Third trimester human amniotic fluid cells from caesarean births; a new tool for therapy in neurodegenerative disorders

Recent evidences indicate that stem cells could be a good tool to reduce the secondary degeneration in spinal cord injury (1). During gestation several different cells, arising from all three germ layers, are released into the amniotic fluid (AF), and might be a novel, large and accessible reservoir of stem cells (2, 3). The endeavour of this work was to use cells isolated from caesarean births third trimester AF (see Abstract Bottai et al. SINS 2009) as a therapeutic tool in a mouse model of spinal cord injury (SCI). Three cell cultures, selected on the basis of the immunocytochemical and cytofluorimetric phenotype, were used for transplantation in a mouse model of contusive SCI. All these cultures expressed mesenchymal markers, but while #3.5 and # 3.6 were directed to the muscle-neural lineage (#3.6 also expressed CD117), #1.1 was directed to the perivascular lineage. All the transplanted cells, injected intravenously one week after the lesion, were labelled using Quantum dot (Invitrogen) and immunosoppression was applied starting one day before transplantation. We evaluated the hindlimb motor recovery over a period of 35 days following the lesion by mean of the Basso Mouse Scale (4). Starting from 14 days after transplantation, cell cultures #3.6 and #3.5 induced an increased recovery of motor functions than PBS-treated control, whereas cell culture #1.1 failed. One month after i.v. transplantation several Qdot positive cells were found at the site of injury and some of these Qdot labelled cells were also positives for β-tubulin III and GFAP immunostaining. Transplanted cells were detected at the lesion site and up to 4 mm rostrally to the injured area. In a complementary set of experiments we transplanted AF cells into a spinal cord which was subjected to hemisection at T8 level. Animals were divided into three groups: 1) lesioned mice injected with PBS, 2) lesioned mice treated with intraspinal administration of AF cells (#3.6 culture) embedded in hydrogel and 3) lesioned mice treated with intraspinal administration of hydrogel alone. From one week after injury AF cells-hydrogel treated mice showed a better motor recovery compared to hydrogel and PBS treated mice, and the difference was very significant after 28 days. Confocal analysis of transversal sections revealed the presence of Qdot positive cells surrounding the lesion site, indicating that AF cells migrated out of the hydrogel and survived over one month after transplantation. These data imply that the administration of amniotic fluid derived cells with a muscle-neural phenotype can attenuate secondary degeneration following traumatic lesion to the spinal cord by dropping the cellular component of neuroinflammatory reaction. References: 1. Schultz SS (2005) Curr Drug Targets 6(1): 63-73 2. Gosden CM (1983) British Medical Bullettin 39(4): 348-354 3. Prusa AR et al. (2004) Am J Obstet Gynecol 191(1): 309-314 4. Basso DM et al. (2006) J Neurotrauma 23(5): 635-5