SAT-691 - Per-Arnt-Sim Kinase (PASK) Inhibitor Activity Exhibits Differential and Glucose-Dependent Regulation of Hepatic Lipid Accumulation

Per-Arnt-Sim Kinase (PASK) is a nutrient-sensitive serine/threonine protein kinase that regulates glucose and lipid metabolism. However, its role in regulating hepatic lipid accumulation under varying glucose conditions remains unclear. In this study, we examined the effects of PASK inhibition on intracellular lipid accumulation in varying glucose concentrations corresponding to human blood glucose levels: 2.5 mM (45 mg/dL; hypoglycemia), 5.5 mM (100 mg/dL; normal), and 11mM (198 mg/dL; hyperglycemia). A known PASK Inhibitor, BioE-1115, along with two potential novel PASK inhibitors—selected based on predicted enhanced interaction with West African Ancestral PASK variants— were evaluated using cell viability assays of Hep3B hepatocellular carcinoma cells to determine their effect on cell survival and growth. Outcomes of the experiment showed that the novel inhibitors significantly increased cell growth while this trend was not seen in BioE-1115. In addition, the half-maximal inhibitory concentration (IC₅₀) for BioE-1115 was ~35 μM, less than half that of the novel compounds, demonstrating higher cytotoxicity. Hep3B cells were cultured under the varying glucose conditions and treated with 25 μM of each PASK inhibitor. Lipid content was assessed using LipidTOX staining and fluorescence microscopy. Control cells displayed the expected glucose-dependent increase in lipid accumulation in low and high glucose conditions. Under normoglycemic conditions, treatment with the novel inhibitors resulted in greater lipid accumulation compared to BioE-1115. In contrast, under hyperglycemic conditions, the novel inhibitors suppressed lipid accumulation, whereas BioE-1115 showed minimal effect relative to the control. Collectively, these findings suggest that potential novel PASK small-molecule inhibitors differentially regulate hepatic lipid accumulation based on glucose availability. This provides implications for the importance of physiological context in therapeutic targeting of PASK in metabolic disease such as Type 2 Diabetes and Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD).

*Unless otherwise noted, all abstracts presented at ENDO must not be released to the press or the public until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.*