title: Dexamethasone inhibits high glucose-, TNF-alpha-, and IL-1beta-induced secretion of inflammatory and angiogenic mediators from retinal microvascular pericytes.
abstract: OBJECTIVE
  To characterize the effects of dexamethasone in human retinal pericytes (HRMPs), monocytes (THP-1), and retinal endothelial cells (HRECs) treated with high glucose, TNF-alpha, or IL-1beta.
  
  
  METHODS
  HRMP and HREC phenotypes were verified by growth factor stimulation of intracellular calcium-ion mobilization. Glucocorticoid receptor phosphorylation was assessed with an anti-phospho-Ser(211) glucocorticoid receptor antibody. Secretion of 89 inflammatory and angiogenic proteins were compared in cells incubated with (1) normal (5 mM) or high (25 mM) D-glucose and (2) control medium, TNF-alpha (10 ng/mL), or IL-1beta (10 ng/mL), with or without dexamethasone (1 nM to 1 microM). The proteins were compared by using multianalyte profile testing.
  
  
  RESULTS
  HRMPs and HRECs expressed functional PDGFB-R and VEGFR-2, respectively. Dexamethasone induction of glucocorticoid receptor phosphorylation was dose-dependent in all cell types. High glucose increased secretion of inflammatory mediators in HRMPs, but not in HRECs. Dexamethasone dose dependently inhibited secretion of these mediators in HRMPs. For all cells, TNF-alpha and IL-1beta induced a fivefold or more increase in inflammatory and angiogenic mediators; HRMPs secreted the greatest number and level of mediators. Dexamethasone dose dependently inhibited the secretion of multiple proteins from HRMPs and THP-1 cells, but not from HRECs (IC(50) 2 nM to 1 microM).
  
  
  CONCLUSIONS
  High glucose, TNF-alpha, and IL-1beta induced an inflammatory phenotype in HRMPs, characterized by hypersecretion of inflammatory and angiogenic mediators. Dexamethasone at various potencies blocked hypersecretion of several proteins. Pericytes may be a key therapeutic target in retinal inflammatory diseases, including diabetic retinopathy. Inhibition of pathologic mediators may depend on delivering high levels ( approximately 1 microM) of glucocorticoid to the retina.
authors.affiliation: Department of Biological Sciences, Allergan Inc., 2525 Dupont Drive, Irvine, CA 92612, USA.
authors.forename: Alissar
authors.initials: A
authors.lastname: Nehmé
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Edelman
mesh_terms: D042501:Angiogenic Proteins / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D003907:Dexamethasone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D005938:Glucocorticoids / Q000494:pharmacology; D005947:Glucose / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D053583:Interleukin-1beta / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism; D020286:Pericytes / Q000187:drug effects* / Q000378:metabolism; D010766:Phosphorylation; D011965:Receptors, Glucocorticoid / Q000378:metabolism; D012171:Retinal Vessels / Q000166:cytology*; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors* / Q000494:pharmacology
chemical_list: D042501:Angiogenic Proteins; D005938:Glucocorticoids; D018836:Inflammation Mediators; D053583:Interleukin-1beta; D011965:Receptors, Glucocorticoid; D014409:Tumor Necrosis Factor-alpha; D003907:Dexamethasone; D005947:Glucose; D002118:Calcium