促离子型谷氨酸受体在正常大鼠下丘脑视前区的表达

Expression of ionotropic glutamate receptors in rat preoptic area of hypothalamus

目的:研究促离子型谷氨酸N-甲基-D-门冬氨酸(N-methyl-D-aspartate,NMDA)受体亚基(NR2A、NR2B、NR1)和α-氨基-3-羟基-5-甲基异恶唑-4-丙酸(Alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid,AMPA)受体亚基(GluR1、GluR2、GluR3、GluR4)在正常大鼠下丘脑视前区(Preoptic area,POA)的表达。方法:分别采用逆转录实时荧光定量PCR和Western blot技术检测成年SD大鼠(n=12)视前区促离子谷氨酸受体亚基。结果:通过逆转录实时荧光定量PCR技术在所有大鼠视前区均可检测到Nr2a、Nr2b、Nr1、Glur1、Glur2和Glur3mRNA,但未检测Glur4 mRNA。在视前区,NMDA受体亚基NR2A mRNA和蛋白表达显著低于NR1(P<0.01),而NR2B和NR1的mRNA、蛋白表达差异无统计学意义(P>0.05);AMPA受体亚基Glur1和Glur3mRNA表达显著低于Glur2 mRNA(P<0.01),而Glur1和Glur3 mRNA的表达丰度差异无统计学意义(P>0.05)。Western blot实验显示,AMPA受体亚基GluR3的蛋白表达明显高于GluR2(P<0.05),但GluR1和GluR2亚基蛋白表达无统计学差异(P>0.05)。结论:在正常大鼠下丘脑视前区中有促离子型谷氨酸NMDA受体和AMPA受体表达,其主要亚基为NR2B、NR1、GluR1、GluR2和GluR3。

Objective:To investigate the expression of subunits of ionotropicglutamate NMDA receptors(NR2A,NR2B,NR1)and AMPA receptors(GluR1,GluR2,GluR3,GluR4)in rat preoptic area(POA)of hypothalamus.Methods:The mRNA and protein levels of NR2A,NR2B,NR1,GluR1,GluR2,GluR3 and GluR4 subunits were measured by reverse transcriptase real-time fluorescence quantitative PCR(qRT-PCR)and Western blot,respectively.Results:The mRNA expressions of Nr2a,Nr2b,Nr1,Glur1,Glur2 and Glur3 in the POA of all the tested rats were detected by qRT-PCR,while Glur4 mRNA was not detected in the POA of 6 rats.The mRNA expression of Nr2a was significantly lower than that of Nr1(P<0.01)as measured by qRT-PCR,while the mRNAs of Nr2b and Nr1 did not show a difference(P>0.05).For AMPA receptors,the mRNAs of Glur1 and Glur3 was significantly less than that of Glur2(P<0.01),but the mRNAs of Glur1 and Glur3 did not show a difference(P>0.05).The expression of protein of NR2A subunit of NMDA receptor was significantly less than that of NR1(P<0.05),while the proteins of NR2B and NR1 subunits had no difference(P>0.05).For protein of AMPA receptor subunits,the expression of GluR3 was significantly up-regulated than GluR2(P<0.05).There was no difference between the expression of GluR1 and GluR2(P>0.05).Conclusion:The expression of ionotropic glutamate NMDA and AMPA receptors is detected in rat POA of hypothalamus.And the major subunits of NMDA and AMPA receptors are NR2B,NR1 and GluR1,GluR2,GluR3,respectively.