Structural optimization of anti-hypoxic candidates guided by FGF21 and GDF15 mRNA expression

Therapeutics for acute mountain sickness (AMS) remain limited, with no new drugs introduced since acetazolamide over half a century ago. Recently, H0802, whose target protein was unknown, was an FGF21 and GDF15 mRNA Expression regulator with promising anti-hypoxic effects. Given that FGF21 and GDF15 have been identified as key factors in hypoxia-related metabolic reprogramming, this study proposes a drug-discovery approach based on the RNA-regulation phenotypes of FGF21 and GDF15 to explore the structure-activity relationship of H0802. We designed and synthesized 28 new compounds and tested them on primary liver cells using mRNA expression of FGF21 and GDF15 as indicators. YXX0237 and YXX0248 emerged as the most promising candidates. They significantly increased FGF21 and GDF15 levels both in vitro and in vivo, thereby enhancing mice's hypoxia tolerance in closed hypoxia experiments. Preliminary safety tests showed that YXX0237 and YXX0248 have favorable safety profiles, with low cytotoxicity within the effective dose range, and their LD₅₀ values in mice exceed 500 mg/kg. Pharmacokinetic studies revealed that YXX0237 has higher bioavailability than YXX0248, enters the bloodstream quickly, and maintains stable exposure. Overall, this research offers a new strategy for developing small molecules that enhance hypoxia tolerance by inducing the expression of FGF21 and GDF15. Structure-activity relationship analysis provides a foundation for further structural optimization of H0802 derivatives. YXX0237 could be a potential candidate for treating hypoxia-related diseases.