Sanguinarine Rapidly Relaxes Rat Airway Smooth Muscle Cells Dependent on TAS2R Signaling.

Sanguinarine Rapidly Relaxes Rat Airway Smooth Muscle Cells Dependent on TAS2R Signaling. Biol Pharm Bull. 2020 May 13;: Authors: Luo M, Yu P, Ni K, Jin Y, Liu L, Li J, Pan Y, Deng L Abstract Excessive contraction of airway smooth muscle cells (ASMCs) is a hallmark feature of asthma. Intriguing, the activation of bitter taste receptor (TAS2R) in ASMCs can relax ASMCs. However, there is a lack of potent TAS2R agonists that can be used in asthma therapies since those tested agonists cannot relax ASMCs at the dose below a few hundred micromolar. Considering that sanguinarine (SA) is a bitter substance often used in small doses for the treatment of asthma in folk medicine, the present study was to determine the rapid relaxation effect of SA on ASMCs and to reveal the underlying mechanisms associated with TAS2R signaling. Here, cell stiffness, traction force, calcium signaling, cAMP levels, and the mRNA expression were evaluated by using optical magnetic twisting cytometry, traction force microscopy, Fluo-4/AM labeling, ELISA, and qRT-PCR, respectively. We found that 0.5 μM SA immediately decreased cell stiffness and traction force, which is comparable with the effect of 5 μM isoproterenol. In addition, 0.5 μM SA immediately increased intracellular free calcium concentration ([Ca2+]i) and decreased the mRNA expression of contractile proteins such as calponin and α-smooth muscle actin after the treatment for 24 h. Furthermore, SA-media...
Source: Biological and Pharmaceutical Bulletin - Category: Drugs & Pharmacology Authors: Tags: Biol Pharm Bull Source Type: research