Mechanical load stimulates expression of novel genes in vivo and in vitro in avian flexor tendon cells
Mechanical load stimulates expression of novel genes in vivo and in vitro in avian flexor tendon cells
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DOI：
10.1053/joca.1998.0169
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发表时间：
1999-01-01
影响因子：
7
通讯作者：
Miller, L
中科院分区：
文献类型：
--
作者：
Banes, AJ;Horesovsky, G;Miller, L
目的：我们的实验旨在验证肌腱细胞在体外对外加应变的反应可能不同于在体的假设。设计：我们测试了运动鸡的整个肌腱以及体外机械应变下的分离表面(TSC)和肌腱内(TIF)的细胞。我们假设肌腱细胞在体内和体外对机械负荷有不同的基因表达。方法：采用体内运动模型，鸡在急性负荷状态下在跑步机上跑步1h 45min，其余时间休息至6h。用差异显示技术分析基因表达。此外，分离的禽趾深屈肌TSC和TIF细胞在1 Hz、平均伸长5%的条件下循环拉伸6h，+/-PDGF-BB、IGF-I、TGF-β1、PTH、雌激素、PGE(2)或不加药和/或不加负荷。结论：无论加或不加生长因子和激素处理的负荷均可诱导新基因和一些已知基因的表达，这些基因对肌腱细胞是新的。我们的结论是，对体内和体外机械负载细胞中基因表达的研究将导致发现新的重要标记蛋白，这些标记蛋白可能会提供线索，揭示在一种条件下具有保护作用，在另一种条件下具有破坏性的阳性和阴性细胞株反应。
Objective: Our experiments were designed to test the hypothesis that tendon cells might respond differently to applied strain in vitro than in vivo.Design: We tested cells in whole tendons from exercised chickens and from isolated surface (TSC) and internal tendon (TIF) in vitro that were subjected to mechanical strain. We hypothesized that tendon cells differentially express genes in response to mechanical loading in vivo and in vitro.Methods: We utilized an in-vivo exercise model in which chickens were run on a treadmill in an acute loading regime for 1 h 45 min with the balance of time at rest to 6 h total time. Gene expression was analyzed by a differential display technique. In addition, isolated avian flexor digitorum profundus TSC and TIF cells were subjected to cyclic stretching at 1 Hz, 5% average elongation for 6 h, +/- PDGF-BB, IGF-I, TGF-beta 1, PTH, estrogen, PGE(2), or no drug and/or no load. mRNA was then collected and samples were subjected to differential display analysis.Conclusions: Load with or without growth factor and hormone treatments induced expression of novel genes as well as some known genes that were novel to tendon cells. We conclude that the study of gene expression in mechanically loaded cells in vivo and in vitro will lead to the discovery of novel and important marker proteins that may yield clues to positive and negative cell strain responses that are protective under one set of conditions and destructive under another.