[Role of endoplasmic reticulum stress-mediated glycogen synthase kinase 3β activity in pathogenesis of acute liver failure in mice]

Objective: To study the role of endoplasmic reticulum (ER) stress-mediated glycogen synthase kinase 3β (GSK3β) activity in the pathological process of liver injury in acute liver failure (ALF) mice. Methods: ALF model was established by intraperitoneal injection of D-galactosamine/lipopolysaccharide (D-GalN/LPS) in C57BL/6 mice. The mice were divided into control group (n=10), ALF model group (n=18), 4-phenylbutyrate (4-PBA, an ER stress inhibitor) group (n=18) and SB216763 (a specific inhibitor of GSK3β) group (n=16). The serum alanine transaminase (ALT) and aspartate transaminase (AST) levels were measured to reflect the liver function, liver injury was assessed by observing pathological changes of liver tissue, the levels of proteins in liver tissue were analyzed by Western blotting, the activity of GSK3β in liver tissue was detected using GSK3β activity assay kit, and the survival rate of hepatocyte was measured by methyl thiazolyl tetrazolium (MTT) assay. Results: In in vivo experiment, the expression levels of ER stress markers, glucose-regulated protein 78 (GRP78) and CCAAT/enhancer-binding protein homologous protein (CHOP), were upregulated during the progression of D-GalN/LPS-induced ALF, indicating activation of severe ER stress and increased activity of GSK3β. Compared with the model group, inhibition of ER stress by 4-PBA improved liver function[ALT: (365.4±58.6) U/L vs (1 094.5±201.5) U/L, P<0.05; AST: (555.1±60.8) U/L vs (1 444.3±533.7) U/L, P<0.05)and pathological injury, also decreased the activity of GSK3β (2.6±0.3 vs 4.6±1.3, P<0.05). Inhibition of GSK3β activity was shown to alleviate liver injury in ALF by reducing the expression levels of GRP78 and CHOP. The in vitro experiment of tunicamycin-induced hepatocyte apoptosis showed that inhibition of GSK3β activity increased the cell survival rate. Conclusion: In ALF induced by D-GalN/LPS, severe ER stress may accelerate the development and progress of ALF by upregulating the activity of GSK3β.

Impact of carbohydrates on autoinducer-2 secretion of Bifidobacterium longum subsp. longum BBMN68

In this study, the regularity of autoinducer-2 (AI-2) secretion during growth and the effect of the addition of various carbohydrates on AI-2 secretion in Bifidobacterium longum subsp. longum BBMN68 were investigated. The results indicated that the AI-2 concentration reached its highest level (2536·60 nmol l^-1 ) at the early stationary growth phase, and then decreased to 1263·72 nmol l^-1 at the late stationary growth phase in Bifidobacterium cultures. When the density of the cultures which mannose, fructose, sucrose and lactose had been added to reached an OD_600 nm of 1·0, the AI-2 concentrations in the cultures were 1953·84, 1637·34, 1200·99 and 1077·60 nmol l^-1 , respectively. These concentrations were all significantly higher than that of the control culture (1031·33 nmol l^-1 ). Similarly, the addition of fructooligosaccharide significantly increased the AI-2 concentrations to 2094·29 nmol l^-1 . This study provides the advanced evidence that certain carbohydrates promote the secretion of AI-2, and that this occurs at the single cell level and is therefore unaffected by cell density.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provided the advanced data of the regularity of autoinducer-2 (AI-2) secretion during growth and the promotion on AI-2 secretion of different added carbohydrates in Bifidobacterium, which may be a new potential strategy to improve the acid resistance of Bifidobacterium applied in the food industry.

Randomized clinical study of wear of enamel antagonists against polished monolithic zirconia crowns

OBJECTIVES

To test the hypothesis that there is no difference in the in vivo maximum wear of enamel opposing monolithic zirconia crowns, enamel opposing porcelain fused to metal crowns and enamel opposing enamel.

METHODS

Thirty patients needing single crowns were randomized to receive either a monolithic zirconia or metal-ceramic crown. Two non-restored opposing teeth in the same quadrants were identified to serve as enamel controls. After cementation, quadrants were scanned for baseline data. Polyvinylsiloxane impressions were obtained and poured in white stone. Patients were recalled at six-months and one-year for re-impression. Stone models were scanned using a tabletop laserscanner to determine maximum wear. Statistical analysis was performed using Mann-Whitney U to determine any significant differences between the wear of enamel against zirconia and metal-ceramic crowns.

RESULTS

Sixteen zirconia and 14 metal-ceramic crowns were delivered. There were no statistical differences in mean wear of crown types (p=0.165); enamel antagonists (p=0.235) and enamel controls (p=0.843) after one year.

CONCLUSION

Monolithic zirconia exhibited comparable wear of enamel compared with metal-ceramic crowns and control enamel after one year.

SIGNIFICANCE

This study is clinically significant because the use of polished monolithic zirconia demonstrated comparable wear of opposing enamel to metal-ceramic and enamel antagonists.

[Protective effect of glycogen synthase kinase 3β inhibition via peroxisome proliferator-activated receptor alpha activation in mice with acute liver failure]

Objective: To investigate the role of the glycogen synthase kinase 3β (GSK3β) and the peroxisome proliferator-activated receptor alpha (PPARα) signaling pathway in acute liver failure and related mechanisms in a mouse model of acute liver failure induced by D-galactosamine/lipopolysaccharide (D-GalN/LPS). Methods: C57BL/6 mice were given intraperitoneal injection of D-GalN/LPS to establish a mouse model of acute liver failure. SB216763 was used to inhibit the activity of GSK3β and PPARα siRNA was used to inhibit the expression of PPARα. Western blotting was used to measure the expression of PPARα protein. The changes in liver pathology were observed to evaluate liver injury, and the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured to assess liver function. Quantitative real-time PCR was used to measure the mRNA expression of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-12p40 (IL-12p40), and PPARα. A one-way analysis of variance was used for comparison of means between multiple groups; the least significant difference test was used for data with homogeneity of variance, and the Games-Howell method was used for data with heterogeneity of variance. Results: In the mice with liver failure induced by D-GalN/LPS, GSK3β inhibition promoted the mRNA and protein expression of PPARα (F = 13.18 and 301.36, P = 0.00 and 0.00). In the mice with acute liver failure induced by D-GalN/LPS, GSK3β inhibition alleviated liver bleeding, inflammation, and necrosis and reduced the serum levels of ALT (F = 25.16, P = 0.000) and AST (F = 12.96, P = 0.001), as well as the mRNA expression of TNF-α (F = 32.17, P = 0.00), IL-1β (F = 11.57, P = 0.005), and IL-12p40 (F = 14.17, P = 0.015) in liver tissue. The inhibition of PPARα expression reversed the liver-protecting effect of GSK3β inhibition, which manifested as aggravation in liver bleeding, inflammation, and necrosis, increases in the serum levels of ALT (F = 25.16, P = 0.001) and AST (F = 12.96, P = 0.000), and an increase in the mRNA expression of TNF-α (F = 32.17, P = 0.00), IL-1β (F = 11.57, P = 0.024), and IL-12p40 (F = 14.17, P = 0.001) in liver tissue. Conclusion: In mice with acute liver failure induced by D-GalN/LPS, the GSK3β-PPARα-inflammatory factor signaling pathway may play an important role. GSK3β inhibition has a protective effect in mice with acute liver failure possibly by activating the inhibitory inflammatory factor of PPARα.

[Cellular and molecular mechanisms of anti-inflammatory effect of peroxisome proliferator-activated receptor α]

Objective: To investigate the cellular and molecular mechanisms of the anti-inflammatory effect of peroxisome proliferator-activated receptor α (PPARα). Methods: Firstly, bone marrow-derived macrophages (BMDMs) were randomly divided into control group, LPS group, WY14643 10 μmol/L group, WY14643 25 μmol/L group, and WY14643 50 μmol/L group using a random number table. Secondly, BMDMs were randomly divided into LPS group, WY14643+LPS group, and 3-MA+WY14643+LPS group. Primary BMDMs were stimulated by LPS (20 ng/ml) to establish the cellular model of inflammation. The selective agonist of PPARα WY14643 was administered at doses of 10, 25, and 50 μmol/L (50 μmol/L for the second part of the experiment) at 2 hours before model establishment. The autophagy inhibitor 3-MA was administered at a dose of 10 mmol/L at 2 hours before model establishment. The cells in the control group were treated with dimethylsulfoxide (DMSO) at the same dose. The cells were transfected with GFP-LC3 plasmids at 24 hours before model establishment. The cells were harvested at 6 hours after LPS stimulation and related tests were performed. Green fluorescent protein was measured under a fluorescence microscope to evaluate autophagy activity. Quantitative real-time PCR was used to measure tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and mRNA expression of chemokine-1 (CXCL-1) and chemokine-10 (CXCL-10). Western blot was used to measure PPARα and autophagy-related proteins LC3, ATG-5, ATG-7, and LAMP-1. A one-way analysis of variance was used for comparison between groups, and the LSD-t test was used for comparison between any two groups. Results: In vitro, PPARα activation inhibited LPS-induced inflammatory response in primary macrophages in a dose-dependent manner. The results of gene expression showed that the relative expression of TNF-α, IL-1β, IL-6, CXCL-1, and CXCL-10 was as follows in the control group, LPS group, WY14643 10 μmol group, WY14643 25 μmol group, and WY14643 50 μmol group: TNF-α (0.085±0.009, 4.065±0.544, 3.281±0.368, 1.780±0.293, and 0.781±0.303, P < 0.01), IL-1β (0.081±0.017, 0.776±0.303, 0.225±0.154, 0.161±0.068, and 0.101±0.025, P < 0.05), IL-6 (0.041±0.011, 0.189±0.014, 0.144±0.033, 0.126±0.013, and 0.048±0.015, P < 0.01), CXCL-1 (0.051±0.011, 0.515±0.145, 0.356±0.078, 0.257±0.068, and 0.069±0.030, P < 0.01), and CXCL-10 (0.126±0.068, 0.831±0.093, 0.508±0245, 0.474±0.047, and 0.204±0.021, P < 0.05). In vitro, PPARα activation promoted autophagy in vitro in a dose-dependent manner. The results of Western blot and fluorescence microscopy in the control group, LPS group, WY14643 10 μmol group, WY14643 25 μmol group, and WY14643 50 μmol group showed that the expression of autophagy-related proteins and autophagosome formation gradually increased with the increasing concentration of WY14643. In vitro, WY14643 inhibited autophagy, promoted inflammatory response in primary macrophages, and reversed the anti-inflammatory effect of PPARα. The results of gene expression showed that the relative expression of TNF-α, IL-1β, IL-6, CXCL-1, and CXCL-10 was as follows in the LPS group, WY14643+LPS group, and 3-MA+WY14643+LPS group: TNFα (4.327±0.478, 1.218±0.424, and 3.901±0.447, P < 0.05), IL-1β (4.277±0.407, 1.418±0.424, and 3.029±0.192, P < 0.01), IL-6 (4.175±0.549, 1.373±0.499, and 4.031±0.475, P < 0.05), CXCL-1 (8.199±1.149, 2.024±0.547, and 5.973±0.843, P < 0.05), and CXCL-10 (1.208±0.148, 0.206±0.069, and 0.798±0.170, P < 0.05). Conclusion: PPARα can promote cell autophagy and inhibit inflammatory response and may become a new therapeutic target for clinical prevention and treatment of inflammatory disease.

Novel Testing for Corrosion of Glass-Ceramics for Dental Applications

The effects of pH cycling immersion on the corrosion of glass-based ceramic materials were investigated by examining the silicon release level in the immersion solution and the surface morphology of the ceramic after immersion. The hypothesis that pH cycling causes more surface degradation than constant immersion was tested. An inductively coupled plasma atomic emission spectrometer was used for Si ion concentration determination and scanning electron microscopy for surface morphology analyses. Two pH cycling sequences (pH 2, 7, 10 and pH 10, 2, 7) were employed in this study. Glass-ceramic disks were immersed in each pH solution for 3 d, then cycled for 27 d. The silicon release levels during the pH cycling were significantly higher than those in the constant pH immersion. The silicon levels for both cycling sequences were around 47 and 2 times higher than that in constant pH conditions for 2 and 10, respectively. The morphology of the ceramic treated with cycling was also significantly degraded as compared with the ceramic immersed in the constant pH solution. Thus, the severity of glass-ceramic degradation depends not only on the pH of the immersed solution but also on the pH of the previous solution. Since the pH of the oral environment can vary depending on the diet and buffering capacity of saliva, materials testing in constant pH immersion might underestimate the in vivo corrosion. New mechanisms were proposed to account for the effect of pH cycling on glass-ceramic corrosion.

CHIP/Stub1 regulates the Warburg effect by promoting degradation of PKM2 in ovarian carcinoma

Tumor cells preferentially adopt aerobic glycolysis for their energy supply, a phenomenon known as the Warburg effect. It remains a matter of debate as to how the Warburg effect is regulated during tumor progression. Here, we show that CHIP (carboxyl terminus of Hsc70-interacting protein), a U-box E3 ligase, suppresses tumor progression in ovarian carcinomas by inhibiting aerobic glycolysis. While CHIP is downregulated in ovarian carcinoma, induced expression of CHIP results in significant inhibition of the tumor growth examined by in vitro and in vivo experiments. Reciprocally, depletion of CHIP leads to promotion of tumor growth. By a SiLAD proteomics analysis, we identified pyruvate kinase isoenzyme M2 (PKM2), a critical regulator of glycolysis in tumors, as a target that CHIP mediated for degradation. Accordingly, we show that CHIP regulates PKM2 protein stability and thereafter the energy metabolic processes. Depletion or knockout of CHIP increased the glycolytic products in both tumor and mouse embryonic fibroblast cells. Simultaneously, we observed that CHIP expression inversely correlated with PKM2 levels in human ovarian carcinomas. This study reveals a mechanism that the Warburg effect is regulated by CHIP through its function as an E3 ligase, which mediates the degradation of PKM2 during tumor progression. Our findings shed new light into understanding of ovarian carcinomas and may provide a new therapeutic strategy for ovarian cancer.

Patients with HBV-related acute-on-chronic liver failure have increased concentrations of extracellular histones aggravating cellular damage and systemic inflammation

Acute-on-chronic liver failure (ACLF) is the most common type of liver failure and associated with grave consequences. Systemic inflammation has been linked to its pathogenesis and outcome, but the identifiable triggers are absent. Recently, extracellular histones, especially H4, have been recognized as important mediators of cell damage in various inflammatory conditions. This study aimed to investigate whether extracellular histones have clinical implications in patients with hepatitis B virus (HBV)-related ACLF. One hundred and twelve patients with HBV-related ACLF, 90 patients with chronic hepatitis B, 88 patients with HBV-related liver cirrhosis and 40 healthy volunteers were entered into this study. Plasma histone H4 levels, cytokine profile and clinical data were obtained. Besides, patient's sera were incubated overnight with human L02 hepatocytes or monocytic U937 cells in the presence or absence of antihistone H4 antibody, and cellular damage and cytokine production were evaluated. We found that plasma histone H4 levels were greatly increased in patients with ACLF as compared with chronic hepatitis B, liver cirrhosis and healthy control subjects and were significantly associated with disease severity, systemic inflammation and outcome. Notably, ACLF patients' sera incubation decreased cultured L02 cell integrity and induced profound cytokine production in the supernatant of U937 cells. Antihistone H4 antibody treatment abrogated these adverse effects, thus confirming a cause-effect relationship between extracellular histones and organ injury/dysfunction. The data support the hypothesis that the increased extracellular histone levels in ACLF patients may aggravate disease severity by inducing cellular injury and systemic inflammation. Histone-targeted therapies may have potentially interventional value in clinical practice.

Occurrence and Genetic Diversity of Grapevine berry inner necrosis virus from Grapevines in China

To investigate the prevalence and genetic diversity of Grapevine berry inner necrosis virus (GINV) in China, 195 grapevine samples from 15 Chinese provinces and regions were tested using reverse-transcription polymerase chain reaction. The samples included symptomatic and asymptomatic cultivars, with 35.9% (70 of 195) of samples testing positive for GINV. Seventeen samples had obvious ring spot symptoms, and 94.1% (16 of 17) tested positive for GINV, suggesting that GINV may be highly associated with the ring spot symptom. The genetic diversity of GINV isolates was analyzed based on the partial nucleotide and amino acid sequences of the coat protein (CP) and movement protein (MP) genes. Phylogenetic analyses of the MP and CP gene sequences divided the GINV isolates into three groups. The majority of the Chinese isolates were in groups 1 and 2, and only one Chinese isolate, along with a previously reported Japanese isolate, was in group 3. This is the first report on the genetic diversity of GINV isolates and their prevalence and distribution in China.

[Augmenter of liver regeneration promotes the proliferation of HL-7702 cells in carbon tetrachloride-induced acute liver injury via increasing autophagy]

Objective: To investigate the protective effect of augmenter of liver regeneration (ALR) against acute liver injury and related mechanisms. Methods: HL-7702 cells were divided into normal control group, carbon tetrachloride (CCl₄)-induced acute liver injury group, ALR+CCl₄ intervention group, 3-methyladenine (3-MA)+CCl₄ intervention group, and ALR+3-MA+CCl₄ intervention group. The ALR+CCl₄ and ALR+3-MA+CCl₄ intervention groups were transfected with ALR plasmids at 8 hours before CCl₄ treatment. All groups except the normal control group were treated with CCl₄, and 30 minutes later, the 3-MA+CCl₄ and ALR+3-MA+CCl₄ intervention groups were treated with 3-MA. The cells were collected at 24 hours after CCl₄ treatment. The HL-7702 cells and supernatant were collected to measure the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) (IU/L). Western blot was used to measure the levels of ALR, cyclin D, cyclin E, proliferating cell nuclear antigen (PCNA), autophagy-related gene 7 (Atg7), and autophagy genes LC3, p62, and Beclin-1. Quantitative real-time PCR was used to measure the mRNA expression of ALR. A one-way analysis of variance was used for comparison of means between any two groups. Results: The ALR+CCl₄ intervention group had significant increases in the protein and mRNA expression of ALR compared with the acute liver injury group (both P < 0.05). The CCl₄-induced acute liver injury group had significant increases in the protein and mRNA expression of ALR compared with the normal control group (both P < 0.05). Compared with the CCl₄-induced acute liver injury group, the ALR+CCl₄ intervention group had significant reductions in ALT (0.73±0.17 IU/L vs 1.43±0.38 IU/L, P < 0.05) and AST (19.85±1.83 IU/L vs 56.73±6.25 IU/L, P < 0.05) in supernatant, significantly increased expression of cyclin D, cyclin E, PCNA, LC3, Atg7, and Beclin-1 in hepatocytes, and significantly reduced expression of p62, which suggested that ALR protected the liver against acute liver injury, promoted the regeneration of hepatocytes, and enhanced the autophagy of hepatocytes. The ALR+3-MA+CCl₄ intervention group had a significant reduction in the expression of regeneration-associated proteins compared with the ALR+CCl₄ intervention group, while there was no significant difference between the ALR+3-MA+CCl₄ intervention group and 3-MA+CCl₄ intervention group, which suggested that after the inhibition of autophagy, there were significant reductions in the regeneration of hepatocytes and liver regeneration promoted by ALR. Conclusion: ALR can promote the regeneration of hepatocytes in liver parenchyma, which is achieved by the regulation of autophagy.

[Role of autophagy in acute liver failure induced by D-galactosamine/lipopolysaccharide in mice]

Objective: To investigate the expression and role of autophagy in the progression of acute liver failure (ALF) using the mouse model of ALF induced by D-galactosamine/LPS (D-GalN/LPS). Methods: The C57BL/6 mice were used, and intraperitoneal injection of D-galactosamine (D-GalN) and lipopolysaccharide (LPS) was performed to establish the mouse model of ALF. The mice were divided into control group and 2-, 4-, and 6-hour D-GalN/LPS-induced ALF model groups. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured to assess liver function, and the pathological changes in liver tissue were observed to evaluate the status of liver injury. Quantitative real-time PCR was used to measure the expression of autophagy-related genes, Western blot was used to measure the expression of autophagy-related proteins in liver tissue, and a fluorescence microscope was used to observe the expression of autophagosome in the progression of liver failure. A one-way ANOVA was used for comparison of means of multiple samples between any two groups (LSD-t test for data with homogeneity of variance and Games-Howell method for data with heterogeneity of variance).P< 0.05 was considered statistically significant. Results: The ALF model groups showed gradual liver impairment over the time of D-GalN/LPS stimulation. There were significant increases in ALT and AST after 4 hours; the pathological injury of liver tissue gradually aggravated over the time of D-GalN/LPS stimulation and fulfilled the criteria for ALF at 6 hours. The mRNA and protein expression of autophagy-related genes (ATG-7, ATG-5, Beclin-1, Lamp-1, and LC3a) increased in the early and medium stages of ALF (2 and 4 hours) and decreased after ALF progressed to liver failure (6 hours). As was observed via the fluorescence microscope, the 4-hour D-GalN/LPS-induced ALF model group showed the highest expression of autophagosome. Conclusion: The expression of autophagy gradually increases in the early and medium stages of ALF and decreases when ALF progresses to liver failure. Therefore, autophagy plays an important role in the pathogenesis of ALF.

Bifidobacterium longum BBMN68-specific modulated dendritic cells alleviate allergic responses to bovine β-lactoglobulin in mice

AIMS

This study was designed to demonstrate the protective effects of Bifidobacterium longum BBMN68-specific modulated dendritic cells (DCs) on allergic inflammation in β-lactoglobulin (BLG)-sensitized mice.

METHODS AND RESULTS

BALB/c mice were sensitized to BLG in accordance with a model of food allergy protocol and given oral BBMN68 daily. BBMN68 was found to significantly reduce BLG-specific hypersensitivity reactions by suppressing the aberrant balance of Th1/Th2 responses with increasing the number of CD4+CD25+Foxp3+ Treg cells in mesenteric lymph nodes (MLN) by 48·1%. The level of CD103+DCs was up-regulated by 136·7 and 56·2% in payer's patches and MLN, respectively, in response to the lower expression levels of cell-surface molecules (CD86 and MHC-II) induced by BBMN68 supplementation. The CD11c+DCs isolated from BBMN68 mice showed 45·6% more Foxp3+ expression in vitro.

CONCLUSIONS

These data suggest that BBMN68-specific induction of CD11c+CD103+DCs and semi-mature DCs reduce BLG allergic reactions.

SIGNIFICANCE AND IMPACT OF THE STUDY

These data confirm that BBMN68 may be a suitable therapeutic approach to the alleviation of food allergies, and BBMN68-specific induction of CD11c+CD103+DCs and semi-mature DCs are associated with this protection.

Inhibition of glycogen synthase kinase 3β promotes autophagy to protect mice from acute liver failure mediated by peroxisome proliferator-activated receptor α

Our previous studies have demonstrated that inhibition of glycogen synthase kinase 3β (GSK3β) activity protects mice from acute liver failure (ALF), whereas its protective and regulatory mechanism remains elusive. Autophagy is a recently recognized rudimentary cellular response to inflammation and injury. The aim of the present study was to test the hypothesis that inhibition of GSK3β mediates autophagy to inhibit liver inflammation and protect against ALF. In ALF mice model induced by D-galactosamine (D-GalN) and lipopolysaccharide (LPS), autophagy was repressed compared with normal control, and D-GalN/LPS can directly induce autophagic flux in the progression of ALF mice. Autophagy activation by rapamycin protected against liver injury and its inhibition by 3-methyladenine (3-MA) or autophagy gene 7 (Atg7) small interfering RNA (siRNA) exacerbated liver injury. The protective effect of GSK3β inhibition on ALF mice model depending on the induction of autophagy, because that inhibition of GSK3β promoted autophagy in vitro and in vivo, and inhibition of autophagy reversed liver protection and inflammation of GSK3β inhibition. Furthermore, inhibition of GSK3β increased the expression of peroxisome proliferator-activated receptor α (PPARα), and the downregulated PPARα by siRNA decreased autophagy induced by GSK3β inhibition. More importantly, the expressions of autophagy-related gene and PPARα are significantly downregulated and the activity of GSK3β is significantly upregulated in liver of ALF patients with hepatitis B virus. Thus, we have demonstrated the new pathological mechanism of ALF that the increased GSK3β activity suppresses autophagy to promote the occurrence and development of ALF by inhibiting PPARα pathway.

Motion of Optically Heated Spheres at the Water-Air Interface

A micrometer-sized spherical particle classically equilibrates at the water-air interface in partial wetting configuration, causing about no deformation to the interface. In condition of thermal equilibrium, the particle just undergoes faint Brownian motion, well visible under a microscope. We report experimental observations when the particle is made of a light-absorbing material and is heated up by a vertical laser beam. We show that, at small laser power, the particle is trapped in on-axis configuration, similarly to 2-dimensional trapping of a transparent sphere by optical forces. Conversely, on-axis trapping becomes unstable at higher power. The particle escapes off the laser axis and starts orbiting around the axis. We show that the laser-heated particle behaves as a microswimmer with velocities on the order of several 100 μm/s with just a few milliwatts of laser power.

The dysregulation of endoplasmic reticulum stress response in acute-on-chronic liver failure patients caused by acute exacerbation of chronic hepatitis B

Although endoplasmic reticulum (ER) stress is critical in various liver diseases, its role in acute-on-chronic liver failure (AoCLF) caused by acute exacerbation of chronic hepatitis B (CHB) is still elusive. This study aimed to analyse ER stress responses in the progression of HBV-related AoCLF. Normal liver tissues (n = 10), liver tissues of CHB (n = 12) and HBV-related patients with AoCLF (n = 19) were used. Electron microscopy of the ultrastructure of the ER was carried out on liver specimens. The gene and protein expression levels of ER stress-related genes were measured. We further analysed the correlation between the expression levels of ER stress-related molecules and liver injury. Electron microscopy identified typical features of the ER microstructure in AoCLF subjects. Among the three pathways of unfolded protein responses, the PKR-like ER kinase and inositol-requiring enzyme 1 signalling pathway were activated in CHB subjects and inactivated in AoCLF subjects, while the activating transcription factor 6 signalling pathway was sustained in the activated form during the progression of AoCLF; the expression of glucose-regulated protein (Grp)78 and Grp94 was gradually decreased in AoCLF subjects compared to healthy individuals and CHB subjects, showing a negative correlation with serum ALT, AST and TBIL; moreover, the ER stress-related apoptosis molecules were activated in the progression of acute exacerbation of CHB. The dysregulated ER stress response may play a complicated role in the pathogenesis of AoCLF, and a severe ER stress response may predict the occurrence of AoCLF caused by acute exacerbation of CHB.

Swimming exercise ameliorates neurocognitive impairment induced by neonatal exposure to isoflurane and enhances hippocampal histone acetylation in mice

Isoflurane-induced neurocognitive impairment in the developing rodent brain is well documented, and regular physical exercise has been demonstrated to be a viable intervention for some types of neurocognitive impairment. This study was designed to investigate the potential protective effect of swimming exercise on both neurocognitive impairment caused by repeated neonatal exposure to isoflurane and the underlying molecular mechanism. Mice received 0.75% isoflurane exposures for 4h on postnatal days 7, 8, and 9. From the third month after anesthesia, the mice were subjected to regular swimming exercise for 4weeks, followed by a contextual fear condition (CFC) trial. We found that repeated neonatal exposure to isoflurane reduced freezing behavior during CFC testing and deregulated hippocampal histone H4K12 acetylation. Conversely, mice subjected to regular swimming exercise showed enhanced hippocampal H3K9, H4K5, and H4K12 acetylation levels, increased numbers of c-Fos-positive cells 1h after CFC training, and less isoflurane-induced memory impairment. We also observed increases in histone acetylation and of cAMP-response element-binding protein (CREB)-binding protein (CBP) during the swimming exercise program. The results suggest that neonatal isoflurane exposure-induced memory impairment was associated with dysregulation of H4K12 acetylation, which may lead to less hippocampal activation following learning tasks. Swimming exercise was associated with enhanced hippocampal histone acetylation and CBP expression. Exercise most likely ameliorated isoflurane-induced memory impairment by enhancing hippocampal histone acetylation and activating more neuron cells during memory formation.

Plasma soluble Tim-3 emerges as an inhibitor in sepsis: sepsis contrary to membrane Tim-3 on monocytes

Immune dysfunction is the main characteristic of sepsis. T cell Ig and mucin domain protein 3 (Tim-3) on the monocytes has been reported to promote immune homeostasis during sepsis, but the influences of plasm soluble Tim-3 (sTim-3) on the immune system during sepsis remain unknown. Here, 100 patients with different severities of sepsis (40 sepsis, 42 severe sepsis, and 18 septic shock) were enrolled in this study. The Tim-3 and human leukocyte antigen-DR (HLA-DR) on the circulating monocytes were detected using flow cytometry. Plasma sTim-3 was detected by enzyme-linked immunosorbent assay. Inflammatory factors and two kinds of A disintegrin and metalloprotease (ADAM) - ADAM10 and ADAM17 were assessed. The Tim-3 and HLA-DR on the monocytes decreased with increasing sepsis severity. The sTim-3 was reduced in the sepsis and severe sepsis patients but was elevated in the septic shock patients who exhibited significant immunosuppression as predicted by HLA-DR. sTim-3 levels were negatively correlated with IL-12 and TNF-α. ADAM10 and ADAM17, sheddases of Tim-3, exhibited trends toward elevations in the septic shock group. In conclusion, sTim-3 was involved in the development of sepsis. The homeostasis-promoting role of the Tim-3 on the monocytes was disrupted, while the inhibitory role of sTim-3 emerged during sepsis-induced immunosuppression.

Correlation between down-expression of miR-431 and clinicopathological significance in HCC tissues

BACKGROUND AND AIMS

Researches have shown that miRNAs have been proposed as novel diagnostic biomarkers for classification and prognostic stratification of HCC. However, whether or not miR-431 contributes to the progression of HCC remains unknown. Therefore, we aimed to investigate the clinicopathological significance of miR-431 in HCC.

METHODS

MiR-431 expression in 95 HCC cases and corresponding adjacent non-cancerous tissues was evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Furthermore, statistical analysis was performed to identify the correlations between expression of miR-431 and a variety of clinicopathological parameters and patient recurrence. The area under the receiver operating characteristic curve (AUC) was used to evaluate the accuracy of miR-431 as a biomarker for HCC diagnosis and prediction of disease deterioration.

RESULTS

MiR-431 was markedly down-regulated in the HCC samples (1.1885 ± 0.75867) compared with corresponding adjacent tumor tissues (1.7957 ± 0.89333, P < 0.001). The AUC of low miR-431 expression to diagnose HCC was 0.668 (95 % CI 0.592-0.744, P < 0.001). MiR-431 down-expression was correlated with multiple malignant characteristics, including lymph node metastasis (r = -0.455, P < 0.001), clinical TNM stage (r = -0.223, P = 0.030), MTDH (r = -0.292, P = 0.006), vaso-invasion (r = -0.204, P = 0.047), MVD (r = -0.281, P = 0.006) and HCV (r = 0.215, P = 0.037). Additionally, the recurrent time of lower miR-431 expression group was 56.602 ± 3.914 months, much longer than that in the high expression group (50.009 ± 2.731 months), however, no significant difference was noted (χ (2) = 0.005, P = 0.943).

CONCLUSIONS

The down-expression of miR-431 is partially responsible for a series of clinicopathological features which may be tightly correlated with the progression of HCC. Thus, expression of miR-431 may be proposed as a new factor in association with the progression of HCC.