Hyaluronan and chemical derivatives affect monocyte/macrophage interaction with mesenchymal stem cells under co-culture conditions

ICARDI, ANTONELLA; ROSALES, PAOLO; VITALE, DAIANA L.; DELSOUC, MARÍA BELÉN; CASAIS, MARILINA; SEVIC, INA; ALANIZ, LAURA D.

Congreso; Congreso SAIB 2022; 2022

Monocytes/macrophages (Mo/MØ) are key regulators of tissue repair and regeneration, and their proper activation is necessary for tissue homeostasis. Along with Mo/MØ, mesenchymal stem cells (MSCs) have gained importance in regenerative contexts. Hyaluronan (HA), one of the main components of the extracellular matrix, interacts with MSCs, being able to regulate their functional profile. Numerous antecedents demonstrate a proactive interaction between MSCs and Mo/MØ, however, the role of this interaction in a regenerative context is unknown. Since the activation of Mo/MØ is an event that leads to changes in the redox balance and the development of the inflammatory process, we evaluated the production of oxidative stress and inflammatory factors by these cells under stimulation of the MSCs secretome and in direct co-culture. To do this, MSCs were treated with HA (MSCs HA) and with its sulfated chemical derivatives (MSCs sHA1 and MSCs sHA3) at a concentration of 100 µg/ml for 48 h. Next, Mo/MØ from peripheral blood, enriched by Ficoll/Percoll gradient, were cultured with treated and untreated MSCs (MSCs BC) in a 1:10 ratio (MSCs:Mo/MØ) for 72 h or stimulated with the secretome derived from these cells. The total antioxidant capacity (TAC) was determined by the ABTS•+ cation inhibition assay, the induction of the antioxidant enzyme catalase (CAT) by the Aebi method, and the levels of nitrite, a water-soluble and stable nitric oxide metabolite, were measured spectrophotometrically by Griess reaction. Furthermore, we analyzed the expression level of TSG-6 mRNA under these conditions by RTqPCR. The data obtained was analyzed using the GraphPad Prism software. We show that the antioxidant status of Mo/MØ did not change after secretome stimulation of MSCs treated with HA and sulfated derivatives compared to the basal condition. However, the antioxidant status of Mo/MØ was regulated in the co-culture system. We found a higher TAC (p