The effect of two point mutations in GDF-5 on ectopic bone formation in a β-tricalciumphosphate scaffold
The effect of two point mutations in GDF-5 on ectopic bone formation in a β-tricalciumphosphate scaffold
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DOI：
10.1016/j.biomaterials.2010.01.109
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发表时间：
2010-05-01
期刊：
影响因子：
14
通讯作者：
Richter, Wiltrud
中科院分区：
文献类型：
--
作者：
Kasten, Philip;Beyen, Ingo;Richter, Wiltrud
人类生长和分化因子 5 (GDF-5) 的骨诱导性已得到充分证实，但与骨形态发生蛋白 (BMP) 家族的其他成员（如 BMP-2）相比，异位骨的形成量减少。我们假设将 GDF-5 的两个 BMP 受体相互作用残基交换为 BMP-2 中存在的氨基酸（第 453 和 456 位点的蛋氨酸为缬氨酸）可能会提高突变体 GDF-5 的骨形成能力。将突变型GDF-5包被的β-TCP载体的异位骨形成与SCID小鼠中包被相似量(10μg)GDF-5和BMP-2的载体进行比较。四周外植体显示，突变型 GDF-5 中的 ALP 活性比野生型 GDF-5 组高 6 倍（p < 0.0001），与 BMP-2 组相比高 1.4 倍（p < 0.006）。 4 周时，突变型 GDF-5 的组织学骨面积显着高于所有其他组；然而，在第 8 周时，BMP-2 达到了与突变体 GDF-5 类似的新骨形成。 Micro-CT 评估证实，与野生型 GDF-5 相比，突变型 GDF-5 和 BMP-2 组的值更高。总之，突变体 GDF-5 显示出比 GDF-5 更优异的骨形成能力，并且诱导速度更快，最终结果与 BMP-2 相似。因此，突变体 GDF-5 代表了一种有前景的用于骨再生的新 GDF-5 变体，可能通过增加与 BMP-I 型受体的结合亲和力发挥作用。 (C) 2010 Elsevier Ltd. 保留所有权利。
The osteoinductivity of human growth-and-differentiation factor-5 (GDF-5) is well established, but a reduced amount of ectopic bone is formed compared to other members of the bone morphogenetic protein (BMP) family like BMP-2. We hypothesized that swap of two BMP-receptor-interacting residues of GDF-5 to amino acids present in BMP-2 (methionine to valine at the sites 453 and 456) may improve the bone formation capacity of the mutant GDF-5. Heterotopic bone formation of a mutant GDF-5 coated beta-TCP carrier was compared to carriers coated with similar amounts (10 mu g) of GDF-5 and BMP-2 in SCID mice. Four week explants revealed 6-fold higher ALP activity in the mutant GDF-5 versus the wild type GDF-5 group (p < 0.0001) and 1.4-fold higher levels compared to BMP-2 (p < 0.006). Bone area in histology was significantly higher in mutant GDF-5 versus all other groups at 4 weeks; however, at 8 weeks BMP-2 reached a similar neo-bone formation like mutant GDF-5. Micro-CT evaluation confirmed higher values in the mutant GDF-5 and BMP-2 groups compared to wild type GDF-5. In conclusion, the mutant GDF-5 showed superior bone formation capacity than GDF-5, and a faster induction at similar final outcome as BMP-2. Mutant GDF-5 thus represents a promising new GDF-5 variant for bone regeneration possibly acting via an increased binding affinity to the BMP-type I receptor. (C) 2010 Elsevier Ltd. All rights reserved.