Mechanical loading regulates protease production by fibroblasts in three-dimensional collagen substrates
Mechanical loading regulates protease production by fibroblasts in three-dimensional collagen substrates
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DOI：
10.1046/j.1524-475x.2000.00226.x
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发表时间：
2000-05-01
影响因子：
2.9
通讯作者：
Brown, RA
中科院分区：
文献类型：
--
作者：
Prajapati, RT;Chavally-Mis, B;Brown, RA
机械负荷对于组织形成和重塑非常重要，特别是在伤口修复中。本研究的目的是测量控制负荷对成纤维细胞释放细胞外基质蛋白酶活性的影响。成纤维细胞填充的胶原蛋白晶格通过纳入培养系统的计算机控制单元（张力培养力监视器）承受外部循环负载。将循环加载与未拉伸和静态加载的凝胶（系留内源收缩）进行比较。监测一系列蛋白酶活性的总体变化（主要通过酶谱法）作为对这些负荷的细胞机械反应的测量。在静态负载下，24 小时和 48 小时时，产生的基质金属蛋白酶-2 是基质金属蛋白酶-9 的 2.5 倍和 13 倍。循环加载时，总基质金属蛋白酶 9 增加 37 倍。总基质金属蛋白酶-3和尿激酶纤溶酶原激活剂活性在循环负荷下显着降低，而组织型纤溶酶原激活剂活性增加。与较硬基质（胶原海绵）上的细胞反应进行比较，发现了类似的基质金属蛋白酶对负载的反应，但水平大大降低（负载时基质金属蛋白酶9刺激4-6倍），显示了基质顺应性对这种机械响应的重要性。总之，三维胶原蛋白晶格中成纤维细胞的生理机械负荷引起基质修饰蛋白酶发生复杂且实质性的变化。这些变化表明细胞在可比较的蛋白酶活性的表达之间切换，主要影响与迁移或更普遍的细胞外基质重塑相关的细胞-基质相互作用。
Mechanical loading is important in tissue formation and remodelling, notably in wound repair. The aim of this study was to measure the effects of controlled loading on the release of extracellular matrix protease activities by fibroblasts. Fibroblast populated collagen lattices were subjected to external cyclical loads through a computer controlled unit incorporated into a culture system, a tensioning-Culture Force Monitor. Cyclical loading was compared to untensioned and statically loaded gels (tethered endogenous contraction). Overall changes in a range of protease activities were monitored (chiefly by zymography) as measures of the cyto-mechanical response to these loads. Under static load, 2.5- and 13-fold more matrix metalloproteinase-2 was produced than matrix metalloproteinase-9, at 24 and 48 hours. Total matrix metalloproteinase-9 increased 37 fold on cyclical loading. Total matrix metalloproteinase-3 and urokinase plasminogen activator activities were dramatically reduced on cyclical loading while tissue type plasminogen activator activity was increased. Comparison with cell responses on stiffer substrates (collagen sponges) identified similar matrix metalloproteinase responses to load, but at much reduced levels (4-6 fold matrix metalloproteinase-9 stimulation on loading), showing the importance of matrix compliance to this mechano-response. In conclusion, physiological mechanical loading of fibroblasts in three dimensional collagen lattices elicited complex and substantial changes in matrix modifying proteases. These changes suggest that cells switch between expression of comparable protease activities mainly influencing cell-matrix interactions associated with migration or more generalized extracellular matrix remodelling.