D'Sa Carrol, Tolbert Lara M, Conti Marco, Duman Ronald S
Laboratory of Molecular Psychiatry, Departments of Psychiatry and Pharmacology, Yale University School of Medicine, Connecticut Mental Health Center, 34 Park Street, New Haven, CT 06508, USA.
J Neurochem. 2002 May;81(4):745-57. doi: 10.1046/j.1471-4159.2002.00878.x.
This study examined the regulation of all known phosphodiesterase (PDE) type PDE4A, PDE4B and PDE4D splice variants in cortical neurons by cAMP signaling. Treatment with dibutyryl-cAMP (db-cAMP) caused the induction of two of the known splice variants, PDE4B2 and PDE4D1/PDE4D2. Although the splice variants PDE4A1, PDE4A5/PDE4A10, PDE4B3, PDE4B1, PDE4D3 and PDE4D4 were present in cortical neurons, their mRNA was not regulated at the transcriptional level by db-cAMP. To assess the increase in PDE4B2 and PDE4D1/D2 mRNA expression, the promoters containing these genes were characterized. Transcription from both promoters was stimulated by db-cAMP. Because chronic antidepressant treatment increases PDE4B, and not PDE4D, mRNA expression, we focused on the regulation of the PDE4B2 promoter by cAMP and CREB. Dominant negative mutants of CREB suppressed PDE4B2 promoter activity and a constitutively active form of CREB robustly stimulated it. These data demonstrate that in cortical neurons, a short PDE4B2 intronic promoter is regulated by CREB, confers cAMP responsitivity and directs PDE4B2 mRNA and protein expression.
本研究通过环磷酸腺苷（cAMP）信号通路检测了皮质神经元中所有已知的磷酸二酯酶（PDE）4A、4B和4D剪接变体的调控情况。用二丁酰环磷腺苷钙（db - cAMP）处理可诱导出两种已知的剪接变体，即PDE4B2和PDE4D1/PDE4D2。尽管剪接变体PDE4A1、PDE4A5/PDE4A10、PDE4B3、PDE4B1、PDE4D3和PDE4D4存在于皮质神经元中，但其mRNA在转录水平不受db - cAMP调控。为评估PDE4B2和PDE4D1/D2 mRNA表达的增加情况，对含有这些基因的启动子进行了表征。db - cAMP可刺激这两个启动子的转录。由于慢性抗抑郁治疗可增加PDE4B而非PDE4D的mRNA表达，我们重点研究了cAMP和CREB对PDE4B2启动子的调控。CREB的显性负性突变体抑制了PDE4B2启动子活性，而一种组成型活性形式的CREB则强烈刺激了它。这些数据表明，在皮质神经元中，一个短的PDE4B2内含子启动子受CREB调控，赋予cAMP反应性并指导PDE4B2 mRNA和蛋白表达。
