Smith R L, Rusk S F, Ellison B E, Wessells P, Tsuchiya K, Carter D R, Caler W E, Sandell L J, Schurman D J
School of Medicine, Stanford University, CA 94305-5341, USA.
J Orthop Res. 1996 Jan;14(1):53-60. doi: 10.1002/jor.1100140110.
This study tested the effects of hydrostatic pressure (10 MPa) on adult articular chondrocyte mRNA and extracellular matrix synthesis in vitro. High density primary cultures of bovine chondrocytes were exposed to hydrostatic pressure applied intermittently at 1 Hz or constantly for 4 hours in serum-free medium or in medium containing 1% fetal bovine serum. mRNAs for aggrecan, types I and II collagen, and beta-actin were analyzed by Northern blots and quantified by slot blots. Proteoglycan synthesis was quantified by 35SO4 uptake into cetylpyridinium chloride-precipitable glycosaminoglycans, and cell-associated aggrecan and type-II collagen were detected by immunohistochemical techniques. In serum-free medium, intermittent pressure increased aggrecan mRNA signal by 14% and constant pressure decreased type-II collagen mRNA signal by 16% (p < 0.05). In the presence of 1% fetal bovine serum, intermittent pressure increased aggrecan and type-II collagen mRNA signals by 31% (p < 0.01) and 36% (p < 0.001), respectively, whereas constant pressure had no effect on either mRNA. Intermittent and constant pressure stimulated glycosaminoglycan synthesis 65% (p < 0.001) and 32% (p < 0.05), respectively. Immunohistochemical detection of cell-associated aggrecan and type-II collagen was increased in response to both intermittent and constant pressure. These data support the hypothesis that physiologic hydrostatic pressure directly influences the extracellular matrix metabolism of articular chondrocytes.
本研究检测了流体静压（10兆帕）对成年关节软骨细胞mRNA及体外细胞外基质合成的影响。将高密度原代培养的牛软骨细胞置于无血清培养基或含1%胎牛血清的培养基中，以1赫兹的频率间歇性施加流体静压或持续施加4小时。通过Northern印迹法分析聚集蛋白聚糖、Ⅰ型和Ⅱ型胶原蛋白以及β-肌动蛋白的mRNA，并通过狭缝印迹法定量。通过35SO4掺入十六烷基吡啶氯化物沉淀的糖胺聚糖来定量蛋白聚糖的合成，并通过免疫组织化学技术检测细胞相关的聚集蛋白聚糖和Ⅱ型胶原蛋白。在无血清培养基中，间歇性压力使聚集蛋白聚糖mRNA信号增加14%，持续压力使Ⅱ型胶原蛋白mRNA信号降低16%（p<0.05）。在存在1%胎牛血清的情况下，间歇性压力使聚集蛋白聚糖和Ⅱ型胶原蛋白mRNA信号分别增加31%（p<0.01）和36%（p<0.001），而持续压力对两种mRNA均无影响。间歇性和持续压力分别刺激糖胺聚糖合成65%（p<0.001）和32%（p<0.05）。对细胞相关的聚集蛋白聚糖和Ⅱ型胶原蛋白的免疫组织化学检测显示，间歇性和持续压力均使其增加。这些数据支持了生理性流体静压直接影响关节软骨细胞细胞外基质代谢的假说。
