In vitro pharmacological characterization of novel isoxazolopyridone derivatives as allosteric metabotropic glutamate receptor 7 antagonists
In vitro pharmacological characterization of novel isoxazolopyridone derivatives as allosteric metabotropic glutamate receptor 7 antagonists
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DOI：
10.1124/jpet.107.124701
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发表时间：
2007-10-01
影响因子：
3.5
通讯作者：
Ohta, Hisashi
中科院分区：
文献类型：
--
作者：
Suzuki, Gentaroh;Tsukamoto, Naohiro;Ohta, Hisashi
新的异恶唑并吡啶酮衍生物，代谢型谷氨酸受体（mGluR）7拮抗剂被发现，并进行了初步表征。对5-甲基-3，6-二苯基异恶唑并[4，5-c]吡啶-4（5 H）-酮（MDIP）进行了结构鉴定，并对MDIP进行化学修饰，得到6-（4-甲氧基苯基）-5-甲基-3-吡啶-4-基异恶唑并[4，5-c]吡啶-4（5 H）-酮（MMPIP）。MDIP和MMPIP可抑制L-（+）-2-氨基-4-膦酰基丁酸（L-AP 4）诱导的共表达大鼠mGluR 7和G α的中国仓鼠卵巢（CHO）细胞内Ca 2+动员（15）（IC 50 = 20和26 nM）。MMPIP存在时，激动剂浓度-反应曲线中的最大反应降低，且其拮抗作用是可逆的。MMPIP未置换与mGluR 7结合的[H-3]（2S）-2-氨基-2-[（1 S，2S）-2-羧基环丙基]-3-（黄嘌呤-9-基）丙酸（LY 341495）。这些结果表明，这些异恶唑吡啶酮衍生物是变构拮抗剂。在表达大鼠mGluR 7的CHO细胞中，MDIP和MMPIP可抑制L-AP 4诱导的毛喉素刺激cAMP蓄积抑制（IC 50 = 99和220 nM）。共表达人mGluR 7与G α（15）、MDIP和MMPIP的CHO细胞也抑制L-AP 4诱导的cAMP反应。在cAMP测定中，MMPIP的最大抑制程度高于MDIP。MMPIP能够拮抗变构激动剂N，N '-二苯甲基-乙烷-1，2-二胺二盐酸盐（AMN 082）诱导的cAMP蓄积抑制。在这些激动剂的情况下，MMPIP引起进一步增加毛喉素刺激的cAMP水平在CHO细胞表达mGluR 7，而竞争性拮抗剂，LY 341495，没有。该结果表明MMPIP具有反向激动活性。MMPIP的内在活性是百日咳毒素敏感的和mGluR 7依赖的。浓度至少为1 μ M的MMPIP对mGluR 1、mGluR 2、mGluR 3、mGluR 4、mGluR 5和mGluR 8没有显著影响。MMPIP是第一个变构mGluR 7选择性拮抗剂，可能作为阐明mGluR 7对中枢神经系统功能作用的药理学工具。
Novel isoxazolopyridone derivatives that are metabotropic glutamate receptor (mGluR) 7 antagonists were discovered and pharmacologically characterized. 5-Methyl-3,6-diphenylisoxazolo[4,5-c] pyridin-4(5H)-one(MDIP) was identified by random screening, and 6-(4-methoxyphenyl)-5-methyl-3-pyridin-4-ylisoxazolo[4,5-c]pyridin-4( 5H)-one ( MMPIP) was produced by chemical modification of MDIP. MDIP and MMPIP inhibited L-(+)-2-amino-4-phosphonobutyric acid (L-AP4)-induced intracellular Ca2+ mobilization in Chinese hamster ovary (CHO) cells coexpressing rat mGluR7 with G alpha(15) (IC50 = 20 and 26 nM). The maximal response in agonist concentration-response curves was reduced in the presence of MMPIP, and its antagonism is reversible. MMPIP did not displace [H-3](2S)-2-amino-2-[(1S,2S)-2-carboxycycloprop1-yl]-3-(xanth-9-yl) propanoic acid (LY341495) bound to mGluR7. These results suggested that these isoxazolopyridone derivatives are allosteric antagonists. In CHO cells expressing rat mGluR7, MDIP and MMPIP inhibited L-AP4-induced inhibition of forskolin-stimulated cAMP accumulation (IC50 = 99 and 220 nM). CHO cells coexpressing human mGluR7 with G alpha(15), MDIP and MMPIP also inhibited the L-AP4-induced cAMP response. The maximal degree of inhibition by MMPIP was higher than that by MDIP in a cAMP assay. MMPIP was able to antagonize an allosteric agonist, the N,N'-dibenzhydryl-ethane-1,2-diamine dihydrochloride (AMN082)-induced inhibition of cAMP accumulation. In the absence of these agonists, MMPIP caused a further increase in forskolin-stimulated cAMP levels in CHO cells expressing mGluR7, whereas a competitive antagonist, LY341495, did not. This result indicates that MMPIP has an inverse agonistic activity. The intrinsic activity of MMPIP was pertussis toxin-sensitive and mGluR7-dependent. MMPIP at concentrations of at least 1 mu M had no significant effect on mGluR1, mGluR2, mGluR3, mGluR4, mGluR5, and mGluR8. MMPIP is the first allosteric mGluR7-selective antagonist that could potentially be useful as a pharmacological tool for elucidating the roles of mGluR7 on central nervous system functions.