Identification of protease serine S1 family member 53 as a mitochondrial protein in murine islet beta cells

The aim of this study was to identify genes that are specifically expressed in pancreatic islet β-cells (hereafter referred to as β-cells). Large-scale complementary DNA-sequencing analysis was performed for 3,429 expressed sequence tags derived from murine MIN6 β-cells, through homology comparisons using the GenBank database. Three individual ESTs were found to code for protease serine S1 family member 53 (Prss53). Prss53 mRNA is processed into both a short and long form, which encode 482 and 552 amino acids, respectively. Transient overexpression of myc-tagged Prss53 in COS-7 cells showed that Prss53 was strongly associated with the luminal surfaces of organellar membranes and that it underwent signal peptide cleavage and N-glycosylation. Immunoelectron microscopy and western blotting revealed that Prss53 localized to mitochondria in MIN6 cells. Short hairpin RNA-mediated Prss53 knockdown resulted in Ppargc1a downregulation and Ucp2 and Glut2 upregulation. JC-1 staining revealed that the mitochondria were depolarized in Prss53-knockdown MIN6 cells; however, no change was observed in glucose-stimulated insulin secretion. Our results suggest that mitochondrial Prss53 expression plays an important role in maintaining the health of β-cells

YKL-40 secreted from adipose tissue inhibits degradation of type I collagen

Obesity is considered a chronic low-grade inflammatory status and the stromal vascular fraction (SVF) cells of adipose tissue (AT) are considered a source of inflammation-related molecules. We identified YKL-40 as a major protein secreted from SVF cells in human visceral AT. YKL-40 expression levels in SVF cells from visceral AT were higher than in those from subcutaneous AT. Immunofluorescence staining revealed that YKL-40 was exclusively expressed in macrophages among SVF cells. YKL-40 purified from SVF cells inhibited the degradation of type I collagen, a major extracellular matrix of AT, by matrix metalloproteinase (MMP)-1 and increased rate of fibril formation of type I collagen. The expression of MMP-1 in preadipocytes and macrophages was enhanced by interaction between these cells. These results suggest that macrophage/preadipocyte interaction enhances degradation of type I collagen in AT, meanwhile, YKL-40 secreted from macrophages infiltrating into AT inhibits the type I collagen degradation

Assessment Report of Doctoral Theses

Pd-Cer合金の規則構造と電子物性に関する研究[板倉]酸化物半導体を用いた食品評価用においセンサの研究[阿武]置換型ヘキサアルミネート系化合物の触媒特性と耐熱性厚膜の作製に関する研究[井上]ペロブスカイト型酸化物の酸素還元活性とガス拡散型酸素電極への応用[兵頭]ペロブスカイト型酸化物の酸素還元活性とガス拡散型酸素電極への応用[林信哉]LI_2型規則合金の相転移過程における逆位相境界の挙動に関する研究[松本]湿式法を用いる有機エレクトロルミネッセンス素子における材料設計[林清標]構造材料の粒界構造とその破壊強度に関する研究[森田]Refractive Index and Dispersion Characteristics of Oxide Glasses[藤野]An Application of Laser One-Photon Excited Fluorescence and Two-Photon Excited Fluorescence to Flowing System Aiming a Si8ngle Molecule Detection[宋]電子およびアルゴンイオン-炭化水素衝突によるフラブメントの生成機構[渡慶次]1,5-および1,7-アズレンキノン類の熱的付加反応に関する研究[厳]積層型[3.3] [3.3]オルトシクロファン類の合成とスルースペース相互作用に関する研究[三苫]Oxidative Cycloaddition of Thiophenes[李][3.3]オルトアントラセノファン類のDiels-Alder反応[馬彊]リチウムビームプローブを用いた周辺プラズマの密度分布と動揺に関する研究[森崎]レーザー分光法を用いたグロー放電プラズマのシース電界に関する研究[崔]レーザー光散乱による気体の圧力測定法の開発と産業プラズマへの適用[宋]レーザー位相差法を用いた高温プラズマ不安定性の実験的研究[門]Control of Porosity and Surface Functional Groups over Porous Carbons[河淵]表面張力対流の基礎的研究[安廣]CVD法による気相成長炭素繊維の生成に関する研究[藤本]一様静止磁場による液体金属の自然対流伝熱促進[田川]Growth and characterization of Single Crystals of Bi-based Oxides by a Floating Zone Method[符]水平コールドウォール型CVD装置内の熱流動に関する研究[田之上]超並列計算機AMPによる並列画像処理に関する研究[山元]主鎖に機能基を持つ高分子エレクトロルミネッセンス材料の研究[金]Synthesis and Evaluation of a Novel Anticancer Rhodacyanine Compound[古屋]精密プラズマ切断用アークジェットに関する研究[桜木