Aging: How Science Works

Aging is a topic that concerns all of us, since none of us can escape it. The molecular and cellular process is built in every of the billions of cells forming our body. Some of these cells, such as immune cells and red blood cells, live only for a few days to weeks and get life-long constantly replaced by cells produced in the bone marrow. In contrast, there are cells, such as neurons and memory lymphocytes, that get as old as we get. The process of aging limits our maximal life span, which is for our humans 120 years. However, only a very few individuals reached this age. How did their life differ from others that died decades earlier? Is it just the absence of life threatening disease paired with a more healthy life style? Or is it build in in our genome or epigenome? In this book we try to give answers to these questions from the perspectives of evolution, our genome, the epigenomes of our different tissues and cell types and the functionality of our cells. We should try to understand ourselves in detail as well as in a global setting. Basic biology explains cellular mechanisms, such as growth, differentiation, and cell death, which make life as a whole possible. Every (human) organism represents a complex interplay between hundreds of different cell types forming distinctive tissues and organs with specialized tasks. These processes need to be highly orchestrated especially during development, maintenance and aging. Studying the cellular and molecular basis of aging is one of the most fascinating areas but also a great challenge. Nevertheless, research made the biggest steps in elucidating biological processes via studying malfunctions of normal mechanisms leading to different diseases, such as progeroid syndrome and cancer. We will start this book with the understanding of the human genome in relation to principles of evolution. Then we will explain the basics of gene regulation and epigenetics, i.e., the interplay of transcription factors and chromatin.…