Apoptotic Hepatocytes Research Articles

Fatal Yellow Fever in a Kidney Transplant Patient.

A kidney-transplanted patient, unvaccinated against yellow fever (YF), developed high fever, progressed rapidly to hepatic insufficiency and coma, and died 8 days later. Real-time polymarase chain reaction for YF virus collected on the seventh day of symptoms was positive. Autopsy showed disseminated infection and midzonal hepatitis with apoptotic hepatocytes and minimal inflammatory reaction.

Up-regulation of miR-155 contributes to TNF-mediated hepatocyte apoptosis in acute liver failure.

Acute liver failure (ALF) is due to severe immune response, resulting in massive apoptosis/necrosis of hepatocytes. The precise mechanism has not been explored yet. The mouse with ALF model was induced by D-GalN/LPS; the hepatic miRNAs expression profile was evaluated by miRNA microarray and verified by RT-PCR. During the ALF in mice, the miR-155 expression was detected in the liver as well as in spleen. Then the correlation between miR-155 and inflammatory cytokines was evaluated. Furthermore, the miR-155 expression in activated Raw264.7 cells and apoptotic hepatocytes was also studied. Finally, the regulatory roles of miR-155 in TNF expression of apoptotic hepatocytes were shown. It was shown that miRNAs changed in the mice with ALF relating to hepatocytes apoptosis/necrosis; the selected miRNAs were confirmed with RT-PCR. miR-155 was up-regulated, but miR-698, -720, and -329 were down-regulated. Moreover, hepatic miR-155 was up-regulated at all-time points in the liver, but only at 7 h in spleen of mice with ALF. A significant correlation was observed between hepatic miR-155 and TNF/IL-6 in mice with ALF, which was supported by the findings in vitro showing up-regulated miR-155 in Raw264.7 cells and Hepa1-6 cells under LPS or D-GalN+TNF induction, respectively. Moreover, a correlation was observed between miR155 and TNF levels in vivo and in vitro. These data demonstrate that miR-155 regulates TNF-mediated hepatocyte apoptosis in ALF, which provides some useful information in both basic and clinical researches.

Bone marrow mesenchymal stem cells could reduce the toxic effects of hexavalent chromium on the liver by decreasing endoplasmic reticulum stress-mediated apoptosis via SIRT1/HIF-1α signaling pathway in rats

This study focused on the effect of bone marrow mesenchymal stem cells (BMSCs) on the repair of rat liver injury induced by Cr (VI). Twenty-four Wistar rats were randomly divided into the control, model and cell therapy group, with 8 rats in each group. Potassium dichromate solution containing 0, 0.4 and 0.4 mg/kg·bw Cr (VI) was administered 5 times a week for 30 days. At the end of treatment, rats in the cell therapy group were administered 1 × 107 BMSCs. Two weeks later, serum alanine and aspartate aminotransferase levels in the cell therapy group were significantly improved compared with those in the model group, CM-Dil-labeled BMSCs were localized in rat livers. Compared with the model group, in the cell therapy group the number of apoptotic hepatocytes by TUNEL assay, MDA content, the expression of HIF-1α, endoplasmic reticulum (ER) stress-mediated apoptosis-related proteins including Grp78, CHOP, Cleaved-Caspase-12, ATF6, and Bax was significantly lower, and SOD activity, the expression of SIRT1 and Bcl-2 was significantly higher. It is suggested that BMSCs are localized in livers and reduce the toxic effects of Cr (VI) on the liver, and the possible mechanism may be related to the mechanisms of BMSCs decreasing ER stress-mediated hepatocyte apoptosis via the SIRT1/HIF-1α signaling pathway.

Influence of the long-term exposure to tartrazine and chlorophyll on the fibrogenic signalling pathway in liver and kidney of rats: the expression patterns of collagen 1-α, TGFβ-1, fibronectin, and caspase-3 genes.

Colouring agents are highly present in diverse products in the human environment. We aimed to elucidate the fibrogenic cascade triggered by the food dyes tartrazine and chlorophyll. Rats were orally given distilled water, tenfold of the acceptable daily intake of tartrazine, or chlorophyll for 90 consecutive days. Tartrazine-treated rats displayed a significant rise (p< 0.05) in the mRNA levels and immunohistochemical localization of the renal and hepatic fibrotic markers collagen 1-α, TGFβ-1, and fibronectin and the apoptotic marker caspase-3. Moreover, a significant increment (p< 0.05) in the levels of AST, ALP, creatinine, and urea was evident in both experimental groups but more significant differences were noticed in the tartrazine group. Furthermore, we found a marked increment in the MDA level and significant declines (p< 0.05) in the levels of the SOD, CAT, and GSH enzymes in the kidney and liver from tartrazine-treated rats. The histological investigation reinforced the aforementioned data, revealing hepatocytes with fibrous connective tissue proliferation, apoptotic hepatocytes and periportal fibrosis with tubular necrosis, and shrunken glomeruli and interstitial fibrous tissue proliferation. We concluded that, even at the exposure to high concentrations for long durations, chlorophyll exhibited a lower propensity to induce fibrosis, apoptosis, and histopathological perturbations than tartrazine.

Novel Interplay Between Sonic Hedgehog and Transforming Growth Factor-β1 in Human Nonalcoholic Steatohepatitis.

Nonalcoholic steatohepatitis (NASH) has the potential to progress to fibrosis, cirrhosis, and hepatocellular carcinoma. Upregulation of sonic hedgehog (Shh) has been documented in development of NASH through sustained cell stress. At the same time, transforming growth factor-β1 (TGF-β1), which is a central element in fibrogenic reactions in various diseases and sites, has been reported to be associated with hepatic inflammation and fibrotic reaction. To explore crosstalk between Shh and TGF-β1 in the development and progression of NASH, we investigated the expression of both these proteins in 135 human specimens of NASH, 35 fatty liver specimens, 35 specimens of alcoholic steatohepatitis with immunohistochemistry. Shh protein was expressed in the cytoplasm of ballooned hepatocytes with an ubiquitin-like pattern. In addition, a few scattered apoptotic hepatocytes in the inflammatory foci showed homogeneous cytoplasmic Shh expression. TGF-β1 protein was observed mainly in the activated hepatic stellate cells (HSCs) which were located in the inflammatory foci surrounding ballooned hepatocytes. Moreover, the mRNA levels of both Shh and TGF-β1 in the liver biopsy specimens from NASH patients was significantly increased compared with those in fatty liver patients. Statistically, there was a significant association of the expressions of Shh and TGF-β1 proteins in NASH (r=0.6, P<0.05). In addition, increased expression of Shh protein significantly parallels the severity of hepatocellular ballooning, lobular, and portal inflammatory responses and progression of fibrosis in NASH patients. Moreover, we found that much HSCs transformed into myofibroblast-like phenotype and migrated downward to HepG2 hepatocellular carcinoma cells with overexpression of Shh by transwell assay. We also observed overexpression of proteins of Shh and TGF-β1 in cultured activated HSCs with confocal microscopy. These findings strongly suggest there is interplay between Shh and TGF-β1 in hepatic inflammatory reactions. Shh secreted through damaged hepatocytes may result in activation of TGF-β1 and subsequent transformation of HSCs, which together modulate the progression of human NASH.

Citicoline Protects against Tramadol-Induced Oxidative Stress and Organ Damage

Tramadol is a common drug of abuse which has been shown to cause neurodegeneration in the rat brain. Cytidine-5'-diphosphocholine or citicoline is an intermediate in the synthesis of phosphatidylcholine and is in use in humans for the treatment of several brain pathologies. In this study, we aimed to investigate the effect of citicoline on oxidative stress and tissue injury caused by tramadol, an opioid drug. Rats were treated with tramadol at 30 mg/kg alone or in combination with citicoline at 50, 100, or 200 mg/kg orally, once a day, for 10 days. Other groups were treated with only 0.9% saline or only citicoline at 200 mg/kg. Lipid peroxidation (malondialdehyde), nitric oxide, reduced glutathione (GSH), and paraoxonase-1 (PON-1) activity were measured in the serum. Bone marrow DNA fragmentation assay and micronucleus test were also done. In addition, histopathological examination of the brain, liver, and kidney, and immunohistochemical staining for glial cell acidic fibrillary protein (GFAP) in the cerebral cortex were performed. Results indicated that compared to the saline-treated group, repeated tramadol administration led to significant increases in serum malondialdehyde and nitric oxide concentrations by 50.0% and 70.0%, respectively. There was also a decline in GSH content and PON-1 activity in the serum by 26.3% and 51.4%, respectively. Tramadol caused marked DNA fragmentation and increased the number of micronucleated polychromatic erythrocytes (MnPCE) in bone marrow by 192.8% and 876.3%, respectively, compared with the corresponding saline control values. Histopathological studies revealed neuronal degeneration (acidophilic cytoplasm and dark nuclei) and decreased GFAP immunostaining in the cerebral cortex of tramadol-treated rats. The liver exhibited fibrosis, apoptotic hepatocytes, and inflammatory cell infiltration. Vacuolar degeneration of the tubular lining epithelium and edema of glomeruli were observed in the kidney. Citicoline administered to saline-treated rats at a dose of 200 mg/kg showed no significant effect on serum malondialdehyde, nitric oxide, GSH concentrations, or PON-1 activity compared with the saline control group. Citicoline by itself had no effect on DNA fragmentation or the number of MnPCE in the bone marrow. In tramadol-treated rats, however, citicoline (50–200 mg/kg) resulted in a significantly decreased malondialdehyde by 23.8%–31.6%. Nitric oxide decreased by 29.2%–36.2% after citicoline at 50–200 mg/kg. There was also a significant increase in both GSH by 19.6%–33.6% and in PON-1 activity by 54.8%–125.7%. In addition, citicoline caused a significant decrease in DNA fragmentation (by 29.2%–52.4%) and the number of MnPCE in the bone marrow (by 20.5%–59.5%) in tramadol-treated rats. Histopathological changes caused by tramadol in the brain, liver, and kidney were ameliorated by treatment with citicoline. We conclude that citicoline treatment results in decreased lipid peroxidation and nitric oxide along with increased GSH content and PON-1 activity in the serum of rats treated with tramadol. These changes might account for the beneficial effect of citicoline in decreasing DNA fragmentation and tissue injury caused by tramadol.

Mito-tempo protects against acute liver injury but induces limited secondary apoptosis during the late phase of acetaminophen hepatotoxicity.

We previously reported that delayed treatment with Mito-tempo (MT), a mitochondria-targeted superoxide dismutase mimetic, protects against the early phase of acetaminophen (APAP) hepatotoxicity by inhibiting peroxynitrite formation. However, whether this protection is sustained to the late phase of toxicity is unknown. To investigate the late protection, C57Bl/6J mice were treated with 300mg/kg APAP followed by 20mg/kg MT 1.5h or 3h later. We found that both MT treatments protected against the late phase of APAP hepatotoxicity at 12 and 24h. Surprisingly, MT-treated mice demonstrated a significant increase in apoptotic hepatocytes, while the necrotic phenotype was observed almost exclusively in mice treated with APAP alone. In addition, there was a significant increase in caspase-3 activity and cleavage in the livers of MT-treated mice. Immunostaining for active caspase-3 revealed that the positively stained hepatocytes were exclusively in centrilobular areas. Treatment with the pan-caspase inhibitor ZVD-fmk (10mg/kg) 2h post-APAP neutralized this caspase activation and provided additional protection against APAP hepatotoxicity. Treatment with N-acetylcysteine, the current standard of care for APAP poisoning, protected but did not induce this apoptotic phenotype. Mechanistically, MT treatment inhibited APAP-induced RIP3 kinase expression, and RIP3-deficient mice showed caspase activation and apoptotic morphology in hepatocytes analogous to MT treatment. These data suggest that while necrosis is the primary cause of cell death after APAP hepatotoxicity, treatment with the antioxidant MT may switch the mode of cell death to secondary apoptosis in some cells. Modulation of mitochondrial oxidative stress and RIP3 kinase expression play critical roles in this switch.

Hepatitis C Virus-Infected Apoptotic Hepatocytes Program Macrophages and Hepatic Stellate Cells for Liver Inflammation and Fibrosis Development: Role of Ethanol as a Second Hit.

Hepatocyte apoptosis is a crucially important mechanism for liver disease pathogenesis, and the engulfment of apoptotic bodies (AB) by non-parenchymal cells serves as a leading mechanism of inflammation and fibrosis progression. Previously, we have shown that hepatitis C virus (HCV) and alcohol metabolites induce massive apoptosis in hepatocytes and the spread of HCV-infection to the neighboring uninfected cells. Here, we hypothesize that the capturing of AB by non-parenchymal cells, macrophages and hepatic stellate cells (HSC) changes their phenotype to promote inflammation and fibrosis. In this regard, we generated AB from Huh7.5CYP2E1 (RLW) cells also treated with an acetaldehyde-generating system (AGS) and incubated them with human monocyte-derived macrophages (MDMs) and HSC (LX2 cells). Activation of inflammasomes and pro-fibrotic markers has been tested by RT-PCR and linked to HCV expression and AGS-induced lipid peroxidation in RLW cells. After exposure to AB we observed activation of inflammasomes in MDMs, with a higher effect of AB HCV+, further enhanced by incubation of MDMs with ethanol. In HSC, activation of inflammasomes was modest; however, HCV and AGS exposure induced pro-fibrotic changes. We conclude that HCV as well as lipid peroxidation-adducted proteins packaged in AB may serve as a vehicle for delivery of parenchymal cell cargo to non-parenchymal cells to activate inflammasomes and pro-fibrotic genes and promote liver inflammation and fibrosis.

Dietary Iron Overload Abrogates Chemically-Induced Liver Cirrhosis in Rats.

Chronic liver disease is an intractable disease, which can progress to cirrhosis and hepatocellular carcinoma. Hepatic iron overload is considered to be involved in the progression of chronic liver diseases; however, the mechanism remains to be elucidated. Here we investigate the role of dietary iron overload using chemically-induced liver cirrhosis model. Rats were fed a high-iron or standard diet and were injected intraperitoneally with thioacetamide (TAA) or saline twice a week for 20 weeks. Rats with TAA treatment (TAA group) had progressive liver cirrhosis characterized by persistent hepatocellular injury, mononuclear cell inflammation and bridging fibrosis; these lesions were markedly reduced in rats with iron feeding and TAA treatment (Fe-TAA group). Rats with iron feeding alone (Fe group) had no evidence of liver injury. Hepatic expression of cleaved caspase-3, but not phospho-RIP3, was decreased in Fe-TAA group compared with that in TAA group. The number of TUNEL-positive (terminal deoxynucleotidyl transferase dUTP nick end labeling) apoptotic hepatocytes was lower in the Fe-TAA group than in the TAA group. Hepatic xenobiotic metabolism and lipid peroxidation were shown to be less related to the abrogation of liver cirrhosis. Our results suggested that dietary hepatic iron overload abrogates chemically-induced liver cirrhosis in rats, which could partly involve decreased hepatocellular apoptosis.

Danshensu Rescues Ischemia/Reperfusion Caused Human Hepatocyte Death

Apoptosis of hepatocyte, under ischemia/reperfusion (IR) conditions, has been identified as an essential process in the progression of liver transplantation. Under these conditions, mitochondria can become a threat to the cell because of their capacity to generate reactive oxygen species (ROS). Additionally, ROS overproduction may induce inflammation. As ROS accumulation appears to cause hepatocyte damage or death, there has been considerable interest in identifying the candidate natural products involved and in developing strategies to reduce oxidative stress. In this study, we use Danshensu as a candidate product to speculate whether has the protective effect on apoptotic hepatocyte upon IR. To speculate the apoptotic phenomena was reversed by Danshensu, we detected the p53, cleaved-caspase 3 expression by western blotting, as well as caspase-3 activity. Additionally, we analyzed the ROS levels by 2′,7′-dichlorofluorescin diacetate (DCF-DA) staining. We also detected the cell viability by WST-1. Results showed that Danshensu alleviated hypoxia-caused cell apoptosis via ROS overproduction. We suggested that Danshensu is a good strategy for treating hepatocyte damage upon IR.

Hydrogen sulfide protects against acetaminophen-induced acute liver injury by inhibiting apoptosis via the JNK/MAPK signaling pathway.

Acetaminophen (APAP) is a widely used over-the-counter analgesic and antipyretic. It can cause hepatotoxicity. Recent studies demonstrated that hydrogen sulfide (H2 S) exhibits cell protection in several cell types. This study was designed to investigate whether H 2 S ameliorated APAP-induced acute liver injury and to elucidate its mechanisms. In this study, we analyzed the detailed biological and molecular processes of APAP-induced hepatotoxicity using a bioinformatics analysis, which showed that apoptosis and the c-Jun N-terminal kinase (JNK)/mitogen-activated protein kinase pathway were confirmed to play critical roles in these processes. We further investigated the protective effects of H 2 S on APAP-induced hepatotoxicity. In vivo, we observed that the exogenous supplement of H 2 S ameliorated APAP-induced liver injury. Cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE) systems were the endogenous pathway of H 2 S. The expression of CBS/CSE was decreased in APAP-treated mice, while H 2 S could significantly restore it. In addition, APAP-induced JNK activation was inhibited by H 2 S in vivo. In vitro, H 2 S abolished the active effects of APAP on caspase3, Bax, and Bcl-2 expressions as well as JNK phosphorylation in hepatocytes. It was found through flow cytometry that the amount of APAP-induced apoptotic hepatocytes was decreased in the presence of H 2 S. In conclusion, our results suggested that H 2 S attenuated APAP-induced apoptosis in hepatocytes through JNK/MAPK siganaling pathway.

Trovafloxacin-Induced Liver Injury: Lack in Regulation of Inflammation by Inhibition of Nucleotide Release and Neutrophil Movement.

The fluoroquinolone trovafloxacin (TVX) is associated with a high risk of drug-induced liver injury (DILI). Although part of the liver damage by TVX+TNF relies on neutrophils, we have recently demonstrated that liver recruitment of monocytes and neutrophils is delayed by TVX. Here we show that the delayed leukocyte recruitment is caused by a combination of effects which are linked to the capacity of TVX to block the hemichannel pannexin 1. TVX inhibited find-me signal release in apoptotic HepG2 hepatocytes, decelerated freshly isolated human neutrophils toward IL-8 and f-MLF, and decreased the liver expression of ICAM-1. In blood of TVX+TNF-treated mice, we observed an accumulation of activated neutrophils despite an increased MIP-2 release by the liver. Depletion of monocytes and neutrophils caused increased serum concentrations of TNF, IL-6, and MIP-2 in TVX-treated mice as well as in mice treated with the fluoroquinolone levofloxacin, known to have a lower DILI-inducing profile. This supports the idea that early leukocyte recruitment regulates inflammation. In conclusion, disrupted regulation by leukocytes appears to constitute a fundamental step in the onset of TVX-induced liver injury, acting in concert with the capability of TVX to induce hepatocyte cell death. Interference of leukocyte-mediated regulation of inflammation represents a novel mechanism to explain the onset of DILI.

Macrophage Raptor Deficiency-Induced Lysosome Dysfunction Exacerbates Nonalcoholic Steatohepatitis.

Background & AimsNonalcoholic steatohepatitis (NASH) is an increasingly prevalent nonalcoholic fatty liver disease, characterized by inflammatory cell infiltration and hepatocellular damage. Mammalian target of rapamycin complex 1 (mTORC1) has been investigated extensively in the context of cancer, including hepatocellular carcinoma. However, the role of mTORC1 in NASH remains largely unknown.MethodsmTORC1 activity in macrophages in human mild and severe NASH liver was compared. Mice with macrophage-specific deletion of the regulatory-associated protein of mTOR (Raptor) subunit and littermate controls were fed a high-fructose, palmitate, and cholesterol diet for 24 weeks or a methionine- and choline-deficient diet for 4 weeks to develop NASH.ResultsWe report that in human beings bearing NASH, macrophage mTORC1 activity was lower in livers experiencing severe vs mild NASH liver. Moreover, macrophage mTORC1 disruption exacerbated the inflammatory response in 2 diet-induced NASH mouse models. Mechanistically, in response to apoptotic hepatocytes (AHs), macrophage polarization toward a M2 anti-inflammatory phenotype was inhibited in Raptor-deficient macrophages. During the digestion of AHs, macrophage mTORC1 was activated and coupled with dynamin-related protein 1 to facilitate the latter’s phosphorylation, leading to mitochondrial fission-mediated calcium release. Ionomycin or A23187, calcium ionophores, prevented Raptor deficiency–mediated failure of lysosome acidification and subsequent lipolysis. Blocking dynamin-related protein 1–dependent mitochondria fission impaired lysosome function, resulting in reduced production of anti-inflammatory factors such as interleukins 10 and 13.ConclusionsPersistent mTORC1 deficiency in macrophages contributes to the progression of NASH by causing lysosome dysfunction and subsequently attenuating anti-inflammatory M2-like response in macrophages during clearance of AHs.

Necroptosis microenvironment directs lineage commitment in liver cancer.

Primary liver cancer represents a major health problem. It comprises hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC), which differ markedly with regards to their morphology, metastatic potential and responses to therapy. However, the regulatory molecules and tissue context that commit transformed hepatic cells towards HCC or ICC are largely unknown. Here we show that the hepatic microenvironment epigenetically shapes lineage commitment in mosaic mouse models of liver tumorigenesis. Whereas a necroptosis-associated hepatic cytokine microenvironment determines ICC outgrowth from oncogenically transformed hepatocytes, hepatocytes containing identical oncogenic drivers give rise to HCC if they are surrounded by apoptotic hepatocytes. Epigenome and transcriptome profiling of mouse HCC and ICC singled out Tbx3 and Prdm5 as major microenvironment-dependent and epigenetically regulated lineage-commitment factors, a function that is conserved in humans. Together, our results provide insight into lineage commitment in liver tumorigenesis, and explain molecularly why common liver-damaging risk factors can lead to either HCC or ICC.

Prevention of acute liver injury by suppressing plasma kallikrein-dependent activation of latent TGF-β

Acute liver injury (ALI) is highly lethal acute liver failure caused by different etiologies. Transforming growth factor β (TGF-β) is a multifunctional cytokine and a well-recognized inducer of apoptotic and necrotic cell death in hepatocytes. Latent TGF-β is activated partly through proteolytic cleavage by a serine protease plasma kallikrein (PLK) between the R58 and L59 residues of its propeptide region. Recently, we developed a specific monoclonal antibody to detect the N-terminal side LAP degradation products ending at residue R58 (R58 LAP-DPs) that reflect PLK-dependent TGF-β activation. This study aimed to explore the potential roles of PLK-dependent TGF-β activation in the pathogenesis of ALI. We established a mouse ALI model via the injection of anti-Fas antibodies (Jo2) and observed increases in the TGF-β1 mRNA level, Smad3 phosphorylation, TUNEL-positive apoptotic hepatocytes and R58-positive cells in the liver tissues of Jo2-treated mice. The R58 LAP-DPs were observed in/around F4/80-positive macrophages, while macrophage depletion with clodronate liposomes partly alleviated the Jo2-induced liver injury. Blocking PLK-dependent TGF-β activation using either the serine proteinase inhibitor FOY305 or the selective PLK inhibitor PKSI-527 or blocking the TGF-β receptor-mediated signaling pathway using SB431542 significantly prevented Jo2-induced hepatic apoptosis and mortality. Furthermore, similar phenomena were observed in the mouse model of ALI with the administration of acetaminophen (APAP). In summary, R58 LAP-DPs reflecting PLK-dependent TGF-β activation may serve as a biomarker for ALI, and targeting PLK-dependent TGF-β activation has potential as a therapeutic strategy for ALI.

Protective Effect of Eckol against Acute Hepatic Injury Induced by Carbon Tetrachloride in Mice.

Several in vitro studies have shown the potential hepatoprotective properties of eckol, a natural phlorotannin derived from the brown alga. However, the in vivo hepatoprotective potential of eckol has not been determined. In this study, we performed an in vivo study to investigate the protective effect of eckol and its possible mechanisms on the carbon tetrachloride (CCl4)-induced acute liver injury model in mice. Results revealed that eckol pre-treatment at the dose of 0.5 and 1.0 mg/kg/day for 7 days significantly suppressed the CCl4-induced increases of alanine transaminase (ALT) and aspartate aminotransferase (AST) levels in serum and meliorated morphological liver injury. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) analysis showed that the number of positive apoptotic hepatocytes in the eckol-treated group was lower than that in the CCl4 model group. Western blotting analysis also demonstrated the enhanced expression of bcl-2 and suppressed expression of cleaved caspase-3 by eckol. The CCl4-induced oxidative stress in liver was significantly ameliorated by eckol, which was characterized by reduced malondialdehyde (MDA) formations, and enhanced superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities and glutathione (GSH) content. Moreover, the CCl4-induced elevations of pro-inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 were markedly suppressed in the eckol-treated group. However, eckol enhanced the level of IL-10, a potent anti-inflammatory cytokine, and recruited CD11c+ dendritic cells into the liver tissues of CCl4-treated mice. These results indicated that eckol has the protective effect on CCl4-induced acute liver injury via multiple mechanisms including anti-apoptosis, anti-oxidation, anti-inflammation and immune regulation.

Apoptosis and non-alcoholic fatty liver diseases.

The number of patients with nonalcoholic fatty liver diseases (NAFLD) including nonalcoholic steatohepatitis (NASH), has been increasing. NASH causes cirrhosis and hepatocellular carcinoma (HCC) and is one of the most serious health problems in the world. The mechanism through which NASH progresses is still largely unknown. Activation of caspases, Bcl-2 family proteins, and c-Jun N-terminal kinase-induced hepatocyte apoptosis plays a role in the activation of NAFLD/NASH. Apoptotic hepatocytes stimulate immune cells and hepatic stellate cells toward the progression of fibrosis in the liver through the production of inflammasomes and cytokines. Abnormalities in glucose and lipid metabolism as well as microbiota accelerate these processes. The production of reactive oxygen species, oxidative stress, and endoplasmic reticulum stress is also involved. Cell death, including apoptosis, seems very important in the progression of NAFLD and NASH. Recently, inhibitors of apoptosis have been developed as drugs for the treatment of NASH and may prevent cirrhosis and HCC. Increased hepatocyte apoptosis may distinguish NASH from NAFLD, and the improvement of apoptosis could play a role in controlling the development of NASH. In this review, the association between apoptosis and NAFLD/NASH are discussed. This review could provide their knowledge, which plays a role in seeing the patients with NAFLD/NASH in daily clinical practice.

Increased hepatic FAT/CD36, PTP1B and decreased HNF4A expression contributes to dyslipidemia associated with ethanol-induced liver dysfunction: Rescue effect of ginger extract.

The association between chronic alcohol consumption and the development of alcpholic liver disease is a very well known phenomenon, but the precise underlying molecular mediators involved in ethanol-induced liver disease remain elusive. This study aimed to characterize the lipid metabolism alterations and the molecular mediators which are related to lipid metabolism in liver under the heavy ethanol exposure alone or combined with ginger extract. Twenty-four male wistar rats were assigned into three groups, namely control, ethanol, and ginger extract treated ethanol (GETE) groups. Six weeks after the treatment, the ethanol group showed a significant increase in fatty acid translocase (FAT)/CD36, protein tyrosine phosphatase 1B (PTP1B) and decrease hepatocyte nuclear factor 4 Alpha (HNF4A) genes expressions compared to the control group. The ethanol administration also significantly increased plasma LDL, cholesterol, triglyceride, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) compared to the control group. Moreover, compared to the control group, the ethanol group showed liver histhological changes, such as fibrosis, focal microvesicular steatosis, some apoptotic hepatocytes, spotty necrosis, portal lymphocytic inflammation, mallory-denk bodies, giant mitochondria, piecemeal necrosis. Consumption of ginger extract along with ethanol, partially ameliorated gene expression alteration and histological changes, improved undesirable lipid profile and liver enzymes changes compare to those in the ethanol group. These findings indicate that ethanol-induced liver abnormalities may in part be associated with lipid homeostasis changes mediated by overexpression of FAT/CD36, PTP1B and downexpressionof HNF4A genes. It also show that these effects can be reduced by using ginger extract as an antioxidant and anti-inflammatory agent.

Effect of long-term immunosuppressive therapy on native rat liver morphology and hepatocyte- apoptosis

A negative result of therapy based on immunosuppressive drugs is its leading to pathological alterations in the organ, including liver. Use of immunosuppressive medication may also lead to organized and genetically controlled cell death – apoptosis. The aim of this study was to examine histopathological changes in the livers of rats treated with immunosuppressive drugs, and also to determine the effects of different groups of immunosuppressive drugs on apoptosis activity in the hepatocytes of rat livers. The study was conducted on archival material obtained from Department of Nephrology, Transplantology and Internal Medicine of the Independent Public Clinical Hospital No. 2 at the Pomeranian Medical University in Szczecin, Poland.Statistical comparison of the treatment groups showed that all groups with rapamycin (sirolimus)-based regimens: Tacrolimus, Rapamycin, Glucocorticosteroid (TRG); Cyclosporine, Rapamycin, Glucocorticosteroid (CRG); Mycophenolate, Rapamycin, Glucocorticosteroid (MRG) and additionally Cyclosporine, Mycophenolate, Glucocorticosteroid (CMG) exhibited significantly more pronounced apoptosis than the control group, with p < 0.01, p < 0.05, p < 0.01 and p < 0.01, respectively. Furthermore, in the TRG group, over 90% of apoptotic hepatocytes were seen in the examined classic lobules. Additionally, every liver from treatment group was pathologically altered, including dilated sinusoids, pyknotic nuclei, swollen walls of the vessels.Long-lasting immunosuppressive treatment affects the liver both in terms of histological changes within the structure of the liver and in terms of the percentage of apoptotic hepatocytes.The following study seems to be very innovating due to the duration of the experiment and used drugs-protocols, since they reflect human treatment.

Complement Factor D protects mice from ethanol-induced inflammation and liver injury.

Complement plays a crucial role in microbial defense and clearance of apoptotic cells. Emerging evidence suggests complement is an important contributor to alcoholic liver disease. While complement component 1, Q subcomponent (C1q)-dependent complement activation contributes to ethanol-induced liver injury, the role of the alternative pathway in ethanol-induced injury is unknown. Activation of complement via the classical and alternative pathways was detected in alcoholic hepatitis patients. Female C57BL/6J [wild type (WT)], C1q-deficient ( C1qa-/-, lacking classical pathway activation), complement protein 4-deficient ( C4-/-, lacking classical and lectin pathway activation), complement factor D-deficient ( FD-/-, lacking alternative pathway activation), and C1qa/FD-/- (lacking classical and alternative pathway activation) mice were fed an ethanol-containing liquid diet or pair-fed control diet for 4 or 25 days. Following chronic ethanol exposure, liver injury, steatosis, and proinflammatory cytokine expression were increased in WT but not C1qa-/-, C4-/-, or C1qa/FD-/- mice. In contrast, liver injury, steatosis, and proinflammatory mediators were robustly increased in ethanol-fed FD-/- mice compared with WT mice. Complement activation, assessed by hepatic accumulation of C1q and complement protein 3 (C3) cleavage products (C3b/iC3b/C3c), was evident in livers of WT mice in response to both short-term and chronic ethanol. While C1q accumulated in ethanol-fed FD-/- mice (short term and chronic), C3 cleavage products were detected after short-term but not chronic ethanol. Consistent with impaired complement activation, chronic ethanol induced the accumulation of apoptotic cells and fibrogenic responses in the liver of FD-/- mice. These data highlight the protective role of complement factor D (FD) and suggest that FD-dependent amplification of complement is an adaptive response that promotes hepatic healing and recovery in response to chronic ethanol. NEW & NOTEWORTHY Complement, a component of the innate immune system, is an important pathophysiological contributor to ethanol-induced liver injury. We have identified a novel role for factor D, a component of the alternative pathway, in protecting the liver from ethanol-induced inflammation, accumulation of apoptotic hepatocytes, and profibrotic responses. These data indicate a dual role of complement with regard to inflammatory and protective responses and suggest that accumulation of apoptotic cells impairs hepatic healing/recovery during alcoholic liver disease.