15-07-08(21:51:46)
Authors:
Capetian P 1,2
Krause M 2
Papazoglou A 2
Ditter M 1
Nikkhah G 2
Institutions:
1 Department of Neuropahtology, University clinic Freiburg
2 Department of Stereotactic Neurosurgery, University clinic Freiburg
Title of abstract : Inducible conditional ablation of transgenic intracerebral fetal tissue grafts
Abstract text:
Intracerebral grafting of fetal tissue is a well established model and able to ameliorate symptoms in many animal models of brain pathologies. Yet there exists little knowledge about the role different cellular subcomponents of the grafts play in functional improvement. This knowledge could, however, lead to a better understanding of neurotransplantation and improve fetal tissue grafting procedures. Information about the function of certain cellsof the graft can be obtained by their selective ablation.
Here we present preliminary results demonstrating the feasibility of selectively ablating transgenic intracerebral fetal grafts: The inducible diphtheria toxin receptor mouse model (iDTR) (Buch et al., 2005) renders cells sensitive to diphtheria toxin (DTx) by cre-mediated excision of a STOP-cassette.
In this experiment, male iDTR mice were mated with mice ubiquitiously expressing the CRE-recombinase under the CMV-promoter (CREdel), resulting in embryos expressing the human DTR on every body cell. Ventral mesencephalic single cell suspension grafts of the derived embryos (E14) were transplanted into the right striatum of healthy rats (n = 4). After three weeks of engraftment the rats were injected intraperitoneally with 5 or 10 ng/g body weight of DTx twice daily for 7 days in order to ablate the engrafted cells. After 1 week and 7 weeks, resp., the rats were perfused and serial immunofluorescent stainings of vibratomized brain sections against NeuN, TH, M2/M6, GFAP and DTR were performed.
In the high dose group there was nearly complete graft ablation after seven weeks, only few cell bodies positive for the human DTR could still be detected. Incomplete or nearly absent graft ablation was observed in the low dose group. The surrounding host tissue remained unaffected in all cases.
These results demonstrate that the iDTR model can be used for invivo graft ablation and encourage further experiments checking for the selective ablation of distinct cellular subtypes of the graft, by usage of other cell-specific CRE-models.
