Biomedical subjects

Dale Woodbury

Publications and source records attributed to Dale Woodbury.

5 recordsLinked to original sources

PubMed2006

Marrow stromal cells transplanted to the adult brain are rejected by an inflammatory response and transfer donor labels to host neurons and glia.

Abstract The remarkable plasticity of marrow stromal cells (MSCs) after transplantation to models of neurological disease and injury has been described. In this report, we investigated the plasticity and long-term survival of MSCs transplanted into the normal brain. MSCs were isolated from green fluorescent protein (GFP) transgenic rats and double-labeled with 5-bromo-2-deoxyuridine (BrdU) and bis benzamide (BBZ) prior to transplantation into the adult hippocampus or striatum. Surgery elicited an immediate inflammatory response. MSC grafts were massively infiltrated by ED1-positive microglia/macrophages and surrounded by a marked astrogliosis. By 14 days, graft volume had retracted and GFP immunoreactivity was absent, indicating complete donor rejection. Consequently, MSCs did not exhibit plasticity formerly identified in other studies. However, BrdU- and BBZ-labeled cells were detected up to 12 weeks. Control transplants of nonviable MSCs demonstrated the transfer of donor labels to host cells. Unexpectedly, BrdU labeling was colocalized to host phagocytes, astrocytes, and neurons in both regions. Our results indicate that MSCs transplanted to the intact adult brain are rejected by an inflammatory response. Moreover, use of the traditional cell labels BrdU and BBZ may provide a misleading index of donor survival and differentiation after transplantation.

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PubMed2006

Adult rat bone marrow stromal cells express genes associated with dopamine neurons.

An intensive search is underway to identify candidates to replace the cells that degenerate in Parkinson's disease (PD). To date, no suitable substitute has been found. We have recently found that adult rat bone marrow stromal cells (MSCs) can be induced to assume a neuronal phenotype in vitro. These findings may have particular relevance to the treatment of PD. We now report that adult MSCs express multiple dopaminergic genes, suggesting that they are potential candidates for cell therapy. Using RT-PCR, we have examined families of genes that are associated with the development and/or survival of dopaminergic neurons. MSCs transcribe a variety of dopaminergic genes including patched and smoothened (components of the Shh receptor), Gli-1 (downstream mediator of Shh), and Otx-1, a gene associated with formation of the mesencephalon during development. Furthermore, Shh treatment elicits a 1.5-fold increase in DNA synthesis in cultured MSCs, suggesting the presence of a functional Shh receptor complex. We have also found that MSCs transcribe and translate Nurr-1, a nuclear receptor essential for the development of dopamine neurons. In addition, MSCs express a variety of growth factor receptors including the glycosyl-phosphatidylinositol-anchored ligand-binding subunit of the GDNF receptor, GFRalpha1, as well as fibroblast growth factor receptors one and four. The expression of genes that are associated with the development and survival of dopamine neurons suggests a potential role for these cells in the treatment of Parkinson's disease.

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PubMed2004

Adult bone marrow stromal cells in the embryonic brain: engraftment, migration, differentiation, and long-term survival.

We recently differentiated adult rat and human bone marrow stromal cells (MSCs) into presumptive neurons in cell culture. To determine whether the MSCs assume neuronal functions in vivo, we now characterize for the first time engraftment, migration, phenotypic expression, and long-term survival after infusion into embryonic day 15.5 (E15.5) rat ventricles in utero. By E17.5, donor cells formed discrete spheres in periventricular germinal zones, suggesting preferential sites of engraftment. The cells expressed progenitor vimentin and nestin but not mature neuronal markers. By E19.5, a subset assumed elongated migratory morphologies apposed to radial nestin-positive fibers running through the cortical white matter and plate, suggesting migration along radial glial processes. Cells remaining in germinal zones extended long, vimentin-positive fibers into the parenchyma, suggesting that the MSCs generated both migratory neurons and guiding radial glia. Consistent with this suggestion, >50% of cultured mouse MSCs expressed the neuroprecursor/radial glial protein RC2. From E19.5 to postnatal day 3, MSCs populated distant areas, including the neocortices, hippocampi, rostral migratory stream, and olfactory bulbs. Whereas donor cells confined to the subventricular zone continued to express nestin, cells in the neocortex and midbrain expressed mature neuronal markers. The donor cells survived for at least 2 months postnatally, the longest time examined. Confocal analysis revealed survival of thousands of cells per cubic millimeter in the frontal cortex and olfactory bulb at 1 month. In the cortex and bulb, 98.6 and 77.3% were NeuN (neuronal-specific nuclear protein) positive, respectively. Our observations suggest that transplanted adult MSCs differentiate in a regionally and temporally specific manner.

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PubMed2003

Marrow stromal cells, mitosis, and neuronal differentiation: stem cell and precursor functions.

To define relationships among marrow stromal cells (MSCs), multipotential progenitors, committed precursors, and derived neurons, we examined differentiation, mitosis, and apoptosis in vitro. Neural induction medium morphologically converted over 70% of MSCs to typical neurons, which expressed tau, neuronal nuclear antigen, neuron-specific enolase, and TUC-4 within 24 hours. A subset decreased fibronectin expression, consistent with mesenchymal to neuroectodermal conversion. More than 35% of differentiating neurons incorporated bromodeoxyuridine (BrdU) and divided, increasing cell number by 60%, while another subpopulation differentiated without incorporating BrdU or dividing. Inhibition of mitosis and DNA synthesis did not prevent neural differentiation, with 70% of blocked cells expressing tau and displaying neuronal morphologies. By deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay, less than 1% of cells underwent apoptosis at 36 and 72 hours, suggesting differentiation without cell-selective mechanisms. Apparently, MSCs may directly differentiate into neurons without passing through a mitotic stage, suggesting that distinctions among stem cells, progenitors, and precursors are more flexible than formerly recognized.

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PubMed2002

Adult bone marrow stromal stem cells express germline, ectodermal, endodermal, and mesodermal genes prior to neurogenesis.

Bone marrow stromal stem cells (MSCs) normally differentiate into mesenchymal derivatives but recently have also been converted into neurons, classical ectodermal cells. To begin defining underlying mechanisms, we extended our characterization of MSCs and the differentiated neurons. In addition to expected mesodermal mRNAs, populations and clonal lines of MSCs expressed germinal, endodermal, and ectodermal genes. Thus, the MSCs are apparently "multidifferentiated" in addition to being multipotent. Conversely, the differentiating neurons derived from populations and clonal lines of MSCs expressed the specific markers beta-III tubulin, tau, neurofilament-M, TOAD-64, and synaptophysin de novo. The transmitter enzymes tyrosine hydroxylase and choline acetyltransferase were localized to neuronal subpopulations. Our observations suggest that MSCs are already multidifferentiated and that neural differentiation comprises quantitative modulation of gene expression rather than simple on-off switching of neural-specific genes.

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