Effects of alterations of GAD by lentivirus mediated gene transfer on seizure severity in genetically epilepsy prone rats

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ABSTRACTS / Experimental Neurology 198 (2006) 558 – 597

Effects of alterations of GAD by lentivirus mediated gene transfer on seizure severity in genetically epilepsy prone rats S.A. Epps 1, D.E. Venable 1, C.L. Faingold 2, S.P. Wilson 3, J.R. Coleman 1,3 1 Department of Psychology, University of South Carolina, Columbia, USA 2 Department of Pharmacology, School of Medicine, Southern Illinois University, Springfield, USA 3 Department of Pharmacology, Physiology, and Neuroscience, School of Medicine, University of South Carolina, Columbia, USA Our previous studies have shown the effectiveness of using lentiviral gene transfer to alter GAD production to reduce seizure behaviors in a developmental model of epilepsy (audiogenic seizures, AGS). Of current interest are the effects of these viral vectors on the genetic model of AGS, using Genetically Epilepsy Prone Rats (GEPRs) selectively bred in-house at Southern Illinois University School of Medicine. Adult GEPRs were induced to seizure activity (120 dB white noise stimulation for a maximum of 1 min). Two AGS-tests were performed before surgery and five tests during the 30-day period following surgery. The central nucleus of the inferior colliculus was bilaterally injected with lentivirus vectors (multiply attenuated, replication defective, and self-inactivating) encoding GAD65 sense. While there was no significant change in latency to wild run, the average latency of all five post-tests was marginally increased, t(7) = 2.251, P = 0.059. Paired t test analysis also showed an increase in duration of seizure behaviors during posttest 2, t(7) = 3.06, P < 0.05. Additional work using viral constructs, perhaps involving larger areas of infection of epileptogenic tissues, will provide further evidence that altering GABA mechanisms can effectively reduce seizure activity in a genetic model of epilepsy. (Supported by NSF SES-0244632 and EPSCoR EPS-0132573/NIH BRIN 8-P0RR16461A (JRC), Barry M. Goldwater Fellowship (SAE), and Epilepsy Foundation Fellowship (DEV)). doi:10.1016/j.expneurol.2006.02.040

DJ-1 protects dopamine neurons by selective activation of either glutathione or heat shock protein C.R. Freed, W. Zhou Div. of Clinical Pharmacology, Dept. of Medicine, and the Neuroscience Program, Univ. of Colorado Health Sciences Center, Denver, CO, USA Mutations in DJ-1 which interfere with protein dimerization lead to early onset Parkinson’s disease with autosomal recessive inheritance. To understand the normal function of DJ-1, we have overexpressed the gene in cultured dopaminergic cells which were then subjected to chemical stress. In the rat dopaminergic cell line, N27, and in primary dopamine neurons, overexpression of wild type (WT) DJ-1 protected cells from death induced by hydrogen peroxide, 6-hydroxydopamine, and dopamine, but not the proteasome inhibitor lactacystin. Overexpressing the L166P

mutant DJ-1 had no protective effect. By contrast, knocking down endogenous DJ-1 with antisense DJ-1 rendered cells more susceptible to oxidative damage. We have found that DJ-1 improves survival by increasing cellular glutathione (GSH) levels through an increase in the rate-limiting enzyme, glutamate cysteine ligase, with no change in glutathione synthetase. Blocking GSH synthesis eliminated the beneficial effect of DJ1. Protection could be restored by adding exogenous GSH. WT DJ-1 reduced cellular reactive oxygen species and reduced the levels of protein oxidation caused by oxidative stress. By a separate mechanism, overexpressing WT DJ-1 inhibited the protein aggregation and cytotoxicity usually caused by A53T human a-synuclein. Under these circumstances, DJ-1 increased the level of heat shock protein 70 (Hsp70) but did not change the GSH level. Our data indicate that DJ-1 protects dopaminergic neurons from oxidative stress through upregulation of glutathione synthesis and from the toxic consequences of mutant human asynuclein through increased expression of Hsp70. Drugs which increase the expression of DJ-1 may prevent the progression of Parkinson’s disease. (Supported by the American Parkinson Disease Association and the Mitchell Family Foundation). doi:10.1016/j.expneurol.2006.02.041

The modern era of surgical trial designs: Perspectives of Parkinson’s disease (PD) researchers T.B. Freeman 1,2, D.E. Vawter 3, K.G. Gervais, A.W. Prehn, R.G. De Vries, J.E. Garrett, T.Q. McIndoo 1 Neurosurgery, University of South Florida, Tampa, USA 2 Center of Excellence for Aging and Brain Repair, University of South Florida, Tampa, USA 3 Minnesota Center for Health Care Ethics, College of St. Catherine Minneapolis, Minneapolis, MN, USA It is unethical for surgeons and patients to be required to make surgical decisions with insufficient scientific information. We interviewed 48 North American surgical researchers studying PD about modern surgical trial designs. Most of the participants were either neurologists (41%) or neurosurgeons (28%). A separate research funding task force included representatives from academic centers, device manufacturers, Federal and State agencies, patient advocacy groups, and thirdparty payers. Participants concluded that: (1) surgical placebocontrolled trials for deep brain stimulation were ethically and practically infeasible, but placebo-controlled surgical trials of cellular implants were ethically justified and even mandatory; (2) the U.S. has inadequate infrastructure to support quality surgical trials, including problems with FDA requirements, surgeon training in research design, IRB deficiencies, lack of consensus on surgical research trial ethics, common practices of offering research interventions as proven therapies, and lack of funding for surgical trials which are exceptionally costly; (3) device manufacturers have fewer incentives to fund trials than their pharmaceutical counterparts; (4) PD patients (without dementia) are well-informed and capable of providing valid informed consent; and (5) novel funding mechanisms are