Rapid and efficient separation and identification of the two molecular forms of human adenosine deaminase by thin-layer gel filtration chromatography

Two molecular forms of adenosine deaminase have been found in human tissues. The column gel filtration method has been used for the separation of the two enzyme forms. Routine separation and analysis of the enzyme forms based on the molecular size difference can be achieved by thin-layer gel filtration on Sephadex G-200 superfine gel. The thin-layer method has been found to be more rapid and efficient than the column method. Enzymes in crude preparations can be studied effectively with the thin-layer method.     

Osmotic stress induces gut microbiota community shift in fish

Alteration of the gut microbiota plays an important role in animal health and metabolic diseases. However, little is known with respect to the influence of environmental osmolality on the gut microbial community. The aim of the current study was to determine whether the reduction in salinity affects the gut microbiota and identify its potential role in salinity acclimation. Using Oryzias melastigma as a model organism to perform progressive hypotonic transfer experiments, we evaluated three conditions: seawater control (SW), SW to 50% sea water transfer (SFW) and SW to SFW to freshwater transfer (FW). Our results showed that the SFW and FW transfer groups contained higher operational taxonomic unit microbiota diversities. The dominant bacteria in all conditions constituted the phylum Proteobacteria, with the majority in the SW and SFW transfer gut comprising Vibrio at the genus level, whereas this population was replaced by Pseudomonas in the FW transfer gut. Furthermore, our data revealed that the FW transfer gut microbiota exhibited a reduced renin–angiotensin system, which is important in SW acclimation. In addition, induced detoxification and immune mechanisms were found in the FW transfer gut microbiota. The shift of the bacteria community in different osmolality environments indicated possible roles of bacteria in facilitating host acclimation.     

Regulation of ICAM‐1 expression in gingival fibroblasts infected with high‐glucose‐treated P. gingivalis

Porphyromonas gingivalis is a major pathogen in the initiation and progression of periodontal disease, which is recognized as a common complication of diabetes. ICAM‐1 expression by human gingival fibroblasts (HGFs) is crucial for regulating local inflammatory responses in inflamed periodontal tissues. However, the effect of P. gingivalis in a high‐glucose situation in regulating HGF function is not understood. The P. gingivalis strain CCUG25226 was used to study the mechanisms underlying the modulation of HGF ICAM‐1 expression by invasion of high‐glucose‐treated P. gingivalis (HGPg). A high‐glucose condition upregulated fimA mRNA expression in P. gingivalis and increased its invasion ability in HGFs. HGF invasion with HGPg induced increases in the expression of ICAM‐1. By using specific inhibitors and short hairpin RNA (shRNA), we have demonstrated that the activation of p38 MAPK and Akt pathways is critical for HGPg‐induced ICAM‐1 expression. Luciferase reporters and chromatin immunoprecipitation assays suggest that HGPg invasion increases NF‐κB‐ and Sp1‐DNA‐binding activities in HGFs. Inhibition of NF‐κB and Sp1 activations blocked the HGPg‐induced ICAM‐1 promoter activity and expression. The effect of HGPg on HGF signalling and ICAM‐1 expression is mediated by CXC chemokine receptor 4 (CXCR4). Our findings identify the molecular pathways underlying HGPg‐dependent ICAM‐1 expression in HGFs, providing insight into the effect of P. gingivalis invasion in HGFs.     

Inhibition of Megakaryocyte Development in the Bone Marrow Underlies Dengue Virus-Induced Thrombocytopenia in Humanized Mice

A characteristic clinical feature of dengue virus infection is thrombocytopenia, though its underlying mechanism is not definitively determined. By adoptive transfer of human CD34⁺ fetal liver cells into immunodeficient mice, we have constructed humanized mice with significant levels of human platelets, monocytes/macrophages, and hepatocytes. Infection of these mice with both lab-adapted and clinical strains of dengue virus induces characteristic human hematological changes, including transient leukopenia and thrombocytopenia. We show that the specific depletion of human platelets is not mediated by antibodies in the periphery or reduced production of human thrombopoietin in the liver but reduction of human megakaryocytes and megakaryocyte progenitors in the bone marrow of the infected mice. These findings identify inhibition of platelet production in the bone marrow as a key mechanism underlying dengue-induced thrombocytopenia and suggest the utility of the improved humanized mouse model in studying dengue virus infection and pathogenesis in a human cell context.     

Apoptosis through Bcl-2/Bax and Cleaved Caspase Up-Regulation in Melanoma Treated by Boron Neutron Capture Therapy

Boron neutron capture therapy (BNCT) is a binary treatment involving selective accumulation of boron carriers in a tumor followed by irradiation with a thermal or epithermal neutron beam. The neutron capture reaction with a boron-10 nucleus yields high linear energy transfer (LET) particles, alpha and ⁷Li, with a range of 5 to 9 µm. These particles can only travel very short distances and release their damaging energy directly into the cells containing the boron compound. We aimed to evaluate proliferation, apoptosis and extracellular matrix (ECM) modifications of B16F10 melanoma and normal human melanocytes after BNCT. The amounts of soluble collagen and Hsp47, indicating collagen synthesis in the ECM, as well as the cellular markers of apoptosis, were investigated. BNCT decreased proliferation, altered the ECM by decreasing collagen synthesis and induced apoptosis by regulating Bcl-2/Bax in melanoma. Additionally, BNCT also increased the levels of TNF receptor and the cleaved caspases 3, 7, 8 and 9 in melanoma. These results suggest that multiple pathways related to cell death and cell cycle arrest are involved in the treatment of melanoma by BNCT.     

Fill Factor Losses in Cu2ZnSn(SxSe1−x)4 Solar Cells: Insights from Physical and Electrical Characterization of Devices and Exfoliated Films

Besides the open circuit voltage (V_OC) deficit, fill factor (FF) is the second most significant parameter deficit for earth‐abundant kesterite solar cell technology. Here, various pathways for FF loss are discussed, with focus on the series resistance issue and its various contributing factors. Electrical and physical characterizations of the full range of bandgap (E_g = 1.0–1.5 eV) Cu₂ZnSn(S_xSe_1?x)₄ (CZTSSe) devices, as well as bare and exfoliated films with various S/(S + Se) ratios, are performed. High intensity Suns‐V_OC measurement indicates a nonohmic junction developing in high bandgap CZTSSe. Grazing incidence X‐ray diffraction, Raman mapping, field emission scanning electron microscopy, and X‐ray photoelectron spectroscopy indicate the formation of Sn(S,Se)₂, Mo(S,Se)₂, and Zn(S,Se) at the high bandgap CZTSSe/Mo interface, contributing to the increased series resistance (R_S) and nonohmic back contact characteristics. This study offers some clues as to why the record‐CZTSSe solar cells occur within a bandgap range centered around 1.15 eV and offers some direction for further optimization.     

Augmentation of Autoantibodies by Helicobacter pylori in Parkinson’s Disease Patients May Be Linked to Greater Severity

Parkinson''s disease (PD) is the second most common chronic and progressive neurodegenerative disorder. Its etiology remains elusive and at present only symptomatic treatments exists. Helicobacter pylori chronically colonizes the gastric mucosa of more than half of the global human population. Interestingly, H. pylori positivity has been found to be associated with greater of PD motor severity. In order to investigate the underlying cause of this association, the Sengenics Immunome protein array, which enables simultaneous screening for autoantibodies against 1636 human proteins, was used to screen the serum of 30 H. pylori-seropositive PD patients (case) and 30 age- and gender-matched H. pylori-seronegative PD patients (control) in this study. In total, 13 significant autoantibodies were identified and ranked, with 8 up-regulated and 5 down-regulated in the case group. Among autoantibodies found to be elevated in H. pylori-seropositive PD were included antibodies that recognize Nuclear factor I subtype A (NFIA), Platelet-derived growth factor B (PDGFB) and Eukaryotic translation initiation factor 4A3 (eIFA3). The presence of elevated autoantibodies against proteins essential for normal neurological functions suggest that immunomodulatory properties of H. pylori may explain the association between H. pylori positivity and greater PD motor severity.     

CpG/CpNpG motifs in the coding region are preferred sites for mutagenesis in the breast cancer susceptibility genes

The range of BRCA1/BRCA2 gene mutations is diverse and the mechanism accounting for this heterogeneity is obscure. To gain insight into the endogenous mutational mechanisms involved, we evaluated the association of specific sequences (i.e. CpG/CpNpG motifs, homonucleotides, short repeats) and mutations within the genes. We classified 1337 published mutations in BRCA1 (1765 BRCA2 mutations) for each specific sequence, and employed computer simulation combined with mathematical calculations to estimate the true underlying tendency of mutation occurrence. Interestingly, we found no mutational bias to homonucleotides and repeats in deletions/insertions and substitutions but striking bias to CpG/CpNpG in substitutions in both genes. This suggests that methylation-dependent DNA alterations would be a major mechanism for mutagenesis.