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  1. Article ; Online: Calpain mediates epithelial cell microvillar effacement by enterohemorrhagic Escherichia coli

    JohnMLeong / IraM.Herman

    Frontiers in Microbiology, Vol

    2011  Volume 2

    Abstract: A member of the attaching and effacing (AE) family of pathogens, enterohemorrhagic Escherichia coli (EHEC) induces dramatic changes to the intestinal cell cytoskeleton, including effacement of microvilli. Effacement by the related pathogen ... ...

    Abstract A member of the attaching and effacing (AE) family of pathogens, enterohemorrhagic Escherichia coli (EHEC) induces dramatic changes to the intestinal cell cytoskeleton, including effacement of microvilli. Effacement by the related pathogen enteropathogenic E. coli (EPEC) requires the activity of the Ca+2-dependent host protease, calpain, which participates in a variety of cellular processes, including cell adhesion and motility. We found that EHEC infection results in an increase in epithelial (CaCo-2a) cell calpain activity and that EHEC-induced microvillar effacement was blocked by ectopic expression of calpastatin, an endogenous calpain inhibitor, or by pretreatment of intestinal cells with a cell-penetrating version of calpastatin. In addition, ezrin, a known calpain substrate that links the plasma membrane to axial actin filaments in microvilli, was cleaved in a calpain-dependent manner during EHEC infection and lost from its normal locale within microvilli. Calpain may be a central conduit through which EHEC and other AE pathogens induce enterocyte cytoskeletal remodeling and exert their pathogenic effects.
    Keywords Microvilli ; attaching and effacing (AE) lesion ; CaCo-2 ; Calpastat ; calpastatin ; Ezrin ; Microbiology ; QR1-502 ; Science ; Q
    Language English
    Publishing date 2011-11-01T00:00:00Z
    Publisher Frontiers Media S.A.
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Pro-atherosclerotic disturbed flow disrupts caveolin-1 expression, localization, and function via glycocalyx degradation

    Ian C. Harding / Ronodeep Mitra / Solomon A. Mensah / Ira M. Herman / Eno E. Ebong

    Journal of Translational Medicine, Vol 16, Iss 1, Pp 1-

    2018  Volume 20

    Abstract: Abstract Background Endothelial-dependent atherosclerosis develops in a non-random pattern in regions of vessel bending and bifurcations, where blood flow exhibits disturbed flow (DF) patterns. In contrast, uniform flow (UF), normal endothelium, and ... ...

    Abstract Abstract Background Endothelial-dependent atherosclerosis develops in a non-random pattern in regions of vessel bending and bifurcations, where blood flow exhibits disturbed flow (DF) patterns. In contrast, uniform flow (UF), normal endothelium, and healthy vessel walls co-exist within straight vessels. In clarifying how flow protectively or atherogenically regulates endothelial cell behavior, involvement of the endothelial surface glycocalyx has been suggested due to reduced expression in regions of atherosclerosis development. Here, we hypothesized that pro-atherosclerotic endothelial dysfunction occurs as a result of DF-induced reduction in glycocalyx expression and subsequently impairs endothelial sensitivity to flow. Specifically, we propose that glycocalyx degradation can induce pro-atherosclerotic endothelial dysfunction through decreased caveolin-1 and endothelial nitric oxide synthase expression and localization. Methods We studied endothelial cells in atherosclerotic-prone DF and atherosclerotic-resistant UF conditions in parallel plate flow culture and in C57Bl/6 mice. The effects of flow conditioning on endothelial cell behavior were quantified using immunocytochemistry. The glycocalyx was fluorescently labeled for wheat germ agglutinin, which serves as a general glycocalyx label, and heparan sulfate, a major glycocalyx component. Additionally, mechanosensitivity was assessed by immunocytochemical fluorescence expression and function of caveolin-1, the protein that forms the mechanosignaling caveolar invaginations on the endothelial surface, total endothelial-type nitric oxide synthase (eNOS), which synthesizes nitric oxide, and serine 1177 phosphorylated eNOS (eNOS-pS1177), which is the active form of eNOS. Caveolin function and eNOS expression and activation were correlated to glycocalyx expression. Heparinase III enzyme was used to degrade a major glycocalyx component, HS, to identify the role of the glycocalyx in caveoin-1 and eNOS-pS1177 regulation. Results Results confirmed that DF reduces ...
    Keywords Atherosclerosis ; Endothelial cells ; Fluid shear stress ; Glycocalyx ; Caveolin ; Endothelial-type nitric oxide synthase ; Medicine ; R
    Subject code 570
    Language English
    Publishing date 2018-12-01T00:00:00Z
    Publisher BMC
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Tumor Angiogenesis

    Ira M. Herman / Fernando Nussenbaum

    Journal of Oncology, Vol

    Insights and Innovations

    2010  Volume 2010

    Keywords Neoplasms. Tumors. Oncology. Including cancer and carcinogens ; RC254-282 ; Internal medicine ; RC31-1245 ; Medicine ; R ; DOAJ:Oncology ; DOAJ:Medicine (General) ; DOAJ:Health Sciences
    Language English
    Publishing date 2010-01-01T00:00:00Z
    Publisher Hindawi Publishing Corporation
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Vascular Complications and Diabetes

    Abbott L. Willard / Ira M. Herman

    Journal of Ophthalmology, Vol

    Current Therapies and Future Challenges

    2012  Volume 2012

    Keywords Ophthalmology ; RE1-994 ; Medicine ; R ; DOAJ:Ophthalmology ; DOAJ:Medicine (General) ; DOAJ:Health Sciences
    Language English
    Publishing date 2012-01-01T00:00:00Z
    Publisher Hindawi Publishing Corporation
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: Identification and Characterization of Novel Matrix-Derived Bioactive Peptides

    Anthony R Sheets / Tatiana N Demidova-Rice / Lei Shi / Vincent Ronfard / Komel V Grover / Ira M Herman

    PLoS ONE, Vol 11, Iss 7, p e

    A Role for Collagenase from Santyl® Ointment in Post-Debridement Wound Healing?

    2016  Volume 0159598

    Abstract: Debridement, the removal of diseased, nonviable tissue, is critical for clinicians to readily assess wound status and prepare the wound bed for advanced therapeutics or downstream active healing. Removing necrotic slough and eschar through surgical or ... ...

    Abstract Debridement, the removal of diseased, nonviable tissue, is critical for clinicians to readily assess wound status and prepare the wound bed for advanced therapeutics or downstream active healing. Removing necrotic slough and eschar through surgical or mechanical methods is less specific and may be painful for patients. Enzymatic debridement agents, such as Clostridial collagenase, selectively and painlessly degrade devitalized tissue. In addition to its debriding activities, highly-purified Clostridial collagenase actively promotes healing, and our past studies reveal that extracellular matrices digested with this enzyme yield peptides that activate cellular migratory, proliferative and angiogenic responses to injury in vitro, and promote wound closure in vivo. Intriguingly, while collagenase Santyl® ointment, a sterile preparation containing Clostridial collagenases and other non-specific proteases, is a well-accepted enzymatic debridement agent, its role as an active healing entity has never been established. Based on our previous studies of pure Clostridial collagenase, we now ask whether the mixture of enzymes contained within Santyl® produces matrix-derived peptides that promote cellular injury responses in vitro and stimulate wound closure in vivo. Here, we identify novel collagen fragments, along with collagen-associated peptides derived from thrombospondin-1, multimerin-1, fibronectin, TGFβ-induced protein ig-h3 and tenascin-C, generated from Santyl® collagenase-digested human dermal capillary endothelial and fibroblastic matrices, which increase cell proliferation and angiogenic remodeling in vitro by 50-100% over controls. Using an established model of impaired healing, we further demonstrate a specific dose of collagenase from Santyl® ointment, as well as the newly-identified and chemically-synthesized ECM-derived peptides significantly increase wound re-epithelialization by 60-100% over saline-treated controls. These results not only confirm and extend our earlier studies using purified collagenase- ...
    Keywords Medicine ; R ; Science ; Q
    Subject code 610
    Language English
    Publishing date 2016-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Human platelet-rich plasma- and extracellular matrix-derived peptides promote impaired cutaneous wound healing in vivo.

    Tatiana N Demidova-Rice / Lindsey Wolf / Jeffry Deckenback / Michael R Hamblin / Ira M Herman

    PLoS ONE, Vol 7, Iss 2, p e

    2012  Volume 32146

    Abstract: Previous work in our laboratory has described several pro-angiogenic short peptides derived from endothelial extracellular matrices degraded by bacterial collagenase. Here we tested whether these peptides could stimulate wound healing in vivo. Our ... ...

    Abstract Previous work in our laboratory has described several pro-angiogenic short peptides derived from endothelial extracellular matrices degraded by bacterial collagenase. Here we tested whether these peptides could stimulate wound healing in vivo. Our experiments demonstrated that a peptide created as combination of fragments of tenascin X and fibrillin 1 (comb1) applied into cranial dermal wounds created in mice treated with cyclophosphamide to impair wound healing, can improve the rate of wound closure. Furthermore, we identify and characterize a novel peptide (UN3) created and modified from two naturally-occurring peptides, which are present in human platelet-rich plasma. In vitro testing of UN3 demonstrates that it causes a 50% increase in endothelial proliferation, 250% increase in angiogenic response and a tripling of epithelial cell migration in response to injury. Results of in vivo experiments where comb1 and UN3 peptides were added together to cranial wounds in cyclophosphamide-treated mice leads to improvement of wound vascularization as shown by an increase of the number of blood vessels present in the wound beds. Application of the peptides markedly promotes cellular responses to injury and essentially restores wound healing dynamics to those of normal, acute wounds in the absence of cyclophosphamide impairment. Our current work is aimed at understanding the mechanisms underlying the stimulatory effects of these peptides as well as identification of the cellular receptors mediating these effects.
    Keywords Medicine ; R ; Science ; Q
    Subject code 610
    Language English
    Publishing date 2012-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: Pericytes derived from adipose-derived stem cells protect against retinal vasculopathy.

    Thomas A Mendel / Erin B D Clabough / David S Kao / Tatiana N Demidova-Rice / Jennifer T Durham / Brendan C Zotter / Scott A Seaman / Stephen M Cronk / Elizabeth P Rakoczy / Adam J Katz / Ira M Herman / Shayn M Peirce / Paul A Yates

    PLoS ONE, Vol 8, Iss 5, p e

    2013  Volume 65691

    Abstract: Retinal vasculopathies, including diabetic retinopathy (DR), threaten the vision of over 100 million people. Retinal pericytes are critical for microvascular control, supporting retinal endothelial cells via direct contact and paracrine mechanisms. With ... ...

    Abstract Retinal vasculopathies, including diabetic retinopathy (DR), threaten the vision of over 100 million people. Retinal pericytes are critical for microvascular control, supporting retinal endothelial cells via direct contact and paracrine mechanisms. With pericyte death or loss, endothelial dysfunction ensues, resulting in hypoxic insult, pathologic angiogenesis, and ultimately blindness. Adipose-derived stem cells (ASCs) differentiate into pericytes, suggesting they may be useful as a protective and regenerative cellular therapy for retinal vascular disease. In this study, we examine the ability of ASCs to differentiate into pericytes that can stabilize retinal vessels in multiple pre-clinical models of retinal vasculopathy.We found that ASCs express pericyte-specific markers in vitro. When injected intravitreally into the murine eye subjected to oxygen-induced retinopathy (OIR), ASCs were capable of migrating to and integrating with the retinal vasculature. Integrated ASCs maintained marker expression and pericyte-like morphology in vivo for at least 2 months. ASCs injected after OIR vessel destabilization and ablation enhanced vessel regrowth (16% reduction in avascular area). ASCs injected intravitreally before OIR vessel destabilization prevented retinal capillary dropout (53% reduction). Treatment of ASCs with transforming growth factor beta (TGF-β1) enhanced hASC pericyte function, in a manner similar to native retinal pericytes, with increased marker expression of smooth muscle actin, cellular contractility, endothelial stabilization, and microvascular protection in OIR. Finally, injected ASCs prevented capillary loss in the diabetic retinopathic Akimba mouse (79% reduction 2 months after injection).ASC-derived pericytes can integrate with retinal vasculature, adopting both pericyte morphology and marker expression, and provide functional vascular protection in multiple murine models of retinal vasculopathy. The pericyte phenotype demonstrated by ASCs is enhanced with TGF-β1 treatment, as seen with native retinal pericytes. ASCs may represent an innovative cellular therapy for protection against and repair of DR and other retinal vascular diseases.
    Keywords Medicine ; R ; Science ; Q
    Subject code 610
    Language English
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article ; Online: Correction

    Thomas A. Mendel / Erin B. D. Clabough / David S. Kao / Tatiana N. Demidova-Rice / Jennifer T. Durham / Brendan C. Zotter / Scott A. Seaman / Stephen M. Cronk / Elizabeth P. Rakoczy / Adam J. Katz / Ira M. Herman / Shayn M. Peirce / Paul A. Yates

    PLoS ONE, Vol 8, Iss

    Pericytes Derived from Adipose-Derived Stem Cells Protect against Retinal Vasculopathy.

    2013  Volume 9

    Keywords Medicine ; R ; Science ; Q
    Language English
    Publishing date 2013-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Article ; Online: Correction

    Thomas A. Mendel / Erin B. D. Clabough / David S. Kao / Tatiana N. Demidova-Rice / Jennifer T. Durham / Brendan C. Zotter / Scott A. Seaman / Stephen M. Cronk / Elizabeth P. Rakoczy / Adam J. Katz / Ira M. Herman / Shayn M. Peirce / Paul A. Yates

    PLoS ONE, Vol 8, Iss

    Pericytes Derived from Adipose-Derived Stem Cells Protect against Retinal Vasculopathy

    2013  Volume 9

    Keywords Medicine ; R ; Science ; Q
    Language English
    Publishing date 2013-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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