Cellular force assay detects altered contractility caused by a nephritis‐associated mutation in nonmuscle myosin IIA

• Published in: Development, growth & differentiation growth & differentiation, 2017-06, Vol.59 (5), p.423-433
• Main Authors: Fukuda, Shota P., Matsui, Tsubasa S., Ichikawa, Takafumi, Furukawa, Taichi, Kioka, Noriyuki, Fukushima, Shuichiro, Deguchi, Shinji
• Format: Article
• Language: English
• Subjects: Amino Acid Substitution; Cell Proliferation; cellular force assay; cellular traction force; Contractility; Data processing; HEK293 Cells; Humans; Kidney transplantation; mechanobiology; Molecular Motor Proteins - genetics; Molecular Motor Proteins - metabolism; Mutation; MYH9 disorders; MYH9 gene; Myosin; Myosin Heavy Chains - genetics; Myosin Heavy Chains - metabolism; Nephritis; Nephritis - genetics; Nephritis - metabolism; nonmuscle myosin II; Pathogenesis; Point Mutation; Silicones
• ISSN: 0012-1592; 1440-169X
• DOI: 10.1111/dgd.12379

Recent progress in understanding the essential roles of mechanical forces in regulating various cellular processes expands the field of biology to one where interdisciplinary approaches with engineering techniques become indispensable. Contractile forces or contractility—inherently present in proliferative cells due to the activity of ubiquitous nonmuscle myosin II (NMII)—are one of such mechano‐regulators, but because NMII works downstream of diverse signaling pathways, it is often difficult to predict how the inherent cellular forces change upon perturbations to particular molecules. Here, we determine whether the contractility of individual cells is upregulated or downregulated based on an assay analyzing specific deformations of silicone gel substrates. We focus on the effect of mutations in the human MYH9 gene that encodes NMIIA, which have been implicated in the pathogenesis of various diseases including nephritis. Our assay equipped with a high‐throughput data analysis capability reveals that a point mutation of E1841K but not I1816V significantly reduces the magnitude of the endogenous forces of human embryonic kidney (HEK293) cells. Given the increasingly recognized roles of the endogenous forces as a critical mechano‐regulator as well as that no apparent morphological changes were induced to cells even by introducing the mutations, our findings suggest a possibility that the detected reduction in the force magnitude at the individual cellular level may underlie the pathogenesis of the kidney disease. Mutations in nonmuscle myosin IIA have been implicated in pathogenesis of various diseases including nephritis. Our assay detected changes in cellular endogenous forces due to one of the reported mutations, thus suggesting that the downregulation of the physical properties may underlie the pathogenesis of the diseases.