PhD Scientific Days 2024

Poster Session D - Neurosciences 1.

Pro-activating Effects of Exposure to Different AlCl3 Concentrations on Microglial Cells in Vitro

Text of the abstract

Introduction. Microglia are resident macrophages of the CNS. Under physiological conditions, their main functional state is «resting» one, but microglia can be polarized towards pro-inflammatory M1 or anti-inflammatory M2 activated state in response to increased production of reactive oxygen species (ROS), which can be promoted due to inflammaging and age-related diseases. Ions of aluminum are known as strong ROS production promoters, and although their short-term impact on microglia are described, long-term effects and consequences remain scarcely understood.
The aim was to examine morphofunctional and molecular biological changes in microglial cells cultured with AlCl3.
Materials and methods. Mature mouse microglial cells (BV2 cell line) were cultured under standard conditions in presence of 0.5 and 1 mM of aluminum chloride (AlCl3) for 140 hours, which correspond to two growth cycles. Examination of microglia features changing were performed via evaluation of ROS production, apoptosis processes, and activation markers expression using flow cytometry, PCR-RT, and ELISA.
Results. Both AlCl3-treated groups demonstrated less ROS production, upregulation of M1 marker Tnf-a mRNA expression, and its downregulation of M2 marker Arg1. Relative to control, cells of 0.5 mM AlCl3-treated group displayed the lower percent of late apoptotic cells, as well as M2 polarized CD206+ ones. Such distinctions might occur due to successful adaptation and the return to the «resting» state. In 1 mM AlCl3-treated cells supernatant, there was lower level of HIF-1a protein, which is responsible for adaptation to hypoxia and supposed to be increased in M1 activated macrophages, but higher levels of IL-1β and HSP70 relative to control. It presumably indicates an altered activation and an increase of proteins misfolding, which is a long-term consequence of prolonged low-grade adverse impact.
Conclusion. Chronic exposure to 0.5 mM AlCl3 led to microglia adaptation and «healthy aging», whereas impact of 1 mM AlCl3 resulted in persistent activation alongside with probable initiated dysfunction. Lower dose of AlCl3 created conditions of eu-stress, while higher dose resulted in inflammaging and excessive stress features. These data might be used as a reliable in vitro model of inflammaging suitable for further investigation in this field.
Funding - the state assignment № 122030200530-6.