S022024 基質剛性が単離腱細胞の牽引力に与える影響([S02202]細胞および分子のマイクロ・ナノスケール解析(2))

Abstract

Tendon is subjected to dynamic mechanical loading in vivo. Effects of cyclic tensile loading on tenocyte metabolism have been characterized well. However, the relationship between cell metabolism and internal tension within cytoskeleton has not been studied in detail. Elastic micropillars made from silicone elastomer (PDMS) have been proposed to measure cellular traction forces which reflect cytoskeletal tension. Micropillar substrates with three different elastic moduli were prepared by changing the height of the pillars. After tenocytes were seeded on each substrate for 24 hours, traction forces were determined. Real-time qPCR was also performed to examine the expressions of type I collagen (anabolic gene) and MMP-1 (catabolic gene) mRNA from tenocytes on these substrates. It was found that there were significant increases in cellular traction forces with the elastic modulus of micropillar substrates. Although there were no significant differences in the expression level of type I collagen among three substrates, increases were observed in the expression level of MMP-1 with decreases in the elastic modulus of substrate. This may indicate that intracellular cytoskeletal tension strongly influences tenocyte catabolism rather than anabolism.