Time-of-flight secondary ion mass spectrometry to assess spatial distribution of А2Е and its oxidized forms within lipofuscin granules isolated from human retinal pigment epitheliumстатья
Статья опубликована в высокорейтинговом журнале
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Дата последнего поиска статьи во внешних источниках: 4 декабря 2016 г.
Аннотация:Lipofuscin granules accumulate in the cells of retinal pigment epithelium with age, particularly in patients with hereditary diseases. These granules are heterogeneous, being composed of mixtures of proteins and lipids, including more than 21 different fluorescent compounds. Bisretinoids and their photo-oxidation and photodegradation products represent the main source of lipofuscin fluorescence and exhibit phototoxic properties. This study used time-of-flight secondary ion mass spectrometry (ToF-SIMS) with in-depth probing to assess the depth distribution of N-retinylidene-N-retinylethanolamine (А2Е) and its singly and doubly oxidized forms (А2Е-ox and А2Е-2ox, respectively) within lipofuscin granules and in their surface layer (lipid membrane). ToF-SIMS showed that А2Е and its oxidized forms were uniformly distributed throughout lipofuscin granules but were not present at the membrane surface layer. This finding is important for understanding the process involved in the formation of lipofuscin granules and in their toxicity.