title: Umbilical cord blood mesenchymal stromal cells are neuroprotective and promote  regeneration in a rat optic tract model.
abstract: Exploitation of the ability of stem cells to protect damaged neuronal tissue may be a more viable strategy than cell replacement for repair of the central nervous system (CNS). In this study we assessed the capacity of human umbilical cord blood (hUCB)-derived mesenchymal stromal cells (MSCs) to protect and promote regeneration of axotomised neurons within the rat optic system. The optic tract of neonatal rats was transected at the level of the lateral geniculate nucleus, and MSCs were introduced into the lesion site. MSCs survived well up to 2 weeks after grafting, and did not migrate significantly or differentiate. In the presence of MSC grafts, host axonal processes were found to be present in the lesion site, and there was stimulation of an endogenous neural precursor population. Four weeks after grafting, retrograde tracer experiments demonstrated that grafted MSCs, as well as cells of a human fibroblast line, exerted a neuroprotective effect, rescuing a significant percentage of axotomised retinal ganglion cells (RGCs). Further experiments with retrograde and anterograde tracers strongly indicated that MSCs could also promote re-growth of axotomised RGCs to their target, the superior colliculus (SC). Further analysis showed that hUCB-derived MSCs secreted several immunomodulatory and neurotrophic factors in vitro, including TGFbeta1, CNTF, NT-3 and BDNF, which are likely to play a role in neuroprotection. Our data indicate that hUCB-derived MSCs may be an easily accessible, widely available source of cells that can contribute towards neural repair through rescue and regeneration of injured neurons.
authors.affiliation: Department of Cellular and Molecular Neuroscience, Imperial College London, UK.
authors.forename: Isabel
authors.initials: I
authors.lastname: Zwart
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Hill
authors.forename: Faisal
authors.initials: F
authors.lastname: Al-Allaf
authors.forename: Mili
authors.initials: M
authors.lastname: Shah
authors.forename: John
authors.initials: J
authors.lastname: Girdlestone
authors.forename: Athirah B R
authors.initials: AB
authors.lastname: Sanusi
authors.forename: Huseyin
authors.initials: H
authors.lastname: Mehmet
authors.forename: Roberto
authors.initials: R
authors.lastname: Navarrete
authors.forename: Cristina
authors.initials: C
authors.lastname: Navarrete
authors.forename: Ling-Sun
authors.initials: LS
authors.lastname: Jen