Severe myoclonic epilepsy of infancy (SMEI, Dravet syndrome), which is mainly caused by the SCN1A mutation, is a severe epileptic encephalopathy that manifests in infancy and leads to intractable seizures and developmental impairment. To discover new therapeutic chemotypes, we established a Nav1.1 (scn1lab) KO zebrafish model for chemical screening and identified novel 1,3,4-oxadiazol-2(3H)-one derivatives. Among them, compound 20e showed the most potent antiseizure efficacy in zebrafish behavioral assays and significantly reduced locomotion-related seizure parameters compared with repositioned drugs. In SCN1A^+/- mice, 20e reduced seizure severity, delayed onset, and suppressed hyperactivity. Notably, 20e normalized pathological spike and burst activity in SMEI patient-derived iPSC neurons. Mechanistically, 20e appears to elevate 5-HT levels via TPH2 upregulation. It demonstrated reasonable BBB penetration, favorable oral PK, and good safety without notable hERG inhibition, cytotoxicity, mutagenicity, or acute toxicity. Taken together, compound 20e shows promise as a therapeutic agent for SMEI.

Background: Aryl hydrocarbon receptor (AhR) is a transcription factor that is involved in the regulation of immunity. AhR inhibits T cell activation in tumors, which induces immune suppression in the blood and solid tumors. We identified effective small-molecule AhR antagonists for cancer immunotherapy. Methods: A new series of pyrazolopyrimidine derivatives was synthesized and evaluated for AhR antagonistic activity. Results: Compound 7k exhibited significant antagonistic activity against AhR in a transgenic zebrafish model. In addition, 7k exhibited good AhR antagonist activity, with a half-maximal inhibitory concentration (IC₅₀) of 13.72 nM. Compound 7k showed a good pharmacokinetic profile with an oral bioavailability of 71.0% and a reasonable half-life of 3.77 h. Compound 7k selectively exerted anti-proliferative effects on colorectal cancer cells without affecting normal cells, concurrently suppressing the expression of AhR-related genes and the PD-1/PD-L1 signaling pathway. Compound 7k exhibited potent antitumor activity in syngeneic colorectal cancer models. Importantly, the combination of anti-PD1 and compound 7k enhanced antitumor immunity by augmenting cytotoxic T lymphocyte (CTL)-mediated activity. Conclusions: Collectively, a new pyrazolopyrimidine derivative, 7k, shows promise as a potential therapeutic agent for treating colorectal cancer.

Dravet syndrome (DS) is a severe, catastrophic childhood epilepsy predominantly caused by loss-of-function mutations in the SCN1A gene, which encodes the voltage-gated sodium channel Na_v1.1. In this study, we evaluated the therapeutic potential of 5-(Benzofuran-2-yl)-3-(2-chloro-4-fluorobenzyl)-1,3,4-oxadiazol-2(3H)-one (GM-90663), a novel small molecule designed to address the complex pathophysiology of DS. Using scn1lab knockout (KO) zebrafish larvae—a robust vertebrate model for DS—we demonstrated that GM-90663 significantly alleviates seizure-like behavioral movements and rescues deficit in cognitive-like functions. Whole-cell patch-clamp recordings in hippocampal slices revealed that GM-90663 modulates voltage-gated Na⁺ channel kinetics; specifically, it suppresses slow ramp-induced currents, thereby effectively attenuating neuronal hyperexcitability. Furthermore, neurochemical profiling indicated that GM-90663 treatment leads to a marked increase in endogenous serotonin (5-HT) levels in both wild-type and KO larvae. Molecular docking simulations and subsequent in vitro enzymatic assays confirmed that this elevation in serotonin is mediated through the potent inhibition of monoamine oxidase (MAO) activity. Collectively, our findings suggest that GM-90663 exerts its anti-seizure effects through a synergistic dual mechanism—stabilizing sodium channel conductance and elevating serotonergic activity—positioning it as a promising multi-target candidate for the treatment of DS.

Pathological platelet activation is central to cardiovascular disorders. Glycoprotein VI (GPVI), a pivotal collagen receptor, is a promising antithrombotic target. While earlier studies focused on the downstream effects of peroxisome proliferator-activated receptor γ (PPARγ) ligands, we recently identified the proximal PPARγ-Src family kinase (SFK) interaction as a key regulatory node. KR-62980 is a novel non-thiazolidinedione (non-TZD) PPARγ modulator designed to minimize traditional TZD-associated adverse effects. Here, we investigated whether KR-62980 operates through this "proximal mechanism." We found that KR-62980 dose-dependently inhibited collagen-induced human platelet aggregation in both washed platelets and platelet-rich plasma. Notably, KR-62980 exhibited a predominant sensitivity toward the collagen-GPVI axis compared to thrombin-induced protease-activated receptor signaling. Mechanistically, KR-62980 targeted the top of the GPVI signaling hierarchy by disrupting the physical and functional association between PPARγ and SFKs (Lyn and Fyn). This blockade suppressed SFK autophosphorylation and dismantled the LAT signalosome, preventing the recruitment of Gads, SLP-76, Btk, and PLCγ2. These findings confirm that the "proximal interaction" paradigm is a universal feature of PPARγ-mediated antiplatelet action, regardless of the agonist's chemical structure. In vivo, oral administration of KR-62980 significantly prolonged thrombotic occlusion time in a mouse carotid artery thrombosis model. Importantly, at therapeutic doses, KR-62980 did not significantly affect tail bleeding time, demonstrating a favorable safety profile with a wide therapeutic window. These findings confirm that the "proximal interaction" paradigm is a universal feature of PPARγ-mediated antiplatelet action and suggest that KR-62980 is a promising candidate for safe antithrombotic therapy.