Fig. 1
From: Epigenetic modifications in thymic epithelial cells: an evolutionary perspective for thymus atrophy
The features and epigenetic changes of TEC senescence. Cellular senescence is characterized by abnormal cell enlargement, cell cycle arrest (by upregulation of p21 & p16 cell cycle inhibitors), resistance to apoptosis (by upregulation of the BCL-2 family), SASP (by upregulation of cytokines, chemokines, extracellular vesicles), and SAHF, metabolic dysfunction (the positive of SA-β-gal staining). Epigenetic changes include DNA methylation, histone modifications and chromatin remodelling, which together play a fine-tuning role in the development, differentiation, and senescence of TECs. SASP, senescence-associated secretory phenotype; SAHF, senescence-associated heterochromatin foci; SA-β-gal, senescence-associated-β-galactosidase; DD, DNA damage; EV, extracellular vesicles