|ognizant Communication Corporation|
The Regenerative Medicine Journal
VOLUME 18, NUMBER 7, 2009
Cell Transplantation, Vol. 18, pp. 691-693, 2009
0963-6897/09 $90.00 + 00
Copyright © 2009 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.
Who's in Favor of Translational Cell Therapy for Stroke: STEPS Forward Please?
Michael Chopp,1 Gary K. Steinberg,2 Douglas Kondziolka,3 Mei Lu,1 Tonya M. Bliss,2 Yi Li,1 David C. Hess,4 and Cesario V. Borlongan4,5
1Department of Neurology, Henry Ford Hospital, Detroit, MI,
2Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
3Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA
4Department of Neurology, Medical College of Georgia, Augusta, GA, USA
5Department of Neurosurgery, University of South Florida, Tampa, FL, USA
A consortium of translational stem cell and stroke experts from multiple academic institutes and biotechnology companies, under the guidance of the government (FDA/NIH), is missing. Here, we build a case for the establishment of this consortium if cell therapy for stroke is to advance from the laboratory to the clinic.
Key words: Stem cell transplantation; Tissue regeneration; Cellular therapy; Clinical translation
Address correspondence to Cesar V. Borlongan, Ph.D., Department of Neurosurgery, University of South Florida, Tampa, FL 33612, USA. Tel: 813-974-3988; Fax: 813-974-3078; E-mail: firstname.lastname@example.org
Cell-Based Therapy for Heart Failure: Skeletal Myoblasts
Monika Seidel, Aleksandra Borczynska, Natalia Rozwadowska, and Maciej Kurpisz
Institute of Human Genetics, Polish Academy of Sciences, 60-479 Poznan, Poland
Satellite cells are committed precursor cells residing in the skeletal muscle. These cells provide an almost unlimited regeneration potential to the muscle, contrary to the heart, which, although proved to contain cardiac stem cells, possesses a very limited ability for self-renewal. The idea that myoblasts (satellite cell progenies) may repopulate postinfarction scar occurred around the mid-1990s. Encouraging results of preclinical studies triggered extensive research, which led to the onset of clinical trials. These trials have shown that autologous skeletal myoblast transplantation to cure heart failure is feasible and relatively safe (observed incidences of arrhythmia). Because most of the initial studies on myoblast application into postischemic heart have been carried out as an adjunct to routine surgical procedures, the true clinical outcome of such therapy in regard to cell implantation is blurred and requires to be elucidated. The mechanism by which implantation of skeletal myoblast may improve heart function is not clear, especially in the light of inability of these cells to couple electromechanically with a host myocardium. Successful myoblast therapy depends on a number of factors, including: delivery to the target tissue, long-term survival, efficacious engraftment, differentiation into cardiomyocytes, and integration into the new, unique microenvironment. All these steps constitute a potential goal for cell manipulation aiming to improve the overall outcome of such therapy. Precise understanding of the mechanism by which cells improve cardiac function is essential in giving the sensible direction of further research.
Key words: Stem cells; Myoblast therapy; Myocardium regeneration
Address correspondence to Maciej Kurpisz, Professor, M.D., Institute of Human Genetics, Polish Academy of Sciences, Strzeszynska 32, 60-479 Poznan, Poland. Tel: +48 (61) 6579 202; Fax: +48 (61) 8233 235; E-mail: email@example.com
Overexpression of Follistatin in Human Myoblasts Increases Their Proliferation and Differentiation, and Improves the Graft Success in SCID Mice
B. F. Benabdallah, M. Bouchentouf, J. Rousseau, and J. P. Tremblay
Génétique humaine, Centre de Recherche du CHUL, Québec, Canada
Duchenne muscular dystrophy is caused by the absence of functional dystrophin, leading to the myofiber membrane instability and progressive muscle atrophy. Myoblast transplantation in dystrophic muscles is a potential therapy, as it permits the long-term restoration of dystrophin expression in transplanted muscles. However, the success of this approach is limited by the short period of muscle repair following myoblast transplantation. Myostatin, a powerful inhibitor of muscle growth, is involved in terminating the period of muscle repair following injury by reducing myoblast proliferation and differentiation. Follistatin forms a complex with myostatin, preventing its interaction with its receptor and thus blocking the myostatin signal. Here, we used a lentivirus to overexpress the follistatin protein in normal myoblasts to block the myostatin signaling. We measured the potential of transduced myoblasts to proliferate and to form multinucleated myotubes in vitro. And finally, we considered the engraftment success of those transduced myoblasts in comparison with control cells in vivo within SCID mice TA muscle. Our results first confirmed the overexpression of follistatin into lentivirus transduced myoblasts, and second showed that the overexpression of the follistatin in normal human myoblasts improved in vitro their proliferation rate by about 1.5-fold after 96 h and also their differentiation rate by about 1.6- and 1.8-fold, respectively, in the absence and in the presence of recombinant myostatin. Finally, our data demonstrated that the engraftment of human normal myoblasts overexpressing the follistatin protein into SCID mouse muscles was enhanced by twofold.
Key words: Duchenne muscular dystrophy; Myoblast transplantation; Myostatin; Follistatin
Address correspondence to Jacques P. Tremblay, Ph.D., Unité de recherche en Génétique humaine, Centre de recherche de l'Université Laval, 2705, boulevard Laurier, RC-9300, Québec, Québec, Canada G1V 4G2. Tel: (418) 654-2186; Fax: (418) 654-2207; E-mail: Jacques-P.Tremblay @crchul.ulaval.ca
Growth Factor Coinjection Improves the Migration Potential of Monkey Myogenic Precursors Without Affecting Cell Transplantation Success
Jean-François Lafreniere, Marie-Christine Caron, Daniel Skuk, Marlyne Goulet, Anissa Rahma Cheikh, and Jacques P. Tremblay
Unité de recherche en Génétique humaine, Centre Hospitalier de l'Université Laval, Ste-Foy, Québec, Canada
Duchenne muscular dystrophy (DMD) is an inherited disease and a main target of myogenic cell transplantation (MT). After the failure of the first clinical trials with DMD patients, the poor migration of transplanted cells has been suspected to be a major problem for a more effective clinical application of MT. Previous investigations suggested that the quantity and dispersion of myofibers containing donor cell nuclei might be improved by increasing the migration of the transplanted cells outside the injection sites. Because the coinjection of motogenic factors with human myoblasts enhanced their intramuscular migration following MT in SCID mice, the present study aimed to investigate whether this approach was appropriate to increase MT success in muscles of nonhuman primates. In vitro studies indicated that IGF-1 or bFGF increased components of proteolytic systems involved in myoblast migration. In vitro and in vivo experiments also demonstrated that coinjection of bFGF or IGF-1 was able to improve monkey myogenic cell migration and invasion. Sixty hours after MT in skeletal muscle tissue, the migration distances reached by monkey myoblasts increased by nearly twofold when one of the growth factors was coinjected with the cells. However, longterm observations in adult monkeys suggest that promigratory treatments are not intrinsically sufficient to improve the success of MT. Even if short-term observations reveal that grafted cells are not always trapped inside the injection site and in spite of the fact that both factors enhanced transplanted cell migration, myofibers including grafted cell nuclei were still restrained to the injection trajectory without notable difference in their amount or their dispersion. The incapacity of transplanted cells to fuse with undamaged myofibers, which are located outside the injection sites, is a priority problem to solve in order to improve transplantation success and reduce the number of injections required for the treatment of DMD patients.
Key words: Myoblast transplantation; Monkey; Migration; Growth factor; IGF-1; bFGF
Address correspondence to Jacques P. Tremblay, Unité de recherche en Génétique humaine, Centre hospitalier de l'Université Laval, 2705, boul. Laurier, RC-9300, Sainte-Foy, Québec, Canada G1V 4G2. Tel: (418) 654-2186; Fax: (418) 654-2207; E-mail: Jacques-P.Tremblay@crchul.ulaval.ca
A Biocompatible Endothelial Cell Delivery System for In Vitro Tissue Engineering
Eun Jung Lee,1 Gordana Vunjak-Novakovic,2 Yadong Wang,3 and Laura E. Niklason1
1Department of Anesthesiology, Yale University, New Haven,
2Department of Biomedical Engineering, Columbia University, New York, NY, USA
3Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
Engineering solid tissues, including cardiac muscle, requires the inclusion of a microvasculature. Prevascularization in vitro will likely be dependent upon coculturing parenchymal cells with vascular cells, on a matrix that is sufficiently porous to allow microvessel formation. In this study, we examined the behavior and function of endothelial cells on a highly porous elastomeric 3D poly(glycerol sebacate) (PGS) scaffold, to provide a flexible and biocompatible endothelial cell delivery system for developing cardiac engineered tissues with neovascularization potential. Both static and perfusion cell seeding methods were used, and the effects of surface treatment of the scaffold with various extracellular matrix components were examined. Endothelial cell adhesion and phenotype on the PGS scaffold under various flow conditions were also determined. Surface coating with laminin markedly improved the endothelial cell adhesion, survival, and proliferation. The anticoagulant phenotype of adhered endothelial cells was further regulated by the application of flow through regulation of nitric oxide expression. By providing a highly porous scaffolding that contains endothelium with anticoagulant properties, the endothelial cell-seeded PGS scaffold could provide a new basis for subsequent coculture studies with various cell types to develop complex engineered tissue constructs with vascularization capacity.
Key words: Endothelial cell function; Flow; Vascular tissue engineering; PGS scaffold
Address correspondence to Laura E. Niklason, M.D., Ph.D., Department of Anesthesiology, Yale University, 10 Amistad Street 301D, P.O. Box 208089, New Haven, CT 06520, USA. Tel: 203-737-1422; Fax: 203-785-7907; E-mail: firstname.lastname@example.org
Pig Pancreas Oxygenation at 20°C Increases Islet ATP Generation but Deteriorates Islet Function
M. Iken,1 H. Brandhorst,2 O. Korsgren,2 and D. Brandhorst2
1Department of Gastroenterology, Hepatology & Endocrinology,
Medical School, Hanover, Germany
2Department of Oncology, Radiology & Clinical Immunology, Division of Clinical Immunology, University Hospital, Uppsala, Sweden
Successful pancreas preservation during storage in oxygenated perfluorodecalin (PFD) is mainly related to oxidative ATP generation during storage. Increasing the storage temperature would accelerate this process essential for resuscitation of ischemically damaged pancreatic tissue. The present study aimed at comparing islet isolation outcome from adult pig pancreata preserved in oxygenated PFD by means of a one-layer method during storage on ice or at 20°C. Resected pancreata were intraductally flushed with cold UW solution and promptly processed (n = 6) or stored for 3 h in continuously oxygenated PFD at 4°C (n = 5) or 20°C (n = 7). Prior to digestion-filtration pancreata were intraductally injected with UW supplemented with Serva collagenase NB8 and neutral protease. Islet quality assessment determined viability, glucose stimulation index, mitochondrial activity, intracellular ATP content, and transplant function in diabetic nude mice. Pancreata oxygenated for 3 h at 20°C yielded islet numbers similar to organs oxygenated at 4°C. Compared to a storage temperature of 20°C, preservation at 4°C reduced islet ATP content (p < 0.05) as well as islet viability (p <0.05). Nevertheless, PFD storage at 20°C decreased insulin response to glucose compared to unstored pancreata (p < 0.05). In contrast to unstored pancreata or cold-stored organs, transplantation of islets isolated after oxygenation at 20°C was characterized by an early loss of transplant function in 50% of recipients (p < 0.05). The present study demonstrates that PFD storage at 20°C enhances islet ATP synthesis within a short period of oxygenation but deteriorates islet function. We conclude that the present data reflect an equilibration between reduced depression of metabolic activity resulting in damage of islets and temperature-stimulated acceleration of ATP synthesis. Future studies are required to adjust the optimum storage temperature for pancreas oxygenation in different species.
Key words: Pigs; Pancreas preservation; Preservation temperature; Islet isolation; Perfluorodecalin; ATP
Address correspondence to Daniel Brandhorst, Department of Oncology, Radiology & Clinical Immunology, University Hospital, Dag Hammarskjo ¨lds va¨g 20 (C11), 75185 Uppsala, Sweden. Tel: +46-70-4250636; Fax: +46-18-61-10222; E-mail: Daniel.Brandhorst@klinimm.uu.se
2007 Update on Allogeneic Islet Transplantation From the Collaborative Islet Transplant Registry (CITR)
The CITR Research Group
As of October 1, 2007, 25 North American medical institutions and one European islet transplant center reported detailed information to the Registry on 315 allograft recipients, of which 285 were islet alone (IA) and 30 were islet after kidney (IAK). Of the 114 IA recipients expected at 4 years after their last infusion, 12% were insulin independent, 16% were insulin dependent with detectable C-peptide, 40% had no detectable C-peptide, and 32% had missing C-peptide data or were lost to follow-up. Of the IA recipients, 72% achieved insulin independence at least once over 3 years and multiple infusions. Factors associated with achievement of insulin independence included islet size >1.0 expressed as IEQs per islet number [hazard ratio (HR) = 1.5, p = 0.06], additional infusions given (HR = 1.5, p = 0.01), lower pretransplant HbA1c (HR = 1.2 each %-age unit, p = 0.02), donor given insulin (HR = 2, p = 0.003), daclizumab given at any infusion (HR = 1.9, p = 0.06), and shorter cold storage time (HR = 1.04, p = 0.03), mutually adjusted in a multivariate model. Severe hypoglycemia prevalence was reduced from 78-83% preinfusion to less than 5% throughout the first year post-last infusion, and to 18% adjusted for missing data at 3 years post-last infusion. In Year 1 post-first infusion for IA recipients, 53% experienced a Grade 3-5 or serious adverse event (AE) and 35% experienced a severe AE related to either an infusion procedure or immunosuppression. In Year 1 post-first infusion, 33% of IA subjects and 35% of IAK subjects had an AE related to the infusion procedure, while 35% of IA subjects and only 27% of IAK subjects had an AE related to the immunosuppression therapy. Five deaths were reported, of which two were classified as probably related to the infusion procedure or immunosuppression, and 10 cases of neoplasm, of which two were classified as probably related to the procedure or immunosuppression. Islet transplantation continues to show short-term benefits of insulin independence, normal or near normal HbA1C levels, and sustained marked decrease in hypoglycemic episodes.
Key words: Islet transplantation; Type 1 diabetes; Registry; Immunosuppression
Address correspondence to Franca Benedicty Barton, M.S., The EMMES Corporation, 401 North Washington Street, Suite 700, Rockville, MD 20850, USA. Tel: (301) 251-1161, x2925; Fax: (301) 251-1355; E-mail: email@example.com
Gender-Dependent Survival of Allogeneic Trophoblast Stem Cells in Liver
Jessica Epple-Farmer,1 Bisrat G. Debeb,1 Oliver Smithies,2 and Bert Binas1
1Department of Pathobiology, College of Veterinary Medicine
and Biomedical Sciences, Texas A&M University, College Station, TX,
2Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, USA
In view of the well-known phenomenon of trophoblast immune privilege, trophoblast stem cells (TSCs) might be expected to be immune privileged, which could be of interest for cell or gene therapies. Yet in the ectopic sites tested so far, TSC transplants fail to show noticeable immune privilege and seem to lack physiological support. However, we show here that after portal venous injection, green fluorescent protein (GFP)-labeled TSCs survive for several months in the livers of allogeneic female but not male mice. Gonadectomy experiments revealed that this survival does not require the presence of ovarian hormones but does require the absence of testicular factors. By contrast, GFP-labeled allogeneic embryonic stem cells (ESCs) are reliably rejected; however, these same ESCs survive when mixed with unlabeled TSCs. The protective effect does not require immunological compatibility between ESCs and TSCs. Tumors were not observed in animals with either successfully engrafted TSCs or coinjected ESCs. We conclude that in a suitable hormonal context and location, ectopic TSCs can exhibit and confer immune privilege. These findings suggest applications in cell and gene therapy as well as a new model for studying trophoblast immunology and physiology.
Key words: Trophoblast; Stem cells; Cell therapy; Transplantation; Immune privilege; Mice
Address correspondence to Bert Binas at his current address: Division of Molecular & Life Sciences, College of Science and Technology, Hanyang University, 1271 Sa 1-dong, Sangrok-gu, Ansan-si, Gyeonggi-do, Korea, 426-791. Tel: +82-31-400-5517; E-mail: firstname.lastname@example.org
Liver Cell Transplantation: Basic Investigations for Safe Application in Infants and Small Children
Jochen Meyburg,1 Krassimira Alexandrova,2 Marc Barthold,2 Sabine Kafert-Kasting,2 Andrea S. Schneider,3 Masoumeh Attaran,3 Friederike Hoerster,1 Jan Schmidt,4 Georg F. Hoffmann,1 and Michael Ott3
1Department of General Pediatrics, University Children's
Hospital, 69120 Heidelberg, Germany
2Cytonet GmbH & Co. KG, 30625 Hannover, Germany
3Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, 30623 Hannover, Germany
4Department of General and Visceral and Transplantation Surgery, University Hospital, 69120 Heidelberg, Germany
Liver cell transplantation (LCT) is a very promising method for the use in pediatric patients. It is significantly less invasive than whole organ transplantation, but has the potential to cure or at least to substantially improve severe disorders like inborn errors of metabolism or acute liver failure. Prior to a widespread use of the technique in children, some important issues regarding safety and efficacy must be addressed. We developed a mathematical model to estimate total hepatocyte counts in relation to bodyweight to make possible more appropriate dose calculations. Different liver cell suspensions were studied at different flow rates and different catheter sizes to determine mechanical damage of cells by shear forces. At moderate flow rates, no significant loss of viability was observed even at a catheter diameter of 4.2F. Addition of heparin to the cell suspension is favored, which is in contrast to previous animal experiments. Mitochondrial function of the hepatocytes was determined with the WST-1 assay and was not substantially altered by cryopreservation. We conclude that especially with the use of small catheters, human LCT should be safe and efficient even in small infants and neonates.
Key words: Hepatocyte transplantation; Cell application; Cryopreservation; Portal vein catheter; Children
Address correspondence to Jochen Meyburg, University Children's Hospital, Im Neuenheimer Feld 150, D-69120 Heidelberg, Germany. Tel: +49 6221 5638428; Fax: +49 6221 565626; E-mail: email@example.com
Primate Adult Brain Cell Autotransplantation, a Pilot Study in Asymptomatic MPTP-Treated Monkeys
Jean-François Brunet,1 D. Eugene Redmond, Jr.,2 and Jocelyne Bloch1
1Department of Neurosurgery, Lausanne University Hospital,
1011 Lausanne, Switzerland
2Department of Psychiatry and Neurosurgery, Yale University School of Medicine, New Haven, CT, USA
Autologous brain cell transplantation might be useful for repairing lesions and restoring function of the central nervous system. We have demonstrated that adult monkey brain cells, obtained from cortical biopsy and kept in culture for a few weeks, exhibit neural progenitor characteristics that make them useful for brain repair. Following MPTP treatment, primates were dopamine depleted but asymptomatic. Autologous cultured cells were reimplanted into the right caudate nucleus of the donor monkey. Four months after reimplantation, histological analysis by stereology and TH immunolabeling showed that the reimplanted cells successfully survived, bilaterally migrated in the whole striatum, and seemed to have a neuroprotection effect over time. These results may add a new strategy to the field of brain neuroprotection or regeneration and could possibly lead to future clinical applications.
Key words: Adult brain cells; Autograft; MPTP-treated monkeys
Address correspondence to Jean-Franc¸ois Brunet, Neurosurgery Research Group, Department of Neurosurgery, CHUV-Beaumont-Pav 3, Bugnon 46-CH-1011, Lausanne, Switzerland. Tel: (41 21) 314 21 20; Fax: (41 21) 314 08 24; E-mail: Jean-Francois.Brunet@chuv.ch
Reversal of Dopaminergic Degeneration in a Parkinsonian Rat Following Micrografting of Human Bone Marrow-Derived Neural Progenitors
Aleksandra Glavaski-Joksimovic,1* Tamas Virag,1*# Qin A. Chang,1§ Neva C. West,1 Thomas A. Mangatu,1 Michael P. McGrogan,2 Millicent Dugich-Djordjevic,2** and Martha C. Bohn1
1Department of Pediatrics, Neurobiology Program, Children's
Memorial Research Center, Feinberg School of Medicine, Northwestern University,
Chicago, IL, USA
2SanBio Inc., Mountain View, CA, USA
Parkinson's disease (PD) is a common neurodegenerative disease characterized
by the selective loss of dopaminergic (DA) neurons in the midbrain. Various
types of stem cells that have potential to differentiate into DA neurons
are being investigated as cellular therapies for PD. Stem cells also secrete
growth factors and therefore also may have therapeutic effects in promoting
the health of diseased DA neurons in the PD brain. To address this possibility
in an experimental model of PD, bone marrow-derived neuroprogenitor-like
cells were generated from bone marrow procured from healthy human adult
volunteers and their potential to elicit recovery of damaged DA axons was
studied in a partial lesion rat model of PD. Following collection of bone
marrow, mesenchymal stem cells (MSC) were isolated and then genetically
modified to create SB623 cells by transient transfection with the intracellular
domain of the Notch1 gene (NICD), a modification that upregulates expression
of certain neuroprogenitor markers. Ten deposits of 0.5 ml
of SB623 cell suspension adjusted from 6,000 to 21,000 cells/ml
in PBS or PBS alone were stereotaxically placed in the striatum 1 week
after the nigrostriatal projection had been partially lesioned in adult
F344 rats by injection of 6-hydroxydopamine (6-OHDA) into the striatum.
At 3 weeks, a small number of grafted SB623 cells survived in the lesioned
striatum as visualized by expression of the human specific nuclear matrix
protein (hNuMA). In rats that received SB623 cells, but not in control
rats, dense tyrosine hydroxylase immunoreactive (TH-ir) fibers were observed
around the grafts. These fibers appeared to be rejuvenated host DA axons
because no TH-ir in soma of surviving SB623 cells or coexpression of TH
and hNuMA-ir were observed. In addition, dense serotonin immunoreactive
(5-HT-ir) fibers were observed around grafted SB623 cells and these fibers
also appeared to be of the host origin. Also, in some SB623 grafted rats
that were sacrificed within 2 h of dl-amphetamine injection, hot
spots of c-Fos-positive nuclei that coincided with rejuvenated dense TH
fibers around the grafted SB623 cells were observed, suggesting increased
availability of DA in these locations. Our observations suggest that NICD-transfected
MSC hold potential as a readily available autologous or allogenic cellular
therapy for ameliorating the degeneration of DA and 5-HT neurons in PD
Key words: Parkinson's disease; Human mesenchymal stem cells; Nigrostriatal system; 6-OHDA; Neuroprotection; Notch1; Dopamine; c-Fos
Address correspondence to Martha C. Bohn, Ph.D., Medical Research Institute Council Professor, Director, Neurobiology Program, Children's Memorial Research Center (CMRC), Feinberg School of Medicine, Northwestern University, 2300 Children's Plaza, Box 209, Chicago, IL 60614, USA. Tel: (773) 755-6355; Fax: (773) 755-6344; E-mail: firstname.lastname@example.org
#Present address: NIH, NHLBI, 10 Center Dr., Bethesda, MD 20892, USA.
§Present address: Department of Neurosurgery, Feinberg School of Medicine, Northwestern University, 676 N. St. Clair St., Chicago, IL 60611, USA.
**Present address: Neurocore, San Diego, CA, USA.
Functional Engraftment of the Medial Ganglionic Eminence Cells in Experimental Stroke Model
Marcel M. Daadi,1 Sang Hyung Lee,1 Ahmet Arac,1 Brad A. Grueter,2 Rishi Bhatnagar,1 Anne-Lise Maag,1 Bruce Schaar,1 Robert C. Malenka,2 Theo D. Palmer,1 and Gary K. Steinberg1
1Department of Neurosurgery and Stanford Stroke Center, Stanford
University School of Medicine, Stanford, CA, USA
2Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA
Currently there are no effective treatments targeting residual anatomical and behavioral deficits resulting from stroke. Evidence suggests that cell transplantation therapy may enhance functional recovery after stroke through multiple mechanisms. We used a syngeneic model of neural transplantation to explore graft-host communications that enhance cellular engraftment.The medial ganglionic eminence (MGE) cells were derived from 15-day-old transgenic rat embryos carrying green fluorescent protein (GFP), a marker, to easily track the transplanted cells. Adult rats were subjected to transient intraluminal occlusion of the medial cerebral artery. Two weeks after stroke, the grafts were deposited into four sites, along the rostro-caudal axis and medially to the stroke in the penumbra zone. Control groups included vehicle and fibroblast transplants. Animals were subjected to motor behavioral tests at 4 week posttransplant survival time. Morphological analysis demonstrated that the grafted MGE cells differentiated into multiple neuronal subtypes, established synaptic contact with host cells, increased the expression of synaptic markers, and enhanced axonal reorganization in the injured area. Initial patch-clamp recording demonstrated that the MGE cells received postsynaptic currents from host cells. Behavioral analysis showed reduced motor deficits in the rotarod and elevated body swing tests. These findings suggest that graft-host interactions influence the fate of grafted neural precursors and that functional recovery could be mediated by neurotrophic support, new synaptic circuit elaboration, and enhancement of the stroke-induced neuroplasticity.
Key words: Cell transplantation; Graft-host interactions; Stroke-injured environment; Synaptogenesis; Axonal sprouting; Neuroplasticity
Address correspondence to Marcel Daadi, Ph.D., Department of Neurosurgery, Stanford University, MSLS P304, 1201 Welch Rd., Stanford, CA 94305-5487, USA. Tel: (650) 724-9998; Fax: (650) 498-4134; E-mail: email@example.com