Substrate stiffness affects sarcomere and costamere structure and electrophysiological function of isolated adult cardiomyocytes.
Substrate stiffness affects sarcomere and costamere structure and electrophysiological function of isolated adult cardiomyocytes.
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基底硬度会影响离体成体心肌细胞的肌节和肋膜结构以及电生理功能。
DOI：
10.1016/j.carpath.2012.10.003
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发表时间：
2013-05
影响因子：
3.7
通讯作者：
Stegemann, Jan P.
中科院分区：
文献类型：
--
作者：
Galie, Peter A.;Khalid, Nashmia;Carnahan, Kelly E.;Westfall, Margaret V.;Stegemann, Jan P.
机械环境是心肌细胞功能的关键调节因素。我们研究了底物硬度对成年大鼠心肌细胞肌节和胞壁组织的作用，并进一步检测了由此导致的细胞缩短和钙动力学的变化。将分离的成年大鼠心肌细胞接种于硬度分别为255kPa1、117kPa、27kpA和7kpA的层粘连蛋白包被的聚二甲基硅氧烷基质上48h，用免疫荧光成像法和免疫印迹法检测α-肌动蛋白和β-1整合素的表达水平，并用磷酸酶抑制剂Calyculin A处理心肌细胞。定量RT-PCR法检测关键结构蛋白(α-肌动蛋白、α7整合素、β1整合素、纽蛋白)的表达水平。分别于术后2、24、48h测定肌节缩短和钙动力学变化。所有底物上的整体心肌细胞形态相似。然而，只有在最硬的(255 Kpa)和最柔顺的(7kpa)基质上才能观察到组织良好的肌节结构。细胞中的α-Actinin水平在所有底物上是相同的，而结构蛋白的信息水平在中等硬度的底物上上调。抑制磷酸酶活性阻止了收缩结构的降解，但改变了整个心肌细胞的形态。缩短和钙动力学也依赖于基质硬度，但两者之间没有明确的因果关系。细胞外基质刚性可以影响成年心肌细胞的结构重塑，以及由此产生的收缩活动。这些发现阐明了心肌纤维化时心肌细胞功能的变化，并可能提示心肌特异性磷酸酶作为治疗干预的靶点。
The mechanical environment is a key regulator of function in cardiomyocytes. We studied the role of substrate stiffness on the organization of sarcomeres and costameres in adult rat cardiomyocytes, and further examined the resulting changes in cell shortening and calcium dynamics. Cardiomyocytes isolated from adult rats were plated on laminin-coated polydimethylsiloxane substrates of defined stiffness (255 kPa, 117 kPa, 27 kPa, and 7 kPa) for 48 h. Levels of α-actinin and β1 integrins were determined by immunofluoresence imaging and immunoblotting, both in the absence and presence of the phosphatase inhibitor calyculin A. Quantitative RT-PCR was used to measure message levels of key structural proteins (α-actinin, α7 integrin, β1 integrin, vinculin). Sarcomere shortening and calcium dynamics were measured at 2, 24, and 48 hours. Overall cardiomyocyte morphology was similar on all substrates. However, well organized sarcomere structures were observed on only the stiffest (255 kPa) and the most compliant (7 kPa) substrates. Levels of α-actinin in cells were the same on all substrates, while message levels of structural proteins were upregulated on substrates of intermediate stiffness. Inhibition of phosphatase activity blocked the degradation of contractile structures, but altered overall cardiomyocyte morphology. Shortening and calcium dynamics also were dependent on substrate stiffness, however there was no clear causative relationship between the phenomena. Extracellular matrix stiffness can affect structural remodeling by adult cardiomyocytes, and the resulting contractile activity. These findings illuminate changes in cardiomyocyte function in cardiac fibrosis, and may suggest cardiac-specific phosphatases as a target for therapeutic intervention
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影响因子：
2.4
作者：
Jacot JG;Martin JC;Hunt DL
通讯作者：
Hunt DL
影响因子：
4.8
作者：
Ibrahim, Michael;Al Masri, Abeer;Terracciano, Cesare M. N.
通讯作者：
Terracciano, Cesare M. N.
影响因子：
4.8
作者：
Engelhardt, S;Boknik, P;Hein, L
通讯作者：
Hein, L
影响因子：
3.8
作者：
Bhana, Bashir;Iyer, Rohin K.;Radisic, Milica
通讯作者：
Radisic, Milica
DOI：
10.1126/science.1171643
发表时间：
2009-06-26
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Discher DE;Mooney DJ;Zandstra PW
通讯作者：
Zandstra PW