Beta adrenergic overstimulation impaired vascular contractility via actin-cytoskeleton disorganization in rabbit cerebral artery.
OBJECTIVE
Beta adrenergic overstimulation may increase the vascular damage and stroke. However, the underlying mechanisms of beta adrenergic overstimulation in cerebrovascular dysfunctions are not well known. We investigated the possible cerebrovascular dysfunction response to isoproterenol induced beta-adrenergic overstimulation (ISO) in rabbit cerebral arteries (CAs).


METHODS
ISO was induced in six weeks aged male New Zealand white rabbit (0.8-1.0 kg) by 7-days isoproterenol injection (300 μg/kg/day). We investigated the alteration of protein expression in ISO treated CAs using 2DE proteomics and western blot analysis. Systemic properties of 2DE proteomics result were analyzed using bioinformatics software. ROS generation and following DNA damage were assessed to evaluate deteriorative effect of ISO on CAs. Intracellular Ca(2+) level change and vascular contractile response to vasoactive drug, angiotensin II (Ang II), were assessed to evaluate functional alteration of ISO treated CAs. Ang II-induced ROS generation was assessed to evaluated involvement of ROS generation in CA contractility.


RESULTS
Proteomic analysis revealed remarkably decreased expression of cytoskeleton organizing proteins (e.g. actin related protein 1A and 2, α-actin, capping protein Z beta, and vimentin) and anti-oxidative stress proteins (e.g. heat shock protein 9A and stress-induced-phosphoprotein 1) in ISO-CAs. As a cause of dysregulation of actin-cytoskeleton organization, we found decreased level of RhoA and ROCK1, which are major regulators of actin-cytoskeleton organization. As functional consequences of proteomic alteration, we found the decreased transient Ca(2+) efflux and constriction response to angiotensin II and high K(+) in ISO-CAs. ISO also increased basal ROS generation and induced oxidative damage in CA; however, it decreased the Ang II-induced ROS generation rate. These results indicate that ISO disrupted actin cytoskeleton proteome network through down-regulation of RhoA/ROCK1 proteins and increased oxidative damage, which consequently led to contractile dysfunction in CA.
National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University, Busan, Korea.
Hyoung Kyu
HK
Kim
Won Sun
WS
Park
Mohamad
M
Warda
So Youn
SY
Park
Eun A
EA
Ko
Min Hee
MH
Kim
Seung Hun
SH
Jeong
Hye-Jin
HJ
Heo
Tae-Hoon
TH
Choi
Young-Won
YW
Hwang
Sun-Il
SI
Lee
Kyung Soo
KS
Ko
Byoung Doo
BD
Rhee
Nari
N
Kim
Jin
J
Han
D008841:Actin Cytoskeleton / Q000378:metabolism*; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D002536:Cerebral Arteries / Q000187:drug effects* / Q000378:metabolism*; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D011817:Rabbits; D017382:Reactive Oxygen Species / Q000378:metabolism; D054460:rho-Associated Kinases / Q000378:metabolism; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
D017382:Reactive Oxygen Species; D000804:Angiotensin II; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein; D007545:Isoproterenol