The possible link between high glucose-induced PKCβ expression and the appearance of GLP-1 resistance in endothelial cells

[eng] INTRODUCTION. It has been demonstrated that Glucagon-like peptide-1 (GPL-1) has a protective effect on endothelial cells. GLP-1 improves endothelial function in diabetes, however the mechanisms underlying the GLP-1 protective effects have not yet been fully elucidated. Additionally, it has bee...

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Autor: De Nigris, Valeria
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2015
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/68388
Acceso en línea:https://hdl.handle.net/2445/68388
http://tdx.cat/handle/10803/325682
Access Level:acceso abierto
Palabra clave:Diabetis
Hiperglucèmia
Endoteli
Diabetes
Hyperglycemia
Endothelium
id ES_f27df860e10cd0710b9ebd3712db75b3
oai_identifier_str oai:diposit.ub.edu:2445/68388
network_acronym_str ES
network_name_str España
repository_id_str
dc.title.none.fl_str_mv The possible link between high glucose-induced PKCβ expression and the appearance of GLP-1 resistance in endothelial cells
title The possible link between high glucose-induced PKCβ expression and the appearance of GLP-1 resistance in endothelial cells
spellingShingle The possible link between high glucose-induced PKCβ expression and the appearance of GLP-1 resistance in endothelial cells
De Nigris, Valeria
Diabetis
Hiperglucèmia
Endoteli
Diabetes
Hyperglycemia
Endothelium
title_short The possible link between high glucose-induced PKCβ expression and the appearance of GLP-1 resistance in endothelial cells
title_full The possible link between high glucose-induced PKCβ expression and the appearance of GLP-1 resistance in endothelial cells
title_fullStr The possible link between high glucose-induced PKCβ expression and the appearance of GLP-1 resistance in endothelial cells
title_full_unstemmed The possible link between high glucose-induced PKCβ expression and the appearance of GLP-1 resistance in endothelial cells
title_sort The possible link between high glucose-induced PKCβ expression and the appearance of GLP-1 resistance in endothelial cells
dc.creator.none.fl_str_mv De Nigris, Valeria
author De Nigris, Valeria
author_facet De Nigris, Valeria
author_role author
dc.contributor.none.fl_str_mv Ceriello, Antonio
Pujadas i Rovira, Gemma
Gomis, Ramon, 1946-
dc.subject.none.fl_str_mv Diabetis
Hiperglucèmia
Endoteli
Diabetes
Hyperglycemia
Endothelium
topic Diabetis
Hiperglucèmia
Endoteli
Diabetes
Hyperglycemia
Endothelium
description [eng] INTRODUCTION. It has been demonstrated that Glucagon-like peptide-1 (GPL-1) has a protective effect on endothelial cells. GLP-1 improves endothelial function in diabetes, however the mechanisms underlying the GLP-1 protective effects have not yet been fully elucidated. Additionally, it has been proposed that GLP-1 could restore high glucose - endoplasmic reticulum (ER) stress induction. Recent evidences claim a resistance of GLP-1 action that has been shown in pancreatic 13-cells of diabetic patients. A proposed mechanism to explain this resistance to the GLP-1 action in diabetes is the activation of PKCI3, induced by hyperglycaemia, which is able to reduce the expression of GLP-1 receptor. AIM. The aim of this thesis project was to decipher if GLP-1 acute treatment is able to counteract chronic high glucose-induced damage in Human umbilical Vein Endothelial cells (HUVECs). METHODS. In this study HUVECs were cultured for 21 days under normal glucose (5mmol/L, NG) or high glucose (25mmol/L glucose, HG) concentrations. GLP-1 and Ruboxistaurin were added alone or in combination, 1 hour before cell harvesting. Analysis of GLP-1 receptor protein levels as well as of gene expression of different ER stress-related genes, proliferation markers, antioxidant cell response-related genes and PKA subunits was performed. ROS production was also measured in HUVECs exposed to mentioned treatments. RESULTS. GLP-1 receptor expression was reduced in HUVECs exposed to chronic high glucose concentrations and it was partially restored after treatment with the chemical PKCI3 specific inhibitor, Ruboxistaurin. GLP-1, added as an acute treatment in endothelial cells, had the capacity to induce the expression of detoxifying enzymes Nrf2 targets, to increase transcript levels of scavenger genes, to attenuate the high glucose-induced PKA subunits expression, ER stress and also the apoptotic phenotype of HUVECs only when high glucose-induced PKCI3 overexpression was reduced by Ruboxistaurin. In the same direction, ROS production induced by high glucose was reduced by GLP-1 in the presence of PKCI3 inhibitor. CONCLUSIONS. This study suggests that PKCI3 increase, induced by high glucose, could have a role in endothelial GLP-1 resistance, reducing GLP-1 receptor levels and disrupting GLP-1 canonical pathway.
publishDate 2015
dc.date.none.fl_str_mv 2015
dc.type.none.fl_str_mv info:eu-repo/semantics/doctoralThesis
info:eu-repo/semantics/publishedVersion
format doctoralThesis
status_str publishedVersion
dc.identifier.none.fl_str_mv https://hdl.handle.net/2445/68388
http://tdx.cat/handle/10803/325682
url https://hdl.handle.net/2445/68388
http://tdx.cat/handle/10803/325682
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.rights.none.fl_str_mv cc by-nc-nd (c) De Nigris, 2015
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
info:eu-repo/semantics/openAccess
rights_invalid_str_mv cc by-nc-nd (c) De Nigris, 2015
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Universitat de Barcelona
publisher.none.fl_str_mv Universitat de Barcelona
dc.source.none.fl_str_mv Tesis Doctorals - Facultat - Medicina
reponame:Dipòsit Digital de la UB
instname:Universidad de Barcelona
instname_str Universidad de Barcelona
reponame_str Dipòsit Digital de la UB
collection Dipòsit Digital de la UB
repository.name.fl_str_mv
repository.mail.fl_str_mv
_version_ 1869424285371596800
spelling The possible link between high glucose-induced PKCβ expression and the appearance of GLP-1 resistance in endothelial cellsDe Nigris, ValeriaDiabetisHiperglucèmiaEndoteliDiabetesHyperglycemiaEndothelium[eng] INTRODUCTION. It has been demonstrated that Glucagon-like peptide-1 (GPL-1) has a protective effect on endothelial cells. GLP-1 improves endothelial function in diabetes, however the mechanisms underlying the GLP-1 protective effects have not yet been fully elucidated. Additionally, it has been proposed that GLP-1 could restore high glucose - endoplasmic reticulum (ER) stress induction. Recent evidences claim a resistance of GLP-1 action that has been shown in pancreatic 13-cells of diabetic patients. A proposed mechanism to explain this resistance to the GLP-1 action in diabetes is the activation of PKCI3, induced by hyperglycaemia, which is able to reduce the expression of GLP-1 receptor. AIM. The aim of this thesis project was to decipher if GLP-1 acute treatment is able to counteract chronic high glucose-induced damage in Human umbilical Vein Endothelial cells (HUVECs). METHODS. In this study HUVECs were cultured for 21 days under normal glucose (5mmol/L, NG) or high glucose (25mmol/L glucose, HG) concentrations. GLP-1 and Ruboxistaurin were added alone or in combination, 1 hour before cell harvesting. Analysis of GLP-1 receptor protein levels as well as of gene expression of different ER stress-related genes, proliferation markers, antioxidant cell response-related genes and PKA subunits was performed. ROS production was also measured in HUVECs exposed to mentioned treatments. RESULTS. GLP-1 receptor expression was reduced in HUVECs exposed to chronic high glucose concentrations and it was partially restored after treatment with the chemical PKCI3 specific inhibitor, Ruboxistaurin. GLP-1, added as an acute treatment in endothelial cells, had the capacity to induce the expression of detoxifying enzymes Nrf2 targets, to increase transcript levels of scavenger genes, to attenuate the high glucose-induced PKA subunits expression, ER stress and also the apoptotic phenotype of HUVECs only when high glucose-induced PKCI3 overexpression was reduced by Ruboxistaurin. In the same direction, ROS production induced by high glucose was reduced by GLP-1 in the presence of PKCI3 inhibitor. CONCLUSIONS. This study suggests that PKCI3 increase, induced by high glucose, could have a role in endothelial GLP-1 resistance, reducing GLP-1 receptor levels and disrupting GLP-1 canonical pathway.[spa] INTRODUCCIÓN. Se ha demostrado que el Glucagon-like peptide-1 (GLP-1) tiene un efecto protector sobre las células endoteliales. GLP-1 mejora la función endotelial en la diabetes, sin embargo los mecanismos subyacentes a los efectos protectores de GLP-1 aún no han sido completamente aclarada. Además, se ha propuesto que el GLP-1 podría restaurar la función del retículo endoplasmático (ER), cuyo estés es inducido en condiciones de alta glucosa. Evidencias recientes afirman que existe una resistencia a las propiedades beneficiosas del GLP-1. Esto se ha demostrado en las células beta del páncreas de pacientes diabéticos. Un mecanismo propuesto para explicar esta resistencia a la acción de GLP-1 en la diabetes es la activación de PKCβ, inducida por la hiperglucemia, que se ha visto está involucrada en la reducción de la expresión del receptor del GLP-1 en el endotelio glomerular de modelos animales de diabetes. OBJETIVO. El objetivo de este proyecto de tesis fue descifrar si el tratamiento agudo con GLP-1 puede contrarrestar el daño inducido por condiciones de alta glucosa crónica en las células endoteliales humanas de la vena umbilical (HUVECs) y también corroborar los efectos de dicha molécula en caso de que se inhiba la activación de PKCI3 inducida por las altas concentraciones de glucosa. MÉTODOS. En este estudio las células HUVEC se cultivaron durante 21 días bajo las dos condiciones de glucosa normal (5 mmol/L, NG) o alta glucosa (25 mmol/L, HG). Se añadieron GLP-1 y Ruboxistaurin, el inhibidor específico de PKCI3, solos o en combinación, 1 hora antes de la recolección de células. Se realizó un análisis de los niveles de proteína del receptor del GLP-1, así como de la expresión génica de diferentes relacionados con el estrés del ER, la proliferación, el proceso de apoptosis, y también los genes relacionados con la respuesta antioxidante. La producción de ROS fue además medida en las HUVECs expuestas a los diferentes tratamientos mencionados. RESULTADOS. La expresión del receptor del GLP-1 fue reducida en las HUVECs expuestas a concentraciones de alta glucosa crónica y fue parcialmente restaurada después del tratamiento con el inhibidor específico de PKCI3, Ruboxistaurin. GLP-1, añadido como un tratamiento agudo en las células endoteliales, tuvo la capacidad de inducir la expresión de enzimas desintoxicantes que son dianas de Nrf2, el regulador más importante de la respuesta antioxidante en las células. Además, el GLP-1 aumentó los niveles de transcriptos de los marcadores de estrés de ER inducido por la alta glucosa y los marcadores de proliferación en las HUVECs sólo cuando la sobreexpresión PKCβ inducida por la alta glucosa se redujo en presecia de su inhibidor. En la misma dirección, la producción de ROS inducida por la alta glucosa disminuyó cuando las HUVECs se trataron con GLP-1 en presencia del inhibidor de PKCI3. CONCLUSIONES. Este estudio sugiere que el aumento de PKCβ, inducido por la alta glucosa, podría tener un papel en la resistencia a las acciones protectoras del GLP-1 a nivel endotelial, reduciendo los niveles del receptor del GLP-1 e interrumpiendo su vía canónica.Universitat de BarcelonaCeriello, AntonioPujadas i Rovira, GemmaGomis, Ramon, 1946-2015info:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://hdl.handle.net/2445/68388http://tdx.cat/handle/10803/325682Tesis Doctorals - Facultat - Medicinareponame:Dipòsit Digital de la UBinstname:Universidad de BarcelonaIngléscc by-nc-nd (c) De Nigris, 2015http://creativecommons.org/licenses/by-nc-nd/3.0/es/info:eu-repo/semantics/openAccessoai:diposit.ub.edu:2445/683882026-05-27T06:46:51Z
score 15,198674

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