Cilioretinal artery: Vasculogenesis might be promoted by plasminogen activator inhibitor-1 5G allele

Plasminogen activator inhibitor-1 4G/5G polymorphism and dyslipidemia with branch retinal artery occlusion in a young lady

Branch retinal artery occlusion (BRAO) leads obstruction of blood flow in the distribution of the affected vessel giving rise to ischemia and reorganization of the retinal layers. It is a very rare diagnosis and the etiological risk factors of BRAO are not clean in the young population. Various hypercoagulable states leading to thrombosis appeared to be more responsible. Here, the authors present an interesting case of a 25-year-old female patient with BRAO accompanying with plasminogen activator inhibitor-1(PAI-1) 4G/5G gene polymorphism and dyslipidemia together, for the first time. There was a history of sudden painless blurred vision in her right eye 3 months ago. Her visual acuity was 20/20 in both eyes at the admittion. Fundus photo, red-free photo, optical coherence tomography images of 3 months ago revealed BRAO in the right eye. Fundus exam and images taken at the 3th month confirmed the recovery of retinal edema. Attenuation of inferotemporal retinal artery still mildly appeared. Applied confrontation fields showed a visual field defect corresponding with affected area. Ophthalmologists are advised to be aware of the importance of PAI-1 4G / 5G gene polymorphism and dyslipidemia conditions besides the other genetic mutations and thrombophilic markers regarding BRAO in young patients.

Integrin α5β1 promotes BMCs mobilization and differentiation to exacerbate choroidal neovascularization

Choroidal neovascularization (CNV) is an acknowledged pathogenic mechanism of various ocular diseases, and in situ cells and mobilized bone marrow-derived cells (BMCs) are thought to participate in this process. We aimed to evaluate the roles of integrin α5 in BMCs and vascular endothelial cells (VECs) in the CNV process mediated by SDF-1/CXCR4 signaling. Adult wild-type mice were engrafted with whole BMCs obtained from GFP transgenic mice and then laser injured to induce CNV. BMCs and RF/6A cells were cultured to discover the mechanism of CNV in vitro. BMCs were mobilized to CNV areas, which expressed elevated SDF-1 and CXCR4. When SDF-1 was intravitreally injected, the number of BMCs was profoundly increased. In the SDF-1-treated group, the levels of integrin α5 expressed on BMCs and VECs were significantly higher than those on the cells in the control group. SDF-1 significantly increased the expression and positive ratio of integrin α5, which was involved in the recruitment and differentiation of BMCs into BMC-derived VECs, and these effects were suppressed by the CXCR4 inhibitor AMD3100. The PI3K/AKT pathway rather than the ERK pathway mediated SDF-1/CXCR4 induction of integrin α5. Integrin α5 suppression efficiently prevented the production of TGF-β and bFGF but not VEGF. Inhibiting the SDF-1/CXCR4-PI3K/AKT-integrin α5 axis reduced CNV severity. Integrin α5 participates in BMC recruitment and differentiation in SDF-1/CXCR4-induced CNV and inhibition of this pathway may be a new approach to inhibit CNV.