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Background: Multidrug-resistance protein (MRP) 2 is a key membrane transporter that is expressed on hepatocytes and regulated by nuclear factor kappa B (NF-κB). Interestingly, endoplasmic reticulum (ER) stress is closely associated with liver injury and the activation of NF-κB signaling. Objective: Here, we investigated the impact of ER stress on MRP2 expression and the functional involvement of MRP2 in acute liver injury. Methods: ER stress, MRP2 expression, and hepatocyte injury were analyzed in a carbon tetrachloride (CCl4)-induced mouse model of acute liver injury and in a thapsigargin (TG)-induced model of ER stress. Results: CCl4 and TG induced significant ER stress, MRP2 protein expression and NF- κB activation in mice and LO2 cells (P Conclusion: ER stress enhances intrahepatic MRP2 protein expression by activating NF-κB. This increase in MRP2 expression mitigates ER stress and acute liver injury.

BACKGROUND Acute exacerbation in patients with chronic hepatitis B virus (HBV) infection results in different severities of liver injury. The risk factors related to progression to hepatic decompensation (HD) and acute-on-chronic liver failure (ACLF) in patients with severe acute exacerbation (SAE) of chronic HBV infection remain unknown. AIM To identify risk factors related to progression to HD and ACLF in compensated patients with SAE of chronic HBV infection. METHODS The baseline characteristics of 164 patients with SAE of chronic HBV infection were retrospectively reviewed. Independent risk factors associated with progression to HD and ACLF were identified. The predictive values of our previously established prediction model in patients with acute exacerbation (AE model) and the model for end-stage liver disease (MELD) score in predicting the development of ACLF were evaluated. RESULTS Among 164 patients with SAE, 83 (50.6%) had compensated liver cirrhosis (LC), 43 had progression to HD without ACLF, and 29 had progression to ACLF within 28 d after admission. Independent risk factors associated with progression to HD were LC and low alanine aminotransferase. Independent risk factors for progression to ACLF were LC, high MELD score, high aspartate aminotransferase (AST) levels, and low prothrombin activity (PTA). The area under the receiver operating characteristic of the AE model [0.844, 95% confidence interval (CI): 0.779-0.896] was significantly higher than that of MELD score (0.690, 95%CI: 0.613-0.760, P < 0.05) in predicting the development of ACLF. CONCLUSION In patients with SAE of chronic HBV infection, LC is an independent risk factor for progression to both HD and ACLF. High MELD score, high AST, and low PTA are associated with progression to ACLF. The AE model is a better predictor of ACLF development in patients with SAE than MELD score.

Background. Activating transcription factor 6 (ATF6) and receptor-interacting protein 3 (RIP3) are important signaling proteins in endoplasmic reticulum (ER) stress and necroptosis, respectively. However, their regulatory relationship and clinical significance are unknown. We investigate the impact of ATF6 on RIP3 expression, and its role in hepatocyte necroptosis in an acute liver injury model. Methods. In vivo and in vitro experiments were carried out. LO2 cells were treated with thapsigargin (TG). In vivo, male BALB/c mice were treated with carbon tetrachloride (CCl4, 1 mL/kg) or tunicamycin (TM, 2 mg/kg). Then, the impact of ATF6 or RIP3 silencing on liver injury, hepatocyte necroptosis, and ER stress-related protein expression was examined. Results. TG induced ER stress and necroptosis and ATF6 and RIP3 expression in LO2 cells. The knockdown of ATF6 significantly decreased RIP3 expression ( p < 0.05 ) and increased ER stress and necroptosis. The downregulation of RIP3 significantly reduced necroptosis and ER stress ( p < 0.05 ). Similar results were observed in CCl4 or the TM-induced mouse model. The knockdown of ATF6 significantly decreased CCl4-induced RIP3 expression and increased liver injury, necroptosis, and ER stress in mice livers ( p < 0.05 ). In contrast, the downregulation of RIP3 significantly reduced liver injury, hepatocyte necroptosis, and ER stress. Conclusions. Hepatocyte ATF6 has multiple roles in acute liver injury. It reduces hepatocyte necroptosis via negative feedback regulation of ER stress. In addition, ATF6 can upregulate the expression of RIP3, which is not helpful to the recovery process. However, downregulating RIP3 reduces hepatocyte necroptosis by promoting the alleviation of ER stress. The findings suggest that RIP3 could be a plausible target for the treatment of liver injury.

AIM To investigate the protective effect of prostaglandin E1 (PGE1) against endoplasmic reticulum (ER) stress-induced hepatocyte apoptosis, and to explore its underlying mechanisms. METHODS Thapsigargin (TG) was used to induce ER stress in the human hepatic cell line L02 and hepatocarcinoma-derived cell line HepG2. To evaluate the effects of PGE1 on TG-induced apoptosis, PGE1 was used an hour prior to TG treatment. Activation of unfolded protein response signaling pathways were detected by western blotting and quantitative real-time RT-PCR. Apoptotic index and cell viability of L02 cells and HepG2 cells were determined with flow cytometry and MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay. RESULTS Pretreatment with 1 μmol/L PGE1 protected against TG-induced apoptosis in both L02 cells and HepG2 cells. PGE1 enhanced the TG-induced expression of C/EBP homologous protein (CHOP), glucose-regulated protein (GRP) 78 and spliced X box-binding protein 1 at 6 h. However, it attenuated their expressions after 24 h. PGE1 alone induced protein and mRNA expressions of GRP78; PGE1 also induced protein expression of DNA damage-inducible gene 34 and inhibited the expressions of phospho-PKR-like ER kinase, phospho-eukaryotic initiation factor 2α and CHOP. Treatment with protein kinase A (PKA)-inhibitor H89 or KT5720 blocked PGE1-induced up-regulation of GRP78. Further, the cytoprotective effect of PGE1 on hepatocytes was not observed after blockade of GRP78 expression by H89 or small interfering RNA specifically targeted against human GRP78. CONCLUSION Our study demonstrates that PGE1 protects against ER stress-induced hepatocyte apoptosis via PKA pathway-dependent induction of GRP78 expression.

Aim To investigate the impact of alpha subunit of eukaryotic initiation factor 2 (eIF2α) phosphorylation on liver regeneration. Methods Male BALB/c mice were intraperitoneally injected with carbon tetrachloride (CCl4) to induce liver injury. Human hepatocyte LO2 cells were incubated with thapsigargin to induce endoplasmic reticulum (ER) stress. Salubrinal, integrated stress response inhibitor (ISRIB), and DnaJC3 overexpression were used to alter eIF2α phosphorylation levels. Results CCl4 administration induced significant ER stress and eIF2α phosphorylation, and increased hepatocyte proliferation proportionally to the extent of injury. Inhibiting eIF2α dephosphorylation with salubrinal pretreatment significantly mitigated liver injury and hepatocyte proliferation. In LO2 cells, thapsigargin induced significant eIF2α phosphorylation and inhibited proliferation. Inhibiting eIF2α dephosphorylation partly restored cell proliferation during ER stress. Conclusions In acute liver injury, inhibiting eIF2α dephosphorylation protects injured hepatocytes and reduces hepatocyte proliferation.

Objectives. Protein kinase R-like ER kinase (PERK)/eukaryotic initiation factor 2 alpha (eIF2α) is an important factor along the main pathways for endoplasmic reticulum (ER) stress-mediated apoptosis. In this study, we investigated the effects of eIF2α phosphorylation on hepatocyte apoptosis and the ER stress mechanisms in acute liver injury. Methods. eIF2α phosphorylation and apoptosis under ER stress were monitored and measured in male BALB/c mice with acute liver injury and human hepatocyte line LO2 cells. Results. Carbon tetrachloride (CCl4) administration triggered ER stress and hepatocyte apoptosis, as well as eIF2α phosphorylation in mice. Inhibition of eIF2α dephosphorylation, as the pretreatment with 4-phenylbutyric acid (chemical chaperone, ER stress inhibitor), mitigated CCl4-induced intrahepatic ER stress, apoptosis, and liver injury. In an ER stress model of LO2 cells induced by thapsigargin (disrupting ER calcium balance), inhibition of eIF2α dephosphorylation reduced ER stress and apoptosis, while PERK knockdown reduced eIF2α phosphorylation and exacerbated ER stress and apoptosis. Conclusions. eIF2α phosphorylation is one of the mechanisms employed by ER stress for restoring cellular homeostasis. Inhibition of eIF2α dephosphorylation mitigates hepatocyte apoptosis by alleviating ER stress in acute liver injuries.

Oil absorbing foam as a new type of the oil absorbing material, its oil absorptive property had a very important researching value in oil spill emergency disposal and the treatment of oily wastewater in daily life and laboratory. Polyurethane foam was used as a basal body material and silicone was used as modifier for the surface-modification to an excellent new kind of polyurethane flexible foam. This kind of foam has the quality of high oil-absorbing and low water-absorbing, by changing the potency of silicone and the amount of polyurethane to get the best treatment plan. The results show that the absorption of per gram of this new kind of foam is 16.89g edible oil, 24.86g diesel oil or 26.89g gasoline.

We used surface treatment technology to handle wasted polyurethane foam in this paper. And made out a series of new oil absorbed foams to realize the waste reused. We used the following two technical schemes to improve oil absorption of the polyurethane foam: 1 Dealing polyurethane foam with tung oil;2 Dealing polyurethane foam with tung oil and organic silicon compoundly. Study shows the oil absorbency is up to 22.4 times when using tung oil, at the same time when the concentration of organic silicon is 1:5 , the oil absorbency is 16 times. The oil absorption effect of polyurethane soft foam which experiences the twenty-minute tung oil processing is the best.

The molecular mechanisms of impaired liver regeneration in several liver diseases remain poorly understood. Endoplasmic reticulum (ER) stress has been observed in a variety of liver diseases. The aims of this study were to explore the impacts of ER stress on hepatocyte growth factor (HGF)-induced proliferation and c-Met expression in human hepatocyte L02 cells. Human hepatocyte L02 cells were incubated with thapsigargin (TG) to induce ER stress. 4-Phenylbutyric acid (PBA) was used to rescue ER stress. Activation of glucose-regulated protein 78, phosphorylation of PKR-like ER kinase and eukaryotic translation initiation factor-2α, and the expression of c-Met were determined by western blotting. The expression of c-Met mRNA was observed by reverse transcription polymerase chain reaction. L02 cell proliferation was determined by the MTS assay. L02 cell proliferation was significantly impaired in TG-treated L02 cells from 24 to 48 h, while PBA partly restored the proliferation of L02 cells. In addition, TG treatment significantly decreased the sensitivity of L02 cells to HGF-induced proliferation. PBA partly resumed the sensitivity of L02 cells to HGF-induced proliferation. The expression of c-Met protein in L02 cells was downregulated from 6 h after TG treatment, and PBA partly restored c-Met expression inhibited by TG. The expression of c-Met mRNA was also significantly downregulated from 24 to 48 h after TG treatment. Our results strongly suggest that sustained ER stress inhibits hepatocyte proliferation via downregulation of both c-Met mRNA and protein expression in human hepatocyte L02 cells.

Destrin, also known as actin depolymerizing factor (ADF), is a member of the ADF/Cofilin/destrin superfamily that has the ability to rapidly depolymerize F-actin in a stoichiometric manner. Remodeling of the actin cytoskeleton through actin dynamics (assembly and disassembly of filamentous actin) is known to be essential for numerous basic biological processes including bone formation. The aim of current study was to elucidate whether destrin was involved in the progression of bone loss induced by modeled microgravity. We used the hindlimb suspension (HLS) mice model to simulate microgravity in vivo. Exposure to HLS in mice enhanced femur destrin expression. Destrin deletion in Dstn (-/-) mutant mice enhanced HLS-induced reduction of BMD, ultimate load, stiffness, trabecular thickness, trabecular number, and bone volume fraction in femur, but did not affect them under control static condition. The Rotary wall vessel bioreactor was used to model microgravity in vitro. Exposure to modeled microgravity in cultured 2T3 murine osteoblast precursor cells upregulated destrin expression. RNAi-mediated destrin knockdown enhanced the microgravity-induced reduction of osteoblastic proliferation and differentiation significantly. In conclusion, for the first time we demonstrated that destrin deletion enhances the bone loss in hindlimb suspended mice. Destrin may be a potential target for the prevention or management of microgravity-induced bone loss.

Background Hemophagocytic lymphohistiocytosis (HLH) is a rare condition that can be caused by a primary or acquired disorder of uncontrolled immune response. Liver injury is a common complication of HLH; however, HLH presenting as acute liver failure (ALF) has rarely been reported in adults. Case summary A 34-year-old man was admitted to our hospital with nausea and fatigue persisting for 2 weeks and jaundice for 1 week. He had hyperthermia at the onset of disease. At admission, he had severe liver injury with unknown etiology. The laboratory data showed that he had hyperferritinemia, thrombocytopenia, anemia, hypertriglyceridemia, and hypofibrinogenemia. Finally, a bone marrow biopsy revealed hemophagocytic cells, and he was diagnosed with HLH. The patient was treated with prednisone and plasma exchange. However, the liver function of the patient deteriorated, and he finally died of multiorgan failure. Conclusions Reports of adult patients with ALF caused by HLH have increased, and HLH should be suspected in patients with ALF of indeterminate cause. Although the efficacy of the treatment strategy recommended by the HLH 2004 remains to be confirmed in adult patients with ALF caused by HLH, early diagnosis and prompt combined treatment with steroids and cyclosporin A or etoposide should be emphasized.