Biomimetic cell-cell adhesion capillary electrophoresis for studying Gu-4 antagonistic interaction between cell membrane receptor and ligands

Abstract

We report a new method: biomimetic cell-cell adhesion capillary electrophoresis (BCCACE) to screen drugs targeting interactions between cell membrane receptors and ligands under an environment close to physiological conditions, in which the cell membrane receptors/ligands can maintain their natural conformations and bioactivity without being isolated and purified. Firstly, we screened twenty-one lactose derivatives by cell-immobilized capillary electrophoresis and obtained Gu-4 with the best activity (K = 3.58 ± 0.22 × 10⁴) targeting macrophage antigen-1 (Mac-1). Then, BCCACE was performed as follows: HEK 293 cells overexpressed with receptor (intercellular adhesion molecules-1, ICAM-1) were cultured and immobilized on the inner wall of capillaries as stationary phase, which simulated the endothelial cells lining on the inner surface of blood vessels. HEK 293 cells overexpressed with ligand Mac-1 as samples were used to simulate the neutrophils cells in blood vessels. And Gu-4 added into the running buffer solution as the antagonist was used to simulate the drug in blood. The results showed that Gu-4 (40 μM) could selectively inhibit cell-cell adhesion by targeting the interaction between Mac-1 and ICAM-1. Finally, the pharmaceutical efficacy assays of Gu-4 at cellular and animal levels were carried out using the concentration of 40 μM and the dose of 20 mg kg^-1 respectively, which showed the anti-cancer metastasis activity of Gu-4 and the validity of the method. This method simulated a complete three-dimensional vascular model, which can easily obtain the suitable blood concentration of drugs. This system simulated the interaction between leukocytes and vascular endothelial cells in the bloodstream antagonized by drugs, and obtained the effective concentration of the antagonist. It can be used as an accuracy and efficient drug screening method and will be expected to become a new method to screen drugs targeting cell-cell adhesion.

Keywords: Biomimetic cell-cell adhesion capillary electrophoresis; ICAM-1; Interaction between cell membrane receptor and ligands; Lactose derivatives; Mac-1; Screening drugs.