遷移金属酸化物のスピン構造と物性の理論的研究

13301甲第4228号博士（理学）金沢大学博士論文本文Ful

遷移金属酸化物のスピン構造と物性の理論的研究

13301甲第4228号博士（理学）金沢大学博士論文要旨Abstrac

Nutrient Condition in the Microenvironment Determines Essential Metabolisms of CD8(+) T Cells for Enhanced IFN gamma Production by Metformin

Metformin (Met), a first-line drug for type 2 diabetes, lowers blood glucose levels by suppressing gluconeogenesis in the liver, presumably through the liver kinase B1-dependent activation of AMP-activated protein kinase (AMPK) after inhibiting respiratory chain complex I. Met is also implicated as a drug to be repurposed for cancers; its mechanism is believed identical to that of gluconeogenesis inhibition. However, AMPK activation requires high Met concentrations at more than 1 mM, which are unachievable in vivo. The immune-mediated antitumor response might be the case in a low dose Met. Thus, we proposed activating or expanding tumor-infiltrating CD8(+) T cells (CD8TILs) in a mouse model by orally administering Met in free drinking water. Here we showed that Met, at around 10 mu M and a physiologically relevant concentration, enhanced production of IFN gamma,TNF alpha and expression of CD25 of CD8(+) T cells upon TCR stimulation. Under a glucose-rich condition, glycolysis was exclusively involved in enhancing IFN gamma production. Under a low-glucose condition, fatty acid oxidation or autophagy-dependent glutaminolysis, or both, was also involved. Moreover, phosphoenolpyruvate carboxykinase 1 (PCK1), converting oxaloacetate to phosphoenolpyruvate, became essential. Importantly, the enhanced IFN gamma production was blocked by a mitochondrial ROS scavenger and not by an inhibitor of AMPK. In addition, IFN gamma production by CD8TILs relied on pyruvate translocation to the mitochondria and PCK1. Our results revealed a direct effect of Met on IFN gamma production of CD8(+) T cells that was dependent on differential metabolic pathways and determined by nutrient conditions in the microenvironment

成熟マウス心筋細胞の単離と模擬虚血モデルの作成

Cultured cells are used for biochemical and physiological investigation of organ system, because they can supply relatively uniform experimental models. Cardiac myocytes have been also isolated and cultured for the use of heart studies. However, adult cardiac myocytes are sensitive to isolation condition and most studies utilized fetal or neonatal cardiac myocytes. Recently, several groups isolated adult cardiac myocytes from canine, rabbit and rat successfully. In this report, we tried to isolate myocytes from adult mice and to establish oxidative stress model of adult mouse myocytes. Hearts were excised and retro-perfused through aorta by collagenase solution following physiological salt solution containing uncoupler of excitation-contraction coupling, butanedione. Thereafter, hearts were minced in 1-2mm^3 cube and myocytes were isolated by mechanical agitation. Isolated cells were transferred onto culture dishes pre-coated with laminine. Cells were cultured with Dulbecco\u27s modified Eagle medium containing 10% fetal bovine serum and bromodeoxyuridine. Isolated myocytes showed rod shape with striation, typical morphology of adult cardiac myocytes. They attached on laminine-coated dishes and survived over 5 days without proliferation of contaminated noncardiac myocytes. When cells were cultured more than a week, they changed their shape to spindle type and started spontaneous beating. To mimic oxidative stress to hearts, we added hydrogen peroxide to myocyte cultures. Myocytes released lactate dehydrogenase into culture medium dose and time dependently. These data suggest that we successfully isolated and cultured cardiac myocytes from adult mouse hearts. They showed similar characteristics to the heart in situ in oxidative stress model by hydrogen peroxide

Circadian production of melatonin in cartilage modifies rhythmic gene expression

Endochondral ossification, including bone growth and other metabolic events, is regulated by circadian rhythms. Herein, we provide evidence that melatonin has a direct effect on the circadian rhythm of chondrocytes. We detected mRNA expression of the genes which encode the melatonin-synthesizing enzymes AANAT (arylalkylamine N-acetyltransferase) and HIOMT (hydroxyindole O-methyltransferase), as well as the melatonin receptors MT1 and MT2 in mouse primary chondrocytes and cartilage. Production of melatonin was confirmed by mass spectrometric analysis of primary rat and chick chondrocytes. Addition of melatonin to primary mouse chondrocytes caused enhanced cell growth and increased expression of Col2a1, Aggrecan, and Sox9, but inhibited Col10a1 expression in primary BALB/c mouse chondrocytes. Addition of luzindole, an MT1 and MT2 antagonist, abolished these effects. These data indicate that chondrocytes produce melatonin, which regulates cartilage growth and maturation via the MT1 and MT2 receptors. Kinetic analysis showed that melatonin caused rapid upregulation of Aanat, Mt1, Mt2, and Pthrp expression, followed by Sox9 and Ihh. Furthermore, expression of the clock gene Bmal1 was induced, while that of Per1 was downregulated. Chronobiological analysis of synchronized C3H mouse chondrocytes revealed that melatonin induced the cyclic expression of Aanat and modified the cyclic rhythm of Bmal1, Mt1, and Mt2. In contrast, Mt1 and Mt2 showed different rhythms from Bmal1 and Aanat, indicating the existence of different regulatory genes. Our results indicate that exogenous and endogenous melatonin work in synergy in chondrocytes to adjust rhythmic expression to the central suprachiasmatic nucleus clock

Association of skipping breakfast and short sleep duration with the prevalence of metabolic syndrome in the general Japanese population : Baseline data from the Japan Multi-Institutional Collaborative cohort study

The purpose of the study was to investigate sex-specific associations of skipping breakfast and short sleep duration with metabolic syndrome (MetS) and their interaction. We analyzed baseline data of 14,907 men and 14,873 women aged 35–69 years, who participated in the Japan Multi-Institutional Collaborative Cohort Study from 2005. MetS was diagnosed using a modification of the National Cholesterol Education Program Adult Treatment Panel III revised definition (NCEP-R 2005), using body mass index instead of waist circumference. Breakfast consumption was classified into two categories: ≥6 days/week (consumers) or <6 days/week (skippers). Sleep duration was classified into three categories: <6h, 6 to <8 h, and ≥8 h/day. Multivariate logistic regression analysis was performed to estimate odds ratios (ORs) and 95 % confidence intervals (CIs) and examine the presence of interaction. In men, skipping breakfast and short sleep duration were independently associated with an increased prevalence of MetS (OR 1.26, 95%CI 1.12–1.42 and OR 1.28, 95%CI 1.12–1.45, respectively), obesity, and components of MetS. However, no significant interaction was observed between skipping breakfast and short sleep duration. In women, skipping breakfast and short sleep duration were associated with an increased prevalence of obesity, but not with MetS. These findings indicate that breakfast consumption and moderate sleep duration may be associated with a lower risk of MetS, particularly in men

The effect of isoflavone-daidzein oral medication on cutaneous wound healing in female ovariectomized mice

This study investigated the influence of oral administration of isoflavone-daidzein on the cutaneous wound healing process in female ovariectomized mice. Eight-week-old female mice were divided into groups of ovariectomized mice and mice administered daidzein after an ovariectomy. Two full-thickness wounds on the dorsum were made in mice in both groups. There was no significant difference between wound areas of the two groups from wounding to healing during 15 days. The area in the group administered daidzein tended to be smaller than that in the ovariectomized group during the inflammatory phase 4 and 5 days after wounding . The rate of re-epithelialization in the group administered daidzein tended to be higher than that in the ovariectomized group in the inflammatory phase on day 3 (40.7 ± 17.6% and 21.0 ± 16.8%, respectively). Therefore, the administration of daidzein under lack of estrogen is expected to reduce the inflammation period and promote re-epithelialization. この研究は、卵巣摘出した雌マウスに皮膚創傷を作製し、経口投与したイソフラボン の一種であるダイゼインが、創傷治癒にどのような影響を与えるかを観察したもので ある。8 週令の雌マウスを卵巣摘出群と卵巣摘出し創作製した後にダイゼインを与え た2 群に分けた。両群共、卵巣摘出後、ダイゼインを含まない精製飼料で２週間飼育 後に、左右の背部に直径4mm の皮膚全層欠損層を作製した。創作製後、ダイゼインを 含まない飼料とダイゼインを含む飼料で2 週間飼育した。ダイゼインは、飼料1g に 0.01mg 含むように作製した。両群の創面積は、2 週間の間の毎日において、有意差は 見られなかった。しかし、炎症期である創作製後4 と5 日では、ダイゼイン食で飼育 した群が無ダイゼイン食で飼育した群が、やや創面積が小さい傾向がみられた（それ ぞれ、p 値が0.061、0.083 であった）。創作製後の3 日での、再上皮化の割合は、ダイゼイン群で40.7 ± 17.6%、無ダイゼイン群で21.0 ± 16.8%となり、ダイゼイ ン群はより上皮化が進んでいる傾向が見られた (p = 0.07)。これらの結果は、エス トロゲン欠乏状態で、ダイゼインの経口投与が、創傷治癒において、炎症を抑制し上 皮化を促進することを示唆している

Association of perceived stress and coping strategies with the renal function in middle-aged and older Japanese men and women

Elucidating the risk factors for chronic kidney disease is important for preventing end-stage renal disease and reducing mortality. However, little is known about the roles of psychosocial stress and stress coping behaviors in deterioration of the renal function, as measured by the estimated glomerular filtration rate (eGFR). This cross-sectional study of middle-aged and older Japanese men (n = 31,703) and women (n = 38,939) investigated whether perceived stress and coping strategies (emotional expression, emotional support seeking, positive reappraisal, problem solving, and disengagement) were related to the eGFR, with mutual interactions. In multiple linear regression analyses adjusted for age, area, lifestyle factors, and psychosocial variables, we found a significant inverse association between perceived stress and the eGFR in men (Ptrend = 0.02), but not women. This male-specific inverse association was slightly attenuated after adjustment for the history of hypertension and diabetes and was more evident in lower levels of emotional expression (Pinteraction = 0.003). Unexpectedly, problem solving in men (Ptrend < 0.001) and positive reappraisal in women (Ptrend = 0.002) also showed an inverse association with the eGFR. Perceived stress may affect the eGFR, partly through the development of hypertension and diabetes. The unexpected findings regarding coping strategies require the clarification of the underlying mechanisms, including the hormonal and immunological aspects

Seven-plus hours of daily sedentary time and the subsequent risk of breast cancer : Japan Multi-Institutional Collaborative Cohort Study

This study aimed to investigate the association between daily sedentary time and the risk of breast cancer (BC) in a large Japanese population. The participants were 36,023 women aged 35–69 years from the Japan Multi-Institutional Collaborative Cohort Study. Cox proportional hazards analysis was used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for BC incidence in relation to time spent sedentarily (categorical variables: <7 and ≥7 hours/day [h/d]). Additionally, the associations of BC incidence to the joint effect of sedentary time with each component of physical activity, such as leisure-time metabolic equivalents (METs), frequency of leisure-time physical activity, and daily walking time, were examined. During 315,189 person-years of follow-up, 554 incident cases of BC were identified. When compared to participants who spent <7 h/d sedentary, those who spent ≥7 h/d sedentary have a significantly higher risk of BC (HR, 1.36; 95% CI, 1.07–1.71). The corresponding HRs among participants who spent ≥7 h/d sedentary with more physical activity, such as ≥1 h/d for leisure-time METs, ≥3 days/week of leisure-time physical activity, and ≥1 h/d of daily walking were 1.58 (95% CI, 1.11–2.25), 1.77 (95% CI, 1.20–2.61), and 1.42 (95% CI, 1.10–1.83), respectively, compared with those who spent <7 h/d sedentary. This study found that spending ≥7 h/d of sedentary time is associated with the risk of BC. Neither leisure-time physical activity nor walking had a BC-preventive effect in those with ≥7 h/d of sedentary time