Rosenwald M.,ETH Zurich |
Perdikari A.,ETH Zurich |
Rulicke T.,Institute of Laboratory Animal Science |
Wolfrum C.,ETH Zurich
Nature Cell Biology | Year: 2013
Brown adipose tissue helps to maintain body temperature in hibernators, rodents and neonatal mammals by converting lipids and glucose into heat, thereby increasing energy expenditure. In addition to classical brown adipocytes, adult rodents - like adult humans - harbour brown-like adipocytes in the predominantly white adipose tissue. The formation of these brite (brown-in-white) adipocytes is a physiological response to chronic cold and their cellular origin is under debate. We show here that cold-induced formation of brite adipocytes in mice is reversed within 5 weeks of warm adaptation, but the brite adipocytes formed by cold stimulation are not eliminated. Genetic tracing and transcriptional characterization of isolated adipocytes demonstrates that they are converted into cells with the morphology and gene expression pattern of white adipocytes. Moreover, these white-typical adipocytes can convert into brite adipocytes on additional cold stimulation. Shifting the balance of this interconversion from the white towards the brite phenotype might provide a new means of counteracting obesity by increasing energy expenditure. © 2013 Macmillan Publishers Limited. All rights reserved.
Kong Q.,Chinese Association for Laboratory Animal science CALAS |
Qin C.,Institute of Laboratory Animal Science |
Qin C.,Chinese Association for Laboratory Animal science CALAS
ILAR Journal | Year: 2010
Laboratory animal science (LAS) advances scientific understanding of the care and use of animals that play a key role in research supporting the development of biomedicine. LAS has developed quickly in China in recent decades, and this report provides an analysis of the current status of the country's LAS policies and administration. National and provincial laws, regulations, guidelines, and standards apply to quality control and licensing, quarantine and infectious disease control, breeding and husbandry, transgenic animals, staff qualifications, animal welfare, and imports, exports, and transportation. Regulation and oversight of lab animal use are the responsibility of the national Ministry of Science and Technology, provincial departments of science and technology, and institutional animal care and use committees. We begin with an explanation of the rationale behind this paper and a brief history of policy-related activities and achievements. We then present various policies, discuss their implementation, and hypothesize about future policy developments. With the improvement of policies under an integrated, multitiered administration, the use of high-quality lab animals in Chinese scientific research is increasing and many more papers describing animal experiments performed in China are being published in international journals.
Tang T.,China Agricultural University |
Zhang L.,Institute of Laboratory Animal Science |
Gao R.,Institute of Laboratory Animal Science |
Dai Y.,China Agricultural University |
And 2 more authors.
Applied Microbiology and Biotechnology | Year: 2012
Bacterial magnetic particles (BMPs) are of interest as potential carriers of bioactive macromolecules, drugs, or liposomes. In this study, a high-pressure homogenizer was used to disrupt Magnetospirillum gryphiswaldense strain MSR-1 cells, and BMPs were purified. BMPs were labeled with fluorescence reagent 1,1'-dioctadecyl-3,3,3',3'tetramethylindocarbocianin perchlorate (DiI) and injected into the tail vein of BALB/c nude mice. Distribution of fluorescence signals of DiI-BMPs in vivo was examined using a whole-body fluorescence imaging system. The result showed that fluorescence signals were detected in liver, stomach, intestine, lungs, and spleen. However, transmission electron microscopy of ultrathin sections indicated that BMPs were mainly present in liver and lungs, but not in the other organs. BMPs could be useful as carriers for targeted drug therapy of diseases of the liver or lung. © Springer-Verlag 2012.
Jorns A.,Hannover Medical School |
Rath K.J.,Hannover Medical School |
Terbish T.,Hannover Medical School |
Arndt T.,Hannover Medical School |
And 4 more authors.
Endocrinology | Year: 2010
The prevention of diabetes by the immunomodulatory agent FTY720 (fingolimod) was studied in the LEW.1AR1-iddm (IDDM) rat, an animal model of human type 1 diabetes. Immune cell subtypes and cytokine profiles in pancreatic islets, secondary lymphoid tissue, and serum were analyzed for signs of immune cell activation. Animals were treated with FTY720 (1 mg/kg body weight) for 40 d starting on d 50 of life. Changes in gene and protein expression of cytokines, CD8 markers, monocyte chemoattractant protein-1, inducible NO synthase, and caspase 3 were evaluated. Treatment with FTY720 prevented diabetes manifestation and islet infiltration around d 60 of life, the usual time of spontaneous diabetes development. On d 120, 30 d after the end of FTY720 therapy, diabetes prevention persisted. However, six of 12 treated animals showed increased gene expression of IL-1β, TNF-α, and CD8 markers in pancreas-draining lymph nodes, indicating immune cell activation. In parallel, serum concentrations of these proinflammatory cytokines were increased. These six animals also showed macrophage infiltration without proinflammatory cytokine expression in a small minority (2-3%) of islets. Interestingly, regulatory T lymphocytes were significantly increased in the efferent vessels of the pancreas-draining lymph nodes only in animals without signs of immune cell activation but not in the rats with immune cell activation. This provides an indication for a lack of protective capacity in the animals with activated immune cells. Thus, FTY720 treatment prevented the manifestation of diabetes by promoting the retention of activated immune cells in the lymph nodes, thereby avoiding islet infiltration and β-cell destruction by proinflammatory cytokines. Copyright © 2010 by The Endocrine Society.
Memo M.,Imperial College London |
Leung M.-C.,Imperial College London |
Ward D.G.,University of Birmingham |
Dos Remedios C.,University of Sydney |
And 7 more authors.
Cardiovascular Research | Year: 2013
AimsThe pure form of familial dilated cardiomyopathy (DCM) is mainly caused by mutations in genes encoding sarcomeric proteins. Previous measurements using recombinant proteins suggested that DCM mutations in thin filament proteins decreased myofibrillar Ca2+ sensitivity, but exceptions were reported. We re-investigated the molecular mechanism of familial DCM using native proteins.Methods and resultsWe used the quantitative in vitro motility assay and native troponin and tropomyosin to study DCM mutations in troponin I, troponin T, and -tropomyosin. Four mutations reduced myofilament Ca2+ sensitivity, but one mutation (TPM1 E54K) did not alter Ca2+ sensitivity and another (TPM1 D230N) increased Ca2+ sensitivity. In thin filaments from normal human and mouse heart, protein kinase A (PKA) phosphorylation of troponin I caused a two- to three-fold decrease in myofibrillar Ca2+ sensitivity. However, Ca2+ sensitivity did not change with the level of troponin I phosphorylation in any of the DCM-mutant containing thin filaments (E40K, E54K, and D230N in -tropomyosin; R141W and ΔK210 in cardiac troponin T; K36Q in cardiac troponin I; G159D in cardiac troponin C, and E361G in cardiac -actin). This 'uncoupling' was observed with native mutant protein from human and mouse heart and with recombinant mutant protein expressed in baculovirus/Sf9 systems. Uncoupling was independent of the fraction of mutated protein present above 0.55.ConclusionWe conclude that DCM-causing mutations in thin filament proteins abolish the relationship between myofilament Ca2+ sensitivity and troponin I phosphorylation by PKA. We propose that this blunts the response to β-adrenergic stimulation and could be the cause of DCM in the long term. © 2013 Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2013.