Inhibitory effect of miR­182­5p on retinal neovascularization by targeting angiogenin and BDNF.

Retinal neovascularization (RNV) is a type of serious vision­threating disease, commonly induced by hypoxia of ischemic retinopathy, which happens in various ocular diseases including diabetic retinopathy and retinopathy of prematurity. In clinical work, anti­VEGF therapy is the preferred strategy for treating RNV. However, not all cases are sensitive to anti­VEGF injection. It is urgent and necessary to develop novel targets for inhibiting neovascularization in ocular diseases. Angiogenin (ANG) and brain­derived neurotrophic factor (BDNF) are implicated in angiogenesis, although their regulation and effects in RNV remain to be elucidated. microRNA (miRNA) is a type of small non­coding RNA, which can modulate targets by degrading transcripts or inhibiting protein translation. In the present study, miRNA­mediated modulation of ANG and BDNF was explored in an oxygen­induced retinopathy mouse model and human retinal microvascular endothelial cells (HRECs) under hypoxia. The results showed that downregulation of miR­182­5p and upregulation of ANG and BDNF were found in vivo and in vitro. Overexpression of miR­182­5p suppressed the expression of ANG and BDNF significantly in HRECs under hypoxia. In addition, knockdown of ANG and BDNF by miR­182­5p transfection significantly improved hypoxia­induced HRECs dysfunctions, including enhancing cell viability, reducing cell migration and improved tube integrity. In conclusion, miRNA­dependent regulation on ANG and BDNF indicates a critical role in hypoxia­induced retinal microvascular response. miR­182­5p­based therapy can influence the expression of ANG and BDNF, which demonstrates the potential for treating RNV diseases.

Fish oil supplementation and repeated macular hemorrhage without choroidal neovascularization: A case report.

Macular hemorrhage can occur spontaneously and repeatedly without choroidal neovascularization or other known lesions associated with myopia. We report a case of repeated myopic macular hemorrhage following fish oil supplementation. A 32-year-old male was referred with newly acquired paracentral scotoma in the left eye. Serial retinal imaging, including fundus photography, fluorescein angiography, and spectral-domain optical coherence tomography were performed. Fundus photography and fluorescein angiography showed a subtle red-colored lesion nasal to the fovea. Optical coherence tomography showed a dome shaped elevation in the ellipsoid zone and interdigitation zone in the left eye. No known ocular risk factors for macular hemorrhage, such as choroidal neovascularization, lacquer cracks, Fuch's spot or choroid thinning or keratoconus were observed. After 2 months without any treatment, the left eye lesion disappeared. However 2 weeks later, another newly developed red-colored lesion close to the left fovea was observed. At that moment, the detailed medical history revealed that the patient had been regularly taking a high dose of commercially available fish oil supplement beginning one month before the first macular hemorrhage. After discontinuation of the fish oil, the second left hemorrhage resolved gradually over the following 8 weeks. No recurrent hemorrhages have been detected at the 12 months follow-up visits. Our observations suggest that the relative value of nutritional supplementation with high doses of fish oil should be cautioned in patients with repetitive retinal hemorrhage.