Aquaporin 5 maintains lens transparency by regulating the lysosomal pathway using circRNA.

The lens is transparent, non-vascular, elastic and wrapped in a transparent capsule. The lens oppacity of AQP5-/- mice was increased more than that of wild-type (AQP5+/+ ) mice. In this study, we explored the potential functional role of circular RNAs (circRNAs) and transcription factor HSF4 in lens opacity in aquaporin 5 (AQP5) knockout (AQP5-/- ) mice. Autophagy was impaired in the lens tissues of AQP5-/- mice. Autophagic lysosomes in lens epithelial cells of AQP5-/- mice were increased compared with AQP5+/+ mice, based on analysis by transmission electron microscopy. The genetic information of the mice lens was obtained by high-throughput sequencing, and then the downstream genes were analysed. A circRNA-miRNA-mRNA network related to lysosomal pathway was constructed by the bioinformatics analysis of the differentially expressed circRNAs. Based on the prediction of the TargetScan website and the validation by dual luciferase reporter assay and RNA immunoprecipitation-qPCR, we found that circRNA (Chr16: 33421321-33468183+) inhibited the function of HSF4 by sponging microRNA (miR-149-5p), and it downregulated the normal expression of lysosome-related mRNAs. The accumulation of autophagic lysosome may be one of the reasons for the abnormal development of the lens in AQP5-/- mice.

Role of vascular endothelial growth factor and its receptors in the corneal tissue and corneal lesions / 中国组织工程研究

BACKGROUND: Vascular endothelial growth factors are a family of multifunctional cytokines that can enhance vascular permeability, induce angiogenesis, promote endothelial cel growth and migration, and inhibit cel apoptosis. OBJECTIVE:To elaborate the latest progress in the role of vascular endothelial growth factor and its receptors in the corneal tissue. METHODS:A computer-based search of PubMed databases was performed for relevant articles published from 2005 to 2015. The key words were “vascular endothelial growth factor, cornea”. According to the inclusion and exclusion criteria, 43 articles were included in result analysis. RESULTS AND CONCLUSION:Vascular endothelial growth factor and its receptors are involved in the regulation of corneal neovascularization by causing Tip cel activation that affects the Notch signaling pathways. Corneal lymphatic regeneration mainly relies on macrophages to secrete vascular endothelial growth factor-C or vascular endothelial growth factor-D that further activate vascular endothelial growth factor receptor-3 in the lymphatic endothelial cels to cause cel proliferation and migration, and eventualy lead to the formation of new lymphatic vessels. But herpes simplex keratitis HSK induces the corneal lymphatic regeneration by vascular endothelial growth factor-A/vascular endothelial growth factor receptor-2 pathway. Vascular endothelial growth factor family can significantly improve the damaged corneal nerve endings, epithelium and corneal sensitivity, has the function of nerve nutrition and promote restoration of the corneal epithelium.