ABSTRACT
Objective To investigate the effects of bradykinin (BK) on the proliferation of rabbit corneal endothehal ceils (RCECs) and the expression of tight junction-related proteins zonula occludens-1 (ZO-1) and zonula occludens-1-associated nucleic-acid-binding protein (ZONAB),and to explore the underlying mechanisms of BK on cell proliferation in corneal endothelium.Methods RCECs at logarithmic growth phase were treated with different concentrations of BK (0.01,0.1,1,10 μmol · L-1) BK group,with the controls left untreated.Morphological changes of cells in each group were examined under phase-contrast microscope,and MTT assays were used to detect cell proliferation at 24 h,48 h,72 h,96 h after BK treatment.And,at 72 h,the expression levels of ZO-1 and ZONAB protein were determined by Western blot.Results After 72 h of treatment,the cells in each group were fused into pieces and closely linked into a monolayer;but after 96 h,the growth of the cells was restricted,with the intercellular space become larger and the cells exfoliated.Compared with the control group,BK induced a significant increase of absorbance value and cell viability,and the differences were statistically significant (all P ＜ 0.001),and the promoting effects showed a concentration-dependent manner,and 1 μmol · L-1 BK demonstrated the strongest regulative effect (P ＜ 0.001).Western blot results showed that BK upregulated the expression of ZO-1 and ZONAB protein in a concentration-dependent manner.Conclusion BK can stimulate the proliferation of RCECs in a time-and concentration-dependent manner,and the mechanisms are probably associated with ZO-1/ZONAB-mediated signaling pathway.
ABSTRACT
Idiopathic macular hole is a full - thickness defect of retinal tissue involving the anatomic fovea and affecting central visual acuity and quality of life in elder patients. Recent evidence showed that the alterations of choroidal blood flow and choroidal thickness are associated with the formation of macular holes. Enhanced depth imaging spectral-domain optical coherence tomography (EDI SD-OCT) enables in vivo measurement of choroidal thickness and may provide new insight into the understanding of pathogenesis of idiopathic macular hole. In this article, we reviewed current studies on the relationship between choroidal thickness measured by optical coherence tomography and the pathogenesis of idiopathic macular hole.
ABSTRACT
Background Optic neuropathy is one of the diabetic eye complications.Rosiglitazone,a peroxisome proliferator activated receptor γ(PPARγ) agonist,plays a very important role in arresting the pathogenesis and development of diabetes.However,the role of PPARγ in diabetic optic neuropathy is unclear.Objective This study was to investigate the protective effect of rosiglitazone against diabetic optic neuropathy and its mechanism.Methods Male Sprague-Dawley rats were randomly divided into the control group,diabetic group and rosiglitazone group,with 10 rats for each group.Diabetic models were induced by injecting 50 mg/kg of streptozotocin via the caudal vein,and rosiglitazone(5 ng/[kg· d])was used in the rats of the rosiglitazone group by intragastric administration every day for four weeks.At the end of the experiment,the fasting blood sugar(FBS) was tested in all the animals.The level of vascular endothelial growth factor(VEGF) in the blood plasma was detected by ELISA.Optical neural tissues were obtained from the rats of each group,and Lauck fast Blue myelin stain was used to examine the morphology of the optical myelin.The expression of neural cell adhesion molecule (NCAM) mRNA and protein in the optic nerve was detected by real time PCR and Western blot,respectively.Results The levels of FBS,blood plasma VEGF,NCAM mRNA and protein in the optic nerve were significantly different among the control group,diabetic model group and the rosiglitazone group after the administration of 5 nmg/(kg · d) rosiglitazone for 4 weeks (F =6.12,P＜0.01 ; F =5.14,P＜0.05 ; F =4.75,P＜0.05 ; F =4.87,P＜0.05).Compared with the control group,the level of FBS significantly increased in the diabetic model group(t =2.26,P＜O.05),and that in the rosiglitazone group significantly declined in comparison with the diabetic model group(t=2.08,P＜0.05).The optic nerve exhibited a normal morphology in the control group as revealed by the Lauck fast Blue myelin staining;however,severe demyelination of the optic nerve and proliferation of glial cells were found in the diabetic model group,and mild demyelination of the optic nerve and proliferation of glial cells were seen in the rosiglitazone group.Blood plasma VEGF was(28.76±4.21)ng/L in the control group and(134.28±11.36)ng/L in the diabetic model group,showing a significant difference between them (t=2.36,P ＜ 0.05).Compared with the model group,the blood plasma VEGF was significantly lower in the rosiglitazone group ([42.67 ± 5.83] ng/L) than that in the diabetic model group (t =2.17,P＜ 0.05).Expression of NCAM mRNA and protein in the optic nerve significantly decreased in the diabetic model group compared with the control group(t =2.21,t =2.58,both at P＜0.05);while those in the rosiglitazone group were significantly elevated in comparison with the diabetic model group(t =2.19,t =2.67,both at P＜O.05).Conclusions Rosiglitazone can protect optic nerve from damage in diabetic rats mainly by downregulating blood plasma VEGF level and upregulating NCAM expression.