CAJ | 학술논문

目的观察研究增龄和负重对椎间盘软骨终板(cartilage endplate,CEP)形态与细胞凋亡的影响.方法通过手术截肢及特殊饲养建立双后肢大鼠模型(n=45),取同龄正常大鼠作为对照组(n=40).在3、6、9、12月龄时实验组和对照组分别随机选取8只处死观察,取出L4-5椎间盘及相邻上下椎体组织.椎间盘取材后,行苏木精-伊红染色以及TUNEL染色.计数软骨终板区活细胞以及凋亡细胞数目,并且测量软骨终板厚度,计算软骨终板缺损程度.结果凋亡首先显著出现于软骨终板中,随着年龄的增加凋亡逐渐加剧,并直接导致细胞密度的显著降低.实验组软骨终板内软骨细胞的凋亡率在6月龄时较对照组明显增加,实验组6、9月龄组间比较差异有统计学意义(P<0.05).相关分析显示,软骨终板活细胞数目与椎间盘软骨终板破损程度具有相关性,相关系数为-0.97(P<0.05),呈高度相关.实验组的软骨终板结构较对照组发生更严重的退变,软骨终板钙化层明显增厚、非钙化层变薄并出现裂隙.结论除增龄因素外,负重是增加细胞凋亡、加重椎间盘软骨终板破损和退变的重要因素.
목적 관찰연구증령화부중대추간반연골종판(cartilage endplate,CEP)형태여세포조망적영향.방법 통과수술절지급특수사양건립쌍후지대서모형(n=45),취동령정상대서작위대조조(n=40).재3、6、9、12월령시실험조화대조조분별수궤선취8지처사관찰,취출L4-5추간반급상린상하추체조직.추간반취재후,행소목정-이홍염색이급TUNEL염색.계수연골종판구활세포이급조망세포수목,병차측량연골종판후도,계산연골종판결손정도.결과 조망수선현저출현우연골종판중,수착년령적증가조망축점가극,병직접도치세포밀도적현저강저.실험조연골종판내연골세포적조망솔재6월령시교대조조명현증가,실험조6、9월령조간비교차이유통계학의의(P<0.05).상관분석현시,연골종판활세포수목여추간반연골종판파손정도구유상관성,상관계수위-0.97(P<0.05),정고도상관.실험조적연골종판결구교대조조발생경엄중적퇴변,연골종판개화층명현증후、비개화층변박병출현렬극.결론 제증령인소외,부중시증가세포조망、가중추간반연골종판파손화퇴변적중요인소.
Objective To investigate the impact of aging and weight bearing on cartilage endplate morphology and chondrocyte apoptosis in rats. Methods The bipedal rat model (n=45) was developed by forelimb amputation and special breeding methods. The normal rats of the same age served as the control group (n=40). When the rats became 3, 6, 9, and 12 months old, 8 rats randomly selected from each group were sacrificed and paraffin-embedded mid-sagittal sections of the L4-5 spine were obtained. Sections were stained with hematoxylin and eosin and the TUNEL procedure was performed. The numbers of apoptotic cells and viable cells in the cartilage endplates of the intervertebral discs were counted, the thickness of the cartilage endplate was measured and the degree of impairment of the cartilage endplate was evaluated. Results Apoptosis first appeared in the cartilage endplate, then increased with aging and resulted in a remarkable decrease in cell density. The apoptotic rate of chondrocytes within the cartilage endplate of the bipedal rat model group was significantly higher than the control group at the 6-month time point. A statistically significant difference was observed in the bipedal rat model group between the 6-month time point and 9-month time point (P<0.05). Correlation analyses indicated that there was a highly negative correlation between the number of the viable cells of the cartilage endplate and the degree of the cartilage endplate degeneration (r=-0.97, P<0.05). Compared with the naturally aged group, the bipedal rat model group experienced more severe degeneration in the structure of the cartilage endplate, more obvious thickening of the cartilage endplate's calcified layer, and more defects in the structure of the cartilage. Conclusions Besides aging, weight bearing is probably a key factor of the increase of chondrocyte apoptosis and the degeneration of vertebral cartilage endplate.