RESUMO
Vascular endothelial growth factor (VEGF) plays a role in angiogenesis and has been shown to be neuroprotective following central nervous system trauma. In the present study we evaluated the pro-angiogenic and neuroprotective effects of an engineered zinc-finger protein transcription factor transactivator targeting the vascular endothelial growth factor A (VEGF-ZFP). We used two virus delivery systems, adeno-virus and adeno-associated virus, to examine the effects of early and delayed VEGF-A upregulation after brain trauma, respectively. Male Sprague-Dawley rats were subject to a unilateral fluid percussion injury (FPI) of moderate severity (2.2-2.5 atm) followed by intracerebral microinjection of either adenovirus vector (Adv) or an adeno-associated vector (AAV) carrying the VEGF-ZFP construct. Adv-VEGF-ZFP-treated animals had significantly fewer TUNEL positive cells in the injured penumbra of the cortex (p<0.001) and hippocampus (p=0.001) relative to untreated rats at 72 h post-injury. Adv-VEGF-ZFP treatment significantly improved fEPSP values (p=0.007) in the CA1 region relative to injury alone. Treatment with AAV2-VEGF-ZFP resulted in improved post-injury microvascular diameter and improved functional recovery on the balance beam and rotarod task at 30 days post-injury. Collectively, the results provide supportive evidence for the concept of acute and delayed treatment following TBI using VEGF-ZFP to induce angiogenesis, reduce cell death, and enhance functional recovery.
Assuntos
Lesões Encefálicas/terapia , Terapia Genética , Fator A de Crescimento do Endotélio Vascular/genética , Dedos de Zinco/genética , Animais , Western Blotting , Lesões Encefálicas/patologia , Lesões Encefálicas/psicologia , Região CA1 Hipocampal/patologia , Capilares/patologia , Dependovirus/genética , Potenciais Pós-Sinápticos Excitadores/fisiologia , Vetores Genéticos , Marcação In Situ das Extremidades Cortadas , Potenciação de Longa Duração , Masculino , Microinjeções , Neovascularização Fisiológica/fisiologia , Ratos , Ratos Sprague-Dawley , Recuperação de Função Fisiológica , Fator A de Crescimento do Endotélio Vascular/fisiologiaRESUMO
We have engineered a human adenovirus, ONYX-411, that selectively replicates in human tumor cells, but not normal cells, depending upon the status of their retinoblastoma tumor suppressor protein (pRB) pathway. Early and late viral gene expression as well as DNA replication were significantly reduced in a functional pRB-pathway-dependent manner, resulting in a restricted replication profile similar to that of nonreplicating adenoviruses in normal cells both in vitro and in vivo. In contrast, the viral life cycle and tumor cell killing activity of ONYX-411 was comparable to that of wild-type adenovirus following infection of human tumor cells in vitro as well as after systemic administration in tumor-bearing animals.
