The use of fluorescence correlation spectroscopy to monitor cell surface β2‐adrenoceptors at low expression levels in human embryonic stem cell‐derived cardiomyocytes and fibroblasts

The importance of cell phenotype in determining the molecular mechanisms underlying β2-adrenoceptor (β2AR) function has been noted previously when comparing responses primary cells and recombinant model lines. Here, we have generated haplotype-specific SNAP-tagged β2AR human embryonic stem (ES) lines applied fluorescence correlation spectroscopy (FCS) to study surface receptors progenitor differentiated fibroblasts cardiomyocytes. FCS was able quantify number diffusion both ES-derived cardiomyocytes CRISPR/Cas9 genome-edited HEK293T cells, where expression level too low detect using standard confocal microscopy. These studies demonstrate power investigating β2ARs at very levels often seen endogenously expressing cells. Furthermore, use ES technology combination with allowed us that internalize response formoterol-stimulation but not following their differentiation into fibroblasts. This indicates process agonist-induced receptor internalization is strongly influenced by this may important implications for drug treatment long-acting agonists.