Alison E. Willing - US grants

Sertoli cells are post-mitotic cells originating in the testes. They express and secrete many trophic, nutritive and regulatory proteins that are able to provide trophic and immunologic support for the developing germ cell. These characteristics make them an ideal cell candidate for an adjunct to traditional neural transplantation for neurodegenerative diseases such as Parkinson's disease. This is a novel therapeutic approach that through trophic and immune support could increase the survival of transplanted neurons and decrease the need for long-term treatment with immunosuppressants. This Phase I research program proposes to determine the source of the most efficacious cells using in vitro screening assays, determine the Sertoli to neuron ratio that produces optimal neuronal survival through completion of a thorough in vivo dose-response relationship, and determine whether these cells continue to provide immune protection when grafted across species. The success of these studies in an animal model of Parkinson's disease has important implications for the therapeutic potential of these cells as graft facilitators or as the vehicle for long-term local delivery of a trophic cocktail in other neurodegenerative diseases. PROPOSED COMMERCIAL APPLICATIONS: Neural transplantation has the potential to reverse progressive degeneration in diseases such as PD, Motor Neuron Disease, Stroke. However, neuronal survival is poor and a host-generated immune response to the transplanted cells may further destroy the graft. Sertoli cells provide a novel, naturally-occurring technology to enhance neuronal survival, provide localized immunosuppression without the health risks of long-term systemic suppression and possibly decrease disease symptoms beyond currently attainable levels.

The normal aging process leads to a variety of changes in the central nervous system that underlie alterations in learning and memory as well as balance coordination. In addition, neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD), which are diseases of the aged, lead to significant morbidity and mortality. To date the pharmacological approaches to treatments of these diseases and normal aging related declines in learning and memory have been of varying success and no treatment stops the disease progression. The potential for therapeutic intervention with multipotent stem cells from adult tissues such as human umbilical cord blood (human UCB or HUCB) holds promise, yet has not been fully examined. We have chosen HUCB as it is a rich source of immature progenitor cells and is readily available. In this proposal we will study the developmental potential of HUCB cells using a well characterized model system of transplantation into the subventricular zone (SVZ) and following the cells normal migratory path to the olfactory bulb. One question that remains unanswered is how the age of the recipient alters the capacity of HUCB progenitors to develop into appropriate neural cell types. We will examine this by transplanting HUCB progenitors into rats of 6, 16, and 24 months of age and follow the fate of the transplanted HUCB cells. A second critical question is whether exogenous growth and neurotrophic factors will increase the differentiation of HUCB cells into distinct neural phenotypes and if these neuralized HUCB cells will be more (or less) successful when transplanted into the SVZ of various aged rat hosts. Finally, as there are progressive changes in learning and memory with age a critical area to examine is whether HUCB therapy can produce a functional improvement on learning and memory tasks in the aged rats. To address this question we will treat aged rats with HUCB cells and follow their performance on a test of working memory, the 12 arm radial arm water maze.

[unreadable] DESCRIPTION (provided by applicant): Cerebrovascular disease is the third leading cause of morbidity and mortality in the United States. As the population ages, it will be even more pressing to develop effective treatment options that can not only increase survival, but decrease disability. In a rat model of stroke (the middle cerebral artery occlusion or MCAO) we found that intravenously (iv) administering the mononuclear fraction from human umbilical cord blood (HUCB) enhances motor functions. In this proposal we will explore how the administration of this population of cells may induce recovery and decrease anatomical damage induced by MCAO through direct neuroprotective and anti-inflammatory mechanisms. In Aim 1 we will characterize how iv HUCB cells modify the underlying pathology and inflammation of the MCAO when administered 24 hours to 7 days after the MCAO using markers of inflammation, neuronal death, neurosurvival, and apoptosis. In Aim 2, we will identify the specific subpopulation of the HUCB cells that is instrumental in inducing behavioral and anatomical recovery. This will be accomplished using fluorescent activated cell sorting (FACS) to enrich T cell, B Cell, monocyte and "stem" cell fractions for transplantation into a stroked rat. Endpoint measures in these studies will include performance on a battery of motor tests and infarct volume. Aim 3 proposes a series of in vitro studies to examine whether the HUCB cells modify the inflammatory response to the MCAO through direct interactions with neural cell popultions. Cell culture assays using neuronal, astrocytic, oligodendrocytes or microglia will be conducted to identify direct interactions and the molecular signals that mediate survival, cytokine expression and NF-kappaB binding activity in response to hypoxia/reoxygenation. In Aim 4 we will use microarray technology to identify neural repair/survival genes that are up-regulated by HUCB treatment of neuronal cultures. All microarray experiments will be verified with western blots and immunohistochemistry. The studies proposed here will increase our understanding of the neuroprotective and anti-inflammatory mechanisms underlying the recovery from stroke induced by HUCB cell transplantation and may also identify other potential targets in stroke for development of treatment options. The ultimate goal of this research program is to develop an innovative HUCB cell based therapy into a viable clinical option for transplantation in neurodegenerative disease and brain injury. [unreadable] [unreadable] [unreadable]