Effect of Multipotent Mesenchymal Stromal Cells on Functional Activity of Monocyte-Derived Macrophages under Short-Term Hypoxic Stress in Vitro

Abstract: The study focused on the interaction between mesenchymal stromal cells (MSCs) and monocyte-derived macrophages (MN/MPs). The interactions play an important role in MSC in vivo indirect therapeutic effects and anti-inflammatory and immunomodulatory properties. To assess the MSC effect on MN/MP functional activity, MSCs and MN/MPs were co-cultured in standard conditions (20% O2) for 6 days. Then part of MN/MP and MN/MP + MSC cultures was exposed to short-term hypoxic stress (1% O2, 24 h), while the other part was further cultured at 20% O2. In both standard conditions and hypoxia, MSCs exerted stromal activity and increased the MN/MP viability by decreasing the MN/MP portion undergoing early apoptosis. A paracrine interaction stimulated phagocytic activity of MN/MPs without affecting activity of the lysosomal compartment at 20% O2. Hypoxic stress decreased the MSC-induced phagocytic potential and lysosomal activity. An anti-inflammatory phenotype developed in MN/MPs upon their interaction with MSCs, and MN/MPs consequently better utilized their phagocytic potential in the presence of MSCs in spite of oxygen deprivation. © 2022, Pleiades Publishing, Inc.