Polysomnographic characteristics and predictors of positional obstructive sleep apnea in Japanese elderly

Sleep and Biological Rhythms - Sleep problems and obstructive sleep apnea (OSA) increase with age and disturb life in old age. Positional therapy is one option to treat OSA, but the differences in...     

Comparative metabolomics of Japanese Black cattle beef and other meats using gas chromatography–mass spectrometry

Progress in metabolomic analysis now allows the evaluation of food quality. This study aims to identify the metabolites in meat from livestock using a metabolomic approach. Using gas chromatography–mass spectrometry (GC/MS), many metabolites were reproducibly detected in meats, and distinct differences between livestock species (cattle, pigs, and chickens) were indicated. A comparison of metabolites between tissues types (muscle, intramuscular fat, and intermuscular fat) in marbled beef of Japanese Black cattle revealed that most metabolites are abundant in the muscle tissue. Several metabolites (medium-chain fatty acids, etc.) involved in triacylglycerol synthesis were uniquely detected in fat tissue. Additionally, the results of multivariate analysis suggest that GC/MS analysis of metabolites can distinguish between cattle breeds. These results provide useful information for the analysis of meat quality using GC/MS-based metabolomic analysis.

ABBREVIATIONS: GC/MS: gas chromatography-mass spectrometry; NMR: nuclear magnetic resonance; MS: mass spectrometry; IS: 2-isopropylmalic acid; MSTFA: N-Methyl-N-trimethylsilyltrifluoroacetamide; CV: coefficient of variation; TBS: Tris-buffered saline; MHC: myosin fast type; PCA: principal component analysis; OPLS-DA: orthogonal partial least-squares discriminant analysis; O2PLS: two-way orthogonal partial least-squares     

Delayed sleep/wake rhythm and excessive daytime sleepiness correlate with decreased daytime brain activity during cognitive task in university students

Insufficient sleep and irregular sleep/wake rhythm are common problems among university students. We investigated the effect of sleep/wake rhythm and excessive daytime sleepiness (EDS) on the cortical oxygenation as measured by near-infrared spectroscopy (NIRS) and cognitive performance in university students. Peak- and integral values by a word fluency task were measured with NIRS. EDS was evaluated by the Epworth sleepiness scale (ESS), and performance function was evaluated using N-back task. Peak cerebral oxygenation was significantly correlated with ESS, bedtime, wake-up time, and median time of sleep. Accuracy on 2-back task was significantly correlated with integral value. Peak- and integral values were significantly lower, and bedtime and median time of sleep were significantly delayed in the EDS group than in the non-EDS group. EDS accompanied by delayed sleep/wake rhythm and short sleep duration may play an important role in decreasing daytime brain activity and cognitive performance.     

定量蛋白质组学研究揭示知母可缓解2型糖尿病模型大鼠肝脏代谢异常

2型糖尿病(type 2 diabetes mellitus, T2DM)是一种在全球范围内广泛存在的代谢性疾病,不及时治疗可能会引发众多危及生命的并发症。肝脏代谢在糖尿病发生发展的过程中扮演着至关重要的角色。目前已有报道中药知母用于缓解胰岛素抵抗及糖尿病,但其能否缓解糖尿病中肝脏代谢的异常仍有待深入研究。因此,提取了高脂饮食和化学药物链脲佐菌素(streptozotocin, STZ)诱导的2型糖尿病大鼠模型、知母提取物处理的2型糖尿病大鼠模型、高脂饮食大鼠模型以及正常饮食大鼠对照组的肝脏蛋白,通过基于质谱的定量蛋白质组学串联质量标签(tandem mass tag, TMT)标记技术获得定量蛋白质组数据。利用生物信息学软件对各组数据进行层次聚类分析及主成分分析,并以P<0.05,差异倍数(fold change)>1.5作为阈值标准进行火山图分析,发现知母提取物治疗组相较未治疗组与正常对照组更接近,表明肝脏组织定量蛋白质组数据能够反映知母提取物对2型糖尿病大鼠模型的治疗效果。筛选获得了表达水平与知母提取物治疗密切相关的关键蛋白簇。利用在线网站分析蛋白簇的GO功能与KEG...     

G(i)-mediated Cas tyrosine phosphorylation in vascular endothelial cells stimulated with sphingosine 1-phosphate: possible involvement in cell motility enhancement in cooperation with Rho-mediated pathways

Since blood platelets release sphingosine 1-phosphate (Sph-1-P) upon activation, it is important to examine the effects of this bioactive lipid on vascular endothelial cell functions from the viewpoint of platelet-endothelial cell interactions. In the present study, we examined Sph-1-P-stimulated signaling pathways related to human umbilical vein endothelial cell (HUVEC) motility, with a special emphasis on the cytoskeletal docking protein Crk-associated substrate (Cas). Sph-1-P stimulated tyrosine phosphorylation of Cas, which was inhibited by the G(i) inactivator pertussis toxin but not by the Rho inactivator C3 exoenzyme or the Rho kinase inhibitor Y-27632. Fyn constitutively associated with and phosphorylated Cas, suggesting that Cas tyrosine phosphorylation may be catalyzed by Fyn. Furthermore, upon HUVEC stimulation with Sph-1-P, Crk, through its SH2 domain, interacted with tyrosine-phosphorylated Cas, and the Cas-Crk complex translocated to the cell periphery (membrane ruffles), through mediation of G(i) (Fyn) but not Rho. In contrast, tyrosine phosphorylation of focal adhesion kinase, and formation of stress fibers and focal adhesion were mediated by Rho but not G(i) (Fyn). Finally, Sph-1-P-enhanced HUVEC motility, assessed by a phagokinetic assay using gold sol-coated plates and a Boyden's chamber assay, was markedly inhibited not only by pertussis toxin (or the Fyn kinase inhibitor PP2) but also by C3 exoenzyme (or Y-27632). In HUVECs stimulated with Sph-1-P, these data suggest the following: (i) cytoskeletal signalings may be separable into G(i)-mediated signaling pathways (involving Cas) and Rho-mediated ones (involving FAK), and (ii) coordinated signalings from both pathways are required for Sph-1-P-enhanced HUVEC motility. Since HUVECs reportedly express the Sph-1-P receptors EDG-1 (coupled with G(i)) and EDG-3 (coupled with G(13) and G(q)) and the EDG-3 antagonist suramin was found to block specifically Rho-mediated responses, it is likely that Cas-related responses following G(i) activation originate from EDG-1, whereas Rho-related responses originate from EDG-3.     

Mice lacking serum amyloid P component do not necessarily develop severe autoimmune disease

Interleukin-10 (IL-10) is a cytokine with many regulatory functions. In particular, IL-10 exerts neutralizing effect on other cytokines, and therefore IL-10 is thought to have important therapeutic implications. Recent reports suggest that IL-10 regulates not only immunocytes but also collagen and collagenase gene expression in fibroblasts. In this study, we investigated the effect of IL-10 on gene expression of extracellular matrix (ECM) proteins, such as type I collagen, fibronectin, and decorin, in human skin fibroblasts. Results of Northern blot analysis showed that both collagen I and fibronectin mRNAs were downregulated, while decorin gene expression was enhanced by IL-10 (10 ng/ml) time-dependently (6-24 h). alpha1(I) collagen and fibronectin mRNAs were decreased to one-third and one-fourth, respectively, by 50 ng/ml IL-10, whereas decorin mRNA was increased up to 2.7-fold by 50 ng/ml IL-10. Response to IL-10 by scleroderma fibroblasts was similar to that in normal dermal fibroblasts, with decreased expression levels of collagen and fibronectin and induced decorin mRNA levels. Transforming growth factor-beta (TGF-beta) is a crucial fibrogenic cytokine which upregulates the mRNA expression of collagen and fibronectin, whereas it downregulates decorin mRNA expression in fibroblasts. Monocyte chemoattractant protein-1 (MCP-1) has recently been shown to upregulate the type I collagen mRNA expression in cultured fibroblasts. We therefore examined whether IL-10 alters gene expression of ECM elicited by TGF-beta and MCP-1. Our results demonstrated that IL-10 downregulated the TGF-beta-elicited increase of mRNA expression of type I collagen and fibronectin, while partially recovering TGF-beta-elicited decrease of decorin expression in normal skin fibroblasts. By contrast, IL-10 did not alter the MCP-1-elicited upregulation of mRNA expression of either alpha1(I) collagen and decorin. Our data indicate that IL-10 differentially regulates TGF-beta and MCP-1 in the modulation of ECM proteins and therefore suggest that IL-10 plays a role in the regulation of tissue remodeling.     

Immature multipotent hemopoietic progenitors lacking long-term bone marrow-reconstituting activity in the aorta-gonad-mesonephros region of murine day 10 fetuses

Previous studies indicated that multipotent progenitors exist in early fetuses that do not contain long-term reconstituting (LTR) activity. However, it remained unclear whether these multipotent progenitors are committed to the hemopoietic lineage or are immature mesodermal cells or hemangioblasts. In this study, we have succeeded in enriching the multipotent progenitors that are capable of generating myeloid, T, and B cells in the LFA-1(-) subpopulation of TER-119(-)c-kit(+)CD45(+) cells from the aorta-gonad-mesonephros (AGM) region of day 10 fetuses. We found that these day 10 AGM LFA-1(-) cells do not show the LTR activity, whereas day 11 AGM LFA-1(-) cells do have such an activity. These results strongly suggest that multipotent progenitors lacking LTR activity emerge as CD45(+) hemopoietic progenitor cells in the AGM region on the 10th day of gestation, and such p-Multi mature into hemopoietic stem cells by acquiring LTR activity.     

Crystal structure of alkaline cellulase K: insight into the alkaline adaptation of an industrial enzyme

The crystal structure of the catalytic domain of alkaline cellulase K was determined at 1.9 A resolution. Because of the most alkaliphilic nature and it's highest activity at pH 9.5, it is used commercially in laundry detergents. An analysis of the structural bases of the alkaliphilic character of the enzyme suggested a mechanism similar to that previously proposed for alkaline proteases, that is, an increase in the number of Arg, His, and Gln residues, and a decrease in Asp and Lys residues. Some ion pairs were formed by the gained Arg residues, which is similar to what has been found in the alkaline proteases. Lys-Asp ion pairs are disfavored and partly replaced with Arg-Asp ion pairs. The alkaline adaptation appeared to be a remodeling of ion pairs so that the charge balance is kept in the high pH range.     

Signal transduction pathways mediated by glycoprotein Ia/IIa in human platelets: comparison with those of glycoprotein VI

Human platelets were activated either by glycoprotein (GP) Ia/IIa agonist (rhodocytin) or by a GPVI agonist (collagen-related peptide, CRP), and the intracellular signal transduction pathways were compared in the presence of various inhibitors. Rhodocytin isolated from Calloselasma rhodostoma venom was verified as a GPIa/IIa agonist, based on the inhibitory effects of three mAbs directed against GPIa. Platelet activation mediated by GPIa/IIa led to overt platelet aggregation, elevation of intracellular Ca2+, and tyrosine phosphorylation of several proteins, similar to that of GPVI. p72(syk) and phospholipase Cgamma2 (PLCgamma2) tyrosine phosphorylation were also observed with GPIa/IIa-mediated platelet aggregation, although they peaked slightly later than that of GPVI. In contrast to GPVI-mediated platelet activation, most of these phenomena induced by GPIa/IIa activation were markedly suppressed by acetylsalicylic acid (ASA) or cytochalasin D. These findings suggest that the requirements for thromboxane A2 (TXA2) production and actin polymerization, which are the characteristics of collagen-induced platelet activation, are derived from the GPIa/IIa-mediated signal transduction, but not from that of GPVI.