16 research outputs found

    Positive Regulation by GABABR1 Subunit of Leptin Expression through Gene Transactivation in Adipocytes

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    Background: The view that c-aminobutyric acid (GABA) plays a functional role in non-neuronal tissues, in addition to an inhibitory neurotransmitter role in the mammalian central nervous system, is prevailing, while little attention has been paid to GABAergic signaling machineries expressed by adipocytes to date. In this study, we attempted to demonstrate the possible functional expression of GABAergic signaling machineries by adipocytes. Methodology/Principal Findings: GABAB receptor 1 (GABABR1) subunit was constitutively expressed by mouse embryonic fibroblasts differentiated into adipocytes and adipocytic 3T3-L1 cells in culture, as well as mouse white adipose tissue, with no responsiveness to GABA BR ligands. However, no prominent expression was seen with mRNA for GABA BR2 subunit required for heteromeric orchestration of the functional GABABR by any adipocytic cells and tissues. Leptin mRNA expression was significantly and selectively decreased in adipose tissue and embryonic fibroblasts, along with drastically reduced plasma leptin levels, in GABA BR1-null mice than in wild-type mice. Knockdown by siRNA of GABA BR1 subunit led to significant decreases in leptin promoter activity and leptin mRNA levels in 3T3-L1 cells. Conclusions/Significance: Our results indicate that GABABR1 subunit is constitutively expressed by adipocytes to primarily regulate leptin expression at the transcriptional level through a mechanism not relevant to the function as a partner o

    Distress Detection in Subway Tunnel Images via Data Augmentation Based on Selective Image Cropping and Patching

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    Distresses, such as cracks, directly reflect the structural integrity of subway tunnels. Therefore, the detection of subway tunnel distress is an essential task in tunnel structure maintenance. This paper presents the performance improvement of deep learning-based distress detection to support the maintenance of subway tunnels through a new data augmentation method, selective image cropping and patching (SICAP). Specifically, we generate effective data for training the distress detection model by focusing on the distressed regions via SICAP. After the data augmentation, we train a distress detection model using the expanded training data. The new image generated based on SICAP does not change the pixel values of the original image. Thus, there is little loss of information, and the generated images are effective in constructing a robust model for various subway tunnel lines. We conducted experiments with some comparative methods. The experimental results show that the detection performance can be improved by our data augmentation

    Antigen Protease Activity on Intact or Tape-Stripped Skin Induces Acute Itch and T Helper Sensitization Leading to Airway Eosinophilia in Mice

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    Respiratory allergen sources such as house dust mites frequently contain proteases. In this study, we demonstrated that the epicutaneous application of a model protease antigen, papain, onto intact or tape-stripped ear skin of mice induced acute scratching behaviors and T helper (Th)2, Th9, Th17/Th22, and/or Th1 sensitization in a protease activity–dependent manner. The protease activity of papain applied onto the skin was also essential for subsequent airway eosinophilia induced by an intranasal challenge with low-dose papain. With tape stripping, papain-treated mice showed barrier dysfunction, the accelerated onset of acute scratching behaviors, and attenuated Th17/Th22 sensitization. In contrast, the protease activity of inhaled papain partially or critically contributed to airway atopic march responses in mice sensitized through intact or tape-stripped skin, respectively. These results indicated that papain protease activity on epicutaneous application through intact skin or skin with mechanical barrier damage is critical to the sensitization phase responses, including acute itch and Th sensitization and progression to the airway atopic march, whereas dependency on the protease activity of inhaled papain in the atopic march differs by the condition of the sensitized skin area. This study suggests that exogenous protease-dependent epicutaneous mechanisms are a target for controlling allergic sensitization and progression to the atopic march

    Reintroduction of H5N1 highly pathogenic avian influenza virus by migratory water birds, causing poultry outbreaks in the 2010-2011 winter season in Japan

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    H5N1 highly pathogenic avian influenza virus (HPAIV) was reintroduced and caused outbreaks in chickens in 2010-2011 winter season in Japan, which had been free from highly pathogenic avian influenza (HPAI) since 2007 when HPAI outbreaks occurred and were controlled. On October 14, 2010 at Lake Ohnuma, Wakkanai, the northernmost part of Hokkaido, Japan, H5N1 HPAIVs were isolated from fecal samples of ducks flying from their nesting lakes in Siberia. Since then, in Japan, H5N1 HPAIVs have been isolated from 63 wild birds in 17 prefectures and caused HPAI outbreaks in 24 chicken farms in 9 prefectures by the end of March in 2011. Each of these isolates was genetically closely related to the HPAIV isolates at Lake Ohnuma, and those in China, Mongolia, Russia, and Korea, belonging to genetic clade 2.3.2.1. In addition, these isolates were genetically classified into 3 groups, suggesting that the viruses were transmitted by migratory water birds through at least 3 different routes from their northern territory to Japan. These isolates were antigenic variants, which is consistent with selection in poultry under the immunological pressure induced by vaccination. To prevent the perpetuation of viruses in the lakes where water birds nest in summer in Siberia, prompt eradication of HPAIVs in poultry is urgently needed in Asian countries where HPAI has not been controlled

    The Pituitary Function of Androgen Receptor Constitutes a Glucocorticoid Production Circuit▿

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    Androgen receptor (AR) mediates diverse androgen actions, particularly reproductive processes in males and females. AR-mediated androgen signaling is considered to also control metabolic processes; however, the molecular basis remains elusive. In the present study, we explored the molecular mechanism of late-onset obesity in male AR null mutant (ARKO) mice. We determined that the obesity was caused by a hypercorticoid state. The negative feedback system regulating glucocorticoid production was impaired in ARKO mice. Male and female ARKO mice exhibited hypertrophic adrenal glands and glucocorticoid overproduction, presumably due to high levels of adrenal corticotropic hormone. The pituitary glands of the ARKO males had increased expression of proopiomelanocortin and decreased expression of the glucocorticoid receptor (GR). There were no overt structural abnormalities and no alteration in the distribution of cell types in the pituitaries of male ARKO mice. Additionally, there was normal production of the other hormones within the glucocorticoid feedback system in both the pituitary and hypothalamus. In a cell line derived from pituitary glands, GR expression was under the positive control of the activated AR. Thus, this study suggests that the activated AR supports the negative feedback regulation of glucocorticoid production via up-regulation of GR expression in the pituitary gland

    Phenotypes of GABA<sub>B</sub>R1-null mice.

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    <p>Plasma was collected from blood of male mice at 4 weeks old, followed by measurement of (A) leptin and (B) insulin using ELISA kits. Various tissues were dissected from male mice at 4 weeks old, followed by measurement of wet weights of (C) WAT and (D) other tissues for calculation of the percentage over body weight. (E) Mice were fed with powder diets for 1 week, followed by measurement of the accumulated amount of food intake during 1 week. Open-field tests were carried out using male mice at 4 weeks old for (F) the number of crossing and (G) the number of rearing. (H) Body temperature was measured at the rectum in mice. (I) Mice were fasted for 15 to 16 h and then injected ip with 2 g/kg glucose, followed by determination of blood glucose levels 15 to 120 min after the injection. (J) Basal blood glucose levels were measured in male mice at 4 weeks old. Values are the mean ± S.E. from different experiments shown in the figure. *P<0.05; **P<0.01, significantly different from each control value obtained in WT mice. B.W., body weight; Gb1, GABA<sub>B</sub>R1.</p
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