Sensitized heat shock protein 27 induces retinal ganglion cells apoptosis in rat glaucoma model.

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.

MicroRNA-126: a promising novel biomarker in peripheral blood for diabetic retinopathy.

AIM: To investigate the content of serum microRNA-126 (miR-126) and its role in screening retinal endothelial injury and early diagnosis of proliferative diabetic retinopathy. METHODS: The study included 184 serum samples, 59 samples from healthy individuals, 44 samples from diabetes mellitus (DM) patients without diabetic retinopathy (NDR), 42 from non-proliferative diabetic retinopathy (NPDR) patients and 39 samples from proliferative diabetic retinopathy (PDR) patients. The expression of miR-126 was evaluated using a real-time quantitative polymerase chain reaction. RESULTS: The serum content of miR-126 declined as the damage degree in the retina. There was significant difference between the two retinopathy groups (P<0.001). No difference was observed in miR-126 content between healthy individuals and NDR patients (P>0.05). Receiver operating characteristic curve (ROC) analyses indicated that serum miR-126 had significant diagnostic value for PDR. It yielded an area under the curve (AUC) of ROC of 0.976 with 81.21% sensitivity and 90.34% specificity in discriminating PDR from healthy controls, and an AUC of ROC of 0.919 with 84.75% sensitivity and 94.41% specificity in discriminating NDR and NPDR from healthy controls. When the diagnostic threshold was greater than or equal to 8.43, there was an increase in the possibility of NPDR. When the content of miR-126 was less than or equal to 5.02, the possibility of the occurrence of PDR increased. CONCLUSION: Serum miR-126 can serve as a non-invasive biomarker for screening retinal endothelial injury and early diagnosis PDR.

[Oxidative damage and photoreceptor cell apoptosis in contusion injury of the rabbit retina].

OBJECTIVE: To study the mechanism of retina injury and photoreceptor apoptosis after contusion as well as their triggering factor. METHODS: The rabbit retina was injured by a 3 J energy contusion caused by a free falling iron bar hitting the cornea. The morphologic changes of the retina were observed by light and electron microscopes. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) technique was used to assess apoptosis. The amount of the malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) in the retina were assayed and analyzed statistically. RESULTS: Apoptosis of photoreceptors was present in retina contusion caused by a 3 J energy injury. After contusion, the MDA level increased gradually. The activity of SOD increased reflectively at first, then decreased markedly 3 days after the contusion, which was parallel with the appearance of apoptotic photoreceptors. CONCLUSIONS: Apoptosis is an important mechanism of retina contusion. Free oxygen radicals are the important triggering factors for the apoptosis of photoreceptors in the retina contusion of the rabbits.

Detection and comparison of matrix metalloproteinase in primary and recurrent pterygium fibroblasts.

AIM: To detect and compare the levels of matrix metalloproteinases (MMPs) secreted by primary and recurrent human pterygium fibroblasts (HPFs). METHODS: Primary and recurrent HPFs as well as human conjunctival fibroblasts (HCF) were cultured in RPMI 1640 medium at the same conditions. The protein levels of MMP-1, MMP-3 and MMP-9 were determined by enzyme-linked immune sorbent assay (ELISA), respectively. RESULTS: 1) The protein level of MMP-1 in serum-free supernatant from cultured primary and recurrent HPFs was higher than that in normal HCFs (P<0.05); similarly, the protein level of MMP-1 in serum-free supernatant from cultured primary HPFs was higher than that in recurrent HCFs (P<0.05). 2) The protein level of MMP-3 in serum-free supernatant from cultured primary HPFs was higher than that in normal HCFs (P<0.05); meanwhile, the protein level of MMP-3 in serum-free supernatant from cultured recurrent HPFs was lower when compared with that in primary HPFs and normal HCFs (P<0.05). 3) MMP-9 was not detected in primary and recurrent HPFs in the conditioned medium. CONCLUSION: The protein levels of MMP-1 and MMP-3 in supernatant secreted by primary HPFs are different from recurrent HPFs. Different pathological mechanisms may exist between primary and recurrent pterygia.