Changes of lysosomes in the earliest stages of the development of atherosclerosis.
Bottom Line: One of hypotheses of atherosclerosis is based on a presumption that the zones prone to the development of atherosclerosis contain lysosomes which are characterized by enzyme deficiency and thus, are unable to dispose of lipoproteins.There were no significant changes found in the key mRNAs encoding for the components of endosome/lysosome compartment in initial atherosclerotic lesions, but in fatty streaks, the contents of EEA1 and Rab5a mRNAs were found to be diminished while the contents of CD68 and p62 mRNAs were increased, compared with the intact tissue.The study reinforces a view that changes occurring in lysosomes play a role in atherogenesis from the very earlier stages of the disease.
Affiliation: Faculty of Medicine, School of Medical Sciences, University of New South Wales, Kensington, NSW, Australia. email@example.comShow MeSH
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Mentions: Ultrastructural examination of numerous profiles of cells residing in the normal intima revealed characteristic round and oval shapes of lysosomes (Fig. 1A). In these cells, lysosomes were filled with a homogenous material of middle or high electron density (Fig. 1A). In the initial lesions (Type I lesion), the presence of inclusions within some lysosomes were detected (Fig. 1B and C). Electron density of the lysosomal ‘matrix’ was quite irregular in these lysosomes (Fig. 1B and C). The cells, containing some lipid inclusions in the initial lesions contained a well-developed vacuolar-lysosomal apparatus while they did not contain visible filaments or the basal membrane and thus were identified as macrophages. In cells in fatty streaks (Type II lesion), some lysosomes were presented by secondary lysosomes and autophagosomes which contained lipid inclusions (Fig. 2A–C). Some of the lipid-laden cells in fatty streaks contained a large number of lipid inclusions and autophagosomes.
Affiliation: Faculty of Medicine, School of Medical Sciences, University of New South Wales, Kensington, NSW, Australia. firstname.lastname@example.org