Asano Shuichi, Ito Satoru, Morosawa Mika, Furuya Kishio, Naruse Keiji, Sokabe Masahiro, Yamaguchi Etsuro, Hasegawa Yoshinori
Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan.
Department of Respiratory Medicine and Allergology, Aichi Medical University, Nagakute 480-1195, Japan.
Biochem Biophys Rep. 2018 Sep 22;16:32-38. doi: 10.1016/j.bbrep.2018.09.003. eCollection 2018 Dec.
Activation of airway smooth muscle (ASM) cells plays a central role in the pathophysiology of asthma. Because ASM is an important therapeutic target in asthma, it is beneficial to develop bioengineered ASM models available for assessing physiological and biophysical properties of ASM cells. In the physiological condition , ASM cells are surrounded by extracellular matrix (ECM) and exposed to mechanical stresses such as cyclic stretch. We utilized a 3-D culture model of human ASM cells embedded in type-I collagen gel. We further examined the effects of cyclic mechanical stretch, which mimics tidal breathing, on cell orientation and expression of contractile proteins of ASM cells within the 3-D gel. ASM cells in type-I collagen exhibited a tissue-like structure with actin stress fiber formation and intracellular Ca mobilization in response to methacholine. Uniaxial cyclic stretching enhanced alignment of nuclei and actin stress fibers of ASM cells. Moreover, expression of mRNAs for contractile proteins such as α-smooth muscle actin, calponin, myosin heavy chain 11, and transgelin of stretched ASM cells was significantly higher than that under the static condition. Our findings suggest that mechanical force and interaction with ECM affects development of the ASM tissue-like construct and differentiation to the contractile phenotype in a 3-D culture model.
气道平滑肌（ASM）细胞的激活在哮喘的病理生理学中起着核心作用。由于ASM是哮喘治疗的重要靶点，因此开发可用于评估ASM细胞生理和生物物理特性的生物工程ASM模型具有重要意义。在生理条件下，ASM细胞被细胞外基质（ECM）包围，并受到诸如周期性拉伸等机械应力的作用。我们利用了一种将人ASM细胞嵌入I型胶原凝胶中的三维培养模型。我们进一步研究了模拟潮式呼吸的周期性机械拉伸对三维凝胶中ASM细胞的细胞取向和收缩蛋白表达的影响。I型胶原中的ASM细胞呈现出类似组织的结构，对乙酰甲胆碱有肌动蛋白应激纤维形成和细胞内钙动员反应。单轴循环拉伸增强了ASM细胞核和肌动蛋白应激纤维的排列。此外，拉伸后的ASM细胞中收缩蛋白如α-平滑肌肌动蛋白、钙调蛋白、肌球蛋白重链11和转胶蛋白的mRNA表达明显高于静态条件下。我们的研究结果表明，在三维培养模型中，机械力以及与ECM的相互作用会影响ASM组织样构建体的发育和向收缩表型的分化。
