Xiao Yingxian, Abdrakhmanova Galya R, Baydyuk Maryna, Hernandez Susan, Kellar Kenneth J
Department of Pharmacology, Georgetown University School of Medicine, Washington, DC 20057, USA.
Acta Pharmacol Sin. 2009 Jun;30(6):842-50. doi: 10.1038/aps.2009.69. Epub 2009 May 18.
To compare pharmacological properties of heterologously expressed homomeric alpha7 nicotinic acetylcholine receptors (alpha7 nAChRs) with those of native nAChRs containing alpha7 subunit (alpha7* nAChRs) in rat hippocampus and cerebral cortex.
We established a stably transfected HEK-293 cell line that expresses homomeric rat alpha7 nAChRs. We studies ligand binding profiles and functional properties of nAChRs expressed in this cell line and native rat alpha7* nAChRs in rat hippocampus and cerebral cortex. We used [(125)I]-alpha-bungarotoxin to compare ligand binding profiles in these cells with those in rat hippocampus and cerebral cortex. The functional properties of the alpha7 nAChRs expressed in this cell line were studied using whole-cell current recording.
The newly established cell line, KXalpha7R1, expresses homomeric alpha7 nAChRs that bind [(125)I]-alpha-bungarotoxin with a K(d) value of 0.38+/-0.06 nmol/L, similar to K(d) values of native rat alpha7* nAChRs from hippocampus (K(d)=0.28+/-0.03 nmol/L) and cerebral cortex (K(d)=0.33+/-0.05 nmol/L). Using whole-cell current recording, the homomeric alpha7 nAChRs expressed in the cells were activated by acetylcholine and (-)-nicotine with EC(50) values of 280+/-19 micromol/L and 180+/-40 micromol/L, respectively. The acetylcholine activated currents were potently blocked by two selective antagonists of alpha7 nAChRs, alpha-bungarotoxin (IC(50)=19+/-2 nmol/L) and methyllycaconitine (IC(50)=100+/-10 pmol/L). A comparative study of ligand binding profiles, using 13 nicotinic ligands, showed many similarities between the homomeric alpha7 nAChRs and native alpha7* receptors in rat brain, but it also revealed several notable differences.
This newly established stable cell line should be very useful for studying the properties of homomeric alpha7 nAChRs and comparing these properties to native alpha7* nAChRs.
比较异源表达的同聚体α7烟碱型乙酰胆碱受体（α7 nAChRs）与大鼠海马体和大脑皮层中含α7亚基的天然nAChRs（α7* nAChRs）的药理学特性。
我们建立了一个稳定转染的HEK - 293细胞系，该细胞系表达同聚体大鼠α7 nAChRs。我们研究了该细胞系中表达的nAChRs以及大鼠海马体和大脑皮层中天然大鼠α7* nAChRs的配体结合谱和功能特性。我们使用[（125）I] - α - 银环蛇毒素来比较这些细胞与大鼠海马体和大脑皮层中的配体结合谱。使用全细胞电流记录研究了该细胞系中表达的α7 nAChRs的功能特性。
新建立的细胞系KXα7R1表达同聚体α7 nAChRs，其与[（125）I] - α - 银环蛇毒素结合的K（d）值为0.38±0.06 nmol/L，与大鼠海马体（K（d） = 0.28±0.03 nmol/L）和大脑皮层（K（d） = 0.33±0.05 nmol/L）中天然大鼠α7* nAChRs的K（d）值相似。使用全细胞电流记录，细胞中表达的同聚体α7 nAChRs分别被乙酰胆碱和（ - ） - 尼古丁激活，其EC（50）值分别为280±19 μmol/L和180±40 μmol/L。乙酰胆碱激活的电流被α7 nAChRs的两种选择性拮抗剂α - 银环蛇毒素（IC（50） = 19±2 nmol/L）和甲基lycaconitine（IC（50） = 100±10 pmol/L）有效阻断。使用13种烟碱配体进行的配体结合谱比较研究表明，同聚体α7 nAChRs与大鼠脑中的天然α7*受体之间有许多相似之处，但也揭示了一些显著差异。
这个新建立的稳定细胞系对于研究同聚体α7 nAChRs的特性并将这些特性与天然α7* nAChRs进行比较应该非常有用。
