Interactive role of protein kinase C-delta with rho-kinase in the development of cerebral vasospasm in a canine two-hemorrhage model.
BACKGROUND
We previously reported that protein kinase C (PKC)-delta was initially translocated from the cytosol to the membrane fraction (on day 4), followed by PKC-alpha, with the progression of cerebral vasospasm after subarachnoid hemorrhage (SAH) on day 7. Rho/Rho-kinase pathways have also been proposed to be involved in the vasospasm. Thus we investigated the interactive role of Rho-kinase and PKC in the development of cerebral vasospasm after SAH.


METHODS
The cerebral vasospasm was produced using a 'two-hemorrhage' canine model. The animals were treated with Y-27632, a Rho-kinase inhibitor, and rottlerin, a PKC-delta inhibitor, both injected into the cisterna magna.


RESULTS
Y-27632 inhibited the vasospasm, 20-kDa myosin light chain (MLC20) phosphorylation, and PKC-delta translocation after the second injection of autologous blood on day 4. In contrast, Y-27632 did not affect the vasospasm on day 7. Rottlerin also inhibited the vasospasm on day 4, but had no effect on MLC20 phosphorylation and RhoA translocation. The vasospasm was accompanied with the phosphorylation of caldesmon (CaD), an actin-linked regulatory protein, which was strongly attenuated by Y-27632 and rottlerin. The application of PKC-delta to skinned strips of isolated canine basilar arteries caused a contraction and an increase in CaD phosphorylation.


CONCLUSIONS
The development of cerebral vasospasm after SAH (on day 4) is caused by at least two mechanisms: one involves MLC20 phosphorylation mediated by the inhibition of MLC20 phosphatase by Rho-kinase, and the other CaD phosphorylation mediated by the activation of PKC-delta by Rho-kinase, which results in the alleviation of the inhibition by CaD of myosin Mg2+-ATPase activity.
Obara
Kazuo
K
Department of Cellular and Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka, Japan. obara@ys7.u-shizuoka-ken.ac.jp
Nishizawa
Shigeru
S
Koide
Masayo
M
Nozawa
Kayo
K
Mitate
Ayako
A
Ishikawa
Tomohisa
T
Nakayama
Koichi
K
D000098:Acetophenones / Q000494:pharmacology; D000577:Amides / Q000494:pharmacology; D000818:Animals; D001578:Benzopyrans / Q000494:pharmacology; D002148:Calmodulin-Binding Proteins / Q000378:metabolism; D004195:Disease Models, Animal; D004285:Dogs; D005260:Female; D066298:In Vitro Techniques; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D018994:Myosin Light Chains / Q000378:metabolism; D010766:Phosphorylation; D011493:Protein Kinase C / Q000502:physiology*; D051745:Protein Kinase C-delta; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D021381:Protein Transport; D011725:Pyridines / Q000494:pharmacology; D013345:Subarachnoid Hemorrhage / Q000150:complications*; D014661:Vasoconstriction / Q000187:drug effects; D020301:Vasospasm, Intracranial / Q000209:etiology*; D054460:rho-Associated Kinases
D000098:Acetophenones; D000577:Amides; D001578:Benzopyrans; D002148:Calmodulin-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D018994:Myosin Light Chains; D011725:Pyridines; C108830:Y 27632; C085746:rottlerin; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D011493:Protein Kinase C; D051745:Protein Kinase C-delta