The liver is extremely active in oxidizing triglycerides (TG) for energy production. An imbalance between TG synthesis and hydrolysis leads to metabolic disorders in the liver, including excessive lipid accumulation, oxidative stress, and ultimately liver damage. Adipose triglyceride lipase (ATGL) is the rate-limiting enzyme that catalyzes the first step of TG breakdown to glycerol and fatty acids. Although its role in controlling lipid homeostasis has been relatively well-studied in the adipose tissue, heart, and skeletal muscle, it remains largely unknown how and to what extent ATGL is regulated in the liver, responds to stimuli and regulators, and mediates disease progression. Therefore, in this review, we describe the current understanding of the structure–function relationship of ATGL, the molecular mechanisms of ATGL regulation at translational and post-translational levels, and—most importantly—its role in lipid and glucose homeostasis in health and disease with a focus on the liver. Advances in understanding the molecular mechanisms underlying hepatic lipid accumulation are crucial to the development of targeted therapies for treating hepatic metabolic disorders.

Alcohol-related liver disease (ALD) is characterized by accumulation of hepatic free fatty acids (FFAs) and liver injury. The present study aimed to investigate if mechanistic target of rapamycin complex 1 (mTORC1) plays a role in FFA-induced organelle dysfunction, thereby contributing to the development of ALD. Cell studies were conducted to define the causal role and underlying mechanism of FFA-activated mTORC1 signaling in hepatocellular cell injury. C57BL/6J wild-type mice were subjected to chronic alcohol feeding with or without rapamycin to inhibit mTORC1 activation. We revealed that palmitic acid (PA)-induced ER stress and suppression of LAMP2 and autophagy flux were mTORC1-dependent as rapamycin reversed such deleterious effects. C/EBP homologous protein (CHOP) was downstream of ATF4 which partially modulated LAMP2. Supplementation with rapamycin to alcohol-fed mice attenuated mTORC1 activation and ER stress, restored LAMP2 protein, and improved autophagy, leading to amelioration of alcohol-induced liver injury. Induction of mTORC1 signaling and CHOP were also detected in the liver of patients with severe alcoholic hepatitis. This study demonstrates that hepatic FFAs play a crucial role in the pathogenesis of ALD by activating mTORC1 signaling, thereby inducing ER stress and suppressing LAMP2-autophagy flux pathway, which represents an important mechanism of FFA-induced hepatocellular injury.

Background: Dysregulation of bile acids (BAs) has been reported in alcohol-associated liver disease. However, the causal relationship between BA dyshomeostasis and alcohol-associated liver disease remains unclear. The study aimed to determine whether correcting BA perturbation protects against alcohol-associated liver disease and elucidate the underlying mechanism. Methods: BA sequestrant cholestyramine (CTM) was administered to C57BL/6J mice fed alcohol for 8 weeks to assess its protective effect and explore potential BA targets. The causal relationship between identified BA metabolite and cellular damage was examined in hepatocytes, with further manipulation of the detoxifying enzyme cytochrome p450 3A11. The toxicity of the BA metabolite was further validated in mice in an acute study. Results: We found that CTM effectively reversed hepatic BA accumulation, leading to a reversal of alcohol-induced hepatic inflammation, cell death, endoplasmic reticulum stress, and autophagy dysfunction. Specifically, nordeoxycholic acid (NorDCA), a hydrophobic BA metabolite, was identified as predominantly upregulated by alcohol and reduced by CTM. Hepatic cytochrome p450 3A11 expression was in parallel with NorDCA levels, being upregulated by alcohol and reduced by CTM. Moreover, CTM reversed alcohol-induced gut barrier disruption and endotoxin translocation. Mechanistically, NorDCA was implicated in causing endoplasmic reticulum stress, suppressing autophagy flux, and inducing cell injury, and such deleterious effects could be mitigated by cytochrome p450 3A11 overexpression. Acute NorDCA administration in mice significantly induced hepatic inflammation and injury along with disrupting gut barrier integrity, leading to subsequent endotoxemia. Conclusions: Our study demonstrated that CTM treatment effectively reversed alcohol-induced liver injury in mice. The beneficial effects of BA sequestrant involve lowering toxic NorDCA levels. NorDCA not only worsens hepatic endoplasmic reticulum stress and inhibits autophagy but also mediates gut barrier disruption and systemic translocation of pathogen-associated molecular patterns in mice.

Alcohol-associated liver disease (ALD) contributes substantially to the global burden of cirrhosis and liver-related mortality, driven by ethanol metabolism, oxidative stress, and dysregulated immune signaling. Despite rapidly growing evidence implicating interferon regulatory factors (IRFs) in ALD pathogenesis, an integrated framework linking ethanol-induced danger signals to cell-type-specific IRF programs is lacking. In this comprehensive review, we summarize current knowledge on IRF-centered signaling networks in ALD, spanning DAMP–PAMP sensing, post-translational IRF regulation, and downstream inflammatory, metabolic, and fibrogenic outcomes across various cell types in the liver, including hepatocytes and immune-related cells such as Kupffer cells, monocyte-derived macrophages, dendritic cells, T cells, hepatic stellate cells (HSC), and neutrophils. We also focus on how ethanol-driven DAMP and PAMP signals activate TLR4, TLR9, and cGAS–STING pathways to engage a coordinated network of IRFs—including IRF1, IRF3, IRF4, IRF5, IRF7, and IRF9—that collectively shape inflammatory, metabolic, and cell-fate programs across hepatic cell populations. We further highlight emerging therapeutic strategies such as STING/TBK1 inhibition, NETosis blockade, IL-22-based epithelial repair, and JAK-STAT modulation that converge on IRF pathways. In summary, this review outlines how IRFs contribute to ALD pathogenesis and discusses the potential implications for the development of targeted therapies.

The nomenclature for fatty liver diseases, characterized by the accumulation of fat in the liver, has recently been updated by a global consensus of liver organizations and societies for steatotic liver disease (SLD)