小分子药物kartogenin保护终板软骨退变的实验研究

Experimental study on small molecule drug kartogenin protecting endplate cartilage degeneration

目的:研究小分子药物kartogenin(KGN)对终板软骨组织细胞外基质分泌的影响,探讨其在终板软骨以及椎间盘退变中的作用。方法:建立大鼠椎间盘体外器官退变模型,分为对照组、退变组(穿刺注射生理盐水)、KGN处理组(穿刺注射100nmol/L KGN),利用HE染色观察终板软骨及椎间盘形态,番红-固绿染色观察终板软骨细胞外基质的分泌。通过Real time-PCR评价三组终板软骨组织中Ⅱ型胶原、蛋白多糖、SOX-9的表达变化,Western blot检测Ⅱ型胶原、SOX-9蛋白表达变化。结果:HE染色结果显示与对照组比较,退变组椎间盘髓核消失,终板软骨减少,发生明显退变,KGN处理组椎间盘结构较完整;番红-固绿染色可见实验组较对照组终板软骨细胞外基质分泌增多。Realtime-PCR结果显示退变组终板软骨组织Ⅱ型胶原、蛋白聚糖及SOX-9表达明显下调,KGN处理组中终板软骨组织Ⅱ型胶原、蛋白聚糖及SOX-9表达上调;Western blot结果显示实验组软骨细胞中Ⅱ型胶原、SOX-9蛋白表达明显增高。结论:体外穿刺及培养能够诱导椎间盘及终板软骨的退变,小分子药物KGN能够促进终板软骨细胞外基质的分泌从而保护终板软骨及椎间盘的退变。

AIM： To observe the effect of small molecule drug kartogenin （KGN） on pro- moting extracellular matrix secretion in endplate cartilage, and explore its protective role in the endplate cartilage or intervertebral disc degener- ation. METHODS： Established an in vitro organ culture model of rat intervertebral disc, punc- tured the annulus and cultured in vitro. The rats were divided into three groups： control group, degeneration group and KGN treated group. The change of histomorphology in intervertebral disc tissue was assessed by HE staining, the ex- tracellular matrix of endplate cartilage was ob- served by safranin O-fast green staining. The expressions of type Ⅱ collagen, proteoglycans and SOX-9 in the three groups were detected by Real time-PCR. The expressions of type Ⅱ Colla- gen and SOX-9 protein were measured by west- ern blot. RESULTS： HE staining indicated that the nucleus disappeared and the endplate carti-lage tended to thin in the degeneration group, and the disc structure is more complete after KGN treated; safranin O- fast green staining showed that the secretion of extracellular matrix were increased in the KGN treated group. Real- time-PCR showed type Ⅱ collagen, aggrecan, and SOX-9 mRNA levels were significantly re- duced in the degeneration group, and the carti- lage-related gene increased after KGN treated; Western blot results showed similar changes. CONCLUSION： Small molecule drug KGN can promote the extracellular matrix secretion in the endplate cartilage in order to protect the end- plate cartilage and intervertebral disc degenera- tion.