Induced elastic matrix deposition within three-dimensional collagen scaffolds.
Induced elastic matrix deposition within three-dimensional collagen scaffolds.
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DOI：
10.1089/ten.tea.2010.0749
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发表时间：
2011-08
影响因子：
--
通讯作者：
L. Venkataraman;A. Ramamurthi
中科院分区：
文献类型：
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作者：
L. Venkataraman;A. Ramamurthi
周期性扩张的弹性动脉的结构稳定性和血管平滑肌细胞（SMC）的健康功能由完整的弹性基质及其主要蛋白质弹性蛋白的存在来维持。在几种血管疾病中发生的弹性基质的加速降解，加上成人SMC再生丢失的弹性蛋白的能力差，因此可能对血管稳态产生不利影响。类似地，组织工程化弹性基质结构的努力受到我们不能诱导成体细胞合成原弹性蛋白前体并将它们交联成天然弹性基质的结构模拟物的限制，特别是在SMC/成纤维细胞主要存款胶原丰富的工程化构建体中。在这项研究中，我们已经表明，转化生长因子-β 1（TGF-β1）和透明质酸寡聚体（HA-o）协同增强弹性基质沉积的成年大鼠主动脉平滑肌细胞（RASMC）接种在非弹性，静态加载的三维凝胶，由非弹性I型胶原蛋白组成。虽然与非添加剂对照培养物相比，实验病例中的原弹性蛋白的产生在3周内没有实质性增加，但我们观察到基质弹性蛋白沉积的显著增加;接受最低剂量的TGF-β1和相应剂量的HA-α的构建体中的可溶性基质弹性蛋白，以及与升高的赖氨酰氧化酶蛋白量对应的最高剂量的不溶性基质。然而，尽管有弹性诱导，在所有实验情况下，总体基质产量仍然很差。在所有提供的剂量下，这些因子降低了基质金属蛋白酶（MMP）-9的产生，尤其是活性酶，尽管MMP-2水平仅在与较高剂量的TGF-β1培养的构建体中降低。免疫荧光显示胶原结构内的弹性纤维是不连续的，除了结构的边缘。Von Kossa染色显示所有病例均无钙化沉积。本研究证实了在胶原环境中，利用TGF-β1和HA-α诱导成人RASMC合成基质弹性蛋白的益处超过非添加剂对照，胶原环境本身并不有利于弹性蛋白生成。
The structural stability of a cyclically distending elastic artery and the healthy functioning of vascular smooth muscle cells (SMCs) within are maintained by the presence of an intact elastic matrix and its principal protein, elastin. The accelerated degradation of the elastic matrix, which occurs in several vascular diseases, coupled with the poor ability of adult SMCs to regenerate lost elastin, can therefore adversely impact vascular homeostasis. Similarly, efforts to tissue engineer elastic matrix structures are constrained by our inability to induce adult cells to synthesize tropoelastin precursors and to crosslink them into architectural mimics of native elastic matrices, especially within engineered constructs where SMCs/fibroblasts primarily deposit collagen in abundance. In this study, we have shown that transforming growth factor-beta1 (TGF-β1) and hyaluronan oligomers (HA-o) synergistically enhance elastic matrix deposition by adult rat aortic SMCs (RASMCs) seeded within nonelastogenic, statically loaded three-dimensional gels, composed of nonelastogenic type-I collagen. While there was no substantial increase in production of tropoelastin within experimental cases compared to the nonadditive control cultures over 3 weeks, we observed significant increases in matrix elastin deposition; soluble matrix elastin in constructs that received the lowest doses of TGF-β1 with respective doses of HA-o, and insoluble matrix at the highest doses that corresponded with elevated lysyl-oxidase protein quantities. However, despite elastogenic induction, overall matrix yields remained poor in all experimental cases. At all provided doses, the factors reduced the production of matrix metalloproteinases (MMP)-9, especially the active enzyme, though MMP-2 levels were lowered only in constructs cultured with the higher doses of TGF-β1. Immuno-fluorescence showed elastic fibers within the collagen constructs to be discontinuous, except at the edges of the constructs. Von Kossa staining revealed no calcific deposits in any of the cases. This study confirms the benefits of utilizing TGF-β1 and HA-o in inducing matrix elastin synthesis by adult RASMCs over nonadditive controls, within a collagenous environment, that is not inherently conducive to elastogenesis.