Modifications of the Secretome of Mesenchymal Stromal Cells under Conditions of Stress-Induced Aging

It is known that the senescence-associated secretory phenotype (SASP) can promote senescence of surrounding normal cells. However, SASP signaling during senescence of mesenchymal stromal cells (MSCs) has not yet been fully studied. We determined the pattern of secreted proteins specific to MSCs under stress-induced senescence. Using chromatography-mass spectrometry, proteins specific to the secretome of senescent or "young" cells were identified. The secretome of senescent cells contains proteins both associated with senescence (LOXL2, CCL2, PLAT, SERPINE2, etc.) and important for reducing the impact of these processes, in particular, proteins responsible for inhibition of oxidative stress (MIF, PRDX5, GSTM2), detoxification of methylglyoxal (GLO1), and suppression of inflammatory reactions (GAS6, GSTM2). The obtained results indicate the complex etiology of aging and the ambiguity of the function of SASP within the paracrine induction of aging of neighboring cells.