Department of Orthopaedics and Rehabilitation Medicine, Faculty of Medical Sciences, The University of Fukui, Fukui, Japan.
Tissue Eng Part A. 2009 Dec;15(12):3835-46. doi: 10.1089/ten.tea.2009.0250.
The nucleus pulposus (NP) of the intervertebral disc in cattle and humans shows the most dramatic changes with aging of any cartilaginous tissue. In humans, notochordal cells disappear from the NP and are replaced with chondrocytic cells by adolescence. However, notochordal cells of the NP persist into adult life in some species, such as rats and rabbits. Therefore, comparison of the metabolic activity of notochordal and nonnotochordal cells is considered to be important for determining the type of cell to use for transplantation to regenerate intervertebral discs. In this study, we investigated the notochordal NP cells of rats and rabbits, as well as nonnotochordal (chondrocyte-like) bovine NP cells, in a three-dimensional culture system to examine whether proteoglycan metabolism varied among these three cell types. As a result, bovine NP cells produced around 0.18 mg/mL of glycosaminoglycan after culture for 5 days, while rat and rabbit NP cells produced about four and two times more glycosaminoglycan than bovine cells, respectively. In conclusion, this study demonstrated marked differences of energy metabolism and production of matrix components between notochordal and nonnotochordal NP cells. Animals with notochordal cells in the NP, such as rats and rabbits, may not provide good models for investigation of biological repair and tissue engineering for human disc disorders.
牛和人类的椎间盘髓核（NP）是所有软骨组织中随年龄变化最显著的组织。在人类中，NP 中的脊索细胞在青春期后消失，并被软骨细胞取代。然而，在一些物种（如大鼠和兔子）中，NP 的脊索细胞会持续存在到成年期。因此，比较脊索细胞和非脊索细胞的代谢活性被认为对于确定用于移植以再生椎间盘的细胞类型很重要。在这项研究中，我们在三维培养系统中研究了大鼠和兔子的脊索 NP 细胞以及非脊索（软骨细胞样）牛 NP 细胞，以检查这三种细胞类型的蛋白聚糖代谢是否存在差异。结果表明，牛 NP 细胞在培养 5 天后产生约 0.18mg/mL 的糖胺聚糖，而大鼠和兔 NP 细胞产生的糖胺聚糖分别比牛细胞多约 4 倍和 2 倍。总之，本研究表明脊索和非脊索 NP 细胞之间在能量代谢和基质成分的产生方面存在显著差异。NP 中有脊索细胞的动物，如大鼠和兔子，可能不是研究人类椎间盘疾病的生物修复和组织工程的良好模型。
