Expression of matrix metalloproteinases 2 and 9 in regenerating skeletal muscle:: A study in experimentally injured and mdx muscles
Expression of matrix metalloproteinases 2 and 9 in regenerating skeletal muscle:: A study in experimentally injured and mdx muscles
复制标题
DOI：
10.1006/dbio.1998.9107
复制
发表时间：
1999-01-01
影响因子：
2.7
通讯作者：
Alameddine, HS
中科院分区：
文献类型：
--
作者：
Kherif, S;Lafuma, C;Alameddine, HS
基质金属蛋白酶（MMP）协同降解细胞外基质（ECM）的所有组分。骨骼肌变性和再生过程中ECM的重塑表明肌肉再生过程中基质降解活性的严格调节。本研究旨在探讨MMP-2和MMP-9在正常肌肉中的表达及其在再生过程中的调控。我们进一步研究了C2 C12肌源性细胞系的分泌。使用两种肌肉变性-再生模型：（1）正常肌肉，其中通过心脏毒素注射实验性地诱导坏死;（2）mdx肌肉，其表现出局灶性肌纤维坏死的复发迹象，随后成功再生。基质金属蛋白酶进行了研究，其自由活动进行了定量使用H-3标记的明胶底物和mRNA表达，然后通过北方杂交。通过常规形态学方法分析肌肉变性再生，并在肌肉切片上进行原位杂交以鉴定表达这些MMPs的细胞。结果表明，MMP-2，而不是MMP-9的表达，是组成在正常肌肉。在损伤后，MMP-2的活性形式短暂增加，而MMP-9在24小时内被诱导并保持存在数天。游离明胶分解活性的定量测定显示出渐进和稳定的增加，在伤后7天达到高潮，并缓慢恢复到正常水平。在成年mdx小鼠中，表达MMP-2和MMP-9的前体和活性形式。北方印迹结果支持这些发现。C2 C12条件培养基的酶谱显示肌源性细胞产生MMP-2。通过原位杂交，我们定位MMP-9 mRNA在炎症细胞和假定的活化卫星细胞在受伤的肌肉。我们的数据允许MMP-2和MMP-9的原和/或活性形式的差异表达与变性再生过程的不同阶段的相关性：MMP-9的表达与炎症反应有关，可能与卫星细胞的活化有关，而MMP-2的活化与新肌纤维的再生有关。(C)北京：科学出版社.
Matrix metalloproteinases (MMPs) cooperatively degrade all components of the extracellular matrix (ECM). Remodeling of ECM during skeletal muscle degeneration and regeneration suggests a tight regulation of matrix-degrading activity during muscle regeneration. In this study, we investigated the expression of MMP-2 and MMP-9, in normal muscles and their regulation during regeneration process. We further investigated their secretion by C2C12 myogenic cell line. Two models of muscle degeneration-regeneration were used: (1) normal muscles in which necrosis was experimentally induced by cardiotoxin injection; (2) mdx muscles which exhibit recurrent signs of focal myofiber necrosis followed by successful regeneration. MMPs were studied by zymography; their free activity was quantified using H-3-labeled gelatin substrate and mRNA expression was followed by Northern hybridization. Muscle degeneration-regeneration was analyzed by conventional morphological methods and in situ hybridization was performed on muscle sections to identify the cells expressing these MMPs. Results show that MMP-2, but not MMP-9 expression, is constitutive in normal muscles. Upon injury, the active form of MMP-2 is transiently increased, whereas MMP-9 is induced within 24 h and remains present for several days. Quantitative assays of free gelatinolytic activity show a progressive and steady increase that culminates at 7 days postinjury and slowly returns to normal levels. In adult mdx mice, both pro and active forms of MMP-2 and MMP-9) are expressed. Northern blot results support these findings. Zymography of C2C12-conditioned medium shows that myogenic cells produce MMP-2. By in situ hybridization we localized MMP-9 mRNA in inflammatory cells and putative activated satellite cells in injured muscles. Our data allow the correlation of the differential expression of pro and/or active forms of MMP-2 and MMP-9 with different stages of the degeneration-regeneration process: MMP-9 expression is related to the inflammatory response and probably to the activation of satellite cells, whereas MMP-2 activation is concomitant with the regeneration of new myofibers. (C) 1999 Academic Press.