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

Obesity-associated metabolic dysfunction-associated steatotic liver disease (MASLD) and its progression to steatohepatitis (MASH) with advanced fibrosis pose a major global health challenge. Targeting γ-aminobutyric acid (GABA)ergic system has shown promise in mitigating liver injury. Therefore, we investigated HK3, a positive allosteric modulator of the GABA_A receptor, as a potential therapy for MASH, with a particular focus on liver fibrosis and obesity.

Human-derived 3D MASH spheroids (n = 4-27) 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, reverse-transcription PCR and RNA sequencing. The in vivo effects of HK3 (10 or 25 mg/kg) were evaluated in carbon tetrachloride-induced fibrosis (n = 10) or diet-induced obesity (n = 6-7) mouse models. Adipocytes (3T3-L1, n = 5-8) and visceral adipose tissue from C57BL/6 mice (n = 6) were treated with HK3 or HK1 to determine their impact on mitochondrial respiratory function by extracellular flux analysis and high-resolution respirometry.

The most effective concentration of HK3 reduced intracellular lipid content, interleukin secretion and pro-collagen 1αI levels (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 expression (p <0.0001) and diminished cell migration (p <0.0001). In vivo, HK3 prevented fibrosis progression (p <0.05) in a carbon tetrachloride mouse model and reduced body fat mass (p <0.0001) in a diet-induced obesity mouse model. Accordingly, HK3 increased proton leakage and mitochondrial uncoupling efficiency in adipocytes (p <0.0001) and visceral adipose tissue (p <0.001).

HK3 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.

Obesity-related fatty liver disease can progress to severe liver scarring, yet effective treatments targeting both liver damage and metabolic dysfunction remain rare. 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.