背景:目前已有针对lncRNA\miRNA\mRNA的共表达网络对骨关节炎发生发展调控机制的研究,课题组前期研究已通过数据库筛选出符合条件的NONHSAT248596.1和miR-146a-5p,尚缺乏体内实验来验证上述调控机制. 目的:探究NONHSAT248596.1在基质细胞衍生因子1/4型趋化因子受体轴介导体内骨关节炎软骨退变进程中对miR-146a-5p发挥的竞争性内源性RNA调控作用. 方法:取36只新西兰兔,通过向右侧后肢膝关节注射基质细胞衍生因子1溶液建立骨关节炎模型,采用随机数字表法分4组,lncRNA组、miRNA组、ceRNA组、对照组分别向造模膝关节内注射NONHSAT248596.1过表达的慢病毒载体、miR-146a-5p过表达的慢病毒载体、miR-146a-5p+ NONHSAT248596.1过表达的慢病毒载体及空慢病毒载体.造模第 4,8,12 周,取膝关节软骨组织和软骨下骨组织进行相关检测. 结果与结论:①苏木精-伊红与番红O固绿染色显示,4组软骨组织都有不同程度的退变表现,造模第4周时,lncRNA组软骨组织中的软骨细胞肿胀、细胞极性消失,细胞外基质破坏,出现表层糜烂、裂缝形成和软骨组织局部或全层缺失,并随时间延长软骨损伤程度逐渐加重,4组中miRNA组关节软骨炎症进展最缓慢;②qRT-PCR检测显示,相同时间点下,lncRNA组软骨组织中NONHSAT248596.1、4型趋化因子受体、基质金属蛋白酶3,9及13的mRNA表达量高于其他3组(P<0.05),miR-146a-5p、聚集蛋白聚糖及Ⅱ型胶原的mRNA表达量低于其他3组(P<0.05);造模后第8,12周,miRNA组软骨组织中的NONHSAT248596.1、4型趋化因子受体、基质金属蛋白酶3,9及13的mRNA表达量低于ceRNA组、对照组(P<0.05),miR-146a-5p、聚集蛋白聚糖及Ⅱ型胶原的mRNA表达量高于ceRNA组、对照组(P<0.05);③Western Blot检测显示,相同时间点下,lncRNA组软骨组织中的聚集蛋白聚糖及Ⅱ型胶原蛋白表达量始终低于其他3组(P<0.05);miRNA组造模后第8,12周软骨组织中的聚集蛋白聚糖及Ⅱ型胶原蛋白表达量高于ceRNA组、对照组(P<0.05);④结果表明,miR-146a-5p作为NONHSAT248596.1的作用靶点会受到其竞争性内源性RNA的作用造成活性被抑制,NONHSAT248596.1作用于miR-146a-5p后调控基质细胞衍生因子1/4型趋化因子受体轴,影响骨关节炎软骨组织中基质金属蛋白、Ⅱ型胶原、聚集蛋白聚糖的表达,造成细胞外基质的降解及蛋白多糖的丢失.
BACKGROUND:Currently,there have been studies on the regulatory mechanism of lncRNA\miRNA\mRNA co-expression network on the occurrence and development of osteoarthritis.Our research group has screened qualified NONHSAT248596.1 and miR-146a-5p through the database in the previous stage,but the corresponding in vivo experiments to verify the above regulatory mechanisms are still lacking. OBJECTIVE:To explore the role of NONHSAT248596.1 in regulating competitive endogenous RNA of miR-146a-5p in cartilage degeneration mediated by stromal cell derived factor type 1/chemokine receptor 4 axis in vivo. METHODS:The models of osteoarthritis were established in 36 New Zealand rabbits by injecting stromal cell derived factor 1 solution into the knee joint of the right hind limb.According to the random number table method,they were divided into four groups.lncRNA group,miRNA group,ceRNA group and control group were injected with lentivirus vector overexpressing NONHSAT248596.1,lentivirus vector overexpressing miR-146a-5p,lentivirus vector overexpressing miR-146a-5p+NONHSAT248596.1 and empty lentivirus vector into the molded knee joint,respectively.At 4,8 and 12 weeks of modeling,cartilage tissues and subchondral bone tissues of the knee joint were taken for relevant detection. RESULTS AND CONCLUSION:Hematoxylin-eosin staining and safranin fast green staining showed different degrees of degeneration in the four groups.At 4 weeks,the cartilage tissue of the lncRNA group showed swelling of chondrocytes,loss of cell polarity,destruction of extracellular matrix,surface erosion,fracture formation and partial or full layer loss of cartilage tissue.The degree of cartilage injury was gradually aggravated with time.The progression of articular cartilage inflammation in the miRNA group was the slowest among the four groups.qRT-PCR showed that at the same time point,mRNA expression levels of NONHSAT248596.1,chemokine receptor 4,matrix metalloproteinase 3,matrix metalloproteinase 9 and matrix metalloproteinase 13 in cartilage tissue of the lncRNA group were higher than those of the other three groups(P<0.05).The mRNA expression levels of miR-146a-5p,aggrecan and type Ⅱ collagen were lower than those of the other three groups(P<0.05).The mRNA expression levels of NONHSAT248596.1,chemokine receptor 4,matrix metalloproteinase 3,matrix metalloproteinase 9 and matrix metalloproteinase 13 in the miRNA group were lower than those in the ceRNA group and control group at 8 and 12 weeks after the model construction(P<0.05).The mRNA expressions of miR-146a-5p,aggrecan and type Ⅱ collagen were higher than those of the ceRNA group and control group(P<0.05).Western blot assay showed that at the same time point,the expression levels of aggrecan and type Ⅱ collagen in cartilage tissue of the lncRNA group were always lower than those of the other three groups(P<0.05).The expression levels of aggrecan and type Ⅱ collagen in cartilage tissue of the miRNA group at 8 and 12 weeks after modeling were higher than those of the ceRNA group and control group(P<0.05).The results showed that miR-146a-5p,as the target of NONHSAT248596.1,could be inhibited by the effect of its ceRNA.After acting on miR-146a-5p,NONHSAT248596.1 regulates the stromal cell derived factor type 1/chemokine receptor 4 axis to affect the expression of matrix metalloprotein,type Ⅱ collagen,and aggrecan in osteoarthritis chondrocytes,resulting in the degradation of extracellular matrix and the loss of proteoglycan.