Association between sleep disorder and atrial fibrillation: A nationwide population-based cohort study.

OBJECTIVES: Sleep disorder (SD), especially sleep apnea, and its effect on atrial fibrillation (AF) are gathering attention. However, other SDs may also play an essential role in AF. The aim of the study is to investigate the effects of other SDs on the risk of atrial fibrillation development. METHODS: This study investigated the risk of AF in people diagnosed with SD compared with that in age and sex-matched unaffected individuals. This longitudinal, nationwide, population-based cohort study was conducted using data from the Taiwan National Health Insurance Research Database (NHIRD) of individuals diagnosed with SD from January 1, 2001, to December 31, 2012. RESULTS: The sample consisted of 193,288 people with the SD, which include of 4406 people with sleep apnea, 73,704 people with insomnia, 107,395 people with sleep disturbance, 7,783 people with other SD, and 193,288 matched controls. A Cox proportional hazard regression was used to compute the risk of AF in people with SD and subgroup of SD, relative to that in people without SD. The AF incidences were 1.21-fold higher (95% CI 1.15-1.27) in the SD cohort, 1.19-fold higher (95% CI 0.91-1.56) in the sleep apnea cohort, 1.26-fold higher (95% CI 1.19-1.34) in the insomnia cohort, 1.15-fold higher (95% CI 1.08-1.22) in the sleep disturbance cohort, and 1.30-fold higher (95% CI 1.11-1.53) in other SDs, than in the control cohort, after age, sex, and comorbidities were adjusted. CONCLUSIONS: This nationwide population-based cohort study indicates a strong relationship between SD and incident AF, and insomnia has a higher impact on AF compared with other SD.

Intracellular Transport of Vaccinia Virus in HeLa Cells Requires WASH-VPEF/FAM21-Retromer Complexes and Recycling Molecules Rab11 and Rab22.

UNLABELLED: Vaccinia virus, the prototype of the Orthopoxvirus genus in the family Poxviridae, infects a wide range of cell lines and animals. Vaccinia mature virus particles of the WR strain reportedly enter HeLa cells through fluid-phase endocytosis. However, the intracellular trafficking process of the vaccinia mature virus between cellular uptake and membrane fusion remains unknown. We used live imaging of single virus particles with a combination of various cellular vesicle markers, to track fluorescent vaccinia mature virus particle movement in cells. Furthermore, we performed functional interference assays to perturb distinct vesicle trafficking processes in order to delineate the specific route undertaken by vaccinia mature virus prior to membrane fusion and virus core uncoating in cells. Our results showed that vaccinia virus traffics to early endosomes, where recycling endosome markers Rab11 and Rab22 are recruited to participate in subsequent virus trafficking prior to virus core uncoating in the cytoplasm. Furthermore, we identified WASH-VPEF/FAM21-retromer complexes that mediate endosome fission and sorting of virus-containing vesicles prior to virus core uncoating in the cytoplasm. IMPORTANCE: Vaccinia mature virions of the WR strain enter HeLa cells through fluid phase endocytosis. We previously demonstrated that virus-containing vesicles are internalized into phosphatidylinositol 3-phosphate positive macropinosomes, which are then fused with Rab5-positive early endosomes. However, the subsequent process of sorting the virion-containing vesicles prior to membrane fusion remains unclear. We dissected the intracellular trafficking pathway of vaccinia mature virions in cells up to virus core uncoating in cytoplasm. We show that vaccinia mature virions first travel to early endosomes. Subsequent trafficking events require the important endosome-tethered protein VPEF/FAM21, which recruits WASH and retromer protein complexes to the endosome. There, the complex executes endosomal membrane fission and cargo sorting to the Rab11-positive and Rab22-positive recycling pathway, resulting in membrane fusion and virus core uncoating in the cytoplasm.

Structures of Helicobacter pylori shikimate kinase reveal a selective inhibitor-induced-fit mechanism.

Shikimate kinase (SK), which catalyzes the specific phosphorylation of the 3-hydroxyl group of shikimic acid in the presence of ATP, is the enzyme in the fifth step of the shikimate pathway for biosynthesis of aromatic amino acids. This pathway is present in bacteria, fungi, and plants but absent in mammals and therefore represents an attractive target pathway for the development of new antimicrobial agents, herbicides, and antiparasitic agents. Here we investigated the detailed structure-activity relationship of SK from Helicobacter pylori (HpSK). Site-directed mutagenesis and isothermal titration calorimetry studies revealed critical conserved residues (D33, F48, R57, R116, and R132) that interact with shikimate and are therefore involved in catalysis. Crystal structures of HpSK·SO(4), R57A, and HpSK•shikimate-3-phosphate • ADP show a characteristic three-layer architecture and a conformationally elastic region consisting of F48, R57, R116, and R132, occupied by shikimate. The structure of the inhibitor complex, E114A • 162535, was also determined, which revealed a dramatic shift in the elastic LID region and resulted in conformational locking into a distinctive form. These results reveal considerable insight into the active-site chemistry of SKs and a selective inhibitor-induced-fit mechanism.

NBM-HD-3, a novel histone deacetylase inhibitor with anticancer activity through modulation of PTEN and AKT in brain cancer cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Taiwanese green propolis (TGP) extract contains a variety of chemical components and has proven to have broad-spectrum biological activities, including anticancer, antioxidant, and antimicrobial activities. Propolin G, an active anticancer component of TGP, was isolated and characterized in this study. Histone deacetylase inhibitors (HDACis) have been shown to be effective anticancer agents. The aim of this study was to develop a novel HDACi and investigate its anticancer mechanism. MATERIALS AND METHODS: NBM-HD-3, a novel HDACi, was derived from propolin G. Two brain cancer cell lines (c6 and DBTRG-05MG) were used in the anti-proliferation assay. NBM-HD-3 treated cells were analyzed by flow cytometry in the cell cycle assay. The gene expression of NBM-HD-3 treated cells was determined by real-time quantitative PCR. HDAC enzyme assay, confocal microscopy and Western blot assay were used to validate NMB-HD-3 as HDACi. Western blot assay was used for analyzing cell cycle modulation by PTEN and AKT. RESULTS: NBM-HD-3 was found to have potent anti-proliferative activity in brain cancer cells (rat C6 glioma and human DBTRG-05MG glioblastoma). Western blot analysis and HDAC enzyme assay indicated that NBM-HD-3 was an HDAC inhibitor. The Western blot data exhibited increased levels of p21, Ac-histone 3, Ac-histone 4, and Ac-tubulin after brain cancer cells being treated with NBM-HD-3. NBM-HD-3 also affected the cell cycle regulators such as p21 and cyclin B1. In the study for its anticancer mechanism, NBM-HD-3 was found to increase PTEN and AKT protein levels significantly, while decreasing p-PTEN and p-AKT levels markedly. CONCLUSION: This study demonstrated that the novel compound, NBM-HD-3, is a potent HDAC inhibitor. It produces anticancer activity through modulation of PTEN and AKT in brain cancer cells.

Decreased protein synthesis of Hsp27 associated with cellular toxicity in a cell model of Machado-Joseph disease.

Machado-Joseph disease is an autosomal dominant spinocerebellar degeneration caused by the expansion of a polyglutamine tract within the gene product, ataxin-3. We have previously shown that increased oxidative stress and decreased expression of Hsp27 may be contributory factors to the disease progression. In this study, we utilized neuroblastoma SK-N-SH cells stably transfected with full-length expanded ataxin-3 to further investigate the mechanism(s) resulting in the decreased expression of Hsp27. Results from 35S-methionine pulse-chase labeling and protein degradation assays revealed that decreased Hsp27 in mutant MJD cells is due to defects in protein synthesis. Our results further demonstrated that Hsp27 degradation is independent of the proteasome degradation pathway. In addition, we showed that overexpression of Hsp27 desensitizes mutant MJD cells to apoptotic stress. Taken together, these findings provide the first evidence that expanded ataxin-3 interferes with Hsp27 synthesis, which may contribute to the impairment of the cells' ability to respond to stresses and trigger the progression of this late-onset disease.