Rho kinase mediates serum-induced contraction in fibroblast fibers independent of myosin LC20 phosphorylation

2003 ◽  
Vol 284 (3) ◽  
pp. C599-C606 ◽  
Author(s):  
Hiromi Nobe ◽  
Koji Nobe ◽  
Fabeha Fazal ◽  
Primal de Lanerolle ◽  
Richard J. Paul
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Light Chain ◽  
Kinase Inhibitor ◽  
Calf Serum ◽  
Rho Kinase ◽  
Fiber Formation ◽  
Dependent Manner ◽  
Sustained Contraction ◽  
Kinase C

Fibroblasts form fibers when grown in culture medium containing native type 1 collagen. The contractile forces generated can be precisely quantified and used to analyze the signal transduction pathways regulating fibroblast contraction. Calf serum (30%) induces a sustained contraction that is accompanied by a transient increase in intracellular calcium ([Ca2+]i). W-7, a calmodulin inhibitor, KN-62, an inhibitor of calcium/calmodulin-dependent protein kinase, and ML-7, a myosin light-chain kinase inhibitor, had no effects on either the contraction or the [Ca2+]i responses. Neither genistein, a tyrosine kinase inhibitor, nor calphostin C, a protein kinase C inhibitor, had major effects on force or [Ca2+]i. In contrast, the Rho kinase inhibitors (R)-(+)- trans-N-(4-pyridyl)-4-(1-aminoethyl)-cyclohexanecarboxamide (Y-27632) and HA1077 depressed the contraction in a dose-dependent manner without affecting the [Ca2+]iresponse. Stress fiber formation was also suppressed by Y-27632. Surprisingly, calf serum, Y-27632, and calf serum plus Y-27632 did not alter mono- or diphosphorylation of the myosin regulatory light chain (MRLC) compared with control untreated fibers. These results suggest that the sustained contraction of NIH 3T3 fibroblast fibers induced by calf serum is mediated by Rho kinase but is independent of a sustained increase in [Ca2+]i, calcium/calmodulin- or protein kinase C-dependent pathways, or increases in MRLC phosphorylation.

α1-Adrenoceptor-Gq-RhoA signaling is upregulated to increase myofibrillar Ca2+ sensitivity in failing hearts

2001 ◽  
Vol 281 (2) ◽  
pp. H637-H646 ◽  
Author(s):  
Nobuhiro Suematsu ◽  
Shinji Satoh ◽  
Shintaro Kinugawa ◽  
Hiroyuki Tsutsui ◽  
Shunji Hayashidani ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Expression ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Kinase Inhibitor ◽  
Rho Kinase ◽  
Adrenergic Stimulation ◽  
Regulatory Myosin Light Chain ◽  
Kinase C

α1-Adrenergic stimulation, coupled to Gq, has been shown to promote heart failure. However, the role of α1-adrenergic signaling in the regulation of myocardial contractility in failing myocardium is still poorly understood. To investigate this, we observed 1) the effect of phenylephrine on myofibrillar Ca2+ sensitivity in α-toxin-skinned cardiomyocytes, and 2) protein expression of Gq, RhoA, and myosin light chain phosphorylation using tachypacing-induced canine failing hearts. Phenylephrine significantly increased myofibrillar Ca2+ sensitivity in failing but not in normal cardiomyocytes. Whereas Y-27632 (Rho kinase inhibitor) blocked the phenylephrine-induced Ca2+ sensitization in the failing myocytes, calphostin C (protein kinase C inhibitor) had no effect on Ca2+ sensitization. The protein expression of Gαq and RhoA and the phosphorylation level of regulatory myosin light chain significantly increased in the failing myocardium. Our results suggest that α1-adrenoceptor-Gq signaling is upregulated in the failing myocardium to increase the myofibrillar Ca2+sensitivity mainly through the RhoA-Rho kinase pathway rather than through the protein kinase C pathway.

Serotonin Reduces the Hyperpolarization-Activated Current (Ih) in Ventral Tegmental Area Dopamine Neurons: Involvement of 5-HT2 Receptors and Protein Kinase C

2003 ◽  
Vol 90 (5) ◽  
pp. 3201-3212 ◽  
Author(s):  
Zhaoping Liu ◽  
E. Bradshaw Bunney ◽  
Sarah B. Appel ◽  
Mark S. Brodie
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Ventral Tegmental Area ◽  
Kinase Inhibitor ◽  
Brain Slices ◽  
Dopamine Neurons ◽  
Dependent Manner ◽  
Cationic Current ◽  
Kinase C ◽  
Ventral Tegmental

Dopaminergic neurons of the ventral tegmental area (VTA) have been implicated in the rewarding properties of drugs of abuse and in the etiology of schizophrenia; serotonin modulation of these neurons may play a role in these phenomena. Whole cell patch-in-the-slice recording in rat brain slices was used to investigate modulation of the hyperpolarization-activated cationic current Ih by serotonin in these neurons. Serotonin (50-500 μM) reduced the amplitude of Ih in a concentration-dependent manner; this effect was reversible after prolonged washout of serotonin. This effect was mimicked by the 5-HT2 agonist α-methylserotonin (25 μM) and reversed by the 5-HT2 antagonist ketanserin (25 μM). Serotonin reduced the maximal Ih current and conductance (measured at -130 mV) and caused a negative shift in the voltage dependence of Ih activation. The serotonin-induced reduction in Ih amplitude was antagonized by intracellular administration of the nonspecific protein kinase inhibitor H-7 (75 μM) and the selective protein kinase C inhibitor chelerythrine (25 μM). The protein kinase C activator phorbol 12, 13 diacetate (PDA, 2 μM) reduced Ih amplitude; when PDA and serotonin were applied together, the effect on Ih was less than additive. These data support the conclusion that serotonin reduces Ih in dopaminergic VTA neurons by acting at serotonin 5-HT2 receptors, which activate protein kinase C. This reduction of Ih may be physiologically important, as the selective inhibitor of Ih, ZD7288, significantly increased dopamine inhibition of firing rate of dopaminergic VTA neurons, an effect that we previously demonstrated with serotonin.

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.

CCK activates p90rsk in rat pancreatic acini through protein kinase C

1997 ◽  
Vol 272 (3) ◽  
pp. G401-G407 ◽  
Author(s):  
M. J. Bragado ◽  
A. Dabrowski ◽  
G. E. Groblewski ◽  
J. A. Williams
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Kinase Inhibitor ◽  
Threshold Concentration ◽  
Mitogen Activated Protein Kinase ◽  
Maximal Effect ◽  
Dependent Manner ◽  
Pancreatic Acini ◽  
Kinase C ◽  
Mitogen Activated Protein

The presence of the 90-kDa ribosomal S6 protein kinase (p90(rsk)) in isolated rat pancreatic acini was demonstrated by Western blotting and immunoprecipitation with anti-p90(rsk). Cholecystokinin (CCK) activated p90(rsk) activity in a time- and dose-dependent manner and increased its phosphorylation. The threshold concentration of CCK was 10 pM and the maximal effect was seen at 1 nM. An increase in p90(rsk) was observed 1 min after 1 nM CCK stimulation, reaching a maximum at 10 min, when p90(rsk) activity was increased 5.4-fold. Carbachol and bombesin, but not vasoactive intestinal peptide, also activated p90(rsk). CCK-induced activation of p90(rsk) appears to be mediated by protein kinase C (PKC), since 12-O-tetradecanoylphorbol-13-acetate increased p90(rsk) activity 5.3-fold. GF-109293X, a potent inhibitor of PKC, strongly inhibited CCK-evoked p90(rsk) activity. Treatment of acini with ionomycin or 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid had no effect, indicating that mobilization of intracellular Ca2+ by CCK is not important in p90(rsk) activation. Although there were some quantitative differences in the extent of inhibition, the specific inhibitors [rapamycin, wortmannin, mitogen-activated protein kinase (MAPK) kinase inhibitor PD98059, and GF-109293X] had parallel effects on p90(rsk) and p42(mapk) activities, consistent with a model in which p90(rsk) can be regulated in acini by MAPK.

Protein kinase C–catalyzed phosphorylation of an inhibitory phosphoprotein of myosin phosphatase is involved in human platelet secretion

Blood ◽  
2001 ◽  
Vol 97 (12) ◽  
pp. 3798-3805 ◽  
Author(s):  
Yasuyuki Watanabe ◽  
Masaaki Ito ◽  
Yoshiyuki Kataoka ◽  
Hideo Wada ◽  
Mutsumi Koyama ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Kinase Inhibitor ◽  
Rho Kinase ◽  
Myosin Phosphatase ◽  
Kinase C ◽  
Atp Secretion ◽  
Mlc20 Phosphorylation ◽  
Platelet Secretion

Protein kinase C (PKC)–potentiated inhibitory phosphoprotein of myosin phosphatase (CPI) was detected in human platelets. Like smooth muscle CPI-17, in vitro phosphorylation of platelet CPI by PKC inhibited the activity of myosin phosphatase containing the PP1δ catalytic subunit and the 130-kd myosin-binding subunit (MBS). Treatment of intact platelets with thrombin or the stable thromboxane A2 analog STA2 resulted in increased phosphorylation of both CPI and MBS at Thr-696, whereas phorbol myristate acetate (PMA) and the Ca++ ionophore ionomycin only induced CPI phosphorylation. PMA induced slow adenosine triphosphate (ATP) secretion of fura 2–loaded platelets with no change in cytosolic Ca++. The PMA-induced increase in CPI phosphorylation preceded phosphorylation of 20-kd myosin light chain (MLC20) at Ser-19 and ATP secretion. The PKC inhibitor, GF109203X, inhibited PMA-induced phosphorylation of CPI and MLC20 with similar IC50 values. These findings suggest that the activation of PKC by PMA induces MLC20phosphorylation by inhibiting myosin phosphatase through phosphorylation of CPI. STA2-induced MLC20phosphorylation was also diminished but not abolished by GF109203X, even at high concentrations that completely inhibited STA2-induced CPI phosphorylation. A combination of the Rho-kinase inhibitor Y-27632 and GF109203X led to a further decrease in STA2-induced MLC20 phosphorylation, mainly because of a significant inhibition of MBS phosphorylation at Thr-696. Inhibition of STA2-induced ATP release by Y-27632, GF109203X, or both appeared to correlate with the extent of MLC20 phosphorylation. Thus, CPI phosphorylation by PKC may participate in inhibiting myosin phosphatase, in addition to the Rho-kinase–mediated regulation of myosin phosphatase, during agonist-induced platelet secretion.

Inhibition of protein kinase C-mediated contraction by Rho kinase inhibitor fasudil in rabbit aorta

2004 ◽  
Vol 370 (5) ◽  
pp. 414-422 ◽  
Author(s):  
Erika Shimomura ◽  
Mitsuya Shiraishi ◽  
Takahiro Iwanaga ◽  
Minoru Seto ◽  
Yasuharu Sasaki ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Kinase Inhibitor ◽  
Rho Kinase ◽  
Rabbit Aorta ◽  
Kinase C ◽  
Rho Kinase Inhibitor

Acetylcholine-induced phosphorylation of CPI-17 in rat bronchial smooth muscle: the roles of Rho-kinase and protein kinase C

2005 ◽  
Vol 83 (4) ◽  
pp. 375-381 ◽  
Author(s):  
Hiroyasu Sakai ◽  
Tomona Hirano ◽  
Hisao Takeyama ◽  
Yoshihiko Chiba ◽  
Miwa Misawa
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Dependent Manner ◽  
Rock Inhibitor ◽  
Bronchial Smooth Muscle ◽  
Calphostin C ◽  
Kinase C

It has been demonstrated that CPI-17 provokes an inhibition of myosin light chain phosphatase to increase myosin light chain phosphorylaton and Ca2+ sensitivity during contraction of vascular smooth muscle. However, expression and agonist-mediated regulation of CPI-17 in bronchial smooth muscle have not been documented. Thus, expression and phosphorylation of CPI-17 mediated by PKC and ROCK were investigated using rat bronchial preparations. Acetylcholine (ACh)-induced contraction and Ca2+ sensitization were both attenuated by 10–6 mol Y-27632 /L, a ROCK inhibitor, 10–6 mol calphostin C/L, a PKC inhibitor, and their combination. A PKC activator, PDBu, induced a Ca2+ sensitization in α-toxin-permeabilized bronchial smooth muscle. In this case, the Ca2+ sensitizing effect was significantly inhibited by caphostin C but not by Y-27632. An immunoblot study demonstrated CPI-17 expression in the rat bronchial smooth muscle. Acetylcholine induced a phosphorylation of CPI-17 in a concentration-dependent manner, which was significantly inhibited by Y-27632 and calphostin C. In conclusion, these data suggest that both PKC and ROCK are involved in force development, Ca2+ sensitization, and CPI-17 phosphorylation induced by ACh stimulation in rat bronchial smooth muscle. As such, RhoA/ROCK, PKC/CPI-17, and RhoA/ROCK/CPI pathways may play important roles in the ACh-induced Ca2+ sensitization of bronchial smooth muscle contraction.Key words: CPI-17, bronchial smooth muscle, acetylcholine, ROCK, protein kinase C.

Modulation of the Ca2+ sensitivity of airway smooth muscle cells in murine lung slices

2006 ◽  
Vol 291 (2) ◽  
pp. L208-L221 ◽  
Author(s):  
Yan Bai ◽  
Michael J. Sanderson
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Kinase Inhibitor ◽  
Rho Kinase ◽  
Phosphodiesterase Inhibitor ◽  
Airway Smooth Muscle Cells ◽  
Murine Lung ◽  
Kinase C ◽  
Caffeine Treatment

To investigate the phenomenon of Ca2+ sensitization, we developed a new intact airway and arteriole smooth muscle cell (SMC) “model” by treating murine lung slices with ryanodine-receptor antagonist, ryanodine (50 μM), and caffeine (20 mM). A sustained elevation in intracellular Ca2+ concentration ([Ca2+]i) was induced in both SMC types by the ryanodine-caffeine treatment due to the depletion of internal Ca2+ stores and the stimulation of a persistent influx of Ca2+. Arterioles responded to this sustained increase in [Ca2+]i with a sustained contraction. By contrast, airways responded to sustained high [Ca2+]i with a transient contraction followed by relaxation. Subsequent exposure to methacholine (MCh) induced a sustained concentration-dependent contraction of the airway without a change in the [Ca2+]i. During sustained MCh-induced contraction, Y-27632 (a Rho-kinase inhibitor) and GF-109203X (a protein kinase C inhibitor) induced a concentration-dependent relaxation without changing the [Ca2+]i. The cAMP-elevating agents, forskolin (an adenylyl cyclase activator), IBMX (a phosphodiesterase inhibitor), and caffeine (also acting as a phosphodiesterase inhibitor), exerted similar relaxing effects. These results indicate that 1) ryanodine-caffeine treatment is a valuable tool for investigating the contractile mechanisms of SMCs while avoiding nonspecific effects due to cell permeabilization, 2) in the absence of agonist, sustained high [Ca2+]i has a differential time-dependent effect on the Ca2+ sensitivity of airway and arteriole SMCs, 3) MCh facilitates the contraction of airway SMCs by inducing Ca2+ sensitization via the activation of Rho-kinase and protein kinase C, and 4) cAMP-elevating agents contribute to the relaxation of airway SMCs through Ca2+ desensitization.

Endotoxin-Induced Tissue Factor in Human Monocytes is Dependent upon Protein Kinase C Activation

1993 ◽  
Vol 70 (05) ◽  
pp. 800-806 ◽  
Author(s):  
C Ternisien ◽  
M Ramani ◽  
V Ollivier ◽  
F Khechai ◽  
T Vu ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Tissue Factor ◽  
Factor Ix ◽  
Transcriptional Level ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Human Monocytes ◽  
Kinase C ◽  
Pkc Activation

SummaryTissue factor (TF) is a transmembrane receptor which, in association with factors VII and Vila, activates factor IX and X, thereby activating the coagulation protease cascades. In response to bacterial lipopolysaccharide (LPS) monocytes transcribe, synthesize and express TF on their surface. We investigated whether LPS-induced TF in human monocytes is mediated by protein kinase C (PKC) activation. The PKC agonists phorbol 12- myristate 13-acetate (PMA) and phorbol 12, 13 dibutyrate (PdBu) were both potent inducers of TF in human monocytes, whereas 4 alpha-12, 13 didecanoate (4 a-Pdd) had no such effect. Both LPS- and PMA-induced TF activity were inhibited, in a concentration dependent manner, by three different PKC inhibitors: H7, staurosporine and calphostin C. TF antigen determination confirmed that LPS-induced cell-surface TF protein levels decreased in parallel to TF functional activity under staurosporine treatment. Moreover, Northern blot analysis of total RNA from LPS- or PMA-stimulated monocytes showed a concentration-dependent decrease in TF mRNA levels in response to H7 and staurosporine. The decay rate of LPS-induced TF mRNA evaluated after the arrest of transcription by actinomycin D was not affected by the addition of staurosporine, suggesting that its inhibitory effect occurred at a transcriptional level. We conclude that LPS-induced production of TF and its mRNA by human monocytes are dependent on PKC activation.

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