IL-10 and TGF-beta Increase Connexin-43 Expression and Membrane Potential of HL-1 Cardiomyocytes Coupled With RAW 264.7 Macrophages

Cardiomyocytes and macrophages have been found to interact via connexin-43 hemichannels. The role of connexin-43, however, is not fully understood. This study shows that these interactions aid in increasing the membrane potential of cardiomyocytes allowing contraction of the cells. HL-1 cardiomyocytes and RAW 264.7 macrophages in coculture increased expression of connexin-43 compared to cardiomyocytes alone. Co-cultures also increased the fluorescence of Di-8-ANEPPS potentiometric dye indicating an increase in cardiomyocyte membrane potential. Treatment with IL-10 and TGF-beta further increased connexin-43 expression and membrane potential. Treatment with SOCS3 inhibited the effects of TGF-beta and IL-10 while having no effect on its own. Confocal imaging can provide visual evidence of these interactions with image layering, 3D imaging and enhanced color