Su M.,Fuwai Hospital |
Wang J.,Fuwai Hospital |
Wang C.,Fuwai Hospital |
Wang X.,Fuwai Hospital |
And 8 more authors.
Cell Death and Differentiation | Year: 2015
MicroRNAs have emerged as crucial regulators of cardiac homeostasis and remodeling in various cardiovascular diseases. We previously demonstrated that miR-221 regulated cardiac hypertrophy in vitro. In the present study, we demonstrated that the cardiac-specific overexpression of miR-221 in mice evoked cardiac dysfunction and heart failure. The lipidated form of microtubule-associated protein 1 light chain 3 was significantly decreased and sequestosome 1 was accumulated in cardiac tissues of transgenic (TG) mice, indicating that autophagy was impaired. Overexpression of miR-221 in vitro reduced autophagic flux through inhibiting autophagic vesicle formation. Furthermore, mammalian target of rapamycin (mTOR) was activated by miR-221, both in vivo and in vitro. The inactivation of mTOR abolished the miR-221-induced inhibition of autophagy and cardiac remodeling. Our previous study has demonstrated that cyclin-dependent kinase (CDK) inhibitor p27 was a direct target of miR-221 in cardiomyocytes. Consistently, the expression of p27 was markedly suppressed in the myocardia of TG mice. Knockdown of p27 by siRNAs was sufficient to mimic the effects of miR-221 overexpression on mTOR activation and autophagy inhibition, whereas overexpression of p27 rescued miR-221-induced autophagic flux impairment. Inhibition of CDK2 restored the impaired autophagic flux and rescued the cardiac remodeling induced by either p27 knockdown or miR-221 overexpression. These findings reveal that miR-221 is an important regulator of autophagy balance and cardiac remodeling by modulating the p27/CDK2/mTOR axis, and implicate miR-221 as a therapeutic target in heart failure. © 2015 Macmillan Publishers Limited All rights reserved.
Bomsel M.,French National Center for Scientific Research |
Bomsel M.,French Institute of Health and Medical Research |
Bomsel M.,University of Paris Descartes |
Tudor D.,French National Center for Scientific Research |
And 26 more authors.
Immunity | Year: 2011
Human immunodeficiency virus (HIV)-1 is mainly transmitted mucosally during sexual intercourse. We therefore evaluated the protective efficacy of a vaccine active at mucosal sites. Macaca mulatta monkeys were immunized via both the intramuscular and intranasal routes with an HIV-1 vaccine made of gp41-subunit antigens grafted on virosomes, a safe delivery carrier approved in humans with self-adjuvant properties. Six months after 13 vaginal challenges with simian-HIV (SHIV)-SF162P3, four out of five vaccinated animals remained virus-negative, and the fifth was only transiently infected. None of the five animals seroconverted to p27. gag-SIV. In contrast, all 6 placebo-vaccinated animals became infected and seroconverted. All protected animals showed gp41-specific vaginal IgAs with HIV-1 transcytosis-blocking properties and vaginal IgGs with neutralizing and/or antibody-dependent cellular-cytotoxicity activities. In contrast, plasma IgGs totally lacked virus-neutralizing activity. The protection observed challenges the paradigm whereby circulating antiviral antibodies are required for protection against HIV-1 infection and may serve in designing a human vaccine against HIV-1-AIDS. © 2011 Elsevier Inc.
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.
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.
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.
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.
Yang Y.,Institute of Laboratory Animal Science |
Xiu J.,Institute of Laboratory Animal Science |
Zhang X.,Institute of Laboratory Animal Science |
Zhang L.,Institute of Laboratory Animal Science |
And 3 more authors.
Molecules | Year: 2012
Human enterovirus 71, a member of the Picornaviridae family, is one of the major causative agent of hand, foot and mouth disease in children less than six years old. This illness has caused mortalities in large-scale outbreaks in the Asia-Pacific region in recent years. No vaccine or antiviral therapy is available. In this study, antiviral effect of matrine against enterovirus 71 were evaluated in vitro and in vivo. Matrine could suppress the viral RNA copy number on rhabdomyosarcoma cells. Moreover, matrine treatment of mice challenged with a lethal dose of enterovirus 71 reduced the mortality and relieved clinical symptoms. The results showed that matrine may represent a potential therapeutic agent for enterovirus 71 infection. © 2012 by the authors.
Lu D.,Institute of Laboratory Animal Science |
Ma Y.,Institute of Laboratory Animal Science |
Zhang W.,Institute of Laboratory Animal Science |
Bao D.,Institute of Laboratory Animal Science |
And 5 more authors.
Hypertension | Year: 2012
Cytochrome P450 2E1 (CYP2E1) is a cytochrome P450 enzyme that catalyzes the metabolism of toxic substrates. CYP2E1 is upregulated in heart disease, including the dilated cardiomyopathy (DCM) mouse model. Here, knockdown of CYP2E1 significantly ameliorated the dilated left ventricle, thin wall, and dysfunctional contraction in the cTnTR141W and adriamycin-induced DCM mouse models. Interstitial fibrosis, poorly organized myofibrils, and swollen mitochondria with loss of cristae were improved in the myocardium of α-myosin heavy chain (MHC)-cTnTR141W XCYP2E1-silence double-transgenic mice when compared with the cTnTR141W transgenic mice. Oxidative stress, the activation of caspase 3 and caspase 9, the release of cytochrome c, and the apoptosis in the myocardium were significantly decreased in double-transgenic mice compared with the cTnTR141W transgenic mice. In summary, the expression of CYP2E1 is upregulated in heart disease and might be induced by hypoxemia in cardiomyopathy. The overexpression of CYP2E1 can enhance the metabolism of endogenous ketones to meet the energy demand of the heart in certain disease states, but the overexpression of CYP2E1 can also increase oxidative stress and apoptosis in the DCM heart. Knockdown or downregulation of CYP2E1 might be a therapeutic strategy to control the development of DCM after mutations of cTnTR141W or other factors, because DCM is the third most common cause of heart failure and the most frequent cause of heart transplantation. © 2012 American Heart Association, Inc.
Yang Y.,Institute of Laboratory Animal Science |
Zhang L.,Institute of Laboratory Animal Science |
Fan X.,Institute of Laboratory Animal Science |
Qin C.,Institute of Laboratory Animal Science |
Liu J.,Institute of Laboratory Animal Science
Bioorganic and Medicinal Chemistry Letters | Year: 2012
Human enterovirus 71 infection causes hand, foot and mouth disease in children under 6 years of age and has caused mortalities in large-scale outbreaks in the Asia-Pacific region. No effective vaccine or antiviral drugs currently exist against enterovirus 71 in the clinic. In this study, we investigated the antiviral effect of geraniin on enterovirus 71 both in vitro and in vivo. The results showed that geraniin effectively inhibited virus replication in rhabdomyosarcoma cells with an IC 50 of 10 μg/ml. Moreover, geraniin treatment of mice that were challenged with a lethal dose of enterovirus 71 resulted in a reduction of mortality, relieved clinical symptoms, and inhibited virus replication in muscle tissues. The results suggest that geraniin may be used as a potential drug for anti-enterovirus 71. © 2011 Elsevier Ltd. 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.