TSA attenuates the progression of c-Myc-driven hepatocarcinogenesis by pAKT-ADH4 pathway.

Hepatocellular carcinoma (HCC) is the primary malignant tumor of the liver. c-Myc is one of the most common oncogenes in clinical settings, and amplified levels of c-Myc are frequently found in HCC. Histone deacetylase inhibitors (HDACi), such as Trichostatin A (TSA), hold enormous promise for the treatment of HCC. However, the potential and mechanism of TSA in the treatment of c-Myc-induced HCC are unclear. In this study, we investigated the effects of TSA treatment on a c-Myc-induced HCC model in mice. TSA treatment delayed the development of HCC, and liver function indicators such as ALT, AST, liver weight ratio, and spleen weight ratio demonstrated the effectiveness of TSA treatment. Oil red staining further demonstrated that TSA attenuated lipid accumulation in the HCC tissues of mice. Through mRNA sequencing, we identified that TSA mainly affected cell cycle and fatty acid degradation genes, with alcohol dehydrogenase 4 (ADH4) potentially being the core molecular downstream target. QPCR, immunohistochemistry, and western blot analysis revealed that ADH4 expression was repressed by c-Myc and restored after TSA treatment both in vitro and in vivo. Furthermore, we observed that the levels of total NAD+ and NADH, NAD+, NAD+/NADH, and ATP concentration increased after c-Myc transfection in liver cells but decreased after TSA intervention. The levels of phosphorylated protein kinase B (p-AKT) and p-mTOR were identified as targets regulated by TSA, and they governed the ADH4 expression and the downstream regulation of total NAD+ and NADH, NAD+, NAD+/NADH, and ATP concentration. Overall, our study suggests that TSA has a therapeutic effect on c-Myc-induced HCC through the AKT-mTOR-ADH4 pathway. These findings provide valuable insights into the potential treatment of HCC using TSA and shed light on the underlying molecular mechanisms involved.

Cyclic adenosine 3', 5'-monophosphate (cAMP) signaling is a crucial therapeutic target for ulcerative colitis.

The pathogenesis of ulcerative colitis (UC), a chronic intestine inflammatory disease primarily affecting adolescents, remains uncertain. Contemporary studies suggest that a confluence of elements, including genetic predispositions, environmental catalysts, dysregulated immune responses, and disturbances in the gut microbiome, are instrumental in the initiation and advancement of UC. Among them, inflammatory activation and mucosal barrier damage caused by abnormal immune regulation are essential links in the development of UC. The impairment of the mucosal barrier is intricately linked to the interplay of various cellular mechanisms, including oxidative stress, autophagy, and programmed cell death. An extensive corpus of research has elucidated that level of cyclic adenosine 3',5'-monophosphate (cAMP) undergo modifications in the midst of inflammation and participate in a diverse array of cellular operations that mitigate inflammation and the impairment of the mucosal barrier. Consequently, a plethora of pharmacological agents are currently under development, with some advancing through clinical trials, and are anticipated to garner approval as novel therapeutics. In summary, cAMP exerts a crucial influence on the onset and progression of UC, with fluctuations in its activity being intimately associated with the severity of the disease's manifestation. Significantly, this review unveils the paramount role of cAMP in the advancement of UC, offering a tactical approach for the clinical management of individuals afflicted with UC.

Morroniside delays the progression of non-alcoholic steatohepatitis by promoting AMPK-mediated lipophagy.

BACKGROUND: Non-alcoholic steatohepatitis (NASH), the inflammatory subtype in the progression of non-alcoholic fatty liver disease, is becoming a serious burden threatening human health, but no approved medication is available to date. Mononoside is a natural active substance derived from Cornus officinalis and has been confirmed to have great potential in regulating lipid metabolism in our previous studies. However, its effect and mechanism to inhibit the progression of NASH remains unclear. PURPOSE: Our work aimed to explore the action of mononoside in delaying the progression of NASH and its regulatory mechanisms from the perspective of regulating lipophagy. METHODS AND RESULTS: Male C57BL/6 mice were fed with a high-fat and high-fructose diet for 16 weeks to establish a NASH mouse model. After 8 weeks of high-fat and high-fructose feeding, these mice were administrated with different doses of morroniside. H&E staining, ORO staining, Masson staining, RNA-seq, immunoblotting, and immunofluorescence were performed to determine the effects and molecular mechanisms of morroniside in delaying the progression of NASH. In this study, we found that morroniside is effective in attenuating hepatic lipid metabolism disorders and inflammatory response activation, thereby limiting the progression from simple fatty liver to NASH in high-fat and high-fructose diet-fed mice. Mechanistically, we identified AMPK signaling as the key molecular pathway for the positive efficacy of morroniside by transcriptome sequencing. Our results revealed that morroniside maintained hepatic lipid metabolism homeostasis and inhibited NLRP3 inflammasome activation by promoting AMPKα phosphorylation-mediated lipophagy and fatty acid oxidation. Consistent results were observed in palmitic acid-treated cell models. Of particular note, silencing AMPKα both in vivo and in vitro reversed morroniside-induced lipophagy flux enhancement and NLRP3 inflammasome inhibition, emphasizing the critical role of AMPKα activation in the effect of morroniside in inhibiting NASH progression. CONCLUSION: In summary, the present study provides strong evidence for the first time that morroniside inhibits NASH progression by promoting AMPK-dependent lipophagy and inhibiting NLRP3 inflammasome activation, suggesting that morroniside is expected to be a potential molecular entity for the development of therapeutic drugs for NASH.

Integration of network pharmacology, lipidomics, and transcriptomics analysis to reveal the mechanisms underlying the amelioration of AKT-induced nonalcoholic fatty liver disease by total flavonoids in vine tea.

Nonalcoholic fatty liver disease (NAFLD) is the main reason for chronic liver diseases and malignancies. Currently, there is a lack of approved drugs for the prevention or treatment of NAFLD. Vine tea (Ampelopsis grossedentata) has been used as a traditional Chinese beverage for centuries. Vine tea carries out several biological activities including the regulation of plasma lipids and blood glucose, hepato-protective function, and anti-tumor activity and contains the highest content of flavonoids. However, the underlying mechanisms of total flavonoids from vine tea (TF) in the attenuation of NAFLD remain unclear. Therefore, we investigated the interventions and mechanisms of TF in mice with NAFLD using an integrated analysis of network pharmacology, lipidomics, and transcriptomics. Staining and biochemical tests revealed a significant increase in AKT-overexpression-induced (abbreviated as AKT-induced) NAFLD in mice. Lipid accumulation in hepatic intracellular vacuoles was alleviated after TF treatment. In addition, TF reduced the hepatic and serum triglyceride levels in mice with AKT-induced NAFLD. Lipidomics results showed 32 differential lipids in the liver, mainly including triglycerides (TG), diglycerides (DG), phosphatidylcholine (PC), and phosphatidylethanolamine (PE). Transcriptomic analysis revealed that 314 differentially expressed genes were commonly upregulated in the AKT group and downregulated in the TF group. The differential regulation of lipids by the genes Pparg, Scd1, Chpt1, Dgkz, and Pla2g12b was further revealed by network enrichment analysis and confirmed by RT-qPCR. Furthermore, we used immunohistochemistry (IHC) to detect changes in the protein levels of the key proteins PPARγ and SCD1. In summary, TF can improve hepatic steatosis by targeting the PPAR signaling pathway, thereby reducing de novo fatty acid synthesis and modulating the glycerophospholipid metabolism.

Vine tea total flavonoids activate the AMPK/mTOR pathway to amelioration hepatic steatosis in mice fed a high-fat diet.

Vine tea (Ampelopsis grossedentata), a traditional Chinese tea, is rich in flavonoids with various biological activities. Our study found that Vine tea total flavonoids (TFs) treatment reduced the body mass and blood lipid levels and improved the hepatic tissue morphology in mice fed the high-fat diet (HFD). In vivo, TF treatment activated the hepatic adenosine monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway, initiated autophagy, and regulated the expression levels of proteins for lipid metabolism in those HFD-fed mice. In vitro, TF treatment dramatically reduced the lipid droplets and triacylglycerol content in HepG2 and L02 cells treated with oleic acid (OA). These were associated with the activation of the AMPK/mTOR pathway and autophagy initiation in OA-treated hepatocytes. This phenotype was abolished in the presence of 3-methyladenine, an autophagy inhibitor. Our results indicated that the TF activation of AMPK/mTOR leads to the stimulation of autophagy and a decrease in the buildup of intracellular lipids in hepatocytes, showing the potential of TF as a therapeutic agent for nonalcoholic fatty liver disease. PRACTICAL APPLICATION: Vine tea, a tea drink, has been consumed by Chinese folk for over a thousand years. The result of this study will provide evidence that vine tea total flavonoids have potential use as a functional material for the prevention and amelioration of nonalcoholic fatty liver disease.

Liver-derived Exosomal miRNA in NAFLD: Mechanisms of Action, Biomarkers, and Therapeutic Applications.

Nonalcoholic fatty liver disease (NAFLD) is of global concern due to its high prevalence worldwide. NAFLD, as one of the most common causes of liver function abnormalities, is associated with obesity, insulin resistance, and type 2 diabetes mellitus, and there are no medications available to treat NAFLD. Extracellular vesicles (EVs) are nanosized, membrane-bound vesicles that deliver biomolecules between cells. Exosomes are a subtype of EVs that mediate intercellular communication by delivering proteins and RNAs. MicroRNAs (miRNAs) are a highly conserved class of small tissue-specific non-coding RNAs that influence the expression of many functionally interacting genes. Hepatic-derived exosomal miRNAs are tightly associated with NAFLD occurrence and progression through multiple mechanisms. In addition, the characterization of miRNAs suggests that they may serve as multifunctional biomarkers for NAFLD, be used as clinical therapeutic targets for NAFLD, and be significant predictors of patient prognosis. Here, we review recent advances in the regulation and function of exosome-derived miRNAs in NAFLD, focusing on miRNAs specifically expressed or enriched in hepatocytes (HCs), hepatic macrophages, hepatic stellate cells (HSCs), and other immune cells in the liver. Finally, we discuss future research directions on exosomal miRNAs as biomarkers for NAFLD's diagnosis and clinical therapeutic targets.

Selenium Nanoparticles Stabilized by ß-Glucan Nanotubes from Black Fungus and Their Effects on the Proliferation, Apoptosis, and Cell Cycle of HepG2 Cells.

Selenium nanoparticles (Se NPs) have significant anticancer effects, but their poor water solubility and dispersibility limit their further applications in biomedical fields. Biomacromolecules have often been used as dispersants or stabilizers in synthesized Se NPs because they can enhance the dispersibility of Se NPs and reduce their side effects. Our previous studies reported a triple-helix ß-glucan (BFP) from the fruiting bodies of black fungus, which showed a good self-assembly ability in constructing hollow nanotubes for loading metal nanoparticles. Therefore, in the present work, BFP nanotubes were designed as carriers to entrap large amounts of Se NPs in order to enhance their stability and anticancer effects. The results showed that Se NPs were successfully synthesized and loaded inside the BFP nanotubes, and the composite (BFP-Se) exhibited high stability and dispersibility due to the covalent Se-O bonds between the Se NPs and the hydroxyl groups on the BFP nanotubes. Moreover, BFP-Se showed significant effects on the proliferation, apoptosis, and cell cycle of HepG2 cells compared to those exhibited by Se NPs. The mechanism was associated with BFP, which acted as a dispersant or stabilizer, resulting in the enhanced cellular uptake of the Se NPs. BFP also activated the death receptor-mediated and mitochondria-mediated apoptotic pathways in HepG2 cells. These results suggest that BFP-Se has potential applications in biomedical fields, especially for the treatment of human liver cancers.

The extraction, structure characterization and hydrogel construction of a water-insoluble ß-glucan from Poria cocos.

Most reported polysaccharides from Poria cocos (PCPs) in traditional Chinese medicine decoctions were water-soluble heteropolysaccharides while the water-insoluble PCPs were scarcely researched due to the poor water-solubility. In this study, a water-insoluble polysaccharide with high yield of 59%, and high purity with a glucan content of 98.8%, was isolated by diluted sodium hydroxide at low temperature and coded as PCPA. The chemical structure of PCPA was identified as a liner ß-glucan with 1, 3-linked glycosidic bond by the fourier infrared spectrum (FT-IR), ion chromatography (ICP), gas chromatography and mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) measurements. Importantly, PCPA was successfully used to construct hydrogels (PCPA-Gs) with good thermal stability, water retention ability and swelling property through simple physical cross-linking, due to the abundance of hydroxyl groups on glucan chains. Moreover, the rheology analysis of PCPA-Gs showed a rapid transition between gel and sol as well as the shear-thinning property. The hydrogel developed in this study holds promise for applications in the food, pharmaceutical, and cosmetic fields.

Quercetin ameliorates nonalcoholic fatty liver disease (NAFLD) via the promotion of AMPK-mediated hepatic mitophagy.

The global incidence of nonalcoholic fatty liver disease (NAFLD) has been surging in recent years, however, no drug is currently approved to treat this disease. Quercetin, a natural flavonoid abundant in plants and fruits, has been reported to alleviate NAFLD, however, the exact molecular mechanism remains unclear. This study aims to further elucidate its potential mechanism of action. The beneficial effects and the underlying mechanism of quercetin in alleviating NAFLD were explored both in vitro and in vivo, by employing chemical inhibitors of autophagosomes (3-methyladenine, 3-MA), autolysosomes (chloroquine, CQ), AMPK (Compound C, CC) and SIRT1 (selisistat, EX-527). The levels of intracellular lipids, reactive oxygen species, mitochondria function, autophagy, and mitophagy were assessed by fluorescent labeling and examined using flow cytometry or confocal microscopy. Key protein expressions of autophagy, mitophagy, and inflammation were also determined. In vivo, quercetin was shown to dose-dependently effectively alleviate NAFLD, but intraperitoneal injection of 3-MA could block the beneficial effects of quercetin on body weight, liver weight, serum ALT/AST, hepatic ROS and inflammation. In vitro, quercetin could reduce intracellular lipids (Nile Red staining) and ROS/DHE accumulation, which could be also blocked by 3-MA or CQ. Furthermore, we found that CC could abrogate the protective effects of quercetin on lipid and ROS accumulation in vitro. Also, CC abolished the proautophagic and anti-inflammatory effects of quercetin, as shown by western blot determination and Lyso-Tracker labeling. Importantly, mitophagy, a specific form of mitochondria-targeted autophagy, was enhanced by quercetin, as demonstrated by PINK1/Parkin protein variation and immunofluorescence colocalization of autophagosomes and mitochondria, which could also be blocked by the intervention of CC. This study demonstrates that quercetin prevents NAFLD through AMPK-mediated mitophagy and suggests that promoting mitophagy via an upregulation of AMPK may be a promising therapeutic strategy against NAFLD.

Specific discrimination of zinc and manganese ions by label free dual emissive carbon dots by ratio-metric mode.

Due to the worldwide ecological and environmental issues induced by heavy metal pollution, including zinc and manganese, the ratio-metric discrimination of Zn2+ and Mn2+ based on CDs is urgently required. In this work, reduced CDs (re-CDs) with the intrinsic dual emissive peaks are obtained, and specific discrimination of Zn2+ and Mn2+ is realized by re-CDs with ratio-metric mode. With the addition of Zn2+, the fluorescent (FL) intensity at 650 nm increases obviously, while that at 680 nm progressively decreases. However, the presence of Mn2+ would induce the quenching of FL intensity at 680 nm while that at 650 nm remains constant. Then the Zn2+ and Mn2+ can be separately determined with the ratio of FL intensity at 650 nm to that at 680 mm (F650/F680). Under optimal conditions, the limit of detection (LOD) of Zn2+ is determined to be 9.09 nmol/L, and that for Mn2+ is estimated to be 0.93 nmol/L, which is much lower than previously reported work and standard level of Zn2+ and Mn2+ permitted in drinking water by WHO. Moreover, the specific recognition of Mn2+ and Zn2+ can be realized via the addition of different masking agents (ethylenediamine for Zn2+ and triethanolamine for Mn2+). Furthermore, our results reveal that the structural changes from -NH-CO to -NC-OH induced by Zn2+ contribute to the shift of FL peak from 680 to 650 nm while both static and dynamic quenching processes are involved in the detection of Mn2+. The ratio-metric probe was successfully applied to Zn2+ and Mn2+ determination in human serum samples and Sandy Lake water.

Ferroptosis as an emerging therapeutic target in liver diseases.

Ferroptosis is an iron-dependently nonapoptotic cell death characterized by excessive accumulation of lipid peroxides and cellular iron metabolism disturbances. Impaired iron homeostasis and dysregulation of metabolic pathways are contributors to ferroptosis. As a major metabolic hub, the liver synthesizes and transports plasma proteins and endogenous fatty acids. Also, it acts as the primary location of iron storage for hepcidin generation and secretion. To date, although the intricate correlation between ferroptosis and liver disorders needs to be better defined, there is no doubt that ferroptosis participates in the pathogenesis of liver diseases. Accordingly, pharmacological induction and inhibition of ferroptosis show significant potential for the treatment of hepatic disorders involved in lipid peroxidation. In this review, we outline the prominent features, molecular mechanisms, and modulatory networks of ferroptosis and its physiopathologic functions in the progression of liver diseases. Further, this review summarizes the underlying mechanisms by which ferroptosis inducers and inhibitors ameliorate liver diseases. It is noteworthy that natural active ingredients show efficacy in preclinical liver disease models by regulating ferroptosis. Finally, we analyze crucial concepts and urgent issues concerning ferroptosis as a novel therapeutic target in the diagnosis and therapy of liver diseases.

The essential effect of mTORC1-dependent lipophagy in non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is a chronic progressive liver disease with increasing prevalence. Lipophagy is a type of programmed cell death that plays an essential role in maintaining the body's balance of fatty acid metabolism. However, the livers of NAFLD patients are abnormally dysregulated in lipophagy. mTORC1 is a critical negative regulator of lipophagy, which has been confirmed to participate in the process of lipophagy through various complex mechanisms. Therefore, targeting mTORC1 to restore failed autophagy may be an effective therapeutic strategy for NAFLD. This article reviews the main pathways through which mTORC1 participates in the formation of lipophagy and the intervention effect of mTORC1-regulated lipophagy in NAFLD, providing new therapeutic strategies for the prevention and treatment of NAFLD in the future.

Ellagitannins-Derived Intestinal Microbial Metabolite Urolithin A Ameliorates Fructose-Driven Hepatosteatosis by Suppressing Hepatic Lipid Metabolic Reprogramming and Inducing Lipophagy.

Excessive fructose consumption exacerbates the progression of nonalcoholic fatty liver disease (NAFLD) by disrupting hepatic lipid homeostasis. This study sought to evaluate the efficacy of urolithin A (UroA) in a fructose-induced NAFLD mouse model. UroA was administered in the high-fructose-fed mice to investigate the antisteatotic effects in vivo. Fructose-stimulated HepG2 cells and primary hepatocytes were established for in vitro mechanistic assessment. The results suggested that UroA ameliorated fructose-induced hepatic steatosis in mice. Mechanistically, UroA impaired lipogenesis and enhanced ß-oxidation in the livers of fructose-fed mice. Notably, UroA facilitated hepatic lipophagy through the AMPK/ULK1 pathway both in vivo and in vitro, degrading lipid droplets for fueling ß-oxidation. This study indicates that UroA alleviates excessive lipid accumulation and restores lipid homeostasis in the livers of fructose-fed mice by suppressing lipid metabolic reprogramming and triggering lipophagy. Therefore, dietary supplementation of UroA or ellagitannins-rich foods may be beneficial for NAFLD individuals with high fructose intake.

Triptolide inhibits intrahepatic cholangiocarcinoma growth by suppressing glycolysis via the AKT/mTOR pathway.

BACKGROUND: High levels of glycolysis supply large quantities of energy and biological macromolecular raw materials for cell proliferation. Triptolide (TP) is a kind of epoxy diterpene lactone extracted from the roots, flowers, leaves, or grains of the Celastraceae plant, Tripterygium wilfordii. TP has multiple biological activities, including anti-inflammatory, immunologic suppression, and anti-cancer effects. Nevertheless, it is little known regarding its anti-intrahepatic cholangiocarcinoma (ICC) growth, and the mechanism still require exploration. PURPOSE: This research explored the effect of TP on ICC growth and investigated whether TP inhibits glycolysis via the AKT/mTOR pathway. METHODS: Cell proliferation was analyzed by Cell Counting Kit-8 (CCK-8), clonogenic assay, and flow cytometry. The underlying molecular mechanism was identified by determining glucose consumption, ATP production, lactate production, hexokinase (HK) and pyruvate kinase (PK) activity, and Western blot analysis. A rapid ICC model of AKT/YapS127A oncogene coactivation in mice was used to clarify the effect of TP treatment on tumor growth and glycolysis. RESULTS: The results showed that TP treatment significantly inhibited ICC cell proliferation and glycolysis in a dose- and time-dependent manner(P < 0.05). Further analysis suggested that TP suppressed ICC cell glycolysis by targeting AKT/mTOR signaling. Additionally, we found that TP inhibits tumor growth and glycolysis in AKT/YapS127A mice(P < 0.05). CONCLUSION: Taken together, we revealed that TP suppressed ICC growth by suppressing glycolysis via the AKT/mTOR pathway and may provide a potential therapeutic target for ICC treatment.

Gallic acid impairs fructose-driven de novo lipogenesis and ameliorates hepatic steatosis via AMPK-dependent suppression of SREBP-1/ACC/FASN cascade.

Accumulating evidence suggests that de novo lipogenesis is a typical characteristic facilitating nonalcoholic fatty liver disease (NAFLD) progression. Gallic acid (GA) is a naturally occurring phenolic acid with metabolic disease-related clinical significance and preclinical benefits. This study aimed to evaluate the anti-steatotic potentials of GA in a fructose-induced NAFLD mouse model featuring a hepatic lipogenic phenotype. The results revealed that GA alleviated hepatic steatosis, oxidative stress, and inflammatory response in fructose-fed mice. Mechanistically, GA treatment restored AMP-activated protein kinase α (AMPKα) phosphorylation, resulting in downregulations of pro-lipogenic factors, including sterol regulatory element binding protein-1 (SREBP-1), fatty acid synthetase (FASN), and acetyl-CoA carboxylase (ACC), in hepatocytes of mice and in vitro. Furthermore, computational docking analysis indicated that GA could directly interact with AMPKα/ß subunits to stabilize its activation. These results suggest that GA ameliorates fructose-induced hepatosteatosis by restraining hepatic lipogenesis via AMPK-dependent suppression of the SREBP-1/ACC/FASN cascade. Altogether, this study demonstrates that GA supplement may be a promising therapeutic strategy in NAFLD, especially in the subset with enhanced hepatic lipogenesis.

Metabolomics profiling of AKT/c-Met-induced hepatocellular carcinogenesis and the inhibitory effect of Cucurbitacin B in mice.

Hepatocellular carcinoma (HCC), the most common kind of liver cancer, accounts for the majority of liver cancer diagnoses and fatalities. Clinical aggressiveness, resistance to traditional therapy, and a high mortality rate are all features of this disease. Our previous studies have shown that co-activation of AKT and c-Met induces HCC development, which is the malignant biological feature of human HCC. Cucurbitacin B (CuB), a naturally occurring tetracyclic triterpenoid compound with potential antitumor activity. However, the metabolic mechanism of AKT/c-Met-induced Hepatocellular Carcinogenesis and CuB in HCC remains unclear. In this study, we established an HCC mouse model by hydrodynamically transfecting active AKT and c-Met proto-oncogenes. Based on the results of hematoxylin-eosin (H&E), oil red O (ORO) staining, and immunohistochemistry (IHC), HCC progression was divided into two stages: the early stage of HCC (3 weeks after AKT/c-Met injection) and the formative stage of HCC (6 weeks after AKT/c-Met injection), and the therapeutic effect of CuB was evaluated. Through UPLC-Q-TOF-MS/MS metabolomics, a total of 26 distinct metabolites were found in the early stage of HCC for serum samples, while in the formative stage of HCC, 36 distinct metabolites were found in serum samples, and 13 different metabolites were detected in liver samples. 33 metabolites in serum samples and 11 in live samples were affected by CuB administration. Additionally, metabolic pathways and western blotting analysis revealed that CuB influences lipid metabolism, amino acid metabolism, and glucose metabolism by altering the AKT/mTORC1 signaling pathway, hence decreasing tumor progression. This study provides a metabolic basis for the early diagnosis, therapy, and prognosis of HCC and the clinical application of CuB in HCC.

Luteolin alleviates methionine-choline-deficient diet-induced non-alcoholic steatohepatitis by modulating host serum metabolome and gut microbiome.

Background and purpose: Previous studies have indicated the protective effects of luteolin against non-alcoholic steatohepatitis (NASH), but the definite underlying mechanism still remains unclear. This study aimed to explore the metabolomic and metagenomic signatures of NASH with luteolin supplementation. Experimental approach: Mice were fed with a methionine-choline-deficient (MCD) diet containing 0.05% luteolin for 6 weeks. NASH severity was determined based on the liver histological observations, serum and hepatic biochemical measurements. Targeted metabolomics was conducted to identify differential metabolites in mice serum. 16S rRNA sequencing was conducted to assess the gut microbiota composition and function in mice colon. Results: In detail, luteolin treatment significantly alleviated MCD diet-induced hepatic lipid deposition, liver function damage, and oxidative stress. Targeted plasma metabolomics revealed that 5-hydroxyindole, LPE (0:0/22:5), indole 3-phosphate, and N-phenylacetylphenylalanine were remarkably elevated, and homogentisic acid, thiamine, KN-93, PC (16:1e/8, 9-EpETE), carnitine C9:1-OH, FFA (18:4) and carnitine C8:1 were significantly decreased in NASH group as compared to normal group, which could be profoundly reversed after luteolin treatment. 16S rRNA sequencing indicated that luteolin supplementation significantly increased Erysipelatoclostridium and Pseudomonas as well as decreased Faecalibaculum at genus level. Most importantly, a negative association between thiamine and Faecalibaculum was observed based on Spearman's correlation analysis, which may play an important role in the preventive effects of luteolin against NASH. Conclusion: Collectively, luteolin may alleviate the NASH by modulating serum metabolome and gut microbiome, which supports its use as a dietary supplement for NASH prevention.

Urolithin A Attenuates Hyperuricemic Nephropathy in Fructose-Fed Mice by Impairing STING-NLRP3 Axis-Mediated Inflammatory Response via Restoration of Parkin-Dependent Mitophagy.

Urolithin A (UroA) is one of the primary intestinal metabolites of ellagitannins, showing translational potential as a nutritional intervention in humans. Mounting evidence suggests that fructose consumption contributes to the progression of chronic kidney disease (CKD) that manifests in hyperuricemic nephropathy, renal inflammation, and tubulointerstitial injury. Here, we investigated the efficacy of UroA in alleviating fructose-induced hyperuricemic nephropathy in mice. Uric acid-exposed human kidney-2 (HK-2) cells were utilized for in vitro mechanism validation. Histopathological staining, immunoblotting, and transmission electron microscope were performed for the mechanistic investigations. Our results revealed that UroA ameliorated fructose-induced hyperuricemic nephropathy in mice. The histopathologic assessment showed that UroA attenuated tubular hypertrophy and dilation, glomerular basement membrane thickening, and collagen deposition in the kidney of fructose-fed mice. Mechanistically, UroA treatment impaired STING-NLRP3 activation, resulting in reduced production of proinflammatory cytokines IL-1ß, IL-6, and TNF-α. Notably, UroA exhibited a scavenging effect against reactive oxygen species (ROS) and restored fructose-impaired PINK1/Parkin-mediated mitophagy in nephropathic mice. Furthermore, the inhibitory effect of UroA in STING-NLRP3 activation was impaired after Parkin gene silencing in HK-2 cells. Together, this study suggests that UroA alleviates fructose-induced hyperuricemic nephropathy by promoting Parkin-dependent mitophagy, thereby suppressing STING-NLRP3 axis-mediated inflammatory response. Thus, dietary supplementation with UroA or ellagitannins-rich foods may serve as a promising intervention to prevent CKD progression.

Celecoxib attenuates hepatosteatosis by impairing de novo lipogenesis via Akt-dependent lipogenic pathway.

Mounting evidence indicates that hepatic de novo lipogenesis is a common abnormality in non-alcoholic fatty liver disease (NAFLD) patients. We investigated whether a selective COX-2 inhibitor, celecoxib, alleviates hepatic steatosis by targeting an Akt-driven lipogenic pathway. We estimated the efficacy of celecoxib in a novel Akt-driven NAFLD mouse model established via hydrodynamic transfection of activated forms of AKT and in fructose-fed NAFLD mice that exhibited increased insulin-independent hepatic lipogenesis. AKT-transfected and insulin-stimulated human hepatoma cells were used for the in vitro experiments. Haematoxylin and eosin staining, immunohistochemistry and immunoblotting were performed for mechanistic studies. The results revealed that celecoxib ameliorated hepatic steatosis in the AKT-triggered NAFLD mice. Mechanistically, celecoxib effectively suppressed AKT/mTORC1 signalling and its downstream lipogenic cascade in the Akt-driven NAFLD mice and in vitro. Furthermore, celecoxib had limited efficacy in alleviating hepatic lipid accumulation and showed no influence on lipogenic proteins associated with hepatic lipogenesis in fructose-administered mice. This study suggests that celecoxib may be favourable for the treatment of NAFLD, especially in the subset with Akt-triggered hepatic lipogenesis.

Caffeine Ameliorates AKT-Driven Nonalcoholic Steatohepatitis by Suppressing De Novo Lipogenesis and MyD88 Palmitoylation.

Dysregulated hepatic lipogenesis represents a promising druggable target for treating nonalcoholic steatohepatitis (NASH). This work aims to evaluate the therapeutic efficacy of caffeine in a NASH mouse model displaying increased hepatic lipogenesis driven by constitutive hepatic overexpression of the active v-akt murine thymoma viral oncogene homolog (AKT). Caffeine was administered in the AKT mice to study the efficacy in vivo. AKT-transfected and insulin-stimulated human hepatoma cells were used for in vitro experiments. The results demonstrated that caffeine ameliorated hepatic steatosis and inflammatory injury in vivo. Mechanistically, caffeine repressed the AKT/mTORC1 and SREBP-1/ACC/FASN signaling in mice and in vitro. Furthermore, caffeine impaired NF-κB activation by stabilizing IκBα, resulting in a reduction of proinflammatory mediators interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α). Notably, caffeine abolished mTORC1/FASN-dependent MyD88 palmitoylation, which could be essential for its anti-inflammatory potential. Collectively, these results suggest that caffeine consumption could be advantageous in the prevention and therapy of NASH, especially in the subset accompanied by increased de novo lipogenesis.