59 research outputs found

    The Bax/Bcl-2 Ratio Determines the Susceptibility of Human Melanoma Cells to CD95/Fas-Mediated Apoptosis

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    Defective cytochrome c release and the resulting loss of caspase-3 activation was recently shown to be essential for the susceptibility of human melanoma cells to CD95/Fas-induced apoptosis. Cytochrome c release from mitochondria is regulated by the relative amounts of apoptosis-promoting and apoptosis-inhibiting Bcl-2 proteins in the outer membrane of these organelles. The assignment of Bax/Bcl-2 ratios by quantitative Western blotting in 11 melanoma cell populations revealed a relation to the susceptibility to CD95-mediated apoptosis. We could show that a low Bax/Bcl-2 ratio was characteristic for resistant cells and a high Bax/Bcl-2 ratio was characteristic for sensitive cells. Low Bax expression was not a consequence of mutations in the p53 coding sequence. The Bax/Bcl-2 ratio was also in clear correlation with sensitivity to another cell death inducer, N-acetylsphingosine. Furthermore, Bcl-2 overexpression abolished apoptosis triggered by both apoptotic stimuli, confirming the critical role of the Bax/Bcl-2 ratio as a rheostat that determines the susceptibility to apoptosis in melanoma cells by regulating mitochondrial function. Interestingly, some chemotherapeutics lead to the activation of death pathways by CD95L upregulation, ceramide generation, direct activation of upstream caspases, or upregulation of proapoptotic genes. Taken together, these signals enter the apoptotic pathway upstream of mitochondria, resulting in activation of this central checkpoint. We therefore assumed that apoptosis deficiency of malignant melanoma can be circumvented by drugs directly influencing mitochondrial functions. For this purpose we used betulinic acid, a cytotoxic agent selective for melanoma, straightly perturbing mitochondrial functions. In fact, betulinic acid induced mitochondrial cytochrome c release and DNA fragmentation in both CD95-resistant and CD95-sensitive melanoma cell populations, independent of the Bax/Bcl-2 ratio

    Selective Induction of Apoptosis in Melanoma Cells by Tyrosinase Promoter-Controlled CD95 Ligand Overexpression

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    Induction of apoptosis has been demonstrated previously by overexpression of CD95 ligand (CD95L) in cultured human melanoma cells. For in vivo approaches based on CD95L, however, targeted expression is a prerequisite and tyrosinase promoters have been considered for selection. Luciferase reporter gene assays performed for a representative panel of melanoma cell lines characterized by strong (SK-Mel-19), moderate (SK-Mel-13, MeWo), weak (A-375), and missing expression (M-5) of endogenous tyrosinase revealed high tyrosinase promoter activities in SK-Mel-19, SK-Mel-13, and MeWo, but only weak activities in A-375 and M-5 as well as in non-melanoma cell lines. After transfection of a CMV promoter CD95L expression construct, melanoma cells were found highly sensitive, as compared with non-melanoma cells. By applying a tyrosinase promoter CD95L construct, apoptosis was selectively induced in SK-Mel-19, SK-Mel-13, MeWo as well as in A-375, which was characterized by high CD95 surface expression and high sensitivity to agonistic CD95 activation. M5 and non-melanoma cell lines remained uninfluenced. Also, resistance to agonistic CD95 activation seen in MeWo characterized by weak CD95 surface expression was overcome by overexpression of CD95L. Our investigations provide evidence that tyrosinase promoter CD95L constructs may be of value for selective induction of apoptosis in therapeutic strategies for melanoma

    An updated min-review on environmental route of the SARS-CoV-2 transmission

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    The risk of newly emerging diseases is constantly present in a world where changes occur significantly in climatic, commercial, and ecological conditions, in addition to the development of biomedical investigations in new situations. An epidemic respiratory disease instigated by a new coronavirus was initially identified in and has resulted in the current global dissemination. This viral strain and its related disease has been termed �SARS-CoV-2� and �coronavirus disease 2019� (abbreviated �COVID-19� or �2019-nCoV�), respectively, which is transmitted simply between individuals. The World Health Organization (WHO) announced the COVID-19 outburst as a pandemic on March 11, which necessitates a cooperative endeavour globally for mitigating the spread of COVID-19. The absence of previous, and minimum present-day information, particularly concerning the path of contagion have precluded the control of this disease. The present article, therefore, describes the SARS-CoV-2 paths of contagion such as drinking water, solid waste, sewer water, ambient air, and the rest of emerging likely paths. © 2020 Elsevier Inc

    Inhibition of the alternative complement activation pathway in traumatic brain injury by a monoclonal anti-factor B antibody: a randomized placebo-controlled study in mice

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    BACKGROUND: The posttraumatic response to traumatic brain injury (TBI) is characterized, in part, by activation of the innate immune response, including the complement system. We have recently shown that mice devoid of a functional alternative pathway of complement activation (factor B-/- mice) are protected from complement-mediated neuroinflammation and neuropathology after TBI. In the present study, we extrapolated this knowledge from studies in genetically engineered mice to a pharmacological approach using a monoclonal anti-factor B antibody. This neutralizing antibody represents a specific and potent inhibitor of the alternative complement pathway in mice. METHODS: A focal trauma was applied to the left hemisphere of C57BL/6 mice (n = 89) using a standardized electric weight-drop model. Animals were randomly assigned to two treatment groups: (1) Systemic injection of 1 mg monoclonal anti-factor B antibody (mAb 1379) in 400 μl phosphate-buffered saline (PBS) at 1 hour and 24 hours after trauma; (2) Systemic injection of vehicle only (400 μl PBS), as placebo control, at identical time-points after trauma. Sham-operated and untreated mice served as additional negative controls. Evaluation of neurological scores and analysis of brain tissue specimens and serum samples was performed at defined time-points for up to 1 week. Complement activation in serum was assessed by zymosan assay and by murine C5a ELISA. Brain samples were analyzed by immunohistochemistry, terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) histochemistry, and real-time RT-PCR. RESULTS: The mAb 1379 leads to a significant inhibition of alternative pathway complement activity and to significantly attenuated C5a levels in serum, as compared to head-injured placebo-treated control mice. TBI induced histomorphological signs of neuroinflammation and neuronal apoptosis in the injured brain hemisphere of placebo-treated control mice for up to 7 days. In contrast, the systemic administration of an inhibitory anti-factor B antibody led to a substantial attenuation of cerebral tissue damage and neuronal cell death. In addition, the posttraumatic administration of the mAb 1379 induced a neuroprotective pattern of intracerebral gene expression. CONCLUSION: Inhibition of the alternative complement pathway by posttraumatic administration of a neutralizing anti-factor B antibody appears to represent a new promising avenue for pharmacological attenuation of the complement-mediated neuroinflammatory response after head injury

    Investigation on possibility of enrichment some grain products (bread, cup cake and cookie) by using Spirulina Microalgae)

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    The aim of this study was to investigate the possibility of enrichment some grain products by using spirulina powder. For propose three different products (Shear bread, Cupcake and Layered Cookie) were selected. Spirulina platensis powder with 0.25, 0.5, 0.75,1 and 1.25% were added to the products ingredients. The no added products (0% spirulina) were used as control. The samples were produced in SAHAR BREAD CO. in industry method. Sensory evaluation, color and texture properties, proximate compositions, Iron, fatty acid and amino acid profile of the samples were determined. The changes of the price of the samples were also calculated. Results indicated that except in color parameter for 1.25% incorporation the spirulina in selected products had no significant (p>0.05) effects on sensory properties. Instrumental color (Hunter Lab) analysis showed that the L*,a* ,b* were decreased by increasing the percentage of spiraling powder in the products ingredients. Hardness of all three products decreased by increasing the spirulina amounts in the products ingredients. Significant (P0.05) changes of the fat and fatty acid content were observed in all treatments. Comparing the three prducts the highest increase in the price was observed in the spirulina bread samples

    Development gene data bank of cultured shrimp species in Iran

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    DNA barcode is a short, standard well known sequence of cytochrome oxidase І gene. By using this DNA sequence can be realized that each animal, plant or fungus belongs to which species. in this research, samples were collected from imported cultured shrimp Litopenaeus vannamei and and 6 Persian Gulf and Oman Sea shrimp species which classified based on traditional systematically as: Penaeus semisulcatus, Fenneropenaeus merguiensis, Metapenaeus affinis, Parapenaeopsis Stylifera and Fenneropenaeus indicus. After examination of DNA barcode sequence, molecular and bioinformatics operations of each sequence in the Consortium for the Barcode of Life (CBOL) and National Center for Biotechnology Information (NCBI), phylogenetic analysis of each sample was determined and similarity of each sample with NCBI and CBOL database was checked and the closest species to each sample were specified. According to the results different samples of L. vannamei, . banded P.semisulcatus, F. merguiensis and F. indicus have more than 97% similarity to the same species of other countries. non banded P.semisulcatus had 80.07% similarity to banded P.semisulcatus, M. affinis samples had 90.3% similarity to Metapenaeus ensis and Parap. Stylifera had 93.44% similarity to Parapenaeopsis coromandelica in the CBOL. This funding confirmed the need for further investigation and possible announcement of new species

    The production of all-female in rainbow trout (Oncorhynchus mykiss) using indirect feminization

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    The sex reversal technique in fish is widespread in many countries. The development of these techniques is desirable because rainbow trout males reach their gonad maturity earlier compared to the females. Rainbow trout alevins were treated with 17α-methyltestosterone incorporated in the diet (0.5. 1.5, 3, 6 and 10 mg/kg) for 60 days from the beginning of first feeding. Sex was determined at 180 and 680 dpf by sampling fish (n = 20) from each group and examining gross gonadal morphology under a dissecting microscope. Also sex reversal ratio and growth performance were determined in hormone-treated groups. These sex reversed functional males were reared for brood stock until they attained sexual maturity. At the end of experiment, normal rainbow trout eggs were fertilized with the sperms taken from sex reversed males for producing all-female populations. Examination of the results showed that 17α- methyltestosterone was effective in all treatment. The highest sex reversal ratio with 100% was observed in group treated with 0.5, 1.5 and 3 mg/kg 17α- methyltestosterone. The highest live weight ratios were observed in groups fed with 6, 0.5 17α-methyltestosterone and control group. Female progeny produced from the sex reversed males were 100 % in all males that sired offspring. All female trout stocks produced by this method have advantage in rainbow trout culture since the fish is not meant for direct human consumption and is used to generate brood stock, therefore, difference of growth parameters do not influence the success

    Aberrant iPSC-derived human astrocytes in Alzheimer's disease

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    The pathological potential of human astroglia in Alzheimer's disease (AD) was analysed in vitro using induced pluripotent stem cell (iPSC) technology. Here, we report development of a human iPSC-derived astrocyte model created from healthy individuals and patients with either early-onset familial AD (FAD) or the late-onset sporadic form of AD (SAD). Our chemically-defined and highly efficient model provides >95% homogeneous populations of human astrocytes within 30 days of differentiation from cortical neural progenitor cells (NPCs). All astrocytes expressed functional markers including; glial fibrillary acidic protein (GFAP), excitatory amino acid transporter 1 (EAAT1), S100B and glutamine synthetase (GS) comparable to that of adult astrocytes in vivo. However, induced astrocytes derived from both SAD and FAD patients exhibit a pronounced pathological phenotype, with a significantly less complex morphological appearance, overall atrophic profiles, and abnormal localisation of key functional astroglial markers. Furthermore, NPCs derived from identical patients did not show any differences, therefore, validating that remodelled astroglia are not as a result of defective neuronal intermediates. This work not only presents a novel model to study the mechanisms of human astrocytes in vitro, but also provides an ideal platform for further interrogation of early astroglial cell-autonomous events in AD and the possibility of identification of novel therapeutic targets for the treatment of AD
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