Department of Orthopedic Surgery, Brigham and Women's Hospital and Harvard Medical School.
Spine (Phila Pa 1976). 2023 May 15;48(10):728-736. doi: 10.1097/BRS.0000000000004530. Epub 2023 Mar 1.
Isolated human nucleus pulposus (hNP) cells from the degenerated intervertebral disc (IVD) were incubated under hydrostatic pressure (HP) and evaluated for regenerative potential.
To characterize metabolic turnover in hNP cells isolated from degenerated IVDs classified by Pfirrmann grade under physiologically relevant HP at high osmolality in vitro.
We demonstrated that bovine caudal nucleus pulposus cells isolated from healthy cows produced more extracellular matrix under cyclic HP followed by constant pressure (mimicking physiological intradiscal pressure in humans) than under no pressure in vitro. We assessed the effects of pressure on human degenerated cells isolated under the same regimen of pressure used for bovine cells.
hNP cells isolated from discarded tissue classified as Pfirrmann grade 2 to 3 (n = 13: age, 46.7 ± 14.0) and grade 4 (n = 13: age, 53.0 ± 11.5) were incubated under cyclic HP at 0.2 to 0.7 MPa, 0.5 Hz for 2 days followed by constant pressure at 0.3 MPa for 1 day, repeated twice over 6 days. The gene expression and immunohistology of matrix molecules and catabolic and anticatabolic proteins were evaluated.
Aggrecan and collagen type II expression were significantly more upregulated under HP in grades 2 to 3 than in grade 4 tissues (both, P < 0.01). Linear regression analysis showed a positive correlation between matrix metalloproteinase 13 and tissue inhibitor for metalloproteinase 2 expression in grades 2 to 3, whereas a negative correlation was found in grade 4 ( P < 0.05). Immunohistological staining revealed the activation of a mechanoreceptor, transient receptor potential vanilloid 4, under HP.
Resident cells in mild-moderate degenerated discs classified as Pfirrmann grade 2 to 3 have the potential to promote extracellular matrix production and maintain adequate cell viability under physiological spinal loading.
This study explored the potential of degenerated remnant nucleus pulposus cells under a physiological environment, possibly leading to establishing strategies for IVD regeneration.
从退变的椎间盘（IVD）中分离出的人髓核（hNP）细胞在静水压力（HP）下孵育，并评估其再生潜能。
在高渗透压下，体外模拟生理椎间盘内压，对 Pfirrmann 分级退变的 hNP 细胞进行代谢转换特征分析。
我们已经证明，从健康牛的尾骨中分离出来的牛尾核细胞在周期性 HP 后，比在无压力下，能产生更多的细胞外基质，随后是恒压（模拟人类生理椎间盘内压）。我们评估了在与牛细胞相同的压力方案下分离出的人退变细胞的压力影响。
从 Pfirrmann 分级 2 至 3 级（n = 13：年龄，46.7 ± 14.0）和 4 级（n = 13：年龄，53.0 ± 11.5）的废弃组织中分离 hNP 细胞，在 0.2 至 0.7 MPa、0.5 Hz 的循环 HP 下孵育 2 天，然后在 0.3 MPa 的恒压下孵育 1 天，6 天重复 2 次。评估了基质分子和分解代谢及抗分解代谢蛋白的基因表达和免疫组织化学。
在 2 至 3 级，与 4 级组织相比，HP 下聚集蛋白聚糖和 II 型胶原的表达明显上调（均 P < 0.01）。线性回归分析显示，在 2 至 3 级，基质金属蛋白酶 13 和金属蛋白酶抑制剂 2 的表达呈正相关，而在 4 级呈负相关（P < 0.05）。免疫组织化学染色显示，在 HP 下，机械感受器瞬时受体电位香草醛 4 被激活。
在 Pfirrmann 分级为 2 至 3 级的轻度至中度退变椎间盘内的固有细胞，在生理脊柱负荷下具有促进细胞外基质产生和维持足够细胞活力的潜力。
本研究探索了生理环境下退变剩余髓核细胞的潜能，可能为建立椎间盘再生策略奠定基础。
