Review Article Genetics of Cerebral Vasospasmdownloads.hindawi.com/journals/nri/2013/291895.pdf · muscle contraction of cerebral arteries in mammals [ ]. A ... key signaling mediators

Hindawi Publishing CorporationNeurology Research InternationalVolume 2013 Article ID 291895 11 pageshttpdxdoiorg1011552013291895

Review ArticleGenetics of Cerebral Vasospasm

Travis R Ladner1 Scott L Zuckerman2 and J Mocco2

1 Vanderbilt University School of Medicine Nashville TN 37212 USA2Department of Neurological Surgery Vanderbilt University School of Medicine Nashville TN 37212 USA

Correspondence should be addressed to J Mocco jmoccovanderbiltedu

Received 7 November 2012 Accepted 10 March 2013

Academic Editor William Mack

Copyright copy 2013 Travis R Ladner et alThis is an open access article distributed under theCreativeCommonsAttributionLicensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Cerebral vasospasm (CV) is a major source of morbidity and mortality in aneurysmal subarachnoid hemorrhage (aSAH) It isthought that an inflammatory cascade initiated by extravasated blood products precipitates CV disrupting vascular smoothmusclecell function of major cerebral arteries leading to vasoconstriction Mechanisms of CV and modes of therapy are an active area ofresearch Understanding the genetic basis of CV holds promise for the recognition and treatment for this devastating neurovascularevent In our review we summarize the most recent research involving key areas within the genetics and vasospasm discussion (1)Prognostic role of geneticsmdashrisk stratification based on gene sequencing biomarkers and polymorphisms (2) Signaling pathwaysmdashpinpointing key inflammatory molecules responsible for downstream cellular signaling and altering these mediators to providetherapeutic benefit and (3) Gene therapy and gene deliverymdashusing viral vectors or novel protein delivery methods to overexpressprotective genes in the vasospasm cascade

1 Introduction

Cerebral vasospasm (CV) is the narrowing of the major cere-bral arteries following aneurysmal subarachnoid hemorrhage(aSAH) and is a leading contributor to the morbidity andmortality associated with aSAH The annual incidence ofaSAH in the United States is between 21000 and 33000 peo-ple [1] Of these approximately 67 will develop vasospasm[2 3] In the setting of aSAH CV has a biphasic coursewith an acute and chronic phase The acute phase typicallybegins 3 to 4 hours after hemorrhage with rapid spontaneousresolution In contrast the chronic phase begins 3 to 5days later with maximum narrowing between days 6 and 8resolving after about 14 days [4]

CV can be diagnosed angiographically or clinicallyAngiographic vasospasm refers to the observed narrowing ofcontrast medium in the major cerebral arteries Radiologicmodalities used to diagnose CV include computed tomog-raphy angiography (CTA) magnetic resonance angiography(MRA) and catheter angiography Clinical vasospasm is thesequelae of neurocognitive deficits presumably as a result ofa prolonged ischemic state Both angiographic and clinicalvasospasms can lead to cerebral infarction Angiographic

and clinical vasospasms appear to be distinct phenomenawith aSAH patients presenting with angiographic CV only(43 of patients) both angiographic and clinical CV (33 ofpatients) or none of them (24 of patients) [5]

Although there are many hypotheses on the pathogenesisof CV it still remains a poorly understood phenomenon In1944 Zucker observed that lysed erythrocytes incited smoothmuscle contraction of cerebral arteries in mammals [6] Alater clinical angiographic study by Ecker and Riemenschnei-der in 1951 found that the degree of vasospasm is directlyrelated to the volume of subarachnoid blood observed onhead CTs [7] leading to the use of the Fisher Grade inpredicting vasospasm onset [8]

The inciting event of CV is likely an inflammatoryresponse to extravasated blood products in the subarachnoidspace leading to prolonged and deregulated contraction ofvascular smooth muscle cells (VSMCs) [9] Lysed RBCs insubarachnoid space surrounding the cerebral vasculaturecan generate inflammatory downstream effects that resultin endothelial damage and smooth muscle contraction [10]In particular extracorpuscular oxyhemoglobin is the potentinflammatory compound and has been shown to increase theformation of reactive oxygen species (ROS) decrease nitric

2 Neurology Research International

oxide (NO) concentration increase prostaglandin synthesisand increase lipid peroxidation [9 11ndash13] Such changes inthe vascular equilibrium can lead to the activation of pro-vasospasm signaling pathways and the synthesis of inflam-matory gene products This process occurs in parallel to thedelayed cerebral ischemia (DCI) resulting frommicrothrom-boses and cortical spreading ischemia [14 15]

2 Genetics in CV

Whilemuchwork has been done to characterize the signalingpathways implicated in CV the field still lacks a definitiveexplanatory model with robust predictability and therapeutictargets Several presumptive targets have been proposed withonly modest gains For example clazosentan an endothelinreceptor antagonist has shown great attenuation of angio-graphic vasospasm in preclinical and clinical studies butno improvement in neurological outcomes [16] In contrastnimodipine a calcium channel blocker improves func-tional outcomes without a parallel reduction in angiographicvasospasm [17] However the field of genetics offers a newinsight

An active area of research is the exploration of thegenetic basis for CV which has previously been supported bypopulation studies [18] New advances in molecular geneticshave revealed several genes whose products are presumptivemediators of CV and genetic polymorphisms that portendincreased CV risk andor poorer outcomes Understandingthe genetic mechanism of disease generation may provideinsight into novel therapeutic avenues In this review we willsummarize the most recent research in the following areasregarding genetics and CV (1) prognostic role of genetics (2)key signaling mediators involved and (3) gene therapy andgene delivery

21 Prognostic Factors Stratifying risk based on next gen-eration sequencing is gradually becoming integrated intomedical practice [31] In cardiovascularmedicine indicationson the use of drugs such as clopidogrel warfarin and statinshave already been made based on the patientrsquos genotype[32ndash34] Genetic screening of family members of patientsdiagnosed with familial hypercholesterolemia is currentlyrecommended in the UK [35]

Genetic risk stratification for CV holds great potentialClose family members of patients with aneurysms may bescreened for their own susceptibility for aneurysm formationand rupture Genomic biomarkersmay also be used to stratifySAH patients for more intensive monitoring according tovasospasm risk as well as informing medication administra-tion

Genomewide and other gene association studies haveidentified several genes that may play a larger role in develop-ing quick and inexpensive screening protocols in SAH Thisrepresents an update on a genetics review by Ducruet andcolleagues [36] with attention to recent discoveries reportedin the literatureThe following is a summary of genetic mark-ers associated with SAH and CV with evidence for diseasemechanisms as well as implicated polymorphisms (Table 1)

211 Catechol-O-methyltransferase (COMT) Cate-chol-a-mi-nes have been implicated in the development of acuteCV following SAH [37 38] COMT a key enzyme in thedegradation of catecholamines has been shown to play a rolein acute CV A rat model has shown increased expression ofCOMT and catecholamines following SAH induction [39] Astudy of 167 Chinese Han SAH patients showed that patientswith the COMT-A allele AA genotype were more likelyto develop acute CV [40] This polymorphism may be abiomarker for predicting poor outcomes in patients withaneurysms that may later rupture

212 Endothelial Nitric Oxide Synthase (eNOS) GeneEndothelial nitric oxide synthase (eNOS) gene which isfound on chromosome 7q35 plays an important role in CVand other cardiovascular diseases [41] eNOS is present inthe endothelium of the major cerebral arteries and producesnitric oxide (NO) a potent vasodilator Constitutive levelsof NO inhibit platelet aggregation vascular smooth muscleproliferation and inflammation [9 23 42ndash44] Perivascularoxyhemoglobin released after SAH scavenges NO generatedby eNOS decreasing NO-mediated vasorelaxation andcontributing to the onset of vasospasm [45ndash47]

Clinically decreased levels of NO in the CSF have beenreported in aSAH patients Overexpression of the eNOSgene has been shown to be vasoprotective in humans andcanines in the setting of SAH [48 49] Polymorphisms of theeNOS genes are linked to intracranial aneurysm formation[50 51] and coronary vasospasm [52] Genetic associationstudies have shown that eNOS 7-786 gene SNPs predisposeaSAH patients for vasospasm [19ndash23] However the variousfindings are contradictory showing either an effect withthe T allele C allele or no clear association This apparentdiscrepancy is likely attributable to the heterogeneity ofvasospasm definition as well as the complex regulation of theeNOS gene

The activity of eNOS is tightly regulated at manystages including transcription substrate availability cofac-tors protein-protein interactions posttranslationalmodifica-tions and dimerization [59 60] The literature is mixed onwhether eNOS activity is increased [61] decreased [62] orunchanged [63ndash66] following SAH Further it is still unclearwhat role SAH plays in the phosphorylation of eNOS [66]

eNOS is physiologically a homodimer but under patho-logical conditions decouples and forms a ferrous-dioxygencomplex which has a tendency to form superoxide radicalsinstead of NO [67] Recent studies by Sabri and colleagueshave shown that SAH leads to increased phosphorylationof eNOS on Ser1177 and subsequent uncoupling whichdecreases NO availability while simultaneously increasingthe production of superoxide Superoxide may further reactwith remaining NO to form peroxynitrite which continuesto deplete residual NO [61] While it is known that simvas-tatin can mitigate vasospasm [63 68] recent work suggeststhat simvastatin may work by recoupling eNOS to increaseNO production and decrease the production of superoxide[61] This may further explain its mechanism of attenuatingvasospasm clinically and in other animal models [63 64]

Neurology Research International 3

Table 1 Summary of prognostic genes in cerebral vasospasm

Gene Reference 119873 FindingeNOS [19] 141 T-786C promoter rarr clinicalangiographic andor TCD vasospasmeNOS [20] 51 T-786C SNP rarr symptomaticasymptomatic angiographic vasospasmeNOS [21] 136 No relationshipeNOS [22] 347 T-786C SNP rarr angiographic vasospasmeNOS [23] 77 T-786C SNP rarr angiographic vasospasmHp [24] 32 Hp 2 allele rarr angiographic andor TCD vasospasmPAI-1 [25] 126 4G allele rarr DCI and poor 3-month GOSPAI-1 [26] 183 No relationship bw allele and 1-year GOS-EApoE [27] 206 ApoE4 allele rarr poor GOSApoE [28] 101 minus219T rarr clinical and TCD vasospasmRyR1 [29] 46 GT c6178GrarrT rarr symptomatic vasospasmCBS [30] 87 699CT and TT rarr angiographic vasospasm but no increase in delayed cerebral ischemia 1080TT rarr DCI

Another recent study showed that preconditioning (PC)of mice in hypoxic chambers prior to induction of SAHselectively increases the expression and activity of eNOSincreasing NO levels and reducing vasospasm [66] Theseresults suggest that PC-induced vasoprotection is mediatedby upregulation of eNOS In addition decreased NO avail-ability with no change in eNOS activity was observed inSAH which may also support the pathologic uncouplinghypothesis

213 Haptoglobin Haptoglobin (Hp) is a serum proteinproduced primarily by hepatocytes [69] that binds to freehemoglobin released by lysed erythrocytes [70] The boundcomplex is taken up by macrophages through the CD163receptor presumably reducing extracorpuscular hemoglobintoxicity [71] It is composed of an alpha subunit and a betasubunit which are encoded by the haptoglobin alpha geneand haptoglobin beta gene respectively The gene complex isfound on human chromosome 16q22 [72]

TheHp gene exists in 2 alleles in humans and 3 genotypesare possible Hp 1-1 Hp 2-2 or Hp 2-2 The Hp 1 product is alinear dimer the Hp 2-1 product is a linear polymer and theHp 2-2 product is a cyclical polymer [73 74]These structuraldifferences confer different binding affinities with greaterbinding and clearing of hemoglobin in Hp 1-1 individualsand weaker binding and clearance in Hp 2-2 individuals[45 75] As a result the Hp 2-2 allele is thought to bemore proinflammatory than the Hp 1-1 allele leading toincreased inflammation immune response oxidation andvasoconstriction [9 47]

As such the Hp 2-2 allele may be a mediator of CV aswell The Hp gene has been shown to be upregulated in acanine model of CV [76] A study of 32 Fisher Grade 3 SAHpatients conducted in 2006 showed that individuals with theHp 2 allele had greater likelihood than Hp 1 individuals ofdeveloping vasospasm [24] Clinically the allelic distributionof Hp in Western patients roughly corresponds to the preva-lence of CV in Western SAH patients [5 77] In recent yearsthe Hp 2-2 mouse has been investigated as a novel animalmodel for CV and its treatment [78 79]Mice with theHp 2-2

genotype display greater arterial narrowing and neurologicaldeficits compared toHp 1-1mice following experimental SAH[47]

214 Plasminogen Activator Inhibitor-1 (PAI-1) PAI-1 is aprotein encoded by the SERPINEI gene found on the 7q213-q22 chromosome [80] It is antifibrinolytic functioning asthe principal inhibitor of tissue plasminogen activator andurokinase which themselves activate plasmin A commonpolymorphism is the 4G5G SNP on the promoter region[81] The 4G allele has been previously associated withhigher plasma concentrations of PAI-1 in the acute settingand poorer survival after trauma [82] as well as increasedPAI-1 activity in myocardial infarction [83] PAI-1 has alsobeen investigated in the setting of SAH for a possible linkto thrombosis-related DCI thought to contribute to theneurological deficits resulting from CV [14] A study of 126aSAH patients in 2004 found that the presence of the 4Gallele in the 4G5Gpromoter SNP is associatedwith increasedrisk for cerebral ischemia andpoorer 3-monthGOSoutcomesrelative to the 5G allele [25] However another study of 183aSAHpatients in 2009 found no association between the PAI-1 SNP and poor outcomes on the 1-year GOS-E scale [26]Given the multifactorial nature of vasospasm more workmust be done to characterize this apparent discrepancy

215 Apolipoprotein E (ApoE) ApoE a polymorphic proteinencoded by the ApoE gene is associated with plasma lipopro-teins and is involved in lipid transport and metabolism inthe central nervous system [84] ApoE has been studiedextensively in the literature for its significance to cerebrovas-cular disease Three common alleles have been reported inhumans (1205762 1205763 and 1205764) on the 19p13 chromosome encoding3 different isoforms (ApoE2 ApoE3 and ApoE4) [85] The1205764 allele predisposes patients to poor neurological outcomesin CV traumatic brain injury and ischemic stroke [27 86ndash88] However the purported role of this allele in vasospasmfollowing aSAH is still unclear While this polymorphismdoes not appear to play a role in generating vasospasm itseems to inhibit normal neuronal plasma membrane repair


following cerebral ischemia ostensibly worsening outcomesfor the patients that do end up developing vasospasm [36]

Within the past decade the promoter region of ApoEhas come under more scrutiny for its role in CV after SAHPolymorphisms in the promoter region have previously beenassociated with poorer outcomes in traumatic brain injuryA study in 2003 found that carriers of the G-219T allele hadmore unfavorable GOS functional scores [89] Another studyreported that in e4 carriers the 491AA SNP contributed topoor outcomes in traumatic brain injury [90] A study of 101SAH patients in China in 2010 showed that patients carryingtheminus219T allele had an increased risk of CV [28]This effect ispossibly mediated through decreased transcriptional activityof ApoE which decreases its protective effect in the setting ofinflammation [28]

A recent study of ApoE knockout mice [91] observedenhanced vasoconstriction in response to endothelin-1 avasoconstrictive compound associated with CV [92] Admin-istration of cilostazol was reported to decrease endothelialdysfunction in knockout mice which likely increases eNOSphosphorylation [93] This suggests that ApoE may play avasoprotective role in CV and that underexpression of thegene may be overcome with medication for patients withnormal eNOS expression in the setting of SAH

216 Ryanodine Ryanodine receptors (RyRs) are a family ofCa2+ intracellular calcium channels thatmediate the calcium-induced calcium release (CICR) There are three subtypes(RyR1 RyR2 and RyR3) which are all present in vascularsmooth muscle [94 95] Activation of these receptors facil-itates Ca2+ sparks which promote vasorelaxation throughhyperpolarizing VSMCs [96ndash98] RyRs are involved in theregulation of cerebral artery luminal diameter [99 100]and recent evidence indicates that RyRs may play a rolein the pathogenesis of vasospasm after SAH Koide andcolleagues found a 50 reduction in Ca2+ spark activitycoupled with a 65 reduction in RyR2 expression followinginduced SAH in rabbits [96] These changes appear to comefrom a combination of reduced RyR2 expression as well asincreased FKBP126 expression a stabilizer of RyR2 channelsClinically polymorphisms in genes encodingRyRs are relatedto vasospasm onset A 2011 study of 46 patients in Germanyrevealed that SAH patients who were heterozygous for thec6178GgtT polymorphism of the RyR1 gene were more likelyto develop symptomatic vasospasm [29]

217 Cystathionine 120573-Synthase Cystathionine 120573-synthase(CBS) is an enzyme that converts homocysteine and serine toform cystathionine releasing H

2S in the process [101] H

2S

is a vasodilator and neuromodulator and is known to func-tion in the cerebral circulation although the nature of itsinteraction warrants further study [30 102 103] CBS is thepredominant source of H

2S in the brain and therefore may

play a role in cerebrovascular disease A study of 87 aSAHpatients found that those with the 699CT and TT (gain offunction) genotypes had increased angiographic vasospasmbut no increase in delayed cerebral ischemia [30] Delayedcerebral ischemia was more frequent in 1080TT (decline of

function) populationsThis study suggests thatH2S-mediated

signaling is neuroprotective in aSAH and this protectionmaynot be dependent on vasoprotection

More workmust be done to characterize these prognosticgenes and generate more consistent findings on their rolein vasospasm Differences in study designs sample sizesand vasospasm-monitoring modalities must be reconciledfor more definitive explanations However these remain themost studied genes and may therefore play a role in futurestratification of SAH patients

22 Signaling Pathways Inflammatory molecules generatedfrom the breakdown of blood products following SAH inciteseveral known cascades of cellular signaling enzymes Inparticular compounds such as endothelin-1 oxyhemoglobinbilirubin oxidation products (BOXes) and ROS activatecytokine and cellular signaling pathways [9 104 105] Thesecan lead to the alteration of expression of CV-related genesthe mechanisms of which are still currently being investi-gated Preliminary studies have shown that alteration of thesepathways may provide therapeutic benefit The following is asummary of 3 important known pathways in CV

221 RasMAPK TheMAPK signaling pathway is importantin the generation of vasospasm [106] It is hypothesizedthat spasmogens when released from lysed blood cellssurrounding vascular tissue lead to the sequential activationof phospholipase C (PLC) inositol-145-trisphosphate (IP

3)

and diacylglycerol (DAG) This pathway mobilizes Ca2+ andactivates protein kinase C (PKC) which together activateprotein tyrosine kinase (TK) TK phosphorylates Ras to formthe GTP-bound activated form of Ras which is associatedwith cell cycle regulation cell adhesion and migration [107]ROS as those generated following SAH have also beenassociated with Ras activation [108]

Ras has been shown to be activated in a rabbit modelof SAH peaking at day 3 [107] GTP-bound (activated) Rasinteracts with Raf-1 to phosphorylate downstream effectorssuch as extracellular signal-regulated kinase (ERK) As suchinhibition of the Ras-ERK pathway is associated with areduction in vasospasm in rabbit and canine models of SAH[107 109 110]

MAPK is associated with vasoconstriction impairedvasorelaxation tissue proliferation apoptosis and inflam-mation [106 111] An in vitro model using human vascularsmooth muscle cells found that inhibition of p38 MAPKresulted in decreased vasospasm and cytokine production[112] It is hypothesized that caldesmon and calponin whichare substrates for MAPK are associated with vasoconstric-tion but the exact interaction has not yet been determined[106 113] These proteins are inhibitors of Ca2+-dependentsmoothmuscle contraction and inhibition of thembyMAPKmay lead to sustained vascular smooth muscle contraction[106]

222 JAKSTAT Signaling The JAKSTAT signaling pathwayis an importantmediator of downstream cytokine and growthfactor activity [114] and may be involved in the pathogenesis


Table 2 Summary of preclinical in vivo gene therapy experiments

Gene Reference Method Organism Expression Effect120573-galactosidase [53] Adenovirus Canine Leptomeninges ependyma and BA adventitia mdashCGRP [54] Adenovirus Rabbit CSF BA adventitia and perivascular tissue Attenuation of vasoconstrictionHMOX [55] Adenovirus Rat HO-1 mRNA and protein in BA adventitia Attenuation of vasoconstrictioneNOS [49] Adenovirus Canine BA adventitia Attenuation of vasoconstrictionSuperoxide dismutase [56] Adenovirus Rabbit BA adventitia Attenuation of vasoconstrictionCGRP [57] Protein Rat mdash Attenuation of vasoconstrictionHMOX [58] Arginine Rat All layers of BA Attenuation of vasoconstriction

of CV Cytokines such as IL-6 are known to be elevated inSAHpatients and are also known activators of JAKs JAK1 hasbeen shown to be activated in a rat model of SAH followingproduction of IL-6 [115] JAK2 has also been shown to beactivated in a rabbit model of SAH [116] Activated JAKssubsequently phosphorylate STAT proteins STAT proteinshave been shown to be activated in the basilar artery in a ratmodel of SAHwith STAT3 expressed in the intima andmediaand STAT1 expressed in the adventitia [115] While STAT3is activated in response to cytokines STAT1 is activated bythe free radicals generated by oxyhemoglobin metabolismfollowing SAH [117]

JAK2STAT3 signaling is associated with the expressionof the apoptotic genes bcl-2 and bcl-xL in the intima of thebasilar arteries in rabbits [116] JAK1STAT3 signaling in ratsupregulates the inflammatory COX-2 protein in the intima[115] These early gene products may mediate the generationof vasospasm as fibrosis of the cerebral arteries is associatedwith vasospasm following SAH [118] Endothelial cell deathpromotes thrombosis and decreases vasodilator expression[119ndash121] COX-2 products including prostaglandins andthromboxanes are known to lead to endothelial dysfunctionthrough endothelial-dependent contractions [122] Inflam-matory changes in the adventitia may result in decreasedvessel compliance and may contribute to the vessel stiffnessobserved in CV [120] Taken together these findings suggestthat the JAKSTAT pathway may be an important mediatorof vasospasm

223 RhoRho-Kinase Rho proteins are small G proteinsthat are commonly expressed in mammals [123] Rho-kinasethe effector of Rho plays an important role in the car-diovascular system through its interaction with the myosinlight chain (MLC) in VSMC contractions Rho-kinase phos-phorylates and inhibits myosin light chain phosphatase andtherefore increases contractility [124] Rho-kinase also phos-phorylates myosin light chain directly generating sustainedcontraction in a similar manner as the Ca2+calmodulin-dependent MLC kinase pathway [125] Rho-kinase has beenshown to be involved in the pathogenesis of both coronaryand cerebral vasospasm [124 126ndash131] Oxyhemoglobin fromSAH activates RhoRho-kinase signaling [127] In addi-tion the RhoRho-kinase pathway decreases NO productionthrough the production of cyclophilin A (CyPA) whichdecreases eNOS expression [132] CyPA itself stimulatesERK12 Akt and JAK in VSMCs which contributes to

increased ROS production [133 134] Rho-kinase is alsoknown to play a role in vascular smooth muscle throughincreasing vascular smooth muscle proliferation ROS pro-duction inflammation and endothelial damage [123 134]Fasudil an inhibitor of Rho-kinase has shown some benefitin treating vasospasm in SAH patients [135]

23 Gene Therapy and Delivery We summarize the currentstatus of gene therapy in CV (Table 2)Within the past decadeviral vector-mediated gene therapy has been explored in thecontext of vasospasm and other vascular diseases [136 137]In a proof-of-concept experiment reported in 1997 Muhonenand colleagues demonstrated that 120573-galactosidase could betransferred to cerebral blood vessels and surrounding tissueduring vasospasm using a virus vector [53] In 2002 Ono andcolleagues showed that the HMOX1 gene can be transferredto the rat basilar artery adventitia through adenovirus usingtranscisternal injection Overexpression of heme oxygenase-1 attenuated vasospasm in this model This was associatedwith increased heme oxygenase-1 mRNA and activity withincreased basilar artery diameter and CBF [55 138] In thelast decade thismethod has shown efficacy in preclinical SAHmodels using genes such as calcitonin gene-related peptide(CGRP) [54] eNOS [49] and superoxide dismutase [56]There are no published clinicalmodels of such therapy to datein CVHowever overexpression of the SERCA2a gene by viraltransfer has shown success in improving outcomes in heartfailure patients [139ndash141] Intramuscular injection of VEGF-carrying adenovirus has improved peripheral artery occlusivedisease and coronary artery disease in clinical trials [137 142]

231 Challenges Despite the promise gene therapy holdsthere are several challenges to the translation of preclinicalprotocols to humans in the setting of CV [136] The routeof administration is typically through the cisterna magnawhich requires more invasive procedures in critically illpatients however external ventricular drains may provideappropriate CSF access It is difficult to ensure adequate andaccurate tissue distribution especially to the endotheliumIn addition humans have increased body weight relative tosmall laboratory animals Therefore greater loads of gene-carrying viruses will be required As CV is a polygenicdisorder single gene therapy alone may not be sufficient Itmay be more difficult to express genes within deeper layersof blood vessels with perivascular administration Perhapsthe development of endovascular administrationwith vectors


with enhanced transfer efficiency may be a solution Therehave also been problems with expressed genes remainingfunctional for only short periods of time perhaps fromweeksto months However given the relatively short time course ofvasospasm this may not matter as much

Safety concerns such as inflammation viral cytotoxicityand random viral DNA integration into host cells still persist[136]These eventsmay be especially problematic in CV as anincrease in inflammationmay exacerbate existing vasospasmand such responses have been shown in adenovirus genetherapy [55] Fortunately in human trials of angiogenesisgene transfer for vascular disease no increases in tumorsretinopathy kidney failure or cardiovascular endpoints havebeen reported [142]

232 Alternatives There are other potential approaches totargeting CV-related genes which involve delivering geneproducts to vascular tissue Two recent developments aresummarized below

233 Arginine-Conjugated Gene Delivery Presumptive geneproducts can be conjugated with 10ndash20 amino acid polypep-tides and delivered into somatic cells [143] This form ofprotein therapy can be used for therapeutic overexpression ofgenes in CV In 2011 Ogawa and colleagues demonstrated thatHMOX1 can be conjugated with an 11 arginine polypeptideand introduced by transcisternal injection in a rat modelThey found that this method transduced the HMOX1 geneinto all layers of the basilar artery and was vasoprotectivein an experimental SAH model [143] Such a method maybe applicable to transduction of other vasoprotective genespreviously discussed in order to mitigate CV Howeverconcerns such as short time course of action the need forcontinuous administration imprecise delivery and the needfor large doses may make this less practical In addition thisstudy reported no neurological differences in treated rats

234 Intranasal Protein Delivery Advances in drug deliveryhave made targeted therapy even more attractive Crossingthe blood-brain barrier (BBB) has been a historical chal-lenge in neurotherapeutics In addition decreased cerebralblood flow (CBF) in the perivasospasm period decreasesthe delivery of intra-arterial administered drugs In 2011Ogawa and colleagues demonstrated that intranasal deliveryof calcitonin gene-related protein (CGRP) can be an effectiveand minimally invasive way of bypassing the BBB [58]This study performed in a rat model of SAH attenuatedvasospasmof the basilar artery aswell as neurological deficitsMore work will need to be done to see if this method isamenable to other known medications and gene products

3 Conclusion

Within the past decade there has been increased knowledgein the genetic basis of CV along with refinements in genetherapy Advances in genetic technology could add geneticscreening and gene delivery to the armamentarium of futureproviders caring for SAH patients While further study will

be required to translate the available knowledge into clinicalpractice the field of genetics holds great promise for themanagement of cerebral vasospasm

Conflict of Interests

The authors report no conflict of interests concerning thematerials or methods used in this study or the findingsspecified in this paper

References

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[2] N W C Dorsch and M T King ldquoA review of cerebralvasospasm in aneurysmal subarachnoid haemorrhage Part Iincidence and effectsrdquo Journal of Clinical Neuroscience vol 1no 1 pp 19ndash26 1994

[3] N F Kassell T Sasaki A R T Colohan andGNazar ldquoCerebralvasospasm following aneurysmal subarachnoid hemorrhagerdquoStroke vol 16 no 4 pp 562ndash572 1985

[4] B Weir M Grace J Hansen and C Rothberg ldquoTime course ofvasospasm in manrdquo Journal of Neurosurgery vol 48 no 2 pp173ndash178 1978

[5] N W C Dorsch ldquoCerebral arterial spasm-a clinical reviewrdquoBritish Journal of Neurosurgery vol 9 no 3 pp 403ndash412 1995

[6] M B Zucker ldquoA study of the substances in blood serum andplatelets which stimulate smooth musclerdquo American Journal ofPhysiology vol 142 no 1 pp 12ndash26 1944

[7] A Ecker and P A Riemenschneider ldquoArteriographic demon-stration of spasm of the intracranial arteries with special ref-erence to saccular arterial aneurysmsrdquo Journal of neurosurgeryvol 8 no 6 pp 660ndash667 1951

[8] C M Fisher J P Kistler and J M Davis ldquoRelation ofcerebral vasospasm to subarachnoid hemorrhage visualized bycomputerized tomographic scanningrdquo Neurosurgery vol 6 no1 pp 1ndash9 1980

[9] K L Chaichana G Pradilla J Huang and R J TamargoldquoRole of inflammation (leukocyte-endothelial cell interactions)in vasospasm after subarachnoid hemorrhagerdquo World Neuro-surgery vol 73 no 1 pp 22ndash41 2010

[10] M Zimmermann and V Seifert ldquoEndothelin and subarachnoidhemorrhage an overviewrdquoNeurosurgery vol 43 no 4 pp 863ndash876 1998

[11] DH Edwards TMGriffithH C Ryley andAHHendersonldquoHaptoglobin-haemoglobin complex in human plasma inhibitsendothelium dependent relaxation evidence that endotheliumderived relaxing factor acts as a local autocoidrdquo CardiovascularResearch vol 20 no 8 pp 549ndash556 1986

[12] S A Saeed N Ahmad and S Ahmed ldquoDual inhibition ofcyclooxygenase and lipoxygenase by human haptoglobin itspolymorphism and relation to hemoglobin bindingrdquo Biochem-ical and Biophysical Research Communications vol 353 no 4pp 915ndash920 2007

[13] A Agil C J Fuller and I Jialal ldquoSusceptibility of plasma toferrous ironhydrogen peroxide-mediated oxidation demon-stration of a possible Fenton reactionrdquo Clinical Chemistry vol41 no 2 pp 220ndash225 1995

[14] M D I Vergouwen M Vermeulen B A Coert E S G Stroesand Y B W E M Roos ldquoMicrothrombosis after aneurys-mal subarachnoid hemorrhage an additional explanation for


delayed cerebral ischemiardquo Journal of Cerebral Blood Flow andMetabolism vol 28 no 11 pp 1761ndash1770 2008

[15] J P Dreier J Woitzik M Fabricius et al ldquoDelayed ischaemicneurological deficits after subarachnoid haemorrhage are asso-ciated with clusters of spreading depolarizationsrdquo Brain vol129 no 12 pp 3224ndash3237 2006

[16] R L Macdonald R T Higashida E Keller et al ldquoRandomizedtrial of clazosentan in patients with aneurysmal subarachnoidhemorrhage undergoing endovascular coilingrdquo Stroke vol 43no 6 pp 1463ndash1469 2012

[17] F G Barker II and C S Ogilvy ldquoEfficacy of prophylacticnimodipine for delayed ischemic deficit after subarachnoidhemorrhage a metaanalysisrdquo Journal of Neurosurgery vol 84no 3 pp 405ndash414 1996

[18] J Mocco E R Ransom R J Komotar et al ldquoRacial differencesin cerebral vasospasm a systematic review of the literaturerdquoNeurosurgery vol 58 no 2 pp 305ndash312 2006

[19] V G Khurana Y R Sohni W I Mangrum et al ldquoEndothelialnitric oxide synthase gene polymorphisms predict suscepti-bility to aneurysmal subarachnoid hemorrhage and cerebralvasospasmrdquo Journal of Cerebral Blood Flow andMetabolism vol24 no 3 pp 291ndash297 2004

[20] V G Khurana D J Fox I Meissner F B Meyer and R FSpetzler ldquoUpdate on evidence for a genetic predisposition tocerebral vasospasmrdquo Neurosurgical Focus vol 21 no 3 articleE3 2006

[21] M K SongM K Kim T S Kim et al ldquoEndothelial nitric oxidegene T-786C polymorphism and subarachnoid hemorrhage inKorean populationrdquo Journal of Korean Medical Science vol 21no 5 pp 922ndash926 2006

[22] N U Ko P Rajendran H Kim et al ldquoEndothelial nitricoxide synthase polymorphism (-786TrarrC) and increased riskof angiographic vasospasm after aneurysmal subarachnoidhemorrhagerdquo Stroke vol 39 no 4 pp 1103ndash1108 2008

[23] R M Starke G H Kim R J Komotar et al ldquoEndothelialnitric oxide synthase gene single-nucleotide polymorphismpredicts cerebral vasospasm after aneurysmal subarachnoidhemorrhagerdquo Journal of Cerebral Blood Flow and Metabolismvol 28 no 6 pp 1204ndash1211 2008

[24] M Borsody A Burke W Coplin R Miller-Lotan and ALevy ldquoHaptoglobin and the development of cerebral arteryvasospasm after subarachnoid hemorrhagerdquoNeurology vol 66no 5 pp 634ndash640 2006

[25] M D I Vergouwen C J M Frijns Y B W E M Roos G JE Rinkel F Baas and M Vermeulen ldquoPlasminogen activatorinhibitor-1 4G allele in the 4G5G promoter polymorphismincreases the occurrence of cerebral ischemia after aneurysmalsubarachnoid hemorrhagerdquo Stroke vol 35 no 6 pp 1280ndash12832004

[26] C Ladenvall L Csajbok K Nylen K Jood B Nellgard andC Jern ldquoAssociation between factor XIII single nucleotidepolymorphisms and aneurysmal subarachnoid hemorrhageclinical articlerdquo Journal of Neurosurgery vol 110 no 3 pp 475ndash481 2009

[27] M J Gallek Y P Conley P R Sherwood M B Horowitz AKassam and S A Alexander ldquoAPOE genotype and functionaloutcome following aneurysmal subarachnoid hemorrhagerdquoBiological Research for Nursing vol 10 no 3 pp 205ndash212 2009

[28] H T Wu J Ruan X D Zhang H J Xia Y Jiang and X CSun ldquoAssociation of promoter polymorphism of apolipoproteine gene with cerebral vasospasm after spontaneous SAHrdquo BrainResearch vol 1362 pp 112ndash116 2010

[29] H Rueffert A Gumplinger C Renner et al ldquoSearch for geneticvariants in the ryanodine receptor 1 gene in patients withsymptomatic cerebral vasospasm after aneurysmal subarach-noid hemorrhagerdquoNeurocritical Care vol 15 no 3 pp 410ndash4152011

[30] B T Grobelny A F Ducruet P A Derosa et al ldquoGain-of-function polymorphisms of cystathionine 120573-synthase anddelayed cerebral ischemia following aneurysmal subarachnoidhemorrhage clinical articlerdquo Journal of Neurosurgery vol 115no 1 pp 101ndash107 2011

[31] J S Ware A M Roberts and S A Cook ldquoNext generationsequencing for clinical diagnostics and personalised medicineimplications for the next generation cardiologistrdquoHeart vol 98no 4 pp 276ndash281 2012

[32] F Sofi B Giusti R Marcucci A M Gori R Abbate andG F Gensini ldquoCytochrome P450 2C19lowast2 polymorphism andcardiovascular recurrences in patients taking clopidogrel ameta-analysisrdquo Pharmacogenomics Journal vol 11 no 3 pp199ndash206 2011

[33] J L Anderson B D Horne S M Stevens et al ldquoRandomizedtrial of genotype-guided versus standard warfarin dosing inpatients initiating oral anticoagulationrdquoCirculation vol 116 no22 pp 2563ndash2570 2007

[34] L R Brunham P J Lansberg L Zhang et al ldquoDifferential effectof the rs4149056 variant in SLCO1B1 on myopathy associatedwith simvastatin and atorvastatinrdquo Pharmacogenomics Journalvol 12 no 3 pp 233ndash237 2012

[35] RM Ned and E J G Sijbrands ldquoCascade screening for familialhypercholesterolemia (FH)rdquo PLoS Currents vol 3 2011

[36] A F Ducruet P R Gigante Z L Hickman et al ldquoGeneticdeterminants of cerebral vasospasm delayed cerebral ischemiaand outcome after aneurysmal subarachnoid hemorrhagerdquoJournal of Cerebral Blood Flow and Metabolism vol 30 no 4pp 676ndash688 2010

[37] A Dilraj J H Botha V Rambiritch R Miller J R VanDellen and J HWood ldquoLevels of catecholamine in plasma andcerebrospinal fluid in aneurysmal subarachnoid hemorrhagerdquoNeurosurgery vol 31 no 1 pp 42ndash51 1992

[38] S Naredi G Lambert P Friberg et al ldquoSympathetic activationand inflammatory response in patients with subarachnoidhaemorrhagerdquo Intensive Care Medicine vol 32 no 12 pp 1955ndash1961 2006

[39] Z He X Sun Z Guo and J H Zhang ldquoExpression and roleof COMT in a rat subarachnoid hemorrhage modelrdquo ActaNeurochirurgica vol 110 part 1 pp 181ndash187 2011

[40] ZHe X Sun ZGuo and JH Zhang ldquoThe correlation betweenCOMT gene polymorphism and early cerebral vasospasm aftersubarachnoid hemorrhagerdquo Acta Neurochirurgica vol 110 no1 pp 233ndash238 2011

[41] P A Marsden H H Heng S W Scherer et al ldquoStruc-ture and chromosomal localization of the human constitutiveendothelial nitric oxide synthase generdquoThe Journal of BiologicalChemistry vol 268 no 23 pp 17478ndash17488 1993

[42] M Y Tseng M Czosnyka H Richards J D Pickard andP J Kirkpatrick ldquoEffects of acute treatment with pravastatinon cerebral vasospasm autoregulation and delayed ischemicdeficits after aneurysmal subarachnoid hemorrhage a phase IIrandomized placebo-controlled trialrdquo Stroke vol 36 no 8 pp1627ndash1632 2005

[43] S Moncada R M J Palmer and E A Higgs ldquoNitric oxidephysiology pathophysiology and pharmacologyrdquo Pharmaco-logical Reviews vol 43 no 2 pp 109ndash142 1991


[44] S Moncada and E A Higgs ldquoThe discovery of nitric oxide andits role in vascular biologyrdquoBritish Journal of Pharmacology vol147 supplement 1 pp S193ndashS201 2006

[45] I Azarov X He A Jeffers et al ldquoRate of nitric oxide scavengingby hemoglobin bound to haptoglobinrdquo Nitric Oxide vol 18 no4 pp 296ndash302 2008

[46] S Nishizawa and I Laher ldquoSignaling mechanisms in cerebralvasospasmrdquoTrends in CardiovascularMedicine vol 15 no 1 pp24ndash34 2005

[47] K L Chaichana A P Levy R Miller-Lotan S Shakurand R J Tamargo ldquoHaptoglobin 2-2 genotype determineschronic vasospasm after experimental subarachnoid hemor-rhagerdquo Stroke vol 38 no 12 pp 3266ndash3271 2007

[48] V G Khurana L A Smith D A Weiler et al ldquoAdenovirus-mediated gene transfer to human cerebral arteriesrdquo Journal ofCerebral Blood Flow and Metabolism vol 20 no 9 pp 1360ndash1371 2000

[49] V G Khurana L A Smith T A Baker D Eguchi T OrsquoBrienand Z S Katusic ldquoProtective vasomotor effects of in vivorecombinant endothelial nitric oxide synthase gene expressionin a canine model of cerebral vasospasmrdquo Stroke vol 33 no 3pp 782ndash789 2002

[50] V G Khurana Y R Sohni W I Mangrum et al ldquoEndothelialnitric oxide synthase T-786C single nucleotide polymorphisma putative genetic marker differentiating small versus largeruptured intracranial aneurysmsrdquo Stroke vol 34 no 11 pp2555ndash2559 2003

[51] V G Khurana I Meissner and F B Meyer ldquoUpdate on geneticevidence for rupture-prone compared with rupture-resistantintracranial saccular aneurysmsrdquo Neurosurgical Focus vol 17no 5 article E7 2004

[52] M Yoshimura M Nakayama Y Shimasaki et al ldquoA T-786rarrCmutation in the 51015840-flanking region of the endothelial nitric oxidesynthase gene and coronary arterial vasomotilityrdquo AmericanJournal of Cardiology vol 85 no 6 pp 710ndash714 2000

[53] M G Muhonen H Ooboshi M J Welsh B L Davidson andD D Heistad ldquoGene transfer to cerebral blood vessels aftersubarachnoid hemorrhagerdquo Stroke vol 28 no 4 pp 822ndash8291997

[54] K Toyoda F M Faraci A F Russo B L Davidson and DD Heistad ldquoGene transfer of calcitonin gene-related peptide tocerebral arteriesrdquo American Journal of Physiology vol 278 no2 pp H586ndashH594 2000

[55] S Ono T Komuro and R L Macdonald ldquoHeme oxygenase-1 gene therapy for prevention of vasospasm in ratsrdquo Journal ofNeurosurgery vol 96 no 6 pp 1094ndash1102 2002

[56] Y Watanabe Y Chu J J Andresen H Nakane F M Faraciand D D Heistad ldquoGene transfer of extracellular superoxidedismutase reduces cerebral vasospasm after subarachnoid hem-orrhagerdquo Stroke vol 34 no 2 pp 434ndash440 2003

[57] B L Sun F P Shen Q J Wu et al ldquoIntranasal delivery ofcalcitonin gene-related peptide reduces cerebral vasospasm inratsrdquo Frontiers in Bioscience vol 2 pp 1502ndash1513 2010

[58] T Ogawa D Hanggi Y Wu et al ldquoProtein therapy usingheme-oxygenase-1 fused to a polyarginine transduction domainattenuates cerebral vasospasm after experimental subarachnoidhemorrhagerdquo Journal of Cerebral Blood FlowampMetabolism vol31 no 11 pp 2231ndash2242 2011

[59] DNAtochinAWangVWT Liu et al ldquoThephosphorylationstate of eNOS modulates vascular reactivity and outcome ofcerebral ischemia in vivordquo Journal of Clinical Investigation vol117 no 7 pp 1961ndash1967 2007

[60] D M Dudzinski J Igarashi D Greif and T Michel ldquoThe reg-ulation and pharmacology of endothelial nitric oxide synthaserdquoAnnual Review of Pharmacology and Toxicology vol 46 pp235ndash276 2006

[61] M Sabri J Ai B Knight et al ldquoUncoupling of endothelial nitricoxide synthase after experimental subarachnoid hemorrhagerdquoJournal of Cerebral Blood Flow andMetabolism vol 31 no 1 pp190ndash199 2011

[62] A V R Santhanam L A Smith M Akiyama A G RosalesK R Bailey and Z S Katusic ldquoRole of endothelial NOsynthase phosphorylation in cerebrovascular protective effect ofrecombinant erythropoietin during subarachnoid hemorrhage-induced cerebral vasospasmrdquo Stroke vol 36 no 12 pp 2731ndash2737 2005

[63] M J McGirt J R Lynch A Parra et al ldquoSimvastatin increasesendothelial nitric oxide synthase and ameliorates cerebralvasospasm resulting from subarachnoid hemorrhagerdquo Strokevol 33 no 12 pp 2950ndash2956 2002

[64] T Sugawara R Ayer V Jadhav W Chen T Tsubokawa and JH Zhang ldquoSimvastatin attenuation of cerebral vasospasm aftersubarachnoid hemorrhage in rats via increased phosphoryla-tion of Akt and endothelial nitric oxide synthaserdquo Journal ofNeuroscience Research vol 86 no 16 pp 3635ndash3643 2008

[65] K Osuka Y Watanabe N Usuda K Atsuzawa J Yoshida andM Takayasu ldquoModification of endothelial nitric oxide synthasethrough AMPK after experimental subarachnoid hemorrhagerdquoJournal of Neurotrauma vol 26 no 7 pp 1157ndash1165 2009

[66] A K Vellimana E Milner T D Azad et al ldquoEndothelial nitricoxide synthase mediates endogenous protection against sub-arachnoid hemorrhage-induced cerebral vasospasmrdquo Strokevol 42 no 3 pp 776ndash782 2011

[67] U Forstermann ldquoJanus-faced role of endothelial NO synthasein vascular disease uncoupling of oxygen reduction from NOsynthesis and its pharmacological reversalrdquo Biological Chem-istry vol 387 no 12 pp 1521ndash1533 2006

[68] J R Lynch H Wang M J McGirt et al ldquoSimvastatin reducesvasospasm after aneurysmal subarachnoid hemorrhage resultsof a pilot randomized clinical trialrdquo Stroke vol 36 no 9 pp2024ndash2026 2005

[69] D C Hooper C J Steer C A Dinarello and A C PeacockldquoHaptoglobin and albumin synthesis in isolated rat hepatocytesResponse to potential mediators of the acute-phase reactionrdquoBiochimica et Biophysica Acta vol 653 no 1 pp 118ndash129 1981

[70] D J McCormick and M Z Atassi ldquoHemoglobin binding withhaptoglobin delineation of the haptoglobin binding site on the120572-chain of human hemoglobinrdquo Journal of Protein Chemistryvol 9 no 6 pp 735ndash742 1990

[71] M Kristiansen J H Graversen C Jacobsen et al ldquoIdentifica-tion of the haemoglobin scavenger receptorrdquo Nature vol 409no 6817 pp 198ndash201 2001

[72] J R McGill F Yang and W D Baldwin ldquoLocalization ofthe haptoglobin 120572 and 120573 genes (HPA and HPB) to humanchromosome 16q22 by in situ hybridizationrdquo Cytogenetics andCell Genetics vol 38 no 2 pp 155ndash157 1984

[73] J CWejmanDHovsepian J SWall J FHainfeld and JGreerldquoStructure and assembly of haptoglobin polymers by electronmicroscopyrdquo Journal of Molecular Biology vol 174 no 2 pp343ndash368 1984

[74] J C Wejman D Hovsepian and J S Wall ldquoStructure of hap-toglobin and the haptoglobin-hemoglobin complex by electronmicroscopyrdquo Journal of Molecular Biology vol 174 no 2 pp319ndash341 1984


[75] J JAVID ldquoThe effect of haptoglobin polymer size onhemoglobin binding capacityrdquo Vox Sanguinis vol 10 no3 pp 320ndash325 1965

[76] A Sasahara H Kasuya B Krischek et al ldquoGene expressionin a canine basilar artery vasospasm model a genome-widenetwork-based analysisrdquoNeurosurgical Review vol 31 no 3 pp283ndash290 2008

[77] B H Bowman and A Kurosky ldquoHaptoglobin the evolutionaryproduct of duplication unequal crossing over and point muta-tionrdquo Advances in Human Genetics vol 12 pp 189ndash453 1982

[78] G Pradilla T Garzon-Muvdi J J Ruzevick et al ldquoSystemicL-citrulline prevents cerebral vasospasm in haptoglobin 2-2transgenicmice after subarachnoid hemorrhagerdquoNeurosurgeryvol 70 no 3 pp 747ndash757 2012

[79] M T Froehler A Kooshkabadi R Miller-Lotan et alldquoVasospasm after subarachnoid hemorrhage in haptoglobin 2-2mice can be prevented with a glutathione peroxidase mimeticrdquoJournal of ClinicalNeuroscience vol 17 no 9 pp 1169ndash1172 2010

[80] P E Morange N Saut M C Alessi et al ldquoAssociation ofplasminogen activator inhibitor (PAI)-1 (SERPINE1) SNPs withmyocardial infarction plasmaPAI-1 andmetabolic parametersthe HIFMECH studyrdquo Arteriosclerosis Thrombosis and Vascu-lar Biology vol 27 no 10 pp 2250ndash2257 2007

[81] W Koch M Schrempf A Erl et al ldquo4G5G polymorphism andhaplotypes of SERPINE1 in atherosclerotic diseases of coronaryarteriesrdquoThrombosis and Haemostasis vol 103 no 6 pp 1170ndash1180 2010

[82] T Menges P W M Hermans S G Little et al ldquoPlasminogen-activator-inhibitor-1 4G5G promoter polymorphism and prog-nosis of severely injured patientsrdquo Lancet vol 357 no 9262 pp1096ndash1097 2001

[83] S Ye F R Green P Y Scarabin et al et al ldquoThe 4G5G geneticpolymorphism in the promoter of the plasminogen activatorinhibitor-1 (PAI-1) gene is associated with differences in plasmaPAI-1 activity but not with risk of myocardial infarction in theECTIM study Etude CasTemoins de Irsquonfarctus du MycocarderdquoThrombosis and Haemostasis vol 74 no 3 pp 837ndash841 1995

[84] W J Strittmatter and C Bova Hill ldquoMolecular biology ofapolipoproteinrdquoCurrent Opinion in Lipidology vol 13 no 2 pp119ndash123 2002

[85] M I Kamboh ldquoApolipoprotein E polymorphism and suscepti-bility to Alzheimerrsquos diseaserdquo Human Biology vol 67 no 2 pp195ndash215 1995

[86] R Rao V Tah J P Casas et al ldquoIschaemic stroke subtypes andtheir genetic basis a comprehensive meta-analysis of small andlarge vessel strokerdquo European Neurology vol 61 no 2 pp 76ndash86 2009

[87] X Sun and Y Jiang ldquoGenetic susceptibility to traumatic braininjury and apolipoprotein E generdquo Chinese Journal of Trauma-tology vol 11 no 4 pp 247ndash252 2008

[88] Z D Guo X C Sun and J H Zhang ldquoThe role of apolipopro-tein e in the pathological events following subarachnoid hem-orrhage a reviewrdquoActa Neurochirurgica vol 110 part 2 pp 5ndash72011

[89] C L Lendon J M Harris A L Pritchard J A R Nicoll GM Teasdale and G Murray ldquoGenetic variation of the APOEpromoter and outcome after head injuryrdquoNeurology vol 61 no5 pp 683ndash685 2003

[90] Y Jiang X Sun L Gui et al ldquoCorrelation between APOE-491AApromoter in 1205764 carriers and clinical deterioration in earlystage of traumatic brain injuryrdquo Journal of Neurotrauma vol 24no 12 pp 1802ndash1810 2007

[91] K Yamashiro A B Milsom J Duchene et al ldquoAlterations innitric oxide and endothelin-1 bioactivity underlie cerebrovas-cular dysfunction in ApoE-deficient micerdquo Journal of CerebralBlood Flow and Metabolism vol 30 no 8 pp 1494ndash1503 2010

[92] M Chow A S Dumont N F Kassell et al ldquoEndothelinreceptor antagonists and cerebral vasospasm an updaterdquo Neu-rosurgery vol 51 no 6 pp 1333ndash1342 2002

[93] A Hashimoto G Miyakoda Y Hirose and T Mori ldquoActi-vation of endothelial nitric oxide synthase by cilostazolvia a cAMPprotein kinase A- and phosphatidylinositol 3-kinaseAkt-dependentmechanismrdquoAtherosclerosis vol 189 no2 pp 350ndash357 2006

[94] M W Ledbetter J K Preiner C F Louis and J R Mickel-son ldquoTissue distribution of ryanodine receptor isoforms andalleles determined by reverse transcription polymerase chainreactionrdquo Journal of Biological Chemistry vol 269 no 50 pp31544ndash31551 1994

[95] V Sorrentino ldquoThe Ryanodine Receptor Family of IntracellularCalcium Release Channelsrdquo Advances in Pharmacology vol 33pp 67ndash90 1995

[96] M Koide M A Nystoriak G Krishnamoorthy et al ldquoReducedCa2+ spark activity after subarachnoid hemorrhage disables BKchannel control of cerebral artery tonerdquo Journal of CerebralBlood Flow and Metabolism vol 31 no 1 pp 3ndash16 2011

[97] M T Nelson H Cheng M Rubart et al ldquoRelaxation of arterialsmooth muscle by calcium sparksrdquo Science vol 270 no 5236pp 633ndash637 1995

[98] G C Wellman and M T Nelson ldquoSignaling between SR andplasmalemma in smooth muscle sparks and the activation ofCa2+-sensitive ion channelsrdquoCell Calcium vol 34 no 3 pp 211ndash229 2003

[99] G C Wellman D J Nathan C M Saundry et al ldquoCa2+ sparksand their function in human cerebral arteriesrdquo Stroke vol 33no 3 pp 802ndash808 2002

[100] H J Knot N B Standen and M T Nelson ldquoRyanodinereceptors regulate arterial diameter and wall [Ca2+] in cerebralarteries of rat via Ca2+-dependent K+ channelsrdquo Journal ofPhysiology vol 508 part 1 pp 211ndash221 1998

[101] K Abe andH Kimura ldquoThe possible role of hydrogen sulfide asan endogenous neuromodulatorrdquo Journal of Neuroscience vol16 no 3 pp 1066ndash1071 1996

[102] C W Leffler H Parfenova J H Jaggar and R Wang ldquoCarbonmonoxide and hydrogen sulfide gaseous messengers in cere-brovascular circulationrdquo Journal of Applied Physiology vol 100no 3 pp 1065ndash1076 2006

[103] G Yang L Wu B Jiang et al ldquoH2S as a physiologic vasore-laxant hypertension in mice with deletion of cystathionine 120574-lyaserdquo Science vol 322 no 5901 pp 587ndash590 2008

[104] A Zubkov L Miao and J Zhang ldquoSignal transduction of ET-1 in contraction of cerebral arteriesrdquo Journal of CardiovascularPharmacology vol 44 supplement 1 pp S24ndashS26 2004

[105] J F Clark M Reilly and F R Sharp ldquoOxidation of bilirubinproduces compounds that cause prolonged vasospasm of ratcerebral vessels a contributor to subarachnoid hemorrhage-induced vasospasmrdquo Journal of Cerebral Blood Flow andMetabolism vol 22 no 4 pp 472ndash478 2002

[106] H Suzuki Y Hasegawa K Kanamaru and J H ZhangldquoMitogen-activated protein kinases in cerebral vasospasm aftersubarachnoid hemorrhage a reviewrdquoActa Neurochirurgica vol110 part 1 pp 133ndash139 2011

[107] X D Zhao Y T Zhou Y Wu et al ldquoPotential role ofRas in cerebral vasospasm after experimental subarachnoid


hemorrhage in rabbitsrdquo Journal of Clinical Neuroscience vol 17no 11 pp 1407ndash1411 2010

[108] H M Lander J S Ogiste K K Teng and A Novogrodskyldquop21(ras) as a common signaling target of reactive free radicalsand cellular redox stressrdquo Journal of Biological Chemistry vol270 no 36 pp 21195ndash21198 1995

[109] M Yamaguchi C Zhou A Nanda and J H Zhang ldquoRasprotein contributes to cerebral vasospasm in a canine double-hemorrhage modelrdquo Stroke vol 35 no 7 pp 1750ndash1755 2004

[110] G Kusaka H Kimura I Kusaka E Perkins A Nanda andJ H Zhang ldquoContribution of Src tyrosine kinase to cerebralvasospasm after subarachnoid hemorrhagerdquo Journal of Neuro-surgery vol 99 no 2 pp 383ndash390 2003

[111] J H Laher IZhang ldquoProtein kinase C and cerebral vasospasmrdquoJournal of Cerebral Blood Flow amp Metabolism vol 21 no 8 pp887ndash906 2001

[112] T Sasaki H Kasuya H Onda et al ldquoRole of p38 mitogen-activated protein kinase on cerebral vasospasm after subarach-noid hemorrhagerdquo Stroke vol 35 no 6 pp 1466ndash1470 2004

[113] Q Jiang RHuang S Cai andC L AWang ldquoCaldesmon regu-lates themotility of vascular smoothmuscle cells bymodulatingthe actin cytoskeleton stabilityrdquo Journal of Biomedical Sciencevol 17 no 1 article 6 2010

[114] J S Rawlings KM Rosler andD AHarrison ldquoThe JAKSTATsignaling pathwayrdquo Journal of Cell Science vol 117 no 8 pp1281ndash1283 2004

[115] K Osuka Y Watanabe K Yamauchi et al ldquoActivation of theJAK-STAT signaling pathway in the rat basilar artery aftersubarachnoid hemorrhagerdquo Brain Research vol 1072 no 1 pp1ndash7 2006

[116] G Chen J Wu C Sun et al ldquoPotential role of JAK2 in cere-bral vasospasm after experimental subarachnoid hemorrhagerdquoBrain Research vol 1214 pp 136ndash144 2008

[117] KOsuka YWatanabe NUsuda K Atsuzawa TWakabayashiand M Takayasu ldquoOxidative stress activates STAT1 in basilararteries after subarachnoid hemorrhagerdquo Brain Research vol1332 pp 12ndash19 2010

[118] J M Findlay B K A Weir K Kanamaru et al ldquoIntrathecalfibrinolytic therapy after subarachnoid hemorrhage dosagestudy in a primatemodel and review of the literaturerdquoCanadianJournal of Neurological Sciences vol 16 no 1 pp 28ndash40 1989

[119] B R Clower Y Yamamoto L Cain D E Haines and RR Smith ldquoEndothelial injury following experimental sub-arachnoid hemorrhage in rats effects on brain blood flowrdquoAnatomical Record vol 240 no 1 pp 104ndash114 1994

[120] C O Borel A McKee A Parra et al ldquoPossible role for vascularcell proliferation in cerebral vasospasm after subarachnoidhemorrhagerdquo Stroke vol 34 no 2 pp 427ndash432 2003

[121] R M Pluta E H Oldfield and R J Boock ldquoReversal andprevention of cerebral vasospasm by intracarotid infusionsof nitric oxide donors in a primate model of subarachnoidhemorrhagerdquo Journal of Neurosurgery vol 87 no 5 pp 746ndash751 1997

[122] M Feletou Y Huang and P M Vanhoutte ldquoEndothelium-mediated control of vascular tone COX-1 and COX-2 prod-uctsrdquo British Journal of Pharmacology vol 164 no 3 pp 894ndash912 2011

[123] K Satoh Y Fukumoto and H Shimokawa ldquoRho-kinaseimportant new therapeutic target in cardiovascular diseasesrdquoAmerican Journal of Physiology vol 301 no 2 pp H287ndashH2962011

[124] M Sato E Tani H Fujikawa and K Kaibuchi ldquoInvolvement ofRho-kinase-mediated phosphorylation of myosin light chain in

enhancement of cerebral vasospasmrdquo Circulation Research vol87 no 3 pp 195ndash200 2000

[125] M Amano M Ito K Kimura et al ldquoPhosphorylation andactivation of myosin by Rho-associated kinase (Rho-kinase)rdquoJournal of Biological Chemistry vol 271 no 34 pp 20246ndash20249 1996

[126] G J Pyne-Geithman S G Nair D N Caudell and J F ClarkldquoPKC and Rho in vascular smoothmuscle activation by BOXesand SAH CSFrdquo Frontiers in Bioscience vol 13 no 4 pp 1526ndash1534 2008

[127] G Wickman C Lan and B Vollrath ldquoFunctional roles of theRhoRho kinase pathway and protein kinase C in the regulationof cerebrovascular constriction mediated by hemoglobin rele-vance to subarachnoid hemorrhage and vasospasmrdquoCirculationResearch vol 92 no 7 pp 809ndash816 2003

[128] H Shimokawa and A Takeshita ldquoRho-kinase is an importanttherapeutic target in cardiovascular medicinerdquo ArteriosclerosisThrombosis and Vascular Biology vol 25 no 9 pp 1767ndash17752005

[129] YWatanabe F M Faraci and D D Heistad ldquoActivation of rho-associated kinase during augmented contraction of the basilarartery to serotonin after subarachnoid hemorrhagerdquo AmericanJournal of Physiology vol 288 no 6 pp H2653ndashH2658 2005

[130] K Obara S Nishizawa M Koide et al ldquoInteractive roleof protein kinase C-120575 with Rho-kinase in the developmentof cerebral vasospasm in a canine two-hemorrhage modelrdquoJournal of Vascular Research vol 42 no 1 pp 67ndash76 2005

[131] C Lan D Das A Wloskowicz and B Vollrath ldquoEndothelin-1modulates hemoglobin-mediated signaling in cerebrovascularsmooth muscle via RhoARho kinase and protein kinase CrdquoAmerican Journal of Physiology vol 286 no 1 pp H165ndashH1732004

[132] P Nigro K Satoh M R OrsquoDell et al ldquoCyclophilin A isan inflammatory mediator that promotes atherosclerosis inapolipoprotein E-deficient micerdquo The Journal of ExperimentalMedicine vol 208 no 1 pp 53ndash66 2011

[133] K Satoh T Matoba J Suzuki et al ldquoCyclophilin a mediatesvascular remodeling by promoting inflammation and vascularsmooth muscle cell proliferationrdquo Circulation vol 117 no 24pp 3088ndash3098 2008

[134] K Satoh P Nigro and B C Berk ldquoOxidative stress andvascular smooth muscle cell growth a mechanistic linkage bycyclophilin Ardquo Antioxidants and Redox Signaling vol 12 no 5pp 675ndash682 2010

[135] S Iwabuchi T Yokouchi M Hayashi et al ldquoIntra-arterialadministration of fasudil hydrochloride for vasospasm follow-ing subarachnoid haemorrhage experience of 90 casesrdquo ActaNeurochirurgica vol 110 part 2 pp 179ndash181 2011

[136] H Ooboshi ldquoGene therapy as a novel pharmaceutical interven-tion for strokerdquoCurrent Pharmaceutical Design vol 17 no 5 pp424ndash433 2011

[137] T Van-Assche V Huygelen M J Crabtree and C AntoniadesldquoGene therapy targeting inflammation in atherosclerosisrdquo Cur-rent Pharmaceutical Design vol 17 no 37 pp 4210ndash4223 2011

[138] S Ono T Komuro and R L Macdonald ldquoAdenovirus-mediated heme oxygenase-1 gene transfection preventshemoglobin-induced contraction of rat basilar arteryrdquo ActaNeurochirurgica vol 77 pp 93ndash96 2001

[139] B E Jaski M L Jessup D M Mancini et al ldquoCalciumupregulation by percutaneous administration of gene therapyin cardiac disease (CUPID trial) a first-in-human phase 12clinical trialrdquo Journal of Cardiac Failure vol 15 no 3 pp 171ndash181 2009


[140] M Jessup B Greenberg D Mancini et al ldquoCalcium upreg-ulation by percutaneous administration of gene therapy incardiac disease (CUPID) a phase 2 trial of intracoronary genetherapy of sarcoplasmic reticulumCa2+-ATPase in patients withadvanced heart failurerdquo Circulation vol 124 no 3 pp 304ndash3132011

[141] Y Kawase D Ladage and R J Hajjar ldquoRescuing the failingheart by targeted gene transferrdquo Journal of the American Collegeof Cardiology vol 57 no 10 pp 1169ndash1180 2011

[142] F Sedighiani and S Nikol ldquotherapy in vascular diseaserdquoSurgeon vol 9 no 6 pp 326ndash335 2011

[143] S R Schwarze A Ho A Vocero-Akbani and S F DowdyldquoIn vivo protein transduction delivery of a biologically activeprotein into the mouserdquo Science vol 285 no 5433 pp 1569ndash1572 1999

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014


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Behavioural Neurology

EndocrinologyInternational Journal of



Disease Markers


BioMed Research International

OncologyJournal of



Oxidative Medicine and Cellular Longevity


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The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom


oxide (NO) concentration increase prostaglandin synthesisand increase lipid peroxidation [9 11ndash13] Such changes inthe vascular equilibrium can lead to the activation of pro-vasospasm signaling pathways and the synthesis of inflam-matory gene products This process occurs in parallel to thedelayed cerebral ischemia (DCI) resulting frommicrothrom-boses and cortical spreading ischemia [14 15]

2 Genetics in CV

Whilemuchwork has been done to characterize the signalingpathways implicated in CV the field still lacks a definitiveexplanatory model with robust predictability and therapeutictargets Several presumptive targets have been proposed withonly modest gains For example clazosentan an endothelinreceptor antagonist has shown great attenuation of angio-graphic vasospasm in preclinical and clinical studies butno improvement in neurological outcomes [16] In contrastnimodipine a calcium channel blocker improves func-tional outcomes without a parallel reduction in angiographicvasospasm [17] However the field of genetics offers a newinsight

An active area of research is the exploration of thegenetic basis for CV which has previously been supported bypopulation studies [18] New advances in molecular geneticshave revealed several genes whose products are presumptivemediators of CV and genetic polymorphisms that portendincreased CV risk andor poorer outcomes Understandingthe genetic mechanism of disease generation may provideinsight into novel therapeutic avenues In this review we willsummarize the most recent research in the following areasregarding genetics and CV (1) prognostic role of genetics (2)key signaling mediators involved and (3) gene therapy andgene delivery

21 Prognostic Factors Stratifying risk based on next gen-eration sequencing is gradually becoming integrated intomedical practice [31] In cardiovascularmedicine indicationson the use of drugs such as clopidogrel warfarin and statinshave already been made based on the patientrsquos genotype[32ndash34] Genetic screening of family members of patientsdiagnosed with familial hypercholesterolemia is currentlyrecommended in the UK [35]

Genetic risk stratification for CV holds great potentialClose family members of patients with aneurysms may bescreened for their own susceptibility for aneurysm formationand rupture Genomic biomarkersmay also be used to stratifySAH patients for more intensive monitoring according tovasospasm risk as well as informing medication administra-tion

Genomewide and other gene association studies haveidentified several genes that may play a larger role in develop-ing quick and inexpensive screening protocols in SAH Thisrepresents an update on a genetics review by Ducruet andcolleagues [36] with attention to recent discoveries reportedin the literatureThe following is a summary of genetic mark-ers associated with SAH and CV with evidence for diseasemechanisms as well as implicated polymorphisms (Table 1)

211 Catechol-O-methyltransferase (COMT) Cate-chol-a-mi-nes have been implicated in the development of acuteCV following SAH [37 38] COMT a key enzyme in thedegradation of catecholamines has been shown to play a rolein acute CV A rat model has shown increased expression ofCOMT and catecholamines following SAH induction [39] Astudy of 167 Chinese Han SAH patients showed that patientswith the COMT-A allele AA genotype were more likelyto develop acute CV [40] This polymorphism may be abiomarker for predicting poor outcomes in patients withaneurysms that may later rupture

212 Endothelial Nitric Oxide Synthase (eNOS) GeneEndothelial nitric oxide synthase (eNOS) gene which isfound on chromosome 7q35 plays an important role in CVand other cardiovascular diseases [41] eNOS is present inthe endothelium of the major cerebral arteries and producesnitric oxide (NO) a potent vasodilator Constitutive levelsof NO inhibit platelet aggregation vascular smooth muscleproliferation and inflammation [9 23 42ndash44] Perivascularoxyhemoglobin released after SAH scavenges NO generatedby eNOS decreasing NO-mediated vasorelaxation andcontributing to the onset of vasospasm [45ndash47]

Clinically decreased levels of NO in the CSF have beenreported in aSAH patients Overexpression of the eNOSgene has been shown to be vasoprotective in humans andcanines in the setting of SAH [48 49] Polymorphisms of theeNOS genes are linked to intracranial aneurysm formation[50 51] and coronary vasospasm [52] Genetic associationstudies have shown that eNOS 7-786 gene SNPs predisposeaSAH patients for vasospasm [19ndash23] However the variousfindings are contradictory showing either an effect withthe T allele C allele or no clear association This apparentdiscrepancy is likely attributable to the heterogeneity ofvasospasm definition as well as the complex regulation of theeNOS gene

The activity of eNOS is tightly regulated at manystages including transcription substrate availability cofac-tors protein-protein interactions posttranslationalmodifica-tions and dimerization [59 60] The literature is mixed onwhether eNOS activity is increased [61] decreased [62] orunchanged [63ndash66] following SAH Further it is still unclearwhat role SAH plays in the phosphorylation of eNOS [66]

eNOS is physiologically a homodimer but under patho-logical conditions decouples and forms a ferrous-dioxygencomplex which has a tendency to form superoxide radicalsinstead of NO [67] Recent studies by Sabri and colleagueshave shown that SAH leads to increased phosphorylationof eNOS on Ser1177 and subsequent uncoupling whichdecreases NO availability while simultaneously increasingthe production of superoxide Superoxide may further reactwith remaining NO to form peroxynitrite which continuesto deplete residual NO [61] While it is known that simvas-tatin can mitigate vasospasm [63 68] recent work suggeststhat simvastatin may work by recoupling eNOS to increaseNO production and decrease the production of superoxide[61] This may further explain its mechanism of attenuatingvasospasm clinically and in other animal models [63 64]


















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Documents

Review Article Genetics of Cerebral Vasospasmdownloads.hindawi.com/journals/nri/2013/291895.pdf · muscle contraction of cerebral arteries in mammals [ ]. A ... key signaling mediators