Theories of aging: an ever-evolving field

Abstract

Senescence has been the focus of research for many centuries. Despite significant progress in extending average human life expectancy, the process of aging remains largely elusive and, unfortunately, inevitable. In this review, we attempted to summarize the current theories of aging and the approaches to understanding it.

Keywords: accumulation of damage; advanced glycation end-product; aging; life expectancy; reactive oxygen species; telomerase.

Fig. 1

The mitochondrial respiratory chain, illustrating electron transfer from NADH and FADH₂ to oxygen

Fig. 2

A schematic representation of ATP synthase structure and function

Fig. 3

Lysosomal transport. A schematic representation of vesicular transport in the cell. Red arrows indicate the flow of material form the cellular membrane (material absorbed by the cell), the cytoplasm (for example, defective mitochondria to be degraded), and from the endoplasmic reticulum (lysosomal enzymes) to lysosomes

Fig. 4

Structure of the low-density lipoprotein (LDL), the major carrier of plasma lipids (A), and formation of the atherosclerotic plaque (B)

Fig. 5

Formation of β -amyloid and polymerization

Fig. 6

Spontaneous glycation of proteins

Fig. 7

Simplistic representation of the insulin/IGF-1 signal pathway