大骨节病与骨性关节炎DNA甲基化衰老时钟的比较研究

A comparative study of premature senescence of chondrocytes in patients with Kashin-Beck disease and osteoarthritis using DNA methylation aging clock

目的探讨大骨节病和骨性关节炎的软骨细胞是否存在过早衰老。方法收集大骨节病、骨性关节炎和对照组的膝关节软骨样本各5例,样本均来源于西安交通大学第二附属医院。提取膝关节软骨样本DNA,采用Illumina Infinium HumanMethylation450 BeadChip芯片技术对其进行DNA甲基化分析。同时,基于全基因组甲基化数据,利用线上DNA甲基化衰老时钟计算器(https://dnamage.genetics.ucla.edu/home)计算样本的DNA甲基化年龄,并与实际年龄进行比较。结果在大骨节病组与对照组的比较中,发现1212个差异甲基化CpG位点,包括497个高甲基化CpG位点和715个低甲基化CpG位点,分别对应264个高甲基化基因和368个低甲基化基因;在骨性关节炎组与对照组的比较中,发现656个差异甲基化CpG位点,包括343个高甲基化CpG位点和313个低甲基化CpG位点,分别对应177个高甲基化基因和174个低甲基化基因。在上述比较中,检测到367个重叠CpG位点(对应182个基因),这些位点在大骨节病组与对照组以及骨性关节炎组与对照组的比较中均存在差异甲基化表达。DNA甲基化衰老时钟结果表明,大骨节病、骨性关节炎以及对照组DNA甲基化年龄与实际年龄的平均年龄加速度差异分别为2.549、0.017、-5.364岁,大骨节病组和骨性关节炎组DNA甲基化年龄均大于实际年龄。结论大骨节病和骨性关节炎的软骨细胞均存在过早衰老。

Objective To explore if there is premature senescence of chondrocytes in patients with Kashin-Beck disease(KBD)and osteoarthritis.Methods Five knee cartilage samples of KBD,osteoarthritis and control groups were collected,respectively,from the Second Affiliated Hospital of Xi'an Jiaotong University.DNA was then extracted from cartilage samples and DNA methylation was analyzed by Illumina Infinium HumanMethylation450 BeadChip.At the same time,based on genome-wide methylation data,the online DNA methylation aging clock calculator(https://dnamage.genetics.ucla.edu/home)was used to calculate the DNA methylation age(DNAm age)of samples,and the results were compared with their actual ages.Results In the comparison between KBD group and control group,1212 differentially methylated CpG sites were found,including 497 hypermethylated CpG sites and 715 hypomethylated CpG sites,corresponding to 264 hypermethylated genes and 368 hypomethylated genes,respectively.In the comparison between osteoarthritis group and control group,656 differentially methylated CpG sites were found,including 343 hypermethylated CpG sites and 313 hypomethylated CpG sites,corresponding to 177 hypermethylated genes and 174 hypomethylated genes,respectively.In the above comparison,367 overlapped CpG sites(corresponding to 182 genes)were found,which were differentially methylated in both KBD and control groups and osteoarthritis and control groups.The results of DNA methylation aging clock showed that the average age acceleration differences between DNAm age and actual age of KBD,osteoarthritis and control groups were 2.549,0.017,and-5.364 years,respectively,the DNAm ages of KBD and osteoarthritis groups were greater than the actual ages.Conclusion The chondrocytes show premature senescence in both KBD and osteoarthritis.