20 research outputs found

    Akv murine leukemia virus enhances bone tumorigenesis in hMT-c-fos-LTR transgenic mice

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    AbstracthMt-c-fos-LTR transgenic mice (U. Rüther, D. Komitowski, F. R. Schubert, and E. F. Wagner. Oncogene 4, 861–865, 1989) developed bone sarcomas in 20% (3/15) of females at 448 ± 25 days and in 8% (1/12) of males at 523 days. After infection of newborns with Akv, an infectious retrovirus derived from the ecotropic provirus of the AKR mouse, 69% (20/28) of female animals and 83% (24/29) of males developed malignant fibrous-osseous tumors. The tumors in infected transgenics developed with higher frequency and a 200-days shorter mean tumor latency period. The hMt-c-fos-LTR transgene was expressed in all the fibrous-osseous tumors. They also showed newly integrated Akv proviruses, but in most tumors Akv was detected and expressed in only a small number of the tumor cells. Wild-type C3H mice infected with Akv developed benign osteomas with an incidence of 33% and a latency period of 474 days. The data indicate that Akv exerts distinct pathogenic effects on the skeleton. In hMt-c-fos-LTR transgenic mice, predisposed to bone sarcomagenesis, Akv acts synergistically with the fos transgene, resulting in the development of fibrous-osseous tumors

    Occurrence of birefringent retinal inclusions in cynomolgus monkeys after high doses of canthaxanthin

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    urpose. To reproduce and investigate in a primate animal model the phenomenon of the red carotenoid canthaxanthin (/?,/5-carotene-4'4'-dione) to induce crystal-like retinal deposits as they have been observed in the ocular fundus of humans after high canthaxanthin intake (i.e., more than 30 mg/day). Methods. Groups of four cynomolgus monkeys (Macaco, fascicularis) per gender and dose were administered 5.4, 16.2, or 48.6 mg candiaxanthin/kg body weight daily by oral gavage for 2.5 years. Eight control animals received placebo. In vivo ophthalmoscopy was performed at intervals of 3 months along with electroretinography after 12 and 24 months and retinal biomicroscopy just before the monkeys were killed. Retinal wholemounts or frozen sections were investigated postmortem by polarization, bright field, and differential interference contrast microscopy. Retinal and preterminal plasma canthaxanthin concentrations were determined by high-performance liquid chromatography (HPLC). Results. By ophthalmoscopy and retinal biomicroscopy in vivo, no crystals or other lightreflecting particles were observed in the central paramacular retina. However, postmortem polarization microscopy of all 24 canthaxanthin-treated animals showed a circular zone in the peripheral retina containing birefringent, polymorphous red, orange, or white inclusions. The density of these inclusions was diminished within 1 to 8 mm posterior to the ora serrata. These inclusions were located mainly in the inner retinal layers, that is, the nerve fiber layer and ganglion cell layer, inner plexiform layer, and inner nuclear layer. Twelve of the 24 canthaxanthin-treated animals showed yellow, golden birefringent inclusions in die macula. Retinas of placebo-treated monkeys were free of birefringent, crystal-like inclusions. The HPLC confirmed the presence of all-trans canthaxanthin, and 4-OH-echinenone and isozeaxanthin as well, in the retinas of all can thaxan dim-treated animals. Neither electroretinography nor histopathology indicated any adverse effects of the canthaxanthin-induced retinal inclusions seen in this study. Conclusions. A high intake of canthaxanthin for 2.5 years led to the deposition of crystal-like birefringent inclusions in the inner layers of the peripheral retina and, to some extent, the central retina of cynomolgus monkeys. The presence of these deposits did not interfere with morphology nor with retinal function. Invest Ophthalmol Vis Sci. 1997;38:741-752. A he carotenoid canthaxanthin (/?,/3-carotene-4'4'-dione) is synthesized in nature by the mushroom Cantharellus cinnabarinus. It also occurs in a variety of other plants and animals (e.g., in algae, Crustacea, birds, o

    Monoamine reuptake inhibition and mood-enhancing potential of a specified oregano extract

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    A healthy, balanced diet is essential for both physical and mental well-being. Such a diet must include an adequate intake of micronutrients, essential fatty acids, amino acids and antioxidants. The monoamine neurotransmitters, serotonin, dopamine and noradrenaline, are derived from dietary amino acids and are involved in the modulation of mood, anxiety, cognition, sleep regulation and appetite. The capacity of nutritional interventions to elevate brain monoamine concentrations and, as a consequence, with the potential for mood enhancement, has not been extensively evaluated. The present study investigated an extract from oregano leaves, with a specified range of active constituents, identified via an unbiased, high-throughput screening programme. The oregano extract was demonstrated to inhibit the reuptake and degradation of the monoamine neurotransmitters in a dose-dependent manner, and microdialysis experiments in rats revealed an elevation of extracellular serotonin levels in the brain. Furthermore, following administration of oregano extract, behavioural responses were observed in mice that parallel the beneficial effects exhibited by monoamine-enhancing compounds when used in human subjects. In conclusion, these data show that an extract prepared from leaves of oregano, a major constituent of the Mediterranean diet, is brain-active, with moderate triple reuptake inhibitory activity, and exhibits positive behavioural effects in animal models. We postulate that such an extract may be effective in enhancing mental well-being in human

    Dietary constituents reduce lipid accumulation in murine C3H10 T1/2 adipocytes: A novel fluorescent method to quantify fat droplets

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    Abstract Background Adipocyte volume (fat accumulation) and cell number (adipogenesis) is increased in obese individuals. Our objective was the identification of dietary constituents with inhibitory effects on triglyceride formation during adipogenesis. Therefore an in vitro adipose cell assay in murine C3H10 T1/2 cells was developed, which enabled rapid quantification of intracellular fat droplet accumulation during adipocyte differentiation. Results were corroborated by expression levels of several specific adipogenic and lipogenic genes which are known to regulate triglyceride accumulation. Methods C3H10 T1/2 adipocyte differentiation was conducted with rosiglitazone in the presence of test compounds for 7 days. Accumulation of intracellular lipid droplets was measured using the Cellomics® ArrayScan® VTI HCS reader and SpotDetector® BioApplication from ThermoFisher. Fluorescent images were automatically acquired and analysed employing the fluorescent dyes BODIPY® 493/503 and Hoechst 33342, for staining neutral lipids and localisation of nuclei, respectively. The expression levels of adipogenic and lipogenic genes, such as PPARα and PPARγ, C/EBPα, aP2, adiponectin, LPL and HSL, CPT-1β, ACC1, Glut4 and FAS, were determined by quantitative RT-PCR. Dietary ingredients including PUFAs, carotenoids, polyphenols and catechins were tested for their effect on lipid accumulation. Results The ω-3 PUFAs docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), the carotenoid β-carotene and hydroxytyrosol exhibited the strongest inhibitory effects on the rosiglitazone-stimulated lipid formation. (all-E)-lycopene and epigallocatechin gallate (EGCG) showed a moderate inhibition, whereas resveratrol did not reduce fat droplet formation. Additionally, it was demonstrated that adipogenic and lipogenic gene expression was attenuated. DHA, β-carotene and hydroxytyrosol inhibited the gene expression of PPARγ, C/EBPα, aP2 and CPT-1β. Conclusion This in vitro assay in differentiating adipocytes enables automated detection and quantification of changes in lipid droplet number, size and intensity. The observed inhibitory effects of identified dietary constituents such as ω-3 PUFAs and β-carotene correlate with the modulation of genes involved in adipocyte differentiation.</p

    Combinations of bio-active dietary constituents affect human white adipocyte function in-vitro

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    BACKGROUND: Specific bio-active dietary compounds modulate numerous metabolic processes in adipose tissue (AT), including pre-adipocyte proliferation and differentiation. AT dysfunction, rather than an increased fat mass per se, is strongly associated with the development of insulin resistance and is characterized by impaired adipogenesis, hypertrophic adipocytes, inflammation, and impairments in substrate metabolism. A better understanding of mechanisms underlying AT dysfunction may provide new strategies for the treatment of obesity-associated metabolic diseases. Here we evaluated the role of (all-E)-lycopene (Lyc), eicosapentaenoic acid (EPA) or trans-resveratrol (Res) and combinations thereof on human white adipocyte function. METHODS: In-vitro differentiating human pre-adipocytes were treated with EPA, Lyc and Res or their combinations for 14 days. The effects on intracellular lipid droplet (LD) accumulation, secreted anti- and pro-inflammatory cyto-/adipokines (e.g. adiponectin, IL-6, IL-8/CXCL-8 and MCP-1/CCL2) and on gene expression of markers of adipocyte differentiation and substrate metabolism (e.g. PPAR-gamma, C/EBP-alpha, GLUT-4, FAS, ATGL, HSL, and PLIN-1) were measured by fluorescent microscopy (Cellomics™), multi-parametric LiquiChip® technology and quantitative RT-PCR, respectively. RESULTS: Treatment of differentiating adipocytes for 14 days with the combination of Lyc/Res and EPA/Res resulted in significantly inhibited LD formation (~ -25 and -20%, respectively) compared to the effects of the single compounds. These morphological changes were accompanied by increased mRNA levels of the adipogenic marker PPAR-gamma and the lipase ATGL and by decreased expression levels of lipogenic markers (LPL, FAS, GLUT-4) and the LD-covering protein PLIN-1. In addition, a blunted adipocyte secretion of pro-inflammatory cytokines (IL-6 and MCP-1) and adiponectin was observed following treatment with these compounds. CONCLUSION: The combination of the dietary bio-actives Lyc and EPA with Res might influence adipocyte function by affecting the balance between adipogenic, lipogenic and lipolytic gene expression, resulting in a reduced LD storage and a less inflammatory secretion profile. Taken together, our results indicate that combinations of dietary compounds may be beneficial for the prevention and treatment of metabolic disorders via effects on human white adipocyte function. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12986-016-0143-5) contains supplementary material, which is available to authorized users
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