Steatosis is characterized by an increase in free fatty acids, such as palmitic acid (PA), in hepatocytes and the accumulation of triglycerides in the liver. However, the role of intracellular autophagy in PA accumulation-induced hepatotoxicity is not clearly understood. Therefore, in this study, we investigated the effects of PA on autophagy in hepatocytes and its underlying mechanism of action. Treatment of HepG2 cells with PA induced a significant increase in intracellular p62 and LC3-II levels, suggesting inhibition of autophagy. Furthermore, PA inhibited autophagic flux in HepG2 cells, as monitored using GFP-RFP-LC3. Mechanistically, PA increased the phosphorylation of the Ser12 and Thr29 residues of LC3, which are autophagy inhibition markers, through protein kinase A (PKA) and protein kinase C (PKC) signaling. Finally, PKA and PKC inhibitors restored PA-induced autophagic flux inhibition, reduced intracellular lipid accumulation, and rescued the altered expression of lipogenic genes, such as SREBP-1c, in HepG2 cells. Thus, our study demonstrates the mechanism of autophagy inhibition by PA in hepatocytes and provides a potential therapeutic approach for preventing and treating hepatic steatosis.

Hepatic glucolipotoxicity, characterized by the synergistic detrimental effects of elevated glucose levels combined with excessive lipid accumulation in hepatocytes, plays a central role in the pathogenesis of various metabolic liver diseases. Despite recent advancements, the precise mechanisms underlying this process remain unclear. Using cultured AML12 and HepG2 cells exposed to excess palmitate, with and without high glucose, as an in vitro model, we aimed to elucidate the cellular and molecular mechanisms underlying hepatic glucolipotoxicity. Our data showed that palmitate exposure induced the integrated stress response (ISR) in hepatocytes, evidenced by increased eukaryotic translation initiation factor 2 alpha (eIF2α) phosphorylation (serine 51) and upregulated activating transcription factor 4 (ATF4) expression. Moreover, we identified mammalian target of rapamycin complex 1 (mTORC1) as a novel upstream kinase responsible for palmitate-triggered ISR induction. Furthermore, we showed that either mTORC1 inhibitors, ISRIB (an ISR inhibitor), or ATF4 knockdown abolished palmitate-induced cell death, indicating that the mTORC1-eIF2α-ATF4 pathway activation plays a mechanistic role in mediating palmitate-induced hepatocyte cell death. Our continuous investigations revealed that glycerol-3-phosphate acyltransferase (GPAT4)-mediated metabolic flux of palmitate into the glycerolipid synthesis pathway is required for palmitate-induced mTORC1 activation and subsequent ISR induction. Specifically, we uncovered that saturated phosphatidic acid production contributes to palmitate-triggered mTORC1 activation. Our study provides the first evidence that high glucose enhances palmitate-induced activation of the mTORC1-eIF2α-ATF4 pathway, thereby exacerbating palmitate-induced hepatotoxicity. This effect is mediated by the increased availability of glycerol-3-phosphate, a substrate essential for phosphatidic acid synthesis. In conclusion, our study highlights that the activation of the mTORC1-eIF2α-ATF4 pathway, driven by saturated phosphatidic acid overproduction, plays a mechanistic role in hepatic glucolipotoxicity.NEW & NOTEWORTHY Integrated stress response (ISR) activation contributes to palmitate-induced lipotoxicity in hepatocytes. mTORC1 acts as an upstream kinase essential for palmitate-mediated ISR activation and hepatocyte death. The formation of saturated phosphatidic acid mechanistically regulates hepatic mTORC1 activation induced by palmitate. Glucose-enhanced generation of saturated phosphatidic acid amplifies palmitate-induced hepatotoxicity, contributing to glucolipotoxicity.

Nonalcoholic steatohepatitis (NASH) is a combination of hepatic steatosis, inflammation, and fibrosis, and it often follows simple hepatic steatosis in nonalcoholic fatty liver disease (NAFLD). However, no pharmacological treatment is currently available for NASH. Given the important role of TFEB (transcription factor EB) in regulating the macroautophagy/autophagy-lysosomal pathway, TFEB is potentially a novel therapeutic target for treatment of NASH, which function can be regulated by AMP-activated protein kinase (AMPK) and MTOR (mechanistic target of rapamycin kinase) complex 1 (MTORC1). Buddleoside (Bud), a natural flavonoid compound, has recently emerged as a promising drug candidate for liver diseases. Here, we shown that Bud treatment alleviated hepatic steatosis, insulin resistance, inflammation, and fibrosis in mice fed a high-fat and high-cholesterol (HFHC) diet. Notably, Bud activated AMPK, inhibited MTORC1, and enhanced TFEB transcriptional activity as well as autophagic flux in vivo and in vitro. Inhibition of AMPK or knockout of hepatic Tfeb abrogated the alleviation effects of Bud on hepatic steatosis, insulin resistance, inflammation, and fibrosis. Mechanistic investigation revealed that Bud bound to the PRKAB1 subunit via Val81, Arg83, and Ser108 residues and activated AMPK, thereby eliciting phosphorylation of RPTOR (regulatory associated protein of MTOR complex 1) and inhibiting the kinase MTORC1, which activated the TFEB-mediated autophagy-lysosomal pathway and further ameliorated HFHC-induced NASH in mice. Altogether, our results indicate that Bud ameliorates NASH by activating hepatic the AMPK-TFEB axis, suggesting that Bud is a potential therapeutic strategy for NASH.Abbreviations: ACAC, acetyl-CoA carboxylase; ADaM, allosteric drug and metabolite; AICAR, 5-aminoimidazole-4-carboxamide1-β-D-ribofuranoside; AKT, AKT serine/threonine kinase; ALP, autophagy-lysosomal pathway; AMPK, AMP-activated protein kinase; Bud, buddleoside; CAMKK2, calcium/calmodulin dependent protein kinase kinase 2; CC, compound C; CETSA, cellular thermal shift assay; Cmax, maximum concentration; CQ, chloroquine; DARTS, drug affinity responsive target stability assay; EIF4EBP1, eukaryotic translation factor 4E binding protein 1; GOT1, glutamic-oxaloacetic transaminase 1; GPT, glutamic-pyruvic transaminase; GSK3B, glycogen synthase kinase 3 beta; GTT, glucose-tolerance test; HFD, high fat diet; HFHC, high-fat and high-cholesterol; HOMA-IR, homeostasis model assessment of insulin resistance; IKBKB, inhibitor of nuclear factor kappa B kinase subunit beta; INSR, insulin receptor; ITT, insulin-tolerance test; LDH, lactate dehydrogenase; STK11, serine/threonine kinase 11; MAP1LC3/LC3, microtubule associated protein 1 light chain 3; MTORC1, MTOR complex 1; NAFLD, non-alcoholic fatty liver disease; NASH, non-alcoholic steatohepatitis; ND, normal diet; NFKB, nuclear factor kappa B; PA, palmitic acid; PSR, picrosirius red; RRAG, Ras related GTP binding; RPTOR, regulatory associated protein of MTOR complex 1; RPS6, ribosomal protein S6; RPS6KB, ribosomal protein S6 kinase B; SMAD2, SMAD family member 2; SMAD3, SMAD family member 3; SQSTM1, sequestosome 1; TFEB, transcription factor EB; tfeb-HKO, hepatocyte-specific tfeb knockout; TSC2, TSC complex subunit 2.

Resolvin D5 (RD5), a lipid mediator derived from DHA via 5-lipoxygenase signaling, has been shown to resolve inflammation in various disease models. This study aimed to investigate the role of RD5 in the development of hepatic steatosis in individuals with obesity and explore the detailed mechanisms involved. Protein expression was evaluated via Western blot analysis, whereas hepatic lipid deposition was examined via Oil Red O staining and triglyceride quantification. Autophagosomes were detected via MDC staining. Our findings indicated that RD5 treatment normalized lipogenic lipid accumulation, fatty acid uptake, oxidation, apoptosis, and endoplasmic reticulum (ER) stress in palmitate-treated primary hepatocytes. As a cytoprotective signaling pathway, RD5 treatment increased the expression of SIRT6 and autophagy markers, such as those involved in LC3 conversion and p62 degradation. The beneficial effects of RD5 on hepatic lipid metabolism, apoptosis, and ER stress were negated by SIRT6 small interfering RNA or 3-methyladenine, an inhibitor of autophagy. Furthermore, RD5 administration decreased hepatic steatosis, apoptosis, and ER stress in the livers of high-fat diet (HFD)-fed mice. In line with the in vitro results, RD5 treatment elevated SIRT6 and autophagy levels in the livers of HFD-fed mice. These novel findings suggest that RD5 improves hepatic lipid metabolism, apoptosis and ER stress through SIRT6/autophagy signaling, thereby attenuating hepatic steatosis. RD5 may have therapeutic potential for treating nonalcoholic fatty liver disease with minimal side effects.

Acute lung injury (ALI), including its most severe form, acute respiratory distress syndrome (ARDS), is a common cause of acute hypoxemic respiratory failure. Although its clinical characteristics have been well characterized, the relevant mechanism remains unclear. An imbalance in autophagy leads to alveolar remodeling and triggers the pathogenesis of ARDS. In this study, we assessed the therapeutic efficacy of the STAT1 inhibitor fludarabine (Fluda) in ALI. C57BL6 mice were exposed to lipopolysaccharide (LPS), and their lung tissues were analyzed via next-generation transcriptome sequencing.

Western blotting revealed that interferon regulatory factor 1 (IRF1) was highly expressed and STAT1 was phosphorylated following LPS exposure. Fluda significantly decreased the protein expression of STAT1/IRF1 and inhibited the alveolar infiltration of neutrophils and macrophages. Nitric oxide (NO), inducible nitric oxide synthase, tumor necrosis factor-α (TNF-α), interferon-γ, and interleukin-6 (IL-6) release was decreased in the lungs of mice and RAW264.7 macrophages following Fluda treatment. In LPS-induced GFP-LC3 transgenic mice treated with Fluda, the counts of LC3-expressing neutrophils and macrophages in bronchoalveolar (BAL) fluid were significantly decreased. Furthermore, Fluda decreased LC3 and p62 protein expression, thereby inhibiting the release of NO, IL-6, and TNF-α in BAL. In RAW264.7 cells, the inhibition of STAT1/IRF1 by Fluda decreased LPS-induced ERK and NF-κB p65 phosphorylation.

The inhibition of STAT1/IRF1 by Fluda plays a pivotal role in modulating dysregulated autophagy by suppressing the MAPK and NF-κB p65 pathways in ALI.

Chlorpyrifos (CPF) is a widely used organophosphate (OP) pesticide in agriculture and sanitation, known to elicit neurotoxic effects. Chlorpyrifos-oxon (CPO), a metabolite of CPF, is the primary neurotoxic agent, yet its mechanisms are less understood. In this study, we investigated the effects and underlying mechanisms of CPO-induced neurotoxicity. CPO exposure significantly induced cytotoxicity in Neuro-2a cells, alongside the activation of apoptosis, as evidenced by an increase in the apoptotic cell population, caspase-3 activity, and cleavage of caspaspe-3, -7, and PARP proteins. Furthermore, defective autophagy was observed in CPO-treated Neuro-2a cells, indicated by increased expression of Beclin-1, Atg5, LC3-II, and p62 proteins. 3-MA, an autophagy inhibitor, suppressed CPO-activated LC3-II and apoptotic marker proteins expression, but not p62. In contrast, chloroquine and bafilomycin A1, autophagic flux inhibitors, potentiated the CPO-induced elevation of LC3-II, p62, and cleaved caspase-3 and -7 protein levels. CPO exposure also upregulated CHOP protein expression. Transfection with CHOP-specific siRNA markedly reduced CHOP protein expression, autophagic flux dysfunction, and apoptosis. Additionally, CPO exposure significantly increased AMPKα phosphorylation and reactive oxygen species (ROS) generation. Antioxidant N-acetylcysteine (NAC), but not the AMPK inhibitor Compound C, effectively attenuated the CPO-induced ROS generation in neuronal cells, which was accompanied by the prevention of AMPKα activation, downstream CHOP expression, autophagic flux dysfunction, and apoptosis. Collectively, these findings suggest that CPO-induced neurotoxicity arises from autophagic flux dysfunction, contributing to apoptosis via the ROS-activated AMPK pathway, which regulates CHOP expression, ultimately leading to neuronal cell death. Targeting the ROS/AMPK/CHOP axis may offer a promising intervention to against CPO-induced neurotoxicity.

An overdose of acetaminophen (APAP) is the leading cause of drug-induced hepatotoxicity and acute liver failure in the United States. It is established that the predominant mode of hepatocyte cell death after an APAP overdose is through necrosis, and it is now recognized that this occurs through regulated pathways involving RIP kinases. These kinases, along with the pseudo-kinase MLKL, are central players in classical necroptotic cell death. Despite the skepticism regarding the role of necroptosis in APAP-induced liver injury, recent research demonstrating necroptosis-independent roles for MLKL led us to re-examine the role of this pseudo-kinase in APAP pathophysiology. Treatment of Mlkl-/- mice with a moderate (300 mg/kg) overdose of APAP resulted in an exacerbation of liver injury at 6- and 12-h post-APAP as evidenced by elevated plasma alanine aminotransferase activities, and extensive necrosis accompanied by diminished glutathione levels. Interestingly, these differences between Mlkl-/- and wild-type mice were negated at the 24-h mark, previously scrutinized by others. At 6 and 12 h post-APAP, Mlkl-/- mice exhibited augmented translocation of AIF and Endonuclease G without affecting JNK activation, suggesting enhanced mitochondrial permeability transition in the absence of MLKL. Lack of MLKL also impacted autophagy, the unfolded protein response and endoplasmic reticulum stress, with decreased levels of p62 and LC3B and increased expression of CHOP and GRP78 at 6 h post-APAP. In essence, our findings illuminate a noncanonical role for MLKL in the early phases of APAP-induced liver injury, warranting further exploration of its influence on APAP pathophysiology.

This study investigated the late effects of maternal protein restriction (MPR) and early postnatal sugar consumption on liver health in male Sprague-Dawley rat offspring, focusing on changes observed throughout the aging process. The animals were divided into the following groups: Control (CTR): Male offspring whose dams consumed a normal protein diet (NPD, 17% protein) and water ad libitum during gestation and lactation, and then fed a NPD and water until PND 540; Control + Sugar (CTR + SUG): The same treatment as CTR, but consuming a sugar solution (10% diluted in water) from postnatal day (PND) 21-90, and then fed a NPD and water until PND 540; Gestational and Lactational Low Protein (GLLP): Male offspring whose dams consumed a low-protein diet (LPD, 6% protein) during gestation and lactation and, then fed a NPD and water ad libitum until PND 540; Gestational and Lactational Low Protein + Sugar (GLLP + SUG): male offspring whose dams consumed a LPD during gestation and lactation, and then fed a NPD and a sugar solution (10% diluted in water) ad libitum from PND 21 to 90. On PND 540, the animals were anesthetized, weighed, and euthanized, and their livers were collected for morphological and molecular analyses. The GLLP and GLLP + SUG groups showed lower body weight and lower retroperitoneal fat weight compared to the CTR and CTR + SUG groups. Morphological analysis revealed inflammatory foci in the liver from the CTR + SUG, GLLP, and GLLP + SUG groups, compared to the CTR group. Hepatic activities of CAT, SOD, and GSH-Px were increased in the GLLP + SUG group and decreased in the GLLP group, compared to the CTR group. Immunohistochemistry showed a significant increase in occupied area per foci de hepatocytes positive for GSTpi (placental form) in the CTR + SUG, GLLP, and GLLP + SUG groups, compared to the CTR group. Proteomic analysis of the groups revealed significant changes in hepatic metabolic and inflammatory pathways. In the CTR + SUG group, upregulated pathways associated with non-alcoholic fatty liver disease (NAFLD) and downregulated pathways related to autophagy were observed. In the GLLP and GLLP + SUG groups, there was a significant impact on metabolic pathways, including glucose metabolism, gluconeogenesis, glycogenesis, and cellular stress responses. An upregulation of pathways associated with chemokine- and cytokine-mediated inflammatory processes was also identified, indicating activation of the immune system in the liver during aging. Therefore, MPR, with or without postnatal sugar consumption, resulted in hepatic changes in metabolism and the antioxidant defense in old male offspring.

Metabolic dysfunction-associated steatohepatitis (MASH), a severe form of metabolic dysfunction-associated steatotic liver disease (MASLD), involves hepatic lipid accumulation, inflammation, and fibrosis. It can progress to cirrhosis or hepatocellular carcinoma without timely treatment. Current treatment options for MASH are limited. This study explores the therapeutic effects of fluorofenidone (AKF-PD), a novel small-molecule compound with antifibrotic and anti-inflammatory properties, on MASH in mouse model. Mice fed a choline-deficient, l-amino acid-defined, high-fat diet (CDAHFD) were treated with AKF-PD, resulting in reduced serum ALT, AST, hepatic lipid accumulation, liver inflammation, and fibrosis. Network pharmacology and RNA-sequencing analyses suggested that AKF-PD influenced multiple metabolic, inflammatory, and fibrosis-related pathways. Further experiments verified that AKF-PD activated hepatic AMPK signaling, leading to the inhibition of the downstream SREBF1/SCD1 pathway and the activation of autophagy. Additionally, AKF-PD suppressed the expression of various inflammatory factors, reduced macrophage infiltration, and inhibited NLRP3 inflammasome activation. Moreover, AKF-PD attenuated liver fibrosis by inhibiting TGFβ1/SMAD signaling. In conclusion, this study reveals that AKF-PD effectively decreases hepatic lipid accumulation, liver inflammation and fibrosis in a CDAHFD-induced MASH model, positioning AKF-PD as a promising candidate for the treatment of MASH.

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a clinical-pathological syndrome primarily characterized by excessive accumulation of fat in hepatocytes, independent of alcohol consumption and other well-established hepatotoxic agents. Mitochondrial dysfunction is widely acknowledged as a pivotal factor in the pathogenesis of various diseases, including cardiovascular diseases, cancer, neurodegenerative disorders, and metabolic diseases such as obesity and obesity-associated MAFLD. Mitochondria are dynamic cellular organelles capable of modifying their functions and structures to accommodate the metabolic demands of cells. In the context of MAFLD, the excess production of reactive oxygen species induces oxidative stress, leading to mitochondrial dysfunction, which subsequently promotes metabolic disorders, fat accumulation, and the infiltration of inflammatory cells in liver and adipose tissue. This review aims to systematically analyze the role of mitochondria-targeted therapies in MAFLD, evaluate current therapeutic strategies, and explore future directions in this rapidly evolving field. We specifically focus on the molecular mechanisms underlying mitochondrial dysfunction, emerging therapeutic approaches, and their clinical implications. This is of significant importance for the development of new therapeutic approaches for these metabolic disorders.

Flutamide (FL), a non-steroidal drug used for its antiandrogenic, anticancer, and disrupting endocrine properties, induces mitochondrial toxicity and drug metabolism enzymes and promotes hepatocarcinogenesis. The inhibition of mitophagy, leading to the accumulation of damaged mitochondria, is implicated in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). In this study, we investigated the effects of FL in high-fat diet (HFD)-induced non-obese steatosis rats, categorized into four groups: basal diet (BD), BD + FL, HFD, and HFD + FL. The FL exacerbated HFD-induced steatosis and marginally increased preneoplastic lesions. To analyze hepatic preneoplastic lesions, we divided them into clusters based on the expression ratios of the mitophagy regulators LC3 and AMBRA1. The expression rates of LC3 and AMBRA1 in these precancerous lesions were classified into three clusters using k-means clustering. The HFD group exhibited an increased ratio of mitophagy inhibition clusters, as indicated by decreased LC3 and increased AMBRA1 levels in background hepatocytes and preneoplastic lesions. FL counteracted HFD-mediated mitophagy inhibition, as indicated by increased LC3 and decreased AMBRA1 levels in background hepatocytes. Our clustering analysis revealed that FL-induced mitophagy induction relied on Parkin expression. The present study underscores the significance of cluster analysis in understanding the role of mitophagy within small preneoplastic lesions and suggests that FL may potentially exacerbate NAFLD-associated hepatocarcinogenesis by affecting mitophagy.

Endoplasmic reticulum (ER) stores Ca2+ and plays crucial roles in protein folding, lipid transfer, and it's perturbations trigger an ER stress. In the liver, chronic ER stress is involved in the pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH). Dysfunction of sarco/endoplasmic reticulum calcium ATPase (SERCA2), a key regulator of Ca2+ transport from the cytosol to ER, is associated with the induction of ER stress and lipid droplet formation. We previously identified NACHT and WD repeat domain-containing protein 1 (Nwd1) localized at the ER and mitochondria. However, the physiological significance of Nwd1 outside the brain remains unclear. In this study, we revealed that Nwd1-/- mice exhibited pathological manifestations comparable to MASH. Nwd1 interacts with SERCA2 near ER membranes. Nwd1-/- livers exhibited reduced SERCA2 ATPase activity and a smaller Ca2+ pool in the ER, leading to an exacerbated state of ER stress. These findings highlight the importance of SERCA2 activity mediated by Nwd1 in the pathogenesis of MASH.

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a range of conditions that start with the accumulation of fat in the liver (hepatic steatosis) and can progress to more severe stages like steatohepatitis (NASH) and fibrosis without drinking alcohol. Environmental and genetic variables both contribute to MAFLD's development, with various biological processes and mediators involved at every phase. Long non-coding RNAs (lncRNAs) are a class of RNA molecules that are not translated into protein and are over 200 nucleotides long. They can impact genes that encode protein by controlling transcriptional and post-transcriptional procedures. Dysregulation of lncRNA has been connected to several liver diseases, including MAFLD. Recent research has linked lncRNAs to MAFLD pathology in both patients and animal models. However, the roles of most lncRNAs in MAFLD pathology are still not well recognized. This review provides a comprehensive catalog of recently reported lncRNAs in the pathogenesis of MAFLD and summarizes the current knowledge of lncRNAs usage as therapeutic strategies in MAFLD, the most common liver disease. Collectively, lncRNA's targeting could potentially offer a therapeutic approach by modulating MAFLD.

Disruption of hepatic lipid homeostasis leads to excessive hepatic triglyceride accumulation and the development of metabolic dysfunction-associated steatotic liver disease (MASLD). Autophagy, a critical process in liver lipid metabolism, is impaired in MASLD pathogenesis. Irisin, a skeletal muscle-driven myokine, regulates lipid metabolism, but its impact on hepatic lipid metabolism is not well understood. Here, we aimed to explore the role of irisin in hepatic steatosis and the underlying mechanisms involved.

A high-fat diet (HFD)-induced MASLD mouse model was used, and the recombinant irisin protein, herein referred to as "Irisin", was intraperitoneally administered for 4 weeks to evaluate the effects of irisin on hepatic lipid accumulation. Liver tissues were stained with Oil red O (ORO), and triglyceride (TG) and total cholesterol (TC) contents were measured in serum and liver homogenates. The expression of the autophagosome marker microtubule-associated protein 1 light chain 3 (LC3), the autophagy receptor protein sequestosome-1 (SQSTM1/p62), autophagy initiation complex unc-51-like kinase 1 (ULK1) and the lysosomal functional protein cathepsin B was measured via Western blotting, and the expression of the transcription factor EB (TFEB) was analyzed via immunofluorescence to explore autophagic changes. The effect of irisin on autophagic flux was further evaluated in palmitic acid-induced HepG2 cells by measuring autophagic degradation with chloroquine (CQ), and analyzing the colocalization of LC3 and lysosome-associated protein 1 (LAMP1). The possible mechanism was examined by measuring the expression of the autophagic sirtuin 3 (SIRT3) pathway and further validated using overexpression of SIRT3 with plasmid transfection or siRNA-mediated knockdown. Student's t-test was utilized for statistical analysis.

Irisin significantly reduces hepatic lipid accumulation in mice fed with HFD, accompanied by enhanced hepatocyte autophagy and upregulation of the SIRT3 pathway. In HepG2 cells, Irisin attenuated palmitic acid-induced lipid accumulation, which was partially dependent on SIRT3 levels. Mechanistically, Irisin treatment upregulated SIRT3 and phosphorylated AMP-activated protein kinase (AMPK), inhibited mammalian target of rapamycin (mTOR) activity, promoted TFEB nucleus translocation, increased cathepsin B expression, enhanced autophagic degradation, and alleviated hepatic steatosis. No significant changes in phosphorylation of ULK1 in the hepatocytes were observed. However, when siRNA was used to knock down SIRT3, the changes of those protein were partially reversed, and hepatic steatosis was further exacerbated.

Our findings highlight irisin as a potential therapeutic for hepatic steatosis by modulating autophagy and lipid metabolism, potentially providing a novel therapeutic target for the management of MASLD. Further research is needed to elucidate the underlying mechanisms and explore the potential clinical applications of this approach in the treatment of MASLD.

Despite the worldwide surge in the prevalence of non-alcoholic fatty liver disease (NAFLD), however, no efficacious treatment has been clinically approved to date for combating this condition, necessitating elucidation of new therapeutic compounds. Our research presented evidence pertaining to the successful induction of NAFLD in C57BL/6 mice using a multiple liver insults paradigm. This was achieved by concurrently administering thioacetamide (100 mg/kg i.p.) along with high-fat and high-fructose diet (HFFrD) for 10 weeks. Following this, the beneficial effect of borneol, a bicyclic monoterpenoid, was observed in NAFLD mice in a dose-dependent manner. Borneol administration for 4 weeks led to significant improvement in morphometric, metabolic profiles, liver functions, and oxidative stress parameters. Accumulation of lipids in hepatic tissues, which is characteristic feature of NAFLD, was confirmed by H&E, as well as oil-red O staining was alleviated by borneol. Our investigation elucidated the pro-autophagic effect of borneol via AMPK activation, thereby leading to the downstream activation of autophagy effector proteins, that is, Beclin1, ATG5, ATG7, and LC3 I-II, which helps to diminish the hepatic lipid loads through augmentation of lipophagy. This study demonstrates that borneol combats NAFLD through augmentation of AMPK-mediated lipophagy offering a promising therapeutic strategy against NAFLD.

The global rise in Metabolic dysfunction-associated steatotic liver disease (MASLD)/Metabolic dysfunction-associated steatohepatitis (MASH) highlights the urgent necessity for noninvasive biomarkers to detect these conditions early. To address this, we endeavored to construct a diagnostic model for MASLD/MASH using a combination of bioinformatics, molecular/biochemical data, and machine learning techniques. Initially, bioinformatics analysis was employed to identify RNA molecules associated with MASLD/MASH pathogenesis and enriched in ferroptosis and exophagy. This analysis unveiled specific networks related to ferroptosis (GPX4, LPCAT3, ACSL4, miR-4266, and LINC00442) and exophagy (TSG101, HGS, SNF8, miR-4498, miR-5189-5p, and CTBP1-AS2). Subsequently, serum samples from 400 participants (151 healthy, 150 MASH, and 99 MASLD) underwent biochemical and molecular analysis, revealing significant dyslipidemia, impaired liver function, and disrupted glycemic indicators in MASLD/MASH patients compared to healthy controls. Molecular analysis indicated increased expression of LPCAT3, ACSL4, TSG101, HGS, and SNF8, alongside decreased GPX4 levels in MASH and MASLD patients compared to controls. The expression of epigenetic regulators from both networks (miR-4498, miR-5189-5p, miR-4266, LINC00442, and CTBP1-AS2) significantly differed among the studied groups. Finally, supervised machine learning models, including Neural Networks and Random Forest, were applied to molecular signatures and clinical/biochemical data. The Random Forest model exhibited superior performance, and molecular features effectively distinguished between the three studied groups. Clinical features, particularly BMI, consistently served as discriminatory factors, while biochemical features exhibited varying discriminant behavior across MASH, MASLD, and control groups. Our study underscores the significant potential of integrating diverse data types to enable early detection of MASLD/MASH, offering a promising approach for non-invasive diagnostic strategies.

Increased entropy is a common cause of disease and aging. Lifespan entropy is the overall increase in disorder caused by a person over their lifetime. Aging leads to the excessive production of reactive oxygen species (ROS), which damage the antioxidant system and disrupt redox balance. Organ aging causes chronic inflammation, disrupting the balance of proinflammatory and anti-inflammatory factors. Inflammaging, which is a chronic low-grade inflammatory state, is activated by oxidative stress and can lead to immune system senescence. During this process, entropy increases significantly as the body transitions from a state of low order to high disorder. However, the connection among inflammation, aging, and immune system activity is still not fully understood. This review introduces the idea of the ROS-inflammation-immune balance for the first time and suggests that this balance may be connected to aging and the development of age-related diseases. We also explored how the balance of these three factors controls and affects age-related diseases. Moreover, imbalance in the relationship described above disrupts the regular structures of cells and alters their functions, leading to cellular damage and the emergence of a disorganized state marked by increased entropy. Maintaining a low entropy state is crucial for preventing and reversing aging processes. Consequently, we examined the current preclinical evidence for antiaging medications that target this balance. Ultimately, comprehending the intricate relationships between these three factors and the risk of age-related diseases in organisms will aid in the development of clinical interventions that promote long-term health.

Among genetic disorders of vesicular trafficking, there are three causing recurrent acute liver failure (RALF): NBAS, RINT1, and SCYL1-associated disease. These three disorders are characterized by liver crises triggered by febrile infections and account for a relevant proportion of RALF causes. While the frequency and severity of liver crises in NBAS and RINT1-associated disease decrease with age, patients with SCYL1 variants present with a progressive, cholestatic course. In all three diseases, there is a multisystemic, partially overlapping phenotype with variable expression, including liver, skeletal, and nervous systems, all organ systems with high secretory activity. There are no specific biomarkers for these diseases, and whole exome sequencing should be performed in patients with RALF of unknown etiology. NBAS, SCYL1, and RINT1 are involved in antegrade and retrograde vesicular trafficking. Pathomechanisms remain unclarified, but there is evidence of a decrease in concentration and stability of the protein primarily affected by the respective gene defect and its interaction partners, potentially causing impairment of vesicular transport. The impairment of protein secretion by compromised antegrade transport provides a possible explanation for different organ manifestations such as bone alteration due to lack of collagens or diabetes mellitus when insulin secretion is affected. Dysfunction of retrograde transport impairs membrane recycling and autophagy. The impairment of vesicular trafficking results in increased endoplasmic reticulum stress, which, in hepatocytes, can progress to hepatocytolysis. While there is no curative therapy, an early and consequent implementation of an emergency protocol seems crucial for optimal therapeutic management.

Recent research has illuminated the pivotal role of the hypoxia-inducible factor-2α (HIF-2α)/peroxisome proliferator-activated receptor alpha (PPARα) pathway in the progression of nonalcoholic fatty liver disease (NAFLD). Meanwhile, it has been reported that HIF-2α is involved in iron regulation, and that aberrant iron distribution leads to liver lipogenesis. Therefore, we hypothesize that HIF-2α exacerbates fatty liver by affecting iron distribution. To substantiate this hypothesis, we utilized liver-specific HIF-2α knockout mice and the LO2 cell line with overexpressed HIF-2α. HIF-2α overexpression (OE) was induced via lentiviral infection, followed by exposure to free fatty acids (FFAs) and deferoxamine (DFO). In animal experiments, hepatic HIF-2α knockout resulted in lower liver lipid levels, lower liver weight, and higher serum iron levels. Enrichment in autophagy, ferroptosis, and the PI3K-AKT pathway was demonstrated through Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis in the liver of mice. In vitro experiments showed that HIF-2α increased supernatant iron. In the HIF-2α OE group, the addition of FFA led to decreased levels of reduced glutathione (GSH) and glutathione peroxidase 4 (GPX4) protein, along with increased lipid peroxidation (LPO), cellular lipid droplets, and triglyceride content. Impressively, DFO intervention decreased supernatant iron, reversed these changes by increasing GSH and GPX4 levels, and simultaneously reduced LPO levels, cellular lipid droplets, and triglyceride content. In addition, the expression of proteins related to β-oxidation increased, and lipid deposition in hepatocytes improved, which may be associated with the PI3K/AKT pathway. In summary, our findings suggest that HIF-2α-mediated iron flux enhances NAFLD cell susceptibility to ferroptosis, thereby impacting lipid metabolism-related genes and contributing to lipid accumulation.NEW & NOTEWORTHY The experiment demonstrated that HIF-2α increased extracellular iron. In LO2 cells overexpressing HIF-2α, FFAs not only increased cellular lipid and triglyceride levels but also induced key features of ferroptosis, such as reduced GSH and GPX4 levels and increased LPO, despite the absence of cellular iron overload. These effects were reversed by lowering extracellular iron with DFO. Furthermore, DFO treatment increased β-oxidation protein expression and improved lipid deposition in hepatocytes, potentially through the PI3K/AKT pathway.

Nonalcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide, whereas there is no approved drug therapy due to its complexity. Studies are emerging to discuss the role of selective autophagy in the pathogenesis of NAFLD, because the specificity among the features of selective autophagy makes it a crucial process in mitigating hepatocyte damage caused by aberrant accumulation of dysfunctional organelles, for which no other pathway can compensate.

This review aims to summarize the types, functions, and dynamics of selective autophagy that are of particular importance in the initiation and progression of NAFLD. And on this basis, the review outlines the therapeutic strategies against NAFLD, in particular the medications and potential natural products that can modulate selective autophagy in the pathogenesis of this disease.

The critical roles of lipophagy and mitophagy in the pathogenesis of NAFLD are well established, while reticulophagy and pexophagy are still being identified in this disease due to the insufficient understanding of their molecular details. As gradual blockage of autophagic flux reveals the complexity of NAFLD, studies unraveling the underlying mechanisms have made it possible to successfully treat NAFLD with multiple pharmacological compounds that target associated pathways. Overall, it is convinced that the continued research into selective autophagy occurring in NAFLD will further enhance the understanding of the pathogenesis and uncover novel therapeutic targets.

Neuropathy occurs due to damage to the peripheral/central nervous system either due to injury, disease, or drug usage. Increased endoplasmic reticulum (ER) stress is observed in neuropathy. ER stress also leads to a block in autophagy amplifying neuropathic pain. 6-Bromoindirubin-3'-oxime (6-BIO) is an inhibitor of GSK-3β which suppresses mTOR activity thereby increasing autophagy. Tunicamycin (TM)-mediated ER stress and diabetic rat models were used to elucidate the role of ER stress and autophagy in mitigation of neuropathic pain by 6-BIO. Pain was assessed by behavioral studies in ER stressed/diabetic rats having neuropathy. Western blotting, RT-PCR, and fluorescence microscopy were used to assess the level of autophagy and ER stress after TM and 6-BIO treatment in SH-SY5Y neurons. Intraplantar injection of TM in rats led to peripheral neuropathy which was reduced upon 6-BIO injection. 6-BIO also reduced pain in animals exhibiting diabetic peripheral neuropathy. Modulation in the markers of autophagy (p-mTOR, LC-3, and SQSTM1/p62) shows that 6-BIO induces autophagolysosome formation post TM treatment. Concomitantly, 6-BIO reduces ER stress and c-Fos expression-a neuronal activity and pain marker. Alleviation of pain by the inhibition of ER stress and increased formation of autolysosomes by 6-BIO can be harnessed for treating peripheral neuropathy.

Non-alcoholic fatty liver disease (NAFLD) is a common chronic disease seriously threatening human health, with limited treatment means, however. Sesamin, a common lignan in sesame seed oil, exhibits anti-inflammatory, antioxidant, and anticancer properties. Our previous studies have shown an ameliorative effect of sesamin on lipid accumulation in human hepatocellular carcinoma (HePG2) induced by oleic acid, with its protective effects unclear in the case of 9-trans-C18:1 elaidic acid (9-trans-C18,1).

L02 cells, an important tool in scientific researches due to its high proliferation ability, preserved hepatocyte function, and specificity in response to exogenous factors, were incubated with 9-trans-C18:1 to establish an in vitro model of NAFLD in our study. The lipid accumulation in cells and the morphology of mitochondria and autolysosomes were observed by Oil Red O staining and transmission electron microscopy. The effects of sesamin on oxidative stress, apoptosis, mitochondrial function, autophagy as well as related protein levels in L02 cells were also investigated in the presence of 9-trans-C18:1.

The results showed that sesamin significantly accelerated the autophagy flux of L02 cells induced by 9-trans-C18:1 as well as elevated protein levels of transcription factor EB (TFEB) and its downstream target lysosome-associated membrane protein 1(LAMP1), along with up-regulated levels of TFEB and LAMP1 in the nucleus indicated by Immunofluorescence. In addition, PTEN-induced putative kinase 1 and Parkin mediated mitophagy was activated by sesamin. The direct inhibitor Eltrombopag and indirect inhibitor MHY1485 of TFEB reversed the protective effect of sesamin, suggesting the involvement of autophagy in the lipid-lowering process of sesamin.

This work suggests that sesamin regulates autophagy through TFEB to alleviate lipid accumulation in L02 cells induced by 9-trans-C18:1, providing a potential target for the prevention and treatment of NAFLD.

Background/Objectives: Non-alcoholic fatty liver disease (NAFLD) is a major metabolic disorder with no established pharmacotherapy. Quercetin, a polyphenolic flavonoid, demonstrates potential hepatoprotective effects but has limited bioavailability. This study evaluates the impact of quercetin on NAFLD and assesses the roles of autophagy-related proteins in disease progression. Methods: Forty-seven male C57BL/6J mice were fed a high-fat diet (HFD) for 12 weeks to induce NAFLD, followed by quercetin treatment for 4 weeks. Mice were divided into baseline, control, and two quercetin groups, receiving low (10 mg/kg) and high (50 mg/kg) doses. Liver histology was scored using the NAFLD Activity Score (NAS). Immunohistochemistry and immunoblotting were performed to analyze autophagy markers. Results: Quercetin-treated groups showed significant reductions in NAS compared to controls (p = 0.011), mainly in steatosis and steatohepatitis. Immunohistochemistry indicated increased expression of autophagy markers LCA and p62 in quercetin groups. Western blot analysis revealed significant elevations in LC3A in the treated groups, suggesting improved autophagic activity and lipid degradation. Conclusions: Quercetin effectively reduces NAFLD severity and modulates autophagy-related proteins. These findings suggest that quercetin enhances autophagic flux, supporting its therapeutic potential for NAFLD. Additional research is needed to clarify the molecular mechanisms of quercetin and to determine the optimal dosing for clinical application.

Metabolic syndrome is a prevalent non-communicable disease characterized by central obesity, insulin resistance, hypertension, hyperglycemia, and hyperlipidemia. Epidemiological statistics indicate that one-third of the world's population is affected by metabolic syndrome. Unfortunately, owing to complicated pathogenesis and limited pharmacological options, the growing prevalence of metabolic syndrome threatens human health worldwide. Autophagy is an intracellular degradation mechanism that involves the degradation of unfolded or aggregated proteins and damaged cellular organelles, thereby maintaining metabolic homeostasis. Increasing evidence indicates that dysfunctional autophagy is closely associated with the development of metabolic syndrome, making it an attractive therapeutic target. Furthermore, a growing number of plant-derived polysaccharides have been shown to regulate autophagy, thereby alleviating metabolic syndrome, such as Astragalus polysaccharides, Laminaria japonica polysaccharides, Ganoderma lucidum polysaccharides and Lycium barbarum polysaccharides. In this review, we summarize recent advances in the discovery of autophagy modulators of plant polysaccharides for the treatment of metabolic syndrome, with the aim of providing precursor compounds for the development of new therapeutic agents. Additionally, we look forward to seeing more diseases being treated with plant polysaccharides by regulating autophagy, as well as the discovery of more intricate mechanisms that govern autophagy.

Autophagy is critical for energy homeostasis and the function of organelles such as endoplasmic reticulum (ER) and mitochondria. Dysregulated autophagy due to aging, environmental factors, or genetic predisposition can be an underlying cause of not only diabetes through β-cell dysfunction and metabolic inflammation, but also diabetic complications such as diabetic kidney diseases (DKDs). Dysfunction of lysosomes, effector organelles of autophagic degradation, due to metabolic stress or nutrients/metabolites accumulating in metabolic diseases is also emerging as a cause or aggravating element in diabetes and its complications. Here, we discuss the etiological role of dysregulated autophagy and lysosomal dysfunction in diabetes and a potential role of autophagy or lysosomal modulation as a new avenue for treatment of diabetes and its complications.

Nonalcoholic fatty liver disease (NAFLD) is reaching pandemic proportions due to overnutrition. The understanding of advanced stages that recapitulate the human pathology is of great importance to get a better mechanistic insight. We hypothesized that feeding of WT (C57BL) mice with a diet containing a high content of fat (21%), sugar (41.5%) and 1.25% of cholesterol (called from now on high fat, sucrose and cholesterol diet, HFSCD) will reproduce the characteristics of disease severity. Analysis of 16 weeks HFSCD-fed mice demonstrated increased liver weight and plasmatic liver damage markers compared with control diet (CD)-fed mice. HFSCD-fed mice developed greater hepatic triglyceride, cholesterol and NEFA content, inflammation and NAFLD activity score (NAS) indicating an advanced disease. HFSCD-fed mice displayed augmented hepatic total CD3+ T and Th9 lymphocytes, as well as reduced Th2 lymphocytes and CD206 anti-inflammatory macrophages. Moreover, T cells and anti-inflammatory macrophages correlated positively and inversely, respectively, with intrahepatic cholesterol content. Consistently, circulating cytotoxic CD8+ T lymphocytes, Th1, and B cell levels were elevated in HFSCD-fed WT mice. Hepatic and adipose tissue expression analysis demonstrated changes in fibrotic and metabolic genes related with cholesterol, triglycerides, and fatty acid synthesis in HFSCD-fed WT. These mice also exhibited reduced antioxidant capacity and autophagy and elevated ERK signaling pathway activation and CHOP levels. Our results indicate that the feeding with a cholesterol-enriched diet in WT mice produces an advanced NAFLD stage with fibrosis, characterized by deficient autophagy and ER stress along with inflammasome activation partially via ERK pathway activation.

Metabolic dysfunction-associated steatosis liver disease (MASLD) is one of the most common metabolic liver diseases around the world, whose prevalence continues to increase. Currently, there are few medications to treat MASLD. Ergothioneine is a natural compound derived from mushrooms whose sulfhydryl groups confer unique antioxidant, anti-inflammatory and detoxifying effects. Currently, research on the therapeutic effects of ergothioneine in MASLD is unknown. Therefore, this study explored the effect and mechanism of EGT in MASLD.

The ameliorative effects and mechanisms of ergothioneine on MASLD were evaluated using HFD mice and PA-treated AML12 cells. Mouse body weight, body fat, IPGTT, IPITT, immunohistochemistry, serum biochemical indices, and staining of liver sections were assayed to verify the protective role of ergothioneine in MASLD. RNA-seq was applied to explore the mechanism of action of ergothioneine. The role of ergothioneine in AML12 was confirmed by western blotting, qPCR, ELISA, Oil Red O staining, flow cytometry, and ROS assays. Subsequently, the 3-methyladenine (3-MA, an autophagy inhibitor) was subsequently used to confirm that ergothioneine alleviated MASLD by promoting autophagy.

Ergothioneine reduced body weight, body fat and blood lipids, and improved insulin resistance and lipid and glycogen deposition in MASLD mice. Furthermore, ergothioneine was found to increase autophagy levels and attenuate oxidative damage, inflammation, and apoptosis. In contrast, intervention with 3-MA abrogated these effects, suggesting that ergothioneine ameliorated effects by promoting autophagy.

Ergothioneine may be a drug with great therapeutic potential for MASLD. Furthermore, this protective effect was mediated through the activation of autophagy.

Sodium-dependent glucose cotransporter-2 (SGLT2) inhibitors, antidiabetic drugs that reduce blood sugar levels by inhibiting glucose reabsorption in the renal proximal tubules, also ameliorate nonalcoholic fatty liver disease (NAFLD). This study aimed to examine the effects of SGLT2 inhibition on hepatic steatosis and nonalcoholic steatohepatitis (NASH) using an in vitro model of NAFLD progression. HepG2 cells and a coculture of Hepa1c1c7 and Raw 264.7 cells were treated with 400 μM palmitic acid (PA), followed by treatment with or without 10 μM empagliflozin and dapagliflozin. In HepG2 cells, PA increased hepatic lipid accumulation, the expression of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β), exocytosis mediators (VAMP3 and SNAP23), and ER stress markers (GRP78, PERK, IRE1α, ATF6, ATF4, and CHOP), and the gene and protein expression of CD36. SGLT2 inhibitors reversed the effects of PA. SGLT2 inhibition via siRNA reduced proinflammatory-cytokine gene expression in thapsigargin-treated HepG2 cells. Transfection with CD36 siRNA reversed the elevated ATF4 and CHOP expression in PA-treated HepG2 cells. SGLT2 inhibition via an SGTL2 inhibitor and SGLT2 siRNA reduced CD36, Tnf-α, Il-6, Il-1β, Vamp2, Snap23, Atf4, and Chop expression in the PA-treated Hepa1c1c7-Raw 264.7 cell coculture and suppressed Tnf-α release in the Hepa1c1c7-Raw 264.7 cell coculture treated with lipopolysaccharide and PA. These findings indicate that SGLT2 inhibitors inhibited NAFLD progression by reducing hepatic lipid accumulation and inflammation.

Obesity is one of the world's major public health challenges. Its pathogenesis and comorbid metabolic disorders share common mechanisms, such as mitochondrial or endoplasmic reticulum dysfunction or oxidative stress, gut dysbiosis, chronic inflammation and altered autophagy. Numerous pro-autophagy dietary interventions are being investigated for their potential obesity-preventing or therapeutic effects. We summarize current data on the relationship between autophagy and obesity, and discuss various dietary interventions as regulators of autophagy-related genes in the prevention and ultimate treatment of obesity in humans, as available in scientific databases and published through July 2024. Lifestyle modifications (such as calorie restriction, intermittent fasting, physical exercise), including following a diet rich in flavonoids, antioxidants, specific fatty acids, specific amino acids and others, have shown a beneficial role in the induction of this process. The activation of autophagy through various nutritional interventions tends to elicit a consistent response, characterized by the induction of certain kinases (including AMPK, IKK, JNK1, TAK1, ULK1, and VPS34) or the suppression of others (like mTORC1), the deacetylation of proteins, and the alleviation of inhibitory interactions between BECN1 and members of the Bcl-2 family. Significant health/translational properties of many nutrients (nutraceuticals) can affect chronic disease risk through various mechanisms that include the activation or inhibition of autophagy. The role of nutritional intervention in the regulation of autophagy in obesity and its comorbidities is not yet clear, especially in obese individuals.

Metabolic dysfunction-associated fatty liver disease (MASLD) is a widespread liver disorder characterized by excessive fat accumulation in the liver, commonly associated with metabolic syndrome components such as obesity, diabetes, and dyslipidemia. With a global prevalence of up to 30%, MASLD is projected to affect over 100 million people in the U.S. and 20 million in Europe by 2030. The disease ranges from Steatotic Lived Disease (SLD) to more severe forms like metabolic dysfunction-associated steatohepatitis (MASH), which can progress to cirrhosis and hepatocellular carcinoma. Autophagy, a cellular process crucial for lipid metabolism and homeostasis, is often impaired in MASLD, leading to increased hepatic lipid accumulation and inflammation. Key autophagy-related proteins, such as Beclin1, LC3A, SQSTM1 (p62), CD36, and Perilipin 3, play significant roles in regulating this process. Disruption in these proteins contributes to the pathogenesis of MASLD. Quercetin, a natural polyphenolic flavonoid with antioxidant and anti-inflammatory properties, has promising results in mitigating MASLD. It may reduce hepatic lipid accumulation, improve mitochondrial function, and enhance autophagy. However, further research is needed to elucidate its mechanisms and validate its therapeutic potential in clinical settings. This underscores the need for continued investigation into autophagy and novel treatments for MASLD.

Autophagy is a lysosome-mediated self-degradation process of central importance for cellular quality control. It also provides macromolecule building blocks and substrates for energy metabolism during nutrient or energy deficiency, which are the main stimuli for autophagy induction. However, like most biological processes, autophagy itself requires ATP, and there is an energy threshold for its initiation and execution. We here present the first comprehensive review of this often-overlooked aspect of autophagy research. The studies in which ATP deficiency suppressed autophagy in vitro and in vivo were classified according to the energy pathway involved (oxidative phosphorylation or glycolysis). A mechanistic insight was provided by pinpointing the critical ATP-consuming autophagic events, including transcription/translation/interaction of autophagy-related molecules, autophagosome formation/elongation, autophagosome fusion with the lysosome, and lysosome acidification. The significance of energy-dependent fine-tuning of autophagic response for preserving the cell homeostasis, and potential implications for the therapy of cancer, autoimmunity, metabolic disorders, and neurodegeneration are discussed.

Liver transplantation has evolved into a mature clinical field, but scarcity of usable organs poses a unique challenge. Expanding the donor pool requires novel approaches for protecting hepatic physiology and cellular homeostasis. Here we define hepatocellular injury during transplantation, with an emphasis on modifiable cell death pathways as future therapeutics.

The adverse metabolic impacts of branched-chain amino acids (BCAA) have been elucidated are mediated by isoleucine and valine. Dietary restriction of isoleucine promotes metabolic health and increases lifespan. However, a high protein diet enriched in BCAA is presently the most useful therapeutic strategy for nonalcoholic fatty liver disease (NAFLD), yet, its underlying mechanism remains largely unknown. Fatty liver hemorrhagic syndrome (FLHS), a specialized laying hen NAFLD model, can spontaneously develop fatty liver and hepatic steatosis under a high-energy and high-protein dietary background that the pathogenesis of FLHS is similar to human NAFLD. The mechanism underlying dietary BCAA control of NAFLD development in laying hens remains unclear. Herein, we demonstrate that dietary supplementation with 67 % High BCAA has unique mitigative impacts on NAFLD in laying hens. A High BCAA diet alleviates NAFLD, by inhibiting the tryptophan-ILA-AHR axis and MAPK9-mediated de novo lipogenesis (DNL), promoting ketogenesis and energy metabolism, and activating PPAR-RXR and pexophagy to promote fatty acid β-oxidation. Furthermore, we uncover that High BCAA strongly activates ubiquitin-proteasome autophagy via downregulating UFMylation to trigger MAPK9-mediated DNL, fatty acid elongation and lipid droplet formation-related proteins ubiquitination degradation, activating PPAR-RXR and pexophagy mediated fatty acid β-oxidation and lipolysis. Together, our data highlight moderating intake of high BCAA by inhibiting the AHR/MAPK9 are promising new strategies in NAFLD and FLHS treatment.

Sub-optimal prenatal conditions such as maternal undernutrition during pregnancy and lactation posit high risks of adult metabolic diseases. High fructose intake causes insulin resistance and liver inflammation contributing to metabolic diseases. However, food-based preventive measure for these metabolic diseases in the offspring is under-researched. This study aims to investigate the effect of maternal broccoli powder (BP) intake during lactation on insulin resistance and liver inflammation in high-fructose-diet-fed adult male offspring exposed to maternal protein restriction.

Pregnant Wistar rats are provided normal protein (NP) or low protein (LP) diets and 0% or 0.74% BP-containing NP diets and 0% or 0.74% BP-containing LP diet during lactation. At weaning, offspring receiving water (W) or 10% fructose solution (Fr) are assigned into six groups: NP/NP/W, NP/NP/Fr, NP/NPBP/Fr, LP/LP/W, LP/LP/Fr, and LP/LPBP/Fr. At week 13, plasma insulin, macrophage infiltration, activated protein kinase (AMPK) and mechanistic target of rapamycin (mTOR) phosphorylation, and autophagy flux markers are examined. LP/LPBP/Fr shows lower insulin levels and Homeostatic model assessment for insulin resistance (HOMA-IR) values than LP/LP/Fr. Liver macrophage infiltration are decreased in LP/LPBP/Fr. LP/LPBP/Fr exhibits upregulated AMPK phosphorylation, downregulated mTOR phosphorylation, and increased Microtubule-associated protein1A/1B-light chain 3B-II (LC3B-II) levels.

Maternal BP intake during lactation ameliorates insulin resistance and inflammation in the livers of adult offspring on a high-fructose diet from LP mothers.

Cardiovascular disease (CVD) remains the major cause of morbidity and mortality around the world. Transcription factor EB (TFEB) is a master regulator of lysosome biogenesis and autophagy. Emerging studies revealed that TFEB also mediates cellular adaptation responses to various stimuli, such as mitochondrial dysfunction, pathogen infection and metabolic toxin. Based on its significant capability to modulate the autophagy-lysosome process (ALP), TFEB plays a critical role in the development of CVD. In this review, we briefly summarize that TFEB regulates cardiac dysfunction mainly through ameliorating lysosomal and mitochondrial dysfunction and reducing inflammation.

Recent studies have highlighted type 2 diabetes (T2DM) as a significant risk factor for the development of metabolic dysfunction-associated fatty liver disease (MAFLD). This investigation aimed to assess electroacupuncture's (EA) impact on liver morphology and function in T2DM rats, furnishing experimental substantiation for its potential to stall MAFLD progression in T2DM.

T2DM rats were induced by a high-fat diet and a single intraperitoneal injection of streptozotocin, and then randomly assigned to five groups: the T2DM group, the electroacupuncture group, the metformin group, combination group of electroacupuncture and metformin, combination group of electroacupuncture and Compound C. The control group received a standard diet alongside intraperitoneal citric acid - sodium citrate solution injections. After a 6-week intervention, the effects of each group on fasting blood glucose, lipids, liver function, morphology, lipid droplet infiltration, and fibrosis were evaluated. Techniques including Western blotting, qPCR, immunohistochemistry, and immunofluorescence were employed to gauge the expression of key molecules in AMPK-associated glycolipid metabolism, insulin signaling, autophagy, and fibrosis pathways. Additionally, transmission electron microscopy facilitated the observation of liver autophagy, lipid droplets, and fibrosis.

Our studies indicated that hyperglycemia, hyperlipidemia and IR promoted lipid accumulation, pathological and functional damage, and resulting in hepatic steatosis and fibrosis. Meanwhile, EA enhanced the activation of AMPK, which in turn improved glycolipid metabolism and autophagy through promoting the expression of PPARα/CPT1A and AMPK/mTOR pathway, inhibiting the expression of SREBP1c, PGC-1α/PCK2 and TGFβ1/Smad2/3 signaling pathway, ultimately exerting its effect on ameliorating hepatic steatosis and fibrosis in T2DM rats. The above effects of EA were consistent with metformin. The combination of EA and metformin had significant advantages in increasing hepatic AMPK expression, improving liver morphology, lipid droplet infiltration, fibrosis, and reducing serum ALT levels. In addition, the ameliorating effects of EA on the progression of MAFLD in T2DM rats were partly disrupted by Compound C, an inhibitor of AMPK.

EA upregulated hepatic AMPK expression, curtailing gluconeogenesis and lipogenesis while boosting fatty acid oxidation and autophagy levels. Consequently, it mitigated blood glucose, lipids, and insulin resistance in T2DM rats, thus impeding liver steatosis and fibrosis progression and retarding MAFLD advancement.