中华眼镜蛇(Naja Naja Atra)毒神经生长因子对PC_(12)细胞κ阿片受体mRNA表达的影响

Effects of Nerve Growth Factor from Snake Venom(Naja Naja Atra) on expressions of κ opioid receptor mRNA in PC_(12) cells

目的研究眼镜蛇毒神经生长因子(nNGF)对PC12细胞κ阿片受体mRNA表达的影响,探讨nNGF诱导PC12细胞分化的分子机制。方法用RT-PCR方法半定量地考察nNGF及κ阿片受体的一些拮抗剂和激动剂对PC12细胞κ阿片受体mRNA表达的影响。结果(1)在25,50和100 ng/mL 3个nNGF剂量组中,50和100 ng/mL nNGF显著下调PC12细胞κ阿片受体mRNA的表达。(2)50 ng/mL nNGF分别处理PC12细胞1,3,5,7,10 d后,结果显示κ阿片受体mRNA表达随时间有降低的趋势,7 d时显著下调(P<0.05),10 d时特别显著(P<0.01)。(3)10μmol/L吗啡上调PC12细胞κ阿片受体mRNA表达,并能逆转nNGF对该κ阿片受体mRNA表达的下调效应。10μmol/L纳络酮对PC12细胞κ阿片受体的表达无显著影响,也能逆转nNGF对该κ阿片受体mRNA表达的下调效应。但吗啡和纳络酮共存时不能逆转NGF对该κ阿片受体mRNA表达的下调效应。结论nNGF诱导PC12细胞分化时,能下调其κ阿片受体mRNA表达,这种下调能分别被吗啡或纳络酮逆转,但不能被吗啡和纳络酮共存时逆转。

Purpose To examine the effects of Nerve Growth Factor from snake venom （ Naja Naja Atra ） （nNGF） on expression of κ opioid receptor mRNA in PC12 cells, and to probe the molecular mechanism of PC12 cell differentiation induced by nNGF. Methods Semi-quantitatively, to measure the effects of nNGF, some antagonists and agonists on expreesion of κ opioid receptor mRNA in PC12 cells by RT-PCR method. Results （ 1 ） 50 ng/mL or 100 ng/mL nNGF down-regulated expression of κ opioid receptor mRNA significantly among the three dosages of 25 ng/mL, 50 ng/mL and 100 ng/mL. （2） Expression of κ opioid receptor mRNA in PC12 cells displayed down-regulation within 10 days after PC12 cells being added with 50 ng/ml nNGF and were down-regulated significantly in the 7th day（ P 〈 0.05）and in the 10th day very significantly （ P 〈 0.01 ） . （3） 10 μmol/L Morphine up-regulated expression of κ opioid receptor mRNA in PC12 cells and reversed the downregulation of expression of κ opioid receptor mRNA in PCI2 cells induced by nNGF; 10 μmol/L Naloxone didn＇t significantly changed expression of κ opioid receptor mRNA in PC12 cells and also reversed the down-regulation of expression of κ opioid receptor mRNA in PC12 cells induced by nNGF; however, when Morphine together with Naloxone was added, they did not reverse the down-regulation of expression of κ opioid receptor mRNA in PC12 cells induced by nNGF. Conclusion When nNGF induced the differentiation of PC12 cells, down-regulat- ed expression of endogenous κ opioid receptor mRNA in PC12 cells, which was reversed by Morphine or Naloxone, but not by them together.