Rapid increase in human life expectancy: will it soon be limited by the aging of elastin?
The postponement of the most frequent age-related diseases stimulated speculations of the possibility of "dying of old age". The selective decline of individual physiological functions-aging in spare-parts-indicates however the potential limitation of the life-span by the rapid decline of some of the vital parameters. We explored a possibility of such a limitation of maximal life-span by the age-related alteration of elastin, consisting in Ca-accumulation, lipid deposition and elastolytic degradation. The quantitative evaluation of these processes suggests an approximative upper limit for the elastic properties of the cardio-respiratory system of about 100-120 years, at least, as far as elastin is involved. This process, age-related alterations of elastic fibers, is however not the only one limiting the functional value of the cardiovascular system. Crosslinking of collagen fibers by advanced glycation end-products certainly contributes also to the age-dependent rigidification of the cardiovascular system. Therefore the answer to the initial question, can age-dependent alterations of a single matrix macromolecule be limiting such vital functions as the cardio-respiratory system-is a cautious yes, with however the caveat that other, independent mechanisms, such as the Maillard reaction, can also interfere with and limit further the functional value of such vital physiological functions.
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Laboratoire de recherche ophtalmologique, Hôpital Hôtel Dieu, 1 place du parvis Notre Dame, 75181, Paris cedex 04, France.
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D000375:Aging / Q000378:metabolism*; D001808:Blood Vessels / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002319:Cardiovascular System / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D004548:Elasticity; D004549:Elastin / Q000378:metabolism*; D006801:Humans; D008017:Life Expectancy; D050356:Lipid Metabolism; D015416:Maillard Reaction; D010447:Peptide Hydrolases / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D012137:Respiratory System / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D013997:Time Factors
D011956:Receptors, Cell Surface; C054901:elastin-binding proteins; D004549:Elastin; D010447:Peptide Hydrolases; D002118:Calcium