Department of Clinical Chemistry and Transfusion Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden.
Spine (Phila Pa 1976). 2012 Apr 20;37(9):722-32. doi: 10.1097/BRS.0b013e318231c2f7.
Descriptive experimental study performed in rabbits of 2 age groups.
To study and investigate presence of prechondrocytic cells and cell migration routes (MR) in the intervertebral disc (IVD) region to gain knowledge about the normal IVD regeneration pattern.
Disc degeneration is thought to play a major role in patients with chronic lumbar pain. Regeneration processes and cell migration within the IVD have been sparsely described. Therefore, it is of interest to increase knowledge of these processes in order to understand pathological conditions of the IVD.
At the beginning of the experiment, 5-bromo-2-deoxyuridine (BrdU) in vivo labeling was performed in 2 groups of rabbits, 3 and 9 months old (total 27 rabbits). BrdU is incorporated into DNA during mitosis, and then it is gradually diluted with each cell division until it finally disappears. Incorporation of BrdU was then visualized by immunohistochemistry (IHC) at different time points providing cell division pattern and presence of slow-cycling cells in the IVD region. IVD tissue was investigated by IHC for growth and differentiation factor-5 (GDF5), SOX9 (chondrogenic lineage markers), SNAIL homolog 1 (SNAI1), SNAIL homolog 2 (SLUG) (migration markers), and β1-INTEGRIN (cellular adhesion marker). In addition, GDF5, SOX9, and BMPRIB expression were investigated on genetic level.
BrdU cells were observed in early time points in the IVD niche, adjacent to the epiphyseal plate, at later time points mainly in outer region of the annulus fibrosus for both age groups of rabbits, indicating a gradual migration of cells. The presence of SLUG, SNAI1, GDF5, SOX9, and β1-INTEGRIN was found in same regions.
The results suggest a cellular MR from the IVD stem cell niche toward the annulus fibrosus and the inner parts of the IVD. These findings may be of importance for understanding IVD regenerative mechanisms and for future development of biological treatment strategies.
在 2 个年龄组的兔子中进行描述性实验研究。
研究和调查软骨前细胞和细胞迁移途径（MR）在椎间盘（IVD）区域的存在，以了解正常的 IVD 再生模式。
椎间盘退变被认为在患有慢性腰痛的患者中起主要作用。IVD 内的再生过程和细胞迁移描述甚少。因此，增加对这些过程的了解对于理解 IVD 的病理状况很有意义。
在实验开始时，对 3 个月大和 9 个月大的两组兔子（共 27 只兔子）进行体内 5-溴-2-脱氧尿苷（BrdU）标记。BrdU 在有丝分裂期间掺入 DNA，然后随着每个细胞分裂逐渐稀释，直到最终消失。通过免疫组织化学（IHC）在不同时间点观察 BrdU 的掺入，提供 IVD 区域的细胞分裂模式和慢循环细胞的存在。通过免疫组织化学研究 IVD 组织中生长和分化因子-5（GDF5）、SOX9（软骨谱系标记物）、SNAIL 同源物 1（SNAI1）、SNAIL 同源物 2（SLUG）（迁移标记物）和β1-整合素（细胞黏附标记物）。此外，还在遗传水平上研究了 GDF5、SOX9 和 BMPRIB 的表达。
在早期时间点，在 IVD 壁龛中观察到 BrdU 细胞，靠近骺板，在后期时间点，在两个年龄组的兔子的纤维环外区域主要观察到 BrdU 细胞，表明细胞逐渐迁移。在相同区域发现了 SLUG、SNAI1、GDF5、SOX9 和β1-整合素的存在。
结果表明，从 IVD 干细胞壁龛到纤维环以及 IVD 内部存在细胞迁移途径。这些发现对于理解 IVD 再生机制和未来生物治疗策略的发展可能很重要。
