中国生物工程杂志

Parkinson's disease (PD) is a common neurodegenerative disorder with no effective protective treatment, characterized by a massive degeneration of dopaminergic neurons in the substantia nigra (SNpc) and the subsequent loss of their projecting nerve fibers in the striatum. The major neurochemical manifestation of this disorder is the loss of the neurotransmitter dopamine (DA) in the striatum as a result of the progressive degeneration of the dopaminergic neurons in the substantia nigra. There have been significant progresses in recent years reporting on the use of mesenchymal stem cells（MSCs）in gene therapy, with specific application towards PD. MSCs, a kind of multipotent adult progenitor cells, are considered as a useful vehicle for cell and gene therapy because of their multiple differentiation potentiality and self-transplantation. The present study was focused on treating rat model of PD using human tyrosine hydroxylase gene (hTH) 、human aromatic L-amino acid decarboxylase gene (hAADC) and human GTP cyclohydrolase I gene (hGCH-I) engineered MSCs, in order to provide a better understanding about the application of these cells in the therapeutic benifit of PD. The gene of hTH、hAADC and hGCH-I were introduced via recombinant adeno-associated virus (rAAV) infection into the MSCs in vitro. The genetically modified MSCs expressing hTH, hAADC and hGCH-I were transplanted into the striatum of PD rat models. The behavior, the nigra-striatal level of DA and its metabolite were detected. The results of present study were shown as follows：hTH, hAADC, hGCH-I and LacZ gene were transfected into MSCs with adeno-associated virus vectors. The HEK293 packaging cells (ATCC) were transfected with the plasmids of pAAV-hTH, pAAV-hAADC, pAAV-hGCH-I, pAAV-LacZ, pAAV-RC, pHelper by using calcium phosphate precipitation. Titer was detected using HT1080 cells. Viral particles were collected and used to infect MSCs. The purified modified MSCs expressing the three kinds of genes were selected separately and were grafted in the striatum of the PD model rats in the lesion side. The MSCs genetically modified suvived well 12 weeks after transplantation. The improvements of the behavior were observed every week after transplantation. Compared with the control group, the rounds of asymmetric rotation after apomorphine administration decreased in the groups double or triple genes engineered MSCs grafted（p<0.01）; During the last 4 weeks, the behavioral recovery of triple gene tra