Lustig R H, Hua P, Smith L S, Wang C, Chang C
Department of Pediatrics, University of Wisconsin, Madison 53792.
Mol Cell Neurosci. 1994 Dec;5(6):587-96. doi: 10.1006/mcne.1994.1072.
Androgen alters neurite outgrowth, synaptic organization, and cell survival in various portions of the brain and spinal cord. However, examination of the specific effects of androgen on neurons in vivo has been difficult. Previously, an in vitro model for the effects of estrogen on neurons was developed and characterized, using an estrogen receptor (ER)-transfected PC12 rat pheochromocytoma cell line. This model demonstrated estrogenic regulation of neurite outgrowth, spine formation, and gap junction formation. Similarly, an in vitro model for the effects of androgen on neurons is now described. Wild-type cells (PC12-WT) were stably transfected with an expression vector coding for the full-length cDNA for the human androgen receptor (AR). Resultant clones were isolated, screened for incorporation of vector and expression of AR mRNA and protein, and analyzed for morphologic responses to androgen. PC12-WT, NE09 (ER-negative, AR-negative), SER8 (ER-positive, AR-negative), and AR8 (ER-negative, AR-positive) cells were exposed to 10 ng/ml nerve growth factor (NGF), along with 0-10(-7) M dihydrotestosterone (DHT) for 2 days. AR8 cells demonstrated an androgen dose-dependent increase in mean neurite length, branch order, and neurite field area, whereas neurite branch segment length and soma area were not affected by androgen. PC12-WT, NE09, and SER8 cells exhibited no alterations in cell morphology with DHT exposure. Because of the synergistic effects of DHT and NGF, the regulation of NGF receptor mRNA by DHT was evaluated; however, no significant induction of either trkA or p75 mRNA expression by androgen was documented. The results suggest that in AR-positive PC12 cells, androgen acts additively with NGF to increase neurite outgrowth; but androgen effects are mediated specifically through branching and arborization. These responses are similar to developmental studies of androgen effects in vivo. Thus, androgen appears to induce an inherent neural morphologic program in AR-containing cells, which increases the receptive field of these cells, increasing the likelihood for interneural communication, although not promoting communication itself. These cell lines will provide a unique in vitro system for studying mechanisms of androgen-neuron interactions.
雄激素会改变大脑和脊髓各部位的神经突生长、突触组织及细胞存活。然而，在体内研究雄激素对神经元的具体作用颇具难度。此前，利用雌激素受体（ER）转染的PC12大鼠嗜铬细胞瘤细胞系，构建并表征了雌激素对神经元作用的体外模型。该模型证明了雌激素对神经突生长、棘突形成和缝隙连接形成的调节作用。同样，现在描述了一种雄激素对神经元作用的体外模型。用编码人雄激素受体（AR）全长cDNA的表达载体稳定转染野生型细胞（PC12-WT）。分离得到所得克隆，筛选载体整合情况及AR mRNA和蛋白的表达，并分析其对雄激素的形态学反应。将PC12-WT、NE09（ER阴性、AR阴性）、SER8（ER阳性、AR阴性）和AR8（ER阴性、AR阳性）细胞暴露于10 ng/ml神经生长因子（NGF）以及0 - 10⁻⁷ M双氢睾酮（DHT）中2天。AR8细胞的平均神经突长度、分支顺序和神经突场面积呈现雄激素剂量依赖性增加，而神经突分支段长度和胞体面积不受雄激素影响。PC12-WT、NE09和SER8细胞在暴露于DHT时细胞形态未发生改变。由于DHT和NGF的协同作用，评估了DHT对NGF受体mRNA的调节；然而，未记录到雄激素对trkA或p75 mRNA表达有显著诱导作用。结果表明，在AR阳性的PC12细胞中，雄激素与NGF协同作用以增加神经突生长；但雄激素的作用是通过分支和树突化特异性介导的。这些反应与体内雄激素作用的发育研究相似。因此，雄激素似乎在含AR的细胞中诱导了一种内在的神经形态学程序，这增加了这些细胞的感受野，增加了神经间通讯的可能性，尽管并不促进通讯本身。这些细胞系将为研究雄激素 - 神经元相互作用机制提供一个独特的体外系统。
