What is STAT5B?

STAT5B belongs to the STAT (signal transducer and activator of transcription) protein family, a group of latent cytosolic transcription factors activated by Janus kinase (JAK) tyrosine kinases. The JAK-STAT signaling pathway is responsible for many important biological processes including cell proliferation, differentiation, apoptosis, and is also involved in the modulation of a variety of cytokines to control the immune response. 

Oxidative stress is an imbalance between the production of reactive oxygen species (free radicals) and antioxidant defenses. [1] The body’s cells produce free radicals, which are nitrogen- or oxygen-containing molecules with an uneven number of electrons [2], during normal metabolic processes. [3] Meanwhile, cells also produce antioxidants that neutralize these free radicals to prevent excessive cell and tissue damage. In general, the body is able to maintain a balance between antioxidants and free radicals. [3] However, this balance could be disrupted under certain conditions or environmental stress or infection, and uncontrolled oxidative stress can accelerate the aging process.[3]

Reaching the golden years doesn’t always feel so golden. As we age, disease, injury, and other stress factors from the environment will damage our bodies' cells. Most cells may be able to repair that damage, while our immune system usually clears those damaged cells through a process called apoptosis.^[1] However, if cellular repair and clearance is not effective, the residual damaged cells will further weaken the immune system and deteriorate other biological processes. Is there a possibility that we can avoid this cellular damage and improve the health of older people? A cellular state known as senescence might hold the key to this question.^{[1, 2]} During senescence, the damaged cells irreversibly stop dividing and resist being removed. ^[3] Researchers have shown that determining senescence biomarkers could lead to new therapies for the inflammatory disease caused by senescence in older people.^[4]