Mechanism of Retinoid X Receptor Partial Agonistic Action of 1-(3,5,5,8,8-Pentamethyl-5,6,7,8-tetrahydro-2-naphthyl)-1H-benzotriazole-5-carboxylic Acid and Structural Development To Increase Po

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• 作者：Fuminori Ohsawa ; Shoya Yamada ; Nobumasa Yakushiji ; Ryosuke Shinozaki ; Mariko Nakayama ; Kohei Kawata ; Manabu Hagaya ; Toshiki Kobayashi ; Kazutaka Kohara ; Yuuki Furusawa ; Chisa Fujiwara ; Yui Ohta ; Makoto Makishima ; Hirotaka Naitou ; Akihiro Tai ; Yutaka Yoshikawa ; Hiroyuki Yasui ; Hiroki Kakuta
• 刊名：Journal of Medicinal Chemistry
• 出版年：2013
• 出版时间：March 14, 2013
• 年：2013
• 卷：56
• 期：5
• 页码：1865-1877
• 全文大小：523K
• 年卷期：v.56,no.5(March 14, 2013)
• ISSN：1520-4804

文摘

We have reported that retinoid X receptor (RXR) partial agonist 1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2-naphthyl)-1H-benzotriazole-5-carboxylic acid (CBt-PMN, 4a) shows a significant antidiabetes effect in the KK-A^y type 2 diabetes model mice, with reduced side effects compared to RXR full agonists. To elucidate the mechanism of the RXR partial agonist activity of 4a, we synthesized derivatives of 4a, evaluated their RXR agonist activity, and performed structure鈥揳ctivity relationship analysis. Reporter gene assay revealed that though 6b, which possesses an amino group at the 2-position of 5-carboxybenzimidazole, showed RXR full-agonist activity, compounds 6d and 6e, which possess an oxygen atom and a sulfur atom at the corresponding position, respectively, showed weak RXR agonist activity. On the other hand, 6c, which has a trifluoromethyl group at the corresponding position, acts as an RXR partial agonist, having similar E_max (67 卤 2%) and lower EC₅₀ (15 卤 0 nM) compared to those of 4a (E_max = 75 卤 4%, EC₅₀ = 143 卤 2 nM). A fluorescence polarization assay of cofactor recruitment confirmed that fluorescein-labeled D22 coactivator peptide was less efficiently recruited to RXR by 4a and 6c than by LGD1069 (1), a known RXR full agonist. Electrostatic potential field calculations and computational docking studies suggested that full agonists show an electrostatic attraction, which stabilizes the holo structure and favors coactivator recruitment, between the side chain at the benzimidazole 2-position and the 伪-carbonyl oxygen of asparagine-306 in helix 4 (H4) of the RXR receptor. However, RXR partial agonists 4a and 6c lack this interaction. Like 4a, 6c showed a significant antidiabetes effect in KK-A^y type 2 diabetes model mice with reduced levels of the side effects associated with RXR full agonists. These findings should aid the design of new RXR partial agonists as antitype 2 diabetes drug candidates.