Cell. 2024 Oct 24:S0092-8674(24)01149-8.

 doi: 10.1016/j.cell.2024.10.001. Online ahead of print.

Structure-guided discovery of bile acid derivatives for treating liver diseases without causing itch

Jun Yang ¹, Tianjun Zhao ², Junping Fan ³, Huaibin Zou ⁴, Guangyi Lan ⁵, Fusheng Guo ¹, Yaocheng Shi ³, Han Ke ³, Huasheng Yu ⁶, Zongwei Yue ¹, Xin Wang ⁷, Yingjie Bai ⁷, Shuai Li ⁸, Yingjun Liu ⁸, Xiaoming Wang ⁸, Yu Chen ⁹, Yulong Li ¹⁰, Xiaoguang Lei ¹¹

• PMID: 39476841
• DOI: 10.1016/j.cell.2024.10.001

Abstract

Chronic itch is a debilitating symptom profoundly impacting the quality of life in patients with liver diseases like cholestasis. Activation of the human G-protein coupled receptor, MRGPRX4 (hX4), by bile acids (BAs) is implicated in promoting cholestasis itch. However, the detailed underlying mechanisms remain elusive. Here, we identified 3-sulfated BAs that are elevated in cholestatic patients with itch symptoms. We solved the cryo-EM structure of hX4-Gq in a complex with 3-phosphated deoxycholic acid (DCA-3P), a mimic of the endogenous 3-sulfated deoxycholic acid (DCA-3S). This structure revealed an unprecedented ligand-binding pocket in MRGPR family proteins, highlighting the crucial role of the 3-hydroxyl (3-OH) group on BAs in activating hX4. Guided by this structural information, we designed and developed compound 7 (C7), a BA derivative lacking the 3-OH. Notably, C7 effectively alleviates hepatic injury and fibrosis in liver disease models while significantly mitigating the itch side effects.

Keywords: 3-sulfonated bile acids; MRGPRX4; OCA; bile acids; cholestatic pruritus; cryo-EM structure; deoxycholic acid; farnesoid X receptor; liver diseases; non-alcoholic steatohepatitis.