RESUMO
AIM: To investigate the relationships between the changes of heat shock protein 27 antibody (anti-HSP27) in serum/cerebrospinal fluid (CSF), intraocular pressure (IOP), retinal ganglion cell (RGC) apoptosis in a rat glaucoma model and disclose the underlying pathogenesis of glaucoma. METHODS: A total of 115 Wistar rats were randomly divided into 4 groups. Group 1 was the ocular hypertension group by condensing 3 episcleral & limbal veins or episcleral area of right eye (HP group, n=25) and sham operation group with conjunctiva incision without coagulation (n=25). Group 2: HSP27 or dose-matched PBS was injected into the vitreous (V-HSP27 group, n=15; V-PBS group, n=15). Group 3: HSP27 and complete Freund's adjuvant or dose-matched PBS was injected subcutaneously into the hind limb accompanied intraperitoneal injection of pertussis toxin [sensitized group (I-HSP27 group), n=15; I-PBS group, n=15)]. Group 4 was normal group without any treatment (n=5). IOPs of the rats were measured before, day 3, weeks 1, 2, 4, 6, and 8 after treatment. Paraffin-embedded sections were prepared for HE staining and RGCs apoptosis were detected by TUNEL. Anti-HSP27 level in serum and CSF were examined by ELISA. RESULTS: IOPs were elevated significantly in HP and V-HSP27, V-PBS groups (P<0.01) and positively related to anti-HSP27 levels in serum and CSFs. Anti-HSP27 levels in serum and CSF were elevated significantly in I-HSP27 group compared to other groups (P<0.05). However, the IOPs did not show any relationship with the high-level anti-HSP27 in serum and CSFs. RGC apoptosis were all elevated significantly in the HP, V-HSP27, V-PBS and I-HSP27 groups and also positively relative with anti-HSP27 level in serum and CSFs except that high-level of anti-HSP27 in the serum of I-HSP group. CONCLUSION: The increases of anti-HSP27 levels in serum and CSFs both promote IOP escalation and the increase of RGC apoptosis in retina when anti-HSP27 is at low level. The case of high-level anti-HSP27 is opposite and shows protective function in preventing IOP increase and RGC apoptosis.
RESUMO
OBJECTIVE: This study aims to explore the possible role of fenofibrate in inhibiting choroidal neovascularization (CNV) in Brown Norway (BN) rats. METHODS: BN rats underwent binocular retinal laser photocoagulation to induce CNV. On day one, fenofibrate was injected into the vitreous cavity of rats in the control and experimental groups. Fundus fluorescein angiography (FFA), isolectin B4-FITC staining, immunofluorescence staining, qRT-PCR and western blot were performed at 1, 2, 3 and 4 weeks to observe the morphological changes of CNV and the expression of the vascular endothelial growth factor C (VEGF-C) and the vascular endothelial growth factor receptor-3 (VEGFR-3). RESULTS: CNV with the spontaneous gradual regression and scarring phenomenon appeared in BN rats. In neovascularization, VEGF-C was mainly distributed in the ganglion cell layer, while VEGFR-3 was mainly expressed in the choroid. In the control group, choroidal VEGF-C initially increased, and subsequently decreased, while VEGFR-3 level maintained a constant level after the decrease. Both had a decreasing expression in the retina. The early formation of CNV was significantly weakened in the experimental group, but there was no difference in the later period. VEGF-C and VEGFR-3 expression in the choroid and retina were lower than in the control group. Furthermore, VEGFR-3 protein was not expressed in the retina. However, this gradually increased in the early period and declined in the terminal stage in the choroid. CONCLUSION: VEGF-C and VEGFR-3 participated in the laser-induced CNV formation in BN rats. Fenofibrate could inhibit CNV formation.
