Since anti-vascular endothelial growth factor (VEGF) therapy has recently become the first-line treatment of wet age related macular degeneration in China, as well as retinopathy of prematurity, neovascular glaucoma and macular edema secondary to diabetic retinopathy or retinal vein occlusion in other countries. It is worth thinking about that how to perform anti-VEGF treatment properly to benefit more patients. We reviewed the fields of clinical researches to explore the best role of anti-VEGF treatment in prevention and treatment of retinal disease in future.
Retinal neuronal cells are crucial in the formation of vision. Injury or death of these cells may lead to irreversible damage to visual function due to their low regenerative capacity. The P2X7 receptor is a trimeric adenosine triphosphate (ATP)-gated cation channel. Recent studies have shown that P2X7 receptor plays a role in retinal neuronal death. In a series of animal models, when exposed to conditions of hypoxia or ischemia, elevated ocular pressure, trauma and exogenous agonists, P2X7 receptor activated by extracellular ATP can cause death of retinal neuronal cells such as retinal ganglion cells and photoreceptor cells through direct or indirect pathways. Blocking the expression and function of P2X7 receptor by its specific antagonist and gene knocking-out, the loss of retinal neuronal cells is significantly attenuated. P2X7 receptor may become a potential novel neuroprotective target for diseases related to the loss of retinal neurons.
The therapeutic response of anti-vascular endothelial growth factor (VEGF) differs among individuals. According to the changes of central retinal thickness, intraretinal fluid, subretinal fluid, best corrected visual acuity and other morphological or functional manifestations after treatment, the performance of the treated eyes can be classified as optimal response, poor response and non-response. A variety of factors could account for poor or non-response to anti-VEGF, such as genomic polymorphism and specific genomic risk alleles, lesion characteristics, vitreous and macular structural abnormalities, resistance to anti-VEGF drug, and the role of pericytes and others. The common counter measures include increasing the dosage, shortening the injection interval and replacing with another alternative drug, inhibition of pericytes, relieving vitreomacular anatomical abnormalities. It is still worthy of further exploration that how to assess individual reasons for non-response, so that we can give proper treatment to reduce the excessive use of anti-VEGF drugs and improve the clinical management of ocular neovascularization diseases.
Thinning and atrophy of sclerotic tissues play an important role in the development of high myopia. High myopic eyes had the thickest sclera at the posterior pole and the thinnest sclera at the equator. Most clinical studies found that scleral thickness was negatively correlative with the axial length. Patients complicated with posterior staphyloma had even thinner sclera, and its height was negatively related with the scleral thickness. At present, the main measurement methods for scleral thickness of high myopic eyes include histological measurement, enhanced depth imaging optical coherence tomography (OCT), and swept-source OCT. Following the development of OCT technique, it gradually becomes feasible to carry out studies on sclera thickness in mildly and moderately myopic populations, which is helpful to illuminate the mechanism of action of sclera on the onset and progression of high myopia.
Objective To observe the influences of uncoupling protein 2 (UCP-2) rs660339 variants transfection on cell proliferation and apoptosis of human umbilical vein endothelial cell (HUVEC). Methods Two UCP-2 green fluorescent protein (GFP) lentivirus constructs were created with the rs660339 locus carried C or T (UCP-2C or UCP-2T), respectively. HUVEC were cultured after lentiviral infection of UCP-2C or UCP-2T. The expression of UCP-2C or UCP-2T was detected with real time polymerase chain reaction. Cell proliferation and cell apoptosis were compared among negative control (NC) group, UCP-2T group and UCP-2C group using CCK-8 cell viability and flow cytometry. Western blot and immunostaining were employed to examine the expression of Bcl-2 gene. Results The lentivirus constructs were successfully created. ＞80% of the transfected cells were found to express GFP under fluorescent microscope. The mRNA levels of UCP-2 gene were significantly increased (F=29.183,P=0.001) in the UCP-2T group and UCP-2C group. The CCK-8 assay revealed that on day two (F=15.970,P=0.004), day three (F=16.738,P=0.004), day four (F=5.414,P=0.045) post-infection, UCP-2T and UCP-2C group showed significantly greater proliferation than the NC cells. The apoptotic rate in the UCP-2T and UCP-2C group was significantly lower than NC group (F=277.138,P=0.000), and the apoptotic rate of UCP-2T was significantly lower than that of UCP-2C (P=0.003). The protein levels of Bcl-2 in the UCP-2T and UCP-2C group were significantly greater than that in the NC group (F=425.679,P=0.000), and the Bcl-2 expression of UCP-2T was greater than that of UCP-2C (P=0.002). The Bcl-2 density in the UCP-2T and UCP-2C group were greater than that in the NC group (F=11.827,P=0.008), while there was no difference between UCP-2T and UCP-2C group (P=0.404). Conclusion The variants of UCP-2 rs660339 may influence HUVEC proliferation and apoptosis, and UCP-2T showed a stronger effect of inhibiting apoptosis than UCP-2C.