O'Sullivan Michael J, Gabriel Elizabeth, Panariti Alice, Park Chan Y, Ijpma Gijs, Fredberg Jeffrey J, Lauzon Anne-Marie, Martin James G
1 Meakins-Christie Laboratories, McGill University Health Centre, Montreal, Quebec, Canada; and.
2 Harvard T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts.
Am J Respir Cell Mol Biol. 2017 Dec;57(6):683-691. doi: 10.1165/rcmb.2016-0427OC.
Airway smooth muscle cells (ASMCs) are phenotypically regulated to exist in either a proliferative or a contractile state. However, the influence of other airway structural cell types on ASMC phenotype is largely unknown. Although epithelial cells are known to drive ASM proliferation, their effects on the contractile phenotype are uncertain. In the current study, we tested the hypothesis that epithelial cells reduce the contractile phenotype of ASMCs. To do so, we measured force production by traction microscopy, gene and protein expression, as well as calcium release by Fura-2 ratiometric imaging. ASMCs incubated with epithelial-derived medium produced less force after histamine stimulation. We observed reduced expression of myocardin, α-smooth muscle actin, and calponin within ASMCs after coculture with epithelial cells. Peak calcium release in response to histamine was diminished, and depended on the synthesis of cyclo-oxygenase-1 products by ASM and on prostaglandin E receptors 2 and 4. Together, these in vitro results demonstrate that epithelial cells have the capacity to coordinately reduce ASM contraction by functional antagonism and by reduction of the expression of certain contractile proteins.
气道平滑肌细胞(ASMCs)在表型上受到调控,以增殖或收缩状态存在。然而,其他气道结构细胞类型对ASMC表型的影响在很大程度上尚不清楚。尽管已知上皮细胞会驱动ASM增殖,但其对收缩表型的影响尚不确定。在本研究中,我们检验了上皮细胞会降低ASMCs收缩表型这一假设。为此,我们通过牵引显微镜测量力的产生、基因和蛋白质表达,以及通过Fura-2比率成像测量钙释放。用上皮来源的培养基孵育的ASMCs在组胺刺激后产生的力较小。与上皮细胞共培养后,我们观察到ASMCs中心肌素、α-平滑肌肌动蛋白和钙调蛋白的表达降低。对组胺的峰值钙释放减少,并且依赖于ASM中环氧化酶-1产物的合成以及前列腺素E受体2和4。总之,这些体外结果表明,上皮细胞有能力通过功能拮抗作用和降低某些收缩蛋白的表达来协同减少ASM收缩。