TY - JOUR
T1 - Role of nonproteolytically activated prorenin in pathologic, but not physiologic, retinal neovascularization
AU - Satofuka, Shingo
AU - Ichihara, Atsuhiro
AU - Nagai, Norihiro
AU - Koto, Takashi
AU - Shinoda, Hajime
AU - Noda, Kousuke
AU - Ozawa, Yoko
AU - Inoue, Makoto
AU - Tsubota, Kazuo
AU - Itoh, Hiroshi
AU - Oike, Yuichi
AU - Ishida, Susumu
PY - 2007/1
Y1 - 2007/1
N2 - PURPOSE. Recently, it was revealed that the inhibition of nonproteolytic activation of prorenin led to significant suppression of ocular inflammation in endotoxin-induced uveitis. The purpose of the present study was to investigate whether nonproteolytically activated prorenin plays a role in ischemia-induced retinal neovascularization. METHODS. C57BL/6 neonatal mice were reared in an 80% concentration of oxygen from postnatal (P) day 7 to P12, followed by room-air breathing to P17 to induce ischemia-initiated retinal neovascularization. Tissue localization of activated prorenin and prorenin receptor was examined by immunohistochemistry. Animals received intraperitoneal injections of handle-region peptide (HRP), a decoy peptide corresponding to the handle region of prorenin, which inhibits prorenin receptor-mediated upregulation of the renin-angiotensin system (RAS). A concanavalin A lectin perfusion-labeling technique was used to evaluate the areas of physiologic and pathologic retinal new vessels and the number of leukocytes adhering to the vasculature. Retinal mRNA expression and protein levels of intercellular adhesion molecule (ICAM)-1, vascular endothelial growth factor (VEGF), VEGF receptor (VEGFR)-1, and VEGFR-2 were examined by RT-PCR and ELISA. RESULTS. Retinal vessels in ischemic retinopathy eyes were positive for activated prorenin and prorenin receptor. Pathologic, but not physiologic, retinal neovascularization was significantly attenuated in HRP-treated mice compared with vehicle- or control peptide-treated animals. The number of adherent leukocytes was also significantly reduced. Retinal mRNA expression and protein levels of ICAM-1, VEGF, VEGFR-1, and VEGFR-2 in ischemic retinopathy were also significantly suppressed by the application of HRP. CONCLUSIONS. The present findings suggest that nonproteolytic activation of prorenin selectively promotes pathologic, but not physiologic, retinal neovascularization through the inflammatory processes related to pathologic neovascularization.
AB - PURPOSE. Recently, it was revealed that the inhibition of nonproteolytic activation of prorenin led to significant suppression of ocular inflammation in endotoxin-induced uveitis. The purpose of the present study was to investigate whether nonproteolytically activated prorenin plays a role in ischemia-induced retinal neovascularization. METHODS. C57BL/6 neonatal mice were reared in an 80% concentration of oxygen from postnatal (P) day 7 to P12, followed by room-air breathing to P17 to induce ischemia-initiated retinal neovascularization. Tissue localization of activated prorenin and prorenin receptor was examined by immunohistochemistry. Animals received intraperitoneal injections of handle-region peptide (HRP), a decoy peptide corresponding to the handle region of prorenin, which inhibits prorenin receptor-mediated upregulation of the renin-angiotensin system (RAS). A concanavalin A lectin perfusion-labeling technique was used to evaluate the areas of physiologic and pathologic retinal new vessels and the number of leukocytes adhering to the vasculature. Retinal mRNA expression and protein levels of intercellular adhesion molecule (ICAM)-1, vascular endothelial growth factor (VEGF), VEGF receptor (VEGFR)-1, and VEGFR-2 were examined by RT-PCR and ELISA. RESULTS. Retinal vessels in ischemic retinopathy eyes were positive for activated prorenin and prorenin receptor. Pathologic, but not physiologic, retinal neovascularization was significantly attenuated in HRP-treated mice compared with vehicle- or control peptide-treated animals. The number of adherent leukocytes was also significantly reduced. Retinal mRNA expression and protein levels of ICAM-1, VEGF, VEGFR-1, and VEGFR-2 in ischemic retinopathy were also significantly suppressed by the application of HRP. CONCLUSIONS. The present findings suggest that nonproteolytic activation of prorenin selectively promotes pathologic, but not physiologic, retinal neovascularization through the inflammatory processes related to pathologic neovascularization.
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U2 - 10.1167/iovs.06-0534
DO - 10.1167/iovs.06-0534
M3 - Article
C2 - 17197563
AN - SCOPUS:33846902147
SN - 0146-0404
VL - 48
SP - 422
EP - 429
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
IS - 1
ER -