A thioacrylamide-based compound directly counteracts hepatic fibrosis with profound anti-obesity action

Background
Obesity-associated MASLD and its progression towards MASH-related advanced fibrosis is a growing global health concern. Targeting γ-aminobutyric acid type A (GABA) signaling has shown promise in mitigating liver injury. Therefore, we investigated the novel compound HK3, a positive allosteric modulator of the GABAA receptor, for treating MASH with a particular focus on liver fibrosis and obesity.
Methods
Human-derived 3D MASH spheroids and hepatic stellate cells (LX2, n=3-5) were treated with increasing concentrations of HK3 or its derivative HK1 to assess their anti-steatotic, anti-inflammatory and anti-fibrotic efficacy. Molecular and transcriptional responses were assessed by immunoblotting, ELISA, RT-PCR and RNA sequencing. The in vivo effects of HK3 (10 or 25 mg/kg) were evaluated in a CCl4-induced fibrosis (n=10) or a diet-induced obesity (DIO, n=6-7) mouse model. Adipocytes (3T3-L1, n=5-8) and visceral adipose tissue (VAT) from C57BL/6 mice (n=6) were treated with HK3 or HK1 to determine their impact on mitochondrial respiratory function by extracellular flux analysis or high-resolution respirometry.
Results
The most effective concentration of HK3 reduced intracellular lipid content, interleukin secretion and pro-collagen 1αI level (p<0.0001, p<0.05, p<0.01) in the organotypic 3D human MASH model. In hepatic stellate cells, HK3 and HK1 dose dependently attenuated TGF-β1-induced fibrotic, and inflammatory biomarker expressions (p<0.0001) and diminished cell migration (p<0.0001). In vivo, HK3 prevented fibrosis progression (p<0.05) in a CCl4 mouse model and reduced body fat mass (p<0.0001) in a DIO mouse model. In line, HK3 increased proton leakage and mitochondrial uncoupling efficiency in adipocytes (p<0.0001) and VAT (p<0.001).ConclusionHK3 attenuates hepatic fibrosis in preclinical MASH models, while reducing body fat through adipocyte mitochondrial uncoupling. Thus, HK3 offers a promising multi-targeted first-in-class pharmacological approach for obesity-associated MASLD.Impact and implications/ Lay summary: Obesity-related fatty liver disease can progress to severe liver scarring, yet effective treatments targeting both liver damage and metabolic dysfunction are still lacking. This study investigates HK3, a novel small molecule, which reduced liver fat, inflammation, and scarring while also lowering body fat in multiple preclinical models. These findings are particularly relevant for patients with obesity-related fatty liver disease, where current therapies often fail to adequately address fibrosis, the main driver of disease progression. If confirmed in clinical studies, HK3 could support the development of multi-target treatments that simultaneously improve liver health and metabolic balance.