Background JAK/ signal transducer and activator of transcription 3 (STAT3) signal pathway plays a critical role during the sclera remodeling of experimental myopia.As a tyrosine kinase inhibitor,AG490 can inhibit the activation of this pathway.But whether AG490 plays a role in delaying the development of myopia is not completely clear.Objective This study was to investigate the inhibition of AG490 to activation of STAT3 signaling pathway and the sequential arresting effect on the sclera remodeling in form-deprived myopia (FDM) models.Methods Forty guinea pigs were randomly divided into the normal control group,model control group,PBS control group and AG490 treatment group.FDM models were established by the occlusion of the right eyes of guinea pigs for consecutive 4 weeks using translucent goggles in the model control group,PBS control group and AG490 treated group,and 25 μl PBS or AG490 were respectively injected into vitreous since the first day of modeling in two-day interval till the fourth week in the PBS control group and AG490 treated group.Refractive state and axial length were examined with retinoscopy and A-scan ultrasonography before and 4 weeks after experiment.The experimental eyes were extracted in the fourth week,and the expressions of scleral STAT3,p-STAT3,metal matrix proteinase-2 (MMP-2) proteins and STAT3 mRNA,MMP-2 mRNA were detected by immunocytochemstry and semi-quantitative reverse transcription PCR (RT-PCR) respectively.The use and care of experimental animals followed ARVO.Results Compared to the normal control group,the negative refraction power and axial length were significantly increased in the model control group,PBS control group and AG490 treated group,and the axial length in the AG490 treated group was smaller than those in the model control group and PBS control group,showing significant differences among the 4 groups (refraction:F =89.063,P =0.000;axial length:F =96.145,P =0.000).The expressions of STAT3,MMP-2 and p-STAT3 in scleral tissue were weaker in the normal control group.The expressional values (A values) of STAT3,p-STAT3 and M MP-2 were 0.064 ± 0.016,0.019 ± 0.002 and 0.155 ± 0.052 in the AG490 treated group,which were lower than 0.129±0.008,0.071 ±0.021,0.425 ±0.004 of the model control group and 0.130±0.004,0.069±0.002,0.421 ±0.042 of the PBS control group (STAT3:t =4.641,9.364,both at P＜0.01;p-STAT3:t =4.638,4.488,both at P＜ 0.05;MMP-2:t =9.123,9.029,both at P ＜ 0.05),however,these expressions were still higher than those of the normal control group (t =2.674,2.251,2.682,all at P ＜0.05).The expressional levels (A values) of STAT3 mRNA and MMP-2 mRNA in the AG490 treated group were 0.295±0.032 and 0.569±0.019,which were significantly lower than 0.547±0.015 and 0.782±0.051 in the model group as well as 0.544±0.015 and 0.779±0.048 in the PBS control group (STAT3 mRNA:t =10.115,11.703,both at P＜0.01;MMP-2 mRNA:t =9.218,9.494,both at P＜0.01).The expressional levels (A values) of STAT3 mRNA and MMP-2 mRNA in the AG490 treated group were still higher than those in the normal control group (t=2.576,3.565,both at P＜0.05).Conclusions AG490 can ultimately inhibit the development of axial myopia by arresting the activation of STAT3 signaling pathway in the FDM eyes and further regulating the expression of MMP-2 in sclera and delaying the remodeling of sclera.

Background Studies showed that some members of matrix metalloproteinases (MMPs) play an important role in the pathogenesis of diabetic retinopathy (DR).However,whether MMPs inhibitor can deter blood retinal barrier (BRB) from damage is below understood.Objective This study was to investigate the effects of GM6001,a MMPs inhibitor,on BRB permeability.Methods Twenty-four adult clean SD rats were randomized to the control group,diabetic group and diabetes+GM6001 group according to randomized number table.Diabetic models were induced by the intraperitoneal injection of streptozotocin in the rats of the diabetic group and the diabetes + GM6001 group,and equal volume of citrate buffer was used in the same way in the rats of the control group.GM6001 10 μ1 (100 μ mol/L) was intravitreously injected in the third and fourteenth day after modeling in the diabetes+ GM6001 group,and equal volume of normal saline solution was injected in the same way in the control group and the diabetic group.The rats were sacrificed and eyeballs were extracted 1 month after injection,and the relative expressions of MMP-2 mRNA and MMP-9 mRNA in rat retinas were detected by reverse transcription PCR (RT-PCR).Evens blue (EB) was infused via the right jugular vein,and paraformaldehyde solution 1％ was then infused via left ventricle at the perfusion pressure 120 mmHg.The eyeballs were extracted 2 minutes later,and the leakage of EB in rat retinas was examined.Results RT-PCR electrophoresis exhibited the response bands of MMP-2 mRNA,and MMP-9 mRNA and GAPDH,with the gene size of 436,536 and 484 bp,respectively.The difference of the MMP2 mRNA and MMP-9 mRNA was statisticaly significant (F =20.336,P =0.000 ; F =8.742,P =0.002) ; and the relative expressions of MMP-2 mRNA and MMP-9 mRNA were significantly higher in the diabetic group and diabetes +GM6001 group than those in the control group (all at P＜0.01),and the relative expressions of MMP-2 mRNA and MMP-9 mRNA in the diabetes+GM6001 group was significantly reduced in comparison with the diabetic group(both P=0.01,P=0.02).The standardized EB content in the retinas of the control group,diabetic group and diabetes+ GM6001 group was (12.60±3.50) ng/mg,(26.52±7.14) ng/mg and (17.55±2.65) ng/mg,showing a significant difference (F=17.032,P＜0.01),and EB content in rat retinas in the diabetic group was higher than that in the control group (P=0.003),and that in the diabetes+GM6001 group was lower in comparison with the diabetic group (P=0.020).Conclusions Intravitreal injection of GM6001 can down-regulate the expression of MMP-2 mRNA and MMP-9 mRNA in diabetic rats and therefore protect BRB.

Objective To investigate the expression of microRNA-34a (miR-34a) and silent information regulator 1 (SIRT1) in human lens epithelial cells under H2O2-induced oxidative stress.Methods Different concentrations of H2O2 (0 μmol · L-1,100 μ mol· L-1,200 μmol · L-1,300 μmol · L-1,and 400 μmol · L-1) were used to stimulate SRA01/04 cells for 24 hours.Cell viability was measured using cell counting kit-8 (CCK-8) assay.Cell apoptosis was detected by flow cytometry.Expression levels of miR-34a/SIRT1 were measured by RT-PCR.Results CCK-8 assay showed that a certain concentration range of H2O2 had a proliferation inhibition on SRA01/04 cells.There was a dose response relationship between 100 μmol · L-1 and 400 μmol · L-1.Compared with 0 μmol · L-1 H2O2 group,the difference was statistically significant (all P ＜ 0.01).According to flow cytometry results,apoptotic rate of SRA01/04 cells in control group and H2O2(100-300 μmol · L-1) groups were (6.1 ± 1.2)％,(26.3 ± 1.8)％,(32.5 ± 2.2) ％,and (64.7 ± 5.3) ％.Compared with 0 μmol · L-1 H2 O2 group,the differences were statistically significant (all P ＜ 0.01).RT-PCR test results showed that the expression of miR-34a increased significantly in a dose-dependent manner after the SRA01/04 cells treated with different concentrations of H2O2,while SIRT1 expression level was decreased,there were significant differences compared with control group (all P ＜ 0.001).Conclusion There is a significantly increase of miR-34a and decrease of SIRT1 in human lens epithelial cells under the oxidative stress of a certain concentration of H2O2.Down-regulated expression of miR-34a can increase the survival rate of human lens epithelial cells under H2O2-induced oxidative stress.

Objective To observe the effect of panretinal photocoagulation (PRP) on the expression of cyclooxygenase-2 (COX-2),vascular endothelial cell growth factor (VEGF) in epiretinal membrane of proliferative diabetic retinopathy (PDR).Methods A total of 35 patients (35 eyes) with PDR and underwent plana vitrectomy were enrolled in this study.The patients were divided into non-PRP group (19 patients,19 eyes) and PRP group (16 patients,16 eyes) depends on if they had received PRP before surgery.The epiretinal membranes stripped during operation were collected for pathological examination.The histopathological features was observed by haematoxylin and eosin stain.The expression of CD34,COX-2 and VEGF,and microvessel density (MVD) were measured by immunohistochemistry method.Results Many new dispersed capillary blood vessels were found in the thick epiretinal membranes of nonPRP group,while scattered small blood vessels were found in the relatively thin epiretinal membranes of PRP group.MVD value was (7.42± 1.39) in the non-PRP group and (4.56± 1.22) in the PRP group,which was lower than the non-PRP group (t=6.41,P＜0.01).The expression of CD34,COX-2 and VEGF in the tissues of epiretinal membrane in PRP group were obviously lower than the non-PRP group (t=6.147,5.944,7.445;P＜0.01).Conclusion PRP can effectively inhibit the expression of COX-2 and VEGF in epiretinal membrane of PRP patients.

Objective To investigate the nature of the suprachoroidal fluid by detecting the concentration of total protein (TP), lactate dehydrogenase (LDH), albumin (ALB), total cholesterol (CHOL), total bilirubin (TBIL) in suprachoroidal liquid of patients who have rhegmatogenous retinal detachment with choroid detachment (RRDCD). Methods Eighteen RRDCD patients (18 eyes) who underwent vitrectomy were enrolled in this study. There were 10 males (10 eyes) and 8 females (8 eyes), 8 right eyes and 10 left eyes. There were 8 patients with age of ≤55 years, 10 patients with age of >55 years. There were 7 patients with duration of≤30 days, 11 patients with duration of >30 days. There were 7 eyes with diopters of ≥-6.0 D, 11 eyes with diopters of <-6.0 D. There were 11 eyes with class C proliferative vitreoretinopathy (PVR), 7 eyes with class D PVR. Suprachoroidal fluid samples were collected from all the patients, and took preoperative serum samples as RRDCD group. Ten serum samples of normal people were set as control group. The concentration of TP, LDH, ALB, CHOL, TBIL in all the subjects were measured. The properties of the suprachoroidal fluid were identified by Light standard and concentration standard of ALB, CHOL, TBIL. Results There was no difference on the concentration of TP, LDH, ALB, CHOL, TBIL from suprachoroidal fluid samples in the patients with different age, sex, eyes, diopter, PVR grade (P>0.05). There was no difference on the concentration of TP, LDH, ALB, CHOL, TBIL from preoperative serum samples in the patients between RRDCD group and control group (P>0.05). There was no difference on the concentration of ALB and CHOL from suprachoroidal fluid samples and preoperative serum samples in the RRDCD patients (P>0.05), but there were significant differences on the concentration of TP, LDH, TBIL (P<0.05). According to the Light standard, there were 17 cases of exudates and 1 case of transudate. According to the concentration standard of ALB, CHOL and TBIL, there were 14, 18, and 16 cases of exudates, and 4, 0, and 2 cases of transudate, respectively. There was no difference on the identification result of Light standard and concentration standard of ALB, CHOL, TBIL (χ2=2.090, 1.029, 0.364;P>0.05). Conclusion The suprachoroidal fluid of RRDCD patients composed of TP, LDH, CHOL and TBIL. The suprachoroidal fluid is more likely to be exudate.