|03-22-2005, 11:56 PM||#1|
Join Date: Jul 2001
Location: New Brunswick, NJ, USA
Summary of literature supporting bone marrow transplant treatment of spinal cord injury
posted by cementhead
Let me review the data supporting beneficial effects of bone marrow stem cells in spinal cord injury.
1. Bone marrow has pluripotent stem cells. Woodbury, et al. (2000) and Black & Woodbury (2000) at UMDNJ in New Jersey reported that bone marrow contains cells that can make multiple types of cells including neurons, suggesting that they are stem cells. Reyes & Verfaillie (2001), Reyes, et al. (2001), and Jiang, et al. (2002a, 2002b) from the Verfaillie laboratory in Minnesota extended these findings by showing that bone marrow contains multipotent adult progenitor cells (MAPC) that produce a variety of cell types, including mesodermal, neuroectodermal, and endodermal cell types.
2. Bone marrows cell transplants improve locomotor recovery in rats and form glial cells and "guiding strands" across the injury site. Chopp, et al. (2000) transplanted bone marrow mesenchymal stem cells into spinal cords of rats at one week after injury, reporting improved locomotor recovery. Hofstetter, et al. (2002) from Darwin Prockop and Lars Olson's laboratories reported that marrow stromal cells formed guiding strands in injured spinal cords and promoted recovery. Koshizuka, et al. (2004) from Chiba University reported that transplanted hematopoietic bone marrow stem cells in mice improved function recovery and differentiated into a number of cells including astrocytes, oligodendroglia, and neural precursors but not neurons.
3. Bone marrow cell transplants facilitate remyelination of the spinal cord. In 2001, Sasaki, et al. (2001), Kocsis, et al. (2001), Akiyama, et al. (2002) from the Kocsis laboratory and also in the Univeristy of Hokkaido found that bone marrow cells remyelinated spinal axons that had been demyelinated by x-radiation, in a manner similar to Schwann cells and neural precursor cells (Kocsis, et al., 2004).
4. Bone marrow stem cells appear to be neuroprotective when transplanted shortly after injury. Ohta, et al. (2004) infused bone marrow stromal cells into the cerebrospinal fluid of rats after contusion injury. The cells migrated to the injury site and attached to the spinal surface without invading into the cord. However, the rats showed better locomotor recovery and smaller lesion cavities. Ankeny, et al. (2004) found that bone marrow stem cells reduced tissue damage after contusive injuries of the spinal cord.
5. Bone marrow stem cells also promote regeneration in injured rat spinal cords. Wu, et al. (2003) found that bone marrow cells, when transplanted with fetal neural stem cells, enhanced tissue repair and regeneration in injured spinal cords. Lu, et al. (2004) showed that combination therapy with neurotrophins and cAMP promoted axonal regeneration in injured spinal cords. Lu, et al. (2005) showed that bone marrow stem cells supported modest growth of host sensory and motor axons in the spinal cord but did not become neurons in the spinal cord. Genetic modification of the cells with BDNF (brain-derived neurotrophic factor) markedly enhanced growth of axons but did not improve functional recovery in contused spinal cords. Neuhuber, et al., (2005) implanted human bone marrow mesenchymal stem cells into rat spinal cords and found that the beneficial effects of the cells varied and depended on neurotrophic factors expressed by the cells.
In summary, a number of animal studies suggest strongly that a variety of bone marrow stem cells improve recovery probably by protecting the spinal cord, remyelinating the spinal cord, and regenerating the spinal cord. Based on these studies, several groups have transplanted bone marrow stem cells into humans with chronic spinal cord injury. Although the results of these trials have not yet been reported, preliminary reports suggest that they modestly improve function. Dr. Tarcisio transplanted bone marrow autografts by injecting them into the arteries of the spinal cords of 30 patients and reported improvements in somatosensory evoked potentials. In Zhengzhou, Dr. Yong-fu Zhang has transplanted bone marrow stem cell autografts into as many as 180 patients with spinal cord injury.
References Cited (in alphabetical order)
Akiyama Y, Radtke C, Honmou O and Kocsis JD (2002). Remyelination of the spinal cord following intravenous delivery of bone marrow cells. Glia 39: 229-36. Bone marrow contains a population of pluripotent cells that can differentiate into a variety of cell lineages, including neural cells. When injected directly into the demyelinated spinal cord they can elicit remyelination. Recent work has shown that following systemic delivery of bone marrow cells functional improvement occurs in contusive spinal cord injury and stroke models in rat. We report here that secondary to intravenous introduction of an acutely isolated bone marrow cell fraction (mononuclear fraction) from adult rat femoral bones separated on a density gradient, ultrastructurally defined remyelination occurs throughout a focal demyelinated spinal cord lesion. The anatomical pattern of remyelination was characteristic of both oligodendrocyte and Schwann cell myelination; conduction velocity improved in the remyelinated axons. When the injected bone marrow cells were transfected to express LacZ, beta-galactosidase reaction product was observed in some myelin-forming cells in the spinal cord. Intravenous injection of other myelin-forming cells (Schwann cells and olfactory ensheathing cells) or the residual cell fraction of the gradient did not result in remyelination, suggesting that remyelination was specific to the delivery of the mononuclear fraction. While the precise mechanism of the repair, myelination by the bone marrow cells or facilitation of an endogenous repair process, cannot be fully determined, the results demonstrate an unprecedented level of myelin repair by systemic delivery of the mononuclear cells. Department of Neurology, Yale University School of Medicine, New Haven, Connecticut 06516, USA.
Ankeny DP, McTigue DM and Jakeman LB (2004). Bone marrow transplants provide tissue protection and directional guidance for axons after contusive spinal cord injury in rats. Exp Neurol 190: 17-31. Contusive spinal cord injury (SCI) produces large fluid-, debris- and inflammatory cell-filled cystic cavities that lack structure to support significant axonal regeneration. The recent discovery of stem cells capable of generating central nervous system (CNS) tissues, coupled with success in neurotransplantation strategies, has renewed hope that repair and recovery from CNS trauma is possible. Based on results from several studies using bone marrow stromal cells (MSCs) to promote CNS repair, we transplanted MSCs into the rat SCI lesion cavity to further investigate their effects on functional recovery, lesion morphology, and axonal growth. We found that transplanted MSCs induced hindlimb airstepping--a spontaneous locomotor movement associated with activation of the stepping control circuitry--but did not alter the time course or extent of overground locomotor recovery. Using stereological techniques to describe spinal cord anatomy, we show that MSC transplants occupied the lesion cavity and were associated with preservation of host tissue and white matter (myelin), demonstrating that these cells exert neuroprotective effects. The tissue matrix formed by MSC grafts supported greater axonal growth than that found in specimens without grafts. Moreover, uniform random sampling of axon profiles revealed that the majority of neurites in MSC grafts were oriented with their long axis parallel to that of the spinal cord, suggesting longitudinally directed growth. Together, these studies support further investigation of marrow stromal cells as a potential SCI repair strategy. Department of Physiology and Cell Biology, The Ohio State University, 333 West 10th Avenue, Columbus, OH 43210, USA. Ankeny.email@example.com
Black IB and Woodbury D (2001). Adult rat and human bone marrow stromal stem cells differentiate into neurons. Blood Cells Mol Dis 27: 632-6. Department of Neuroscience and Cell Biology, UMDNJ-Robert Wood Johnson Medical School, 675 Hoes Lane, CABM 342, Piscataway, NJ 08854, USA. firstname.lastname@example.org
Chopp M, Zhang XH, Li Y, Wang L, Chen J, Lu D, Lu M and Rosenblum M (2000). Spinal cord injury in rat: treatment with bone marrow stromal cell transplantation. Neuroreport 11: 3001-5. We tested the hypothesis that transplantation of bone marrow stromal cells (MSCs) into the spinal cord after a contusion injury promotes functional outcome. Rats (n = 31) were subjected to a weight driven implant injury. MSCs or phosphate buffered saline was injected into the spinal cord 1 week after injury. Sections of tissue were analyzed by double-labeled immunohistochemistry for MSC identification. Functional outcome measurements using the Basso-Beattie-Bresnehan score were performed weekly to 5 weeks post-injury. The data indicate significant improvement in functional outcome in animals treated with MSC transplantation compared to control animals. Scattered cells derived from MSCs expressed neural protein markers. These data suggest that transplantation of MSCs may have a therapeutic role after spinal cord injury. Department of Neurology, Henry Ford Health Sciences Center, Detroit, MI 48202, USA.
Hofstetter CP, Schwarz EJ, Hess D, Widenfalk J, El Manira A, Prockop DJ and Olson L (2002). Marrow stromal cells form guiding strands in the injured spinal cord and promote recovery. Proc Natl Acad Sci U S A 99: 2199-204. Marrow stromal cells (MSC) can be expanded rapidly in vitro and differentiated into multiple mesodermal cell types. In addition, differentiation into neuron-like cells expressing markers typical for mature neurons has been reported. To analyze whether such cells, exposed to differentiation media, could develop electrophysiological properties characteristic of neurons, we performed whole-cell recordings. Neuron-like MSC, however, lacked voltage-gated ion channels necessary for generation of action potentials. We then delivered MSC into the injured spinal cord to study the fate of transplanted MSC and possible effects on functional outcome in animals rendered paraplegic. MSC given 1 week after injury led to significantly larger numbers of surviving cells than immediate treatment and significant improvements of gait. Histology 5 weeks after spinal cord injury revealed that MSC were tightly associated with longitudinally arranged immature astrocytes and formed bundles bridging the epicenter of the injury. Robust bundles of neurofilament-positive fibers and some 5-hydroxytryptamine-positive fibers were found mainly at the interface between graft and scar tissue. MSC constitute an easily accessible, easily expandable source of cells that may prove useful in the establishment of spinal cord repair protocols. Department of Neuroscience, Karolinska Institutet, S-171 77 Stockholm, Sweden.
Jiang Y, Vaessen B, Lenvik T, Blackstad M, Reyes M and Verfaillie CM (2002a). Multipotent progenitor cells can be isolated from postnatal murine bone marrow, muscle, and brain. Exp Hematol 30: 896-904. OBJECTIVE: Recent studies have shown that cells from bone marrow (BM), muscle, and brain may have greater plasticity than previously known. We have identified multipotent adult progenitor cells (MAPC) in postnatal human and rodent BM that copurify with mesenchymal stem cells (MSC). BM MAPC proliferate without senescence and differentiate into mesodermal, neuroectodermal, and endodermal cell types. We hypothesized that cells with characteristics similar to BM MAPC can be selected and cultured from tissues other than BM. MATERIALS AND METHODS: BM, whole brain, and whole muscle tissue was obtained from mice. Cells were plated on Dulbecco modified Eagle medium supplemented with 2% fetal calf serum and 10 ng/mL epidermal growth factor (EGF), 10 ng/mL platelet-derived growth factor (PDGF-BB), and 1000 units/mL leukemia inhibitory factor (LIF) for more than 6 months. Cells were maintained between 0.5 and 1.5 x 10(3) cells/cm(2). At variable time points, we tested cell phenotype by FACS and evaluated their differentiation into endothelial cells, neuroectodermal cells, and endodermal cells in vitro. We also compared the expressed gene profile in BM, muscle, and brain MAPC by Affimetrix gene array analysis. RESULTS: Cells could be cultured from BM, muscle, and brain that proliferated for more than 70 population doublings (PDs) and were negative for CD44, CD45, major histocompatibility complex class I and II, and c-kit. Cells from the three tissues differentiated to cells with morphologic and phenotypic characteristics of endothelium, neurons, glia, and hepatocytes. The expressed gene profile of cells derived from the three tissues was identical (r(2) > 0.975). CONCLUSIONS: This study shows that cells with MAPC characteristics can be isolated not only from BM, but also from brain and muscle tissue. Whether MAPC originally derived from BM are circulating or all organs contain stem cells with MAPC characteristics currently is being studied. Presence of MAPC in multiple tissues may help explain the "plasticity" found in multiple adult tissues. Stem Cell Institute, Department of Medicine, University of Minnesota Medical School, Minneapolis 55455, USA.
Jiang Y, Jahagirdar BN, Reinhardt RL, Schwartz RE, Keene CD, Ortiz-Gonzalez XR, Reyes M, Lenvik T, Lund T, Blackstad M, Du J, Aldrich S, Lisberg A, Low WC, Largaespada DA and Verfaillie CM (2002b). Pluripotency of mesenchymal stem cells derived from adult marrow. Nature 418: 41-9. We report here that cells co-purifying with mesenchymal stem cells--termed here multipotent adult progenitor cells or MAPCs--differentiate, at the single cell level, not only into mesenchymal cells, but also cells with visceral mesoderm, neuroectoderm and endoderm characteristics in vitro. When injected into an early blastocyst, single MAPCs contribute to most, if not all, somatic cell types. On transplantation into a non-irradiated host, MAPCs engraft and differentiate to the haematopoietic lineage, in addition to the epithelium of liver, lung and gut. Engraftment in the haematopoietic system as well as the gastrointestinal tract is increased when MAPCs are transplanted in a minimally irradiated host. As MAPCs proliferate extensively without obvious senescence or loss of differentiation potential, they may be an ideal cell source for therapy of inherited or degenerative diseases. Stem Cell Institute, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA.
Kocsis JD, Akiyama Y, Lankford KL and Radtke C (2002). Cell transplantation of peripheral-myelin-forming cells to repair the injured spinal cord. J Rehabil Res Dev 39: 287-98. Much excitement has been generated by recent work showing that a variety of myelin-forming cell types can elicit remyelination and facilitate axonal regeneration in animal models of demyelination and axonal transection. These cells include peripheral-myelin-forming cells, such as Schwann cells and olfactory ensheathing cells. In addition, progenitor cells derived from the subventricular zone of the brain and from bone marrow (BM) can form myelin when transplanted into demyelinated lesions in rodents. Here, we discuss recent findings that examine the remyelination potential of transplantation of peripheral-myelin-forming cells and progenitor cells derived from brain and bone marrow. Better understanding of the repair potential of these cells in animal models may offer exciting opportunities to develop cells that may be used in future clinical studies. Department of Neurology, Yale University School of Medicine, New Haven, CT 06516, USA. email@example.com
Kocsis JD, Akiyama Y and Radtke C (2004). Neural precursors as a cell source to repair the demyelinated spinal cord. J Neurotrauma 21: 441-9. Schwann cells and neural precursor cells derived from adult human brain (subventricular zone) and from bone marrow were studied anatomically and physiologically after transplantation into the demyelinated rat spinal cord. All cell types formed myelin and restored conduction velocity. Following transection of the dorsal funiculus, Schwann cells and olfactory ensheathing cells facilitated axonal regeneration and restoration of conduction across the lesion site. There is discussion on the challenges of cell type selection and preparation for a potential clinical cell therapy study in human demyelinating diseases. Department of Neurology, Yale University School of Medicine, New Haven,VA Medical Center, West Haven, Connecticut 06516, USA. firstname.lastname@example.org
Koshizuka S, Okada S, Okawa A, Koda M, Murasawa M, Hashimoto M, Kamada T, Yoshinaga K, Murakami M, Moriya H and Yamazaki M (2004). Transplanted hematopoietic stem cells from bone marrow differentiate into neural lineage cells and promote functional recovery after spinal cord injury in mice. J Neuropathol Exp Neurol 63: 64-72. Recovery in central nervous system disorders is hindered by the limited ability of the vertebrate central nervous system to regenerate lost cells, replace damaged myelin, and re-establish functional neural connections. Cell transplantation to repair central nervous system disorders is an active area of research, with the goal of reducing functional deficits. Recent animal studies showed that cells of the hematopoietic stem cell (HSC) fraction of bone marrow transdifferentiated into various nonhematopoietic cell lineages. We employed a mouse model of spinal cord injury and directly transplanted HSCs into the spinal cord 1 week after injury. We evaluated functional recovery using the hindlimb motor function score weekly for 5 weeks after transplantation. The data demonstrated a significant improvement in the functional outcome of mice transplanted with hematopoietic stem cells compared with control mice in which only medium was injected. Fluorescent in situ hybridization for the Y chromosome and double immunohistochemistry showed that transplanted cells survived 5 weeks after transplantation and expressed specific markers for astrocytes, oligodendrocytes, and neural precursors, but not for neurons. These results suggest that transplantation of HSCs from bone marrow is an effective strategy for the treatment of spinal cord injury. Department of Orthopaedic Surgery, Chiba University, Graduate School of Medicine, Chiba, Japan. email@example.com
Kamada T, Koda M, Dezawa M, Yoshinaga K, Hashimoto M, Koshizuka S, Nishio Y, Moriya H and Yamazaki M (2005). Transplantation of bone marrow stromal cell-derived Schwann cells promotes axonal regeneration and functional recovery after complete transection of adult rat spinal cord. J Neuropathol Exp Neurol 64: 37-45. The aim of this study was to evaluate whether transplantation of Schwann cells derived from bone marrow stromal cells (BMSC-SCs) promotes axonal regeneration and functional recovery in completely transected spinal cord in adult rats. Bone marrow stromal cells (BMSCs) were induced to differentiate into Schwann cells in vitro. A 4-mm segment of rat spinal cord was removed completely at the T7 level. An ultra-filtration membrane tube, filled with a mixture of Matrigel (MG) and BMSC-SCs (BMSC-SC group) or Matrigel alone (MG group), was grafted into the gap. In the BMSC-SC group, the number of neurofilament- and tyrosine hydroxylase-immunoreactive nerve fibers was significantly higher compared to the MG group, although 5-hydroxytryptamine- or calcitonin gene-related peptide-immunoreactive fibers were rarely detectable in both groups. In the BMSC-SC group, significant recovery of the hindlimb function was recognized, which was abolished by retransection of the graft 6 weeks after transplantation. These results demonstrate that transplantation of BMSC-SCs promotes axonal regeneration of lesioned spinal cord, resulting in recovery of hindlimb function in rats. Transplantation of BMSC-SCs is a potentially useful treatment for spinal cord injury. Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan.
Lu P, Jones LL and Tuszynski MH (2005). BDNF-expressing marrow stromal cells support extensive axonal growth at sites of spinal cord injury. Exp Neurol 191: 344-60. Bone marrow stromal cells (MSCs) constitute a heterogeneous cell layer in the bone marrow, supporting the growth and differentiation of hematopoietic stem cells. Recently, it has been reported that MSCs harbor pluripotent stem cells capable of neural differentiation and that simple treatment of MSCs with chemical inducing agents leads to their rapid transdifferentiation into neural cells. We examined whether native or neurally induced MSCs would reconstitute an axonal growth-promoting milieu after cervical spinal cord injury (SCI), and whether such cells could act as vehicles of growth factor gene delivery to further augment axonal growth. One month after grafting to cystic sites of SCI, native MSCs supported modest growth of host sensory and motor axons. Cells "neurally" induced in vitro did not sustain a neural phenotype in vivo and supported host axonal growth to a degree equal to native MSCs. Transduction of MSCs to overexpress brain-derived neurotrophic factor (BDNF) resulted in a significant increase in the extent and diversity of host axonal growth, enhancing the growth of host serotonergic, coerulospinal, and dorsal column sensory axons. Measurement of neurotrophin production from implanted cells in the lesion site revealed that the grafts naturally contain nerve growth factor (NGF) and neurotrophin-3 (NT-3), and that transduction with BDNF markedly raises levels of BDNF production. Despite the extensive nature of host axonal penetration into the lesion site, functional recovery was not observed on a tape removal or rope-walking task. Thus, MSCs can support host axonal growth after spinal cord injury and are suitable cell types for ex vivo gene delivery. Combination therapy with other experimental approaches will likely be required to achieve axonal growth beyond the lesion site and functional recovery. Department of Neurosciences and Center for Neural Repair, University of California at San Diego, La Jolla, CA 92093-0626, USA.
Lu P, Yang H, Jones LL, Filbin MT and Tuszynski MH (2004). Combinatorial therapy with neurotrophins and cAMP promotes axonal regeneration beyond sites of spinal cord injury. J Neurosci 24: 6402-9. Previous attempts to promote regeneration after spinal cord injury have succeeded in stimulating axonal growth into or around lesion sites but rarely beyond them. We tested whether a combinatorial approach of stimulating the neuronal cell body with cAMP and the injured axon with neurotrophins would propel axonal growth into and beyond sites of spinal cord injury. A preconditioning stimulus to sensory neuronal cell bodies was delivered by injecting cAMP into the L4 dorsal root ganglion, and a postinjury stimulus to the injured axon was administered by injecting neurotrophin-3 (NT-3) within and beyond a cervical spinal cord lesion site grafted with autologous bone marrow stromal cells. One to 3 months later, long-projecting dorsal-column sensory axons regenerated into and beyond the lesion. Regeneration beyond the lesion did not occur after treatment with cAMP or NT-3 alone. Thus, clear axonal regeneration beyond spinal cord injury sites can be achieved by combinatorial approaches that stimulate both the neuronal soma and the axon, representing a major advance in strategies to enhance spinal cord repair. Department of Neurosciences, University of California at San Diego, La Jolla, California 92093-0626, USA.
Neuhuber B, Timothy Himes B, Shumsky JS, Gallo G and Fischer I (2005). Axon growth and recovery of function supported by human bone marrow stromal cells in the injured spinal cord exhibit donor variations. Brain Res 1035: 73-85. Bone marrow stromal cells (MSC) are non-hematopoietic support cells that can be easily derived from bone marrow aspirates. Human MSC are clinically attractive because they can be expanded to large numbers in culture and reintroduced into patients as autografts or allografts. We grafted human MSC derived from aspirates of four different donors into a subtotal cervical hemisection in adult female rats and found that cells integrated well into the injury site, with little migration away from the graft. Immunocytochemical analysis demonstrated robust axonal growth through the grafts of animals treated with MSC, suggesting that MSC support axonal growth after spinal cord injury (SCI). However, the amount of axon growth through the graft site varied considerably between groups of animals treated with different MSC lots, suggesting that efficacy may be donor-dependent. Similarly, a battery of behavioral tests showed partial recovery in some treatment groups but not others. Using ELISA, we found variations in secretion patterns of selected growth factors and cytokines between different MSC lots. In a dorsal root ganglion explant culture system, we tested efficacy of conditioned medium from three donors and found that average axon lengths increased for all groups compared to control. These results suggest that human MSC produce factors important for mediating axon outgrowth and recovery after SCI but that MSC lots from different donors vary considerably. To qualify MSC lots for future clinical application, such notable differences in donor or lot-lot efficacy highlight the need for establishing adequate characterization, including the development of relevant efficacy assays. Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA.
Newman MB, Davis CD, Kuzmin-Nichols N and Sanberg PR (2003). Human umbilical cord blood (HUCB) cells for central nervous system repair. Neurotox Res 5: 355-68. Cellular therapy is a compelling and potential treatment for certain neurological and neurodegenerative diseases as well as a viable treatment for acute injury to the spinal cord and brain. The hematopoietic system offers alternative sources for stem cells compared to those of fetal or embryonic origin. Bone marrow stromal and umbilical cord cells have been used in pre-clinical models of brain injury, directed to differentiate into neural phenotypes, and have been related to functional recovery after engraftment in central nervous system (CNS) injury models. This paper reviews the advantages, utilization and progress of human umbilical cord blood (HUCB) cells in the neural cell transplantation and repair field. Center of Excellence for Aging and Brain Repair, Departments of Neurosurgery, Psychology, Psychiatry, Neurology, Pathology and Pharmacology, University of South Florida, College of Medicine, Tampa FL 33612, USA.
Ohta M, Suzuki Y, Noda T, Ejiri Y, Dezawa M, Kataoka K, Chou H, Ishikawa N, Matsumoto N, Iwashita Y, Mizuta E, Kuno S and Ide C (2004). Bone marrow stromal cells infused into the cerebrospinal fluid promote functional recovery of the injured rat spinal cord with reduced cavity formation. Exp Neurol 187: 266-78. The effects of bone marrow stromal cells (BMSCs) on the repair of injured spinal cord and on the behavioral improvement were studied in the rat. The spinal cord was injured by contusion using a weight-drop at the level of T8-9, and the BMSCs from the bone marrow of the same strain were infused into the cerebrospinal fluid (CSF) through the 4th ventricle. BMSCs were conveyed through the CSF to the spinal cord, where most BMSCs attached to the spinal surface although a few invaded the lesion. The BBB score was higher, and the cavity volume was smaller in the rats with transplantation than in the control rats. Transplanted cells gradually decreased in number and disappeared from the spinal cord 3 weeks after injection. The medium supplemented by CSF (250 microl in 3 ml medium) harvested from the rats in which BMSCs had been injected 2 days previously promoted the neurosphere cells to adhere to the culture dish and to spread into the periphery. These results suggest that BMSCs can exert effects by producing some trophic factors into the CSF or by contacting with host spinal tissues on the reduction of cavities and on the improvement of behavioral function in the rat. Considering that BMSCs can be used for autologous transplantation, and that the CSF infusion of transplants imposes a minimal burden on patients, the results of the present study are important and promising for the clinical use of BMSCs in spinal cord injury treatment. Department of Plastic and Reconstructive Surgery, Kyoto University Graduate School of Medicine, Shogoin, Sakyo-Ku, Kyoto 606-8507, Japan.
Reyes M and Verfaillie CM (2001). Characterization of multipotent adult progenitor cells, a subpopulation of mesenchymal stem cells. Ann N Y Acad Sci 938: 231-3; discussion 233-5. Mesenchymal stem cells were isolated and a subpopulation of cells--multipotent adult progenitor cells--were identified that have the potential for multilineage differentiation. Their ability to engraft and differentiate in vivo is under investigation. Stem Cell Institute and Department of Medicine, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Sasaki M, Honmou O, Akiyama Y, Uede T, Hashi K and Kocsis JD (2001). Transplantation of an acutely isolated bone marrow fraction repairs demyelinated adult rat spinal cord axons. Glia 35: 26-34. The potential of bone marrow cells to differentiate into myelin-forming cells and to repair the demyelinated rat spinal cord in vivo was studied using cell transplantation techniques. The dorsal funiculus of the spinal cord was demyelinated by x-irradiation treatment, followed by microinjection of ethidium bromide. Suspensions of a bone marrow cell fraction acutely isolated from femoral bones in LacZ transgenic mice were prepared by centrifugation on a density gradient (Ficoll-Paque) to remove erythrocytes, platelets, and debris. The isolated cell fraction contained hematopoietic and nonhematopoietic stem and precursor cells and lymphocytes. The cells were transplanted into the demyelinated dorsal column lesions of immunosuppressed rats. An intense blue beta-galactosidase reaction was observed in the transplantation zone. The genetically labeled bone marrow cells remyelinated the spinal cord with predominately a peripheral pattern of myelination reminiscent of Schwann cell myelination. Transplantation of CD34(+) hematopoietic stem cells survived in the lesion, but did not form myelin. These results indicate that bone marrow cells can differentiate in vivo into myelin-forming cells and repair demyelinated CNS. Department of Neurosurgery, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan.
Woodbury D, Schwarz EJ, Prockop DJ and Black IB (2000). Adult rat and human bone marrow stromal cells differentiate into neurons. J Neurosci Res 61: 364-70. Bone marrow stromal cells exhibit multiple traits of a stem cell population. They can be greatly expanded in vitro and induced to differentiate into multiple mesenchymal cell types. However, differentiation to non-mesenchymal fates has not been demonstrated. Here, adult rat stromal cells were expanded as undifferentiated cells in culture for more than 20 passages, indicating their proliferative capacity. A simple treatment protocol induced the stromal cells to exhibit a neuronal phenotype, expressing neuron-specific enolase, NeuN, neurofilament-M, and tau. With an optimal differentiation protocol, almost 80% of the cells expressed NSE and NF-M. The refractile cell bodies extended long processes terminating in typical growth cones and filopodia. The differentiating cells expressed nestin, characteristic of neuronal precursor stem cells, at 5 hr, but the trait was undetectable at 6 days. In contrast, expression of trkA, the nerve growth factor receptor, persisted from 5 hr through 6 days. Clonal cell lines, established from single cells, proliferated, yielding both undifferentiated and neuronal cells. Human marrow stromal cells subjected to this protocol also differentiated into neurons. Consequently, adult marrow stromal cells can be induced to overcome their mesenchymal commitment and may constitute an abundant and accessible cellular reservoir for the treatment of a variety of neurologic diseases. Department of Neuroscience and Cell Biology, UMDNJ-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA. firstname.lastname@example.org
Wu S, Suzuki Y, Ejiri Y, Noda T, Bai H, Kitada M, Kataoka K, Ohta M, Chou H and Ide C (2003). Bone marrow stromal cells enhance differentiation of cocultured neurosphere cells and promote regeneration of injured spinal cord. J Neurosci Res 72: 343-51. Transplantation of bone marrow stromal cells (MSCs) has been regarded as a potential approach for promoting nerve regeneration. In the present study, we investigated the influence of MSCs on spinal cord neurosphere cells in vitro and on the regeneration of injured spinal cord in vivo by grafting. MSCs from adult rats were cocultured with fetal spinal cord-derived neurosphere cells by either cell mixing or making monolayered-feeder cultures. In the mixed cell cultures, neuroshpere cells were stimulated to develop extensive processes. In the monolayered-feeder cultures, numerous processes from neurosphere cells appeared to be attracted to MSCs. In an in vivo experiment, grafted MSCs promoted the regeneration of injured spinal cord by enhancing tissue repair of the lesion, leaving apparently smaller cavities than in controls. Although the number of grafted MSCs gradually decreased, some treated animals showed remarkable functional recovery. These results suggest that MSCs might have profound effects on the differentiation of neurosphere cells and be able to promote regeneration of the spinal cord by means of grafting. Department of Plastic and Reconstructive Surgery, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto, Japan.