Role of FFAR1/4 in excitation-contraction coupling in human airway smooth cell. Asthma is an airway disease characterized by airway hyperresponsiveness (AHR), inflammation and remodeling. This project is about the role of free fatty acid receptors FFAR1 and FFAR4 in human ASM cells to regulate AHR. Our findings show that FFAR1 agonists attenuate MLC phosphorylation, a biochemical marker of HASM cell shortening, and therefore has the potential to broncho-protect human airways from hyperreactivity.