Triarhou L C, Solà C, Mengod G, García-Ladona F J, Landwehrmeyer B, Ghetti B, Palacios J M
Department of Pathology, Indiana University School of Medicine, Indianapolis 46202, USA.
Cell Transplant. 1995 Jan-Feb;4(1):39-48. doi: 10.1177/096368979500400107.
Mesencephalic cell suspensions were prepared from E12 wild-type (+/+) mouse embryos and stereotaxically implanted into the dorsal neostriatum of weaver mutant mice (wv/wv), which have a genetic mesostriatal dopamine (DA) deficiency. Survival of DA neurons in the grafts was documented by tyrosine hydroxylase (TH) immunocytochemistry. Axon growth was monitored by immunocytochemistry using a battery of antibody markers, and the cellular localization of structural protein and receptor RNA transcripts was studied by in situ hybridization histochemistry using [32P]oligonucleotide probes. The cell suspension grafts exhibited strong immunoreactivity for neural cell adhesion molecule (N-CAM), growth-associated phosphoprotein GAP-43, microtubule-associated protein 2 (MAP2), beta-amyloid protein precursor (beta APP), and phosphorylated neurofilament epitopes (clone SMI-31); intermediate-to-high levels of immunoreactivity were seen for synaptophysin. High levels of hybridization were found in the grafts for the RNA transcripts of GAP-43, MAP2, and isoforms beta APP695, beta APP714 and beta APP751 of the beta APP. No hybridization signal was detected in the grafts for DA D2 or neurotensin receptor mRNAs, both of which are normally expressed by nigral DA neurons. DA receptor autoradiography using the D2/D3 agonist [3H]CV 205-502 as a ligand showed no binding in the transplants, indicating an apparent abnormality of grafted cells; neurotensin binding sites, labeled with [125I]neurotensin, were visualized in the suspensions, indicating the possibility that receptors could be present but that RNA message levels might be too low to allow detection. These findings offer a molecular correlate of axonal, dendritic and structural protein expression by transplanted mesencephalic neurons; further, they suggest that specific functional properties of grafted nigral cells are maintained after transplantation, while other aspects of their cellular biology may be compromised.
中脑细胞悬液取自E12野生型（+/+）小鼠胚胎，并通过立体定位植入织工突变小鼠（wv/wv）的背侧新纹状体，这些小鼠存在遗传性中脑纹状体多巴胺（DA）缺乏。通过酪氨酸羟化酶（TH）免疫细胞化学记录移植中DA神经元的存活情况。使用一系列抗体标记物通过免疫细胞化学监测轴突生长，并使用[32P]寡核苷酸探针通过原位杂交组织化学研究结构蛋白和受体RNA转录本的细胞定位。细胞悬液移植对神经细胞粘附分子（N-CAM）、生长相关磷蛋白GAP-43、微管相关蛋白2（MAP2）、β-淀粉样蛋白前体（βAPP）和磷酸化神经丝表位（克隆SMI-31）表现出强烈的免疫反应性；突触素的免疫反应性为中度至高度。在移植中发现GAP-43、MAP2以及βAPP的βAPP695、βAPP714和βAPP751同工型的RNA转录本有高水平杂交。在移植中未检测到DA D2或神经降压素受体mRNA的杂交信号，这两种受体通常由黑质DA神经元表达。使用D2/D3激动剂[3H]CV 205-502作为配体的DA受体放射自显影显示移植中无结合，表明移植细胞存在明显异常；用[125I]神经降压素标记的神经降压素结合位点在悬液中可见，这表明受体可能存在，但RNA信息水平可能过低而无法检测到。这些发现为移植的中脑神经元的轴突、树突和结构蛋白表达提供了分子关联；此外，它们表明移植后黑质细胞的特定功能特性得以维持，而其细胞生物学的其他方面可能受到损害。
