摘要
第一部分、AVP4-8调控基因的新途径
AVP4-8是精氨酸加压素在脑内的天然酶解产物,具有促进学习记忆的功能,它能在大鼠脑内引起一系列生理生化反应,RT-PCR结合Southern杂交结果表明,AVP4-8能提高大鼠海马神经元内CTP:磷酸胆碱胞苷转移酶(CCT)的mRNA水平,以及大鼠海马胶质细胞中c-fos的mRNA水平。其拮抗剂ZDC(C)PR能够抑制这一作用。用放线菌素D中止细胞mRNA合成后发现,AVP4-8能提高CCT mRNA和c-fos mRNA的稳定性。这提示转录后水平的调控是AVP4-8影响一些基因mRNA水平的重要手段。
此外,AVP4-8上调海马神经元内CCT mRNA水平导致了其胞内CCT酶活性的上升,从而进一步证明AVP4-8的某些功能是通过与CCT相关的途径来完成的。
Part1. The New Pathways by Which AVP4-8 Regulate Genes
Xu Kanyan ( Biochemistry )
Directed by Prof. Du Yucang
The neuropeptide AVP4-8 is a metabolite of argipressin which has been shown to have potent memory-enhancing activity. It can evoke a series of biophysical and biochemical events in rat brain. Using RT-PCR plus Southern Blot, we found that AVP4-8 could upregulate the mRNA level of CTP: phosphocholine cytidylyltransferase in rat hippocampal neurons and the mRNA level of c-fos in rat hippocampal astrocytes. It's antagonist, ZDC(C)PR could inhibit the process. Using Actinomycin-D to inhibit the cell's transcription, we found AVP4-8 could prolong the halflife of CCT mRNA and c-fos mRNA, which suggesting the role of posttranscriptional regulation in AVP4-8's effect on some genes' mRNA levels.
We also found the upregulation of CCT mRNA led to the increase of enzymatic activity, this further proved the speculation that CCT may play an
important role in some of the AVP4-8 's functions.
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