Joint Department of Biomedical Engineering at University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, North Carolina.
Molecular Cardiology, Cleveland Clinic, Ohio.
J Tissue Eng Regen Med. 2018 Dec;12(12):2277-2286. doi: 10.1002/term.2760. Epub 2018 Nov 22.
Corin has been studied extensively within the vascular system and is known to regulate blood pressure. We have shown that corin is one of the most highly upregulated genes during osteogenic differentiation of human adipose-derived stem cells (hASCs). This study tested the hypothesis that, through modulation of angiogenic signalling pathways, corin is a critical regulator of osteogenic differentiation and endochondral ossification. In vitro, corin expression in hASC was suppressed via siRNA knockdown and vascular endothelial growth factor A (VEGF-A) expression was quantified via reverse transcription polymerase chain reaction. In vivo, a murine corin knockout model (female, 10 weeks) was used to determine the effect of corin deficiency on long bone development. Wild-type and corin knockout long bones were compared via haematoxylin and eosin staining to assess tissue characteristics and cellular organization, three-point bending to assess mechanical characteristics, and immunohistochemistry to visualize VEGF-A expression patterns. Corin knockdown significantly (p < 0.05) increased VEGF-A mRNA expression during osteogenic differentiation. In vivo, corin knockout reduced tibial growth plate thickness (p < 0.01) and severely diminished the hypertrophic region. Corin knockout femurs had significantly increased stiffness (p < 0.01) and maximum loads (p < 0.01) but reduced postyield deflections (p < 0.01). In corin knockout mice, VEGF-A expression was increased near the growth plate but was reduced throughout the tibial shaft and distal head of the tibiae. This is the first study to show that corin is a key regulator of bone development by modulation of VEGF-A expression. Further elucidation of this mechanism will aid in the development of optimized bone tissue engineering and regenerative medicine therapies.
科林在血管系统中得到了广泛的研究，已知其可调节血压。我们已经表明，在人脂肪来源干细胞（hASC）的成骨分化过程中，科林是上调最明显的基因之一。本研究通过调节血管生成信号通路，检验了科林是成骨分化和软骨内骨化的关键调节因子这一假说。在体外，通过 siRNA 敲低抑制 hASC 中的科林表达，并通过逆转录聚合酶链反应定量测定血管内皮生长因子 A（VEGF-A）的表达。在体内，使用鼠科林敲除模型（雌性，10 周）来确定科林缺乏对长骨发育的影响。通过苏木精和伊红染色比较野生型和科林敲除长骨，以评估组织特征和细胞组织，三点弯曲评估力学特性，并通过免疫组织化学可视化 VEGF-A 表达模式。科林敲低显著（p<0.05）增加了成骨分化过程中的 VEGF-A mRNA 表达。在体内，科林敲除减少了胫骨生长板厚度（p<0.01），严重减少了肥大区。科林敲除股骨的刚度显著增加（p<0.01），最大载荷增加（p<0.01），但屈服后挠度减小（p<0.01）。在科林敲除小鼠中，VEGF-A 表达在生长板附近增加，但在胫骨骨干和胫骨远端头部减少。这是第一项表明科林通过调节 VEGF-A 表达是骨发育的关键调节因子的研究。进一步阐明这一机制将有助于优化骨组织工程和再生医学疗法的发展。
