The Cx43 Carboxyl-Terminal Mimetic Peptide αCT1 Protects Endothelial Barrier Function in a ZO1 Binding-Competent Manner
The Cx43 carboxyl-terminus (CT) mimetic peptide, αCT1, originally designed to bind to Zonula Occludens 1 (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 v...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-08-01
|
| Series: | Biomolecules |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2218-273X/11/8/1192 |
| _version_ | 1797524505985286144 |
|---|---|
| author | Randy E. Strauss Louisa Mezache Rengasayee Veeraraghavan Robert G. Gourdie |
| author_facet | Randy E. Strauss Louisa Mezache Rengasayee Veeraraghavan Robert G. Gourdie |
| author_sort | Randy E. Strauss |
| collection | DOAJ |
| description | The Cx43 carboxyl-terminus (CT) mimetic peptide, αCT1, originally designed to bind to Zonula Occludens 1 (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 chiral 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. |
| first_indexed | 2024-03-10T08:58:22Z |
| format | Article |
| id | doaj.art-573d746bb0bc40f094cc3ad7aeb9ff75 |
| institution | Directory Open Access Journal |
| issn | 2218-273X |
| language | English |
| last_indexed | 2024-03-10T08:58:22Z |
| publishDate | 2021-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Biomolecules |
| spelling | doaj.art-573d746bb0bc40f094cc3ad7aeb9ff752023-11-22T06:56:09ZengMDPI AGBiomolecules2218-273X2021-08-01118119210.3390/biom11081192The Cx43 Carboxyl-Terminal Mimetic Peptide αCT1 Protects Endothelial Barrier Function in a ZO1 Binding-Competent MannerRandy E. Strauss0Louisa Mezache1Rengasayee Veeraraghavan2Robert G. Gourdie3Virginia Tech, Translational Biology Medicine and Health (TBMH) Program, Roanoke, VA 24016, USADepartment of Biomedical Engineering, College of Engineering, The Ohio State University, 460 Medical Center Dr., Rm 415A, IBMR, Columbus, OH 43210, USADepartment of Biomedical Engineering, College of Engineering, The Ohio State University, 460 Medical Center Dr., Rm 415A, IBMR, Columbus, OH 43210, USACenter for Heart and Reparative Medicine Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016, USAThe Cx43 carboxyl-terminus (CT) mimetic peptide, αCT1, originally designed to bind to Zonula Occludens 1 (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 chiral 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.https://www.mdpi.com/2218-273X/11/8/1192Cx43Zonula Occludens 1barrier functiontight junctionsadherens junctionsactin cytoskeleton |
| spellingShingle | Randy E. Strauss Louisa Mezache Rengasayee Veeraraghavan Robert G. Gourdie The Cx43 Carboxyl-Terminal Mimetic Peptide αCT1 Protects Endothelial Barrier Function in a ZO1 Binding-Competent Manner Biomolecules Cx43 Zonula Occludens 1 barrier function tight junctions adherens junctions actin cytoskeleton |
| title | The Cx43 Carboxyl-Terminal Mimetic Peptide αCT1 Protects Endothelial Barrier Function in a ZO1 Binding-Competent Manner |
| title_full | The Cx43 Carboxyl-Terminal Mimetic Peptide αCT1 Protects Endothelial Barrier Function in a ZO1 Binding-Competent Manner |
| title_fullStr | The Cx43 Carboxyl-Terminal Mimetic Peptide αCT1 Protects Endothelial Barrier Function in a ZO1 Binding-Competent Manner |
| title_full_unstemmed | The Cx43 Carboxyl-Terminal Mimetic Peptide αCT1 Protects Endothelial Barrier Function in a ZO1 Binding-Competent Manner |
| title_short | The Cx43 Carboxyl-Terminal Mimetic Peptide αCT1 Protects Endothelial Barrier Function in a ZO1 Binding-Competent Manner |
| title_sort | cx43 carboxyl terminal mimetic peptide αct1 protects endothelial barrier function in a zo1 binding competent manner |
| topic | Cx43 Zonula Occludens 1 barrier function tight junctions adherens junctions actin cytoskeleton |
| url | https://www.mdpi.com/2218-273X/11/8/1192 |
| work_keys_str_mv | AT randyestrauss thecx43carboxylterminalmimeticpeptideact1protectsendothelialbarrierfunctioninazo1bindingcompetentmanner AT louisamezache thecx43carboxylterminalmimeticpeptideact1protectsendothelialbarrierfunctioninazo1bindingcompetentmanner AT rengasayeeveeraraghavan thecx43carboxylterminalmimeticpeptideact1protectsendothelialbarrierfunctioninazo1bindingcompetentmanner AT robertggourdie thecx43carboxylterminalmimeticpeptideact1protectsendothelialbarrierfunctioninazo1bindingcompetentmanner AT randyestrauss cx43carboxylterminalmimeticpeptideact1protectsendothelialbarrierfunctioninazo1bindingcompetentmanner AT louisamezache cx43carboxylterminalmimeticpeptideact1protectsendothelialbarrierfunctioninazo1bindingcompetentmanner AT rengasayeeveeraraghavan cx43carboxylterminalmimeticpeptideact1protectsendothelialbarrierfunctioninazo1bindingcompetentmanner AT robertggourdie cx43carboxylterminalmimeticpeptideact1protectsendothelialbarrierfunctioninazo1bindingcompetentmanner |