{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/107828"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/107828","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"The Cx43 Carboxyl-Terminal Mimetic Peptide αCT1 Protects Endothelial Barrier Function in a ZO1 Binding-Competent Manner","abstract":"The Cx43 CT mimetic peptide, αCT1, originally designed to bind to ZO1 and thereby inhibit Cx43/ZO1 interaction, was used as a tool to probe the role of Cx43/ZO1 association in regulation of epithelial/endothelial barrier function. Using both in vitro and ex vivo methods of barrier function measurement, including Electric Cell-Substrate Impedance Sensing(ECIS), a TRITC-dextran transwell permeability assay, and a FITC-dextran cardiovascular leakage protocol involving Langendorff-perfused mouse hearts, αCT1 was found to protect the endothelium from thrombin-induced breakdown in cell-cell contacts. Barrier protection was accompanied by significant remodeling of the F-actin cytoskeleton, characterized by a redistribution of F-actin away from the cytoplasmic and nuclear regions of the cell, towards the endothelial cell periphery, in association with alterations in cellular orientation distribution. In line with observations of increased cortical F-actin, αCT1 upregulated cell-cell border localization of endothelial VE-cadherin, the Tight Junction protein Zonula Occludens 1 (ZO1) , and the Gap Junction Protein (GJ) Connexin43 (Cx43). A ZO1-binding-incompetent variant of αCT1, αCT1-I, indicated that these effects on barrier function and barrier-associated proteins, were likely associated with Cx43 CT sequences retaining ability to interact with ZO1. These results implicate the Cx43 CT and its interaction with ZO1, in the regulation of endothelial barrier function, while revealing the therapeutic potential of αCT1 in the treatment of vascular edema.","abstract_html":"The Cx43 CT mimetic peptide, αCT1, originally designed to bind to ZO1 and thereby inhibit Cx43/ZO1 interaction, was used as a tool to probe the role of Cx43/ZO1 association in regulation of epithelial/endothelial barrier function. Using both in vitro and ex vivo methods of barrier function measurement, including Electric Cell-Substrate Impedance Sensing(ECIS), a TRITC-dextran transwell permeability assay, and a FITC-dextran cardiovascular leakage protocol involving Langendorff-perfused mouse hearts, αCT1 was found to protect the endothelium from thrombin-induced breakdown in cell-cell contacts. Barrier protection was accompanied by significant remodeling of the F-actin cytoskeleton, characterized by a redistribution of F-actin away from the cytoplasmic and nuclear regions of the cell, towards the endothelial cell periphery, in association with alterations in cellular orientation distribution. In line with observations of increased cortical F-actin, αCT1 upregulated cell-cell border localization of endothelial VE-cadherin, the Tight Junction protein Zonula Occludens 1 (ZO1) , and the Gap Junction Protein (GJ) Connexin43 (Cx43). A ZO1-binding-incompetent variant of αCT1, αCT1-I, indicated that these effects on barrier function and barrier-associated proteins, were likely associated with Cx43 CT sequences retaining ability to interact with ZO1. These results implicate the Cx43 CT and its interaction with ZO1, in the regulation of endothelial barrier function, while revealing the therapeutic potential of αCT1 in the treatment of vascular edema.","abstract_has_math":false,"creators":["Strauss, Randy E."],"institution":"Virginia Tech","degree_name":"Doctor of Philosophy","degree_level":"doctoral","degree_discipline":"Translational Biology, Medicine and Health","degree_department":"Graduate School","school":null,"contributors":[],"advisors":[],"committee_chairs":["Gourdie, Robert G."],"committee_members":["Chappell, John Christopher","Fox, Michael A.","Koval, Michael H.","Smyth, James"],"year":2022,"date_issued":"2022-01-20","date_published":"2022-01-20","updated_at":"2026-07-22T22:19:54Z","subjects":["Cx43","Zonula occludens 1","barrier function","tight junctions","adherens junctions","actin cytoskeleton","endothelial cells"],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:32679"],"render_values":[{"text":"vt_gsexam:32679","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/107828","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Gourdie, Robert G."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Chappell, John Christopher","Fox, Michael A.","Koval, Michael H.","Smyth, James"]},{"key":"dc:contributor.department","label":"Department","values":["Graduate School"]},{"key":"dc:creator","label":"Author","values":["Strauss, Randy E."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2022-01-21T09:00:14Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2022-01-21T09:00:14Z"]},{"key":"dc:date.issued","label":"Date","values":["2022-01-20"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Translational Biology, Medicine and Health"]},{"key":"thesis:degree_level","label":"Degree Level","values":["doctoral"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Cx43","Zonula occludens 1","barrier function","tight junctions","adherens junctions","actin cytoskeleton","endothelial cells"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:32679"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/107828"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The Cx43 CT mimetic peptide, αCT1, originally designed to bind to ZO1 and thereby inhibit Cx43/ZO1 interaction, was used as a tool to probe the role of Cx43/ZO1 association in regulation of epithelial/endothelial barrier function. Using both in vitro and ex vivo methods of barrier function measurement, including Electric Cell-Substrate Impedance Sensing(ECIS), a TRITC-dextran transwell permeability assay, and a FITC-dextran cardiovascular leakage protocol involving Langendorff-perfused mouse hearts, αCT1 was found to protect the endothelium from thrombin-induced breakdown in cell-cell contacts. Barrier protection was accompanied by significant remodeling of the F-actin cytoskeleton, characterized by a redistribution of F-actin away from the cytoplasmic and nuclear regions of the cell, towards the endothelial cell periphery, in association with alterations in cellular orientation distribution. In line with observations of increased cortical F-actin, αCT1 upregulated cell-cell border localization of endothelial VE-cadherin, the Tight Junction protein Zonula Occludens 1 (ZO1) , and the Gap Junction Protein (GJ) Connexin43 (Cx43). A ZO1-binding-incompetent variant of αCT1, αCT1-I, indicated that these effects on barrier function and barrier-associated proteins, were likely associated with Cx43 CT sequences retaining ability to interact with ZO1. These results implicate the Cx43 CT and its interaction with ZO1, in the regulation of endothelial barrier function, while revealing the therapeutic potential of αCT1 in the treatment of vascular edema."]},{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["Endothelial cells make up blood vessels within the heart and regulate the exchange of fluids between the circulation and heart tissue. In many forms of heart disease, the cardiac endothelium is disrupted, resulting in a damaging leakage and buildup of fluids within the heart. This work explores how a small peptide, derived from a naturally occurring molecule, may help to prevent fluid-associated damage to the heart by stabilizing the blood endothelium."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Doctor of Philosophy"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["The Cx43 Carboxyl-Terminal Mimetic Peptide αCT1 Protects Endothelial Barrier Function in a ZO1 Binding-Competent Manner"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Gourdie, Robert G."],"dc:contributor.committeemember":["Chappell, John Christopher","Fox, Michael A.","Koval, Michael H.","Smyth, James"],"dc:contributor.department":["Graduate School"],"dc:creator":["Strauss, Randy E."],"dc:date.accessioned":["2022-01-21T09:00:14Z"],"dc:date.available":["2022-01-21T09:00:14Z"],"dc:date.issued":["2022-01-20"],"dc:description.abstract":["The Cx43 CT mimetic peptide, αCT1, originally designed to bind to ZO1 and thereby inhibit Cx43/ZO1 interaction, was used as a tool to probe the role of Cx43/ZO1 association in regulation of epithelial/endothelial barrier function. Using both in vitro and ex vivo methods of barrier function measurement, including Electric Cell-Substrate Impedance Sensing(ECIS), a TRITC-dextran transwell permeability assay, and a FITC-dextran cardiovascular leakage protocol involving Langendorff-perfused mouse hearts, αCT1 was found to protect the endothelium from thrombin-induced breakdown in cell-cell contacts. Barrier protection was accompanied by significant remodeling of the F-actin cytoskeleton, characterized by a redistribution of F-actin away from the cytoplasmic and nuclear regions of the cell, towards the endothelial cell periphery, in association with alterations in cellular orientation distribution. In line with observations of increased cortical F-actin, αCT1 upregulated cell-cell border localization of endothelial VE-cadherin, the Tight Junction protein Zonula Occludens 1 (ZO1) , and the Gap Junction Protein (GJ) Connexin43 (Cx43). A ZO1-binding-incompetent variant of αCT1, αCT1-I, indicated that these effects on barrier function and barrier-associated proteins, were likely associated with Cx43 CT sequences retaining ability to interact with ZO1. These results implicate the Cx43 CT and its interaction with ZO1, in the regulation of endothelial barrier function, while revealing the therapeutic potential of αCT1 in the treatment of vascular edema."],"dc:description.abstractgeneral":["Endothelial cells make up blood vessels within the heart and regulate the exchange of fluids between the circulation and heart tissue. In many forms of heart disease, the cardiac endothelium is disrupted, resulting in a damaging leakage and buildup of fluids within the heart. This work explores how a small peptide, derived from a naturally occurring molecule, may help to prevent fluid-associated damage to the heart by stabilizing the blood endothelium."],"dc:description.degree":["Doctor of Philosophy"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:32679"],"dc:identifier.uri":["http://hdl.handle.net/10919/107828"],"dc:language.iso":["en"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Cx43","Zonula occludens 1","barrier function","tight junctions","adherens junctions","actin cytoskeleton","endothelial cells"],"dc:title":["The Cx43 Carboxyl-Terminal Mimetic Peptide αCT1 Protects Endothelial Barrier Function in a ZO1 Binding-Competent Manner"],"dc:type":["Dissertation"],"thesis:degree_discipline":["Translational Biology, Medicine and Health"],"thesis:degree_level":["doctoral"],"thesis:degree_name":["Doctor of Philosophy"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:54Z"}