Methylxanthine Derivative-Rich Cacao Extract Suppresses Differentiation of Adipocytes through Downregulation of PPARγ and C/EBPs

Abstract Cacao extract (CE) consumption has beneficial effects on human health, such as lowering the risk of obesity. However, the underlying molecular mechanism for the anti-obesity effect of CE remains incompletely understood. Here, we used a 50% aqueous alcohol extract of cacao mass, which is rich in methylxanthine derivatives (about 11%) and poor in flavan-3-ols (less than 1%), and assessed the suppression effects of this extract on adipocyte differentiation to investigate the anti-obesity mechanism. CE dose-dependently decreased fat accumulation in 3T3-L1 cells without affecting cell viability. CE also dose-dependently decreased the protein and gene expression levels of two adipogenesis-related transcription factors, peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer-binding proteins (C/EBPs). Moreover, CE decreased protein expression levels of sterol regulatory element-binding protein 1 (SREBP1) and its downstream fatty acid synthase (FAS), which was accompanied by the retained localization of SREBP1 in the cytoplasm of 3T3-L1 cells. After ICR mice were fed a diet containing 1% CE for 1 wk, their white adipose tissue weight was lower, whereas their brown adipose tissue weight was higher compared with those of control animals. Additionally, the protein expression levels of PPARγ, C/EBPs, SREBP1, and FAS in the white adipose tissue of these mice were also lower than those in control animals. In contrast, diet supplementation with CE induced higher levels of phosphorylated AMP-activated protein kinase (AMPK) and its downstream acetyl-CoA carboxylase. In conclusion, methylxanthine derivative-rich CE decreases fat accumulation in adipocytes by downregulating the expression of the adipocyte differentiation master regulators through the activation of AMPK.ArticleJournal of Nutritional Science and Vitaminology. 64(2): 151-160. (2018)journal articl

An analysis method for flavan-3-ols using high performance liquid chromatography coupled with a fluorescence detector

Procyanidins belong to a family of flavan-3-ols, which consist of monomers, (+)-catechin and (-)-epicatechin, and their oligomers and polymers, and are distributed in many plant-derived foods. Procyanidins are reported to have many beneficial physiological activities, such as antihypertensive and anticancer effects. However, the bioavailability of procyanidins is not well understood owing to a lack of convenient and high-sensitive analysis methods. The aim of this study was to develop an improved method for determining procyanidin content in both food materials and biological samples. High performance liquid chromatography (HPLC) coupled with a fluorescence detector was used in this study. The limits of detection (LODs) of (+)-catechin, (-)-epicatechin, procyanidin B2, procyanidin C1, and cinnamtannin A2 were 3.0 x 10(-3) ng, 4.0 x 10(-3) ng, 14.0 x 10(-3) ng, 18.5 x 10(-3) ng, and 23.0 x 10(-3) ng, respectively; the limits of quantification (LOQs) were 10.0 x 10(-3) ng, 29.0 x 10(-3) ng, 28.5 x 10(-3) ng, 54.1 x 10(-3) ng, and 115.0 x 10(-3) ng, respectively. The LOD and LOQ values indicated that the sensitivity of the fluorescence detector method was around 1000 times higher than that of conventional HPLC coupled with a UV-detector. We applied the developed method to measure procyanidins in black soybean seed coat extract (BE) prepared from soybeans grown under three different fertilization conditions, namely, conventional farming, basal manure application, and intertillage. The amount of flavan-3-ols in these BEs decreased in the order intertillage > basal manure application > conventional farming. Commercially available BE was orally administered to mice at a dose of 250 mg/kg body weight, and we measured the blood flavan-3-ol content. Data from plasma analysis indicated that up to the tetramer oligomerization, procyanidins were detectable and flavan-3-ols mainly existed in conjugated forms in the plasma. In conclusion, we developed a highly sensitive and convenient analytical method for the analysis of flavan-3-ols, and applied this technique to investigate the bioavailability of flavan-3-ols in biological samples and to measure flavan-3-ol content in food material and plants

Meiotic gene silencing complex MTREC/NURS recruits the nuclear exosome to YTH-RNA-binding protein Mmi1.

Accurate target recognition in transcript degradation is crucial for regulation of gene expression. In the fission yeast Schizosaccharomyces pombe, a number of meiotic transcripts are recognized by a YTH-family RNA-binding protein, Mmi1, and selectively degraded by the nuclear exosome during mitotic growth. Mmi1 forms nuclear foci in mitotically growing cells, and the nuclear exosome colocalizes to such foci. However, it remains elusive how Mmi1 and the nuclear exosome are connected. Here, we show that a complex called MTREC (Mtl1-Red1 core) or NURS (nuclear RNA silencing) that consists of a zinc-finger protein, Red1, and an RNA helicase, Mtl1, is required for the recruitment of the nuclear exosome to Mmi1 foci. Physical interaction between Mmi1 and the nuclear exosome depends on Red1. Furthermore, a chimeric protein involving Mmi1 and Rrp6, which is a nuclear-specific component of the exosome, suppresses the ectopic expression phenotype of meiotic transcripts in red1Δ cells and mtl1 mutant cells. These data indicate that the primary function of MTREC/NURS in meiotic transcript elimination is to link Mmi1 to the nuclear exosome physically

Adsorption and removal of strontium in aqueous solution by synthetic hydroxyapatite

Hydroxyapatite (HAP) is a main mineral constituent of bone and tooth and has an outstanding biocompatibility. HAP is a possible sorbent for heavy metals in wastewater due to its high adsorption capacity and low water solubility. We developed a removal system of 90Sr from aqueous solution by HAP column procedure. More than 90 % of 90Sr was adsorbed and removed from the 90Sr containing solution. Divalent cations, Ca2+, had little effect on the removal of 90Sr up to a concentration of 1 mmol L−1. This clearly indicates that the HAP column technique is advantageous with respect to the capacity to adsorb 90Sr from water present in the environment

Caffeine-Stimulated Intestinal Epithelial Cells Suppress Lipid Accumulation in Adipocytes

Caffeine is a methylxanthine derived from plant foods such as coffee beans and tea leaves, and has multiple biological activities against physiological response and several diseases. Although there are some reports about the direct effect of caffeine against anti-lipid accumulation in vitro, the effect of caffeine on lipid accumulation in adipocytes through stimulating intestinal epithelial cells is unknown. Since direct treatment with caffeine to 3T3-L1 cells did not affect lipid accumulation, we determined whether caffeine-stimulated intestinal epithelial Caco-2 cells influence the lipid accumulation in 3T3-L1 adipocytes. Caco-2 cells were cultured on a transwell insert with or without caffeine for 24 h. Subsequently, the basolateral component of the Caco-2 cell culture on the transwell was collected and termed caffeine-conditioning medium (CCM). When 3T3-L1 adipocytes were incubated with CCM, CCM decreased lipid accumulation and suppressed gene expression of proliferator activated receptor (PPAR) γ and CCAAT/enhancer binding protein (C/EBP) α in 3T3-L1 adipocytes. Furthermore, CCM decreased the expression of C/EBPβ and C/EBPδ at the protein level, but not at the mRNA level. We observed that a proteasome inhibitor, MG132, inhibited CCM-caused down-expression of C/EBPβ and C/EBPδ proteins, and that CCM promoted the ubiquitination level of C/EBPβ and C/EBPδ proteins. Protein microarray analysis showed caffeine suppresses the secretion of inflammatory cytokines, interleukin-8 and plasminogen activator inhibitor-1 from Caco-2 cells. These results suggest that caffeine indirectly suppresses lipid accumulation in 3T3-L1 adipocytes through decreasing secretion of inflammatory cytokines from Caco-2 cells.ArticleJournal of Nutritional Science and Vitaminology. 63(5): 331-338. (2017)journal articl

フルコナゾールの眼内動態およびその網膜におよぼす影響

取得学位 : 博士（医学）, 学位授与番号 : 医博乙第1335号, 学位授与年月日：平成7年4月19日,学位授与年：199

Gestational Outcomes and Birth Weight in Japanese Women at the Upper and Lower limits of the Normal BMI range

To examine the outcome of gestational blood pressure and birth weight in women with normal pre-pregnancy BMI (18.5-25 kg/m2) who are at the lower and upper limits of this range, i.e., slightly underweight or slightly overweight. Overall, 2,038 Japanese women with low -risk who had delivered during January 2014–December 2016 were classified according to their pre-pregnancy BMI: underweight (< 18.5 kg/m2), slightly underweight (18.5≤BMI<21 kg/m2), normal (21≤BMI<23 kg/m2), slightly overweight (23≤BMI<25 kg/m2) and overweight (≤ 25 kg/m2). Their blood pressure during each trimester and birth weight was evaluated. The slightly overweight group showed a significantly higher blood pressure than the underweight and slightly underweight groups. Birth weight was lower in the slightly underweight than in the slightly overweight group (p<0.01). The incidence rate of “heavy for dates” (HFD) infants was significantly higher in the slightly overweight and overweight groups than in the other groups (p<0.05 and p<0.01, respectively). Weight gain of < 7 kg significantly increased the rate of “light for dates” (LFD) infants, while a weight gain of ≥13 kg significantly increased the rate of HFD infants (p<0.05 and p<0.01, respectively). Blood pressure during pregnancy was ssociated with pre-pregnancy BMI. The birth weight of infants of low-risk pregnant women is affected by both pre-pregnancy BMI and gestational weight gain

A Practice of the Laboratory Course Using a Personal Spectrometer and Learning Management System

学生実験は，限られた授業時間，実験作業スペース，限られた数の機器など，いくつかの制約の下で行われている。これらの制約を緩和するために，予習用のコンテンツを学習管理システム（LMS）でオンライン公開した。2017年度前期より，学生一人ひとりが利用できる計測機器とタブレットを導入した。その後，アプリの改良を重ね，貸出用のタブレットではなく，学生が自分のスマートフォンを利用できるようになった。2022年度前期には，学生実験に一通りの方法が確立した。また，今後の改良点を模索するためにも学生実験終了後にアンケートを取った。本稿では，学生実験の概要，アンケート結果について報告する。Laboratory courses are conducted under some constraints, such as limited class hours, insufficient experimental workspace, and limited numbers of instruments. We released online preparatory content on the learning management system (LMS) to alleviate these restrictions. We introduced a measurement device and a tablet available to each student in the first semester of 2017. The measurement application has improved since then, and now students can use their own smartphones instead of tablets. An appropriate method for our laboratory course was completed in the first semester of 2022. In addition, a questionnaire was taken for further improvements after the laboratory course was finished. In this paper, we report the outline of the laboratory course and the questionnaire results