Mikhail A Ostrovsky
Institute of Biochemical Physics—Russian Academy of Sciences, Russia
Title: Study of lipofuscin granules and melanosomes from human retinal pigment epithelium Mikhail A Ostrovsky
Biography
Biography: Mikhail A Ostrovsky
Abstract
Lipofuscin granules (LGs) accumulate in the retinal pigment epithelium (RPE) cells with age, particularly in patients with hereditary diseases. Photosensitization of LGs with blue light can generate reactive oxygen species. Defined differences in fluorescence properties between chloroform extracts obtained from cadaver eyes with and without signs of pathology hold promise for the future improvement of fundus autofluorescence imaging. There is a significant age-related decrease for melanosomes in the RPE cell due to its biodegradation. Oxidants, such as hydrogen peroxide or superoxide radicals, easily lead to melanin destruction. For example, superoxide radicals lead simultaneously both to decrease the amount of melanosomes and concentration of paramagnetic centers of the melanin. We suggest that the age-related loss of melanosomes in the RPE cell is due to melanin destruction in the complex melanolipofuscin granules; superoxide radicals light-induced by LGs cause the destruction. The accumulation of LGs as source of free radicals along with autofluorescence and loss of melanosomes as screening and antioxidant pigment in the RPE cells with age can lead to photo-oxidative stress which is related to the progression of serious eye pathologies. The lecture reviews the recent advances in knowledge of the RPE lipofuscin granules and melanosomes.