Early blood retinal barrier (BRB) dysfunction induced by hyperglycemia was related to increased pro-inflammatory activity of phospholipase A2 (PLA2) and the upregulation of vascular endothelial growth factor A (VEGF-A). Here, we tested the role of VEGF-A in high glucose (HG)-induced damage of human retinal endothelial cells (HRECs) mediated by Ca++-dependent (cPLA2) and Ca++-independent (iPLA2) PLA2s. HRECs were treated with normal glucose (5 mM, NG) or high glucose (25 mM, HG) for 48 h with or without the VEGF-trap Aflibercept (Afl, 40 µg/mL), the cPLA2 inhibitor arachidonoyl trifluoromethyl ketone (AACOCF3; 15 µM), the iPLA2 inhibitor bromoenol lactone (BEL; 5 µM), or VEGF-A (80 ng/mL). Both Afl and AACOCF3 prevented HG-induced damage (MTT and LDH release), impairment of angiogenic potential (tube-formation), and expression of VEGF-A mRNA. Furthermore, Afl counteracted HG-induced increase of phospho-ERK and phospho-cPLA2 (immunoblot). VEGF-A in HG-medium increased glucose toxicity, through upregulation of phospho-ERK, phospho-cPLA2, and iPLA2 (about 55%, 45%, and 50%, respectively); immunocytochemistry confirmed the activation of these proteins. cPLA2 knockdown by siRNA entirely prevented cell damage induced by HG or by HG plus VEGF-A, while iPLA2 knockdown produced a milder protective effect. These data indicate that VEGF-A mediates the early glucose-induced damage in retinal endothelium through the involvement of ERK1/2/PLA2 axis activation.

Activation of the VEGF-A/ERK/PLA2 axis mediates early retinal endothelial cell damage induced by high glucose: New insight from an in vitro model of diabetic retinopathy

Giurdanella G.;Lupo G.;Conti F.;Lo Furno D.;Mannino G.;Anfuso C. D.;Drago F.;Salomone S.
;
Bucolo C.
2020-01-01

Abstract

Early blood retinal barrier (BRB) dysfunction induced by hyperglycemia was related to increased pro-inflammatory activity of phospholipase A2 (PLA2) and the upregulation of vascular endothelial growth factor A (VEGF-A). Here, we tested the role of VEGF-A in high glucose (HG)-induced damage of human retinal endothelial cells (HRECs) mediated by Ca++-dependent (cPLA2) and Ca++-independent (iPLA2) PLA2s. HRECs were treated with normal glucose (5 mM, NG) or high glucose (25 mM, HG) for 48 h with or without the VEGF-trap Aflibercept (Afl, 40 µg/mL), the cPLA2 inhibitor arachidonoyl trifluoromethyl ketone (AACOCF3; 15 µM), the iPLA2 inhibitor bromoenol lactone (BEL; 5 µM), or VEGF-A (80 ng/mL). Both Afl and AACOCF3 prevented HG-induced damage (MTT and LDH release), impairment of angiogenic potential (tube-formation), and expression of VEGF-A mRNA. Furthermore, Afl counteracted HG-induced increase of phospho-ERK and phospho-cPLA2 (immunoblot). VEGF-A in HG-medium increased glucose toxicity, through upregulation of phospho-ERK, phospho-cPLA2, and iPLA2 (about 55%, 45%, and 50%, respectively); immunocytochemistry confirmed the activation of these proteins. cPLA2 knockdown by siRNA entirely prevented cell damage induced by HG or by HG plus VEGF-A, while iPLA2 knockdown produced a milder protective effect. These data indicate that VEGF-A mediates the early glucose-induced damage in retinal endothelium through the involvement of ERK1/2/PLA2 axis activation.
Aflibercept
High glucose
Phospholipase A2
Retinal endothelium
VEGF-A
File in questo prodotto:
File Dimensione Formato  
ijms-21-07528.pdf

accesso aperto

Tipologia: Versione Editoriale (PDF)
Dimensione 2.87 MB
Formato Adobe PDF
2.87 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11769/485052
Citazioni
  • ???jsp.display-item.citation.pmc??? 13
  • Scopus 24
  • ???jsp.display-item.citation.isi??? ND
social impact