Search Results (3,630)

Background: Long noncoding RNAs (lncRNAs) have emerged as critical regulators of hepatic metabolism and disease progression. The hepatocyte nuclear factor 1 alpha antisense 1 (HNF1A-AS1) lncRNA modulates liver-specific transcription factors; however, its physiological role in diet-dependent lipid homeostasis remains poorly defined. Methods: In this study, we investigated the mouse ortholog, Hnf1a opposite strand 1 (Hnf1aos1), using AAV-mediated knockdown in C57BL/6J mice fed either a chow diet (10% kcal from fat) or a high-fat diet (HFD; 60% kcal from fat) for 12 weeks. Metabolic phenotyping included hepatic lipid quantification, histological analysis, serum biochemistry, and quantitative gene expression profiling. Results: Loss of Hnf1aos1 produced distinct, diet-dependent alterations in hepatic lipid handling. Under chow conditions, knockdown mice exhibited selective hepatic cholesterol accumulation (6.10 ± 2.9 mg/g tissue vs. 3.51 ± 1.1 mg/g in controls), accompanied by dysregulation of cholesterol clearance pathways. In contrast, under HFD conditions, knockdown precipitated severe macrovesicular degeneration, with hepatic triglyceride levels approximately doubled relative to HFD-fed controls (51.72 ± 19.8 mg/g vs. 26.34 ± 11.9 mg/g) and a numerically elevated triglyceride-to-cholesterol ratio (TG:TC ≈ 6.1:1; p = 0.0621, trend). Chow/Kd mice gained significantly less weight than chow-fed controls, whereas HFD/Kd mice exhibited weight gain comparable to HFD controls despite severe hepatic steatosis. This paradoxical phenotype suggests impaired metabolic feedback at the post-transcriptional level, in which compensatory upregulation of Hnf1a mRNA is insufficient to suppress lipid-associated genes such as Cd36, despite profound lipid overload; however, HNF1A protein levels were not directly measured in this study. Conclusion: Collectively, these findings identify Hnf1aos1 as a regulator of hepatic lipid homeostasis whose loss produces a phenotype consistent with inappropriate lipid accumulation during nutrient excess, without defining the underlying molecular mechanism. Our results support a role for Hnf1aos1 in shaping hepatic metabolic plasticity and provide insight into lncRNA-associated MASLD phenotypes. Full article

Background: Research indicates that hepatic gluconeogenesis mediates metabolic coupling between the liver and muscles via the Cori cycle and participates in liver–brain axis communication through its metabolic products and regulatory networks, thereby linking it to the pathogenesis of depression. Together, these mechanisms form the molecular basis for the antidepressant effects of exercise-regulated hepatic gluconeogenesis. Regular exercise promotes skeletal muscle contraction, causing the muscles to release more lactate into the circulatory system. Lactate acts as a substrate for gluconeogenesis and activates downstream signaling pathways, thereby enhancing the gluconeogenic response. During exercise, glycogenolysis directly provides energy, while lactate produced by glycolysis enters the liver via the Cori cycle to serve as a substrate for gluconeogenesis. By maintaining blood glucose homeostasis, this process ensures a stable energy supply to the brain, thereby improving cognitive and emotional functions. This study aims to elucidate how key substrates, regulatory factors, and rate-limiting enzymes involved in hepatic gluconeogenesis and exercise influence brain energy supply, cognitive function, and emotional regulation during depression. It seeks to identify the potential targets and mechanisms through which exercise exerts its antidepressant effects via hepatic gluconeogenesis, with the goal of providing a theoretical foundation for research into the mechanisms of depression and for clinical exercise interventions. Methods: This review conducted a comprehensive search of the recent literature on exercise, hepatic gluconeogenesis, and depression in major domestic and international databases. Adopting an interdisciplinary approach that integrates hepatic gluconeogenesis and exercise, it synthesizes existing evidence to explore the metabolic mechanisms by which exercise improves depression through the regulation of hepatic gluconeogenesis pathways. Results: Research has found that exercise may modulate hepatic gluconeogenic substrates and regulate the expression of cAMP-responsive element-binding protein in states of depression, regulatory factors such as liver kinase B1, forkhead box protein 01, hepatocyte nuclear factor 4 alpha, and peroxisome proliferator activated receptor gamma co activator factor 1 alpha are used to affect key rate limiting enzymes of hepatic gluconeogenesis, such as phosphoenolpyruvate carboxykinase and glucose-6-phosphatase, enhance hepatic gluconeogenesis processes, maintain blood glucose homeostasis, ensure brain energy supply, and improve depression. Conclusions: Exercise intervention targeting hepatic gluconeogenesis may be a potential therapeutic strategy for depression. Full article

The yak (Bos grunniens), a unique bovine species that is endemic to the Qinghai–Tibet Plateau and adjacent mountainous regions, exhibits remarkable adaptations to chronic high-altitude hypoxia. However, the molecular mechanisms underlying yaks’ adaptation to this extreme environment remain poorly understood. This study aimed to elucidate the spatiotemporal expression dynamics of hypoxia-inducible factor 1α (HIF-1α) and 2α (HIF-2α) in major tissues of yaks across developmental stages (0.5, 1.5, 2.5, and 4.5 years; n = 3 per group). The tissues (heart, liver, spleen, lungs, kidneys, blood vessels and skeletal muscles) were analyzed using hematoxylin and eosin (H&E) staining and immunohistochemistry. The results revealed significant differences in the expression levels of HIF-1α and HIF-2α between tissues and at different ages. In cardiac tissue, both HIF-1α and HIF-2α are localized to the myocardial interstitium, with HIF-1α expression peaking at 1.5–2.5 years and HIF-2α expression reaching its maximum at 2.5 years. Hepatic HIF-1α showed perivenous hepatocytes enrichment and peaked at 2.5 years (p < 0.01 vs. other ages), while HIF-2α was uniformly distributed across lobules without age-related changes. Splenic HIF-1α and HIF-2α levels increased progressively with age, both peaking at 4.5 years (p < 0.01), and age was strongly correlated with expression levels (HIF-1α: r = 0.430; HIF-2α: r = 0.493). In pulmonary tissues, HIF-1α in bronchial smooth muscle peaked at 2.5 years, whereas alveolar septal HIF-2α peaked at 1.5 years (p < 0.05). In the kidney, HIF-1α was primarily localized to tubular epithelial cells and HIF-2α was diffusely distributed in the glomerular interstitium; neither factor showed significant variation across ages. In vascular tissues, HIF-1α expression remained stable across all ages and was predominantly observed in the smooth muscle layer, while HIF-2α exhibited a significant peak in endothelial cells at 2.5 years (p < 0.01). These findings suggest that HIF-1α predominates during early development stages, while HIF-2α becomes dominant as yaks approach maturity. Full article

Alcohol-related liver disease (ALD) and ALD-related mortality are associated with hemolysis, increased erythrophagocytosis, and disturbed iron homeostasis. While macrophage-mediated erythrophagocytosis is well established, we investigated the contribution of liver sinusoidal endothelial cells (LSECs) to handling oxidatively damaged or ethanol-primed red blood cells (RBCs) in ALD. Live-cell imaging demonstrated that damaged RBCs were rapidly taken up by SK-HEP1 cells, an endothelial cell line with LSEC-like characteristics, and RBC uptake was associated with induction of heme oxygenase-1 (HO-1) and activation of its upstream regulator Nrf2. siRNA-mediated knockdown of the scavenger receptor Stabilin-1 attenuated RBC-induced HO-1 expression, supporting a role for Stabilin-1 in efferocytic signaling. Exposure of RBCs to ethanol concentrations as low as 25 mM induced phosphatidylserine externalization and rendered erythrocytes efferocytosis-competent. Lysed RBCs and free hemin elicited comparable oxidative stress responses. In murine models of hemolysis and chronic ethanol feeding, hemoglobin-derived signals were detected within sinusoidal structures showing a diffuse CD206-positive distribution pattern consistent with the sinusoidal scavenger compartment. Similar signals were observed in sinusoidal endothelial regions in human heavy drinkers with clinical signs of hemolysis. Together, these data suggest that LSECs may represent an additional component of RBC clearance in ALD, alongside macrophages and hepatocytes, with implications for hepatic iron handling. Full article

Microcystin-LR (MC-LR) is a potent hepatotoxin that has been shown to cause liver damage even at doses lower than the established Low Observable Adverse Effect Level (LOAEL) of 200 μg/kg in animal models. We have previously observed that low-dose exposure to MC-LR in animals with diet-induced Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) and subsequent treatment with antioxidants like N-acetylcysteine (NAC) and the Na⁺/K⁺ ATPase-Src kinase inhibitor pNaKtide significantly alleviated hepatic infiltration of immune cells, downregulated markers of inflammation and hepatotoxicity, increased the breakdown of the toxin molecule, and restored phase I and II drug metabolism pathways, including the glutathione pathway. Because the liver is composed of heterogeneous cell types, this study aimed to determine the specific role of hepatocytes in the uptake and metabolism of MC-LR, especially in the setting of MASLD. To address this, we used two well-established hepatocyte cell lines—AML-12 murine hepatocytes and human Hep3B hepatocytes. Preliminary dose comparison studies with AML-12 cells showed that MC-LR at 10 μM concentration showed a significant upregulation in the genetic expression of the markers of hepatotoxicity—OSMR (p ≤ 0.01) and SerpinE (p ≤ 0.0001)—in comparison to Vehicle. Treatment with pNaKtide (1 µM) and/or NAC (10 mM) in the presence of MC-LR significantly reduced the expression of both OSMR (p ≤ 0.0001) and SerpinE (p ≤ 0.01 and p ≤ 0.0001, respectively). To model steatotic hepatocytes characteristic of the MASLD phenotype, Hep3B hepatocytes were first treated with 500 µM of oleic acid (OA) before exposing them to the toxin in the presence and absence of antioxidants. MC-LR exposure, induced markers of inflammation and hepatotoxicity to be elevated significantly in the presence of OA as compared to MC-LR exposure alone. This elevation of the genetic markers of inflammation and hepatotoxicity was significantly attenuated on treatment with pNaKtide (1 µM) and NAC (10 mM). Quantification of human SERPINE1 (PAI1) and 8-OHdG, a stable marker of oxidative stress, in the spent media of Hep3B cells corroborated the trends observed in the genetic markers of hepatotoxicity. These observations support the central role that hepatocytes play in the uptake and metabolism of MC-LR, which is complicated by the presence of MASLD-like conditions and can help in the development of future therapeutic strategies. Full article

Background/Objectives: Glucagon-like peptide-1 (GLP-1) is a nutritionally regulated incretin involved in the coordination of intestinal, hepatic, and adipose metabolic responses. Although plant-derived extracts are increasingly investigated for their metabolic effects, mechanistic evidence integrating multiple metabolic tissues remains limited. This study aimed to investigate the molecular effects of a combination of plant-derived extracts in an integrated in vitro gut–liver–adipose model. Methods: Differentiated Caco-2 monolayers were exposed to a standardised combination of plant-derived extracts obtained from Gastrodia elata, Morus alba, and Paeonia lactiflora. GLP-1 secretion and epithelial barrier integrity were assessed. Conditioned media from intestinal cells were applied to HepG2 hepatocytes, and downstream effects on lipid metabolism-related pathways were evaluated. Subsequently, conditioned media from hepatic cells were applied to differentiated 3T3-L1 adipocytes to assess lipid accumulation and metabolic signalling. Results: Exposure of intestinal cells to the extract combination significantly increased GLP-1 secretion without altering epithelial barrier integrity. Intestinal conditioned media were associated with reductions in intracellular triglyceride levels in hepatocytes and with modulation of markers linked to lipid handling, including resistin, FGF21, SREBP-1c, NRF2, Src, AMPK, SIRT1, and PGC1α, suggesting GLP-1-associated effects. In adipocytes, hepatic conditioned media decreased lipid accumulation and increased the levels of metabolic markers associated with adipocyte browning-related signalling, including UCP1, NOS, SIRT1, and STAT3. Conclusions: Within the limitations of this in vitro multi-organ model, these findings suggest that the tested combination of plant-derived extracts modulates cellular pathways related to GLP-1-associated metabolic signalling across intestinal, hepatic, and adipose systems. These results should be interpreted as mechanistic and hypothesis-generating, and further in vivo and clinical studies are required to confirm their physiological relevance. Full article

Hepatocellular carcinoma (HCC) is the most common type of liver cancer that is mostly preceded by cirrhosis, with a high mortality rate. Therefore, diagnosis is critical in the early stages. In this study, we explored the liver expression of metabotropic glutamate receptor 3 (mGluR3), a group II mGluR, during the progression from fibrosis to cirrhosis and, ultimately, to HCC induced by diethylnitrosamine (DEN) in rats. We found that mRNA expression of mGluR3 (Grm3) was upregulated in HCC, while the protein level was significantly increased from the cirrhosis stage, and even more in HCC. Grm3 correlated with interleukin-6 (Il6) and transforming growth factor-β (Tgfb) mRNA expression. Furthermore, serum and intrahepatic glutamate concentrations were augmented in HCC. Immunohistochemical analysis revealed that mGluR3 is expressed in hepatocytes and non-parenchymal cells (endothelial cells and macrophages), and we observed a positive signal in the cytoplasmic membrane, cytoplasm, and nuclei of tumor and non-tumor cells. We confirmed that normal hepatocytes (C9 cell line) express low levels of mGluR3 protein and HCC-derived cells (HepG2) express high levels of this receptor. Using HepG2 cells, we observed that mGluR3 activation by glutamate and the group II-selective agonist LY354740 treatments were functional, as both inhibited cAMP generation induced by forskolin and increased cellular viability with no effect on dead cells. These results showed that mGluR3 is differentially expressed throughout the progression of liver pathologies, is associated with the inflammatory environment, and plays a role in HCC cell survival, with potential utility as an early biomarker and therapeutic target. Full article

Although ombitasvir/paritaprevir/ritonavir plus dasabuvir (OPrD) therapy is highly effective for chronic hepatitis C (CHC), clinicians frequently encounter transient hyperbilirubinemia, which can be misidentified as hepatotoxicity. This study investigated the role of SLCO1B1 (OATP1B1) and SLCO1B3 (OATP1B3) genetic polymorphisms in predicting bilirubin spikes and distinguishing transporter-mediated interference from hepatocellular injury. In this prospective study of 65 patients with HCV genotype 1, genotyping for OATP1B1 (c.388A>G, c.521T>C) and OATP1B3 (c.334T>G, c.699G>A) was performed using PCR-RFLP and capillary electrophoresis (QIAxcel Advanced System). Clinical and biochemical parameters were monitored over a 12-week treatment period. Hyperbilirubinemia (total bilirubin >1.1 mg/dL) developed in 18.5% of the cohort, typically within the first month. A distinct ‘AST-dominant’ biochemical signature, elevated bilirubin and AST paired with stable ALT, was identified, suggesting transporter-specific interference rather than hepatocyte damage. Statistical analysis pinpointed the OATP1B3 c.699G>A (rs7311358) variant as the sole genetic driver (p = 0.007). Carriers of the c.699G>A allele faced a 6.3-fold higher risk of developing hyperbilirubinemia (OR: 6.30, 95% CI: 1.48–26.80, p = 0.032), while no significant associations were found for OATP1B1 variants. We conclude that OATP1B3 c.699G>A is a potent predictor of OPrD-induced hyperbilirubinemia. Identifying this genotype pre-treatment allows clinicians to anticipate transient, benign bilirubin elevations and prevent unnecessary drug discontinuation, thereby mitigating therapeutic inertia and ensuring treatment continuity for CHC patients. Full article

Steatosis, characterized by excessive fat accumulation in the liver, is a significant precursor to chronic liver disease and hepatocarcinoma. This condition is influenced by multiple contributing factors such as obesity, alcohol consumption, and exposure to chemicals or drugs. Systems biology approaches including transcriptomics and metabolomics can aid in grouping chemicals according to their mode of action. In this study, we analyze transcriptomic and metabolomic data from primary human and transformed hepatocytes, respectively, to differentiate between steatotic and non-steatotic chemicals. Rather than assessing each steatotic compound individually, we pooled several steatotic chemicals in order to minimize compound-specific noise and better identify features associated with the underlying process of steatosis. Differential gene expression analysis revealed established mechanisms involved in steatosis, consistent with the recently updated adverse outcome pathway. Likewise, metabolomic data enabled clear discrimination between steatotic and non-steatotic chemicals. These findings highlight the potential of omics technologies to support chemical grouping based on insights into the molecular mechanisms that drive steatosis development. Full article

Intestinal dysfunction and parenteral nutrition (PN) can trigger a spectrum of liver disorders collectively referred to as intestinal failure-associated liver disease (IFALD), for which therapeutic options remain limited. In the present study, we investigated the modulatory effects of the bioactive xanthophyll carotenoid lutein in an in vitro IFALD model utilizing human THLE-2 hepatocytes exposed to lipopolysaccharide and Intralipid to mimic PN–associated inflammatory and metabolic stress. Because lutein is poorly water-soluble and patients receiving PN lack enteral intake of this compound, we also evaluated the cyto- and hemocompatibility of a human serum albumin–based lutein nanoformulation developed to enable intravenous administration. A bead-based multiplex immunoassay revealed that lutein attenuated dysregulation of inflammatory and metabolic signaling by modulating total and phosphorylated levels of MAPKs, NF-κB, Akt, STAT5, CREB, and p70S6K. Lutein also affected lipid metabolism–related gene expression, decreasing SREBF2 and restoring ABCA1 and PRKAA2 mRNA toward control levels, as determined by qPCR. Nanoformulated lutein, with a mean particle size of approximately 160 nm, was non-toxic in THLE-2 cells and exhibited hemocompatibility in a human erythrocyte hemolysis assay. Together, our findings provide both biological and technological rationale for further exploration of lutein-based strategies to mitigate IFALD in patients receiving PN. Full article

Arginase 1 (ARG1) deficiency (ARG1-D) is a rare genetic disorder due to loss of ARG1, the final enzyme in the urea cycle. ARG1-D hepatocytes are impaired in converting arginine into urea, resulting in elevated peripheral arginine and ammonia, which leads to progressive neurological symptoms. Current therapeutic strategies mainly focus on managing plasma arginine and ammonia level, but long-term outcomes remain poor. While no approved treatment specific for ARG1-D is available in the United States, a recombinant protein-based enzyme replacement therapy is available in Europe. Recently, extracellular vesicles (EVs) are emerging as a powerful therapeutic vehicle. By using Capricor’s StealthX^TM platform, EVs were engineered to express human ARG1 on their surface or encapsulated within. Regardless of their localization on the EV membrane, nanograms of ARG1 carried by EVs were biologically active and able to convert arginine into urea as potent as micrograms of human recombinant ARG1 (rHuArg1). Furthermore, ARG1-encapsulating EVs (STX-Arg1-in) were able to deliver ARG1 intracellularly but not EVs carrying ARG1 on their surface or rHuArg1. STX-Arg1-in EVs were further evaluated in a series of in vivo studies, and the results showed that STX-Arg1-in EVs were non-toxic and able to restore arginase activities in the liver of Arg1^−/− mice, which led to a lowered plasma arginine concentration similar to that in wild-type mice. Most importantly, Arg1-in EVs expanded the lifespan of the lethal neonatal Arg1 deficiency mouse model. Taken together, our data suggested StealthX^TM-engineered STX-Arg1-in EVs have a better safety profile due to the extremely low dosage and have great potential as a novel enzyme replacement strategy for patients suffering from ARG1-D. Significance statement: Intracellular delivery of recombinant protein and improved llifespanare endpoints of successful enzyme replacement therapy for the treatment of ARG1-D. Using the StealthX platform, a fully functional ARG1 enzyme was engineered to be carried inside of the extracellular vesicles, which allowed for the intracellular delivery of ARG1 protein in vitro and in vivo, with an improvement of lifespan in a lethal neonatal mouse model of Arg1 deficiency. More importantly, no toxicity was observed, and efficacy was achieved with a low dose, setting the base for an improved therapeutic approach. Full article

The sodium-taurocholate cotransporting polypeptide (NTCP) plays a critical dual role in liver function: maintaining bile acid (BA) enterohepatic circulation and acting as a receptor for the entry of hepatitis B and D viruses into hepatocytes. This review outlines the impact of various post-translational modifications (PTMs) of NTCP—including phosphorylation, oligomerization, ubiquitination, and glycosylation—on its dynamic regulatory network. These modifications coordinate the modulation of NTCP’s membrane localization, stability, conformational state, and protein interactions, precisely controlling its functions in BA uptake and viral invasion. Targeting this PTM network presents a promising strategy for next-generation therapies that selectively inhibit viral infection while preserving BA transport, overcoming the limitations of conventional inhibitors that indiscriminately disrupt virus–NTCP interactions. By synthesizing recent insights into NTCP PTM research, this article highlights its role as a central regulator of its bifunctional properties and reveals potential avenues for precision therapies in viral hepatitis, cholestasis, and related liver diseases. However, most existing evidence is derived from in vitro or cell-based models, whereas in vivo studies and clinical validation remain limited; thus, the translational feasibility of strategies targeting post-translational modifications of NTCP still requires further investigation. Full article

RNA degradation plays a vital role in post-transcriptional regulation of gene expression. RNA stability is changed in the pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD), but its role and underlying mechanisms in sleeve gastrectomy (SG) effectively remodeling hepatocytes and improving MASLD is unclear. A high-fat diet-induced MASLD model for SG and a hepatocyte-specific Zfp36 knockdown mouse model were established to evaluate the role of zinc finger protein 36 (ZFP36) in MASLD. The expression of ZFP36 and TEA domain transcription factor 4 (TEAD4) was examined in liver tissue samples from MASLD patients. Hepatic ZFP36 expression is downregulated in MASLD but is restored following SG. Hepatocyte-specific Zfp36 knockdown exacerbates high-fat diet-induced liver injury and impairs the therapeutic effect of SG on hepatic steatosis. Mechanistically, ZFP36 binds to TEAD4 mRNA to promote its degradation, thereby modulating the Hippo pathway. Inhibition of TEAD4 transcriptional activity reverses the aggravated MASLD phenotype caused by Zfp36 knockdown. In liver biopsy samples from MASLD patients, ZFP36 expression correlates negatively with TEAD4 expression. Collectively, these findings identify SG-induced upregulation of ZFP36 as a critical mechanism for alleviating MASLD through suppression of TEAD4. Full article

Tor sinensis is an emerging aquaculture species in China, yet the effect of dietary protein on its hepatic and intestinal health remains unexplored. This study evaluated the effects of five diets designed to be isoenergetic and isolipidic with graded protein levels (28% to 40%) on juvenile T. sinensis (initial weight: 10 ± 0.4 g) over 60 days. Growth performance improved with increasing protein up to 34%, beyond which it plateaued. Regression analysis indicates that the optimal dietary protein level for both weight gain and specific growth rate is 34.3%. Hepatic antioxidant enzyme activities (SOD and CAT) were highest in the 34% protein group, while triglyceride content was lowest. Histological examination revealed minimal hepatocyte swelling, nuclear displacement, and lipid droplet accumulation at this protein level. Intestinal trypsin activity and villus morphology (height, width, and muscular thickness) were also optimized at 34% protein, though lipase and amylase activities remained unaffected. These findings demonstrate that a 34% dietary protein level supports optimal growth, enhances liver antioxidant capacity, and improves intestinal structure and function in juvenile T. sinensis, providing critical insights for its formulated feed development. Full article

This study aimed to investigate whether mixed heavy metal exposure (lead, cadmium, manganese, and arsenic) during pregnancy induces gestational diabetes mellitus (GDM)-like phenotypes and to explore the associated molecular alterations. We examined the effects of exposure on metabolic disturbances using a Sprague-Dawley rat model exposed to low- and high-dose mixed heavy metals, with doses selected based on biomonitoring data. The results showed that high-dose mixed heavy metal exposure significantly increased blood glucose levels in rats, elevated the area under the curve (AUC) during the oral glucose tolerance test (OGTT), and induced insulin resistance and dyslipidemia. Concurrently, pathological examinations revealed hepatocyte steatosis, inflammatory cell infiltration, and mitochondrial abnormalities in liver tissues. Transcriptomic and metabolomic analyses identified significant disruption of the glycerophospholipid metabolic pathway following heavy metal exposure, suggesting the involvement of this pathway in the observed metabolic disturbances. Lasso regression analysis identified Insig1 as a candidate gene associated with lipid metabolic alterations, a finding subsequently validated by qPCR. Overall, mixed heavy metal exposure during pregnancy was associated with GDM-like metabolic abnormalities in rats. Disruption of glycerophospholipid metabolism and altered Insig1 expression likely contribute to these effects, providing molecular evidence linking mixed heavy metal exposure to gestational metabolic dysfunction. Full article