primary drugs used to treat bipolar mood disorder. However, neither the etiology of this disease nor the therapeutic mechanism(s) of this drug is well understood. Several lines of clinical evidence suggest that lithium has neurotrophic actions. For example chronic lithium treatment increases the volume of gray matter and the content of N-acetyl-aspartate, a cell survival marker, in bipolar mood disorder patients (Moore et al., 2000). Moreover, treatment with this mood-stabilizer suppresses the decrease in the volume of the subgenual pre-frontal cortex found in bipolar patients (Drevets, 2001). To elucidate molecular mechanisms underlying the neuroprotective and neurotrophic actions of lithium, we employed a preparation of cultured cortical neurons prepared form embryonic rats. We found that treatment with therapeutic doses (0.2-1.2 mM) of lithium robustly protects cortical neurons from multiple insults, notably glutamate-induced excitotoxicity. The neuroprotection against glutamate excitotoxicity is time-dependent, requiring treatment for 5-6 days for maximal effect, and is associated with a reduction in NMDA receptor-mediated Ca2+ influx. The latter is correlated with a decrease in Tyrosine 1472 phosphorylation levels in the NR2B subunit of NMDA receptors and a loss of Src kinase activity which is involved in NR2B tyrosine phosphorylation. Neither the activity of total tyrosine protein kinase nor that of tyrosine protein phosphatase is affected by this drug, indicating the selectivity of the modulation. Lithium neuroprotection against excitotoxicity is inhibited by a BDNF-neutralizing antibody and K252a, a Trk antagonist. Lithium treatment time-dependently increases the intracellular level of BDNF in cortical neurons and activates its receptor, TrkB. The neuroprotection can be completely blocked by either heterozygous or homozygous knockout of the BDNF gene. These results suggest a central role of BDNF and TrkB in mediating the neuroprotective effects of this mood-stabilizer. Finally, long-term lithium treatment of cortical neurons stimulates the proliferation of their progenitor cells detected by co-labeling with BrdU and nestin. Lithium pretreatment also blocks the decrease in progenitor proliferation induced by glutamate, glucocorticoids and haloperidol, suggesting a role in CNS neuroplasticity. We used animal models to investigate further therapeutic potentials for lithium. In the MCAO/reperfusion model of stroke, we found that post-insult treatment with lithium robustly reduced infarct volume and neurological deficits. These beneficial effects were evident when therapeutic concentrations of lithium were injected at least up to 3 h after ischemic onset. The neuroprotection was associated with activation of heat-shock factor-1 and induction of heat-shock protein-70, a cytoprotective protein. In a rat excitotoxic model of Huntington's disease, the excitotoxin-induced loss of striatal medium-sized neurons was markedly reduced by lithium. This lithium protection was correlated with up-regulation of cytoprotective Bcl-2 and down-regulation of apoptotic proteins p53 and Bax, and neurons showing DNA damage and caspase-3 activation. Taken together, our results provide a new insight into the molecular mechanisms involved in lithium neuroprotection against glutamate excitotoxicity. Moreover, these novel molecular and cellular actions might contribute to the neurotrophic and neuroprotective actions of this mood-stabilizer in patients, and could be related to its clinical efficacy for treating mood disorder patients. Clearly, mood-stabilizers may have expanded use for treating excitotoxin-related neurodegenerative diseases.
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PMID:[Neuroprotective actions of lithium]. 1270 Dec 14

Cell signaling entails a host of post-translational modifications of effector-proteins. These modifications control signal transmission by regulating the activity, localization or half-life of the effector-protein. Prominent oxidative modifications induced by cell-signaling reactive oxygen species (ROS) are cysteinyl modifications such as S-nitrosylation, sulfenic acid and disulfide formation. Disulfides protect protein sulfhydryls against oxidative destruction and simultaneously influence cell signaling by engaging redox-regulatory sulfhydryls in effector-proteins. The types of disulfides implicated in signaling span (1) protein S-glutathionylation, e.g. as a novel mode of Ras activation through S-glutathionylation at Cys-118 in response to a hydrogen-peroxide burst, (2) intra-protein disulfides, e.g. in the regulation of the stability of the protein phosphatase Cdc25C by hydrogen-peroxide, (3) inter-protein disulfides, e.g. in the hydrogen peroxide-mediated inactivation of receptor protein-tyrosine phosphatase alpha (RPTPalpha) by dimerization and (4) protein S-cysteaminylation by cystamine. Cystamine is a byproduct of pantetheinase-catalyzed pantothenic acid recycling from pantetheine for biosynthesis of Coenzyme A (CoA), a ubiquitous and metabolically indispensable cofactor. Cystamine inactivates protein kinase C-epsilon (PKCepsilon), gamma-glutamylcysteine synthetase and tissue transglutaminase by S-cysteaminylation-triggered mechanisms. The importance of protein S-cysteaminylation in signal transmission in vivo is evident from the ability of cystamine administration to rescue the intestinal inflammatory-response deficit of pantetheinase knockout mice. These mice lack the predominant epithelial pantetheinase isoform and have sharply reduced levels of cystamine/cysteamine in epithelial tissues. In addition, intraperitoneal administration of cystamine significantly delays neurodegenerative pathogenesis in a Huntington's disease mouse model. Thus, cystamine may serve as a prototype for the development of novel therapeutics that target effector-proteins regulated by S-cysteaminylation.
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PMID:Post-translational disulfide modifications in cell signaling--role of inter-protein, intra-protein, S-glutathionyl, and S-cysteaminyl disulfide modifications in signal transmission. 1603 22

Huntington's disease (HD) is caused by an abnormal expanded polyglutamine (polyQ) repeat in the huntingtin protein. Insulin-like growth factor-1 acting through the prosurvival kinase Akt mediates the phosphorylation of huntingtin at S421 and inhibits the toxicity of polyQ-expanded huntingtin in cell culture, suggesting that compounds enhancing phosphorylation are of therapeutic interest. However, it is not clear whether phosphorylation of S421 is crucial in vivo. Using a rat model of HD based on lentiviral-mediated expression of a polyQ-huntingtin fragment in the striatum, we demonstrate here that phosphorylation of S421 is neuroprotective in vivo. We next demonstrate that calcineurin (CaN), a calcium/calmodulin-regulated Ser/Thr protein phosphatase, dephosphorylates S421 in vitro and in cells. Inhibition of calcineurin activity, either by overexpression of the dominant-interfering form of CaN or by treatment with the specific inhibitor FK506, favors the phosphorylation of S421, restores the alteration in huntingtin S421 phosphorylation in HD neuronal cells, and prevents polyQ-mediated cell death of striatal neurons. Finally, we show that administration of FK506 to mice increases huntingtin S421 phosphorylation in brain. Collectively, these data highlight the importance of CaN in the modulation of S421 phosphorylation and suggest the potential use of CaN inhibition as a therapeutic approach to treat HD.
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PMID:Inhibition of calcineurin by FK506 protects against polyglutamine-huntingtin toxicity through an increase of huntingtin phosphorylation at S421. 1645 87

Excitotoxicity has been proposed as one of the mechanisms involved in the specific loss of striatal neurons that occurs in Huntington's disease. Here, we studied the role of calcineurin in the vulnerability of striatal neurons expressing mutant huntingtin to excitotoxicity. To this end, we induced excitotoxicity by adding NMDA to a striatal precursor cell line expressing full-length wild-type (STHdh(Q7/Q7)) or mutant (STHdh(Q111/Q111)) huntingtin. We observed that cell death appeared earlier in STHdh(Q111/Q111) cells than in STHdh(Q7/Q7) cells. Interestingly, these former cells expressed higher levels of calcineurin A that resulted in a greater increase of its activity after NMDA receptor stimulation. Moreover, transfection of full-length mutant huntingtin in different striatal-derived cells (STHdh(Q7/Q7), M213 and primary cultures) increased calcineurin A protein levels. To determine whether high levels of calcineurin A might account for the earlier activation of cell death in mutant huntingtin knock-in cells, wild-type cells were transfected with calcineurin A. Calcineurin A-transfected STHdh(Q7/Q7) cells displayed a significant increase in cell death compared with that recorded in green fluorescent protein-transfected cells after NMDA treatment. Notably, addition of the calcineurin inhibitor FK-506 produced a more robust reduction in cell death in mutant huntingtin knock-in cells than it did in wild-type cells. These results suggest that high levels of calcineurin A could account for the increased vulnerability of striatal cells expressing mutant huntingtin to excitotoxicity.
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PMID:Calcineurin is involved in the early activation of NMDA-mediated cell death in mutant huntingtin knock-in striatal cells. 1822 65


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