Perlman W R, Matsumoto M, Beltaifa S, Hyde T M, Saunders R C, Webster M J, Rubinow D R, Kleinman J E, Weickert C S
Clinical Brain Disorders Branch, National Institute of Mental Health, National Institutes of Health, United States Department of Health and Human Services, Bethesda, MD 20892-1385, USA.
Neuroscience. 2005;134(1):81-95. doi: 10.1016/j.neuroscience.2005.03.055.
Although estrogen receptor alpha (ERalpha) mRNA has been detected in the primate frontal cortex, the types of ERalpha transcripts expressed, including exon-deleted variants (Delta), have not been determined in the monkey or human frontal cortex. Because the types of ERalpha mRNA expressed in brain could define neuronal responses to estrogens, we examined the transcript pool of ERalpha mRNAs expressed in normal adult and developing human and macaque frontal cortex. We reverse transcribed total RNA from the postmortem frontal cortex of 29 normal adult humans, 12 rhesus macaques, and 19 people ranging from infants to adults and employed two rounds of nested polymerase chain reaction (PCR) to generate ERalpha products spanning the coding domain. In a third nested PCR, we used primers specific for novel sequences of exon-exon junctions created when whole exons are missing. By sequencing PCR products, we detected 60 instances of 12 distinct DeltaERalpha mRNAs in adult humans and 94 instances of 13 distinct DeltaERalpha mRNAs in monkeys in differing patterns from one individual to another. In adult humans, 83% of individuals expressed at least 1 DeltaERalpha mRNA variant, and 100% of the monkeys expressed at least 1 DeltaERalpha mRNA variant. The single Delta2, Delta5, and Delta7 variants were frequently expressed in both human and monkey frontal cortex, Delta3 variants were rare in both species, and Delta6 variants were more frequently expressed in monkeys. In both species, we detected double, triple and quadruple Deltas, but these were less common than single Deltas. The pattern of human variant expression did not appear to change dramatically as a function of age. These findings imply the potential to produce different ERalpha proteins in frontal cortex, possibly with altered structure and function which may have physiological relevance for gene transcription by virtue of altered functional interactions with each other, other steroid hormone receptors, and genomic DNA.
虽然在灵长类动物额叶皮质中已检测到雌激素受体α（ERα）mRNA，但在猴子或人类额叶皮质中尚未确定所表达的ERα转录本类型，包括外显子缺失变体（Delta）。由于大脑中表达的ERα mRNA类型可以定义神经元对雌激素的反应，我们研究了正常成年和发育中的人类及猕猴额叶皮质中表达的ERα mRNA转录本库。我们从29名正常成年人、12只恒河猴以及19名从婴儿到成年人的人类的死后额叶皮质中反转录总RNA，并采用两轮巢式聚合酶链反应（PCR）来生成跨越编码域的ERα产物。在第三次巢式PCR中，我们使用了针对全外显子缺失时产生的外显子 - 外显子连接新序列的引物。通过对PCR产物进行测序，我们在成年人类中检测到12种不同的DeltaERα mRNA的60个实例，在猴子中检测到13种不同的DeltaERα mRNA的94个实例，个体之间的模式各不相同。在成年人类中，83%的个体表达至少1种DeltaERα mRNA变体，100%的猴子表达至少1种DeltaERα mRNA变体。单一的Delta2、Delta5和Delta7变体在人类和猴子额叶皮质中均频繁表达，Delta3变体在两个物种中均罕见，Delta6变体在猴子中更频繁表达。在两个物种中，我们都检测到双、三、四重Delta，但这些比单一Delta少见。人类变体表达模式似乎并未随年龄发生显著变化。这些发现意味着额叶皮质有可能产生不同的ERα蛋白，其结构和功能可能发生改变，这可能由于它们彼此之间、与其他类固醇激素受体以及基因组DNA的功能相互作用改变而对基因转录具有生理相关性。
