The devastating effects of spinal cord injury are due to the death of neurons and to the failure of the axons of surviving neurons to regenerate through the inhospitable environment created by the injury. The proposed experiments will test whether novel cellular and molecular strategies of repair will promote regeneration leading to locomotor and sensory recovery in well-characterized models of spinal cord injury in adult rats. In preliminary studies we have prepared retrovirus and recombinant adenovirus constructs of neurotrophins and shown that intraspinal transplants of fibroblasts genetically modified to express BDNF promote regeneration of rubrospinal axons that contribute to locomotor recovery. We have also used intraspinal injections of plasmid constructs and recombinant adenovirus to administer genes to spinal and supraspinal neurons that can enhance their survival and regeneration after axotomy. In the present experiments we will use as transplants multipotential neural stem cells isolated from embryonic rat spinal cord. These cells are very promising because of their capacities for self- renewal, differentiation into neurons and glia and genetic modification. We will genetically modify these cells to express neurotrophin factors BDNF and NT3 or adhesion protein L1, and in addition deliver the antiapoptotic gene Bcl-2 by plasmid injections or adenovirus. We propose that this combination of treatments will enhance neuron survival and axon regeneration and promote the recovery of locomotor and sensory function as measured by quantitative tests. In the first series of experiments we will test the idea that engineered neural stem cells transplanted into a unilateral cervical hemisection lesion will integrate with the injured host and supply factors that will rescue axotomized spinal and supraspinal neurons, promote regeneration of their axons and enhance recovery. In the second series of experiments we will test the idea that the best strategy of combined treatments will stimulate regeneration of descending pathways and recovery of hindlimb function after spinal cord transection, a model for complete spinal cord injury in humans in which results of anatomical and behavioral studies are unambiguous. The results of these experiments will contribute to developing an effective strategy for promoting neuron survival and axon regeneration that will enhance functional recovery after spinal cord injury.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS037515-04
Application #
6613426
Study Section
Special Emphasis Panel (ZRG1-MDCN-7 (01))
Program Officer
Chiu, Arlene Y
Project Start
2000-07-31
Project End
2006-06-30
Budget Start
2003-07-01
Budget End
2006-06-30
Support Year
4
Fiscal Year
2003
Total Cost
$254,439
Indirect Cost
Name
Drexel University
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
002604817
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
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Lepore, A C; Neuhuber, B; Connors, T M et al. (2006) Long-term fate of neural precursor cells following transplantation into developing and adult CNS. Neuroscience 139:513-30
Lepore, A C; Walczak, P; Rao, M S et al. (2006) MR imaging of lineage-restricted neural precursors following transplantation into the adult spinal cord. Exp Neurol 201:49-59
Lepore, A C; Fischer, I (2005) Lineage-restricted neural precursors survive, migrate, and differentiate following transplantation into the injured adult spinal cord. Exp Neurol 194:230-42
Mitsui, Takahiko; Shumsky, Jed S; Lepore, Angelo C et al. (2005) Transplantation of neuronal and glial restricted precursors into contused spinal cord improves bladder and motor functions, decreases thermal hypersensitivity, and modifies intraspinal circuitry. J Neurosci 25:9624-36
Lepore, Angelo C; Bakshi, Ajay; Swanger, Sharon A et al. (2005) Neural precursor cells can be delivered into the injured cervical spinal cord by intrathecal injection at the lumbar cord. Brain Res 1045:206-16
Lepore, Angelo C; Han, Steven S W; Tyler-Polsz, Carla J et al. (2004) Differential fate of multipotent and lineage-restricted neural precursors following transplantation into the adult CNS. Neuron Glia Biol 1:113-126
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