Objective To explore transthyretin (TTR) effect on retinal vascular endothelial cells (hREC) under high glucose and hypoxia environment. Methods hREC and human retinal pigment epithelial cell (hRPEC) were cultured at low-glucose (LG), high glucose (HG) and hypoxia. The glucose concentration was increased from 5.5 mmol/L up to 25 mmol/L, and hypoxia was induced by 200 μmol/L CoCl2. The cells were divided into LG group, LG-hypoxia group, HG group, HG-hypoxia group according to the different cell culture environment. The growth index was detected at 0, 4, 8, 16, 24, 36, 48, 60, 72 hours after cultured. Furthermore, hREC and hRPEC were also cultured with additional TTR (4 μmol/L), respectively. Then transwell co-culture system was employed to reveal the effects of hRPEC on the growth of hREC. Results At 72 hours after cultured, the growth index of hREC and hRPEC in LG group were increased as compared with LG-hypoxia group and HG group (hREC: F=17.098, 22.970; P < 0.05. hRPEC: F=45.442, 9.011; P < 0.05); the growth index of hREC and hRPEC were decreased in HG group and HG-hypoxia group (hREC: F=146.184, P < 0.05；hRPEC: F=27.907, P < 0.05). Additionally, hREC could be significantly repressed by added TTR during culture with high concentration of glucose (F=161.430, 24.106; P < 0.05). hREC could be significantly increased by added TTR during culture with low concentration of glucose (F=200.486, 48.662; P < 0.05). In co-culture process, hRPEC revealed inhibition activity against hREC under both natural and abnormal environment (LG group: F=15.711, P < 0.05; LG-hypoxia group: F=45.659, P < 0.05; HG group: F=7.857, P < 0.05; HG-hypoxia group: F=6.348, P < 0.05). Conclusion Under high glucose and hypoxia environment, the growth of hREC from neovascular could be inhibited by TTR.
ObjectiveTo observe the changes in open probability and protein expression of large conductance Ca2+-activated K+ (BK) channel in retinal vascular smooth muscle cells (RVSMCs) of diabetic rats. MethodsStreptozotocin (STZ)-induced rat diabetic animal model was established by STZ injection intraperitoneally.RVSMCs were isolated by enzyme digestion. The BK currents in control and diabetic groups were recorded by patch clamp technique in single channel configuration. BK channel protein expression in control and diabetic group were measured by Western blot. ResultsCompared with control group, the NP0 of BK channels in diabetic group were significantly increased (t=4.260, P < 0.05). Compared with control group, there was no significant difference inα-subunit protein expression in diabetic group in RVSMCs (t=10.126, P > 0.05); however, β1-subunit protein expression was remarkably increased in diabetic group (t=5.146, P < 0.05). ConclusionThe NP0 of BK channels andβ1-subunit protein expression are increased in RVSMCs of diabetic rats.
ObjectiveTo explore the effects of transthyretin (TTR) on biological behavior of retinal microvascular epithelial cell (RMVEC). MethodsRMVEC was cultured in medium with 0 μmol/L and 4 μmol/L TTR. The proliferation, migration and healing abilities (0, 24, 48 hours) of RMVEC with different concentrations of TTR were measured by methyl thiazol tetrazolium (MTT) assay, transwell assay and scarification test. ResultsMTT assay shows that RMVEC with the concentrations of 4 μmol/L TTR [absorbance (A) value=0.17±0.02] glows faster than with the concentrations of 0 μmol/L TTR (A value=0.40±0.03), the difference was statistically significant (t=15.47, P=0.000 1). The transwell assay shows RMVEC with the concentration of 4 μmol/L TTR [(140±7) cells] migrants faster than RMVEC with the concentration of 0 μmol/L TTR [(227±14) cells], the difference was statistically significant (t=5.44, P=0.000 6). The scarification test shows that the RMVEC with the concentration of 4 μmol/L TTR [(134.4±45.4) μm] heals faster than the RMVEC with the concentration of 0 μmol/L TTR [(330.0±23.1) μm], the difference was statistically significant (t=8.25, P<0.01). The cells in 48 hours and 4 μmol/L group were healed completely, but not healed in 0 μmol/L group. ConclusionTTR can promote the proliferation, migration and healing abilities of RMVEC.