No approved therapies are available for nonalcoholic steatohepatitis (NASH). Adenosine monophosphate-activated protein kinase (AMPK) is a central regulator of cell metabolism; its activation has been suggested as a therapeutic approach to NASH. Here we aimed to fully characterize the potential for direct AMPK activation in preclinical models and to determine mechanisms that could contribute to efficacy for this disease. A novel small-molecule direct AMPK activator, PXL770, was used. Enzyme activity was measured with recombinant complexes. De novo lipogenesis (DNL) was quantitated in vivo and in mouse and human primary hepatocytes. Metabolic efficacy was assessed in ob/ob and high-fat diet-fed mice. Liver histology, biochemical measures, and immune cell profiling were assessed in diet-induced NASH mice. Direct effects on inflammation and fibrogenesis were assessed using primary mouse and human hepatic stellate cells, mouse adipose tissue explants, and human immune cells. PXL770 directly activated AMPK in vitro and reduced DNL in primary hepatocytes. In rodent models with metabolic syndrome, PXL770 improved glycemia, dyslipidemia, and insulin resistance. In mice with NASH, PXL770 reduced hepatic steatosis, ballooning, inflammation, and fibrogenesis. PXL770 exhibited direct inhibitory effects on pro-inflammatory cytokine production and activation of primary hepatic stellate cells. Conclusion: In rodent models, direct activation of AMPK is sufficient to produce improvements in all core components of NASH and to ameliorate related hyperglycemia, dyslipidemia, and systemic inflammation. Novel properties of direct AMPK activation were also unveiled: improved insulin resistance and direct suppression of inflammation and fibrogenesis. Given effects also documented in human cells (reduced DNL, suppression of inflammation and stellate cell activation), these studies support the potential for direct AMPK activation to effectively treat patients with NASH. (Hepatology Communications 2021;0:1-19). N onalcoholic fatty liver disease (NAFLD) is the most common hepatic disorder worldwide. Overnutrition and a sedentary lifestyle are principal causes; however, onset and progression are influenced by other factors such as genetics and comorbid conditions. (1)

Introduction Imeglimin, a glucose‐lowering agent targeting mitochondrial bioenergetics, decreases reactive oxygen species (ROS) overproduction and improves glucose homeostasis. We investigated whether this is associated with protective effects on metabolic syndrome‐related left ventricular (LV) and vascular dysfunctions. Methods We used Zucker fa/fa rats to assess the effects on LV function, LV tissue perfusion, LV oxidative stress and vascular function induced by imeglimin administered orally for 9 or 90 days at a dose of 150 mg/kg twice daily. Results Compared to untreated animals, 9‐ and 90‐day imeglimin treatment decreased LV end‐diastolic pressure and LV end‐diastolic pressure‐volume relation, increased LV tissue perfusion and decreased LV ROS production. Simultaneously, imeglimin restored acetylcholine‐mediated coronary relaxation and mesenteric flow‐mediated dilation. One hour after imeglimin administration, when glucose plasma levels were not yet modified, imeglimin reduced LV mitochondrial ROS production and improved LV function. Ninety‐day imeglimin treatment reduced related LV and kidney fibrosis and improved kidney function. Conclusion In a rat model, mimicking Human metabolic syndrome, imeglimin immediately countered metabolic syndrome‐related cardiac diastolic and vascular dysfunction by reducing oxidative stress/increased NO bioavailability and improving myocardial perfusion and after 90‐day treatment myocardial and kidney structure, effects that are, at least in part, independent from glucose control.

Summary AMPK is an energy sensor modulating metabolism, inflammation, and a target for metabolic disorders. Metabolic dysfunction results in lower AMPK activity. PXL770 is a direct AMPK activator, inhibiting de novo lipogenesis (DNL) and producing efficacy in preclinical models. We aimed to assess pharmacokinetics, safety, and pharmacodynamics of PXL770 in humans with metabolic syndrome-associated fatty liver disease. In a randomized, double-blind four-week trial, 12 overweight/obese patients with non-alcoholic fatty liver disease (NAFLD) and insulin resistance received PXL770 500 mg QD; 4 subjects received matching placebo. Endpoints included pharmacokinetics, hepatic fractional DNL, oral glucose tolerance testing, additional pharmacodynamic parameters, and safety. PK parameters show adequate plasma exposure in NAFLD patients for daily oral dosing. PXL770 decreases DNL—both peak and AUC are reduced versus baseline—and improves glycemic parameters and indices of insulin sensitivity versus baseline. Assessment of specific lipids reveals decrease in diacyglycerols/triacylglycerols. Safety/tolerability are similar to placebo. These results unveil initial human translation of AMPK activation and support this therapeutic strategy for metabolic disorders.

Introduction AMPK is a central energy sensor with cardioprotective effects, and its activation has emerged as a target for the treatment of metabolic syndrome-related cardiac dysfunction. PXL770 is the first direct AMPK activator under clinical development, currently investigated for the treatment of NASH. Since potential cardiac benefits of PXL770 have not been previously assessed we investigated whether short- and long-term PXL770 treatment exerts protective cardiac effects in rats with metabolic syndrome. Methods ZSF-1 rats were treated with PXL770 (150 mg/kg orally BID for 90 days initiated at the age of 12 weeks, or for 7 days initiated at the age of 23 weeks) in order to determine left ventricular (LV) function and remodeling. Results After 90 days, untreated ZSF-1 rats showed signs of LV diastolic dysfunction, illustrated by the increase in LV end-diastolic pressure (LV EDP; 5.58±0.57 and 8.28±1.02 mmHg in lean and ZSF-1 rats, respectively; p<0.05) and in LV end-diastolic pressure volume-relation (LV EDPVR; 1.10±0.23 and 5.44±0.65 mmHg/RVU in lean and ZSF-1 rats, respectively; p<0.05) with preserved LV systolic function, illustrated by the slight decrease in LV fractional shortening (LV FS; 46±1 and 42±1% in lean and ZSF-1 rats, respectively; p<0.05) and similar LV end-systolic pressure (LV ESP; 173±10 and 197±6 mmHg, respectively) or LV end-systolic pressure volume-relation (LV ESPVR; 32.7±4.2 to 28.6±1.4 mmHg/RVU, respectively). LV diastolic dysfunction was associated with a significant increase in LV tissue collagen density (2.62±0.17 and 4.03±0.13%, respectively) without an alteration in LV weight (1.27±0.02 to 1.22±0.03 g; respectively) Short- and long-term treatment with PXL770 improved LV diastolic function in treated ZSF-1, illustrated by the reduced LV EDP (5.34±0.93 and 5.98±0.94 mmHg, short- and long-term PXL770, respectively) and the reduced LV EDPVR (3.31±0.43 and 2.73±0.16 mmHg/RVU, respectively; p<0.05 vs untreated ZSF-1). Simultaneously LV FS was significantly increased (52±1 and 50±1%, respectively; p<0.05 vs untreated ZSF-1), as well as LV ESPVR (34.6±1.4 and 33.0±0.9 mmHg/RVU, respectively; p<0.05 vs untreated ZSF-1). The improvement of diastolic function was associated with a reduction in LV weight (1.19±0.04 and 1.17±0.02 g, respectively; long-term PXL770 p<0.0.5 vs untreated ZSF-1) and a significant reduction in collagen density after long-term PXL770 (3.35±0.12%; p<0.05) but not short-term PXL770 (4.22±0.30%). Conclusion These results suggest that PXL770 exerts protective effects on cardiac function and structure in developing or established cardiomyopathy. Thus, by directly activating AMPK, the PXL770 appears promising for the treatment of cardiac dysfunction associated with metabolic diseases. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Poxel SA

No abstract