Telomere senescence mechanism

Telomeres (English name: Telomeres) are gene repeats at the ends of linear chromosomes. A special structure at the end of the mitochondria, a small piece of DNA-protein complex at the end of a linear chromosome of a eukaryotic cell that, together with the telomere-binding protein, forms a special "hat" structure that maintains chromosome integrity. And control the cell division cycle. Telomeres, centromeres, and origin of replication are the three major factors that keep chromosomes intact and stable. Telomere DNA is composed of simple DNA highly repetitive sequences. Telomerase can be used to tail the telomeric DNA. Each time the DNA molecule is split, the telomere is shortened (such as the Okazaki fragment). Once the telomere is consumed, the telomere is consumed. The cell will immediately activate the apoptotic mechanism, ie the cell goes to apoptosis. Therefore, the length of telomeres reflects the history of cell replication and the potential for replication, and is called the "mitotic clock" of cell life. Studies have shown that the telomere length decreases with age and decreases by 51.3 bp every year at 30-49 years old, and 19.8 bp every year at 40-80 years old. Each time the cell divides, the chromosome will lose a part of the telomere DNA sequence. When it is shortened to a critical length, the length of the terminal restriction fragment (Hayflick limit), the length of the telomere is also referred to as the "life clock" because telomeres may also limit the number of cell divisions.

The position of the telomere in the mitochondria

Telomere senescence

Free radical aging mechanism

Mitochondrion is the structure of energy production in cells, the main place for cells to perform aerobic respiration, and the workshop of energy. When there is an excess of oxygen in the mitochondria, an oxidative stress reaction occurs immediately. The free radicals generated in the tissues of the body accumulate and accumulate in large amounts. Free radicals can cause DNA damage and cause mutations, which induce tumor formation. Free radicals are intermediates of normal metabolism, and their ability to react is strong, which can oxidize various substances in cells and damage biofilms. It can also crosslink macromolecules such as proteins and nucleic acids, affecting their normal functions.

Cell structure

The mechanism of free radical aging can clearly explain the various symptoms that appear in the body's aging process, such as spots, wrinkles and decreased immunity.

The study found that Haematococcus pluvialis natural astaxanthin has superior antioxidant capacity, can capture lipid free radicals, superoxide free radicals and lipid-like free radicals in the body, exerting anti-oxidation effect and preventing lipofuscin formation; Protects the unsaturated fatty acids in the membrane phospholipids, stabilizes the biofilm structure, and maintains the normal function of the membrane.