ABSTRACT
OBJECTIVE: Mesenchymal stem/stromal cells (MSC) promote recovery after spinal cord injury (SCI) using adult bone marrow MSC (BM-MSC). Newborn tissues are a convenient source of MSC that does not involve an invasive procedure for cell collection. In this study the authors tested the effects of rat amnion MSC clone (rAM-MSC) in SCI. METHODS: We tested intra-parenchymal injection of a GFP+ rat rAM-MSC clone derived from E18.5 rats in rat SCI and measured behavioral recovery (BBB scores), histology and X-ray opacity. Expression of aggrecan was measured in culture after treatment with TGFß. RESULTS: Injection of rAM-MSC after SCI did not improve BBB scores compared to control vehicle injections; rather they reduced scores significantly over 6 weeks. Spinal cords injected with rAM-MSC were hard in regions surrounding the SCI site, which was confirmed by X-ray opacity. Whole mount imaging of these cords showed minimal tissue loss in the SCI site that occurred in SCI controls, and persistence of GFP+ rAM-MSC. Mason's Trichrome staining of tissue sections showed more intense staining for extracellular matrix (ECM) surrounding and extending beyond the SCI site with injections of rAM-MSC but not in controls. In response to TGF-ß treatment in culture, chondrogenic aggrecan was expressed at higher levels in rAM-MSC than in rBM-MSC, suggesting that the upregulation of TGF-ß in SCI sites may promote chondrogenic differentiation. CONCLUSION: Acute injection after SCI of a clonally expanded rAM-MSC resulted in aberrant differentiation towards a chondrocytic phenotype that disrupts the spinal cord and inhibits behavioral recovery after SCI. It will be critical to ensure that injection of extensively expanded neonatal cells do not differentiate aberrantly in traumatic CNS tissue and disrupt recovery.
Subject(s)
Amnion/cytology , Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells/cytology , Spinal Cord Injuries/therapy , Animals , Cell Differentiation/physiology , Cells, Cultured , Disease Models, Animal , Female , Mesenchymal Stem Cell Transplantation/methods , Mesenchymal Stem Cells/physiology , Rats, Sprague-Dawley , Spinal Cord/pathology , Spinal Cord/physiopathology , Spinal Cord Injuries/pathologyABSTRACT
By virtue of expressions of glial and neural surface markers and capability of neurotransmitter metabolism, amniotic epithelial cells are considered as candidate cell type for transplantation strategies to treat neurological disorders. Previously, we have reported neurotrophism exhibited by human amniotic epithelial cells when transplanted after spinal cord injury in bonnet monkeys. Amniotic epithelial cells were believed to secrete an "Epidermal Growth Factor (EGF)-like" factor and exact identification was not made. At this juncture, through the present study it was found that, chicken neural retinal cells when grown alone failed to survive and contrarily when either co-cultured with chicken amniotic epithelial cells/cultured in amniotic epithelial cell conditioned medium not only survived but also showed extensive differentiation. Fibroblast Growth Factor-2 (FGF-2) plays a critical role in retinal development especially in chicken neural retinal development. However, immunoassay using western blot did not revealed the presence of any already known isoforms of FGF-2 in the medium. It is interesting to note that while factor secreted by amniotic epithelial cells resembles EGF and/or FGF-2 in its biological action, known isoforms of them were not detected. Considering the biological closeness between EGF and FGF-2, results indicate the possibility of a novel isoform of these growth factors secreted by amniotic epithelial cells. Further studies will establish the nature of this novel factor which will enhance the application of this interesting cell type for neural transplantations.
Subject(s)
Amnion/cytology , Epithelial Cells/metabolism , Nerve Growth Factors/metabolism , Animals , Blotting, Western , Cell Differentiation , Cell Survival , Cells, Cultured , Chickens , Epidermal Growth Factor/genetics , Epidermal Growth Factor/metabolism , Eye/cytology , Fibroblast Growth Factor 2/genetics , Fibroblast Growth Factor 2/metabolism , Gene Expression Regulation , Humans , RNA, Messenger/genetics , RNA, Messenger/metabolismABSTRACT
By virtue of expressions of glial and neural surface markers and capability of neurotransmitter metabolism, amniotic epithelial cells are considered as candidate cell type for transplantation strategies to treat neurological disorders. Previously, we have reported neurotrophism exhibited by human amniotic epithelial cells when transplanted after spinal cord injury in bonnet monkeys. Amniotic epithelial cells were believed to secrete an "Epidermal Growth Factor (EGF)-like" factor and exact identification was not made. At this juncture, through the present study it was found that, chicken neural retinal cells when grown alone failed to survive and contrarily when either co-cultured with chicken amniotic epithelial cells/cultured in amniotic epithelial cell conditioned medium not only survived but also showed extensive differentiation. Fibroblast Growth Factor-2 (FGF-2) plays a critical role in retinal development especially in chicken neural retinal development. However, immunoassay using western blot did not revealed the presence of any already known isoforms of FGF-2 in the medium. It is interesting to note that while factor secreted by amniotic epithelial cells resembles EGF and/or FGF-2 in its biological action, known isoforms of them were not detected. Considering the biological closeness between EGF and FGF-2, results indicate the possibility of a novel isoform of these growth factors secreted by amniotic epithelial cells. Further studies will establish the nature of this novel factor which will enhance the application of this interesting cell type for neural transplantations.
Subject(s)
Humans , Animals , Amnion/cytology , Epithelial Cells , Fibroblast Growth Factor 2 , Epidermal Growth Factor/genetics , Epidermal Growth Factor/metabolism , Nerve Growth Factors , RNA, Messenger/genetics , RNA, Messenger/metabolism , Blotting, Western , Cell Differentiation , Cell Survival , ChickensABSTRACT
By virtue of expressions of glial and neural surface markers and capability of neurotransmitter metabolism, amniotic epithelial cells are considered as candidate cell type for transplantation strategies to treat neurological disorders. Previously, we have reported neurotrophism exhibited by human amniotic epithelial cells when transplanted after spinal cord injury in bonnet monkeys. Amniotic epithelial cells were believed to secrete an "Epidermal Growth Factor (EGF)-like" factor and exact identification was not made. At this juncture, through the present study it was found that, chicken neural retinal cells when grown alone failed to survive and contrarily when either co-cultured with chicken amniotic epithelial cells/cultured in amniotic epithelial cell conditioned medium not only survived but also showed extensive differentiation. Fibroblast Growth Factor-2 (FGF-2) plays a critical role in retinal development especially in chicken neural retinal development. However, immunoassay using western blot did not revealed the presence of any already known isoforms of FGF-2 in the medium. It is interesting to note that while factor secreted by amniotic epithelial cells resembles EGF and/or FGF-2 in its biological action, known isoforms of them were not detected. Considering the biological closeness between EGF and FGF-2, results indicate the possibility of a novel isoform of these growth factors secreted by amniotic epithelial cells. Further studies will establish the nature of this novel factor which will enhance the application of this interesting cell type for neural transplantations.(AU)
