ANALYSIS OF BIOLOGICAL ROLE OD ANTISENSE RNA ON REGULATION OF GENE EXPRESSION

本研究的目的是分析GnRH反义RNA在大鼠下丘脑和其他脑区的存在和生物学作用。为了阐明GnRH反义RNA的作用，我们建立了一种灵敏、特异的检测GnRH反义RNA的方法。利用该方法，我们首次证实了GnRH反义RNA在大鼠下丘脑等脑区的存在。由于GnRH反义RNA与GnRH正义mRNA的比例在下丘脑以外的脑区较高，提示GnRH反义RNA可能抑制了这些脑区的GnRH基因表达。此外，在GnRH类似物处理的大鼠中，研究了下丘脑中GnRH反义RNA和GnRH mRNA水平的变化。GnRH反义RNA的水平在GnRH类似物给药后增加，此后下降。另一方面，GnRH类似物处理后GnRH mRNA水平降低，然后升高。以上结果提示，下丘脑GnRH基因表达可能受到GnRH反义RNA的调控，GnRH反义RNA可能在下丘脑GnRH基因表达调控中起重要作用。然而，GnRH反义RNA的转录调控机制仍有待阐明。目前，我们正针对这些问题，探讨反义RNA的临床应用的可能性。

The aim of the research project is analysis of the presense and biological role of the GnRH antisense RNAs in the rat hypothalamus and the other brain regions. In order to clarify the role, we have established the sensitive- and specific assay for detection of the GnRH antisense RNAs. Using this assay, we firstly demonstrated the presence of the GnRH antisense RNAs in the rat the brain regions including the hypothalamus. Since the ratio of the level of the GnRH antisense RNAs to the GnRH sense mRNA was higher in the brain regions other than the hypothalamus, it was implied that the GnRH antisense RNAs might suppress the gene expression of the GnRH in these region. Furthermore, the changes in the levels of the GnRH antisense RNAs and GnRH mRNA in the hypothalamus were studied in the GnRH analogue-treated rats. The level of the GnRH antisense RNAs increased after the administration of the GnRH analogue, and thereafter decreased. On the other hand, the level of the GnRH mRNA decreased after the GnRH analogue-treatment, and then increased. These results inferred that the gene expression of the GnRH might be regulated, at least in part, by the GnRH antisense RNAs in the hypothalamus.In conclusion, it is indicated that the GnRH antisense RNAs may play some important role in the regulation of the GnRH gene expression. However, it remains to be elucidated that the regulatory mechanism of the transcription of the GnRH antisense RNAs. Now we are addressing these subjects to investigate the possibility of the clinical application of the antisense RNAs.