16 research outputs found

    UCP1-dependent and UCP1-independent metabolic changes induced by acute cold exposure in brown adipose tissue of mice

    Get PDF
    Background: Brown adipose tissue (BAT) is a site of metabolic thermogenesis mediated by mitochondrial uncoupling protein 1 (UCP1) and represents a target for a therapeutic intervention in obesity. Cold exposure activates UCP1-mediated thermogenesis in BAT and causes drastic changes in glucose, lipid, and amino acid metabolism; however, the relationship between these metabolic changes and UCP1-mediated thermogenesis is not fully understood. Methods: We conducted metabolomic and GeneChip array analyses of BAT after 4-h exposure to cold temperature (10 °C) in wild-type (WT) and UCP1-KO mice. Results: Cold exposure largely increased metabolites of the glycolysis pathway and lactic acid levels in WT, but not in UCP1-KO, mice, indicating that aerobic glycolysis is enhanced as a consequence of UCP1-mediated thermogenesis. GeneChip array analysis of BAT revealed that there were 2865 genes upregulated by cold exposure in WT mice, and 838 of these were upregulated and 74 were downregulated in UCP1-KO mice. Pathway analysis revealed the enrichment of genes involved in fatty acid (FA) ÎČ oxidation and triglyceride (TG) synthesis in both WT and UCP1-KO mice, suggesting that these metabolic pathways were enhanced by cold exposure independently of UCP1-mediated thermogenesis. FA and cholesterol biosynthesis pathways were enhanced only in UCP1-KO mice. Cold exposure also significantly increased the BAT content of proline, tryptophan, and phenylalanine amino acids in both WT and UCP1-KO mice. In WT mice, cold exposure significantly increased glutamine content and enhanced the expression of genes related to glutamine metabolism. Surprisingly, aspartate was almost completely depleted after cold exposure in UCP1-KO mice. Gene expression analysis suggested that aspartate was actively utilized after cold exposure both in WT and UCP1-KO mice, but it was replenished from intracellular N-acetyl-aspartate in WT mice. Conclusions: These results revealed that cold exposure induces UCP1-mediated thermogenesis-dependent glucose utilization and UCP1-independent active lipid metabolism in BAT. In addition, cold exposure largely affects amino acid metabolism in BAT, especially UCP1-dependently enhances glutamine utilization. These results contribute a comprehensive understanding of UCP1-mediated thermogenesis-dependent and thermogenesis-independent metabolism in BAT

    DNA Methylation Is Dispensable for the Growth and Survival of the Extraembryonic Lineages

    Get PDF
    SummaryDNA methylation regulates development and many epigenetic processes in mammals [1], and it is required for somatic cell growth and survival [2, 3]. In contrast, embryonic stem (ES) cells can self-renew without DNA methylation [4–6]. It remains unclear whether any lineage-committed cells can survive without DNA-methylation machineries. Unlike in somatic cells, DNA methylation is dispensable for imprinting and X-inactivation in the extraembryonic lineages [7–12]. In ES cells, DNA methylation prevents differentiation into the trophectodermal fate [13]. Here, we created triple-knockout (TKO) mouse embryos deficient for the active DNA methyltransferases Dnmt1, Dnmt3a, and Dnmt3b (TKO) by nuclear transfer (NT), and we examined their development. In chimeric TKO-NT and WT embryos, few TKO cells were found in the embryo proper, but they contributed to extraembryonic tissues. TKO ES cells showed increasing cell death during their differentiation into epiblast lineages, but not during differentiation into extraembryonic lineages. Furthermore, we successfully established trophoblastic stem cells (ntTS cells) from TKO-NT blastocysts. These TKO ntTS cells could self-renew, and they retained the fundamental gene expression patterns of stem cells. Our findings indicated that extraembryonic-lineage cells can survive and proliferate in the absence of DNA methyltransferases and that a cell's response to the stress of epigenomic damage is cell type dependent

    Postoperative assessment after AVR and TAVI

    Get PDF
    Background and aims : Severe aortic stenosis (AS) has been normally treated with surgical aortic valve replacement (AVR) whereas recently, transcatheter aortic valve implantation (TAVI) has been introduced as a minimally invasive operation for patients with high surgical risk and frailty. In this study, we have evaluated postoperative physical function and nutrition intake in the patients following AVR and TAVI. Methods : This prospective observational study involved 9 patients with surgical aortic valve replacement (AVR) and 7 patients with transcatheter aortic valve implantation (TAVI). Body composition was measured one day prior surgery, postoperative day (POD) 1, POD 3, POD 5 and POD 7. Hand grip strength, calf circumference and gait speed were measured one day before surgery and on the day of discharge. Results : Skeletal muscle was significantly decreased in AVR patients at postoperative day 3 and 7, while there was no change in TAVI patients. Patients with TAVI showed higher dietary intake after surgery compared to patients with AVR, and they maintained hand grip strength and calf circumference at discharge. Conclusions : In elderly patients with AS, TAVI can improve post-operative recovery maintaining nutritional status and physical function even

    Effects of colour narrative in community-dwelling older adults: A mixed methods study

    Get PDF
    Background Based on occupational storytelling/story-making, this study developed Colour Narrative, a program to promote the health and well-being of community-dwelling older adults. Objectives To conduct a pilot study to implement Colour Narrative in a heavy snowfall area of Japan and verify the participants' experiences in the program and its effectiveness. Material and methods An advanced mixed methods design was used. The participants were 22 members of a community-based social group for older adults. Quantitative measurements of life functions and health-related quality of life (HRQOL) were conducted before and after the intervention. Qualitative data were collected from focus group interviews regarding the participants' experiences during the intervention process. Lastly, both datasets were integrated. Results The harsh living conditions due to heavy snowfall reduced the participants' overall activity. In this environment, Colour Narrative encouraged them to control their lives more in their own ways and enhanced their HRQOL. The core of their experiences was 'negotiating occupations'. This negotiation was a highly intellectual task that significantly improved their cognitive function. Conclusions The structure and content of Colour Narrative were found to be useful and feasible for community-dwelling older adults. Significance Colour Narrative offers a new occupation-based intervention strategy for preventive occupational therapy

    Diet-Induced Up-Regulation of Gene Expression in Adipocytes Without Changes in DNA Methylation

    Get PDF
    The expansion of white adipose tissue (WAT) mass during the development ofobesity is mediated in part through an increase in adipocyte size. Although geneexpression profiles associated with adipogenesis in vitro and the development of obesityin vivo have been characterized by DNA microarray analysis, the role of chromatin andchromatin-modifying proteins in the regulation of gene expression related to adipocytehypertrophy has remained unclear. We have now shown that maintenance of C57BL/6Jmice on a high-fat diet for 16 weeks resulted in marked up-regulation of the expressionof leptin, Mest (mesoderm specific transcript; also known as paternally expressed gene1, or Peg1), and sFRP5 (secreted frizzled-related protein 5) genes in WAT.Furthermore, the demethylating agent 5-aza-2â€Č-deoxycytidine increased the amount ofMest/Peg1 mRNA, but not that of leptin or sFRP5 mRNAs, in mouse 3T3-L1adipocytes. However, analysis by matrix-assisted laser desorption ionizationtime-of-flight (MALDI-TOF) mass spectrometry revealed that maintenance of mice ona high-fat diet for various times did not affect the level of methylation at specific CpGsites in the promoter regions of leptin, Mest/Peg1, and sFRP5 genes in WAT. Ourresults indicate that the diet-induced up-regulation of leptin, Mest/Peg1, and sFRP5gene expression in WAT during the development of obesity in mice is not mediateddirectly by changes in DNA methylation

    Cell-cycle arrest in mature adipocytes impairs BAT development but not WAT browning, and reduces adaptive thermogenesis in mice

    Get PDF
    We previously reported brown adipocytes can proliferate even after differentiation. To test the involvement of mature adipocyte proliferation in cell number control in fat tissue, we generated transgenic (Tg) mice over-expressing cell-cycle inhibitory protein p27 specifically in adipocytes, using the aP2 promoter. While there was no apparent difference in white adipose tissue (WAT) between wild-type (WT) and Tg mice, the amount of brown adipose tissue (BAT) was much smaller in Tg mice. Although BAT showed a normal cellular morphology, Tg mice had lower content of uncoupling protein 1 (UCP1) as a whole, and attenuated cold exposure-or beta 3-adrenergic receptor (AR) agonist-induced thermogenesis, with a decrease in the number of mature brown adipocytes expressing proliferation markers. An agonist for the beta 3-AR failed to increase the number of proliferating brown adipocytes, UCP1 content in BAT, and oxygen consumption in Tg mice, although the induction and the function of beige adipocytes in inguinal WAT from Tg mice were similar to WT mice. These results show that brown adipocyte proliferation significantly contributes to BAT development and adaptive thermogenesis in mice, but not to induction of beige adipocytes

    UCP1-dependent and UCP1-independent metabolic changes induced by acute cold exposure in brown adipose tissue of mice

    No full text
    Background: Brown adipose tissue (BAT) is a site of metabolic thermogenesis mediated by mitochondrial uncoupling protein 1 (UCP1) and represents a target for a therapeutic intervention in obesity. Cold exposure ac-tivates UCP1-mediated thermogenesis in BAT and causes drastic changes in glucose, lipid, and amino acid metabolism; however, the relationship between these metabolic changes and UCP1-mediated thermogenesis is not fully understood. Methods: We conducted metabolomic and GeneChip array analyses of BAT after 4-h exposure to cold temperature (10 degrees C) in wild-type (WT) and UCP1-KO mice. Results: Cold exposure largely increased metabolites of the glycolysis pathway and lactic acid levels in WT, but not in UCP1-KO, mice, indicating that aerobic glycolysis is enhanced as a consequence of UCP1-mediated thermogenesis. GeneChip array analysis of BAT revealed that there were 2865 genes upregulated by cold exposure in WT mice, and 838 of these were upregulated and 74 were downregulated in UCP1-KO mice. Pathway analysis revealed the enrichment of genes involved in fatty acid (FA) beta oxidation and triglyceride (TG) synthesis in both WT and UCP1-KO mice, suggesting that these metabolic pathways were enhanced by cold exposure independently of UCP1-mediated thermogenesis. FA and cholesterol biosynthesis pathways were enhanced only in UCP1-KO mice. Cold exposure also significantly increased the BAT content of proline, tryptophan, and phenylalanine amino acids in both WT and UCP1-KO mice. In WT mice, cold exposure significantly increased glutamine content and enhanced the expression of genes related to glutamine metabolism. Surprisingly, aspartate was almost completely depleted after cold exposure in UCP1-KO mice. Gene expression analysis suggested that aspartate was actively utilized after cold exposure both in WT and UCP1-KO mice, but it was replenished from intracellular N-acetyl-aspartate in WT mice. Conclusions: These results revealed that cold exposure induces UCP1-mediated thermogenesis-dependent glucose utilization and UCP1-independent active lipid metabolism in BAT. In addition, cold exposure largely affects amino acid metabolism in BAT, especially UCP1-dependently enhances glutamine utilization. These results contribute a comprehensive understanding of UCP1-mediated thermogenesis-dependent and thermogenesisindependent metabolism in BAT. (c) 2020 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

    Immunolocalization of choline acetyltransferase of common type in the central brain mass of Octopus vulgaris.

    Get PDF
    Acetylcholine, the first neurotransmitter to be identified in the vertebrate frog, is widely distributed among the animal kingdom. The presence of a large amount of acetylcholine in the nervous system of cephalopods is well known from several biochemical and physiological studies. However, little is known about the precise distribution of cholinergic structures due to a lack of a suitable histochemical technique for detecting acetylcholine. The most reliable method to visualize the cholinergic neurons is the immunohistochemical localization of the enzyme choline acetyltransferase, the synthetic enzyme of acetylcholine. Following our previous study on the distribution patterns of cholinergic neurons in the Octopus vulgaris visual system, using a novel antibody that recognizes choline acetyltransferase of the common type (cChAT), now we extend our investigation on the octopus central brain mass. When applied on sections of octopus central ganglia, immunoreactivity for cChAT was detected in cell bodies of all central brain mass lobes with the notable exception of the subfrontal and subvertical lobes. Positive varicosed nerves fibers where observed in the neuropil of all central brain mass lobes
    corecore