165 research outputs found
Depletion of CD40 on CD11c(+) cells worsens the metabolic syndrome and ameliorates hepatic inflammation during NASH
The co-stimulatory CD40-CD40L dyad plays a central role in fine-tuning immune reactions, including obesity-induced inflammation. Genetic ablation of CD40L reduced adipose tissue inflammation, while absence of CD40 resulted in aggravated metabolic dysfunction in mice. During obesity, CD40 expressing CD11c(+) dendritic cells (DC) and macrophages accumulate in adipose tissue and liver. We investigated the role of CD40(+)CD11c(+) cells in the metabolic syndrome and nonalcoholic steatohepatitis (NASH). DC-CD40-ko mice (CD40(fl/fl)CD11c(cre)) mice were subjected to obesity or NASH. Obesity and insulin resistance were induced by feeding mice a 54% high fat diet (HFD). NASH was induced by feeding mice a diet containing 40% fat, 20% fructose and 2% cholesterol. CD40(fl/fl)CD11c(cre )mice fed a HFD displayed increased weight gain, increased adipocyte size, and worsened insulin resistance. Moreover, CD40(fl/fl)CD11c(cre )mice had higher plasma and hepatic cholesterol levels and developed profound liver steatosis. Overall, regulatory T cell numbers were decreased in these mice. In NASH, absence of CD40 on CD11c(+) cells slightly decreased liver inflammation but did not affect liver lipid accumulation. Our experiments suggest that CD40 expressing CD11c(+) cells can act as a double-edged sword: CD40 expressing CD11c(+) cells contribute to liver inflammation during NASH but are protective against the metabolic syndrome via induction of regulatory T cells
Технология проведения гидравлических испытаний промысловых нефтепроводов в условиях Западной Сибири
Объектом исследования является методика и технология проведения гидравлических испытаний нефтепровода. Целью данной работы является исследование актуальной научно-технической проблемы обеспечения требуемых условий и средств для проведения гидравлических испытаний промысловых нефтепроводов. В соответствии с поставленной целью были выдвинуты следующие задачи:
1. Определить необходимую номенклатуру и объем подготовительных работ для проведения испытаний промыслового нефтепровода;
2. Исследовать основные факторы и их влияние на процесс гидравлических испытаний нефтепровода в промысловых условиях;
3. Выбор средств и методов, исключающих влияние внешних факторов на достоверность результатов испытаний.The object of study is the methodology and technology for conducting hydraulic tests of the oil pipeline. The aim of this work is to study the urgent scientific and technical problems of providing the required conditions and means for conducting hydraulic tests of field pipelines. In accordance with the goal, the following tasks were put forward:
1. To determine the necessary nomenclature and scope of preparatory work for testing the oil field pipeline;
2. Investigate the main factors and their influence on the process of hydraulic testing of the pipeline in the field;
3. The choice of tools and methods that exclude the influence of external factors on the reliability of the test results
Микрофлора природных вод источников нецентрализованного питьевого водоснабжения
Изучен микробиологический состав источников нецентрализованного водоснабжения г. Томска. Выявлено большое разнообразие и численность различных групп микроорганизмов, отрицательно влияющих на качество воды. Показана опасность использования природных вод источников нецентрализованного водоснабжения в питьевых целях без процедуры водоподготовки. The microbiological composition of the decentralized water supply sources of Tomsk city is investigated. There is revealed the large diversity and significant count of different microorganism groups that adversely affect a water quality. It is demonstrated the hazard of using of decentralized water supply sources for drinking without treatment
Standardized, systemic phenotypic analysis reveals kidney dysfunction as main alteration of Kctd1 I27N mutant mice
Background: Increased levels of blood plasma urea were used as phenotypic parameter for establishing novel mouse models for kidney diseases on the genetic background of C3H inbred mice in the phenotype-driven Munich ENU mouse mutagenesis project. The phenotypically dominant mutant line HST014 was established and further analyzed. Methods: Analysis of the causative mutation as well as the standardized, systemic phenotypic analysis of the mutant line was carried out. Results: The causative mutation was detected in the potassium channel tetramerization domain containing 1 (Kctd1) gene which leads to the amino acid exchange Kctd1 I27N thereby affecting the functional BTB domain of the protein. This line is the first mouse model harboring a Kctd1 mutation. Kctd1 I27N homozygous mutant mice die perinatally. Standardized, systemic phenotypic analysis of Kctd1 I27N heterozygous mutants was carried out in the German Mouse Clinic (GMC). Systematic morphological investigation of the external physical appearance did not detect the specific alterations that are described in KCTD1 mutant human patients affected by the scalp-ear-nipple (SEN) syndrome. The main pathological phenotype of the Kctd1 I27N heterozygous mutant mice consists of kidney dysfunction and secondary effects thereof, without gross additional primary alterations in the other phenotypic parameters analyzed. Genome-wide transcriptome profiling analysis at the age of 4 months revealed about 100 differentially expressed genes (DEGs) in kidneys of Kctd1 I27N heterozygous mutants as compared to wild-type controls. Conclusions: In summary, the main alteration of the Kctd1 I27N heterozygous mutants consists in kidney dysfunction. Additional analyses in 9–21 week-old heterozygous mutants revealed only few minor effects
Dll1 Haploinsufficiency in Adult Mice Leads to a Complex Phenotype Affecting Metabolic and Immunological Processes
BACKGROUND: The Notch signaling pathway is an evolutionary conserved signal transduction pathway involved in embryonic patterning and regulation of cell fates during development and self-renewal. Recent studies have demonstrated that this pathway is integral to a complex system of interactions, involving as well other signal transduction pathways, and implicated in distinct human diseases. Delta-like 1 (Dll1) is one of the known ligands of the Notch receptors. The role of the Notch ligands is less well understood. Loss-of-function of Dll1 leads to embryonic lethality, but reduction of Delta-like 1 protein levels has not been studied in adult stage. METHODOLOGY/PRINCIPAL FINDINGS: Here we present the haploinsufficient phenotype of Dll1 and a missense mutant Dll1 allele (Dll1(C413Y)). Haploinsufficiency leads to a complex phenotype with several biological processes altered. These alterations reveal the importance of Dll1 mainly in metabolism, energy balance and in immunology. The animals are smaller, lighter, with altered fat to lean ratio and have increased blood pressure and a slight bradycardia. The animals have reduced cholesterol and triglyceride levels in blood. At the immunological level a subtle phenotype is observed due to the effect and fine-tuning of the signaling network at the different levels of differentiation, proliferation and function of lymphocytes. Moreover, the importance of the proteolytic regulation of the Notch signaling network emphasized. CONCLUSIONS/SIGNIFICANCE: In conclusion, slight alterations in one player of Notch signaling alter the entire organism, emphasizing the fine-tuning character of this pathway in a high number of processes
Loss of the Actin Remodeler Eps8 Causes Intestinal Defects and Improved Metabolic Status in Mice
In a variety of organisms, including mammals, caloric restriction improves metabolic status and lowers the incidence of chronic-degenerative diseases, ultimately leading to increased lifespan. Here we show that knockout mice for Eps8, a regulator of actin dynamics, display reduced body weight, partial resistance to age- or diet-induced obesity, and overall improved metabolic status. Alteration in the liver gene expression profile, in behavior and metabolism point to a calorie restriction-like phenotype in Eps8 knockout mice. Additionally, and consistent with a calorie restricted metabolism, Eps8 knockout mice show increased lifespan. The metabolic alterations in Eps8 knockout mice correlated with a significant reduction in intestinal fat absorption presumably caused by a 25% reduction in intestinal microvilli length. Our findings implicate actin dynamics as a novel variable in the determination of longevity. Additionally, our observations suggest that subtle differences in energy balance can, over time, significantly affect bodyweight and metabolic status in mice
Pleiotropic effects in Eya3 knockout mice
<p>Abstract</p> <p>Background</p> <p>In <it>Drosophila</it>, mutations in the gene <it>eyes absent </it>(<it>eya</it>) lead to severe defects in eye development. The functions of its mammalian orthologs <it>Eya1-4 </it>are only partially understood and no mouse model exists for <it>Eya3</it>. Therefore, we characterized the phenotype of a new <it>Eya3 </it>knockout mouse mutant.</p> <p>Results</p> <p>Expression analysis of <it>Eya3 </it>by <it>in-situ </it>hybridizations and β-Gal-staining of <it>Eya3 </it>mutant mice revealed abundant expression of the gene throughout development, e.g. in brain, eyes, heart, somites and limbs suggesting pleiotropic effects of the mutated gene. A similar complex expression pattern was observed also in zebrafish embryos.</p> <p>The phenotype of young adult <it>Eya3 </it>mouse mutants was systematically analyzed within the German Mouse Clinic. There was no obvious defect in the eyes, ears and kidneys of <it>Eya3 </it>mutant mice. Homozygous mutants displayed decreased bone mineral content and shorter body length. In the lung, the tidal volume at rest was decreased, and electrocardiography showed increased JT- and PQ intervals as well as decreased QRS amplitude. Behavioral analysis of the mutants demonstrated a mild increase in exploratory behavior, but decreased locomotor activity and reduced muscle strength. Analysis of differential gene expression revealed 110 regulated genes in heart and brain. Using real-time PCR, we confirmed <it>Nup155 </it>being down regulated in both organs.</p> <p>Conclusion</p> <p>The loss of <it>Eya3 </it>in the mouse has no apparent effect on eye development. The wide-spread expression of <it>Eya3 </it>in mouse and zebrafish embryos is in contrast to the restricted expression pattern in <it>Xenopus </it>embryos. The loss of <it>Eya3 </it>in mice leads to a broad spectrum of minor physiological changes. Among them, the mutant mice move less than the wild-type mice and, together with the effects on respiratory, muscle and heart function, the mutation might lead to more severe effects when the mice become older. Therefore, future investigations of <it>Eya3 </it>function should focus on aging mice.</p
Исследование кинетики накопления коллоидного гептасульфида рения
SummaryInflammatory cytokines are well-recognized mediators of atherosclerosis. Depending on the pathological context, type I interferons (IFNs; IFNα and IFNβ) exert either pro- or anti-inflammatory immune functions, but their exact role in atherogenesis has not been clarified. Here, we demonstrate that IFNβ enhances macrophage-endothelial cell adhesion and promotes leukocyte attraction to atherosclerosis-prone sites in mice in a chemokine-dependent manner. Moreover, IFNβ treatment accelerates lesion formation in two different mouse models of atherosclerosis and increases macrophage accumulation in the plaques. Concomitantly, absence of endogenous type I IFN signaling in myeloid cells inhibits lesion development, protects against lesional accumulation of macrophages, and prevents necrotic core formation. Finally, we show that type I IFN signaling is upregulated in ruptured human atherosclerotic plaques. Hereby, we identify type I IFNs as proatherosclerotic cytokines that may serve as additional targets for prevention or treatment
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