首頁 > 期刊首頁 > 中華皮膚科雜志 > 2008年10期 > 不同年齡段人群皮膚組織中兩種mtDNA缺失研究
不同年齡段人群皮膚組織中兩種mtDNA缺失研究
Detection of large deletions in mitochondrial DNA during skin aging
- doi：
- 摘要：
- 目的 定量觀察不同年齡段健康人群皮膚組織中線粒體DNA(mtDNA)大片段4977 bp和3895 bp缺失的發生情況,探討與自然老化及日光照射之間的關聯性. 方法 收集不同年齡段71例皮膚組織,曝光部位(頸項部、手背部或額面部)31例,非曝光部位(臀部、大腿部或腰腹部)40例,分別提取其基因組DNA,以普通PCR對mtDNA中的4977 bp缺失和3895 bp缺失突變進行擴增,并以熒光實時定量PCR法對mtDNA中的4977 bp缺失和3895 bp缺失突變進行定量榆測和分析. 結果 普通PCR檢測顯示4977 bp缺失和3895 bp缺失的發生率均隨年齡增大而增加,40歲以后人群中mtDNA的4977 bp缺失和3895 bp缺失發生率分別高達47.5%(19/40)和30.0%(12/40),顯著高于40歲以前人群(X2分別為4.673,6.118.P<0.05).4977 bp缺失和3895 bp缺失在曝光部位的總發生率為48.4%(15/31)和32.3%(9/31),較非曝光部位升高,但兩者相比差異并無統計學意義.定量PCR檢測結果表明4977 bp缺失和3895 bp缺失的相對拷貝數無論在曝光還是非曝光部位,均與年齡增長呈正相關(rg分別為0.907,0.845,P<0.05);但4977 bp缺失在曝光與非曝光部位的突變數相比差異無統計學意義(P=0.264),而3895 bp缺失在曝光與非曝光部位相比差異卻有統計學意義(P=0.014). 結論 mtDNA中4977 bp缺失主要與自然老化相關,可作為觀察皮膚自然老化進程的指標之一.3895 bp的缺失與紫外線照射具有更為密切的聯系.
- Abstract：
- Objective To quantitatively observe the actual levels of 4977 bp and 3895 bp mitochon-drial DNA (mtDNA) deletion in healthy human skin of different age, and to explore their relationship with intrinsic aging and photoaging. Methods Seventy-one samples of skin tissue were obtained from healthy volunteers, including 40 samples from UV-protected areas (buttock, thigh, waist or abdomen) and 31 from UV-exposed areas (neck, back of hands, forehead or face). Nuclear and mitochundrial DNA was extracted from these samples. Conventional PCR was performed to detect the incidence of 4977 bp and 3895 bp mtDNA deletion. Then, SYBR Green real-time PCR was applied to quantitatively analyze the target mutations in posi-tive samples. Results Conventional PCR showed that the incidence of both 4977 bp deletion and 3895 bp deletion increased with age. For example, the incidence of 4977 bp deletion and 3895 bp deletion accounted for 47.5% (19/40) and 30% (12/40), respectively in samples from volunteers older than 40 years, signifi-cantly higher than that in those from volunteers younger than 40 years (X2 = 4.673, 6.118, respectively, both P < 0.05). The total incidence of 4977 bp deletion and 3895 bp deletion in UV-exposed areas was 48.4% (15/31) and 32.3% (9/31), respectively, which did not differ from those in UV-protected areas. The results from real-time PCR revealed a positive correlation of the copy number of 4977 10p deletion and 3895 bp deletion with age (rg = 0.907, 0.845, respectively, both P < 0.05). When the UV-exposed area was compared with the UV-protected area, no significant difference was found in the copy number of 4977 bp deletion ( P = 0.264), whereas a higher level of 3895 bp deletion was noticed in UV-exposed area (P = 0.014). Conclu-sions The 4977 bp mtDNA deletion is primarily associated with chronological aging, and might serve as a biomarker for the process of chronological aging of skin. Deletion of 3895 bp mtDNA seems to be more sus-ceptible to ultraviolet radiation.
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