Metabolic dysfunction-associated steatohepatitis exacerbated by Clostridium perfringens-derived ammonia is attenuated by tripeptide DT-109

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Abstract

The global prevalence of metabolic dysfunction-associated steatohepatitis (MASH) is rising, driven by a complex interplay of metabolic disturbances, inflammation, and fibrosis, yet effective treatment options remain limited. This study examined the relationships among intestinal microbial dysbiosis, ammonia production, and hepatic CD8+ T cell activity in MASH, and assessed the therapeutic potential of DT-109, a glycine-based tripeptide. We investigated the gut-liver axis across human cohorts and both non-human primate and mouse MASH models. Multi-omics approaches were used to characterize ileal microbiota, ammonia levels, and hepatic immune and metabolic pathways. Causality was verified through microbiota transplantation, C. perfringens NirA-knockout mutants, and functional validation in vitro and in vivo. The efficacy of DT-109 was evaluated in non-human primates and mice. Our results revealed a significant increase in the ammonia-producing gut bacterium C. perfringens, which led to elevated intestinal ammonia and disruption of the intestinal barrier in MASH. Elevated ammonia levels triggered FosB-mediated upregulation of chemokine C-C motif ligand 5 (CCL5) in CD8+ T cells, which in turn drove T cell cytotoxicity in the liver. Notably, DT-109 effectively lowered C. perfringens abundance, reduced intestinal ammonia, restored intestinal barrier integrity, and alleviated CD8+ T cell dysregulation in MASH. These results identify a distinct mechanism in which gut-derived ammonia drives CD8+ T cell-mediated MASH and demonstrate that DT-109 effectively targets this axis by inhibiting C. perfringens and reducing ammonia, ultimately ameliorating MASH.

Authors

Pengxiang Qu, Shusi Ding, Yanru Zhang, Yang Zhao, Erfei Song, Liangshuo Hu, Ruike Ding, Wenbin Cao, Yiting Hou, Jia Qi, Juan Zhao, Chenjing Duan, Shuangqing Liu, Chong Shen, Ying Zhao, Yanhong Guo, Zuowen Zheng, Shiwei Luo, Huizhong Hu, Liang Bai, Sihai Zhao, Bo Wang, Shuixiang He, Yi Wu, Xuelian Xiong, Qiutong Wu, Weiwang Gu, Oren Rom, Aimin Xu, Lemin Zheng, Jifeng Zhang, Enqi Liu, Y. Eugene Chen