Mechanical and physicochemical regulation of the action of insulin-like growth factor-I on articular cartilage
Mechanical and physicochemical regulation of the action of insulin-like growth factor-I on articular cartilage
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DOI：
10.1006/abbi.2000.1820
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发表时间：
2000-07-01
影响因子：
3.9
通讯作者：
Trippel, SB
中科院分区：
文献类型：
--
作者：
Bonassar, LJ;Grodzinsky, AJ;Trippel, SB
健康关节的发育和维持是一个复杂的过程，涉及许多物理和生物刺激。本研究探讨了胰岛素样生长因子-I（IGF-I）和静态机械加压在关节软骨代谢调节中的相互作用。在存在或不存在0-50%静态压缩的情况下，用浓度为0 - 300 ng/ml的IGF-I处理牛软骨外植体，并测量[H-3]脯氨酸和[S-35]硫酸盐向基质组分中的瞬时和稳态掺入。在平行研究中，软骨外植体用0-300 ng/ml IGF-I在pH范围为6.4 - 7.2的培养基中处理，并测量[H-3]脯氨酸和[S-35]硫酸盐的稳态掺入。通过测量I-125标记的IGF-I进入软骨外植体的摄取来确定50%静态压缩对IGF-I转运的影响。在存在或不存在IGF-I的情况下，静态压缩以剂量依赖性方式降低[H-3]脯氨酸和[S-35]硫酸盐掺入。IGF-I增加[H-3]脯氨酸和[S-35]硫酸盐掺入的剂量依赖性方式在存在或不存在的压缩，但合成代谢的生长因子的影响减少时，组织被压缩50%。软骨外植体对IGF-I的反应在pH6.4的培养基中培养的未应变组织中同样减少，该条件导致与软骨压缩50%时相似的组织内pH。IGF-I刺激软骨外植体的特征时间常数（tau）约为24小时，而通过静态压缩抑制生物合成的tau约为2小时。压缩和用IGF-I处理的样品表明生物合成活性在2小时开始降低，随后在24小时增加。静态压缩并没有改变tau的[I-125]标记的IGF-I运输到软骨中，但在平衡时降低了组织中I-125标记的IGF-I的浓度。(C)北京大学出版社.
The development and maintenance of healthy joints is a complex process involving many physical and biological stimuli. This study investigates the interaction between insulin-like growth factor-I (IGF-I) and static mechanical compression in the regulation of articular cartilage metabolism. Bovine cartilage explants were treated with concentrations of IGF-I from 0 to 300 ng/ml in the presence or absence of 0-50% static compression, and the transient and steady-state incorporation of [H-3]proline and [S-35]sulfate into matrix components were measured. In parallel studies, cartilage explants were treated with 0-300 ng/ml IGF-I at media pH ranging from 6.4 to 7.2 and the steady-state incorporation of [H-3]proline and [S-35]sulfate was measured. The effect of 50% static compression on IGF-I transport was determined by measuring the uptake of I-125-labeled IGF-I into cartilage explants, Static compression decreased both [H-3]proline and [S-35]sulfate incorporation in a dose-dependent manner in the presence or absence of IGF-I. IGF-I increased [H-3]proline and [S-35]sulfate incorporation in a dose-dependent manner in the presence or absence of compression, but the anabolic effect of the growth factor was lessened when the tissue was compressed by 50%. The response of cartilage explants to IGF-I was similarly lessened in unstrained tissue cultured in media at pH 6.4, a condition which results in a similar intratissue pH to that when cartilage is compressed by 50%. The characteristic time constant (tau) for IGF-I stimulation of cartilage explants was approximately 24 h, while tau for inhibition of biosynthesis by static compression was approximately 2 h, Samples which mere both com-pressed and treated with IGF-I demonstrated an initial decrease in biosynthetic activity at 2 h, followed by an increase at 24 h, Static compression did not alter tau for [I-125]labeled IGF-I transport into cartilage but decreased the concentration of I-125-labeled IGF-I in the tissue at equilibrium. (C) 2000 Academic Press.