TY - JOUR
T1 - Flt-1 intraceptors inhibit hypoxia-induced VEGF expression in vitro and corneal neovascularization in vivo
AU - Singhb, Nirbhai
AU - Amin, Shivan
AU - Richter, Elizabeth
AU - Rashid, Saadia
AU - Scoglietti, Vincent
AU - Jani, Pooja D.
AU - Wang, Jin
AU - Kaur, Rajwinder
AU - Ambati, Jayakrishna
AU - Dong, Zheng
AU - Ambati, Balamurali K.
PY - 2005
Y1 - 2005
N2 - PURPOSE. To determine whether subunits of VEGF receptor-1 coupled with an endoplasmic reticulum retention signal can block hypoxia-induced upregulation of VEGF secretion in corneal epithelial cells and block murine corneal angiogenesis induced by corneal injury. METHODS. Human corneal epithelial cells, transfected with plasmids encoding Flt23K or Flt24K (the VEGF-binding domains of the Flt-1 receptor coupled with the endoplasmic reticulum retention peptide KDEL), were subjected 2 days after transfection to 5% hypoxia for 24 hours. Supernatant was sampled at 24 hours and assayed for VEGF by ELISA. For in vivo models, mouse corneas underwent intrastromal injections of plasmids encoding Flt23K or Flt24K, and 2 days later, sustained injury induced by topical NaOH and mechanical scraping. Corneas were assessed 2 days later for VEGF ELISA and leukocyte counting or 1 week later for quantification of neovascularization. RESULTS. Hypoxia induced VEGF by human corneal epithelial cells was sequestered by both Flt23K and Flt24K; Flt-1 23K suppressed VEGF secretion as well. Intrastromal delivery of plasmid Flt23K suppressed VEGF by 40.4% (P = 0.009), leukocytes by 49.4% (P < 0.001), and neovascularization by 66.8% (P = 0.001). Flt24K suppressed VEGF expression by 30.8% (P = 0.042), leukocytes by 25.8% (P < 0.001), and neovascularization by 49.5% (P = 0.015). CONCLUSIONS. Flt-1 intraceptors, which are endoplasmic reticulum retention signal-coupled VEGF receptors, significantly suppress hypoxia-induced VEGF secretion by corneal epithelial cells in vitro. In vivo, delivery of naked plasmids expressing these intraceptors inhibits injury-induced upregulation of VEGF, leukocyte infiltration, and corneal neovascularization.
AB - PURPOSE. To determine whether subunits of VEGF receptor-1 coupled with an endoplasmic reticulum retention signal can block hypoxia-induced upregulation of VEGF secretion in corneal epithelial cells and block murine corneal angiogenesis induced by corneal injury. METHODS. Human corneal epithelial cells, transfected with plasmids encoding Flt23K or Flt24K (the VEGF-binding domains of the Flt-1 receptor coupled with the endoplasmic reticulum retention peptide KDEL), were subjected 2 days after transfection to 5% hypoxia for 24 hours. Supernatant was sampled at 24 hours and assayed for VEGF by ELISA. For in vivo models, mouse corneas underwent intrastromal injections of plasmids encoding Flt23K or Flt24K, and 2 days later, sustained injury induced by topical NaOH and mechanical scraping. Corneas were assessed 2 days later for VEGF ELISA and leukocyte counting or 1 week later for quantification of neovascularization. RESULTS. Hypoxia induced VEGF by human corneal epithelial cells was sequestered by both Flt23K and Flt24K; Flt-1 23K suppressed VEGF secretion as well. Intrastromal delivery of plasmid Flt23K suppressed VEGF by 40.4% (P = 0.009), leukocytes by 49.4% (P < 0.001), and neovascularization by 66.8% (P = 0.001). Flt24K suppressed VEGF expression by 30.8% (P = 0.042), leukocytes by 25.8% (P < 0.001), and neovascularization by 49.5% (P = 0.015). CONCLUSIONS. Flt-1 intraceptors, which are endoplasmic reticulum retention signal-coupled VEGF receptors, significantly suppress hypoxia-induced VEGF secretion by corneal epithelial cells in vitro. In vivo, delivery of naked plasmids expressing these intraceptors inhibits injury-induced upregulation of VEGF, leukocyte infiltration, and corneal neovascularization.
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U2 - 10.1167/iovs.04-1172
DO - 10.1167/iovs.04-1172
M3 - Article
C2 - 15851564
AN - SCOPUS:20444482034
SN - 0146-0404
VL - 46
SP - 1647
EP - 1652
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
IS - 5
ER -