Genome-wide histone methylation profile for heart failure

Epigenetic alterations are implicated in the development of cardiac hypertrophy and heart failure, but little is known of which epigenetic changes in which regions of the genome play such a role. We now show that trimethylation of histone H3 on lysine-4 (K4TM) or lysine-9 (K9TM) is markedly affected in cardiomyocytes in association with the development of heart failure in a rat disease model. High-throughput pyrosequencing performed with ChIP products for K4TM or K9TM prepared from human left ventricular tissue with retained or damaged function also revealed that protein-coding genes located in the vicinity of K4TM marks differ between functional and disabled myocytes, yet both sets of genes encode proteins that function in the same signal transduction pathways for cardiac function, indicative of differential K4TM marking during the development of heart failure. However, K9TM mark-profile was less dependent on the disease status compared to that of K4TM. Our data collectively reveal global epigenetic changes in cardiac myocytes associated with heart failure.     

In vivo induction of apoptosis in the thymus by administration of mycobacterial cord factor (trehalose 6,6'-dimycolate).

It is reported that some bacteria or bacterial components cause thymic atrophy via the apoptotic process. The present study demonstrated for the first time in vivo induction of apoptosis in the mouse thymus by mycobacterial cord factor (CF) (trehalose 6,6'-dimycolate). When 300 microg of purified CF from Mycobacterium tuberculosis was intravenously administered to BALB/c mice in the form of water-in-oil-in-water (w/o/w) emulsion, thymic atrophy and pulmonary granulomas were induced with a peak on day 7, whereas, in the form of liposomes, CF induced thymic atrophy on days 14 to 21 in parallel with the development of hepatic granulomas. Thymic atrophy resulted from the depletion of cortical lymphocytes via apoptosis as revealed by DNA fragmentation and karyorrhectic changes. In contrast, mycobacterial sulfatide (2,3,6,6'-tetraacyl trehalose 2'-sulfate) caused neither thymic atrophy nor granuloma formation. Compared to lipopolysaccharide-induced thymocyte apoptosis, CF (w/o/w)-induced thymocyte apoptosis developed more slowly, reached a maximum later, and lasted longer but was less intense. Although serum tumor necrosis factor alpha (TNF-alpha) levels in CF-treated mice were not significantly elevated, administration of anti-TNF-alpha antibody almost completely inhibited thymic atrophy and granuloma formation. Serum corticosterone levels were only slightly elevated by CF administration. The present results indicate that mycobacterial CF induces thymic atrophy via apoptosis, which is closely linked with granuloma formation.     

Glyceraldehyde 3-phosphate dehydrogenase is a novel autoantigen leading autoimmune responses to proliferating cell nuclear antigen multiprotein complexes in lupus patients

Using 2-dimensional electrophoresis and ion-pair chromatography, we have identified elements of proliferating cell nuclear antigen (PCNA) multiprotein complexes that are reactive to antibodies in sera from patients with systemic lupus erythematosus. Among the various elements of the complexes, a 37 kDa protein (PI 8.5) that specifically reacted with SLE sera, but not with sera from patients with other connective tissue diseases, was identified as glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Immunoblot analysis showed that SLE sera reactive with the 37 kDa protein specifically reacted with GAPDH, as did anti-GAPDH mAbs. The purified autoantibodies to GAPDH from lupus serum showed both nuclear speckled and cytoplasmic staining patterns in immunofluorescence on Hep-2 cells. In addition, enzyme-linked immunosorbent assay (ELISA) revealed the presence of anti-GAPDH autoantibodies in 47% of lupus patients. Longitudinal analysis of the reactivity of lupus sera to PCNA complexes showed the autoimmune response to spread from GAPDH to other elements of PCNA complexes, and the presence of anti-GAPDH antibodies was significantly correlated with increased levels of serum PCNA. Taken together, these findings suggest that GAPDH interacting with PCNA in association with its cellular function is a novel autoantigen recognized by lupus sera, and that GAPDH thus plays an important role in the induction of autoimmune responses against the PCNA complex.     

Schwannoma arising from the sublingual gland

Sublingual gland tumors, especially mesenchymal tumors, are extremely rare. We describe the first reported case of schwannoma arising from the sublingual gland with details of the histopathologic and immunohistochemical features. A 70-year-old woman developed a painless swelling on the floor of the mouth. The excised material was sublingual gland tissue with an ovoid, grayish-yellow solid tumorous mass at the cut surface. The tumor was composed of proliferated spindle-shaped tumor cells exhibiting palisading patterns. In the center of the tumor, a small salivary gland component was recognized. Immunohistochemically, the tumor cells were strongly positive for S-100 protein but negative for neurofilament protein. The Ki-67 labeling index was 4.58. The clear presence of a remnant sublingual gland lobule in the present tumor provided convincing evidence that it was a schwannoma arising from the sublingual gland and thus the first of its type to be reported.     

Teleost IL-6 promotes antibody production through STAT3 signaling via IL-6R and gp130

Teleost IL-6 is upregulated after antigen stimulation; therefore, we hypothesized that fish IL-6 contributes to antibody production during immune responses against infections. To verify this hypothesis, we first cloned IL-6R and gp130 in fugu (Takifugu rubripes) in the present study. The membrane and soluble forms of IL-6R were identified by the identification of cDNA clones of IL-6R homologues. Three STAT3-docking sites were found in the intracellular region of fugu gp130. Expression analysis showed that fugu IL-6R and gp130 were expressed in mIgM(+) B cells, suggesting that fugu B cells are stimulated by IL-6. Recombinant fugu IL-6 (rfIL-6) increased the gene expression of secretory antibodies by mIgM(+) B cells in vitro. The rfIL-6 and soluble form of rfIL-6R activated STAT3 phosphorylation in the B cells and a cultured cell line transfected with fugu gp130. These results indicate that fugu IL-6 enhances antibody production in the B-cell lineage via gp130 and STAT3 signaling.     

Development of liposomes and pseudovirions with fusion activity for efficient gene delivery

For efficient gene delivery, chimeric vectors combining non-viral vectors with viral components have been developed. In particular, increasing attention has been paid to viral fusion activity. HVJ (hemagglutinating virus of Japan; Sendai virus) fuses with the cell membrane at neutral pH, and HN and F, fusion proteins of the virus, contribute to the cell fusion. For fusion-mediated gene transfer, DNA-loaded liposomes were fused with UV-inactivated HVJ to form the fusion liposome, HVJ-liposome. Fusion-mediated delivery protects the molecules incorporated in the liposome from degradation in endosomes and lysosomes before reaching the cytoplasm. Reconstituted pseudovirions of fusion-competent viruses such as HVJ and influenza virus have been also developed by a detergent-lysis and-removal method. A more direct and practical approach is the conversion of fusion-competent virions to non-viral gene delivery particles. Based on this concept, the HVJ envelope vector was developed using inactivated particles of HVJ and has been utilized for gene therapy experiments and functional screening for therapeutic genes. A tissue-targeting HVJ envelope vector was also constructed.     

Epstein–Barr virus infection induces genome‐wide de novo DNA methylation in non‐neoplastic gastric epithelial cells

Epstein–Barr virus (EBV)‐positive gastric cancer (GC) shows a higher DNA methylation epigenotype. EBV infection can causally induce genome‐wide aberrant DNA methylation, as previously demonstrated by in vitro infection experiments in the low‐methylation GC cell line MKN7. However, whether EBV exerts DNA methylation remodelling properties in non‐neoplastic epithelial cells remains unclear. Here we performed post‐infection time‐series DNA methylation analyses using the immortalized normal gastric epithelial cell line GES1. Genome‐wide analysis using Illumina's Infinium 450 k BeadArray demonstrated global de novo DNA methylation from post‐infection day 17, which was completed by 28 days in a manner similar to that observed in MKN7 cells. De novo methylation of all types of GC‐specific methylation marker genes was observed, indicating that EBV infection is sufficient for gastric epithelial cells to acquire an EBV‐positive GC epigenotype. Pyrosequencing demonstrated that methylation of the viral genome preceded that of the host cellular genome, suggesting the existence of well‐ordered mechanisms that induce methylation. Spatiotemporal representation with differential models revealed dynamic alterations of DNA methylation in promoter regions, occurring from lower‐CpG peripheral regions and extending to higher‐CpG core regions. In summary, EBV infection exerted powerful pressure to induce global de novo DNA methylation in non‐neoplastic cells within a month in a spatiotemporally well‐ordered manner. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.