Expression angiogener Faktoren durch photodynamische Therapie

Zusammenfassung

Hintergrund: Der Einfluss der photodynamischen Therapie (PDT) auf die Regulation von Angiogenesefaktoren (vascular endothelial growth factor [VEGF] und pigment epithelium derived factor [PEDF]) wird in menschlichen Augen untersucht. Methode: Augen von Patienten mit unbehandelbarem malignen Melanomen der Peripherie und Indikation zur Enukleation dienten als Studienaugen (n = 2), altersentsprechende Spenderaugen wurden als Kontrolle (n = 2) verwendet. Verteporfin-PDT mit den empfohlenen Standardparametern wurde an intakten Netzhaut- und Aderhautarealen des hinteren Pols appliziert. Nach einer Woche wurden die Behandlungsareale ophthalmologisch, Fluoreszein-(FA-) und Indocyaningrün-(ICGA-)angiographisch untersucht. Postoperativ wurden die Studienaugen lichtmikroskopisch (LM) und elektronenmikroskopisch (EM) analysiert. Eine Immunhistochemie mit spezifischen Antikörpern gegen VEGF und PEDF wurde in PDT-behandelten Arealen und unbehandelten Arealen von Studienaugen sowie in unbehandelten Arealen von Kontrollaugen durchgeführt. Ergebnisse: Alle PDT-behandelten Areale zeigten eine charakteristische chorioidale Hypofluoreszenz in der FA/ICGA. LM- und EM-histologisch zeigte sich eine selektive Schädigung der choriokapillaren Endothelzellen. Eine reproduzierbare Expression von VEGF war ausschließlich in den choriokapillaren Gefäßendothelien PDT-behandelter Areale sowie fokal in größeren Chorioideagefäßen nachweisbar. Die Aderhaut von unbehandelten Arealen der Studienaugen oder Kontrollaugen war VEGF-negativ. PEDF wurde in der Netzhaut und dem RPE aller Augen exprimiert, jedoch konnte nur in den choriokapillaren Gefäßendothelien PDT-behandelter Areale PEDF nachgewiesen werden. Schlussfolgerungen: PDT mit Verteporfin induziert nicht nur strukturelle und angiographische, sondern auch biologische Effekte in menschlichen Augen. VEGF- und PEDF-Expression in Endothelien der Chorioidea infolge PDT sind dokumentierbar und beeinflussen unmittelbar den Heilungsverlauf nach Therapie.

Abstract

Purpose: The purpose of this study was to evaluate the impact of photodynamic therapy (PDT) on the regulation of angiogenic factors such as vascular endothelial growth factor (VEGF) and pigment epithelium derived factor (PEDF) in human eyes. Methods: Eyes of patients with untreatable malignancy served as the study eyes (n = 2), age-matched donor eyes were used as controls (n = 2). Standard Verteporfin-PDT was applied to intact areas of the posterior pole. One week after PDT the eyes were examined by ophthalmoscopy as well as fluorescein (FA) and indocyanine green angiography (ICGA). After enucleation the eyes were processed for LM/EM histology. Immunolabeling using specific antibodies against VEGF and PEDF was performed in PDT-treated areas, untreated collateral areas of study eyes and untreated areas of control eyes. Results: All PDT-treated areas demonstrated a typical choroidal hypofluorescence on FA/ICGA. In LM/EM histology a selective damage of choriocapillary endothelial cells was found. VEGF expression was localized only to choriocapillary endothelial cells and focally in larger choroidal vessels of PDT-treated areas. Untreated areas of study eyes and controls were VEGF-negative. PEDF staining was observed in retinas and RPE of all eyes, but only choroidal endothelial cells of PDT-treated areas showed a PEDF-positive reactivity. Conclusion: PDT not only induces structural and angiographic, but also biological effects in human eyes. VEGF and PEDF expression can be documented in choroidal endothelial cells following PDT and could have an impact on the recovery process after treatment.

Schlüsselwörter

Photodynamische Therapie - Angiogenese - vascular endothelial growth factor

Key words

Photodynamic therapy - angiogenesis - vascular endothelias growth factor

Literatur

• 1 Aiello L P, Avery R L, Arrigg P G. Vascular endothelial growth factor in ocular fluid of patients with diabetic retinopathy and other retinal disorders.  N Engl J Med. 1994;  331 1480-1487
• 2 Amin R, Pulkin J E, Frank R N. Growth factor localization in choroidal neovascular membranes of age-related macular degeneration.  Invest Ophthalmol Vis Sci. 1994;  35 3178-3188
• 3 Bouck N. PEDF: antiangiogenic guardian of ocular function.  Trends Mol Med. 2002;  8 3158-3164
• 4 Dawson D W, Volpert O V, Gellis P. Pigment epithelium derived factor: a potent inhibitor of angiogenesis.  Science. 1999;  285 245-248
• 5 Duh E J, Yang H S, Suzuma I. Pigment epithelium derived factor suppresses ischemia-induced retinal neovascularization and VEGF-induced migration and growth.  Invest Ophthalmol Vis Sci. 2002;  43 821-829
• 6 Ferrario A, von Thiel K F, Rucker N. et al . Antiangiogenic treatment enhances photodynamic therapy responsiveness in a mouse mammary carcinoma.  Cancer Res. 2000;  60 4066-4069
• 7 Fingar V H. Vascular effects of photodynamic therapy.  J Clin Laser Med Surg. 1996;  14 323-328
• 8 Karakousis P, John S, Behling K. Localization of pigment epithelium derived factor (PEDF) in developing and adult human ocular tisssues.  Mol Vis. 2001;  7 154-163
• 9 Krammer B. Vascular effects of photodynamic therapy.  Anticancer Res. 2001;  21 4271-4277
• 10 Kvanta A, Algvere P V, Berglin L. et al . Subfoveal fibrovascular membranes in age-related macular degeneration express vascular endothelial growth factor.  Invest Ophthalmol Vis Sci. 1996;  37 1929-1934
• 11 Kwak N, Okamoto N, Wood J. et al . VEGF is a major stimulator in a model of choroidal neovascularization.  Invest Ohthalmol Vis Sci. 2000;  41 3158-3164
• 12 Lopez P F, Sippy B D, Lambert H M. et al . Transdifferentiated retinal pigment epithelial cells are immuno-reactive for vascular endothelial growth factor in surgically excised age-related macular degeneration-related choroidal neovascular membranes.  Invest Ophthalmol Vis Sci. 1996;  37 855-868
• 13 Malecaze F, Clamens S, Sinorre-Pinatel V. Detection of vascular endothelial growth factor messenger RNA and vascular endothelial growth factor-like activity in proliferative diabetic retinopathy.  Arch Ophthalmol. 1994;  112 1476-1482
• 14 Michels S, Schmidt-Erfurth U. Sequence of early vascular events following photodynamic therapy.  Invest Ophthalmol Vis Sci. 2003;  44 2147-2154
• 15 Mori K, Duh E, Gehlbach P. Pigment epithelium derived factor inhibits retinal and choroidal neovascularization.  J Cell Physiol. 2001;  188 253-263
• 16 Mori K, Gehlbach P, Yamamoto S. AAV-mediated gene transfer of pigment epithelium derived factor inhibits choroidal neovascularization.  Invest Ophthalmol Vis Sci. 2002;  43 1994-2000
• 17 Ogata N, Wang R, Jo N. Pigmentepithelium derived factor as a neuroprotective agent against ischemic retinal injury.  Curr Eye Res. 2001;  20 245-252
• 18 Plate K H, Breier G, Welch H A. et al . Vascular endothelial growth factor is a potential tumor angiogenesis factor in human gliomas in vivo.  Nature. 1992;  359 845-848
• 19 Schlötzer-Schrehardt U, Vistenz A, Naumann G OH. et al . Dose-dependent structural effects of photodynamic therapy on choroidal and retinal structures of human eyes.  Graefes Arch Cin Exp Ophthalmol. 2002;  240 748-757
• 20 Schmidt-Erfurth U, Hasan T. Mechanisms of action of photodynamic therapy with verteporfin for the treatment of age-related macular degeneration.  Surv Ophthalmol. 2000;  45 195-214
• 21 Schmidt-Erfurth U, Laqua H, Schlötzer-Schrehardt U. et al . Histopathological changes following photodynamic therapy in human eyes.  Arch Ophthalmol. 2002;  120 835-844
• 22 Schmidt-Erfurth U, Michels S. Changes in confocal indocyanine green angiography through two years following photodynamic therapy with verteporfin.  Ophthalmology. 2003;  110 1306-1314
• 23 Schmidt-Erfurth U, Michels S, Barbazetto I. et al . Photodynamic effects on choroidal neovascularization and physiological choroid.  Invest Ophthalmpl Vis Sci. 2002;  43 830-841
• 24 Schweiki D, Hin A, Soffer D. et al . Vascular endothelial growth factor induced by hypoxia may mediate hypoxia-initiated angiogenesis.  Nature. 1992;  359 843-845
• 25 Singermann L, Eye T ech Study Group. Anti-VEGF therapy for subfoveal choroidal neovascularization secondary to age-related macular degeneration: Phase 1B Results.  Invest Ophthalmol Vis Sci. 2002;  43 117
• 26 Slakter J, Singerman L. Anecortave Acetate Study Group. Subtenon’s administration of the angiostatic agent. Anecortave acetatein AMD patients with subfoveal choroidal neovascularization (CNV) - the clinical outcome.  Invest Ophthalmol Vis Sci. 2002;  43 117
• 27 Tolentino M, Miller J W, Gragoudas E. et al . Vascular endothelial growth factor is sufficient to produce iris neovascularization and neovascular glaucoma in a nonhuman primate.  Arch Ophthalmol. 1996;  114 964-970
• 28 Treatment of age-related macular degeneration with photodynamic therapy (TAP) Study Group . Photodynamic therapy of subfoveal choroidal neovascularization in age-related macular degeneration with verteporfin. One-year results of 2 randomized clinical trials - TAP Report 1.  Arch Ophthalmol. 1999;  117 1329-1345
• 29 Treatment of age-related macular degeneration with photodynamic therapy (TAP) Study Group . Photodynamic therapy of subfoveal choroidal neovascularization in age-related macular degeneration with verteporfin. Two-year results of 2 randomized clinical trials - TAP Report 2.  Arch Ophthalmol. 2001;  119 198-207
• 30 Uehara M, Inokuchi T, Sano K. et al . Expression of vascular endothelial growth factor in mouse tumours subjected to photodynamic therapy.  Eur J Cancer. 2001;  37 2111-2115
• 31 Verteporfin in Photodynamic therapy (VIP) Study group . Verteporfin therapy of subfoveal choroidal neovascularization in age-related macular degeneration: two-year results of a randomized clinical trial including lesions with occult and with no classic choroidal neovascularization - VIP Report 2.  Am J Ophthalmol. 2001;  131 541-546
• 32 Wada M, Ogata N, Otsuji T. et al . Expression of vascular endothelial growth factor and its receptor (KDR/fek-1) mRNA in experimental choroidal neovascularization.  Curr Eye Res. 1999;  18 203-213
• 33 Witmer A, Blaauwgeers H, Weich H. et al . Altered expression patterns of VEGF receptors in human diabetic retina and inexperimental VEGF-induced retinopathy in monkey.  Invest Ophthalmol Vis Sci. 2002;  43 849-857