Halper J, Griffin A, Hu W, Jung C, Zhang J, Pan H, Kisaalita W S, Foutz T L, Frazier K S
The Soft Tissue Center, Department of Pathology, The University of Georgia, Athens, GA 30602, USA.
J Musculoskelet Neuronal Interact. 2005 Mar;5(1):53-63.
Weight-bearing tendons in many species, including humans, chickens and horses, are prone to failure, in many cases without a discernible cause. The normal function of the tendon depends on the proper assembly of fibrils of type I collagen, the main structural component of the tendon. We studied the effect of in vitro culture, temperature (37 degrees C vs. 43 degrees C) and wounding on the expression of mRNAs for several collagen regulators, transforming growth factor beta (TGF(beta)), heat shock protein 47 (Hsp47) and connective tissue growth factor (CTGF), in chicken embryonic gastrocnemius tendon explants. The expression of mRNAs for TGF(beta) and Hsp47, a chaperone of collagen assembly, remained strong during the first day of in vitro culture, but then it decreased, slightly more at higher temperature. Additional injury in selected tendons had no significant effect on the levels of TGF(beta) and Hsp47 mRNAs. Likewise, the level of immunostained type I procollagen also decreased with the length of culture. The expression of CTGF gradually increased from 0 at the time of tendon removal with the duration of culture to strong after three days of culture when the expression of TGF(beta) and Hsp47 was low. We conclude that in vitro culture over the period of several days rather than an increase in temperature or additional wounding decreases the expression of TGF(beta), Hsp47 and type I procollagen and increases the expression of CTGF.
包括人类、鸡和马在内的许多物种的负重肌腱都容易出现损伤，在很多情况下原因不明。肌腱的正常功能取决于I型胶原蛋白纤维的正确组装，I型胶原蛋白是肌腱的主要结构成分。我们研究了体外培养、温度（37摄氏度与43摄氏度）和创伤对鸡胚腓肠肌腱外植体中几种胶原蛋白调节因子、转化生长因子β（TGF(β)）、热休克蛋白47（Hsp47）和结缔组织生长因子（CTGF）的mRNA表达的影响。TGF(β)和Hsp47（胶原蛋白组装的伴侣蛋白）的mRNA表达在体外培养的第一天仍然很强，但随后下降，在较高温度下下降得稍多。对选定肌腱的额外损伤对TGF(β)和Hsp47 mRNA水平没有显著影响。同样，免疫染色的I型前胶原水平也随着培养时间的延长而下降。CTGF的表达从肌腱取出时的0逐渐增加，随着培养时间的延长，在培养三天后当TGF(β)和Hsp47表达较低时变得很强。我们得出结论，几天的体外培养而非温度升高或额外创伤会降低TGF(β)、Hsp47和I型前胶原的表达，并增加CTGF的表达。
