期刊
CONNECTIVE TISSUE RESEARCH
卷 56, 期 3, 页码 212-218出版社
INFORMA HEALTHCARE
DOI: 10.3109/03008207.2014.1001383
关键词
Chondrocyte; cofilin; F-actin remodeling; mechanical refractory period; VEGF
资金
- National Natural Science Foundation of China [81171461]
- Science Foundation of Hunan Provincial Science and Technology Department [2012WK3001]
- Natural Science Foundation of Hunan Province [13JJ2013]
Purpose: Mechanical stimulation, a crucial factor for maintaining the cartilaginous phenotype and promoting the chondrogenesis, has been widely used in autologous chondrocyte transplantation. This study was designed to investigate a novel concept of mechanical refractory period of chondrocytes after dynamic hydrostatic pressure (dHP). Materials and methods: dHP protocols (0.1 Hz, 2 MPa) were applied. The variation in type II collagen (Col II) expression induced by each dHP unit was measured. The dynamic remodeling of F-actin during the mechanical protocols was observed morphologically and mechanically by laser confocal microscopy and optical magnetic twisting cytometry (OMTC), respectively. About 20 ng/ml VEGF was used to stabilize the F-actin and restrain the mechanical refractory period. Results: Compared with the remarkable increase of Col II (16-fold) induced by the initial dHP unit, the chondrocytes entered a mechanical refractory period and the second unit hardly elevated Col II expression (only 2.9-fold). This refractory period recovered partially within 2 h. The uniform, parallel, and coarse fibers of F-actin before dHP became thin, sparse, and disordered, and the cell stiffness decreased concomitantly. The variations in both the morphology and the mechanical property of F-actin were highly synchronous to the mechanical refractory period and recovered in a time-dependent manner. VEGF postponed the appearance of this refractory period and maintained the high expression of Col II by VEGF/p38/MAPKAPK-2/LIMK/cofilin pathway. Conclusion: A mechanical refractory period of chondrocytes has been discovered and defined in this study. The F-actin depolymerization is the putative mechanism, and this refractory period can be postponed by VEGF-induced F-actin stabilization.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据