Biomedical Research
Online ISSN : 1880-313X
Print ISSN : 0388-6107
ISSN-L : 0388-6107
36 巻 , 6 号
選択された号の論文の7件中1~7を表示しています
Full Papers
  • Saiko FUJIMOTO, Masashi ISHIKAWA, Masatoshi NAGANO, Atsuhiro SAKAMOTO
    2015 年 36 巻 6 号 p. 347-355
    発行日: 2015/12/01
    公開日: 2015/12/22
    ジャーナル フリー
    Commonly used anesthetics adversely affect the developing brain, but the mechanisms remain unknown. We previously showed that the expressions of microRNAs (miRNAs) in major organs are affected by anesthetics. Therefore, we used TaqMan low-density array (TLDA) to analyze gene expression in the hippocampus of neonatal rats exposed to sevoflurane and performed behavioral tests after they reached adulthood to evaluate cognitive and memory function. Rat male pups at postnatal day 7 were exposed to 1.9% sevoflurane for 3 h, and the hippocampus-miRNA expression profile on postnatal day 8 was determined. Open field and fear conditioning tests conducted during postnatal weeks 7 and 8 indicated that sevoflurane-exposed rats, but not controls, exhibited anxiety-like disorders. TLDA analysis identified 20 differentially expressed miRNAs, which were not shared between postnatally and maturely sevoflurane-exposed rats. The level of rno-miR-632, which targets brain-derived neurotrophic factor and calcium channel, voltage-dependent, alpha 2/delta subunit 2, increased by 10-fold, indicating that exposure to sevoflurane during early neural development alters hippocampus-miRNA expression and may induce subsequent behavioral disorders.
  • Chika IKEDA-KUROSAWA, Hironori HIGASHIO, Masato NAKANO, Masatoshi OKUB ...
    2015 年 36 巻 6 号 p. 357-369
    発行日: 2015/12/01
    公開日: 2015/12/22
    ジャーナル フリー
    Noradrenaline (NA) is a catecholamine with multiple roles including as a hormone and a neurotransmitter. Cellular secretory activities are enhanced by adrenergic stimuli as well as by cholinergic stimuli. The present study aimed to determine which adrenoceptors play a role in controlling intracellular calcium ion ([Ca2+]i) level in acinar cells of rat lacrimal glands. Expression of mRNA for adrenoceptor subtypes in the acinar cells was assessed using RT-PCR. All types except α2c, β1, and β3 were detected. NA induced a [Ca2+]i increase with a biphasic pattern in the acinar cells. Removal of extracellular Ca2+ and use of Ca2+-channel blockers did not inhibit the NA-induced [Ca2+]i increases. In contrast, U73122 and suramin almost blocked these increases. The α1-adrenoceptor agonist phenylephrine induced a strong increase in [Ca2+]i. However, clonidine and isoproterenol failed to induce a [Ca2+]i increase. The peroxidase activity was quantified as a measure of mucin secretion. Ca2+-dependent exocytotic secretion of peroxidase was detected in rat lacrimal glands. The RT-PCR results showed that MUC1, MUC4, MUC5AC, MUC5B, and MUC16 were expressed in acinar cells. These findings indicated that NA activates α1-adrenoceptors, which were found to be the main receptors in Ca2+-related cell homeostasis and protein (including mucin) secretion in lacrimal glands.
  • Chieko IWAO, Yoshihiro SHIDOJI
    2015 年 36 巻 6 号 p. 371-381
    発行日: 2015/12/01
    公開日: 2015/12/22
    ジャーナル フリー
    Metabolic alternation in cancer cells is one of the most common characteristics that distinguish malignant cells from normal cells. Many studies have explained the Warburg hypothesis that cancer cells obtain more energy from aerobic glycolysis than mitochondrial respiration. Here, we show that a branched-chain C-20 polyunsaturated fatty acid, geranylgeranoic acid (GGA), induces upregulation of the cellular protein levels of TP53-induced glycolysis and apoptosis regulator (TIGAR) and synthesis of cytochrome c oxidase 2 (SCO2) in human hepatoma-derived HuH-7cells harboring the mutant TP53 gene, suggesting that GGA may shift an energetic state of the tumor cells from aerobic glycolysis to mitochondrial respiration. In addition, UPLC/TOF/MS-based metabolomics analysis supported the GGA-induced energetic shift, as it revealed that GGA induced a time-dependent increase in the cellular contents of fructose 6-phosphate and decrease of fructose 1,6-diphosphate. Furthermore, metabolomics analysis revealed that GGA rapidly induced spermine accumulation with slight decrease of spermidine. Taken together, the present study strongly suggests that GGA may shift HuH-7 cells from aerobic glycolysis to mitochondrial respiration through the immediate upregulation of TIGAR and SCO2 protein levels.
  • Naoto FUJITA, Hidemi FUJINO, Hiroki SAKAMOTO, Jyunya TAKEGAKI, Masatak ...
    2015 年 36 巻 6 号 p. 383-392
    発行日: 2015/12/01
    公開日: 2015/12/22
    ジャーナル フリー
    Patients with heart failure have limited exercise capacity due to not only the myocardial dysfunction but also skeletal muscle atrophy. However, the mechanisms and time course of protein degradation in skeletal muscle during heart failure remain unclear, and there is no established standard treatment. The purpose of the present study was to investigate the time course of major protein degradation pathways in skeletal muscle during heart failure. Four-week-old male Wistar rats were randomly assigned to heart failure induced by monocrotaline or control groups. At 14 and 21 days after monocrotaline injection, the lungs, heart, and gastrocnemius and soleus muscles were removed and analyzed. There was no significant difference in body weight between the groups at 14 days after monocrotaline injection. Although there were no morphological changes in the skeletal muscle of the monocrotaline group at this time point, ubiquitin-proteasome and macroautophagylysosome pathways were activated in the monocrotaline group. Additionally, the pathways were less strongly activated in the soleus muscle than in the gastrocnemius muscle. These results suggest that physical exercise that shifts to slow muscle characteristics should begin when there is no indication of skeletal muscle atrophy to prevent exercise intolerance with heart failure.
  • Yoichiro IKOMA, Hiroshi KIJIMA, Ryota MASUDA, Makiko TANAKA, Sadaki IN ...
    2015 年 36 巻 6 号 p. 393-402
    発行日: 2015/12/01
    公開日: 2015/12/22
    ジャーナル フリー
    Podoplanin is a 38 kDa transmembrane protein that is involved in cell migration and cancer cell invasion. Some studies have reported that podoplanin expression was correlated with poor prognosis in lung squamous cell carcinoma (SqCC). However, there have been no clinicopathological studies of podoplanin membrane expression and localization in lung SqCC. In this study, we focused on the intensity and localization of podoplanin membrane expression, and its clinicopathological significance for lung SqCC. Strong membrane expression of podoplanin was significantly associated with lymph node metastasis, lymphatic invasion, and histological differentiation. Cases with strong podoplanin expression at cell membrane showed better prognosis of lung SqCC (HR, 3.301). Peripheral localization of podoplanin was associated with tumor size, lymphatic invasion, and histological differentiation. Cases with peripheral podoplanin expression showed favorable prognosis of lung SqCC (HR, 2.830). Both strong membrane expression and peripheral expression of podoplanin were independent predictors of mortality of lung SqCC (HR, 2.869; HR, 2.443, respectively). The cases with strong or peripheral podoplanin expression showed better overall survival (P = 0.001, both). Podoplanin intensity is significantly associated with podoplanin localization (P < 0.001), and its correlation coefficient was 0.678. We concluded that podoplanin membrane expression, not only its localization, is a useful prognostic indicator of lung SqCC patients.
  • Yasukazu HOZUMI, Toshiaki TANAKA, Tomoyuki NAKANO, Hirooki MATSUI, Tak ...
    2015 年 36 巻 6 号 p. 403-409
    発行日: 2015/12/01
    公開日: 2015/12/22
    ジャーナル フリー
    Orotate phosphoribosyltransferase (OPRT) is engaged in de novo pyrimidine synthesis. It catalyzes oronitine to uridine monophosphate (UMP), which is used for RNA synthesis. De novo pyrimidine synthesis has long been known to play an important role in providing DNA/RNA precursors for rapid proliferative activity of cancer cells. Furthermore, chemotherapeutic drug 5-fluorouracil (5-FU) is taken up into cancer cells and is converted to 5-fluoro-UMP (FUMP) by OPRT or to 5-fluoro-dUMP (FdUMP) through intermediary molecules by thymidine phosphorylase. These 5-FU metabolites are misincorporated into DNA/RNA, thereby producing dysfunction of these information processing. However, it remains unclear how the subcellular localization of OPRT and how its variable expression levels affect the response to 5-FU at the cellular level. In this study, immunocytochemical analysis reveals that OPRT localizes to the Golgi complex. Results also show that not only overexpression but also downregulation of OPRT render cells susceptible to 5-FU exposure, but it has no effect on DNA damaging agent doxorubicin. This study provides clues to elucidate the cellular response to 5-FU chemotherapy in relation to the OPRT expression level.
  • Naoko KAIBARA, Ayase KOBORI, Ayako SEKIME, Kyoko MIYASAKA
    2015 年 36 巻 6 号 p. 411-415
    発行日: 2015/12/01
    公開日: 2015/12/22
    ジャーナル フリー
    We previously reported that ingestion of 60 mL of red wine or vodka prior to the ingestion of a pancake significantly inhibited the gastric emptying of the pancake in male subjects, but not in female subjects, and that the retention times of wine and vodka were significantly longer than those of the congener of red wine and mineral water in male subjects, whereas in female subjects the retention times of these four drinks did not differ significantly from one another. We hypothesized that the menstrual cycle may influence the gastric emptying of alcohol beverages. Here, we determined and compared the retention times of vodka and water in the stomach during the luteal phase and the follicular phase. Ten female healthy volunteers were studied. They recorded their basal body temperatures every day, and participated in the following experiments: each volunteer drank mineral water or vodka containing 14% alcohol (60 mL) during the low-temperature (follicular) phase as well as during the high-temperature (luteal) phase. The retention time of vodka was significantly longer than that of mineral water during the follicular phase, but no significant differences between the retention times of the two drinks were observed during the luteal phase. In conclusion, the menstrual cycle influences the gastric emptying rate of alcohol.
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