Lama Polly, Tiwari Jerina, Mutreja Pulkit, Chauhan Sukirti, Harding Ian J, Dolan Trish, Adams Michael A, Maitre Christine Le
Department of Anatomy, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Sikkim, India.
Centre for Clinical Anatomy, University of Bristol, Bristol, UK.
Anat Cell Biol. 2023 Sep 30;56(3):382-393. doi: 10.5115/acb.23.067. Epub 2023 Jul 28.
Cell clusters are a histological hallmark feature of intervertebral disc degeneration. Clusters arise from cell proliferation, are associated with replicative senescence, and remain metabolically, but their precise role in various stages of disc degeneration remain obscure. The aim of this study was therefore to investigate small, medium, and large size cell-clusters. For this purpose, human disc samples were collected from 55 subjects, aged 37-72 years, 21 patients had disc herniation, 10 had degenerated non-herniated discs, and 9 had degenerative scoliosis with spinal curvature <45°. 15 non-degenerated control discs were from cadavers. Clusters and matrix changes were investigated with histology, immunohistochemistry, and Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Data obtained were analyzed with spearman rank correlation and ANOVA. Results revealed, small and medium-sized clusters were positive for cell proliferation markers Ki-67 and proliferating cell nuclear antigen (PCNA) in control and slightly degenerated human discs, while large cell clusters were typically more abundant in severely degenerated and herniated discs. Large clusters associated with matrix fissures, proteoglycan loss, matrix metalloproteinase-1 (MMP-1), and Caspase-3. Spatial association findings were reconfirmed with SDS-PAGE that showed presence to these target markers based on its molecular weight. Controls, slightly degenerated discs showed smaller clusters, less proteoglycan loss, MMP-1, and Caspase-3. In conclusion, cell clusters in the early stages of degeneration could be indicative of repair, however sustained loading increases large cell clusters especially around microscopic fissures that accelerates inflammatory catabolism and alters cellular metabolism, thus attempted repair process initiated by cell clusters fails and is aborted at least in part via apoptosis.
细胞簇是椎间盘退变的组织学标志性特征。细胞簇由细胞增殖产生，与复制性衰老相关，且保持代谢活性，但其在椎间盘退变各个阶段的确切作用仍不清楚。因此，本研究的目的是调查小、中、大尺寸的细胞簇。为此，从55名年龄在37 - 72岁的受试者中收集了人类椎间盘样本，其中21例患者患有椎间盘突出症，10例患有退变但未突出的椎间盘，9例患有脊柱侧弯角度<45°的退行性脊柱侧弯。15个未退变的对照椎间盘来自尸体。采用组织学、免疫组织化学和十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS - PAGE）研究细胞簇和基质变化。对获得的数据进行Spearman等级相关性分析和方差分析。结果显示，在对照和轻度退变的人类椎间盘中，小尺寸和中等尺寸的细胞簇对细胞增殖标志物Ki - 67和增殖细胞核抗原（PCNA）呈阳性，而大细胞簇通常在严重退变和突出的椎间盘中更为丰富。大细胞簇与基质裂隙、蛋白聚糖丢失、基质金属蛋白酶 - 1（MMP - 1）和半胱天冬酶 - 3相关。SDS - PAGE再次证实了空间关联结果，该结果根据分子量显示了这些靶标标志物的存在。对照、轻度退变的椎间盘显示出较小的细胞簇、较少的蛋白聚糖丢失、MMP - 1和半胱天冬酶 - 3。总之，退变早期的细胞簇可能表明有修复作用，然而持续的负荷会增加大细胞簇，尤其是在微观裂隙周围，这会加速炎症分解代谢并改变细胞代谢，因此由细胞簇启动的修复过程失败，至少部分是通过细胞凋亡而终止。
