Effects of exosomes in pathogenesis of age-related macular degeneration

Exosomes are nanometer membranous vesicles which can be distributed in a variety of biological fluids, including peripheral blood, urine, saliva and so on.Currently, the multi-step differential centrifugation is a efficient method which can be used to isolate exosomes.Exosomes are released by all types of cells.Exosomes can carry proteins and RNAs from derived cells, involve in exchange of information between cells, and play an important role in physiological and pathological processes of immunoregulation and inflammatory responses.Age-related macular degeneration (AMD) is the leading indication of severe visual impairment in adults over 50 years old.The exact etiology of AMD is still unknown, and its pathogenesis may involve various factors.New studies showed that exosomes secreted by retinal pigment epithelium (RPE) cells may be associated with AMD.The elevated levels of protein in exosomes from RPE, such as αB-crystalline, are associated with druse in AMD.Stress-altered exosomes proteins were found involving in regulation of apoptosis and survival of RPE.RPE cells membrane complement regulators, CD46 and CD59, could contribute to lesion formation in the outer retina and Bruch’s membrane during the development of AMD.Further, exosomes from RPE cells may be associated with the genesis of choroidal angiogenesis.There remain thorough studies to be conducted, which would reveal new approaches for the diagnosis and treatment of AMD in the future.