Liver Injury Research Articles

Secondary Syphilis Can Simultaneously Mimic Cholestatic Liver Injury and Glomerular Nephropathy

ABSTRACT Syphilis, a disease affecting millions, still poses challenges for men who have sex with men in high-income countries and often presents in varying ways. It is exceedingly rare for syphilis to simultaneously cause an acute liver injury and nephropathy. This case describes the concomitant clinical presentation of these abnormalities and also describes a liver injury that mimicked cholestatic disease. Treatment of syphilis led to complete resolution of the liver and kidney injury. This case demonstrates a need to exclude syphilis in patients with high-risk behaviors who present with cholestatic liver injury in atypical fashions.

Liver Injury in People With HIV on Antituberculosis and/or Antiretroviral Therapy-Assessing Causality Using the Updated Roussel Uclaf Causality Assessment Method.

We compared performance of the Roussel Uclaf Causality Assessment Method (RUCAM) with multidisciplinary expert panel review in identifying a drug-induced liver injury (DILI) due to antituberculosis therapy (ATT) and/or antiretroviral therapy (ART). Cases were drawn from a prospective registry of hospitalised adults with suspected DILI due to ATT and/or ART in Cape Town, South Africa. Participants had to fulfil American Thoracic Society criteria for ATT interruption (alanine transaminase [ALT] ≥5 times upper limit of normal [ULN]/ALT ≥3 times [ULN] and symptomatic). Causality assessment by expert panel review served as reference standard. The panel ranked potentially implicated drugs as certain, probable, possible or unlikely causes guided by World Health Organization Uppsala Monitoring Centre criteria. The RUCAM was performed for each potentially implicated drug. We calculated sensitivity and specificity of the RUCAM in identifying a probable/certain drug cause for liver injury. We included 48 participants. All were people with HIV (PWH). Twenty-seven were on concomitant ART and ATT, with a median of six potentially hepatotoxic drugs per case. Sensitivity and specificity of the RUCAM in identifying a probable/certain drug cause of liver injury compared with expert panel review was 7% and 100% respectively. Implicated drugs (times ranked probable/certain by panel) were isoniazid (18/0), pyrazinamide (17/0), rifampicin (15/1), efavirenz (6/4) and lopinavir/ritonavir (1/0). PWH with liver injury received multiple potentially implicated drugs, which may increase liver injury risk and complicate causality assessment. Compared with expert panel review, the RUCAM had low sensitivity in detecting probable or certain drug causes of liver injury.

Auricularia auricula polysaccharide alleviates cyclophosphamide-induced liver injury in mice involving remodeling of the gut bacteriome, mycobiome, and metabolome

In this study, a novel polysaccharide (AHP) from Auricularia auricula was isolated and purified, showing protective effects against CTX-induced liver injury in mice. To study the action mechanism of AHP, a liver injury model was established by intraperitoneally injection 80 mg/kg of CTX for 3 consecutive days. The focus was on how AHP regulated the gut bacteriome and mycobiome to help alleviate metabolic disorders associated with liver injury. Results showed that AHP amended liver injury by improving liver function, stabilizing oxidative stress homeostasis, reducing inflammatory invasion and activating Akt/GSK3β/Nrf-2/HO-1 signaling pathway. The 16S ribosomal DNA (16S rDNA) and Internal Transcribed Spacer-1 (ITS1) sequencing results demonstrated that AHP supplementation significantly restored the gut bacteriome and mycobiome composition in CTX-induced liver injury mice, by enriching the abundance of beneficial bacteriome (unclassified_Muribaculaceae, Faecalibaculum and Alloprevotella) and mycobiome (Fusarium), reducing the abundance of harmful bacteriome (Akkermanisa) and mycobiome (Fusicolla and Cladosporium). Analysis of untargeted metabolomics indicated that AHP altered the levels of metabolites associated with both bile acid and arachidonic acid metabolism, showing a significant connection to the AHP-regulated bacteriome and mycobiome. To conclude, the findings suggested that AHP was a viable and secure candidate for use as a hepatoprotective medication.

Gut-Liver Axis: Modulating the Gut Microbiota and Its Metabolic Products as a Potential Therapeutic Strategy for the Treatment of Hepatic Ischemia-Reperfusion Injury.

Hepatic ischemia-reperfusion injury (HIRI) is a major complication reported in various clinical scenarios such as liver transplantation (LTx), hepatectomy, and acute hepatic insult. This condition affects the restoration of hepatic functionalities post-LTx. Contemporary scientific inquiries have highlighted the involvement of intestinal microbiota and their metabolic by-products in the initiation and progression of HIRI. Perturbations in the gut microbiome, instigated by external stressors such as inflammatory processes, ischemic conditions, and reperfusion events, affect the biosynthesis of metabolites such as short-chain fatty acids (SCFAs), bile acids (BAs), and lipopolysaccharides (LPS). SCFAs can exert anti-inflammatory effects, modulate cellular apoptosis, and attenuate oxidative stress, thereby ameliorating hepatic injury. Other studies have shown that the intestinal microbiota confers hepatoprotective effects by modulating the host's immune response and synthesis of cytokines, controlling inflammation, and enhancing liver protection. This review comprehensively describes the mechanisms underlying the association of gut microbiota and its metabolites with hepatic disease and ischemia-reperfusion injury. The findings from recent studies investigating the gut-liver axis are reviewed to identify therapeutic avenues for the prevention and treatment of liver dysfunction and ischemia-reperfusion injury. In-so-doing, novel pathways and perspectives can be exploited to develop therapies for the control of inflammatory hepatic ischemia-reperfusion injury, particularly following liver transplantation or surgical intervention.

Sensing steroid hormone 17α-hydroxypregnenolone by GPR56 enables protection from ferroptosis-induced liver injury.

G protein-coupled receptors (GPCRs) mediate most cellular responses to hormones, neurotransmitters, and environmental stimulants. However, whether GPCRs participate in tissue homeostasis through ferroptosis remains unclear. Here we identify that GPR56/ADGRG1 renders cells resistant to ferroptosis and deficiency of GPR56 exacerbates ferroptosis-mediated liver injury induced by doxorubicin (DOX) or ischemia-reperfusion (IR). Mechanistically, GPR56 decreases the abundance of phospholipids containing free polyunsaturated fatty acids (PUFAs) by promoting endocytosis-lysosomal degradation of CD36. By screening a panel of steroid hormones, we identified that 17α-hydroxypregnenolone (17-OH PREG) acts as an agonist of GPR56 to antagonize ferroptosis and efficiently attenuates liver injury before or after insult. Moreover, disease-associated GPR56 mutants were unresponsive to 17-OH PREG activation and insufficient to defend against ferroptosis. Together, our findings uncover that 17-OH PREG-GPR56 axis-mediated signal transduction works as a new anti-ferroptotic pathway to maintain liver homeostasis, providing novel insights into the potential therapy for liver injury.

Hepatic bile acid accretion correlates with cholestatic liver injury and therapeutic response in Cyp2c70 knockout mice with a humanized bile acid composition.

Cyp2c70 knockout (KO) mice lack the liver enzyme responsible for synthesis of 6-hydroxylated muricholate bile acid species and possess a more hydrophobic human-like bile acid composition. Cyp2c70 KO mice develop cholestatic liver injury that can be prevented by administration of an ileal bile acid transporter (IBAT) inhibitor. In this study, we investigated the potential of an ileal bile acid transporter (IBAT) inhibitor (SC-435) and steroidal FXR agonist (cilofexor) to modulate established hepatobiliary injury and the consequent relationship of intrahepatic bile acid content and hydrophobicity to the cholestatic liver injury phenotype. Oral administration of SC-435, cilofexor, or combined treatment for 2 weeks markedly reduced serum markers of liver injury and improved histological and gene expression markers of fibrosis, liver inflammation, and ductular reaction in male and female Cyp2c70 KO mice, with greatest benefit in the combination treatment group. The IBAT inhibitor and FXR agonist significantly reduced intrahepatic bile acid content but not hepatic bile acid pool hydrophobicity, and markers of liver injury were strongly correlated with intrahepatic total bile acid and taurochenodeoxycholic acid accretion. Biomarkers of liver injury increased linearly with similar hepatic thresholds for pathological accretion of hydrophobic bile acids in male and female Cyp2c70 KO mice. These findings further support targeting intrahepatic bile acid retention as a component of treatments for cholestatic liver disease.

Exploring the Mechanism of Action of Sericin in Ameliorating non-Alcoholic Fatty Liver Disease in Mice Based on the Nrf2- GPX4/ NF-κB p65 Pathway

Objective: To explore the ameliorative effect and mechanism of action of sericin on liver injury in Non-Alcoholic Fatty Liver Disease (NAFLD) model mice. Methods: Mice were fed a high-fat diet for 8 weeks to establish NAFLD model mice. The NAFLD mice were then randomly divided into 6 groups and given 0, 250, 500, and 1000 mg/kg body weight of sericin, 1000 mg/kg sericin + ML385 (a protein inhibitor of Nrf2), and Zhibitai Capsules (a positive drug), by gavage, respectively. The levels of TC, TG, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) in mouse serum and the levels of MDA, GSH, SOD, TNF-α, and IL-6 in liver tissues were measured. Pathological changes in liver tissues were evaluated using hematoxylin-eosin (HE) and Oil Red O staining. Protein expression of Nrf2, Keap1, HO-1, GPX4, and NF-κB p65 in liver tissues was detected by Western blotting, and the expression level of GPX4 in the liver was examined by immunohistochemistry. Results: Sericin and Zhibitai Capsules improved hepatic steatosis and lipid accumulation in NAFLD model mice. TC, TG, LDL-C, MDA, and TNF-α, IL-6 levels were down-regulated, and HDL-C and SOD levels were up-regulated. There was no significant difference in the expression of AST and ALT in all the groups. In addition, Sericin and Zhibitai Capsules upregulated the expression levels of Nrf2, keap1, HO-1, and GPX4 proteins and inhibited the expression of NF-κB p65 in the liver of NAFLD model mice. There was no significant difference in serum lipids and liver indices between the 1000 mg/kg sericin + ML385 group and the sericin dose groups. Conclusion: Sericin has an ameliorative effect on liver injury in NAFLD model mice by alleviating oxidative stress and inflammatory responses in liver injury. It remains to be explored whether this effect is regulated through the Nrf2- GPX4/ NF-κB p65 signaling pathway.

TM6SF2 E167K variant decreases PNPLA3-mediated PUFA transfer to promote hepatic steatosis and injury in MASLD.

Transmembrane 6 superfamily member 2 (TM6SF2) E167K variant is closely associated with the occurrence and development of metabolic dysfunction-associated steatotic liver disease (MASLD). However, the role and mechanism of TM6SF2 E167K variant during MASLD progression are not yet fully understood. The Tm6sf2167K knock-in (KI) mice were subjected to high-fat diet (HFD). Hepatic lipid levels of Tm6sf2167K KI mice were detected by lipidomics analysis. Thin-layer chromatography (TLC) was used to measure the newly synthesized triglyceride (TG) and phosphatidylcholine (PC). The TM6SF2 E167K variant significantly aggravated hepatic steatosis and injury of HFD-induced mice. Decreased polyunsaturated PC level and increased polyunsaturated TG level were found in liver tissue of HFD-induced Tm6sf2167K KI mice. Mechanistic studies demonstrated that the TM6SF2 E167K variant increased the interaction between TM6SF2 and PNPLA3, and impaired PNPLA3-mediated transfer of polyunsaturated fatty acids (PUFAs) from TG to PC. The TM6SF2 E167K variant increased the level of fatty acid-induced malondialdehyde and reactive oxygen species, and decreased fatty acid-downregulated cell-membrane fluidity. Additionally, the TM6SF2 E167K variant decreased the level of hepatic PC containing C18:3, and dietary supplementation of PC containing C18:3 significantly attenuated the TM6SF2 E167K-induced hepatic steatosis and injury in HFD-fed mice. The TM6SF2 E167K variant could promote its interaction with PNPLA3 and inhibit PNPLA3-mediated transfer of PUFAs from TG to PC, resulting in the hepatic steatosis and injury during MASLD progression. PC containing C18:3 could act as a potential therapeutic supplement for MASLD patients carrying the TM6SF2 E167K variant.

Hepatocyte activation and liver injury following cerebral ischemia promote HMGB1-mediated hepcidin upregulation in hepatocytes and regulation of systemic iron levels.

We previously reported that high mobility group box 1 (HMGB1), a danger-associated molecular pattern (DAMP), increases intracellular iron levels in the postischemic brain by upregulating hepcidin, a key regulator of iron homeostasis, triggering ferroptosis. Since hepatocytes are the primary cells that produce hepcidin and control systemic iron levels, we investigated whether cerebral ischemia induces hepcidin upregulation in hepatocytes. Following middle cerebral artery occlusion (MCAO) in a rodent model, significant liver injury was observed. This injury was evidenced by significantly elevated Eckhoff's scores and increased serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Additionally, total iron levels were significantly elevated in the liver, with intracellular iron accumulation detected in hepatocytes. Hepcidin expression in the liver, which is primarily localized in hepatocytes, increased significantly starting at 3 h after MCAO and continued to increase rapidly, reaching a peak at 24 h. Interestingly, HMGB1 levels in the liver were also significantly elevated after MCAO, with the disulfide form of HMGB1 being the major subtype. In vitro experiments using AML12 hepatocytes showed that recombinant disulfide HMGB1 significantly upregulated hepcidin expression in a Toll-like receptor 4 (TLR4)- and RAGE-dependent manner. Furthermore, treatment with a ROS scavenger and a peptide HMGB1 antagonist revealed that both ROS generation and HMGB1 induction contributed to hepatocyte activation and liver damage following MCAO-reperfusion. In conclusion, this study revealed that cerebral ischemia triggers hepatocyte activation and liver injury. HMGB1 potently induces hepcidin not only in the brain but also in the liver, thereby influencing systemic iron homeostasis following ischemic stroke.

Swertia cincta and its main active ingredients regulate the PPAR-α pathway in anti-cholestatic liver injury

Ethnopharmacological relevanceSwertia cincta is a traditional remedy for cholestasis commonly utilised in Yunnan, China. Despite its widespread use, the specific active components and underlying mechanisms of action remain poorly understood. Aim of this studyThis study aimed to investigate the therapeutic properties, mechanisms, and active compounds of Swertia cincta in an animal model of cholestasis induced by alpha-naphthylisothiocyanate (ANIT). Materials and methodsUHPLC/Q-TOF-MS and high-performance liquid chromatography (HPLC) were utilised to analyse the blood components of Swertia cincta. An ANIT-induced cholestatic liver injury animal model was established, and metabolomics was employed to explore the potential mechanisms of Swertia cincta in treating cholestatic liver injury. Hepatocellular injury induced by taurochenodeoxycholic acid was evaluated in vitro, and key bioactive components of Swertia cincta for cholestatic liver injury treatment were identified and confirmed using the ANIT-induced mouse model. ResultsThe established HPLC method demonstrates good specificity and reproducibility, enabling the simultaneous determination of six components in Swertia cincta. Results from serum biochemical indicators and liver pathology analysis indicated that Swertia cincta exhibits promising anti-cholestasis liver injury effects. Specifically, gentiopicroside, loganic acid, and isoorientin were identified as key active ingredients in treating cholestatic liver injury. Their mechanism of action primarily involves regulating PPAR-α, FXR, CYP3A4, NTCP, CAR, and CPT2. By modulating PPAR-α and bile acid metabolism-related proteins, reducing pro-inflammatory factors, enhancing bile acid transport, and promoting fatty acid oxidation to reduce lipid accumulation, Swertia cincta exerts protective and therapeutic effects against cholestatic liver injury. Notably, gentian bitter glycosides appear to be the most critical components for this effect. ConclusionSwertia cincta may improve cholestatic liver injury by activating the peroxisome proliferator-activated receptor alpha pathway, and the key active compounds were gentiopicroside, loganic acid, and isoorientin.

Insufficient S-sulfhydration of Serum and Glucocorticoid-regulated Kinase 1 Participates in Hyperhomocysteinemia-induced Liver Injury.

Previous studies have established that hyperhomocysteinemia (HHcy) significantly contributes to the development of non-alcoholic steatohepatitis (NASH). Conversely, hydrogen sulfide (H2S) has shown potential in mitigating NASH. Despite these findings, it remains uncertain whether H2S can serve as a therapeutic agent against HHcy-induced liver damage. Mice were fed a high-methionine diet to induce HHcy and HepG2 cells were exposed to homocysteine (Hcy). In both models, we assessed liver injury, H2S concentration, and autophagy levels. For rescue, sodium hydrosulfide (NaHS), an H2S donor, was used to test its potential in reversing hepatic pathological features induced by HHcy. 1) Hcy accumulation led to liver damage and increased autophagy. This was linked to insufficient S-sulfhydration of serum and glucocorticoid-regulated kinase 1 (SGK1) at Cys244 and Cys282, a crucial autophagy regulator. The deficiency in S-sulfhydration was resulted from downregulation of cystathionine-γ-lyase (CSE) and subsequent H2S decrease, leading to SGK1 inactivation. 2) Administration of NaHS reduced the liver damage caused by high Hcy levels and restored H2S levels, promoting the S-sulfhydration and activation of SGK1. 3) Pharmacological inhibition of SGK1 induced autosis, a specific type of cell death caused by overactivation of autophagy. Conversely, a constitutively active mutant of SGK1 (SGK1S422D) significantly decreased autophagy and improved cell viability. NaHS supplementation mitigates HHcy-induced liver injury by downregulating hepatic autophagy through the S-sulfhydration and activation of SGK1. This post-translational modification by H2S holds promise as a therapeutic approach for HHcy-induced liver injury.

The chemokine receptor type 5 inhibitor maraviroc alleviates sepsis-associated liver injury by regulating MAPK/NF-κB signaling.

Sepsis-related organ damage, as the most intractable problem in intensive care units (ICUs), receives a great deal of attention from healthcare professionals. Sepsis-associated liver injury (SALI) often leads to poor clinical outcomes due to its complex physiological mechanism. In previous studies, chemokine receptor 5 (CCR5) inhibitors were shown to exert unique anti-inflammatory effects. As the therapeutic effect of maraviroc (MVC) on SALI is still unclear, we aimed to explore whether MVC is effective in treating SALI. We established a model of SALI by cecal ligation and puncture (CLP) and intraperitoneally injected 20mg/kg MVC 2h after CLP. The results showed that MVC could significantly ameliorate liver injury after CLP. Furthermore, we demonstrated that MVC reduced inflammatory infiltration and apoptosis after SALI. In addition, we found that the function of MVC in reducing inflammation was obtained through the inhibition of the two inflammatory signaling pathways mentioned above. Finally, the JNK agonist AN was chosen for reverse research. As shown by the results, the therapeutic effects of MVC disappeared after AN treatment, indicating that MVC exerted anti-inflammatory and antiapoptotic effects through JNK. Our study revealed that MVC could reduce liver injury after SALI by inhibiting liver inflammation and hepatocyte apoptosis induced by CLP and that MVC exerted diminish inflammatory effects by inhibiting the NF-κB and MAPK signaling pathways.

Severe acute liver disease in adults: Contemporary role of histopathology.

Liver biopsies have consistently contributed to our understanding of the pathogenesis and aetiologies of acute liver disease. As other diagnostic modalities have been developed and refined, the role of biopsy in the management of patients with acute liver failure (ALF), acute-on-chronic liver failure (ACLF) and acute hepatitis, including acute liver injury (ALI), has changed. Liver biopsy remains particularly valuable when first-line diagnostic algorithms fail to determine aetiology. Despite not being identified as a mandatory diagnostic tool in recent clinical guidelines for the management of ALF or ACLF, many centres continue to undertake biopsies given the relative safety of transjugular biopsy in this setting. Several studies have demonstrated that liver biopsy can provide prognostic information, particularly in the context of so-called indeterminate hepatitis, and is extremely useful in excluding conditions such as metastatic tumours that would preclude transplantation. In addition, its widespread use of percutaneous biopsies in cases of less severe acute liver injury, for example in the establishment of a diagnosis of acute presentation of autoimmune hepatitis or confirmation of a probable or definite drug-induced liver injury (DILI), has meant that many centres have seen a shift in the ratio of specimens they are receiving from patients with chronic to acute liver disease. Histopathologists therefore need to be equipped to deal with these challenging specimens. This overview provides an insight into the contemporary role of biopsies (as well as explant and autopsy material) in diagnosing acute liver disease. It outlines up-to-date clinical definitions of liver injury and considers recent recommendations for the diagnosis of AIH and drug-induced, autoimmune-like hepatitis (DI-AIH).

Aqueous Extract of Rhubarb Promotes Hepatotoxicity via Facilitating PKM2-Mediated Aerobic Glycolysis in a Rat Model of Diethylnitrosamine-Induced Liver Cancer.

To identify the polar parts in Rhubarb that cause hepatotoxicity and explore the underlying mechanisms. The rat model of liver cancer was established by gavage of diethylnitrosamine (DEN; 0.002 g/rat) for 14weeks. Starting from the 11th week, Rhubarb granule (4 g/kg), aqueous, ethyl acetate and n-butanol extract of Rhubarb or Rhein equivalent to a dose of 4 g/kg Rhubarb granule were administered intragastrically for 4 consecutive weeks. Liver tissues from rats treated with DEN and Rhubarb granules were used for non-targeted metabolomics analysis. The correlation between pyruvate kinase isozyme type M2 (PKM2) expression level and the progress and prognosis of hepatocellular carcinoma (HCC) was evaluated through bioinformatics analysis based on TCGA database. Liver tissues and blood samples from rats treated with DEN and aqueous, ethyl acetate and n-butanol extract of Rhubarb were used for the screening of hepatotoxic polar parts of Rhubarb. The liver injuries were evaluated by the changes in pathology, liver function, and the expression levels of proliferating cell nuclear antigen (PCNA) and transforming growth factor beta1 (TGF-β1). The mechanism studies focus on PKM2 expression, and the metabolic reprogramming via detecting the activities of lactate dehydrogenase A (LDHA) and isocitrate dehydrogenase (ICDH). Furthermore, molecular docking analysis was performed to validate the target interaction between Rhein and PKM2, and the hepatotoxicity of Rhein was evaluated by testing liver function in the DEN-induced liver cancer model. The non-targeted metabolomics analysis revealed that Rhubarb promoted aerobic glycolysis in the rat model of DEN-induced liver cancer. And bioinformatics analysis revealed that high PKM2 expression was closely related to the progression and poor prognosis of HCC. In vivo studies indicated that the aqueous extract of Rhubarb, but not ethyl acetate and n-butanol extract, promoted the liver injuries induced by DEN. The mechanism study showed that the aqueous extract of Rhubarb increased the expression of PKM2 and promoted aerobic glycolysis. Moreover, Rhein had a strong binding affinity for PKM2 and aggravated liver injury in the DEN-induced liver cancer model. Aqueous extract of Rhubarb promoted hepatotoxicity via facilitating PKM2-mediated aerobic glycolysis in the rat model of DEN-induced liver cancer.

Neoastilbin ameliorates sepsis-induced liver and kidney injury by blocking the TLR4/NF-κB pathway.

Sepsis frequently causes systemic inflammatory response syndrome and multiple organ failure in patients. Neoastilbin (NAS) is a flavonoid that plays vital functions in inflammation. This work aims to investigate the protective effects of NAS against sepsis-induced liver and kidney injury and elucidate its underlying mechanisms. The mouse model was established using cecal ligation puncture (CLP) induction. NAS was given to mice by gavage for 7 consecutive days before surgery. Liver and kidney function, oxidative stress, and inflammatory factors in serum or tissues were examined by ELISA or related kits. The expression of relevant proteins was assessed by Western blot. Hematoxylin and eosin and/or periodic acid-Schiff staining revealed that NAS ameliorated the pathological damage in liver and kidney tissues of CLP-induced mice. NAS improved liver and kidney functions, as evidenced by elevated levels of blood urea nitrogen, Creatinine, ALT, and AST in the serum of septic mice. TUNEL assay and the expression of Bcl-2 and Bax showed that NAS dramatically reduced apoptosis in liver and renal tissues. NAS treatment lowered the levels of myeloperoxidase and malondialdehyde, while elevated the superoxide dismutase content in liver and kidney tissues of CLP-induced mice. The levels of inflammatory cytokines (IL-6, TNF-α, and IL-1β) in the serum and both tissues of CLP-injured mice were markedly decreased by NAS. Mechanically, NAS downregulated TLR4 expression and inhibited NF-κB activation, and overexpression of TLR4 reversed the protective effects of NAS against liver and kidney injury. Collectively, NAS attenuated CLP-induced apoptosis, oxidative stress, inflammation, and dysfunction in the liver and kidney by restraining the TLR4/NF-κB pathway.

Identifying specific functional roles for senescence across cell types.

Cellular senescence plays critical roles in aging, regeneration, and disease; yet, the ability to discern its contributions across various cell types to these biological processes remains limited. In this study, we generated an invivo genetic toolbox consisting of three p16Ink4a-related intersectional genetic systems, enabling pulse-chase tracing (Sn-pTracer), Cre-based tracing and ablation (Sn-cTracer), and gene manipulation combined with tracing (Sn-gTracer) of defined p16Ink4a+ cell types. Using liver injury and repair as an example, we found that macrophages and endothelial cells (ECs) represent distinct senescent cell populations with different fates and functions during liver fibrosis and repair. Notably, clearance of p16Ink4a+ macrophages significantly mitigates hepatocellular damage, whereas eliminating p16Ink4a+ ECs aggravates liver injury. Additionally, targeted reprogramming of p16Ink4a+ ECs through Kdr overexpression markedly reduces liver fibrosis. This study illuminates the functional diversity of p16Ink4a+ cells and offers insights for developing cell-type-specific senolytic therapies in the future.

Loss of Cdkn1a protects against MASLD alone or with alcohol intake by preserving lipid homeostasis

Background & AimExpression of P21, encoded by the CDKN1A gene, has been associated with fibrosis progression in steatotic liver disease (SLD); however, the underlying mechanisms remain unknown. In the present study, we investigated the function of CDKN1A in SLD. MethodsCDKN1A expression levels were evaluated in different patients‘ cohorts with SLD, fibrosis, and advanced chronic liver disease (ACLD). Cdkn1a-/- and Cdkn1a+/+ mice were fed with either a Western diet (WD), a Lieber-DeCarli (LdC) diet plus multiple EtOH binges, or a DuAL diet. Primary hepatocytes were isolated and functional assays performed. ResultsA significant increase in CDKN1A expression was observed in patients with steatohepatitis and fibrosis (with a positive correlation with both NAS and fibrosis staging scores), cirrhosis and ACLD. Cdkn1a+/+ mice, fed a DuAL diet exhibited liver injury and cell death increased reactive oxygen species (ROS), and markers of senescence (γH2AX, β-GAL, Cdkn1a/p53) contributing to steatosis and inflammation. In contrast, Cdkn1a-/- mutant mice showed a significant decrease in senescence-associated markers as well as in markers of liver injury, hepatic steatosis and an increase in – fatty acid oxidation (FAO) and reduction in free fatty acid (FFA) uptake as well as de novo lipogenesis. Mechanistically, activation of the AMPK-SIRT3 was observed in Cdkn1a-deleted animals. ConclusionsCdkn1a deletion protected against preclinical SLD by promoting FAO and preventing FFA uptake and de novo lipogenesis via the AMPK-SIRT3 axis. CDKN1A expression was found to be directly correlated with increased severity of NAS and fibrosis in SLD patients. CDKN1A could be a potential theragnostic target for the treatment of metabolic dysregulation in SLD patients, with and without alcohol consumption.

S4661 A Case of Herbs and Dietary Supplements-Drug-Induced Liver Injury From Unripe Ackee Fruit!

S4661 A Case of Herbs and Dietary Supplements-Drug-Induced Liver Injury From Unripe Ackee Fruit!

Investigation of the Role of Chemical Analysis in Causality Assessment of Herbal and Dietary Supplement-Induced Liver Injury.

The attribution of drug-induced liver injury (DILI) to specific herbal and dietary supplements (HDS) is confounded by inaccurate labels and undisclosed ingredients. The US Drug-Induced Liver Injury Network (DILIN) determines the attribution of injury to an agent through its structured expert opinion causality assessment process, but without the use of chemical analysis data of HDS. We aimed to determine the impact of chemical analysis of HDS products on prior causality assessment scores. Obtained samples of HDS consumed by DILIN-enrolled patients were analyzed by high-performance liquid chromatography-mass spectrometry (HPLC-MS). Chemical analysis data were compared to label accuracy and detect whether the product contained botanical and non-botanical compounds. A comparison of the causality scores reassessed with chemical analysis was compared with the original scores. A total of 54 previously adjudicated cases with chemical analysis available were reassessed for causality with chemical analysis data; reviewers were blinded to original causality scores. Using the chemical analysis data, 37% (n = 20) of the 54 cases were scored with a higher likelihood of DILI compared with the original causality scores; 14 of the 20 (70%) moved from probable to highly likely; 52% had no change in causality score; and 11% of cases were scored as a lower likelihood of DILI. Our study demonstrates that there is value in using HDS chemical analysis data in the causality assessment process for DILI. In more than a third of cases, chemical analysis of products led to an increased confidence in DILI attribution to HDS. These findings suggest that chemical analysis is an important tool in causality assessment for HDS agents, specifically in challenging situations, and further studies are needed to confirm its applicability in clinical practice.

Caveolin-1 ameliorates hepatic injury in non-alcoholic fatty liver disease by inhibiting ferroptosis via the NOX4/ROS/GPX4 pathway

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease globally, with a complex and contentious pathogenesis. Caveolin-1 (CAV1) is an important regulator of liver function and can mitigate liver injury by scavenging reactive oxygen species (ROS). Evidence suggests that NOX4 is a source of ROS production, that oxidative stress and ferroptosis are closely related, and that both are involved in the onset and progression of NAFLD. However, whether CAV1 attenuates liver injury in NAFLD caused by high-fat diet via the NOX4/ROS/GPX4 pathway remains unclear. An in vivo fatty liver model was established by feeding mice with a high-fat diet for 16 weeks. In addition, an in vitro fatty liver model was established by incubating AML-12 cells with free fatty acids for 24 h using an in vitro culture method. In our study, it was observed that a high-fat diet induces mitochondrial damage and worsens oxidative stress in NAFLD. This diet also hinders GPX4 expression, leading to an escalation of ferroptosis and lipid accumulation. To counteract these effects, intraperitoneal administration of CSD peptide in mice attenuated the high-fat diet-induced liver mitochondrial damage and ferroptosis. Likewise, overexpression of CAV1 resulted in an increase in GPX4 expression and a reduction in levels of ROS-mediated iron metamorphosis, thus mitigating the progression of the disease. However, the effects of CAV1 on GPX4-mediated ferroptosis and lipid deposition could be reversed by CAV1 small interfering RNA (SiRNA). Finally, NOX4 inhibitor (GLX351322) treatment increased CAV1 siRNA-mediated GPX4 expression and decreased the level of ROS-mediated ferroptosis. These findings suggest a potential mechanism underlying the protective role of CAV1 against high-fat diet-induced hepatotoxicity in NAFLD, shedding new light on the interplay between CAV1, GPX4, and ferroptosis in liver pathology