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 effects of Krüppel like factor 4 (KLF4)on matrix metalloproteinase 9 (MMP9)ex-pression in hepatocellular carcinoma(HCC).Methods A total of 50 primary hepatocellular carcinoma samples and their correspond-ing adjacent tissues specimens were collected.The expression of KLF4 and MMP9 were detected by IHC,Western blot and qRT-PCR.After KLF4 gene was transfected into hepatocellular carcinoma cell line (HepG2 cell line),the expressions of KLF4 and MMP9 were conformed by qRT-PCR and Western blot.Migration and invasion of HepG2 cell line transfected by KLF4 were detec-ted by wound-healing assay and invasion assay.Results Compared to corresponding adjacent tissues,The expression of KLF4 was significantly lower in HCCs(P <0.05),and MMP9 expression was remarkably higher in HCCs(P <0.05).KLF4 over-expression inhibited the expression of MMP9 on the protein and mRNA levels.Wound-healing assay and invasion assay confirmed that KLF4 regulated cell invasion and migration through regulating MMP9 expression.Conclusion KLF4 showed low expression in HCCs,and MMP9 was overexpressed.Up-regulation of KLF4 could decrease the expression of MMP9 in HepG2 cell line,which inhibited inva-sion and migration.

Objective: To observe the changes of choroidal capillary flow area (CBFA) and density in patients with idiopathic macular hole (IMH) before and after surgery. Methods: A prospective clinical study. Thirty patients (60 eyes) with unilateral IMH diagnosed in Department of Ophthalmology of The Second Hospital of Hebei Medical University from February 2017 to March 2018 and 30 age-and sex- matched normal controls were included in this study. All eyes were divided into group A (30 affected eyes), group B (30 fellow eyes) and group C (30 normal eyes of controls). Among 30 eyes in group A, there were 5, 14, 11 eyes with hole in stage Ⅱ, Ⅲ, Ⅳ, respecitvely. The eyes in group A were divided into two subgroups according to the diameter of the holes: group D: hole diameter less than or equal to 500 μm (11 eyes), group E: hole diameter over than 500 μm (19 eyes). All eyes in group A underwent vitrectomy. Spectral-domain OCT was used to observe the diameter size of macular hole and the closure of the hole after vitrectomy in eyes of group A. The CBFA and blood flow density of superficial choroidal capillaries were measured by OCT angiography before and 3 months after vitrectomy in groups A, B and C. Univariate analysis of variance and t test were used for statistical analysis. Results: Before surgery, in group A, B and C, the CBFA were 2.84±0.35, 3.19±0.23, 3.26±0.24 mm², the blood flow density were (20.74±8.26)%, (35.18±5.20)%, (35.20±6.49)%, respectively. The CBFA and blood flow density in group A were significantly lower than those in group B and C (F=19.768, 45.583; P = 0.000, 0.000), but there was no significant difference between group B and C (F=19.768, 45.583; P=0.332, 0.994). The CBFA and blood flow density in group D were higher than those in group E (t=2.230, 2.202; P=0.034, 0.036). The diameter of macular hole was negatively correlated with CBFA and blood flow density (r=-0.377, -0.477; P=0.044, 0.009). Three months after surgery, the macular holes in group A were closed; CBFA and blood flow density in macular area were significantly higher than before surgery (t=-4.126, -4.912; P=0.000, 0.000). Conclusions CBFA and blood flow density decreased in the macular area of IMH. CBFA and blood flow density can be recovered after vitrectomy.