On the Origin of Heterogeneity of Lipofuscin Fluorophores and Their Possible Interrelations

Abstract

A comparision of the response of different cell types (thymus, spleen, liver, tumor) to the development of oxidative stress was investigated on an experimental model of tumor growth in vivo. Only spleen cells exhibited the yellow-red fluorescent pigment with high resistance to oxidative stress (as is typical for age-related lipofuscin pigment). Under oxidative stress, the cytoplasm in normal cells showed a tendency foward increased levels of fluorescent products of protein or lipid peroxidation, which was opposite from the response of tumor cells. In the present paper a novel hypothesis of lipofuscinogenesis is developed where oxidative stress is considered to be a trigger for switching on some adaptive cell pathways whose activity is associated with the induction of specific groups of cellular fluorophores.

Distribution of Inorganic Mercury in Liver and Kidney of Beluga and Bowhead Whales Through Autometallographic Development of Light Microscopic Tissue Sections

“…Lipofuscin consists of polymerized, oxidized lipids with some protein constituent (6,30,34) and its formation re ects oxidative stress and associated intracellular damage, although not necessarily of suf cient magnitude to impair form or function. Rather, it accumulates in a variety of tissues and cell types as a normal consequence of agingrelated processes, and may represent products of various cellular defense mechanisms that protect against free radicals (33,47). The golden-brown intracellular pigment observed in beluga and bowhead whale tissue sections uoresced at a wavelength consistent with that of lipofuscin, corroborating light microscopic observations and identi cation (44).…”

An Overview of the Role of Lipofuscin in Age-Related Neurodegeneration

“…LF fluorescence shows a large heterogeneity in the emission spectra, which reveals differences in its chemical composition, as a result of its ripening in specific metabolic pathways (Schwartsburd, 1995 ). In general, the LF fluorescence emission presents a very wide spectra ranging from 400 to 700 nm, with a maximum around of 578 nm for excitation at 364 nm (Warburton et al, 2007 ).…”

“…Opposite, cancer cells, unable to accumulate LF particles are more susceptible to the action of the drug. In this sense, Schwartsburd in 1995 put forward the idea that lipofuscinogenesis is an adaptative cell response to oxidative stress that improves cell survival under harsh conditions (Schwartsburd, 1995 ). In Drosophila melanogaster , a similar protective effect of LF is suggested by spin gene mutants that presented degeneration of adult neural cells, while surviving neurons were atrophied with heavy LF deposition (Nakano et al, 2001 ).…”

Self-cytoprotection against stress: feedback regulation of heme-dependent metabolism

“…Examples are found in the cardiovascular action of aspirin, which, in low concentration, can induce apoferritin synthesis in endothelial cells (Oberle et al 1998) and by this pathway can contribute to vessel protection against stress-induced injury. An endogenous decline in this defense occurs frequently under stressful conditions, like rapid aging and the paraneoplastic disorders, the progression of which coincided with ferritin inactivation by oxygen-derived free radicals in vivo (Schwartsburd 1995(Schwartsburd , 1998.…”