Hepatocyte Apoptosis Research Articles

4-Phenylbutyric acid suppresses psoralen-induced hepatotoxicity by inhibiting ERS and reestablishing mitochondrial fusion-fission balance in mice

Psoralen is a main active molecule of the traditional Chinese herb medicine Fructus Psoraleae. Our previous studies have shown that psoralen induced liver injury through the endoplasmic reticulum stress (ERS) signaling pathways. In this article, we studied whether the ERS inhibitor, 4-phenylbutyrate acid (4-PBA) could inhibit the liver toxicity caused by psoralen, and explored the underlying mechanisms. Mice were given the solvent, 20 mg/kg, 40 mg/kg, 80 mg/kg of psoralen, or 80 mg/kg of psoralen plus 4-PBA for 14 days. We found that 4-PBA significantly reduced the serum LDH and liver tissue MDA level, increased the activities of SOD and CAT, reduced liver weight and coefficient, repaired histopathological damage, and inhibited hepatocytes apoptosis induced by psoralen. RNA-seq transcriptomics found that except for the endoplasmic reticulum, the mitochondria was severely affected by psoralen. And genes involved in mitochondrial fusion, apoptosis, protein folding, and autophagy were found differently expressed in the psoralen group. Further studies found that 4-PBA inhibited the overexpression of GRP78 and CHOP, increased the Bcl-2/Bax ratio, and reduced the expression of Caspase-3. Moreover, 4-PBA reduced the overexpression of mitochondrial fission protein DRP1, increased the expression of fusion proteins Mfn-2 and OPA1, but has no inhibitory effects on autophagy proteins Atg5 or LC3A/B. In conclusion, 4-PBA inhibited ERS and reestablished mitochondrial fusion-fission balance, thereby blocking cell apoptosis, oxidative stress, and mitochondrial dysfunction, thus prevented against psoralen-induced hepatotoxicity.

Macrophage-Hepatocyte Circuits Mediated by Grancalcin Aggravate the Progression of Metabolic Dysfunction Associated Steatohepatitis.

The dynamic interplay between parenchymal hepatocytes and non-parenchymal cells (NPCs), such as macrophages, is an important mechanism for liver metabolic homeostasis. Although numerous endeavors have been made to identify the mediators of metabolic dysfunction associated steatohepatitis (MASH), the molecular underpinnings of MASH progression remain poorly understood, and therapies to arrest MASH progression remain elusive. Herein, it is revealed that the expression of grancalcin (GCA) is upregulated in the macrophages of patients and rodents with MASH and correlates with MASH progression. Notably, the administration of recombinant GCA aggravates the development of MASH, whereas, Gca deletion in myeloid cells blunts liver steatosis and inflammation in multiple MASH murine models. Mechanistically, GCA activates macrophages via TLR9-NF-κB signaling, and the activated macrophages promote hepatocyte lipid accumulation and apoptosis via secretion of Interleukin-6(IL-6), Tumor Necrosis Factor α (TNFα), and Interleukin-1β(IL-1β), thereby leading to hepatic steatosis and inflammation. Finally, the therapeutic administration of antibody blocking GCA effectively halts the progression of MASH. Collectively, these findings implicate GCA as a crucial mediator of MASH and clarify a new metabolic signaling axis between the hepatocytes and macrophages, implying that GCA can emerge as a particularly interesting putative therapeutic target for reversing MASH progression.

Glycidol-induced hepatocyte apoptosis via endoplasmic reticulum stress: The underlying role of the gut-liver axis

Glycidol (CAS: 556-52-5), a known carcinogen and genotoxicant, is often found in refined vegetable oils. Human exposure predominantly occurs through consumption of these oils and their byproducts, which contain glycidyl esters (GEs). Upon ingestion, GEs are metabolized to release glycidol, posing substantial health hazards. Historical studies have reported the tumorigenic properties of glycidol across various organs in mice models, encompassing the stomach, liver, lungs, brain, mammary gland, and skin. In this study, we employed a Balb/c mice model to investigate the hepatotoxic effects of glycidol following exposure to escalating doses (0, 25, 50, and 100 mg/kg bw/day). The hepatotoxicity was evidenced by a significant elevation in liver enzymes (ALT, AST), indicative of liver cell damage. Furthermore, biochemical analysis revealed heightened levels of oxidative stress indicators (SOD, MDA, GSH) and the upregulation of endoplasmic reticulum stress proteins, underscoring the cellular stress response. The induction of hepatocyte apoptosis served as a direct marker of liver damage caused by glycidol exposure. Additionally, glycidol altered the composition of intestinal microbiota and short-chain fatty acids (SCFAs), which unbalanced homeostasis. Gut barrier integrity markers (ZO-1, Claudin-1, Occludin, TLR4, LPS) indicated increased permeability of harmful substances to the liver via the gut-liver axis, which exacerbated hepatic injury. These findings highlight glycidol's disruption of gut homeostasis and its hepatotoxic potential.

HAF prevents hepatocyte apoptosis and progression to MASH and hepatocellular carcinoma through transcriptional regulation of the NF-κB pathway.

HCC incidence is increasing worldwide due to the obesity epidemic, which drives metabolic dysfunction-associated steatohepatitis (MASH) that can lead to HCC. However, the molecular pathways driving MASH-HCC are poorly understood. We have previously reported that male mice with haploinsufficiency of hypoxia-associated factor, HAF (SART1+/-) spontaneously develop MASH-HCC. However, the cell type(s) responsible for HCC associated with HAF loss are unclear. We generated SART1-floxed mice, which were crossed with mice expressing Cre-recombinase within hepatocytes (Alb-Cre; hepS-/-) or myeloid cells (LysM-Cre, macS-/-). HepS-/- mice (both male and female) developed HCC associated with profound inflammatory and lipid dysregulation suggesting that HAF protects against HCC primarily within hepatocytes. HAF-deficient hepatocytes showed decreased P-p65 and P-p50 and in many components of the NF-κB pathway, which was recapitulated using HAF siRNA in vitro. HAF depletion also triggered apoptosis, suggesting that HAF protects against HCC by suppressing hepatocyte apoptosis. We show that HAF regulates NF-κB activity by regulating transcription of TRADD and RIPK1. Mice fed a high-fat diet (HFD) showed marked suppression of HAF, P-p65 and TRADD within their livers after 26 weeks, but showed profound upregulation of these proteins after 40 weeks, implicating deregulation of the HAF-NF-κB axis in the progression to MASH. In humans, HAF was significantly decreased in livers with simple steatosis but significantly increased in HCC compared with normal liver. HAF is novel transcriptional regulator of the NF-κB pathway and is a key determinant of cell fate during progression to MASH and MASH-HCC.

Drug-induced oxidative stress actively prevents caspase activation and hepatocyte apoptosis

Cell death is a fundamental process in health and disease. Emerging research shows the existence of numerous distinct cell death modalities with similar and intertwined signaling pathways, but resulting in different cellular outcomes, raising the need to understand the decision-making steps during cell death signaling. Paracetamol (Acetaminophen, APAP)-induced hepatocyte death includes several apoptotic processes but eventually is executed by oncotic necrosis without any caspase activation. Here, we studied this paradoxical form of cell death and revealed that APAP not only fails to activate caspases but also strongly impedes their activation upon classical apoptosis induction, thereby shifting apoptosis to necrosis. While APAP intoxication results in massive drop in mitochondrial respiration, low cellular ATP levels could be excluded as an underlying cause of missing apoptosome formation and caspase activation. In contrast, we identified oxidative stress as a key factor in APAP-induced caspase inhibition. Importantly, caspase inhibition and the associated switch from apoptotic to necrotic cell death was reversible through the administration of antioxidants. Thus, exemplified by APAP-induced cell death, our study stresses that cellular redox status is a critical component in the decision-making between apoptotic and necrotic cell death, as it directly affects caspase activity.

Paeoniflorin protects hepatocytes from APAP-induced damage through launching autophagy via the MAPK/mTOR signaling pathway

BackgroundDrug-induced liver injury (DILI) is gradually becoming a common global problem that causes acute liver failure, especially in acute hepatic damage caused by acetaminophen (APAP). Paeoniflorin (PF) has a wide range of therapeutic effects to alleviate a variety of hepatic diseases. However, the relationship between them is still poorly investigated in current studies.PurposeThis work aimed to explore the protective effects of PF on APAP-induced hepatic damage and researched the potential molecular mechanisms.MethodsC57BL/6J male mice were injected with APAP to establish DILI model and were given PF for five consecutive days for treatment. Aiming to clarify the pharmacological effects, the molecular mechanisms of PF in APAP-induced DILI was elucidated by high-throughput and other techniques.ResultsThe results demonstrated that serum levels of ALP, γ-GT, AST, TBIL, and ALT were decreased in APAP mice by the preventive effects of PF. Moreover, PF notably alleviated hepatic tissue inflammation and edema. Meanwhile, the results of TUNEL staining and related apoptotic factors coincided with the results of transcriptomics, suggesting that PF inhibited hepatocyte apoptosis by regulated MAPK signaling. Besides, PF also acted on reactive oxygen species (ROS) to regulate the oxidative stress for recovery the damaged mitochondria. More importantly, transmission electron microscopy showed the generation of autophagosomes after PF treatment, and PF was also downregulated mTOR and upregulated the expression of autophagy markers such as ATG5, ATG7, and BECN1 at the mRNA level and LC3, p62, ATG5, and ATG7 at the protein level, implying that the process by which PF exerted its effects was accompanied by the occurrence of autophagy. In addition, combinined with molecular dynamics simulations and western blotting of MAPK, the results suggested p38 as a direct target for PF on APAP. Specifically, PF-activated autophagy through the downregulation of MAPK/mTOR signaling, which in turn reduced APAP injury.ConclusionsPaeoniflorin mitigated liver injury by activating autophagy to suppress oxidative stress and apoptosis via the MAPK/mTOR signaling pathway. Taken together, our findings elucidate the role and mechanism of paeoniflorin in DILI, which is expected to provide a new therapeutic strategy for the development of paeoniflorin.Graphical abstract

4-Methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP) exposure induces hepatotoxicity and nephrotoxicity - role of oxidative stress, mitochondrial dysfunction and pathways of cytotoxicity.

Bisphenol A (BPA) is a ubiquitous pollutant worldwide and 4-Methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP) is considered a major active metabolite of BPA with a wide range of potent toxicological properties. However, its adverse outcome pathway (AOP) on the hepatic and renal system has not yet been explored. Hence, the current study evaluated its effect on cell survival, oxidative stress, and apoptosis. In addition, the influence of signalling pathways on cytotoxicity and ROS generating enzymes (NOX2 and XO) on oxidative stress was explored by siRNA knockdown experiments. Further, its molecular interaction with SOD, CAT, and HSA (molecular docking and dynamics) was evaluated and validated with spectroscopy (fluorescence and FTIR) based methods. The outcome indicates that MBP exposure dose dependently increased the cytotoxic response, oxidative stress, and apoptosis in both hepatocytes and kidney cells. Further, MAPK signalling pathways and oxidative stress influenced the overall cytotoxic response in both cells. In addition, the stimulatory (NOX2 and XO) and inhibitory (SOD and CAT) effects of MBP were observed, along with a robust interaction with HSA. The overall observation illustrates that MBP exposure adversely impacts hepatic and renal cells through oxidative stress and relevant molecular pathways which may connect the missing links during risk assessment of BPA.

Polyribonucleotide nucleotidyltransferase 1 participates in metabolic-associated fatty liver disease pathogenesis by affecting lipid metabolism and mitochondrial homeostasis

ObjectiveMetabolic-associated fatty liver disease (MAFLD) represents one of the most prevalent chronic liver conditions worldwide, but its precise pathogenesis remains unclear. This research endeavors to elucidate the involvement and molecular mechanisms of polyribonucleotide nucleotidyltransferase 1 (PNPT1) in the progression of MAFLD. MethodsThe study employed western blot and qRT-PCR to evaluate PNPT1 levels in liver specimens from individuals diagnosed with MAFLD and in mouse models subjected to a high-fat diet. Cellular studies investigated the effects of PNPT1 on lipid metabolism, apoptosis, and mitochondrial stability in hepatocytes. Immunofluorescence was utilized to track the subcellular movement of PNPT1 under high lipid conditions. RNA immunoprecipitation and functional assays were conducted to identify interactions between PNPT1 and Mcl-1 mRNA. The role of PPARα as an upstream transcriptional regulator of PNPT1 was investigated. Recombinant adenoviral vectors were utilized to modulate PNPT1 expression in vivo. ResultsPNPT1 was found to be markedly reduced in liver tissues from MAFLD patients and HFD mice. In vitro, PNPT1 directly regulated hepatic lipid metabolism, apoptosis, and mitochondrial stability. Under conditions of elevated lipids, PNPT1 relocated from mitochondria to cytoplasm, modifying its physiological functions. RNA immunoprecipitation revealed that the KH and S1 domains of PNPT1 bind to and degrade Mcl-1 mRNA, which in turn affects mitochondrial permeability. The transcriptional regulator PPARα was identified as a significant influencer of PNPT1, impacting both its expression and subsequent cellular functions. Alterations in PNPT1 expression were directly correlated with the progression of MAFLD in mice. ConclusionsThe study confirms the pivotal function of PNPT1 in the development of MAFLD through its interactions with Mcl-1 and its regulatory effects on lipid metabolism and mitochondrial stability. These insights highlight the intricate association between PNPT1 and MAFLD, shedding light on its molecular pathways and presenting a potential new therapeutic avenue for MAFLD management.

Laurus nobilis L. leaves Suppress Alcohol-Related Liver Disease by Exhibiting Antioxidant and Anti-Inflammatory Effects in Alcohol-Treated Hepatocytes and Mice.

Excessive and prolonged alcohol consumption can lead to a serious health condition known as alcohol-related liver disease (ARLD). This ailment represents a significant worldwide health challenge, affecting populations across various demographics. ARLD has a multifactorial pathogenesis involving oxidative stress, inflammation, dysregulated lipid metabolism, and apoptosis. In this study, we investigated the hepatoprotective effects of Laurus nobilis L. leaf water extract (LLE) against ARLD in alcohol-treated hepatocytes and mice. LLE exhibited antioxidant and anti-inflammatory properties by enhancing antioxidant enzyme activities and suppressing proinflammatory cytokines and CYP2E1 expression in ethanol-treated hepatocytes. Moreover, LLE mitigated lipogenesis by modulating the expression of lipogenic factors in ethanol-treated hepatocytes. In vivo, LLE administration attenuated liver injury, oxidative stress, inflammation, and lipid accumulation induced by alcohol consumption in mice. Additionally, LLE suppressed apoptosis signaling pathways implicated in alcohol-induced hepatocyte apoptosis. These findings suggest that LLE functions as a multifaceted therapeutic agent for ARLD by modulating multiple cellular mechanisms, including the reduction of oxidative damage, mitigation of inflammatory responses, alleviation of lipid-mediated toxicity, and regulation of programmed cell death pathways.

Histomorphological and Dynamical Changes in Female River Lampreys during Maturation under Controlled Conditions as a Part of Lamprey Restoration Programs.

More than 40 species of lampreys (Petromyzontiformes) are known worldwide. Some of them are parasitic and feed on the blood of fish or other aquatic animals. Lampreys spawn once in their lifetime, after which they die. One of the representatives of the ichthyofauna of European rivers is the river lamprey, Lampetra fluviatilis. The river lamprey is now an endangered species due to loss and degradation of their habitats. The present study investigated gonadal development without hormonal stimulation in female river lampreys during puberty under controlled conditions for a period of seven months. Female river lampreys were kept in conditions that mimicked the natural environment. During the November-May period, samples were taken monthly to determine the extent of gonadal development and gastrointestinal and liver changes using histological examination. From the results obtained, the dynamical changes were determined for the following: gonadosomatic index (GSI; %), hepatosomatic index (his; %), and digestivesomatic index (DSI; %). With the gonadal development of female lampreys, an increase in GSI (7-23%; November-May) and a decrease in DSI (0.4-0.1%; November-May) histological changes were observed in the gonads (oocyte development), intestines (over time, decreased lipid vacuoles and enterocyte apoptosis), and in the liver (decreased lipid vacuoles and hepatocyte apoptosis over time) and in the digestive system resulting from its degradation. Also, it was observed that there was a change in the color of the liver to green in April. This study demonstrated the key role of the liver in the oocyte maturation process in this species.

Euphorbia milii and propolis combination tea reduced hepatic steatosis and hepatocyte apoptosis in high-fat diet rat model

Background: Dyslipidemia can cause various organ disorders, such as fatty liver disease. Over time, fatty liver disease has become more commonplace worldwide and may cause mortality if the progression worsens. Natural components from Euphorbia milii (E. milii) and propolis (EMP) have been demonstrated as immunomodulators that reduce total cholesterol levels.Objective: To prove the effect of EMP tea on inhibiting fatty liver and hepatocyte apoptosis in high-fat diet (HFD)-induced rats.Methods: This study applied a post-test-only control group design using 18 Wistar rats, which were divided into three groups: K0 (received standard feed), KN (received HFD of 2 g/200 g Body weight (BW) in a day), and P (received HFD of 2 g/200 g BW in a day and EMP of tea 40 mg/100 g BW in a day). The interventions were conducted for 30 days, followed by termination on day 31 for liver tissue collection and analysis. We calculated the hepatic steatosis with the help of hematoxylin-eosin (HE) staining. Hepatocyte apoptosis was also determined with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining.Results: The K0 group had a lower hepatic steatosis percentage (17.87 ± 1.81) than KN (63.75 ± 15.88). We also found no hepatocyte apoptosis in the K0 but a high hepatocyte apoptosis index in the KN (3.98 ± 0.29). The combination of EMP tea in HFD-induced rats significantly reduced hepatic steatosis and apoptosis percentage (25.33 ± 1.17 and 0.91 ± 0.61, respectively). Conclusion: We demonstrated that combining EMP tea reduced hepatic steatosis and hepatocyte apoptotic index in HFD-induced rats, suggesting its potential as a treatment for these conditions.

Exercise-activated hepatic autophagy combined with silymarin is associated with suppression of apoptosis in rats subjected to dexamethasone induced- fatty liver damage.

There is a need for effective treatments for non-alcoholic fatty liver disease (NAFLD) that are economically inexpensive, and have few side effects. The present study aimed to investigate exercise training and silymarin on hepatocyte death factors in rats with liver damage. Forty-nine male Wistar rats were assigned to seven groups: sedentary control, fatty liver control (DEX), fatty liver + high-intensity interval training (HIIT), fatty liver + HIIT + silymarin (HIIT + SILY), fatty liver + continuous training (CT), fatty liver + CT + silymarin (CT + SILY), and fatty liver + silymarin (SILY). A subcutaneous injection of dexamethasone for 7 days was used to induce fatty liver in rats. Masson's trichrome and hematoxylin-eosin staining were done to evaluate hepatic injury. The hepatocyte apoptosis was determined by TUNEL assay. Real-Time PCR was conducted to evaluate the gene expressions of caspase-9, adenosine monophosphate-activated protein kinase (AMPKα1), mitofusin 2 (Mfn2), and damage-regulated autophagy modulator (DRAM). Liver tissue changes and serum levels of liver enzymes were also evaluated. Liver apoptosis was decreased in the CT, HIIT, HIIT + SILY and CT + SILY groups compared to the DEX group. Both continuous and high-intensity training models produced beneficial alterations in liver morphology and hepatic injuries that were significant in exercise training + silymarin group. This impact was accompanied by increased AMPKα1 and DRAM gene expression and decreased caspase-9 and Mfn2 gene expression. Liver enzyme levels were high in the DEX group and treatment with silymarin significantly reduced it. Silymarin supplementation combined with interval or continuous training substantially improves DEX-induced hepatic steatosis and hepatocyte injury mostly through suppressing liver apoptosis and upregulating autophagy, which may provide a novel perspective for NAFLD treatment.

Radix Rehmanniae Praeparata extracts ameliorate hepatic ischemia-reperfusion injury by restoring lipid metabolism in hepatocytes

Ethnopharmacological relevanceHepatic ischemia/reperfusion injury (HIRI) is a common occurrence during or after liver surgery, representing a major cause for postoperative complications or increased morbidity and mortality in liver diseases. Rehmanniae Radix Praeparata (RRP) is a traditional Chinese medicine frequently used and has garnered extensive attention for its therapeutic potential treating cardiovascular and hepatic ailments. Recent studies have indicated the possibility of RRP in regulating lipid accumulation and apoptosis in hepatocytes. Aim of the studyThis study aimed to investigate the specific mechanisms by which RRP may impede the progression of HIRI through the regulation of lipid metabolism. Materials and methodsHigh-performance liquid chromatography (HPLC) was used to identify the major components of RRP water extract. C57BL/6J mice were orally given RRP at doses of 2.5 g/kg, 5 g/kg, and 10 g/kg for a duration of 7 days before undergoing HIRI surgery. Furthermore, we established a lipid-loaded in vitro model by exposing hepatocytes to oleic acid and palmitic acid (OAPA). The anti-HIRI effect of RRP was determined through transcriptomics and various molecular biology experiments. ResultsAfter identifying active ingredients in RRP, we observed that RRP exerted lipid-lowering and hepatoprotective effects on HIRI mice and OAPA-treated hepatocytes. RRP activated AMP-activated protein kinase (AMPK) and inhibited mammalian target of rapamycin (mTOR), which further on the one hand, inhibited the cleavage and activation of sterol regulatory element binding protein 2 (SREBP2) by limiting the movement of SREBPs cleavage-activating protein (SCAP)-SREBP2 complex with the help of endoplasmic reticulum lipid raft-associated protein 1 (ERLIN1) and insulin-induced gene 1 (INSIG1), and on the other hand, promoted liver X receptor α (LXRα) nuclear transportation and subsequent cholesterol efflux. Meanwhile, the anti-lipotoxic effect of RRP can be partly reversed by an LXRα inhibitor but largely blocked by the application of compound C, an AMPK inhibitor. ConclusionOur study elucidated that RRP served as a potential AMPK activator to alleviate HIRI by blocking SREBP2 activation and cholesterol synthesis, while also activating LXRα to facilitate cholesterol efflux. These findings shed new light on the potential therapeutic use of RRP for improving HIRI.

Chromium Affects Mitochondrial Function, Leading to Apoptosis and Autophagy in Turtle Primary Hepatocytes.

Hexavalent chromium (Cr(VI)), a pervasive industrial contaminant, is highly toxic to both humans and animals. However, its effects on turtles are largely unexplored. Our study aimed to investigate the toxic effects of Cr(VI) on the Reeves' turtles (Mauremys reevesii) primary hepatocytes. We exposed hepatocytes to two concentrations (25 μM and 50 μM) of Cr(VI) for 24 h. The results showed that compared to controls, Cr(VI)-treated cells showed elevated antioxidant enzyme activity (catalase (CAT) and superoxide dismutase (SOD)) and increased reactive oxygen species (ROS) levels. Adenosine triphosphatae (ATP) levels decreased, indicating mitochondrial dysfunction. Additionally, we found significant changes in mitochondrial dynamics related genes, with downregulation of mitofusin 2 (Mfn2) and silent information regulator 1 (SIRT1) and a decrease in sirtuin 3 (SIRT3) and tumor protein 53 (p53) mRNA levels. Annexin V-FITC fluorescence staining-positive cells increased with higher Cr(VI) concentrations, marked by elevated bcl-2-associated X protein (Bax) and cysteinyl aspartate specific proteinase (Caspase3) mRNA levels and reduced B-cell lymphoma-2 (Bcl2) expression. Autophagy-related genes were also affected, with increased microtubule-associated protein 1 light chain 3 (LC3-I), microtubule-associated protein light chain 3II (LC3-II), unc-51-like autophagy-activating kinase 1 (ULK1), and sequestosome 1 (p62/SQSTM1) mRNA levels and decreased mammalian target of rapamycin (mTOR) and Beclin1 expression. Taken together, Cr(VI) promotes cell apoptosis and autophagy in turtle hepatocytes by inducing oxidative stress and disrupting mitochondrial function. These findings highlight the serious health risks posed by Cr(VI) pollution and emphasize the need for protecting wild turtle populations.

Fanlian Huazhuo Formula alleviates high-fat diet-induced non-alcoholic fatty liver disease by modulating autophagy and lipid synthesis signaling pathway.

Fanlian Huazhuo Formula (FLHZF) has the functions of invigorating spleen and resolving phlegm, clearing heat and purging turbidity. It has been identified to have therapeutic effects on type 2 diabetes mellitus (T2DM) in clinical application. Non-alcoholic fatty liver disease (NAFLD) is frequently diagnosed in patients with T2DM. However, the therapeutic potential of FLHZF on NAFLD and the underlying mechanisms need further investigation. To elucidate the effects of FLHZF on NAFLD and explore the underlying hepatoprotective mechanisms in vivo and in vitro. HepG2 cells were treated with free fatty acid for 24 hours to induce lipid accumulation cell model. Subsequently, experiments were conducted with the different concentrations of freeze-dried powder of FLHZF for 24 hours. C57BL/6 mice were fed a high-fat diet for 8-week to establish a mouse model of NAFLD, and then treated with the different concentrations of FLHZF for 10 weeks. FLHZF had therapeutic potential against lipid accumulation and abnormal changes in biochemical indicators in vivo and in vitro. Further experiments verified that FLHZF alleviated abnormal lipid metabolism might by reducing oxidative stress, regulating the AMPKα/SREBP-1C signaling pathway, activating autophagy, and inhibiting hepatocyte apoptosis. FLHZF alleviates abnormal lipid metabolism in NAFLD models by regulating reactive oxygen species, autophagy, apoptosis, and lipid synthesis signaling pathways, indicating its potential for clinical application in NAFLD.

A novel mouse model of hepatocyte-specific apoptosis-induced myeloid cell-dominant sterile liver injury and repair response.

Apoptosis, inflammation, and wound healing are critical pathophysiological events associated with various liver diseases. Currently, there is a lack of in vivo approaches to study hepatocyte apoptosis-induced liver injury and repair. To address this critical knowledge gap, we developed a unique genetically modified mouse model, namely, 3-Transgene (Tg) with inducible Hepatocyte-Specific Apoptosis Phenotype (3xTg-iHAP) in this study. The 3xTg-iHAP mice possess three transgenes including Alb-Cre, Rosa26-rtTA, and tetO-Fasl on a B6 background. These mice are phenotypically normal, viable, and fertile. After subcutaneous administration of a single dose of doxycycline (5 mg/kg, Dox) to 3xTg-iHAP mice, we observed a complete histological spectrum of sterile liver wound-healing responses: asymptomatic hepatocyte apoptosis at 8 h, necrotic liver injury and sterile inflammation at 48 h, followed by hepatocyte mitosis and regeneration within 7 days. During the injury phase, the mice exhibited an increase in the biomarkers of alanine aminotransferase (ALT), chemokine (C-X-C motif) ligand 1 (CXCL1), and IL-6 in peripheral blood, as well as α-smooth muscle actin (α-SMA) protein in liver tissues. Conversely, the mice displayed a decrease in these markers in the recovery phase. Remarkably, this model shows that the sterile liver injury following elevated hepatocyte apoptosis is associated with an increase in myeloid cells in the liver. Within 7 days post-Dox administration, the liver of Dox-treated 3xTg-iHAP mice displays a normal histological structure, indicating the completion of wound healing. Together, we established a novel mouse model of injury and regeneration induced by hepatocyte apoptosis. This tool provides a robust in vivo platform for studying the pathophysiology of sterile liver inflammation, regeneration, and new therapeutic interventions for liver diseases.NEW & NOTEWORTHY Bu et al. present a triple-transgenic mouse model, namely, 3xTg-iHAP mice that are engineered to explore hepatocyte apoptosis-triggered sterile liver injury and regeneration. This model demonstrates a full spectrum of liver wound-healing responses from asymptomatic apoptosis to injury, myeloid cell-dominant sterile inflammation, and repair after induction of hepatocyte-specific apoptosis. The robust nature of this model makes it an invaluable in vivo tool for studying sterile liver inflammation, regeneration, and new therapeutic strategies.

Co-exposure of polyvinyl chloride microplastics with cadmium promotes nonalcoholic fatty liver disease in female ducks through oxidative stress and glycolipid accumulation

A recently discovered environmental contaminant, microplastics (MPs) are capable of amassing within the body and pose a grave threat to the health of both humans and animals. It is widely acknowledged that the combination of cadmium (Cd), a hazardous heavy metal, and microplastics produces synergistic deleterious effects. Nevertheless, the mechanism by which co-exposure to polyvinyl chloride microplastics (PVC-MPs) and Cd damages the liver of avian females is unknown. Globally prevalent and the subject of extensive research in mammals, non-alcoholic fatty liver disease (NAFLD) is a chronic liver condition. However, the mechanisms underlying injury to the avian digestive system caused by NAFLD remain unknown. Two months of co-exposure to Cd and PVC-MPs, pure water, solitary Cd exposure, single microplastics exposure, and pure water were administered to female Muscovy ducks in this study. The objective of this research was to examine whether the co-exposure of duck liver to PVC-MPs and Cd-induced oxidative stress resulted in NAFLD and subsequent apoptosis of hepatic cells. The study's findings showed that hepatocyte shape and functional activity were negatively impacted by PVC-MP and Cd buildup in liver tissues. Reduced liver organ coefficients, increased alanine aminotransferase (ALT) content, and ultrastructural damage to hepatocyte nuclei and mitochondria are indicators of this. These results point to a possible impairment in liver function. phosphoenolpyruvate carboxykinase 1 (PCK1) deficiency activates the protein kinase B/phosphatidylinositol 3-kinase (PI3K/AKT) pathway in the livers of female reproductive ducks that have been damaged by oxidative stress. This stimulation induces lipid deposition, fibrosis, and glycogen accumulation, which ultimately results in hepatocyte apoptosis. In summary, our research provides evidence that PVC-MPs cause oxidative harm to the liver, which subsequently results in fibrosis of liver tissue, hepatic glucolipid metabolism, and ultimately apoptosis.

Enhanced In Vitro Recapitulation of In Vivo Liver Regeneration by Co-Culturing Hepatocyte Organoids with Adipose-Derived Mesenchymal Stem Cells, Alleviating Steatosis and Apoptosis in Acute Alcoholic Liver Injury.

Hepatocyte organoids (HOs) have superior hepatic functions to cholangiocyte-derived organoids but suffer from shorter lifespans. To counteract this, we co-cultured pig HOs with adipose-derived mesenchymal stem cells (A-MSCs) and performed transcriptome analysis. The results revealed that A-MSCs enhanced the collagen synthesis pathways, which are crucial for maintaining the three-dimensional structure and extracellular matrix synthesis of the organoids. A-MSCs also increased the expression of liver progenitor cell markers (KRT7, SPP1, LGR5+, and TERT). To explore HOs as a liver disease model, we exposed them to alcohol to create an alcoholic liver injury (ALI) model. The co-culture of HOs with A-MSCs inhibited the apoptosis of hepatocytes and reduced lipid accumulation of HOs. Furthermore, varying ethanol concentrations (0-400 mM) and single-versus-daily exposure to HOs showed that daily exposure significantly increased the level of PLIN2, a lipid storage marker, while decreasing CYP2E1 and increasing CYP1A2 levels, suggesting that CYP1A2 may play a critical role in alcohol detoxification during short-term exposure. Moreover, daily alcohol exposure led to excessive lipid accumulation and nuclear fragmentation in HOs cultured alone. These findings indicate that HOs mimic in vivo liver regeneration, establishing them as a valuable model for studying liver diseases, such as ALI.

Modeling hepatocyte apoptosis in chronic HCV infection with impulsive drug control

Chronic hepatitis C virus (HCV) infection is one of the leading life-threatening diseases owing to its non-cytopathic nature and scarcity of vaccines to combat. Hepatocyte apoptosis casts extensive impact in regulating chronic HCV infection. We propose a four dimensional deterministic model scheming the role of hepatocyte apoptosis and significance of HCV-specific CTL response in the intermediate stages of chronic HCV infection. Numerical simulation indicates that unregulated behavior of hepatocyte apoptosis triggers hepatocellular carcinoma and prolonged continuation of apoptosis induces liver damages. The system undergoes backward bifurcation and the value of the basic reproduction number R0=0.98<1 shows recurrence of infection. Local sensitivity analysis has been performed to reveal the most sensitive parameters responsible for the progression and mitigation of infection. In order to control of chronic HCV infection through pan-genotypic direct acting antiviral drugs (DAAs), impulsive differential equations are considered to study the effect of perfect drug adherence to both fixed and non-fixed dosing. For possible eradication of the chronic HCV infection, impulsive drug control suggests significant viral load reduction. The analytical results obtained for both non-impulsive and impulsive models are quantified biologically.

Semaglutide Ameliorates Hepatocyte Steatosis in a Cell Co-Culture System by Downregulating the IRE1α-XBP1-C/EBPα Signaling Pathway in Macrophages.

Non-alcoholic fatty liver disease (NAFLD) is currently the most common type of chronic liver disease. Semaglutide is a glucose-lowering drug administered for the treatment of type 2 diabetes mellitus (T2DM) and is clinically effective in the treatment of NAFLD. X-box binding protein 1 (XBP1) is related to the pathogenesis of both NAFLD and T2DM. The aim of the present study was to demonstrate whether the underlying mechanism of semaglutide treatment for NAFLD is via downregulation of the inositol-requiring transmembrane kinase/endonuclease-1α (IRE1α)-XBP1-CCAAT/enhancer binding protein α (C/EBPα) signaling pathway in macrophages. In the present study, NAFLD cell modeling was induced by oleic acid (0.4 m<sc>m</sc>) and palmitic acid (0.2 m<sc>m</sc>). Hepatocytes (AML12) and macrophages (RAW264.7) were co-cultured in 6-well Transwell plates. Semaglutide (60 or 140 n<sc>m</sc>) was administrated for 24 h, while pioglitazone (2 μ<sc>m</sc>) and toyocamycin (200 n<sc>m</sc>) were used as a positive control drug and a XBP1 inhibitor, respectively. Autophagy and apoptosis of AML12 cells were detected by transmission electron microscopy and Western blotting (WB). Hepatocyte steatosis was evaluated by adopting total intracellular triglyceride determination, analysis of the relative expression of proteins and genes associated with lipid metabolism and hepatocyte Oil red O staining. Detection of inflammation factors was conducted by ELISA and WB. To explore the underlying mechanism of NAFLD treatment with semaglutide, the relative expression of related proteins and genes were tested. Our study demonstrated that semaglutide treatment improved autophagy and inhibited apoptosis of hepatocytes, while notably ameliorating steatosis of hepatocytes. In addition, inflammation was attenuated in the NAFLD cell co-culture model after semaglutide administration. Semaglutide also significantly reduced the protein and gene expression levels of the IRE1α-XBP1-C/EBPα signaling pathway in macrophages. Semaglutide partially ameliorated NAFLD by downregulating the IRE1α-XBP1-C/EBPα signaling pathway in macrophages. These findings may provide a potential theoretical basis for semaglutide therapy for NAFLD.