Molecular Basis for Glucocorticoid Induction of the Kruppel-Like Factor 9 Gene in Hippocampal Neurons
Molecular Basis for Glucocorticoid Induction of the Kruppel-Like Factor 9 Gene in Hippocampal Neurons
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DOI：
10.1210/en.2012-1303
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发表时间：
2012-11-01
期刊：
影响因子：
4.8
通讯作者：
Denver, Robert J.
中科院分区：
文献类型：
--
作者：
Bagamasbad, Pia;Ziera, Tim;Denver, Robert J.
应激对海马结构和功能的影响是复杂的，从而影响学习和记忆。这些作用部分由循环糖皮质激素（GC）介导，其通过细胞内GC受体（GR）和盐皮质激素受体（MR）起作用。在这里，我们研究了GC调节Kruppel样因子9（KLF 9），一个转录因子参与神经元发育和可塑性。注射皮质酮（CORT）在出生后d 6和30小鼠增加Klf 9 mRNA和heterozygosity RNA在海马区1小时。用CORT处理小鼠海马细胞系HT-22引起Klf 9 mRNA的时间和剂量依赖性增加。Klf 9的CORT诱导对蛋白质合成抑制具有抗性，表明Klf 9是直接的CORT反应基因。为了支持这一假设，我们确定了两个GR/MR反应元件（GRE/MRE）位于-6.1和-5.3 kb相对于转录起始位点，我们验证了它们的功能增强子报告，凝胶移位，染色质免疫沉淀试验。约5.3-kb的GRE/MRE在四足动物中很大程度上是保守的，但约6.1-kb的GRE/MRE的保守直向同源物仅在兽目哺乳动物中检测到。GC处理引起GR的募集、组蛋白的超乙酰化和Klf 9上游区域的核小体去除。我们的研究结果支持GR在Klf 9的直接调节中的主要作用，MR的贡献较小，通过位于基因5 '侧翼区域的两个GRE/MRE起作用。KLF 9可能在GC对海马发育和可塑性的影响中起关键作用。（内分泌学153：5334-5345，2012）
Stress has complex effects on hippocampal structure and function, which consequently affects learning and memory. These effects are mediated in part by circulating glucocorticoids (GC) acting via the intracellular GC receptor (GR) and mineralocorticoid receptor (MR). Here, we investigated GC regulation of Kruppel-like factor 9 (KLF9), a transcription factor implicated in neuronal development and plasticity. Injection of corticosterone (CORT) in postnatal d6 and 30 mice increased Klf9 mRNA and heteronuclear RNA by 1 h in the hippocampal region. Treatment of the mouse hippocampal cell line HT-22 with CORT caused a time-and dose-dependent increase in Klf9 mRNA. The CORT induction of Klf9 was resistant to protein synthesis inhibition, suggesting that Klf9 is a direct CORT-response gene. In support of this hypothesis, we identified two GR/MR response elements (GRE/MRE) located -6.1 and -5.3 kb relative to the transcription start site, and we verified their functionality by enhancer-reporter, gel shift, and chromatin immunoprecipitation assays. The -5.3-kb GRE/MRE is largely conserved across tetrapods, but conserved orthologs of the -6.1-kb GRE/MRE were only detected in therian mammals. GC treatment caused recruitment of the GR, histone hyperacetylation, and nucleosome removal at Klf9 upstream regions. Our findings support a predominant role for GR, with a minor contribution of MR, in the direct regulation of Klf9 acting via two GRE/MRE located in the 5'-flanking region of the gene. KLF9 may play a key role in GC actions on hippocampal development and plasticity. (Endocrinology 153:5334-5345, 2012)