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Wen Z.,Tongji University | Wen Z.,Shanghai University | Liu Y.,Capital Medical University | Li F.,Baylor College of Medicine | And 7 more authors.
Journal of Cellular Biochemistry | Year: 2013

Circulating histones are a newly recognized mediator implicated in various inflammatory diseases. It is likely that the release of histones, from dying hepatocytes or inflammatory leukocytes, into the circulation initiates and amplifies inflammation during the course of acute liver failure (ALF). In this study, we investigated a putative pathogenic role of circulating histones in a murine model of ALF induced by D-galactosamine (GalN) plus lipopolysaccharide (LPS). Hepatic function and histological indexes, myeloperoxidase (MPO) activity, hepatocyte apoptosis and the levels of circulating histone were measured in GalN/LPS-treated mice. GalN/LPS caused severe liver damage and a notable increase in plasma concentration of circulating histones. To further assess the role of circulating histones in our model, we administered exogenous histones and anti-histone H4 antibody. Notably, exogenous histones aggravated GalN/LPS-induced hepatotoxicity, whereas anti-histone antibody significantly protected mice. Circulating histones may serve as both a functional marker of ALF activity and as an inflammatory mediator contributing to the progression of ALF. Blockade of circulating histones shows potent protective effects, suggesting a potential therapeutic strategy for ALF. J. Cell. Biochem. 114: 2384-2391, 2013. © 2013 Wiley Periodicals, Inc. Copyright © 2013 Wiley Periodicals, Inc.


Shi Y.,Capital Medical University | Shi Y.,Beijing Institute of Hepatology | Han Y.,University of Jinan | Xie F.,Beijing Institute of Hepatology | And 8 more authors.
Journal of Cellular and Molecular Medicine | Year: 2015

Inactivation of p53-mediated cell death pathways is a central component of cancer progression. ASPP2 (apoptosis stimulated protein of p53-2) is a p53 binding protein that specially stimulates pro-apoptosis function of p53. Down-regulation of ASPP2 is observed in many human cancers and is associated with poor prognosis and metastasis. In this study, ASPP2 was found to enhance L-OHP-induced apoptosis in HCT116 p53-/- cells in a p53-independent manner. Such apoptosis-promoting effect of ASPP2 was achieved by inhibiting autophagy. Further experiments with ASPP2 RNA interference and autophagy inhibitor (3-methyladenine, 3-MA) confirmed that ASPP2 enhanced HCT116 p53-/- cell apoptosis via inhibiting the autophagy. The association of cell death and autophagy was also found in ASPP2+/- mice, where colon tissue with reduced ASPP2 expression displayed more autophagy and less cell death. Finally, colorectal tumours and their adjacent normal tissues from 20 colorectal cancer patients were used to examine ASPP2 expression, p53 expression and p53 mutation, to understand their relationships with the patients' outcome. Three site mutations were found in p53 transcripts from 16 of 20 patients. ASPP2 mRNA expressions were higher, and autophagy level was lower in the adjacent normal tissues, compared with the tumour tissues, which was independent of both p53 mutation and expression level. Taken together, ASPP2 increased tumour sensitivity to chemotherapy via inhibiting autophagy in a p53-independent manner, which was associated with the tumour formation, suggesting that both p53 inactivation and ASPP2 expression level were involved in the sensitivity of colorectal cancer to chemotherapy. © 2014 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.


Liu K.,Capital Medical University | Liu K.,Beijing Institute of Hepatology | Lou J.,Capital Medical University | Lou J.,Beijing Institute of Hepatology | And 16 more authors.
Liver International | Year: 2013

Background & Aims: Apoptosis mediated by p53 plays a pathological role in the progression of hepatosteatosis. It is noteworthy that p53 can promote the expression of damage-regulated autophagy modulator (DRAM), an inducer of autophagy-mediated apoptosis. However, the relationship between p53-mediated apoptosis and autophagy in hepatosteatosis remains elusive. This study aimed to examine how p53 orchestrates autophagy and apoptosis to affect hepatosteatosis. Methods: HepG2 cells were treated with oleic acid (OA) for 24 h to induce hepatosteatosis. Mice were fed a high-fat diet for 20 or 40 weeks to induce hepatosteatosis. Results: OA induced a dose-dependent increase in steatosis severity and apoptosis. OA also induced autophagy, which was a critical inducer of apoptosis in mild steatosis induced by 400 μM OA, but not in the more severe steatosis induced by 800 and 1200 μM OA. p53 inhibition by siRNA mostly blocked OA-induced apoptosis and autophagy. Moreover, OA-induced autophagy was DRAM-dependent and primarily occurred in the mitochondria (mitophagy), where DRAM was localized. In severe steatosis induced by 1200 μM OA, apoptosis was mainly dependent on p53-induced expression of BAX, which was also localized to the mitochondria. Our in vivo study showed that p53 expression increased in both mild and severe hepatosteatosis. Increased DRAM expression and autophagy were identified in mild hepatosteatosis, whereas greater BAX expression was observed in severe hepatosteatosis. Conclusions: p53 may induce apoptosis via different mechanisms. DRAM-mediated mitophagy is a primary apoptotic inducer in mild hepatosteatosis, whereas p53-induced BAX expression mainly induces apoptosis in severe hepatosteatosis. © 2013 The Authors.


Ouyang Y.,Capital Medical University | Ouyang Y.,Beijing Institute of Hepatology | Liu L.,Capital Medical University | Liu L.,Beijing Institute of Hepatology | And 14 more authors.
Journal of NeuroVirology | Year: 2014

The genetic evolution of HIV-1 in the central nervous system (CNS) is different from that in peripheral tissues. We analyzed 121 clonal sequences of the V3-V5 regions of the env gene generated from paired cerebrospinal fluid (CSF) and plasma samples from nine chronically infected patients (four with HIV-associated neurocognitive disorder (HAND) and five without HAND). The sequence analysis indicated the significant differences between CSF and plasma was only observed in the C4 region (P=0.043) in HAND patients. Significant increases in synonymous substitutions (dS) within the V4 region (P=0.020) and in nonsynonymous substitutions (dN) within the C4 region (P=0.029) were observed in the CSF-derived sequences. By contrast, CSF-derived sequences from non-HAND patients showed similar levels of diversity; dS and dN as the plasma-derived sequences. Signature differences between the CSF- and plasma-derived sequences were found at 12 amino acid positions for HAND patients and nine positions for non-HAND patients. Interestingly, five sites (positions 388, 396, 397, 404, and 406) that all belong to signature patterns exhibited positive selection pressure in CSF samples, but only site 406 was positively selected in the plasma samples from the HAND patients. Conversely, in the non-HAND patients, there were four sites (positions 397, 404, 432, and 446) showed positive selection pressure in the plasma samples, but only site 446 in the CSF samples. These results suggest that discordant patterns of genetic evolution occur between the tissue-specific HIV-1 quasispecies in the HAND and non-HAND patients. Viral molecular heterogeneity between specific tissues is greater in patients with HAND compared to non-HAND patients. © 2014 Journal of NeuroVirology, Inc.


Liu K.,Beijing Institute of Hepatology | Liu K.,Capital Medical University | Shi Y.,Beijing Institute of Hepatology | Shi Y.,Capital Medical University | And 12 more authors.
Cell Death and Disease | Year: 2014

Increasing autophagy is beneficial for curing hepatocellular carcinoma (HCC). Damage-regulated autophagy modulator (DRAM) was recently reported to induce apoptosis by mediating autophagy. However, the effects of DRAM-mediated autophagy on apoptosis in HCC cells remain unclear. In this study, normal hepatocytes (7702) and HCC cell lines (HepG2, Hep3B and Huh7) were starved for 48 h. Starvation induced apoptosis and autophagy in all cell lines. We determined that starvation also induced DRAM expression and DRAM-mediated autophagy in both normal hepatocytes and HCC cells. However, DRAM-mediated autophagy was involved in apoptosis in normal hepatocytes but not in HCC cells, suggesting that DRAM-mediated autophagy fails to induce apoptosis in hepatoma in response to starvation. Immunoblot and immunofluorescence assays demonstrated that DRAM translocated to mitochondria and induced mitophagy, which led to apoptosis in 7702 cells. In HCC cells, starvation also activated the phosphatidylinositol 3-kinase (PI3K)/AKT pathway, which blocks the translocation of DRAM to mitochondria through the binding of p-AKT to DRAM in the cytoplasm. Inactivation of the PI3K/AKT pathway rescued DRAM translocation to mitochondria; subsequently, mitochondrial DRAM induced apoptosis in HCC cells by mediating mitophagy. Our findings open new avenues for the investigation of the mechanisms of DRAM-mediated autophagy and suggest that promoting DRAM-mediated autophagy together with PI3K/AKT inhibition might be more effective for autophagy-based therapy in hepatoma. © 2014 Macmillan Publishers Limited.


Liu K.,Capital Medical University | Liu K.,Beijing Institute of Hepatology | Shi Y.,Capital Medical University | Shi Y.,Beijing Institute of Hepatology | And 15 more authors.
Cell Death and Disease | Year: 2014

Apoptosis-stimulating protein of p53-2 (ASPP2) induces apoptosis by promoting the expression of pro-apoptotic genes via binding to p53 or p73; however, the exact mechanisms by which ASPP2 induces apoptotic death in hepatoma cells are still unclear. Here, we show that the transient overexpression of ASPP2 induces autophagic apoptosis in hepatoma cells by promoting p53- or p73-independent C/EBP homologous protein (CHOP) expression. CHOP expression decreases the expression of Bcl-2; this change releases Beclin-1 from cytoplasmic Bcl-2-Beclin-1 complexes and allows it to initiate autophagy. However, transient overexpression of Beclin-1 can induce autophagy but not apoptosis. Our results show that ASPP2 induces the expression of damage-regulated autophagy modulator (DRAM), another critical factor that cooperates with free Beclin-1 to induce autophagic apoptosis. The effect of CHOP on the translocation and sequestration of Bcl-2 in the nucleus, which requires the binding of Bcl-2 to ASPP2, is also critical for ASPP2-induced autophagic apoptosis. Although the role of nuclear ASPP2-Bcl-2 complexes is still unclear, our results suggest that nuclear ASPP2 can prevent the translocation of the remaining Bcl-2 to the cytoplasm by binding to Bcl-2 in a CHOP-dependent manner, and this effect also contributes to Beclin-1-initiated autophagy. Thus, CHOP is critical for mediating ASPP2-induced autophagic apoptosis by decreasing Bcl-2 expression and maintaining nuclear ASPP2-Bcl-2 complexes. Our results, which define a mechanism whereby ASPP2 overexpression induces autophagic apoptosis, open a new avenue for promoting autophagy in treatments to cure hepatocellular carcinoma. © 2014 Macmillan Publishers Limited All rights reserved 2041-4889/14.


Li X.,Capital Medical University | Gou C.,Capital Medical University | Yang H.,Capital Medical University | Qiu J.,Capital Medical University | And 3 more authors.
Scandinavian Journal of Gastroenterology | Year: 2014

Objective. This study aimed to investigate the protective effects of echinacoside, one of the phenylethanoids isolated from the stems of Cistanche salsa, a Chinese herbal medicine, on D-galactosamine (GalN) and lipopolysaccharide (LPS)-induced acute liver injury in mice. Methods. We administered GalN (650 mg/kg) together with LPS (30 μg/kg) to mice by intraperitoneal injection to induce acute liver damage. Echinacoside (60 mg/kg) was given intraperitoneally to mice at 1 h prior to GalN/LPS exposure. Mice were sacrificed at different time points following GalN/LPS treatment, and the liver and blood samples were collected for future analysis. Results. It showed that GalN/LPS treatment produced severe hepatic injury, evidenced by significantly elevated plasma alanine aminotransferase (ALT) levels and abnormal histological changes such as hepatocyte necrosis or apoptosis, hemorrhage, fatty degeneration, and neutrophil infiltration. Notably, pretreatment with echinacoside remarkably improved the survival rate of GalN/LPS-treated mice and attenuated acute hepatotoxicity, as demonstrated by decreased ALT levels and improved histological signs. Echinacoside shows both anti-apoptotic and anti-inflammatory properties, characterized by a substantial inhibition of hepatocyte apoptosis and a significant reduction in the inflammatory markers, including myeloperoxidase, extracellular nucleosomes, high-mobility group box 1, and inflammatory cytokines in the plasma of mice, which may be important mechanisms related to its protective effect. Conclusion. Our results suggest that echinacoside can provide a pronounced protection against GalN/LPS-induced acute liver injury in mice, which may complement the available strategies for management of acute liver damage in clinical settings. © 2014 Informa Healthcare.


Chen L.-Y.,Harbin Medical University | Yang B.,Harbin Medical University | Zhou L.,Capital Medical University | Ren F.,Capital Medical University | And 3 more authors.
Molecular Medicine Reports | Year: 2015

Hepatocyte apoptosis and energy metabolism in mitochondria have an important role in the mechanism of acute liver failure (ALF). However, data on the association between apoptosis and the energy metabolism of hepatocytes are lacking. The current study assessed the activity of several key enzymes in mitochondria during ALF, including citrate synthase (CS), carnitine palmitoyltransferase-1 (CPT-1) and cytochrome c oxidase (COX), which are involved in hepatocyte energy metabolism. A total of 40 male Sprague-Dawley rats were divided into five groups and administered D-galactosamine and lipopolysaccharide to induce ALF. Hepatic pathology and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling examinations indicated that hepatocyte apoptosis was observed at 4 h and increased 8 h after ALF. Hepatocyte necrosis appeared at 12 h and was significantly higher at 24 h with inflammatory cell invasion. The results measured by electron microscopy indicated that ultrastructural changes in mitochondria began at 4 h and the mitochondrial outer membrane was completely disrupted at 24 h resulting in mitochondrial collapse. The expression of CS, CPT-1 and COX was measured and analyzed using assay kits. The activity and protein expression of CS, CPT-1 and COX began to increase at 4 h, reached a peak at 8 h and decreased at 12 h during ALF. The activities of CS, CPT-1 and COX were enhanced during hepatocyte apoptosis suggesting that these enzymes are involved in the initiation and development of ALF. Therefore, these results demonstrated that energy metabolism is important in hepatocyte apoptosis during ALF and hepatocyte apoptosis is an active and energy-consuming procedure. The current study on how hepatocyte energy metabolism affects the transmission of death signals may provide a basis for the early diagnosis and development of an improved therapeutic strategy for ALF.


PubMed | Capital Medical University and Beijing Institute of Hepatology
Type: | Journal: Cell death & disease | Year: 2014

Increasing autophagy is beneficial for curing hepatocellular carcinoma (HCC). Damage-regulated autophagy modulator (DRAM) was recently reported to induce apoptosis by mediating autophagy. However, the effects of DRAM-mediated autophagy on apoptosis in HCC cells remain unclear. In this study, normal hepatocytes (7702) and HCC cell lines (HepG2, Hep3B and Huh7) were starved for 48h. Starvation induced apoptosis and autophagy in all cell lines. We determined that starvation also induced DRAM expression and DRAM-mediated autophagy in both normal hepatocytes and HCC cells. However, DRAM-mediated autophagy was involved in apoptosis in normal hepatocytes but not in HCC cells, suggesting that DRAM-mediated autophagy fails to induce apoptosis in hepatoma in response to starvation. Immunoblot and immunofluorescence assays demonstrated that DRAM translocated to mitochondria and induced mitophagy, which led to apoptosis in 7702 cells. In HCC cells, starvation also activated the phosphatidylinositol 3-kinase (PI3K)/AKT pathway, which blocks the translocation of DRAM to mitochondria through the binding of p-AKT to DRAM in the cytoplasm. Inactivation of the PI3K/AKT pathway rescued DRAM translocation to mitochondria; subsequently, mitochondrial DRAM induced apoptosis in HCC cells by mediating mitophagy. Our findings open new avenues for the investigation of the mechanisms of DRAM-mediated autophagy and suggest that promoting DRAM-mediated autophagy together with PI3K/AKT inhibition might be more effective for autophagy-based therapy in hepatoma.


PubMed | Capital Medical University and Beijing Institute of Hepatology
Type: Case Reports | Journal: Epidemiology and infection | Year: 2015

Hepatitis G virus or GB virus C (GBV-C) is a human virus of the Flaviviridae family that is structurally and epidemiologically closest to hepatitis C virus, but replicates primarily in lymphocytes. Co-infection with GBV-C has been reported to confer beneficial outcomes in some HIV-positive patients. Up to now, however, studies on GBV-C infection in the central nervous system (CNS) of HIV-infected patient have rarely been reported. Herein, we report on a 32-year-old HIV-1-infected patient with cerebral toxoplasmosis and fungal encephalitis. GBV-C viral loads were detected in CSF by quantitative real-time reverse transcription polymerase chain reaction (RT-PCR), and the results showed that GBV-C viral load was 65 log copies/ml. We amplified and sequenced the E2 and 5-untranslated regions from the purified viral RNA from CSF by RT-PCR. Both sequences belong to genotype 3 and there were some minor nucleotide divergence among the E2 sequences from the CSF of the patient. These data suggest that GBV-C may be able to penetrate the blood-brain barrier and colonize the CNS of HIV-infected patients. However, the exact mechanisms and potential effect of the infected GBV-C in CNS on HIV-associated neuropathy needs to be further explored.

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