Huang Pei, Hawthorne Wayne J, Ao Peng, Angeli Giavanna L, Medbury Heather J, Fletcher John P
Department of Surgery, University of Sydney, Westmead Hospital, Westmead, Australia.
J Vasc Surg. 2002 Aug;36(2):371-8. doi: 10.1067/mva.2002.123749.
The mechanisms of neointima formation after synthetic vascular grafting are not clear. The aim of this study was to investigate the intima and perigraft adventitia remodeling process in terms of cell apoptosis versus proliferation after synthetic patch implantation.
Female Merino sheep were randomized equally into two groups and underwent implantion with a patch of gelatin sealed Dacron graft into the left common carotid artery. At 1 and 6 months, grafted vessels were harvested, processed, and assessed. Intimal area and lumen sizes were measured with histologic assessment of eight segments from each animal assisted with image analysis. Immunohistochemical labeling of alpha-actin and D33 desmin was performed on tissue sections of perigraft adventitia, graft matrix, and intima. Cell proliferation and cell phenotype were determined with double immunohistochemical staining with anti-proliferating cell nuclear antigen and anti-alpha-actin or antimacrophage antibodies (HAM 56) in perigraft adventitia, graft matrix, and intima. Apoptosis was detected with in situ terminal deoxynucleiotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate-fluorescence nick end labeling (TUNEL) in perigraft adventitia, graft matrix, and intima.
The carotid artery lumen size at 6 months was significantly larger than at 1 month (P <or=.05). The intimal area was significantly reduced at 6 months compared with 1 month (P <.05). At 1 month and 6 months, perigraft adventitia, graft matrix, and intima showed positive alpha-actin expression but negative desmin staining. In the anastomotic area, a small number of intimal cells suggested their muscle origin (expression alpha-actin and desmin). The number of proliferating cells in the intima was significantly greater at 1 month than at 6 months (P =.01). TUNEL-positive cells were significantly greater in the intima at 1 month than at 6 months (P <.05), whereas TUNEL-positive cells were significantly greater at 6 months in the perigraft adventitia (P <.05). HAM 56-positive cells in the intima at 1 month were significantly greater compared with 6 months (P <.05), whereas in graft and perigraft regions, no significant difference was seen between 1 month and 6 months.
The cell proliferation and cell phenotype change in intima and perigraft adventitia are associated with thickening of perigraft adventitia and intima at 1 month. The balance between cell proliferation and apoptosis could account in part for the reduction in intima area and perigraft adventitial cellularity at 6 months.
合成血管移植后新生内膜形成的机制尚不清楚。本研究旨在探讨合成补片植入后内膜及移植血管周围外膜在细胞凋亡与增殖方面的重塑过程。
将雌性美利奴绵羊平均随机分为两组，在左颈总动脉植入明胶密封的涤纶补片。于1个月和6个月时，获取移植血管，进行处理和评估。通过组织学评估每只动物的8个节段，并借助图像分析测量内膜面积和管腔大小。对移植血管周围外膜、移植基质和内膜的组织切片进行α-肌动蛋白和结蛋白D33的免疫组织化学标记。通过抗增殖细胞核抗原与抗α-肌动蛋白或抗巨噬细胞抗体（HAM 56）的双重免疫组织化学染色，确定移植血管周围外膜、移植基质和内膜中的细胞增殖及细胞表型。采用原位末端脱氧核苷酸转移酶介导的2'-脱氧尿苷5'-三磷酸荧光缺口末端标记法（TUNEL）检测移植血管周围外膜、移植基质和内膜中的细胞凋亡情况。
6个月时颈动脉管腔大小显著大于1个月时（P≤0.05）。与1个月时相比，6个月时内膜面积显著减小（P<0.05）。在1个月和6个月时，移植血管周围外膜、移植基质和内膜α-肌动蛋白表达呈阳性，但结蛋白染色呈阴性。在吻合区域，少数内膜细胞显示出肌源性特征（α-肌动蛋白和结蛋白表达）。内膜中增殖细胞数量在1个月时显著多于6个月时（P = 0.01）。TUNEL阳性细胞在1个月时内膜中显著多于6个月时（P<0.05），而TUNEL阳性细胞在6个月时移植血管周围外膜中显著多于1个月时（P<0.05）。内膜中HAM 56阳性细胞在1个月时显著多于6个月时（P<0.05），而在移植血管及周围区域，1个月和6个月之间未见显著差异。
内膜及移植血管周围外膜中的细胞增殖和细胞表型变化与1个月时移植血管周围外膜和内膜增厚有关。细胞增殖与凋亡之间的平衡可能部分解释了6个月时内膜面积和移植血管周围外膜细胞数量的减少。
