Biochemical and immuno-histochemical localization of type IIA procollagen in annulus fibrosus of mature bovine intervertebral disc.
Biochemical and immuno-histochemical localization of type IIA procollagen in annulus fibrosus of mature bovine intervertebral disc.
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DOI：
10.1016/j.mbplus.2021.100077
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发表时间：
2021-12
影响因子：
--
通讯作者：
Fernandes RJ
中科院分区：
文献类型：
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作者：
McAlinden A;Hudson DM;Fernandes AA;Ravindran S;Fernandes RJ
为了使下一代组织工程构建和再生医学在临床上取得成功，必须完全确定这些修复技术寻求恢复的组织的基本生物学和细胞外基质组成。使用最新的试剂加上久经考验的方法，我们继续发现以前未被发现的成熟椎间盘结构蛋白。在这项研究中，我们表明，“胚胎”IIA型前胶原亚型（含有富含半胱氨酸的氨基前肽）是生化检测在小牛和成熟的steer尾椎间盘纤维环，但不是在髓核IIB亚型主要是本地化。具体而言，三螺旋IIA型前胶原亚型免疫定位于内部纤维环的外缘。三螺旋加工的II型胶原仅位于板层间区域内，IIA型前胶原位于板层内区域。IIA型前胶原所在区域的α1（II）胶原链的质谱分析显示脯氨酸-944高度3-羟基化，这是一种与髓核中的薄胶原纤维相关的翻译后修饰。研究结果表明，IIA型前胶原在纤维环的选定区域中的小直径原纤维可能有助于I型-II型胶原过渡区内胶原束的组织和结构特性。
For next generation tissue-engineered constructs and regenerative medicine to succeed clinically, the basic biology and extracellular matrix composition of tissues that these repair techniques seek to restore have to be fully determined. Using the latest reagents coupled with tried and tested methodologies, we continue to uncover previously undetected structural proteins in mature intervertebral disc. In this study we show that the “embryonic” type IIA procollagen isoform (containing a cysteine-rich amino propeptide) was biochemically detectable in the annulus fibrosus of both calf and mature steer caudal intervertebral discs, but not in the nucleus pulposus where the type IIB isoform was predominantly localized. Specifically, the triple-helical type IIA procollagen isoform immunolocalized in the outer margins of the inner annulus fibrosus. Triple helical processed type II collagen exclusively localized within the inter-lamellae regions and with type IIA procollagen in the intra-lamellae regions. Mass spectrometry of the α1(II) collagen chains from the region where type IIA procollagen localized showed high 3-hydroxylation of Proline-944, a post-translational modification that is correlated with thin collagen fibrils as in the nucleus pulposus. The findings implicate small diameter fibrils of type IIA procollagen in select regions of the annulus fibrosus where it likely contributes to the organization of collagen bundles and structural properties within the type I-type II collagen transition zone.