Hepatocyte Damage Research Articles

Hepatic neddylation deficiency triggers fatal liver injury via inducing NF-κB-inducing kinase in mice

The conjugation of neural precursor cell expressed, developmentally downregulated 8 (NEDD8) to target proteins, termed neddylation, participates in many cellular processes and is aberrant in various pathological diseases. Its relevance to liver function and failure remains poorly understood. Herein, we show dysregulated expression of NAE1, a regulatory subunit of the only NEDD8 E1 enzyme, in human acute liver failure. Embryonic- and adult-onset deletion of NAE1 in hepatocytes causes hepatocyte death, inflammation, and fibrosis, culminating in fatal liver injury in mice. Hepatic neddylation deficiency triggers oxidative stress, mitochondrial dysfunction, and hepatocyte reprogramming, potentiating liver injury. Importantly, NF-κB-inducing kinase (NIK), a serine/Thr kinase, is a neddylation substrate. Neddylation of NIK promotes its ubiquitination and degradation. Inhibition of neddylation conversely causes aberrant NIK activation, accentuating hepatocyte damage and inflammation. Administration of N-acetylcysteine, a glutathione surrogate and antioxidant, mitigates liver failure caused by hepatic NAE1 deletion in adult male mice. Therefore, hepatic neddylation is important in maintaining postnatal and adult liver homeostasis, and the identified neddylation targets/pathways provide insights into therapeutically intervening acute liver failure.

Natural Product 2-Oxokolavenol Is a Novel FXR Agonist.

Acetaminophen (APAP) toxicity is a common cause of hepatic failure, and the development of effective therapy is still urgently needed. Farnesoid X receptor (FXR), a member of the nuclear receptor superfamily, has been identified as a master gene for regulating enterohepatic metabolic homeostasis and has proven to be a promising drug target for various liver diseases. Through high-throughput chemical screening, the natural product 2-oxokolavenol was identified as a novel and selective FXR agonist. Further investigations revealed that 2-oxokolavenol exerts therapeutic efficacy against APAP-induced hepatocyte damage in an FXR-dependent manner. Mechanistically, 2-oxokolavenol forms two hydrogen bonds with M265 and Y369 of human FXR to compatibly fit into the ligand binding pocket of FXR, which potently leads to the recruitment of multiple co-regulators and selectively induces the transcriptional activity of FXR. Our findings thus not only reveal the direct target of natural product 2-oxokolavenol, but also provide a promising hit compound for the design of new FXR modulators with potential clinical value.

Polygonatum sibiricum saponin Exerts Beneficial Hypoglycemic Effects in Type 2 Diabetes Mice by Improving Hepatic Insulin Resistance and Glycogen Synthesis-Related Proteins.

Type 2 diabetes mellitus (T2DM) is a systemic metabolic disorder characterized by insulin deficiency and insulin resistance. Recently, it has become a significant threat to public health. Polygonatum sibiricum saponin (PSS) has potential hypoglycemic effects, but its specific mechanism needs further study. In this study, PSS significantly decreased the level of blood glucose, water intake, and the organ index in diabetic mice. Meanwhile, PSS effectively reduced the content of total triglyceride (TG), total cholesterol (TCHO), low-density lipoprotein cholesterol (LDL-C), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) in the blood, and increased the content of high-density lipoprotein cholesterol (HDL-C). This suggests that PSS could reduce the content of blood lipids and initially improve the damage of hepatocytes. We found that PSS alleviated hepatic insulin resistance, repaired islet beta cells, and enabled insulin to play its biological role normally. It also improved oral glucose tolerance and abated serum lipopolysaccharide (LPS) and glycosylated hemoglobin (HbA1c) levels in T2DM mice. Furthermore, studies have found that PSS increased the content of phosphorylated protein kinase B (AKT), thereby promoting the effect of glucose transporter 4 (GLUT-4), and activating glycogen synthase kinase 3beta (GSK-3β) and glycogen synthase (GS) proteins to promote hepatic glycogen synthesis. Finally, we found that PSS could promote the growth of beneficial bacteria such as Bifidobacterium and Lactobacillus, reduce the growth of harmful bacteria such as Enterococcus and Enterobacter, and preliminarily improve the composition of important bacteria in the intestine. These studies indicate that PSS has an excellent hypoglycemic effect, which provides a potential new treatment for T2DM and guidance for more in-depth research.

CCN2/CTGF promotes liver fibrosis through crosstalk with the Slit2/Robo signaling

Liver fibrosis is the common outcome of many chronic liver diseases, resulting from altered cell-cell and cell-matrix interactions that promote hepatic stellate cell (HSC) activation and excessive matrix production. This study aimed to investigate functions of cellular communication network factor 2 (CCN2)/Connective tissue growth factor (CTGF), an extracellular signaling modulator of the CYR61/CTGF/Nov (CCN) family, in liver fibrosis. Tamoxifen-inducible conditional knockouts in mice and hepatocyte-specific deletion of this gene in rats were generated using the Cre-lox system. These animals were subjected to peri-central hepatocyte damage caused by carbon tetrachloride. Potential crosstalk of this molecule with a new profibrotic pathway mediated by the Slit2 ligand and Roundabout (Robo) receptors was also examined. We found that Ccn2/Ctgf was highly upregulated in periportal hepatocytes during carbon tetrachloride-induced hepatocyte damage, liver fibrosis and cirrhosis in mice and rats. Overexpression of this molecule was observed in human hepatocellular carcinoma (HCC) that were surrounded with fibrotic cords. Deletion of the Ccn2/Ctgf gene significantly reduced expression of fibrosis-related genes including Slit2, a smooth muscle actin (SMA) and Collagen type I during carbon tetrachloride-induced liver fibrosis in mice and rats. In addition, Ccn2/Ctgf and its truncated mutant carrying the first three domains were able to interact with the 7th -9th epidermal growth factor (EGF) repeats and the C-terminal cysteine knot (CT) motif of Slit2 protein in cultured HSC and fibrotic murine livers. Ectopic expression of Ccn2/Ctgf protein upregulated Slit2, promoted HSC activation, and potentiated fibrotic responses following chronic intoxication by carbon tetrachloride. Moreover, Ccn2/Ctgf and Slit2 synergistically enhanced activation of phosphatidylinositol 3-kinase (PI3K) and AKT in primary HSC, whereas soluble Robo1-Fc chimera protein could inhibit these activities. These observations demonstrate conserved cross-species functions of Ccn2/Ctgf protein in rodent livers. This protein can be induced in hepatocytes and contribute to liver fibrosis. Its novel connection with the Slit2/Robo signaling may have therapeutic implications against fibrosis in chronic liver disease.

Toosendanin Induces Hepatocyte Damage by Inhibiting Autophagic Flux via TFEB-Mediated Lysosomal Dysfunction.

Toosendanin (TSN) is a triterpenoid from the fruit or bark of Melia toosendan Sieb et Zucc, which has clear antitumor and insecticidal activities, but it possesses limiting hepatotoxicity in clinical application. Autophagy is a degradation and recycling mechanism to maintain cellular homeostasis, and it also plays an essential role in TSN-induced hepatotoxicity. Nevertheless, the specific mechanism of TSN on autophagy-related hepatotoxicity is still unknown. The hepatotoxicity of TSN in vivo and in vitro was explored in this study. It was found that TSN induced the upregulation of the autophagy-marker microtubule-associated proteins 1A/1B light chain 3B (LC3B) and P62, the accumulation of autolysosomes, and the inhibition of autophagic flux. The middle and late stages of autophagy were mainly studied. The data showed that TSN did not affect the fusion of autophagosomes and lysosomes but significantly inhibited the acidity, the degradation capacity of lysosomes, and the expression of hydrolase cathepsin B (CTSB). The activation of autophagy could alleviate TSN-induced hepatocyte damage. TSN inhibited the expression of transcription factor EB (TFEB), which is a key transcription factor for many genes of autophagy and lysosomes, such as CTSB, and overexpression of TFEB alleviated the autophagic flux blockade caused by TSN. In summary, TSN caused hepatotoxicity by inhibiting TFEB-lysosome-mediated autophagic flux and activating autophagy by rapamycin (Rapa), which could effectively alleviate TSN-induced hepatotoxicity, indicating that targeting autophagy is a new strategy to intervene in the hepatotoxicity of TSN.

The Berberis vulgaris L. extract berberine exerts its anti-oxidant effects to ameliorate cholesterol overloading-induced cell apoptosis in the primary mice hepatocytes: an in vitro study.

Cholesterol overloading stress damages normal cellular functions in hepatocytes and induces metabolic disorders to facilitate the development of multiple diseases, including cardiovascular diseases, which seriously degrades the life quality of human beings. Recent data suggest that the Berberis vulgaris L. extract berberine is capable of regulating cholesterol homeostasis, which is deemed as potential therapeutic drug for the treatment of cholesterol overloading-associated diseases, but its detailed functions and molecular mechanisms are still largely unknown. In the present study, we evidenced that berberine suppressed cell apoptosis in high-cholesterol-diet mice liver and cholesterol-overloaded mice hepatocytes. Also, cholesterol overloading promoted reactive oxygen species (ROS) generation to trigger oxidative damages in hepatocytes, which were reversed by co-treating cells with both berberine and the ROS scavenger N-acetylcysteine (NAC). Moreover, the underlying mechanisms were uncovered, and we validated that berberine downregulated Keap1, and upregulated Nrf2 to activate the anti-oxidant Nrf2/HO-1 signaling pathway in cholesterol overloading-treated hepatocytes, and both Keap1 upregulation and Nrf2 downregulation abrogated the suppressing effects of berberine on cell apoptosis in the hepatocytes with cholesterol exposure. Taken together, we concluded that berberine activated the anti-oxidant Keap1/Nrf2/HO-1 pathway to eliminate cholesterol overloading-induced oxidative stress and apoptotic cell death in mice hepatocytes, and those evidences hinted that berberine might be used as putative therapeutic drug for the treatment of cholesterol overloading-associated cardiovascular diseases.

Water extract of lotus leaves has hepatoprotective activity by enhancing Nrf2- and epigenetics-mediated cellular antioxidant capacity in mouse hepatocytes

• The main phenolics in LL-WE were EGCG, rutin, gallic acid, myricetin, quercetin, ellagic acid, etc. • LL-WE reduced the damage of mouse AML-12 hepatocytes caused by APAP-induced oxidative stress. • LL-WE promoted glutathione synthesis and activated the Nrf2 pathway. • LL-WE upregulated Nrf2-mediated antioxidant enzymes and downregulated HDACs and DNMTs. • LL-WE inhibited the in vitro activity of CpG methyltransferase (M.SssI). The liver is an important organ in the human body; however, studies have shown that the excessive intake of acetaminophen (APAP), the primary ingredient in marketing pain relievers, may cause oxidative damage to liver cells. Here we found that lotus leaf water extract (LL-WE) enriched with various phenolic compounds can prevent mice AML-12 hepatocytes from APAP-induced injury, and trigger the Nrf2 pathway in HepG2-C8 cells with ARE-luciferase plasmid. LL-WE effectively induced Nrf2 nuclear translocation and glutathione synthesis, increased gene expression of antioxidant enzymes (HO-1, NQO1, and UGT1A), and reduced protein levels of epigenetic modification enzymes (HDACs and DNMTs) in AML-12 cells. LL-WE also inhibited the activity of M.SssI CpG methyltransferase in vitro . These results suggest that LL-WE can be a potential hepatoprotective agent to reduce oxidative stress-induced liver damage by activating the Nrf2 pathway and downregulating epigenetic modification enzymes.

Amelioration effects of leaf extract of Centella asiatica on sodium arsenate induced hepatotoxicity in zebra fish

• The inorganic arsenite and arsenate found in water as the most prevalent forms. • Excessive exposure to inorganic arsenate in drinking water causes a slew of health issues in human. • Hepatocytes are exposed to xenobiotics; they undergo morphological and structural damage. • Centella asiatica has the potential to reduce the cytotoxicity triggered by sodium arsenate in zebrafish. Arsenic contamination in drinking water is a major public health concern. It is classified as an environmental pollutant that necessitates immediate corrective action. Long-term arsenic exposure may cause hepatotoxicity. The current research focuses on the effectiveness of a methanolic extract of Centella asiatica against sodium arsenate-induced hepatotoxicity in Danio rerio (Zebrafish). Phytochemicals and bioactive compounds in C.asiatica extract were studied using standard procedure and GC-MS analysis. The extract was also assessed for antioxidant and antibacterial properties. The significant scavenging activity of oxygen-free radicals as well as the IC50 values was observed. Furthermore, the ability of C.asiatica (500 mg/g) leaf extract to alleviate hepatotoxicity in Zebrafish pretreated and post-treated with sodium arsenate (100g/l) was observed. In this work, phytochemical examination of C.asiatica leaf extract revealed the presence of bioactive substances such as alkaloids, flavonoids, terpenoids, glycosides, phenolics, proteins, and carbohydrates, which was validated by GC MS analysis of different percentage areas. Importantly, the methanolic extract of C.asiatica demonstrated strong antimicrobial and antioxidant activities. The plant extract, in particular, demonstrated its efficiency by alleviating the effects of arsenate in the liver of zebrafish (both pre-and post-treatment), as demonstrated by histological analysis. The results of histopathological research revealed that methanolic extract of C.asiatica had a considerable lowering effect on sodium arsenate-induced hepatocyte damage in zebrafish. As a result, the inhibitory action of Centella asiatica methanolic extract may be investigated to create effective candidates to fight arsenate toxicity.

Hepatopathology of flaviviruses.

Acute hepatitis can be caused by a variety of viruses, many of which are uncommon in the United States. Diagnosis requires virus-specific molecular and/or antigen-based tests, but disease severity can be assessed using a set of classical liver function tests. An increase in alanine aminotransferase (ALT) levels in serum is an early and specific indicator of hepatocyte damage. ALT concentrations are proportional to the degree of hepatocyte injury but can be elevated even in subclinical cases. Derangements in hepatic excretory function (as measured by blood concentrations of bilirubin), synthetic function (prolongation of the prothrombin time), and metabolic function (hyperammonemia) indicate progressively more serious liver dysfunction.

Mitochondria stimulate liver regeneration in rats

Abstract Regenerative medicine is a vital area that advances methods addressing the process of liver regeneration. The liver has the unique ability to return to standard size within a short period of time after its injury or partial hepatectomy. Hepatocytes are highly active metabolic cells, which have a large number of mitochondria, suggesting a biologically significant role for the mitochondrial dynamics in hepatocyte damage and repair. The aim hereof is to develop a method for accelerating the process of liver regeneration in rats based on the transplantation of mitochondria isolated from the liver of intact rats. Materials and methods. Experimental animals (n = 30) used by us were white outbred rats divided into groups as follows: 1) a comparison group to include intact animals (n = 10); 2) a reference group with liver resection + use of saline solution (n = 10); 3) the main group with liver resection + mitochondrial therapy (MCT) (n = 10). In the reference and the main groups, under xylazoletil anesthesia, median laparotomy was performed and the maximum allowable resection of the left lobe of the liver was executed. Mitochondria of the intact liver were diluted with a 0.9% NaCl solution to a protein concentration of 11.6 g/l and injected into the post-surgery rats of the main group (group No. 3). The above procedure was carried out for 14 days. Animals of the reference group were intraperitoneally injected with 0.5 ml of saline solution according to a similar scheme. Statistical analysis was performed with the Statistica 10.0 Software. Results. According to the weight indices of the liver after MCT, the mass of the organ increased by a factor of 1.7 р˂0.05) relative to the reference group without MCT. At the same time, compared with the indicators in animals of the comparison group (intact animals), the mass of the organ exceeded 1.6 times (p˂0.05), and the liver stump itself during MCT in its mass exceeded by 3.2 times the weight indicators of the liver stump in rats without the MCT. Conclusion. As a result of the experiment on the use of MCT of the liver, it can be concluded that the resection of the liver lobe and subsequent processes in the liver tissue against the background of MCT acquire pronounced features of accelerating the physiological regeneration, addressing the restoration of stromal and parenchymal components.

Staphylococcal enterotoxin A induces DNA damage in hepatocytes and liver tissues

Staphylococcal enterotoxin A (SEA) is a foodborne bacterial toxin that can cause food poisoning, but little research has been done on the DNA damage caused by SEA. The aim of this research was to investigate the action of SEA in inducing DNA damage and oxidative stress response in hepatocytes and liver tissues. After treating HL-7702 and BRL-3A cells with different concentrations of SEA (0, 300, 600 ng/mL and 0, 400, 800 ng/mL), the production of phosphorylated H2AX (γH2AX) and p53 binding protein 1 (53BP1) aggregates was detected by confocal fluorescence microscopy, and the increases in ataxia telangiectasia mutated (ATM), checkpoint kinase 2 (Chk2), p53 protein expression were assessed by Western blot analysis, while increased reactive oxygen species (ROS) content was confirmed by flow cytometry and fluorescence probe. The genotoxicity of SEA to cells was attenuated after the addition of an oxidative inhibitor, demonstrating that SEA induced intracellular DNA damage through the oxidative pathway and a dose-dependent relationship was observed between the oxidation index and SEA. These experimental results deepen our understanding of SEA damage to cells at the genetic level, and provide a new orientation for the prevention and cure of food borne diseases caused by Staphylococcal enterotoxins (SEs).

The glucotoxicity protecting effect of honokiol in human hepatocytes via directly activating AMPK.

Sustained hyperglycemia causes glucotoxicity, which has been regarded as a contributor to hepatocyte damage in type 2 diabetes (T2D) and its metabolic comorbidities. Honokiol is a natural biphenolic component derived from the dietary supplement Magnolia officinalis extract. This study aimed to investigate the effects of honokiol on glucose metabolism disorders and oxidative stress in hepatocytes and the underlying mechanisms. HepG2 cells were treated with glucosamines (18 mM) to induce glucotoxicity as a diabetic complication model in vitro. Honokiol significantly increased glucose consumption, elevated 2-NBDG uptake, and promoted GLUT2 translocation to the plasma membrane in glucosamine-treated HepG2 cells, indicating that honokiol ameliorates glucose metabolism disorders. Furthermore, glucosamine-induced ROS accumulation and loss of mitochondrial membrane potential were markedly reduced by honokiol, suggesting that honokiol alleviated glucotoxicity-induced oxidative stress. These effects were largely abolished by compound C, an AMPK inhibitor, suggesting an AMPK activation-dependent manner of honokiol function in promoting glucose metabolism and mitigating oxidative stress. Molecular docking results revealed that honokiol could interact with the amino acid residues (His151, Arg152, Lys243, Arg70, Lys170, and His298) in the active site of AMPK. These findings provide new insights into the antidiabetic effect of honokiol, which may be a promising agent for the prevention and treatment of T2D and associated metabolic comorbidities.

Serum Fibroblast Growth Factor 19 as a Biomarker in Hepatitis B Virus-Related Liver Disease

Background: Past research has found that fibroblast growth factor 19 (FGF19) is associated with several hepatic disorders, such as alcoholic liver disease and primary biliary cirrhosis. However, there is currently a lack of relevant studies on the relationship between FGF19 and hepatitis B virus (HBV)-related liver disease. Objectives: This study aimed to assess the role of serum FGF19 as a new biomarker for HBV-related liver disease and provide scientific data to show the clinical value of this biomarker. Methods: A retrospective study included 37 patients with chronic hepatitis B (CHB), 33 patients with HBV-related cirrhosis (HBV-cirrhosis), and 32 patients with HBV-related hepatocellular carcinoma (HBV-HCC). Furthermore, 33 normal people were randomly selected as healthy controls. The serum levels of FGF19 were measured by ELISA. Results: Serum FGF19 levels were increased sequentially in the CHB group, HBV-cirrhosis group, and HBV-HCC group. Furthermore, serum FGF19 levels positively correlated with alpha-fetoprotein, prothrombin time, international normalized ratio, total bilirubin, direct bilirubin, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl-transferase, alkaline phosphatase, total bile acid, serum markers for liver fibrosis, ascites, cirrhosis, Child-Pugh classification and model for end-stage liver disease sodium (MELD-Na) score, while negatively correlated with platelet count, prothrombin activity, and albumin. The diagnostic threshold of serum FGF19 for HBV-related HCC was 165.32 pg/mL, with a sensitivity of 81.25% and specificity of 58.57%. Conclusions: Serum FGF19 levels are positively associated with cholestasis, hepatocyte damage, and liver fibrosis but negatively correlated with liver synthetic function and liver functional reserve in HBV-related liver disease. Diverse changes in serum FGF19 may be used as a predictive marker for the progression of HBV-related liver disease. In addition, serum FGF19 has a potential role in monitoring carcinogenesis in patients with HBV-related liver disease.

Metabolic reprogramming of hepatocytes by Schistosoma mansoni eggs

Schistosomiasis is a parasitic infection which affects more than 200 million people globally. Schistosome eggs, but not the adult worms, are mainly responsible for schistosomiasis-specific morbidity in the liver. It is unclear if S.mansoni eggs consume host metabolites, and how this compromises the host parenchyma. Metabolic reprogramming was analyzed by matrix-assisted laser desorption/ionization mass spectrometry imaging, liquid chromatography with high-resolution mass spectrometry, metabolite quantification, confocal laser scanning microscopy, live cell imaging, quantitative real-time PCR, western blotting, assessment of DNA damage, and immunohistology in hamster models and functional experiments in human cell lines. Major results were validated in human biopsies. The infection with S. mansoni provokes hepatic exhaustion of neutral lipids and glycogen. Furthermore, the distribution of distinct lipid species and the regulation of rate-limiting metabolic enzymes is disrupted in the liver of S. mansoni infected animals. Notably, eggs mobilize, incorporate, and store host lipids, while the associated metabolic reprogramming causes oxidative stress-induced DNA damage in hepatocytes. Administration of reactive oxygen species scavengers ameliorates these deleterious effects. Our findings indicate that S.mansoni eggs completely reprogram lipid and carbohydrate metabolism via soluble factors, which results in oxidative stress-induced cell damage in the host parenchyma. The authors demonstrate that soluble egg products of the parasite S.mansoni induce hepatocellular reprogramming, causing metabolic exhaustion and a strong redox imbalance. Notably, eggs mobilize, incorporate, and store host lipids, while the metabolic reprogramming causes oxidative stress-induced DNA damage in hepatocytes, independent of the host's immune response. S. mansoni eggs take advantage of the host environment through metabolic reprogramming of hepatocytes and enterocytes. By inducing DNA damage, this neglected tropical disease might promote hepatocellular damage and thus influence international health efforts.

Effect of Myricetin on Lipid Metabolism in Primary Calf Hepatocytes Challenged with Long-Chain Fatty Acids.

Triacylglycerol (TAG) accumulation and oxidative damage in hepatocytes induced by high circulating concentrations of fatty acids (FA) are common after calving. In order to clarify the role of myricetin on lipid metabolism in hepatocytes when FA metabolism increases markedly, we performed in vitro analyses using isolated primary calf hepatocytes from three healthy female calves (1 d old, 42 to 48 kg). Two hours prior to an FA challenge (1.2 mM mix), the hepatocytes were treated with 100 μM (M1), 50 μM (M2), or 25 μM (M3) of myricetin. Subsequently, hepatocytes from each donor were challenged with or without FA for 12 h in an attempt to induce metabolic stress. Data from calf hepatocyte treatment comparisons were assessed using two-way repeated-measures (RM) ANOVA with subsequent Bonferroni correction. The data revealed that hepatocytes challenged with FA had greater concentrations of TAG and nonesterified fatty acids (NEFA), oxidative stress-related MDA and H2O2, and mRNA and protein abundance of lipid synthesis-related SREBF1 and inflammatory-related NF-κB. In addition, the mRNA abundance of the lipid synthesis-related genes FASN, DGAT1, DGAT2, and ACC1; endoplasmic reticulum stress-related GRP79 and PERK; and inflammatory-related TNF-α also were upregulated. In contrast, the activity of antioxidant SOD (p < 0.01) and concentrations of GSH (p < 0.05), and the protein abundance of mitochondrial FA oxidation-related CPT1A, were markedly lower. Compared with FA challenge, 50 and 100 μM myricetin led to lower concentrations of TAG, NEFA, MDA, and H2O2, as well as mRNA and protein abundance of SREBF1, DGAT1, GRP78, and NF-κB. In contrast, the activity of SOD (p < 0.01) and mRNA and protein abundance of CPT1A were markedly greater. Overall, the results suggest that myricetin could enhance the antioxidant capacity and reduce lipotoxicity, endoplasmic reticulum stress, and inflammation. All of these effects can help reduce TAG accumulation in hepatocytes.

Biomarkers of growth and carbohydrate metabolism in neonatal rats supplemented with fish oil and/or antioxidants during intermittent hypoxia

ObjectiveExtremely low gestational age neonates (ELGANs) experience frequent intermittent hypoxia (IH) episodes during therapeutic oxygen. ELGANs exhibit poor postnatal growth requiring lipid supplementation. Lipids are targets of reactive oxygen species resulting in lipid peroxidation and cell death, particularly in preterm infants with compromised antioxidant systems. We tested the hypothesis that early supplementation with lipids and/or antioxidants promotes growth and influences biomarkers of carbohydrate metabolism in neonatal rats exposed to IH. DesignNewborn rats (n = 18/group) were exposed to brief hypoxia (12% O2) during hyperoxia (50% O2), or room air (RA), from birth (P0) to P14 during which they received daily oral supplementation with: 1) fish oil; 2) Coenzyme Q10 (CoQ10) in olive oil; 3) glutathione nanoparticles (nGSH); 4) fish oil+CoQ10; or 5) olive oil. At P21, plasma samples were assessed for glucose, insulin, glucokinase (GCK), glucagon, glucagon-like peptide (GLP)-1, growth hormone (GH), corticosterone, and ghrelin. Liver was assessed for histopathology, apoptosis (terminal deoxynucleotidyl transferase dUTP nick end labeling, TUNEL stain), and GH, insulin-like growth factor (IGF)-I, GH binding protein (GHBP), and IGF binding protein (IGFBP)-3. ResultsNeonatal IH resulted in decreased liver weight and liver/body weight ratios, as well as hepatocyte swelling, steatosis, and apoptosis, which were attenuated with fish oil, nGSH, and combined fish oil+CoQ10. IH also decreased plasma glucose, insulin, GCK, and ghrelin, but increased GLP-1. All treatments improved plasma glucose in IH, but insulin was higher with CoQ10 and nGSH only. Glucagon was increased with CoQ10, fish oil, and CoQ10 + fish oil, while corticosterone was higher with nGSH and CoQ10 + fish oil. IGF-I and IGFBP-3 were significantly higher in the liver with CoQ10 in IH, while deficits in GH were noted with CoQ10 and fish oil in RA and IH. Treatment with nGSH and combined CoQ10 + fish oil reduced IGF-I in RA and IH but increased IGFBP-3. ConclusionsNeonatal IH impairs liver growth with significant hepatocyte damage. Of all supplements in IH, nGSH and combined fish oil+CoQ10 were most effective for preserving liver growth and carbohydrate metabolism. Data suggest that these supplements may improve poor postnatal organ and body growth; and metabolic dysfunction associated with neonatal IH.

Etiopathogenesis and pathophysiology of cholestasis

Normal hepatobiliary function depends on an adequate bile flow from the liver through the biliary tree to the gallbladder, where bile is stored and concentrated, and from the gallbladder to the duodenum when it is required for the digestive process. Interruption of this secretory function results in partial or complete cholestasis, which is accompanied by important repercussions due to the lack of bile acids in the intestine and their regurgitation from hepatocytes to blood together with potentially toxic compounds that are normally eliminated in bile. The presence of active and selective transporter proteins located at both poles of the plasma membrane of hepatocytes, cholangiocytes, and epithelial cells of the ileal mucosa, together with the ability of hepatocytes to synthesize bile acids from cholesterol, enables the so-called bile acid enterohepatic circulation, which is essential in liver and gastrointestinal tract physiology. The presence in the ducts of the biliary tree of agents reducing their luminal diameter by external compression or space-occupying obstacles, either in the duct wall or its lumen, can result in total or partial obstructive cholestasis. The clinical impact and management of cholestasis are different depending on the intrahepatic or extrahepatic location of the obstacle. Thus, surgical interventions can often be helpful in removing extrahepatic obstructions and restoring normal bile flow to the duodenum. In contrast, hepatocyte or cholangiocyte damage, either global, restricted to subcellular compartments, or more specifically affecting the elements of the canalicular secretory machinery, may result in hepatocellular cholestasis or cholangiopathies. In these cases, bile flow interruption is usually partial and, except for extremely severe cases when liver transplantation is required, these patients often treated with pharmacological agents, such as ursodeoxycholic acid (UDCA) and rifampicin. The present review gathers updated information on the etiopathogenesis and pathophysiological aspects of different types of cholestasis.

Liposome cocktail activator modulates hepatocytes and remodels the microenvironment to mitigate acute liver failure

Acute liver failure (ALF) is a mortal and critical hepatic disease, in which oxidative stress, inflammation storm and hepatocyte death are crucial in the pathogenesis. Hence, in contrast to the control of a single link, a combination therapy targeting multiple pathogenic links of the disease will be a favorable means to control the progression of the disease. In this study, we constructed dimethyl itaconate-loaded liposomes modified with dodecyl gallate as a cocktail activator to investigate its functional role in acetaminophen (APAP)-induced ALF. Our results demonstrated that the cocktail activator acted on hepatocytes and triggered cocktail efficacy, thereby simultaneously attenuating APAP-induced hepatocyte damage and remodeling the damage microenvironment. The cocktail activator could effectively scavenge reactive oxygen species, inhibit excessive inflammatory responses and reduce cell death in impaired hepatocytes for detoxification. More importantly, the cocktail activator could remodel the damage microenvironment, thus further promoting hepatocyte expansion and specifically switching macrophages from the M1 to M2 phenotype for a favorable liver regeneration of ALF. Furthermore, in APAP-induced ALF mouse model, the cocktail activator improved liver function, alleviated histopathological damage and increased survival rate. In summary, these findings indicate that the cocktail activator may provide a promising therapeutic approach for ALF treatment as a nanomedicine.

Inhibition of HSPA8 by rifampicin contributes to ferroptosis via enhancing autophagy.

Rifampicin is the most common pathogenic factor in anti-tuberculosis drug-induced liver injury (AT-DILI), the mechanisms that it promotes hepatocyte damage in AT-DILI are not yet to be thoroughly elucidated. In this study, we investigated the potential molecular mechanisms for ferroptosis involving rifampicin hepatotoxicity. Animal and cell injury models of rifampicin were constructed, and the toxicity of rifampicin was assessed by physicochemical staining and cell viability assay. Next, flow cytometry was employed to detect changes in ferroptosis-related markers, and Western blotting was used to detect protein expression. Then, the important role of autophagy and ferroptosis was verified with small molecule compound intervention. We found that ferritinophagy-induced ferroptosis participates in the toxicity of rifampicin, and the mechanism is that rifampicin precisely activates high-throughput autophagy, which leads to the massive degradation of ferritin and the increase of free iron. Moreover, rifampicin exhibited conspicuous inhibition of Human 71 kDa heat shock cognate protein (HSPA8) that is intimately associated with Microtubule-associated protein light chain 3 isoform B (LC3B) expression, in turn, HSPA8 inducer attenuated intracellular autophagy flux. Of note, inducing HSPA8 or inhibition of autophagy and ferroptosis considerably relieved the hepatotoxicity of rifampicin in mouse model. The present study highlights the crucial roles of the HSPA8 and autophagy in ferroptotic cell death driving by rifampicin, particularly illumines multiple promising regulatory nodes for therapeutic interventions in diseases involving AT-DILI.

Isolation and Identification of Antioxidative Peptide from Goose Liver Hydrolysate to Ameliorate Alcohol-Mediated Oxidative Stress Damage in HHL-5 Hepatocytes.

The aim of this study was to isolate and identify antioxidative peptide from goose liver hydrolysate (GLHP) for ameliorating oxidative stress damage by alcohol in HHL-5 hepatocytes. In this research, the target antioxidative peptides in GLHP were separated, purified, and identified via a tangential flow ultrafiltration system combined with size exclusion chromatography (SEC), ion exchange chromatography (IEC), reversed-phase liquid chromatography (RP-LC), and LC-MS/MS. The results suggested that the amino acid sequence of the target antioxidative peptide for ameliorating alcohol-mediated oxidative stress damage in HHL-5 hepatocytes was Leu-Pro-Leu-Pro-Phe-Pro (LPLPFP), which had a molecular weight of 683.41 Da, and was derived from NADH-ubiquinone oxidoreductase chain 1 in goose liver. In addition, LPLPFP was confirmed to have a satisfactory stability and maintained high hepatic protective activity in a simulated gastrointestinal digestion. Moreover, the mechanism of LPLPFP prevented against oxidative stress damage in HHL-5 hepatocytes was attributed to inhibiting the production of reactive oxide species (ROS) by upregulating genes expression in the Ahr-NQO1 signal pathway. In conclusion, these results indicated that dietary GLHP supplementation could ameliorate alcohol-mediated oxidative stress damage and provide an affordable dietary intervention strategy to prevent alcohol-mediated hepatocyte damage.