Immunophenotype of Replicative Senescent Mesenchymal Stromal Cells

Mesenchymal stromal cells (MSCs), a population of progenitor cells in adult tissues, are involved in the processes of physiological tissue renewal and damage-induced regeneration. MSCs have been widely studied as regenerative medicine agents. In this regard, the tissue-specific features of MSC subpopulations should be taken into account. MSCs have many potentially beneficial properties that can alter significantly with age. The ability of a cell to respond to external signals and regulate its functional state is commonly attributed to the repertoire of receptors on the cell membrane. This article considers the surface marker expression of senescent adipose-derived MSCs (AD-MSCs). Replicative senescence was caused by long-term cultivation. An increase in the expression of CD29, CD44, CD54, CD73, CD90, and HLA-ABC on the AD-MSCs was shown. The expression of CD105 and CD51/61 did not change reliably under the experimental conditions. The revealed effects are related not only to the larger cell size or higher autofluorescence, but also to the increased number of markers per unit area of the cell surface. The detected changes may underlie a number of modifications in the properties of senescent MSCs, including migration, adhesion, and immunomodulatory and angiogenic activities.