Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy.
PLoS One. 2012;7(4):e35312. doi: 10.1371/journal.pone.0035312. Epub 2012 Apr 13.
Abdominal aortic aneurysm (AAA) is a complex multi-factorial disease with life-threatening complications. AAA is typically asymptomatic and its rupture is associated with high mortality rate. Both environmental and genetic risk factors are involved in AAA pathogenesis. Aim of this study was to investigate telomere length (TL) and oxidative DNA damage in paired blood lymphocytes, aortic endothelial cells (EC), vascular smooth muscle cells (VSMC), and epidermal cells from patients with AAA in comparison with matched controls.
TL was assessed using a modification of quantitative (Q)-FISH in combination with immunofluorescence for CD31 or α-smooth muscle actin to detect EC and VSMC, respectively. Oxidative DNA damage was investigated by immunofluorescence staining for 7, 8-dihydro-8-oxo-2'-deoxyguanosine (8-oxo-dG).
Telomeres were found to be significantly shortened in EC, VSMC, keratinocytes and blood lymphocytes from AAA patients compared to matched controls. 8-oxo-dG immunoreactivity, indicative of oxidative DNA damage, was detected at higher levels in all of the above cell types from AAA patients compared to matched controls. Increased DNA double strand breaks were detected in AAA patients vs controls by nuclear staining for γ-H2AX histone. There was statistically significant inverse correlation between TL and accumulation of oxidative DNA damage in blood lymphocytes from AAA patients. This study shows for the first time that EC and VSMC from AAA have shortened telomeres and oxidative DNA damage. Similar findings were obtained with circulating lymphocytes and keratinocytes, indicating the systemic nature of the disease. Potential translational implications of these findings are discussed.
腹主动脉瘤（AAA）是一种复杂的多因素疾病，具有危及生命的并发症。AAA 通常没有症状，其破裂与高死亡率相关。环境和遗传危险因素都与 AAA 的发病机制有关。本研究旨在比较 AAA 患者和匹配对照的血液淋巴细胞、主动脉内皮细胞（EC）、血管平滑肌细胞（VSMC）和表皮细胞中端粒长度（TL）和氧化 DNA 损伤。
使用定量（Q）-FISH 的改良方法结合 CD31 或α-平滑肌肌动蛋白的免疫荧光检测分别检测 EC 和 VSMC，以评估 TL。通过免疫荧光染色检测 7,8-二氢-8-氧-2'-脱氧鸟苷（8-oxo-dG）来研究氧化 DNA 损伤。
与匹配对照相比，AAA 患者的 EC、VSMC、角质形成细胞和血液淋巴细胞的端粒明显缩短。与匹配对照相比，AAA 患者的所有上述细胞类型中 8-oxo-dG 免疫反应性（指示氧化 DNA 损伤）的水平更高。通过核染色检测 γ-H2AX 组蛋白，在 AAA 患者中检测到 DNA 双链断裂增加。与 AAA 患者的血液淋巴细胞中 TL 与氧化 DNA 损伤的积累之间存在统计学上显著的负相关。本研究首次表明 AAA 的 EC 和 VSMC 具有缩短的端粒和氧化 DNA 损伤。与循环淋巴细胞和角质形成细胞相似的发现表明该疾病具有全身性。讨论了这些发现的潜在转化意义。
