ObjectiveTo study the role of Rac1 in the epithelial-mesenchymal transition (EMT) process of retinal pigment epithelial cells (RPE) induced by transforming growth factorβ(TGF-β). MethodsHuman ARPE-19 cells were divided into 4 groups including control group, TGF-βgroup, TGF-β+NSC23766 group, NSC23766 group. NSC23766 was added to medium 2 hours before TGF-βtreatment to block the Rac1 receptors.α-smooth muscle actin (α-SMA) expression was measured by immunofluorescence and Western blot. Cell scratch assay, invasion assay and gel contraction experiments were used to measure cell migration, invasion, cell contraction. ResultsThe expression ofα-SM A was higher in TGF-βgroup, compared with the control group, TGF-β+NSC23766 group (F=825.314, P < 0.05). Cell scratch assay showed that the cellular gap was less in GF-βgroup, compared with the control group, TGF-β+NSC23766 group, NSC23766 group (F=177.351, P < 0.05). Cell invasion assay showed that, the number of cells pass through the fiber membrane was the same in TGF-βgroup and other 3 groups (F=0.371, P=0.055). Gel contraction assay showed that TGF-βcan promote the cellular contraction, compare to the control group, TGF-β+NSC23766 group, NSC23766 group, the difference was statistically significant (F=40.473, P < 0.05). ConclusionRac1 play a role in TGF-β-induced behavioral changes of RPE cells; NSC23766 inhibit RPE cellular behavior change by regulating Rac1 activation.
ObjectiveTo observe the effect of microincision vitrectomy assisted with intravitreaI injection of ranibizumab (IVR) in proliferative diabetic retinopathy (PDR) treatment. MethodsThis is a prospective, randomized, and comparative case series study. A total of 92 patients (92 eyes) with PDR were recruited to have microincision vitrectomy with (combined group) or without (PPV group) IVR. There are 48 eyes in the combined group and 44 eyes in the PPV group. The average operation time, iatrogenic breaks, the use of tamponade and electric coagulation, postoperative bleeding and best corrected visual acuity were comparatively analyzed among the two groups.The mean follow-up was (14.3±5.2) months. ResultsThe average operation time was (59.4±18.5) min in the combined group and (74.6±16.2) min in the PPV group. The rate of silicone oil tamponade (χ2=4.619), inert gas tamponade (χ2=4.290), electric coagulation (χ2=8.039) and iatrogenic breaks (χ2=4.330) in the combined group were significantly decreased compared with PPV group(P<0.05). The mean logMAR BCVA was 0.83±0.44 in the combined group and 1.37±0.53 in the PPV group, which significantly improved from preoperatively (t=3.257, 3.012; P<0.05). The rate of BCVA improvement in the combined group was significantly higher than that in the PPV group (t=2.972, P<0.05). The incidence of the recurrent vitreous hemorrhage was 2.1% in the combined group and 9.1% in the PPV group (χ2=6.741, P<0.05). There was no severe complication associated with surgery, such as choroidal detachment, retinal detachment and endophthal-mitis. ConclusionIVR before the microincision vitrectomy can shorten the operation time, reduce the use of electric coagulation and intraocular tamponade, and improve visual acuity for PDR patients.