Abstract
Background: Gamma-aminobutyric acid type A (GABAA) receptors are thought to play a role in the functioning of the immune system. GABAA receptors have 19 types of subunits, the components of which determine their physiological functions. However, the subunits that are expressed in immune cells during inflammation have not been fully investigated. Recent reports have shown that anesthetic agents may affect the gene expression of GABAA receptors subunits in immune cells. Therefore, we aimed to investigate the changes in GABAA receptor subunit gene expression during macrophage differentiation and propofol administration in order to clarify the relationship between the expression of GABAA receptors and the immunomodulatory effect of propofol.Methods: Human acute monocytic leukemia (THP-1) cells were differentiated into macrophage-like cells (M0 THP-1); subsequently, M0 THP-1 cells were differentiated into inflammatory M1 macrophage-like cells (M1 THP-1). Propofol was administered during the differentiation into M1 THP-1 cells. Using reverse transcriptase polymerase chain reaction, we examined which GABAA receptor subunit genes were expressed and whether there were changes in the gene expression during macrophage differentiation and propofol administration in THP-1 cells.Results: The expression of the α1, α4, β1, β2, γ1, and γ2 subunits increased during differentiation into M0 THP-1 cells. The expression of the α1, α4, β1, β2, γ2, and δ subunits decreased and that of the γ1 subunit increased during differentiation into M1 THP-1 cells. The gene expression of the α1, α4, and β2 subunits increased upon administering propofol during differentiation into M1 THP-1 cells.Conclusions: The gene expression of GABAA receptor subunits changed during macrophage differentiation in THP-1 cells. The expressions of α1 and α4 increased following propofol administration during the differentiation into M1 THP-1 cells, which may indicate that the GABAA receptor is involved in the immunosuppressive effects of propofol. This study can help in the choice of anesthetic agents for proinflammatory conditions such as highly-invasive surgery.
Amino acids lining the channel of the gamma-aminobutyric acid type A receptor identified by cysteine substitution.
