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Abstract: We investigated the postnatal alterations of neuronal nuclei (NeuN)-positive neurons, parvalbumin (PV)-positive interneurons, neuronal nitric oxide synthase (nNOS)-positive interneurons, and neurotrophic factors in the mouse striatum and frontal cortex using immunohistochemistry. NeuN, PV, nNOS, nerve growth factor (NGF), and brain-derived neurotrophic factor (BDNF) immunoreactivity were measured in 1-, 2-, 4- and 8-week-old mice. Total number of NeuN-positive neurons was unchanged in the mouse striatum and frontal cortex from 1 up to 8 weeks of age. In contrast, a significant decrease in the number of PV-positive interneurons was observed in the striatum and frontal cortex of 1-, 2- and 4-week-old mice. Furthermore, a significant increase of nNOS-positive interneurons was found in the striatum and frontal cortex of 1- and/or 2-week-old mice. NGF-positive neurons were unchanged in the mouse striatum from 1 up to 8 weeks of age. In the frontal cortex, a significant increase in the number of NGF-positive neurons was observed only in 1-week-old mice. In contrast, a significant increase in the number of NGF-positive glia 1 cells was found in the striatum and frontal cortex of 4-week-old mice. Our double-labeled immunostaining showed that nNOS immunoreactivity was not found in PV-immunopositive interneurons. Furthermore, BDNF immunoreactivity was observed in both nNOS-positive and PV-positive interneurons in the striatum of 1- or 2-week-old mice. These results show that the maturation of nNOS-immunopositive interneurons precedes the maturation of PV-immunopositive interneurons in the striatum and frontal cortex during postnatal development. Furthermore, our results demonstrate that the expression of BDNF may play some role in the maturation of interneurons in the striatum and frontal cortex during postnatal development. Moreover, our findings suggest that the expression of NGF in glia cells may play some role in the maturation of glial cells and PV-positive interneurons in the striatum and frontal cortex during postnatal development. [Copyright &y& Elsevier]

DY-9760e (3-[2-[4-(3-chloro-2-methylphenyl)-1-piperazinyl]ethyl]-5,6-dimethoxy-1-(4-imidazolylmethyl)-1 H-indazole dihydrochloride-3.5 hydrate) inhibits Ca2+/CaM-dependent nitric oxide synthase (NOS), thereby inhibiting nitric oxide (NO) production. In cardiomyocytes from ischemic rat heart NO and superoxide levels are increased causing protein tyrosine nitration. In hearts subjected to ischemia/reperfusion DY-9760e totally abolishes protein tyrosine nitration. Notably, DY-9760e also inhibits calpain and cas-pase-3 activation that occurs prior to apoptosis in cardiomyocytes. In ischemic hearts fodrin is the substrate for calpain. DY-9760e inhibits fodrin breakdown in the peri-infarct area rather than in the infarct core. In the ischemic rat brain DY-9760e inhibits caspase-3-induced proteolysis of calpastatin, an endogenous calpain inhibitor, suggesting that crosstalk between calpain and caspase-3 is mediated by calpastatin breakdown. Thus, DY-9760e rescues neurons and cardiomyocytes from ischemic injury by inhibiting crosstalk between calpain and caspase-3 as well as protein tyrosine nitration. [ABSTRACT FROM AUTHOR]

Multifunctional Ca2+/calmodulin-dependent protein kinases (CaMKs) including CaMKI, II and IV, are thought to regulate a variety of neuronal functions. Unlike CaMKII, which is regulated by autophosphorylation, CaMKI as well as CaMKIV are activated by CaMKK. In this study, we examined the cellular and subcellular localization of CaMKIδ, a recently identified fourth isoform of CaMKI, in the mature brain. In situ hybridization analysis demonstrated wide expression of CaMKIδ mRNA in the adult mouse brain with prominent expression in the hippocampal pyramidal cells. FLAG-tagged CaMKIδ was localized at the cytoplasm and neurites without nuclear immunoreactivity in approximately 80% of the transfected primary hippocampal neurons. The stimulation with either KCl depolarization or glutamate triggered the nuclear localization of FLAG-tagged CaMKIδ by two-fold with a peak at 1 min. In contrast, the catalytically inactive mutants of CaMKIδ remained cytoplasmic without nuclear translocation during KCl depolarization, indicating the requirement of its activation for the nuclear translocation. Furthermore, we showed that immunoprecipitated CaMKIδ could phosphorylate cAMP response element binding protein (CREB)α in vitro and that the over-expression of CaMKIδ enhanced GAL4-CREB-luciferase activity in PC12 cells stimulated by KCl depolarization. Our present study provides the first evidence for the possible involvement of CaMKIδ in nuclear functions through its nuclear translocation in response to stimuli that trigger intracellular Ca2+ influx. [ABSTRACT FROM AUTHOR]

A circadian clock located in the suprachiasmatic nucleus (SCN) regulates the period of physiological and behavioural rhythms to approximately 24 h. Lithium can lengthen the period of circadian rhythms in most organisms although little is known about the underlying mechanism. In the present study, we examined Drosophila shaggy ortholog glycogen synthase kinase-3 (GSK-3) protein expression in the SCN after lithium treatment. When locomotor activity was assessed, we found an association between the effect of lithium and the period of circadian oscillation as well as the level of GSK-3 protein expression. The decreased expression of GSK-3 and increased expression of phosphorylated GSK-3 (pGSK-3) resulted in an antiphasic circadian rhythm between the two in the SCN of lithium-treated mice housed under both light-dark and constant dark conditions. The enzyme activity of GSK-3 in the SCN was low when the level of pGSK-3 protein was high, as examined by immunoblotting analysis. Thus, GSK-3 enzyme activity has a correlation with the expression of GSK-3 protein in the SCN. Although both GSK-3 and pGSK-3 proteins are also expressed in the arcuate nucleus, lithium did not affect their expression. Based on the association that we found between lengthened circadian period and GSK-3 protein and GSK-3 activity in the SCN, we suggest that GSK-3 plays a role in regulating the period of the mammalian circadian pacemaker. [ABSTRACT FROM AUTHOR]

Multifunctional Ca2+/calmodulin-dependent protein kinases (CaMKs) including CaMKI, II and IV, are thought to regulate a variety of neuronal functions. Unlike CaMKII, which is regulated by autophosphorylation, CaMKI as well as CaMKIV are activated by CaMKK. In this study, we examined the cellular and subcellular localization of CaMKIdelta, a recently identified fourth isoform of CaMKI, in the mature brain. In situ hybridization analysis demonstrated wide expression of CaMKIdelta mRNA in the adult mouse brain with prominent expression in the hippocampal pyramidal cells. FLAG-tagged CaMKIdelta was localized at the cytoplasm and neurites without nuclear immunoreactivity in approximately 80% of the transfected primary hippocampal neurons. The stimulation with either KCl depolarization or glutamate triggered the nuclear localization of FLAG-tagged CaMKIdelta by two-fold with a peak at 1 min. In contrast, the catalytically inactive mutants of CaMKIdelta remained cytoplasmic without nuclear translocation during KCl depolarization, indicating the requirement of its activation for the nuclear translocation. Furthermore, we showed that immunoprecipitated CaMKIdelta could phosphorylate cAMP response element binding protein (CREB)alphain vitro and that the over-expression of CaMKIdelta enhanced GAL4-CREB-luciferase activity in PC12 cells stimulated by KCl depolarization. Our present study provides the first evidence for the possible involvement of CaMKIdelta in nuclear functions through its nuclear translocation in response to stimuli that trigger intracellular Ca2+ influx.