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author:("basmi, Mehdi")
1.  Postischemic IGF-1 gene transfer promotes neurovascular regeneration after experimental stroke 
Promoting neural regeneration after cerebral infarction has emerged as a potential approach for the treatment of stroke. Insulin-like growth factor 1 (IGF-1) possesses both neurotrophic and angiogenic properties. The aim of this study is to determine whether postischemic gene transfer of IGF-1 enhances neurovascular regeneration in a mouse model of permanent focal cerebral ischemia. Long-term cerebral IGF-1 overexpression was achieved with adeno-associated viral vector (AAV) via stereotaxic injection at 24 h after stroke. AAV-GFP or saline was injected as control. The success of postischemic gene transduction was confirmed by a strong green fluorescent protein signal and by increased IGF-1 protein expression in the peri-infarct region. Postischemic gene transfer of IGF-1 significantly enhanced vascular density at 8 weeks post stroke in the peri-infarct and injection needle tract area compared to AAV-GFP or saline treatment, as shown by immunohistochemical staining with vascular marker lectin. Furthermore, increased vascular density was associated with improved local vascular perfusion. Immunohistochemical staining with neuronal progenitor marker DCX and cell proliferation marker BrdU indicated that AAV-IGF-1 treatment potently increased neurogenesis compared to AAV-GFP injection. These data demonstrate that postischemic treatment of IGF-1 effectively promoted neural and vascular regeneration in the chronic stage of cerebral infarction.
doi:10.1038/jcbfm.2009.75
PMCID: PMC2763573  PMID: 19513085
angiogenesis; IGF-1; neurovascular; regeneration; stroke
2.  Long-Term Reversal of Cholinergic Neuronal Decline in Aged Non-Human Primates by Lentiviral NGF Gene Delivery 
Experimental neurology  2008;215(1):153-159.
Spontaneous atrophy of basal forebrain cholinergic neurons occurs with aging in the non-human primate brain. Short-term reversal of this atrophy has been reported following ex vivo Nerve Growth Factor (NGF) gene delivery, but long-term effects of in vivo NGF gene delivery in the aged primate brain have not to date been examined. We tested the hypothesis that long-term lentiviral NGF intraparenchymal gene delivery would reverse age-related cholinergic decline, without induction of adverse effects previously observed following sustained intracerebroventricular growth factor protein exposure. Three aged rhesus monkeys underwent intraparenchymal lentiviral NGF gene delivery to the cholinergic basal forebrain. One year later, cholinergic neuronal numbers were quantified stereologically and compared to findings in four control, non-treated aged monkeys and four young adult monkeys. Safety was assessed on several variables related to growth factor exposure. We now report that lentiviral gene delivery of NGF to the aged primate basal forebrain sustains gene expression for at least one year, and significantly restores cholinergic neuronal markers to levels of young monkeys. Aging resulted in a significant 17% reduction (p<0.05) in the number of neurons labeled for the cholinergic marker p75 among basal forebrain neurons. Lentiviral NGF gene delivery induced significant (p<0.05) and nearly complete recovery of p75-labeled neuronal numbers in aged subjects to levels observed in young monkeys. Similarly, the size of cholinergic neurons in aged monkeys was significantly reduced by 16% compared to young subjects (p<0.05), and lentiviral NGF delivery to aged subjects induced complete recovery of neuronal size. Intraparenchmyal NGF gene delivery over a one-year period did not result in systemic leakage of NGF, activation of inflammatory markers in the brain, pain, weight loss, Schwann cell migration, or formation of anti-NGF antibodies. These findings indicate that extended trophic support to neurons in the non-human primate brain reverses age-related neuronal atrophy. These findings also support the safety and feasibility of lentiviral NGF gene transfer for potential testing in human clinical trials to protect degenerating cholinergic neurons in Alzheimer’s disease.
doi:10.1016/j.expneurol.2008.10.004
PMCID: PMC2632603  PMID: 19013154
Alzheimer’s disease; cholinergic; chronic; gene therapy; neurotrophic factor; neurotrophin; p75; rhesus
3.  Antioxidant or neurotrophic factor treatment preserves function in a mouse model of neovascularization-associated oxidative stress 
In several disease states, abnormal growth of blood vessels is associated with local neuronal degeneration. This is particularly true in ocular diseases such as retinal angiomatous proliferation (RAP) and macular telangiectasia (MacTel), in which, despite the absence of large-scale leakage or hemorrhage, abnormal neovascularization (NV) is associated with local neuronal dysfunction. We describe here a retinal phenotype in mice with dysfunctional receptors for VLDL (Vldlr–/– mice) that closely resembles human retinal diseases in which abnormal intra- and subretinal NV is associated with photoreceptor cell death. Such cell death was evidenced by decreased cone and, to a lesser extent, rod opsin expression and abnormal electroretinograms. Cell death in the region of intraretinal vascular abnormalities was associated with an increased presence of markers associated with oxidative stress. Oral antioxidant supplementation protected against photoreceptor degeneration and preserved retinal function, despite the continued presence of abnormal intra- and subretinal vessels. What we believe to be novel, Müller cell–based, virally mediated delivery of neurotrophic compounds specifically to sites of NV was also neuroprotective. These observations demonstrate that neuronal loss secondary to NV can be prevented by the use of simple antioxidant dietary measures or cell-based delivery of neurotrophic factors, even when the underlying vascular phenotype is not altered.
doi:10.1172/JCI35977
PMCID: PMC2648679  PMID: 19188685
4.  Intraparenchymal spinal cord delivery of adeno-associated virus IGF-1 is protective in the SOD1G93A model of ALS 
Brain research  2007;1185:256-265.
The potent neuroprotective activities of neurotrophic factors, including insulin-like growth factor 1 (IGF-1), make them promising candidates for treatment of amyotrophic lateral sclerosis (ALS). In an effort to maximize rate of motor neuron transduction, achieve high levels of spinal IGF-1, and thus enhance therapeutic benefit, we injected an adeno-associated virus 2 (AAV2)-based vector encoding human IGF-1 (CERE-130) into lumbar spinal cord parenchyma of SOD1G93A mice. We observed robust and long-term intraspinal IGF-1 expression and partial rescue of lumbar spinal cord motor neurons, as well as sex-specific delayed disease onset, weight loss, decline in hindlimb grip strength and increased animal survival.
doi:10.1016/j.brainres.2007.09.034
PMCID: PMC2265207  PMID: 17963733
Adeno; associated virus; insulin; like growth factor 1; gene therapy; neurodegeneration; amyotrophic lateral sclerosis; neuroprotection
5.  Insulin Growth Factor-1 Gene Transfer Enhances Neurovascular Remodeling and Improves Long-Term Stroke Outcome in Mice 
Background and Purpose
Insulin-like growth factor I (IGF-1) is a pleiotropic growth factor that has been demonstrated to protect against acute ischemic brain injury. Whether IGF-1 improves long-term functional outcome after ischemic stroke is not known. The aim of this study is to examine whether IGF-1 overexpression through adeno-associated virus (AAV) -mediated gene transfer enhances neurovascular remodeling and improves functional outcome in a mouse model of focal cerebral ischemia.
Methods
Long-term cerebral IGF-1 overexpression was achieved with the AAV transduction system through stereotaxic injection. Control mice were injected with AAV–green fluorescent protein or saline. Three weeks after gene transfer, the mice underwent permanent distal middle cerebral artery occlusion. Histological and behavioral analyses were performed at day 21 after middle cerebral artery occlusion.
Results
IGF-1 gene transfer compared with control treatment significantly improved motor performance assessed by sensorimotor tests. The functional recovery was accompanied by reduced volume of cerebral infarction. Immunohistochemical analysis with endothelial cell marker CD31 revealed that IGF-1 gene transfer potently increased neovessel formation in the periinfarct and injection needle tract area compared with AAV–green fluorescent protein transduction. Increased vascular density was associated with increased local vascular perfusion. Additionally, AAV-IGF-1 treatment enhanced neurogenesis in the subventricular zone compared with AAV–green fluorescent protein treatment.
Conclusions
These data demonstrate that IGF-1 overexpression promoted long-lasting functional recovery after cerebral infarction. The improved functional performance was paralleled by enhanced neovascularization and neurogenesis.
doi:10.1161/STROKEAHA.107.500801
PMCID: PMC2553752  PMID: 18309153
angiogenesis; gene transfer; IGF-1; neurogenesis; stroke
6.  Minimum Requirements for Efficient Transduction of Dividing and Nondividing Cells by Feline Immunodeficiency Virus Vectors 
Journal of Virology  1999;73(6):4991-5000.
The development of gene delivery vectors based on feline immunodeficiency virus (FIV) is an attractive alternative to vectors based on primate sources for the delivery of genes into humans. To investigate the requirements for efficient transduction of dividing and nondividing cells by vector particles based on FIV, a series of packaging and vector constructs was generated for which viral gene expression was minimized and from which unnecessary cis-acting sequences were deleted. Pseudotyped vector particles produced in 293T cells were used to transduce various target cells, including contact-inhibited human skin fibroblasts and growth-arrested HT1080 cells. FIV vectors in which the U3 promoter was replaced with the cytomegalovirus promoter gave rise to over 50-fold-higher titers than FIV vectors containing the complete FIV 5′ long terminal repeat (LTR). Comparison of the transduction efficiencies of vectors containing different portions of the FIV Gag coding region indicates that at least a functional part of the FIV packaging signal (Ψ) is located within an area which includes the 5′ LTR and the first 350 bp of gag. Transduction efficiencies of vectors prepared without FIV vif and orf2 accessory gene expression did not differ substantially from those of vectors prepared with accessory gene expression in either dividing or nondividing cells. The requirement for FIV rev-RRE was, however, demonstrated by the inefficient production of vector particles in the absence of rev expression. Together, these results demonstrate the efficient transduction of nondividing cells in vitro by a multiply attenuated FIV vector and contribute to an understanding of the minimum requirements for efficient vector production and infectivity. In addition, we describe the ability of an FIV vector to deliver genes in vivo into hamster muscle tissue.
PMCID: PMC112543  PMID: 10233961
7.  Requirements for Efficient Production and Transduction of Human Immunodeficiency Virus Type 1-Based Vectors 
Journal of Virology  1999;73(3):1828-1834.
A number of human immunodeficiency type 1 (HIV-1)-based vectors have recently been shown to transduce nondividing cells in vivo as well as in vitro. However, if these vectors are to be considered for eventual clinical use, a major consideration is to reduce the probability of unintended generation of replication-competent virus. This can be achieved by eliminating viral genetic elements involved in the generation of replication-competent virus without impairing vector production. We have designed a system to transiently produce HIV-1-based vectors by using expression plasmids encoding Gag, Pol, and Tat of HIV-1 under the control of the cytomegalovirus immediate-early promoter. Our data show that the best vector yield is achieved in the presence of the Rev/Rev-responsive element (RRE) system. However, the constitutive transport element of Mason-Pfizer monkey virus can substitute for RRE and Rev at least to some extent, whereas the posttranscriptional regulatory element of human hepatitis B virus appeared to be inefficient. In addition, we show that high-titer virus preparations can be obtained in the presence of sodium butyrate, which activates the expression of both the packaging construct and the vector genome. Finally, our results suggest that efficient infectivity of vectors defective in the accessory proteins Vif, Vpr, Vpu, and Nef depends on the nature of the target cells.
PMCID: PMC104422  PMID: 9971760

Results 1-7 (7)