Changes in glycosphingolipid composition during differentiation of human embryonic stem cells to ectodermal or endodermal lineages.

Glycosphingolipids (GSLs) are ubiquitous components of cell membranes that can act as mediators of cell adhesion and signal transduction and can possibly be used as cell type-specific markers. Our previous study indicated that there was a striking switch in the core structures of GSLs during differentiation of human embryonic stem cells (hESCs) into embryoid body (EB), suggesting a close association of GSLs with cell differentiation. In this study, to further clarify if alterations in GSL patterns are correlated with lineage-specific differentiation of hESCs, we analyzed changes in GSLs as hESCs were differentiated into neural progenitors or endodermal cells by matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) and tandem mass spectrometry (MS/MS) analyses. During hESC differentiation into neural progenitor cells, we found that the core structures of GSLs switched from globo- and lacto- to mostly ganglio-series dominated by GD3. On the other hand, when hESCs were differentiated into endodermal cells, patterns of GSLs totally differed from those observed in EB outgrowth and neural progenitors. The most prominent GSL identified by the MALDI-MS and MS/MS analysis was Gb(4) Ceramide, with no appreciable amount of stage-specific embryonic antigens 3 or 4, or GD3, in endodermal cells. These changes in GSL profiling were accompanied by alterations in the biosynthetic pathways of expressions of key glycosyltransferases. Our findings suggest that changes in GSLs are closely associated with lineage specificity and differentiation of hESCs.

Liver fibrosis regression correlates with downregulation in liver angiogenesis in chronic hepatitis C through viral eradication.

OBJECTIVES: The impact of viral eradication on hepatic angiogenesis is unknown. This study aimed to analyze the correlations of liver angiogenesis with liver fibrosis progression or regression in chronic hepatitis C (CHC) after viral eradication. METHODS: From 2003 to 2020, a cohort of 130 eligible participants underwent paired percutaneous liver biopsies (median = 48 months apart; range = 46-62) at the treatment baseline and after sustained virological response to CHC treatment at the tertiary referral center. The collagen proportionate area (CPA) of liver tissue sections was determined using picrosirius red staining through digital image analysis. CD34 and α-smooth muscle actin (α-SMA) phenotypically quantitated liver angiogenesis and myofibroblasts, respectively, through immunohistochemistry staining, to correlate the total, portal, and extraportal liver angiogenesis with fibrogenesis. RESULTS: Paired histology manifested significant regressions in fibrosis stages, and necroinflammatory grades (both P < 0.001). The median of changes in CPAs (follow-up minus baseline) was -6.12% (interquartile range = -12.35 to -2.05%). The median of CPA changes per year was -1.38%/year (interquartile range = -2.98 to -0.51%/year). The significance of declines in total CD34 [coefficient (95% confidence interval), 5.577 (3.286-7.868); P < 0.001] outweighed α-SMA declines, when explaining (R2 = 0.522; adjusted R2 = 0.502) the CPA declines through multiple regression analysis adjusting for other histological variables. CONCLUSION: Through viral eradication in CHC, the downregulated liver angiogenesis significantly explains the CPA regression.

Serum miR-21 correlates with the histological stage of chronic hepatitis B-associated liver fibrosis.

This study aimed to investigate the correlation between serum microRNA levels and histological stages of liver fibrosis in patients with chronic hepatitis B (CHB). A total of 28 patients with CHB who received liver biopsy at China Medical University Hospital between October 2012 and April 2013 were included in the study. The patients were divided into four groups according to the histological stages of liver fibrosis by using the METAVIR score. Serum microRNA levels were tested using quantitative real-time PCR after microRNA extraction from patients' serum. Of all the tested microRNAs, miR-21, miR-29, and miR-221 were expressed in the serum. The expression levels of serum miR-21 were significantly correlated with liver fibrosis stages (r = 0.420, P = 0.026). The expression levels of serum miR-21 were significantly correlated with cirrhosis (METAVIR F4 vs. F1-F3, r = 0.386, P = 0.043). The grades of serum miR-21 showed significant ordered differences among different stages of liver fibrosis (P = 0.019). However, miR-21 exhibited an inferior predictive performance for liver fibrosis F2-F4 (AUROC = 0.69) compared with other noninvasive markers of liver fibrosis, namely the aspartate aminotransferase (AST) to platelet ratio index (APRI) and Fibrosis-4 (FIB-4) score (AUROC = 0.83 and 0.86, respectively). Serum miR-21 correlated with the histological stage of liver fibrosis in patients with CHB. The predictive performance of serum miR-21 for the histological stage of liver fibrosis tended to be inferior to those of the APRI and FIB-4 score.

The Effect of a Virtual Reality Game Intervention on Balance for Patients with Stroke: A Randomized Controlled Trial.

OBJECTIVE: The aim of this study was to investigate the effects of virtual reality (VR) balance training conducted using Kinect for Xbox® games on patients with chronic stroke. MATERIALS AND METHODS: Fifty patients with mild to moderate motor deficits were recruited and randomly assigned to two groups: VR plus standard treatment group and standard treatment (ST) group. In total, 12 training sessions (90 minutes a session, twice a week) were conducted in both groups, and performance was assessed at three time points (pretest, post-test, and follow-up) by a blinded assessor. The outcome measures were the Berg Balance Scale (BBS), Functional Reach Test, and Timed Up and Go Test (cognitive; TUG-cog) for balance evaluations; Modified Barthel Index for activities of daily living ability; Activities-specific Balance Confidence Scale for balance confidence; and Stroke Impact Scale for quality of life. The pleasure scale and adverse events were also recorded after each training session. RESULTS: Both groups exhibited significant improvement over time in the BBS (P = 0.000) and TUG-cog test (P = 0.005). The VR group rated the experience as more pleasurable than the ST group during the intervention (P = 0.027). However, no significant difference was observed in other outcome measures within or between the groups. No serious adverse events were observed during the treatment in either group. CONCLUSIONS: VR balance training by using Kinect for Xbox games plus the traditional method had positive effects on the balance ability of patients with chronic stroke. The VR group experienced higher pleasure than the ST group during the intervention.

Earth's magnetosphere and outer radiation belt under sub-Alfvénic solar wind.

The interaction between Earth's magnetic field and the solar wind results in the formation of a collisionless bow shock 60,000-100,000 km upstream of our planet, as long as the solar wind fast magnetosonic Mach (hereafter Mach) number exceeds unity. Here, we present one of those extremely rare instances, when the solar wind Mach number reached steady values <1 for several hours on 17 January 2013. Simultaneous measurements by more than ten spacecraft in the near-Earth environment reveal the evanescence of the bow shock, the sunward motion of the magnetopause and the extremely rapid and intense loss of electrons in the outer radiation belt. This study allows us to directly observe the state of the inner magnetosphere, including the radiation belts during a type of solar wind-magnetosphere coupling which is unusual for planets in our solar system but may be common for close-in extrasolar planets.

Antioxidant activity of Glossogyne tenuifolia.

Glossogyne tenuifolia is a native traditional anti-inflammatory herb in Taiwan. It has previously been shown that the ethanol extract of G. tenuifolia (GT) inhibited the LPS-induced inflammatory mediator release from murine macrophage cell line and human whole blood. In the present work, the ethanol extracts of G. tenuifolia and its major constituent, luteolin-7-glucoside, were shown to be scavengers of 1,1-diphenyl-2-picrylhydrazyl, superoxide, and hydroxyl radicals. Moreover, copper-induced low-density lipoprotein oxidation was suppressed by GT and luteolin-7-glucoside as measured by decreased formation of malondialdehyde and conjugated diene as well as reduced electrophoretic mobility. GT and luteolin-7-glucoside were also against N-formyl-methionyl-leucyl-phenylalanine-induced reactive oxygen species (ROS) production in human polymorphonuclear neutrophils and peripheral blood mononuclear cells. In summary, these data indicated that GT is a potential ROS scavenger and may prevent atherosclerosis via inhibiting LDL oxidation or ROS production in human leukocytes. Moreover, luteolin-7-glucoside may serve as the active principal of GT.

Ser/Thr kinase-like protein of Nicotiana benthamiana is involved in the cell-to-cell movement of Bamboo mosaic virus.

To investigate the plant genes affected by Bamboo mosaic virus (BaMV) infection, we applied a cDNA-amplified fragment length polymorphism technique to screen genes with differential expression. A serine/threonine kinase-like (NbSTKL) gene of Nicotiana benthamiana is upregulated after BaMV infection. NbSTKL contains the homologous domain of Ser/Thr kinase. Knocking down the expression of NbSTKL by virus-induced gene silencing reduced the accumulation of BaMV in the inoculated leaves but not in the protoplasts. The spread of GFP-expressing BaMV in the inoculated leaves is also impeded by a reduced expression of NbSTKL. These data imply that NbSTKL facilitates the cell-to-cell movement of BaMV. The subcellular localization of NbSTKL is mainly on the cell membrane, which has been confirmed by mutagenesis and fractionation experiments. Combined with the results showing that active site mutation of NbSTKL does not change its subcellular localization but significantly affects BaMV accumulation, we conclude that NbSTKL may regulate BaMV movement on the cell membrane by its kinase-like activity. Moreover, the transient expression of NbSTKL does not significantly affect the accumulation of Cucumber mosaic virus (CMV) and Potato virus X (PVX); thus, NbSTKL might be a specific protein facilitating BaMV movement.

Caspase activation of mammalian sterile 20-like kinase 3 (Mst3). Nuclear translocation and induction of apoptosis.

Mammalian Sterile 20-like kinase 3 (Mst3), the physiological functions of which are unknown, is a member of the germinal center kinase-III family. It contains a conserved kinase domain at its NH(2) terminus, whereas there is a regulatory domain at its COOH terminus. In this study we demonstrate that endogenous Mst3 is specifically cleaved when Jurkat cells were treated with anti-Fas antibody or staurosporine and that this cleavage is inhibited by the caspase inhibitor, Ac-DEVD-CHO. Using apoptotic Jurkat cell extracts and recombinant caspases, we mapped the caspase cleavage site, AETD(313), which is at the junction of the NH(2)-terminal kinase domain and the COOH-terminal regulatory domain. Caspase-mediated cleavage of Mst3 activates its intrinsic kinase activity, suggesting that the COOH-terminal domain of Mst3 negatively regulates the kinase domain. Furthermore, proteolytic removal of the Mst3 COOH-terminal domain by caspases promotes nuclear translocation. Ectopic expression of either wild-type or COOH-terminal truncated Mst3 in cells results in DNA fragmentation and morphological changes characteristic of apoptosis. By contrast, no such changes were exhibited for catalytically inactive Mst3, implicating the involvement of Mst3 kinase activity for mediation of these effects. Collectively, these results support the notion that caspase-mediated proteolytic activation of Mst3 contributes to apoptosis.