Biomedical subjects
Edwin L Cooper
Publications and source records attributed to Edwin L Cooper.
Characterization of cells with different mitochondrial membrane potential during apoptosis.
BACKGROUND: Until now, the simultaneous analysis of several parameters during apoptosis, including DNA content and mitochondrial membrane potential (DeltaPsi), has not been possible because of the spectral characteristics of the commonly used dyes. Using polychromatic flow cytometry based upon multiple laser and UV lamp excitation, we have characterized cells with different DeltaPsi during apoptosis. METHODS: U937 cells were treated with the flavonoid quercetin (Qu) and stained with JC-1 to detect DeltaPsi, propidium iodide (PI) for cell viability, Hoechst 33342 for DNA content, Annexin V conjugated with Alexa Fluor-647 for detection of phosphatidilserine (PS) exposure, marker of early apoptosis, or Mitotracker Deep Red for the determination of mitochondrial mass. RESULTS: Treatment with Qu provoked the onset of three cell populations with different DeltaPsi: (1) healthy cells, with normal DeltaPsi, DNA content and physical parameters, high mitochondrial mass, PI- and Annexin V-negative; (2) cells with intermediate DeltaPsi and normal DNA content, but with physical parameters typical of apoptotic cells and low mitochondrial mass; most of them were PI+ and Annexin V+; (3) cells with collapsed DeltaPsi that had low mitochondrial mass and were Annexin-V+, PI+; half of them showed diminished DNA content. Similar results, i.e. the presence of cells with intermediate DeltaPsi, were observed in other models of apoptosis. CONCLUSIONS: During Qu-induced apoptosis, loss of DeltaPsi, PS exposure, and decrease of mitochondrial mass are early events that precede permeability to PI and loss of DNA. Populations of cells with different DeltaPsi, as revealed by flow cytometry after JC-1 staining, differed also for other parameters associated to apoptosis. Thus, the simultaneous analysis of several parameters by polychromatic flow cytometry permits a better identification of many stages of cell death, and, more in general, allows to evaluate the eventual heterogenic sensibility of the population under study to a given compound.
Essential requirement of reduced glutathione (GSH) for the anti-oxidant effect of the flavonoid quercetin.
We have analyzed the anti- or pro-oxidant effects of the flavonoid quercetin (QU) by evaluating, in U937 cell line, hydrogen peroxide (H(2)O(2)), superoxide anion reduced glutathione (GSH) content, mitochondrial membrane potential, DNA content, phosphatidylserine exposure on the outer face of the plasma membrane and cell viability. Polychromatic flow cytometry was used to evaluate in the same cells several functional parameters. For short periods of treatment QU exerted an anti-oxidant effect (decrease in H(2)O(2) levels), whereas for long periods it showed a pro-oxidant activity (increase in ). In these conditions, GSH content was reduced, and this correlated with a lack of anti-oxidant activity of QU, which in turn could be correlated with proapoptotic activity of this molecule. Thus, QU can exert different effects (anti-/prooxidant) depending on exposure times and oxidative balance, and in particular on stores of GSH.
Bioprospecting: a CAM Frontier.
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CAM, eCAM, Bioprospecting: The 21st Century Pyramid.
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eCAM benefits from diversity that derives from CAM.
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Monoclonal antibodies identify four distinct annelid leukocyte markers.
This paper describes for the first time the production and characterization of a library of monoclonal antibodies (anti-EFCC clones) raised against coelomocyte (leukocyte) markers of Eisenia fetida earthworm. Leukocyte subgroups are components of earthworm innate immunity that require a more precise characterization using immunological markers. Flow cytometry, immunocytochemistry, and immunoprecipitation analyzed and confirmed the specificity of anti-EFCC clones. Anti-EFCC mAbs revealed different leukocyte subpopulations and various staining patterns on tissues. Two functional assays (e.g. phagocytosis and encapsulation) further characterized EFCC clusters revealing a common coelomocyte marker and three subpopulation-specific markers. No crossreactivity was found on human, mouse, rat or cells from Drosophila melanogaster but immunoreactivity was detected on snail (Planorbarius corneus) tissues. Immunohistochemical results suggest mesodermal origin of all coelomocyte subgroups that agree with classical morphological analyses.
Commentary on Traditional and Modern Biomedical Prospecting: Part II-The Benefits by Werner E.G. Muller, Heinz C. Schroder, Matthias Wiens, Sanja Perovic-Ottstadt, Renato Batel and Isabel M. Muller: Anti-protozoa and antiviral activities of non-cytotoxic truncated and variant analogues of mussel defensin by P. Roch, A. Beschin and E. Bernard.
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Sex-specific effects of carotenoid intake on the immunological response to allografts in guppies (Poecilia reticulata).
Rarely are the evolutionary origins of mate preferences known, but, recently, the preference of female guppies (Poecilia reticulata) for males with carotenoid-based sexual coloration has been linked to a sensory bias that may have originally evolved for detecting carotenoid-rich fruits. If carotenoids enhance the immune systems of these fishes, as has been suggested for other species, this could explain the origin of the attraction to orange fruits as well as the maintenance of the female preference for orange males. We used the classic immunological technique of tissue grafting to assay a component of the immune response of guppies raised on two different dietary levels of carotenoids. Individual scales were transplanted between pairs of unrelated fishes, creating reciprocal allografts. Transplanted scales were scored on a six-point rejection scale every day for 10 days. Five days later, the same pairs of fishes received a second set of allografts and were scored again. Compared with low-carotenoid-diet males, high-carotenoid-diet males mounted a significantly stronger rejection response to the second allograft but not to the first allograft. High-carotenoid-diet females, however, showed no improvement in graft rejection compared with low-carotenoid-diet females. To our knowledge, this is the first experimental evidence for sex-specific effects of carotenoid consumption on the immune system of a species with carotenoid-based sexual coloration. These results are consistent with the hypothesis that the mate preference for carotenoid coloration is maintained by the benefits to females of choosing healthy mates, but they cast doubt on the idea that the benefits of carotenoid consumption, per se, could account for the origin of the preference. The sex-specificity of carotenoid effects on allograft rejection in guppies provides indirect support for the general hypothesis that males pay an immunological cost for sexual ornamentation.
Earthworms: sources of antimicrobial and anticancer molecules.
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Nervous, endocrine, immune systems as a target for complementary and alternative medicine.
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Identification of diseases that may be targets for complementary and alternative medicine (CAM).
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Drug Discovery, CAM and Natural Products.
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Heat shock protein and gliadin peptide promote development of peptidase antibodies in children with autism and patients with autoimmune disease.
Searching for a mechanism underlying autoimmunity in autism, we postulated that gliadin peptides, heat shock protein 60 (HSP-60), and streptokinase (SK) bind to different peptidases resulting in autoantibody production against these components. We assessed this hypothesis in patients with autism and in those with mixed connective tissue diseases. Associated with antigliadin and anti-HSP antibodies, children with autism and patients with autoimmune disease developed anti-dipeptidylpeptidase I (DPP I), anti-dipeptidylpeptidase IV (DPP IV [or CD26]) and anti-aminopeptidase N (CD13) autoantibodies. A significant percentage of autoimmune and autistic sera were associated with elevated immunoglobulin G (IgG), IgM, or IgA antibodies against three peptidases, gliadin, and HSP-60. These antibodies are specific, since immune absorption demonstrated that only specific antigens (e.g., DPP IV absorption of anti-DPP IV), significantly reduced IgG, IgM, and IgA antibody levels. For direct demonstration of SK, HSP-60, and gliadin peptide binding to DPP IV, microtiter wells coated with DPP IV were reacted with SK, HSP-60, and gliadin. They were then reacted with anti-DPP IV or anti-SK, anti-HSP, and antigliadin antibodies. Adding SK, HSP-60, and gliadin peptides to DPP IV resulted in 27 to 43% inhibition of the DPP IV-anti-DPP IV reaction, but DPP IV-positive peptides caused 18 to 20% enhancement of antigen-antibody reactions. We propose that (i) superantigens (e.g., SK and HSP-60) and dietary proteins (e.g., gliadin peptides) in individuals with predisposing HLA molecules bind to aminopeptidases and (ii) they induce autoantibodies to peptides and tissue antigens. Dysfunctional membrane peptidases and autoantibody production may result in neuroimmune dysregulation and autoimmunity.
Leech responses to tissue transplantation.
The aim of the present work is to describe histologically, histochemically and immunocytochemically, the sequence of events that lead to first and second set rejection of allo- or xenograft in leeches. Graft responses of leeches are comparable and are described following specific steps: inflammatory phase, rejection phase and granulation tissue formation (including re-epithelialisation, angiogenesis and fibroplasia).The responses to first and second graft in first set graft rejection as well as to the first transplant in second set graft experiments are identical and in the time span of a week all grafts are destroyed and disappear. In the second set graft rejection experiments the responses against the second transplant are markedly accelerated. The second graft shows massive structural alterations and it is rapidly rejected, within 3-4 days.Our results permit to highlight that in leeches there is a specific responsiveness of immune system similar to those described in highly divergent phyla.