Voltage-Gated Sodium Channels Regulate the Migration Potential of Human Endometrial Mesenchymal Stem/Stromal Cells in 2D and 3D Culture.

Human endometrial mesenchymal stem/stromal cells (eMSCs) are widely used in laboratories and clinical applications to study various aspects of tissue engineering and regenerative medicine. Three-dimensional (3D) cultivated MSCs have a higher therapeutic efficacy compared to 2D culture. Ion channels are involved in maintaining many physiological cell functions, including proliferation, differentiation, apoptosis, and migration. This study describes the functional expression of voltage-gated sodium channels (NaV) in eMSCs and the role of these channels in cell migration. Using RT-PCR analysis and immunofluorescent microscopy, we identified the expression of almost all pore-forming alpha (NaV 1.1, 1.2, 1.4-1.9) and channel-modulating beta-NaV subunits (except beta2) in eMSCs. In the whole-cell patch-clamp configuration, channels activated by membrane depolarization of eMSC were detected. The channels were blocked by the selective NaV antagonist TTX in nanomolar concentrations. The NaV agonist veratridine at a concentration of less than 40 μM inhibited voltage-gated sodium currents, while 100 μM and above prevented channel inactivation. The wound healing assay showed that both TTX (10 μM) and veratridine (100 μM) reduced the migration properties (the wound healing rate) of eMSCs cultivated in 2D conditions compared to the control. An opposite effect by both agents was shown on the motility of eMSCs cultivated in 3D conditions, increasing the cell spreading rate from spheroids. Our data suggest that NaV channels are expressed in human eMSCs and play an important role in the regulation of stem cell migration; this regulatory mechanism significantly depends on the culture conditions of MSCs.