Hypoxic Culture and Insulin Yield Improvements to Fibrin-Based Engineered Tissue
Hypoxic Culture and Insulin Yield Improvements to Fibrin-Based Engineered Tissue
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DOI：
10.1089/ten.tea.2011.0017
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发表时间：
2012-04-01
影响因子：
4.1
通讯作者：
Tranquillo, Robert T.
中科院分区：
文献类型：
--
作者：
Bjork, Jason W.;Meier, Lee A.;Tranquillo, Robert T.
我们研究了胰岛素补充和低氧培养（2%与20%氧分压）对接种新生人真皮成纤维细胞的纤维蛋白基管状组织结构的胶原沉积和机械性能的影响。这里呈现的结果表明，与常氧（20%氧张力）、非胰岛素补充的对照相比，在低氧条件下培养的具有胰岛素补充的构建体的胶原蛋白密度增加约5倍，极限拉伸强度（UTS）和模量增加超过3倍。此外，胶原蛋白沉积在每个细胞的基础上增加了约四倍。在UTS和胶原蛋白产生方面，以每个细胞为基础，证明了缺氧和胰岛素的相互作用。这种相互作用是由胶原原纤维形成的两个不同过程引起的。蛋白质印迹分析表明，单独补充胰岛素增加Akt磷酸化和联合治疗增加胶原脯氨酰-4-羟化酶。这些分子是胶原沉积的不同调节剂，在胶原原纤维形成的转录和翻译后修饰阶段都有影响，这反过来又增加了组织构建体中的胶原密度。这些发现强调了利用胰岛素补充和低氧培养相结合来增加基于纤维蛋白的工程组织的机械强度和刚度的潜力。
We examined the effect of insulin supplementation and hypoxic culture (2% vs. 20% oxygen tension) on collagen deposition and mechanical properties of fibrin-based tubular tissue constructs seeded with neonatal human dermal fibroblasts. The results presented here demonstrate that constructs cultured under hypoxic conditions with insulin supplementation increased in collagen density by approximately five-fold and both the ultimate tensile strength (UTS) and modulus by more than three-fold compared with normoxic (20% oxygen tension), noninsulin supplemented controls. In addition, collagen deposited on a per-cell basis increased by approximately four-fold. Interaction was demonstrated for hypoxia and insulin in combination in terms of UTS and collagen production on a per-cell basis. This interaction resulted from two distinct processes involved in collagen fibril formation. Western blot analysis showed that insulin supplementation alone increased Akt phosphorylation and the combined treatment increased collagen prolyl-4-hydroxylase. These molecules are distinct regulators of collagen deposition, having an impact at both the transcriptional and posttranslational modification stages of collagen fibril formation that, in turn, increase collagen density in the tissue constructs. These findings highlight the potential of utilizing insulin supplementation and hypoxic culture in combination to increase the mechanical strength and stiffness of fibrin-based engineered tissues.