Cell senescence

Cell senescence is observed when cells stop dividing. This happens when telomeres, which protect the end of the chromosome, become progressively shorter reaching the Hayflick limit (limit to cell division capacity), meaning that human cells can only divide a finite number of times. In Cell senescence includes progressive and irreversible loss of cellular functions leading to the death of some cells.

Whenever a cell division occurs, the telomere loose length and become shorter. When they reach a minimum size, chromosome duplication ceases to occur, disabling cell division.

During this process, beta-galactosidase (enzyme responsible for hydrolysis of lactose in galactose and glucose) is detected in cell’s lysosomes, indicating senescent cells.

This process is not yet fully known, raising some doubts, which leads to the emergence of several theories. Studies show that cellular senescence may be a manifestation of loss of telomerase activity. This ribonucleoprotein is an enzyme that adds DNA sequence repeats in telomere region and thereby restores the ability of cell multiplication and retards the aging of tissues. During development, the telomerase function decline and telomeres become shorter.