TY - JOUR
T1 - Glucocorticoids exert differential effects on the endothelium in an in vitro model of the blood–retinal barrier
AU - van der Wijk, Anne-Eva
AU - Canning, Paul
AU - van Heijningen, Rutger
AU - Vogels, Ilse
AU - Van Noorden, C J F
AU - Klaassen, I.
AU - Schlingemann, Reinier O
PY - 2019/3/1
Y1 - 2019/3/1
N2 - PurposeGlucocorticoids (GCs) are used as treatment in diabetic macular oedema, a condition caused by blood–retinal barrier (BRB) disruption. The proposed mechanisms by which GCs reduce macular oedema are indirect anti‐inflammatory effects and inhibition of VEGF production, but direct effects on the BRB endothelium may be equally important. Here, we investigated direct effects of GCs on the endothelium to understand the specific pathways of GC action, to enable development of novel therapeutics lacking the adverse side‐effects of the presently used GCs.MethodsPrimary bovine retinal endothelial cells (BRECs) were grown on Transwell inserts and treated with hydrocortisone (HC), dexamethasone (Dex) or triamcinolone acetonide (TA). Molecular barrier integrity of the BRB was determined by mRNA and protein expression, and barrier function was assessed using permeability assays. In addition, we investigated whether TA was able to prevent barrier disruption after stimulation with VEGF or cytokines.ResultsTreatment of BRECs with GCs resulted in upregulation of tight junction mRNA (claudin‐5, occludin, ZO‐1) and protein (claudin‐5 and ZO‐1). In functional assays, only TA strengthened the barrier function by reducing endothelial permeability. Moreover, TA was able to prevent cytokine‐induced permeability in human retinal endothelial cells and VEGF‐induced expression of plasmalemma vesicle‐associated protein (PLVAP), a key player in VEGF‐induced retinal vascular leakage.ConclusionGlucocorticoids have differential effects in an experimental in vitro BRB model. TA is the most potent in improving barrier function, both at the molecular and functional levels, and TA prevents VEGF‐induced expression of PLVAP.
AB - PurposeGlucocorticoids (GCs) are used as treatment in diabetic macular oedema, a condition caused by blood–retinal barrier (BRB) disruption. The proposed mechanisms by which GCs reduce macular oedema are indirect anti‐inflammatory effects and inhibition of VEGF production, but direct effects on the BRB endothelium may be equally important. Here, we investigated direct effects of GCs on the endothelium to understand the specific pathways of GC action, to enable development of novel therapeutics lacking the adverse side‐effects of the presently used GCs.MethodsPrimary bovine retinal endothelial cells (BRECs) were grown on Transwell inserts and treated with hydrocortisone (HC), dexamethasone (Dex) or triamcinolone acetonide (TA). Molecular barrier integrity of the BRB was determined by mRNA and protein expression, and barrier function was assessed using permeability assays. In addition, we investigated whether TA was able to prevent barrier disruption after stimulation with VEGF or cytokines.ResultsTreatment of BRECs with GCs resulted in upregulation of tight junction mRNA (claudin‐5, occludin, ZO‐1) and protein (claudin‐5 and ZO‐1). In functional assays, only TA strengthened the barrier function by reducing endothelial permeability. Moreover, TA was able to prevent cytokine‐induced permeability in human retinal endothelial cells and VEGF‐induced expression of plasmalemma vesicle‐associated protein (PLVAP), a key player in VEGF‐induced retinal vascular leakage.ConclusionGlucocorticoids have differential effects in an experimental in vitro BRB model. TA is the most potent in improving barrier function, both at the molecular and functional levels, and TA prevents VEGF‐induced expression of PLVAP.
U2 - 10.1111/aos.13909
DO - 10.1111/aos.13909
M3 - Article
SN - 1755-375X
VL - 97
SP - 214
EP - 224
JO - Acta Ophthalmologica
JF - Acta Ophthalmologica
IS - 2
ER -
