Role of the C-terminal region of mouse inducible Hsp72 in the recognition of peptide substrate for chaperone activity

AbstractHere, we produced the C-terminal truncation variants of mouse inducible heat shock protein 72 (Hsp72) to elucidate the regulatory role of the C-terminal helical lid of Hsp70 for substrate recognition. All of the truncation variants containing the substrate binding domain bound a short-length peptide substrate CLLLSAPRR. When a large mass reduced carboxymethyl α-lactalbumin (RCMLA) as a substrate was used in gel filtration experiment, we observed the complex formation only for the truncation variants containing the long α-helix C in the helical lid. However, RCMLA binding occurred even for the variants lacking α-helix C when their C-terminal region was anchored onto a solid phase. Together with the finding that helix C is involved in the self-association of Hsp70, our present data suggest that the C-terminal region of Hsp70 modulates the substrate recognition and its kinetics may be substrate-mass dependent

糖尿病患者と健常者におけるR-R間隔変動係数は運動中の循環応答を反映するか?

糖尿病患者と健常者のR-R間隔変動係数(CVR-R)と運動時における循環応答との関連を検討した。対象は2型糖尿病患者8名と,年齢をマッチさせた健常男性8名とした。対象者に自転車エルゴメータを用いた漸増負荷を行い,最大酸素摂取量(・VO2max)と換気性作業閾値(VT)を算出した。次に日を改めて,80%VTに相当する負荷強度で一定負荷運動を行わせた。その後,安静時におけるCVR-Rと,一定負荷運動における酸素摂取と心拍数の時定数を算出した。その結果,1)CVR-Rと・VO2maxはDM群で健常群と比較して低下していた。また,tau HRとtau・VO2はDM群で延長していた。2)tau・VO2とtau HRは二群共に正の相関を,CVR-Rとtau ・VO2は二群共に負の相関を認めた。2・VO2maxとtau HR,・VO2maxとtau・VO2は健常群のみ負の相関を認めた。以上の結果から,CVR-Rは運動に対する循環応答を反映する指標になる可能性が示唆された。また,先行研究において,健常者では運動開始時における循環応答特性は全身持久力を反映するものであることが示唆されているが,本研究では糖尿病患者においては関連を認めないことが明らかとなった。OBJECTIVE: We investigated the relation of the coefficient of variation of the R-R intervals in diabetic patients and healthy subjects, and the cardiovascular responses during exercise. RESEARCH DESIGN AND METHOD: The subjects were 8 males with type 2 diabetes mellitus, and 8 age-matched healthy nondiabetic males (healthy controls). All subjects performed an incremental test on a bicycle ergometer at a work rate of 15 Watt・min-1 to determine the maximum oxygen uptake and to calculate ventilatory threshold. Subsequently, on another day, they all performed a constant-load exercise at a work rate chosen to elicit an oxygen uptake equivalent to 800f their individual the ventilatory threshold. The coefficient of variation of the R-R intervals (CVR-R) was calculated from the electrocardiogram at rest and used as an index of autonomic nerve function. The time constant (tau) and steady state level of the kinetic response for oxygen uptake (VO2) and heart rate (HR) were calculated using a mono-exponential model under constant- load exercise. RESULTS: 1) CVR-R andVO2max were significantly lower in the diabetic patients than in the healthy controls. Tau HR and tauVO2 were significantly longer in the diabetic patients than in the healthy controls. 2) TauVO2 and tau HR were significantly positively correlated in both groups, whereas CVR-R and tau HR, and tauVO2 were significantly negatively correlated in both groups. 3)VO2max and tau HR, and tauVO2 were significantly negatively correlated only in the healthy controls. CONCLUSIONS: These results suggest that CVR-R may reflect the characteristics of cardiovascular responses to exercise. However, though some previous studies have postulated that these characteristics of cardiovascular responses to exercise reflect cardiorespiratory endurance in healthy controls, our study confirmed no such correlation in diabetic patients

Protocol for Obtaining Mouse iPS-RPE

Purpose To establish a novel protocol for differentiation of retinal pigment epithelium (RPE) with high purity from mouse induced pluripotent stem cells (iPSC). Methods Retinal progenitor cells were differentiated from mouse iPSC, and RPE differentiation was then enhanced by activation of the Wnt signaling pathway, inhibition of the fibroblast growth factor signaling pathway, and inhibition of the Rho-associated, coiled-coil containing protein kinase signaling pathway. Expanded pigmented cells were purified by plate adhesion after Accutase® treatment. Enriched cells were cultured until they developed a cobblestone appearance with cuboidal shape. The characteristics of iPS-RPE were confirmed by gene expression, immunocytochemistry, and electron microscopy. Functions and immunologic features of the iPS-RPE were also evaluated. Results We obtained iPS-RPE at high purity (approximately 98%). The iPS-RPE showed apical-basal polarity and cellular structure characteristic of RPE. Expression levels of several RPE markers were lower than those of freshly isolated mouse RPE but comparable to those of primary cultured RPE. The iPS-RPE could form tight junctions, phagocytose photoreceptor outer segments, express immune antigens, and suppress lymphocyte proliferation. Conclusion We successfully developed a differentiation/purification protocol to obtain mouse iPS-RPE. The mouse iPS-RPE can serve as an attractive tool for functional and morphological studies of RPE

Physical properties of the Dome Fuji deep ice core (review)

Recent results of physical analyses of the Dome Fuji ice core are summarized with special attention to new methods introduced in the present studies. Microphysical processes which affect the ice core records are reviewed to better understand the paleoclimatic and paleoenvironmental signals stored

Association of glucocorticoid doses and emotional health in lupus low disease activity state (LLDAS): a cross-sectional study

Background While survival of systemic lupus erythematosus (SLE) patients has improved substantially, problems remain in the management of their emotional health. Medium to high-dose glucocorticoid doses are known to worsen emotional health; the effect is unclear among patients receiving relatively low-dose glucocorticoids. This study aims to investigate the association between low glucocorticoid doses and emotional health in lupus low disease activity state (LLDAS). Methods This cross-sectional study drew on data from SLE patients in 10 Japanese institutions. The participants were adult patients with SLE duration of >= 1 year who met LLDAS criteria at the study visit from April 2018 through September 2019. The exposure was the daily glucocorticoid dose (mg oral prednisolone). The outcome was the emotional health score of the lupus patient-reported outcome scale (range: 0 to 100). Multiple linear regression analysis was performed with adjustment for confounders including disease-related damage, activity, and psychotropic drug use. Results Of 192 patients enrolled, 175 were included in the analysis. Their characteristics were as follows: female, 89.7%; median age, 47 years (interquartile range (IQR): 37.0, 61.0). Median glucocorticoid dose was 4.0 mg (IQR 2.0, 5.0), and median emotional health score 79.2 (IQR 58.3, 91.7). Multiple linear regression analysis showed daily glucocorticoid doses to be associated with worse emotional health (beta coefficient = - 2.54 [95% confidence interval - 4.48 to - 0.60], P = 0.01). Conclusions Daily glucocorticoid doses were inversely associated with emotional health among SLE patients in LLDAS. Further studies are needed to determine whether glucocorticoid tapering leads to clinically significant improvements in emotional health

Protein 4.1B Contributes to the Organization of Peripheral Myelinated Axons

Neurons are characterized by extremely long axons. This exceptional cell shape is likely to depend on multiple factors including interactions between the cytoskeleton and membrane proteins. In many cell types, members of the protein 4.1 family play an important role in tethering the cortical actin-spectrin cytoskeleton to the plasma membrane. Protein 4.1B is localized in myelinated axons, enriched in paranodal and juxtaparanodal regions, and also all along the internodes, but not at nodes of Ranvier where are localized the voltage-dependent sodium channels responsible for action potential propagation. To shed light on the role of protein 4.1B in the general organization of myelinated peripheral axons, we studied 4.1B knockout mice. These mice displayed a mildly impaired gait and motility. Whereas nodes were unaffected, the distribution of Caspr/paranodin, which anchors 4.1B to the membrane, was disorganized in paranodal regions and its levels were decreased. In juxtaparanodes, the enrichment of Caspr2, which also interacts with 4.1B, and of the associated TAG-1 and Kv1.1, was absent in mutant mice, whereas their levels were unaltered. Ultrastructural abnormalities were observed both at paranodes and juxtaparanodes. Axon calibers were slightly diminished in phrenic nerves and preterminal motor axons were dysmorphic in skeletal muscle. βII spectrin enrichment was decreased along the axolemma. Electrophysiological recordings at 3 post-natal weeks showed the occurrence of spontaneous and evoked repetitive activity indicating neuronal hyperexcitability, without change in conduction velocity. Thus, our results show that in myelinated axons 4.1B contributes to the stabilization of membrane proteins at paranodes, to the clustering of juxtaparanodal proteins, and to the regulation of the internodal axon caliber

セイタイ ボウギョ ニ オケル マウス ネツ ショック タンパクシツ 72 ノ C マッタン リョウイキ ノ ヤクワリ ニ カンスル ケンキュウ

京都大学0048新制・課程博士博士(農学)甲第13113号農博第1618号新制||農||941(附属図書館)学位論文||H19||N4239(農学部図書室)UT51-2007-H386京都大学大学院農学研究科食品生物科学専攻(主査)教授 北畠 直文, 教授 吉川 正明, 教授 河田 照雄学位規則第4条第1項該当Doctor of Agricultural ScienceKyoto UniversityDA