Activation of protein kinase A and C prevents recovery from persistent depolarization produced by oxygen and glucose deprivation in rat hippocampal neurons

2012 ◽  
Vol 107 (9) ◽  
pp. 2517-2525 ◽  
Author(s):  
Y. Murai ◽  
Y. Okabe ◽  
E. Tanaka
Keyword(s):  
Protein Kinase ◽  
Adenylate Cyclase ◽  
Hippocampal Neurons ◽  
Kinase Inhibitor ◽  
Glucose Deprivation ◽  
Dependent Manner ◽  
Dependent Protein Kinase ◽  
Α Subunit ◽  
Oxygen And Glucose Deprivation ◽  
Dependent Protein

Intracellular recordings were made from rat hippocampal CA1 neurons in rat brain slice preparations to investigate whether cAMP-dependent protein kinase (PKA) and calcium/phospholipid-dependent protein kinase C (PKC) contribute to the membrane dysfunction induced by oxygen and glucose deprivation (OGD). Superfusion of oxygen- and glucose-deprived medium produced a rapid depolarization ∼5 min after the onset of the superfusion. When oxygen and glucose were reintroduced immediately after the rapid depolarization, the membrane depolarized further (persistent depolarization) and reached 0 mV after 5 min from the reintroduction. The pretreatment of the slice preparation with PKA inhibitors, H-89 and Rp-cAMPS, and an adenylate cyclase inhibitor, SQ 22, 536, significantly restored the membrane toward the preexposure potential level after the reintroduction of oxygen and glucose in a concentration-dependent manner. On the other hand, a phospholipase C inhibitor, U73122, a PKC inhibitor, GF109203X, and a nonselective protein kinase inhibitor, staurosporine, also significantly restored the membrane after the reintroduction. Moreover, an inositol-1,4,5-triphosphate receptor antagonist, 2-aminoethyl diphenylborinate, and calmodulin inhibitors, trifluoperazine and W-7, significantly restored the membrane after the reintroduction, while neither an α-subunit-selective antagonist for stimulatory G protein, NF449, a Ca2+/calmodulin-dependent kinase II inhibitor, KN-62, nor a myosin light chain kinase inhibitor, ML-7, significantly restored the membrane after the reintroduction. These results suggest that the activation of PKA and/or PKC prevents the recovery from the persistent depolarization produced by OGD. The Ca2+/calmodulin-stimulated adenylate cyclase may contribute to the activation of PKA.

scholarly journals Staurosporine, a Novel Protein Kinase C Inhibitor, Prevents Postischemic Neuronal Damage in the Gerbil and Rat

1990 ◽  
Vol 10 (5) ◽  
pp. 646-653 ◽  
Author(s):  
Hideaki Hara ◽  
Hiroshi Onodera ◽  
Mikio Yoshidomi ◽  
Yuzuru Matsuda ◽  
Kyuya Kogure
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Kinase Inhibitor ◽  
Neuronal Damage ◽  
Pyramidal Cells ◽  
Protein Kinase Inhibitors ◽  
Dependent Manner ◽  
Dependent Protein Kinase ◽  
Kinase C ◽  
Dependent Protein

The protective effects of protein kinase inhibitors and a calmodulin kinase inhibitor (W-7) against ischemic neuronal damage were examined in the CA1 subfield of the hippocampus. Staurosporine, KT5720, and KT5822 were used as inhibitors of protein kinase C (PKC), cyclic AMP–dependent protein kinase, and cyclic GMP–dependent protein kinase, respectively. All test compounds were injected topically into the CA1 subfield of the hippocampus. In the gerbil ischemia model, staurosporine (0.1–10 ng) administered 30 min before ischemia prevented neuronal damage in a dose-dependent manner. However, KT5720, KT5822, and W-7 were ineffective, even at a dose of 10 ng. In the rat ischemia model, staurosporine (10 ng) also prevented neuronal damage when administered before ischemic insult, although staurosporine administered 10 or 180 min after recirculation was ineffective. These results suggest the involvement of PKC in CA1 pyramidal cell death after ischemia and that the fate of vulnerable CA1 pyramidal cells through PKC-mediated processes could be determined during the early recirculation period.

Guanylyl cyclase stimulatory coupling to KCachannels

2000 ◽  
Vol 279 (6) ◽  
pp. C1938-C1945 ◽  
Author(s):  
M. Nara ◽  
P. D. K. Dhulipala ◽  
G. J. Ji ◽  
U. R. Kamasani ◽  
Y.-X. Wang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase ◽  
Guanylyl Cyclase ◽  
Phosphorylation Site ◽  
Nitric Oxide Donor ◽  
Dependent Manner ◽  
Dependent Protein Kinase ◽  
Α Subunit ◽  
Dependent Protein ◽  
Spermine Nonoate

We coexpressed the human large-conductance, calcium-activated K (KCa) channel (α- and β-subunits) and rat atrial natriuretic peptide (ANP) receptor genes in Xenopus oocytes to examine the mechanism of guanylyl cyclase stimulatory coupling to the channel. Exposure of oocytes to ANP stimulated whole cell KCa currents by 21 ± 3% (at 60 mV), without altering current kinetics. Similarly, spermine NONOate, a nitric oxide donor, increased KCa currents (20 ± 4% at 60 mV) in oocytes expressing the channel subunits alone. Stimulation of KCacurrents by ANP was inhibited in a concentration-dependent manner by a peptide inhibitor of cGMP-dependent protein kinase (PKG). Receptor/channel stimulatory coupling was not completely abolished by mutating the cAMP-dependent protein kinase phosphorylation site on the α-subunit (S869; Nars M, Dhulipals PD, Wang YX, and Kotlikoff MI. J Biol Chem 273: 14920–14924, 1998) or by mutating a neighboring consensus PKG site (S855), but mutation of both residues virtually abolished coupling. Spermine NONOate also failed to stimulate channels expressed from the double mutant cRNAs. These data indicate that nitric oxide donors stimulate KCa channels through cGMP-dependent phosphorylation and that two serine residues (855 and 869) underlie this stimulatory coupling.

scholarly journals Augmentation of bursting pacemaker activity by serotonin in an identified Achatina fulica neurone: an increase in sodium- and calcium-activated negative slope resistance via cyclic-AMP-dependent protein phosphorylation

1993 ◽  
Vol 175 (1) ◽  
pp. 33-44
Author(s):  
K. Funase ◽  
K. Watanabe ◽  
M. Onozuka
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Kinase Inhibitor ◽  
Negative Slope ◽  
Pacemaker Activity ◽  
Dependent Manner ◽  
Achatina Fulica ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Dose Dependent

The mechanism of serotonin (5-HT) action on bursting activity was examined in a bursting pacemaker neurone of the snail Achatina fulica. 5-HT augmented both the depolarizing and post-burst-hyperpolarizing phases of the bursting cycle in a dose-dependent manner. This biogenic amine also enhanced the negative slope resistance (NSR), which was normally detectable at membrane potentials between −40 and −20 mV, and produced another NSR at voltages between −20 and 0 mV. The former NSR disappeared in Na(+)-free saline and the latter was abolished by replacement with Co(2+)-substituted Ca(2+)-free saline. Both isobutylmethylxanthine, extracellular applied, and intracellularly applied cyclic AMP simulated a 5-HT effect on the current-voltage relationships. In contrast, the 5-HT effect was suppressed in a dose-dependent manner by prior treatment with a cyclic-AMP-dependent protein kinase inhibitor, isoquinoline sulphonamide. Similar suppression was observed after intracellular injection of a cyclic-AMP-dependent protein kinase inhibitor isolated from bovine muscle. These results suggest that 5-HT may augment the bursting pacemaker activity by its stimulatory effect on both the slow Na+ channels and the Ca2+ channels through cyclic-AMP-dependent protein phosphorylation.

A novel 5-HT1-like receptor subtype mediates cAMP synthesis in porcine pial vein

1995 ◽  
Vol 268 (4) ◽  
pp. H1383-H1389 ◽  
Author(s):  
M. Ueno ◽  
T. Ishine ◽  
T. J. Lee
Keyword(s):  
Protein Kinase ◽  
Kinase Inhibitor ◽  
Phosphodiesterase Inhibitor ◽  
Protein Kinase Inhibitor ◽  
Receptor Subtype ◽  
Dependent Manner ◽  
Dependent Protein Kinase ◽  
Cyclic Monophosphate ◽  
Dependent Protein ◽  
Ics 205 930

The 5-hydroxytryptamine (5-HT) receptor subtype mediating 5-HT inhibition of spontaneous rhythmic contractions (SRC) in the porcine pial vein was characterized. Results from pharmacological studies using in vitro tissue bath techniques indicated that the inhibitory effects of 5-HT on SRC were qualitatively and quantitatively mimicked by 5-HT1-like agonists 5-methoxytryptamine (5-MT) and 5-carboxamidotryptamine (5-CT). 5-HT-, 5-MT-, and 5-CT-induced inhibitions of SRC were attenuated in a concentration-dependent manner by methysergide, which yielded similar pA2 values against these three agonists, suggesting that 5-HT, 5-MT, and 5-CT act on the same 5-HT1-like receptors. 5-MT inhibition of SRC was not affected by blocking 5-HT2 (with ketanserin and spiperone), 5-HT3 (with MDL-72222 and ICS-205-930), or 5-HT4 (with ICS-205-930) receptors. Neither was 5-MT inhibition of SRC affected by blocking 5-HT1A (with propranolol and spiperone), 5-HT1B (with propranolol), or 5-HT1C (with ketanserin) receptors. Furthermore, 5-HT and 5-MT inhibitions of SRC were enhanced by cilostazol [a selective adenosine 3',5'-cyclic monophosphate (cAMP) phosphodiesterase inhibitor] and were diminished by KT-5720 (a cAMP-dependent protein kinase inhibitor) but were not affected by M&B-22948 [a selective guanosine 3',5'-cyclic monophosphate (cGMP) phosphodiesterase inhibitor] or KT-5823 (a cGMP-dependent protein kinase inhibitor). Biochemical studies further demonstrated that 5-HT inhibition of SRC in porcine pial veins was accompanied by an increase in cAMP, but not cGMP, synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Genetic Involvement of a cAMP-Dependent Protein Kinase in a G Protein Signaling Pathway Regulating Morphological and Chemical Transitions in Aspergillus nidulans

Genetics ◽  
2001 ◽  
Vol 157 (2) ◽  
pp. 591-600
Author(s):  
Kiminori Shimizu ◽  
Nancy P Keller
Keyword(s):  
Protein Kinase ◽  
Aspergillus Nidulans ◽  
Signaling Pathway ◽  
G Protein ◽  
Radial Growth ◽  
Morphological Development ◽  
Dependent Protein Kinase ◽  
Α Subunit ◽  
Camp Dependent Protein Kinase ◽  
Dependent Protein

Abstract In the filamentous fungus Aspergillus nidulans, a heterotrimeric G protein α-subunit and an RGS domain protein, encoded by fadA and flbA, respectively, regulate production of the carcinogenic metabolite sterigmatocystin (ST) and asexual spores (i.e., conidia). We investigated the genetic involvement of the cAMP-dependent protein kinase catalytic subunit (PkaA), a potential downstream target of FadA activity, in ST production and conidiation. Relative to wild type, sporulation was decreased in the pkaA overexpression strain but was not totally absent, as occurs in ΔflbA or fadAG42R (fadA-dominant active) strains. Deletion of pkaA resulted in a hyper-conidiating strain with limited radial growth. This phenotype was epistatic to mutation in flbA or fadA; the double mutants ΔpkaA; ΔflbA and ΔpkaA; fadAG42R recovered sporulation and their radial growth was severely restricted. PkaA overexpression also negatively regulated AflR, the ST biosynthesis-specific transcription factor, both transcriptionally and post-transcriptionally. Deletion of pkaA restored ST production in the ΔflbA background but not in the fadAG42R background. These data provide genetic evidence that the FlbA/FadA signaling pathway regulating ST production and morphological development is partially mediated through PkaA.

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