The Effects of Hyaluronan (HA) derivates on the Redox State and HA Receptor Expression in Monocytes/Macrophages

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

Congreso; Congreso de la Sociedad Argentina de Investigaciones Bioquímicas (SAIB) 2023; 2023

Hyaluronan (HA) is a glycosaminoglycan that is found in the extracellular matrix. It is involved in many bodily processes, including clearing away harmful reactive oxygen and nitrogen molecules. This process involves breaking down HA into small fragments that can trigger inflammation through the CD44-TLR4 receptor cluster. However, the effects of HA and its derivatives on inflammation when administered externally have not been well-studied. This study aimed to assess how different types of HA affect the redox state and HA receptor expression in the immune cells monocytes/macrophages (Mo/MØ). Mo were purified from peripheral blood of healthy donors (n=3) by Ficoll gradient centrifugation and subsequent positive selection using magnetic beads. Mo were cultured under standard culture conditions in multiwell plates overnight. Subsequently, they were treated for 24 hours with low molecular weight HA (LMW HA), partially sulfated HA (sHA 1), and fully sulfated HA (sHA 3), at a concentration of 100 µg/mL, and IFN-γ and IL-4 at a concentration of 10 ng/mL, as differentiation controls. At the end of the treatments, we determined (a) the viability of Mo/MØ by MTS assay at different times (4, 8, 24, 48, 72 h), (b) the concentration of nitrites, in culture media and protein lysate, by Griess assay, and the activity of the antioxidant enzyme catalase by Aebi assay and (c) the expression levels of HA receptors (CD44, RHAMM, HARE, TLR2, TLR4). HA derivates species increased the viability of Mo/MØ and modified the redox state and HA receptor expression compared to the control without treatment. These results highlight the importance of HA and derivatives as modulators of oxidative stress mediated by Mo/MØ. However, further studies are required to understand the mechanisms that trigger this process and its implications in disease contexts and therapeutic use.