When cells do not enter apoptosis, the body’s natural programmed death of cells, they become senescent. The accumulation of these types of cells can emit potentially harmful chemical signals to nearby cells that encourage the same senescent state.
Senescent cells can cause the degradation of tissue function and can increase levels of chronic inflammation, a common factor in age-related diseases. Senescent cells increase inflammation by secreting pro-inflammatory cytokines, chemokines and extracellular matrix proteases. This process is known as the Senescence Associated Secretory Phenotype (SASP), or a set of physical characteristics that contribute to aging and cancer.