title: Delayed post-treatment with bone marrow-derived mesenchymal stem cells is neurorestorative of striatal medium-spiny projection neurons and improves motor function after neonatal rat hypoxia-ischemia.
abstract: Perinatal hypoxia-ischemia is a major cause of striatal injury and may lead to cerebral palsy. This study investigated whether delayed administration of bone marrow-derived mesenchymal stem cells (MSCs), at one week after neonatal rat hypoxia-ischemia, was neurorestorative of striatal medium-spiny projection neurons and improved motor function. The effect of a subcutaneous injection of a high-dose, or a low-dose, of MSCs was investigated in stereological studies. Postnatal day (PN) 7 pups were subjected to hypoxia-ischemia. At PN14, pups received treatment with either MSCs or diluent. A subset of high-dose pups, and their diluent control pups, were also injected intraperitoneally with bromodeoxyuridine (BrdU), every 24h, on PN15, PN16 and PN17. This permitted tracking of the migration and survival of neuroblasts originating from the subventricular zone into the adjacent injured striatum. Pups were euthanized on PN21 and the absolute number of striatal medium-spiny projection neurons was measured after immunostaining for DARPP-32 (dopamine- and cAMP-regulated phosphoprotein-32), double immunostaining for BrdU and DARPP-32, and after cresyl violet staining alone. The absolute number of striatal immunostained calretinin interneurons was also measured. There was a statistically significant increase in the absolute number of DARPP-32-positive, BrdU/DARPP-32-positive, and cresyl violet-stained striatal medium-spiny projection neurons, and fewer striatal calretinin interneurons, in the high-dose mesenchymal stem cell (MSC) group compared to their diluent counterparts. A high-dose of MSCs restored the absolute number of these neurons to normal uninjured levels, when compared with previous stereological data on the absolute number of cresyl violet-stained striatal medium-spiny projection neurons in the normal uninjured brain. For the low-dose experiment, in which cresyl violet-stained striatal medium-spiny neurons alone were measured, there was a lower statistically significant increase in their absolute number in the MSC group compared to their diluent controls. Investigation of behavior in another cohort of animals showed that delayed administration of a high-dose of bone marrow-derived MSCs, at one week after neonatal rat hypoxia-ischemia, improved motor function on the cylinder test. Thus, delayed therapy with a high- or low-dose of adult MSCs, at one week after injury, is effective in restoring the loss of striatal medium-spiny projection neurons after neonatal rat hypoxia-ischemia and a high-dose of MSCs improved motor function.
authors.affiliation: Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand.
authors.forename: Stella H
authors.initials: SH
authors.lastname: Cameron
authors.affiliation: Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand.
authors.forename: Amr J
authors.initials: AJ
authors.lastname: Alwakeel
authors.affiliation: Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand.
authors.forename: Liping
authors.initials: L
authors.lastname: Goddard
authors.affiliation: Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand.
authors.forename: Catherine E
authors.initials: CE
authors.lastname: Hobbs
authors.affiliation: Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand.
authors.forename: Emma K
authors.initials: EK
authors.lastname: Gowing
authors.affiliation: Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand.
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Barnett
authors.affiliation: Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Kohe
authors.affiliation: Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand.
authors.forename: Rachel J
authors.initials: RJ
authors.lastname: Sizemore
authors.affiliation: Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand. Electronic address: dorothy.oorschot@anatomy.otago.ac.nz.
authors.forename: Dorothy E
authors.initials: DE
authors.lastname: Oorschot
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D015703:Antigens, CD / Q000378:metabolism; D001835:Body Weight; D064032:Calbindin 2 / Q000378:metabolism; D064987:Cell- and Tissue-Based Therapy / Q000379:methods*; D003342:Corpus Striatum / Q000473:pathology*; D004195:Disease Models, Animal; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32 / Q000378:metabolism; D020925:Hypoxia-Ischemia, Brain / Q000150:complications / Q000473:pathology / Q000628:therapy; D020547:Lateral Ventricles / Q000166:cytology; D008297:Male; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D019957:Motor Skills Disorders / Q000209:etiology / Q000628:therapy*; D055495:Neurogenesis; D009474:Neurons / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D015703:Antigens, CD; D064032:Calbindin 2; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32
keywords: Adult mesenchymal stem cells; Cavalieri's method; DARPP-positive striatal neurons; Dose-effect; Forepaw motor skills; Stereology; Striatal medium-spiny projection neurons; Striatal neurorestoration; Subcutaneous injection