CAJ | 학술논문

机体老化与癌症、神经退行性疾病等许多复杂疾病相关。目前，研究者已在外周全血中识别了大量的与老化相关的DNA甲基化标记，这些标记可能反映外周血白细胞在机体老化过程中发生的变化，也可能反映外周血中与年龄相关的细胞构成比例的变化。文章利用3组正常个体外周全血 DNA 甲基化谱，采用 Spearman秩相关分析识别了与老化相关的CpG甲基化位点(age-related DNA methylation CpG sites, arCpGs)并评价了其可重复性；利用去卷积算法估计了各外周血样本中髓性和淋巴性细胞的比例并分析了其与年龄的相关性；比较了在外周全血、CD4+T细胞和CD14+单核细胞中识别的arCpGs的一致性。结果显示，在独立外周全血数据中识别的arCpGs具有显著的可重复性(超几何检验，P=1.65×10?11)。外周血髓性和淋巴性细胞的比例分别与年龄显著正、负相关(Spearman秩相关检验，P<0.05，r≤0.22)，它们间DNA甲基化水平差异较大的CpG位点倾向于在外周全血中被识别为 arCpGs。在 CD4+T细胞中识别的 arCpGs与在外周全血中识别的 arCpGs显著交叠(超几何检验，P=6.14×10?12)，且99.1%的交叠位点在 CD4+T细胞及外周全血中的 DNA甲基化水平与年龄的正、负相关性一致。尽管在 CD14+单核细胞中识别的 arCpGs 与在外周全血中识别的 arCpGs 并不显著交叠，但是在交叠的51个arCpGs中，有90.1%的位点在 CD14+单核细胞、外周全血以及CD4+T细胞中的 DNA甲基化水平与年龄的正、负相关性一致，提示它们可能主要反映细胞间共同的改变。在外周全血中识别的 arCpGs 主要反映某些白细胞共同或特异的DNA甲基化改变，但是也有一部分反映外周血细胞比例构成的变化。
궤체노화여암증、신경퇴행성질병등허다복잡질병상관。목전，연구자이재외주전혈중식별료대량적여노화상관적DNA갑기화표기，저사표기가능반영외주혈백세포재궤체노화과정중발생적변화，야가능반영외주혈중여년령상관적세포구성비례적변화。문장이용3조정상개체외주전혈 DNA 갑기화보，채용 Spearman질상관분석식별료여노화상관적CpG갑기화위점(age-related DNA methylation CpG sites, arCpGs)병평개료기가중복성；이용거권적산법고계료각외주혈양본중수성화림파성세포적비례병분석료기여년령적상관성；비교료재외주전혈、CD4+T세포화CD14+단핵세포중식별적arCpGs적일치성。결과현시，재독립외주전혈수거중식별적arCpGs구유현저적가중복성(초궤하검험，P=1.65×10?11)。외주혈수성화림파성세포적비례분별여년령현저정、부상관(Spearman질상관검험，P<0.05，r≤0.22)，타문간DNA갑기화수평차이교대적CpG위점경향우재외주전혈중피식별위 arCpGs。재 CD4+T세포중식별적 arCpGs여재외주전혈중식별적 arCpGs현저교첩(초궤하검험，P=6.14×10?12)，차99.1%적교첩위점재 CD4+T세포급외주전혈중적 DNA갑기화수평여년령적정、부상관성일치。진관재 CD14+단핵세포중식별적 arCpGs 여재외주전혈중식별적 arCpGs 병불현저교첩，단시재교첩적51개arCpGs중，유90.1%적위점재 CD14+단핵세포、외주전혈이급CD4+T세포중적 DNA갑기화수평여년령적정、부상관성일치，제시타문가능주요반영세포간공동적개변。재외주전혈중식별적 arCpGs 주요반영모사백세포공동혹특이적DNA갑기화개변，단시야유일부분반영외주혈세포비례구성적변화。
Aging is associated with many complex diseases such as cancer and neurodegenerative diseases. Re-cently, many age-related DNA methylation biomarkers in peripheral whole blood have been identified. These bio-markers may reflect DNA methylation changes derived from changes in the number of a specific leukocyte cell type during aging. To clarify the source of these age-related DNA methylation changes, we analysed DNA methylation profile of peripheral whole blood from three independent cohorts of healthy subjects and identified age-related DNA methylation CpG sites (arCpGs) using the Spearman’s rank test with high reproducibility (Hypergeometric test, P=1.65×10?11). Using a deconvolution algorithm, we found that the proportion of myeloid lineage cells was increased while that of lymphoid lineage cells was decreased in the peripheral whole blood with age (Spearman’s rank correla-tion test, P<0.05, r≤0.22). The CpG sites, whose methylation levels were significantly different in myeloid cells and lymphoid cells, were preferentially recognized as arCpGs in peripheral whole blood. Moreover, the arCpGs in CD4+T cells significantly overlapped with that in peripheral whole blood (Hypergeometric test, P=6.14×10?12) and 99.1%of the overlapping arCpGs had consistent positive or negative correlations with age. Though the arCpGs in CD14+monocytes did not significantly overlap with that in peripheral whole blood (Hypergeometric test, P=0.232), 90.1%of 51 overlapping arCpGs were correlated with age in CD14+ monocytes, peripheral whole blood, and CD4+T cells consistently. In summary, most of the methylation changes in arCpGs identified in peripheral whole blood come from common or specific DNA methylation changes in leukocyte subtypes, while part of them reflect alterations in the number of specific cell types of leukocytes.