Kim Ki-Won, Ha Kee-Yong, Lee Jun-Seok, Nam Suk-Woo, Woo Young-Kyun, Lim Tae-Hong, An Howard S
Department of Orthopedic Surgery, St Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
Spine J. 2009 Apr;9(4):323-9. doi: 10.1016/j.spinee.2008.05.003. Epub 2008 Jul 10.
It was recently demonstrated that the postnatal transition from a notochordal to a fibrocartilaginous nucleus pulposus (NP) is accomplished exogenously by chondrocytes migrating from hyaline cartilage end plates (CEs) into the ectopic notochordal NP region. Although our previous in vivo studies showed evidences for the migration of CE chondrocyte from hyaline CEs into the notochordal NP, it is unknown whether CE chondrocytes of the intervertebral disc (IVD) really have a motile property. In addition, the effect of notochordal cells on this property has not been elucidated.
The purpose of this in vitro study was to demonstrate whether CE chondrocytes of the IVD are capable of migration, and whether there is any biological link between notochordal cells and CE chondrocytes that may regulate the CE chondrocyte migration.
STUDY DESIGN/SETTING: In vitro cell migration assays were performed using rat IVDs.
Notochordal cells and chondrocytes were obtained from the NP and CE tissues, respectively, and were cultured separately. The different numbers of notochordal cells and the supernatant (conditioned medium) that contained soluble factors produced by notochordal cells were used to demonstrate their effects on the migration of CE chondrocytes. Bovine serum albumin (BSA) and lysophosphatidic acid (LPA) were used as negative and positive controls, respectively.
Compared with BSA, LPA, notochordal cells (N=4x, 2x, 1x, and 0.5 x 10(5)), and its conditioned media (unconcentrated and fivefold concentrated) significantly increased migration of CE chondrocytes (p<.05 in all comparisons). Particularly, notochordal cells and its conditioned media increased migration in a number- and concentration-dependent manner, respectively.
This study demonstrates that CE chondrocytes of the IVD are capable of migration and that soluble factors produced by notochordal cells stimulate the migration. These results provide a plausible explanation to the question of why CE chondrocytes of the IVD migrate into the ectopic NP region during the natural transition from the notochordal to fibrocartilaginous NP.
最近有研究表明，出生后从脊索样髓核向纤维软骨性髓核（NP）的转变是由软骨细胞从透明软骨终板（CE）迁移至异位的脊索样NP区域而在外源性完成的。尽管我们之前的体内研究显示了CE软骨细胞从透明软骨终板迁移至脊索样NP的证据，但椎间盘（IVD）的CE软骨细胞是否真的具有运动特性尚不清楚。此外，脊索细胞对这种特性的影响尚未阐明。
本体外研究的目的是证明IVD的CE软骨细胞是否能够迁移，以及脊索细胞与CE软骨细胞之间是否存在可能调节CE软骨细胞迁移的生物学联系。
研究设计/场所：使用大鼠IVD进行体外细胞迁移试验。
分别从NP和CE组织中获取脊索细胞和软骨细胞，并分别进行培养。使用不同数量的脊索细胞以及含有脊索细胞产生的可溶性因子的上清液（条件培养基）来证明它们对CE软骨细胞迁移的影响。分别使用牛血清白蛋白（BSA）和溶血磷脂酸（LPA）作为阴性和阳性对照。
与BSA、LPA相比，脊索细胞（数量分别为4倍、2倍、1倍和0.5×10⁵）及其条件培养基（未浓缩和浓缩5倍）显著增加了CE软骨细胞的迁移（所有比较中p<0.05）。特别是，脊索细胞及其条件培养基分别以数量和浓度依赖性方式增加了迁移。
本研究表明IVD的CE软骨细胞能够迁移，并且脊索细胞产生的可溶性因子刺激了迁移。这些结果为IVD的CE软骨细胞在从脊索样NP向纤维软骨性NP的自然转变过程中迁移至异位NP区域这一问题提供了合理的解释。
