Age-related change in the reducible cross-link of human skin and aorta collagens

Can proteomics yield insight into aging aorta?

The aging aorta exhibits structural and physiological changes that are reflected in the proteome of its component cells types. The advance in proteomic technologies has made it possible to analyze the quantity of proteins associated with the natural history of aortic aging. These alterations reflect the molecular and cellular mechanisms of aging and could provide an opportunity to predict vascular health. This paper focuses on whether discoveries stemming from the application of proteomic approaches of the intact aging aorta or vascular smooth muscle cells can provide useful insights. Although there have been limited studies to date, a number of interesting proteins have been identified that are closely associated with aging in the rat aorta. Such proteins, including milk fat globule-EGF factor 8, matrix metalloproteinase type-2, and vitronectin, could be used as indicators of vascular health, or even explored as therapeutic targets for aging-related vascular diseases.

Human biological decline and mortality rates

Intercepts on the x (age)-axis of 107 normalized declining human biological functions were determined and assembled in 3 histograms, being placed in increasing order within each decade (10 year period). The histograms were classed accordingly as they contained properties associated with dividing cells, sensory properties and non-dividing cells respectively. Their cumulants were determined, multiple regressions calculated and compared with current death-rates for women and men respectively, for 10 amongst the longest living populations in the World. An alternative verification based on risk theory led to an estimate of an optimal life expectancy of 96 years. The survival curve turns out to be of the form (See text: Formula) where the inner integral represents the cumulant dimension (t') and the outer one age (t"). The premises underlying this study are compatible with the notion of a probable life-span, rather than a fixed one.

Why does the human visual system age in the way it does?

The tentative observation that the decrease of lenticular glutathione in man and in cattle may be under genetic control is extended to other biological functions which show a systematic reduction with age. Ocular and visual parameters are shown to decline consistently with the view that the human eye has evolved in keeping with other biological functions sustaining a life-span of approximately 120 years. Analysis of the data suggests that presbyopia represents an outlier in the distribution of ocular attributes, and should not be used as a biomarker for ageing.

Human sensory functions and longevity

Age-related variations of human sensory properties have been expressed in a manner which permits them to be validly compared with other biological functions presented on a similar basis. They are found to be representative of much larger data-base, and it is tentatively suggested that they may have evolved in support of a life-span of approximately 120 years. Some theoretical arguments are advanced to explain this.

Have human biological functions evolved in support of a life-span?

Published data on age-related human biological functions are surveyed. For the many showing a linear decrease, regressions were calculated, or existing functions extrapolated, to yield an intercept on the abscissa. The values of chi(0), the age at which a function ceases, provide a tentative common means of comparison. The distribution of chi(0) is skewed because of the apparent longevity of nervous and cerebral functions. The database is sufficiently large to enable one to distinguish those biological functions which appear to have immediate survival value from those which do not. Such an approach may link biomarkers to estimates of the life-span of species.