Department of Surgery K, Bispebjerg Hospital, Bispebjerg Bakke 23, DK 2400 Copenhagen NV, Denmark.
Int J Colorectal Dis. 2013 Aug;28(8):1151-9. doi: 10.1007/s00384-013-1697-6. Epub 2013 Apr 26.
Submucosal collagen is paramount for colonic anastomotic integrity. Matrix metalloproteinases (MMPs) mediate collagen degradation that increases the risk of wound dehiscence. Although broad-spectrum MMP inhibitors are beneficial for anastomotic strength, they can cause adverse reactions. Knowledge of specific MMPs responsible for the weakening of anastomoses can be used to optimise MMP inhibition therapy. We aimed to quantify transcript and protein levels of multiple MMPs in colonic anastomoses and evaluate the effect of inhibiting the MMPs that displayed the highest expression levels on anastomotic repair.
Left-sided colonic anastomoses were made in male Sprague-Dawley rats. After 3 days when biomechanical strength is lowest, MMP mRNA and protein levels were measured by quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assays and gelatin zymography. The effects of the MMP-8, MMP-9 and MMP-12 synthetic inhibitor AZD3342 was also studied.
MMP-8, MMP-9 and MMP-12 gene and protein expression increased profoundly (p < 0.01), and MMP-13 mRNA and MMP-2 mRNA and protein modestly (p < 0.001) in the anastomoses. MMP-3 mRNA levels were not up-regulated significantly compared with adjacent uninjured colon. Increased anastomotic MMP-12 levels paralleled macrophage infiltration by immunohistochemical analyses. AZD3342 (50 mg/kg) treatment increased the anastomotic breaking strength by 29% (p = 0.015) day 3 compared with vehicle. Improved anastomotic strength was not accompanied with alterations of type I or type III procollagen mRNA but was possibly due to inhibition of the concerted digestive action on the existent submucosal collagens by the targeted MMPs.
The present findings justify the concept of selective MMP inhibition to enhance anastomotic strength in colon.
黏膜下胶原对于结肠吻合完整性至关重要。基质金属蛋白酶（MMPs）介导胶原降解，增加了伤口裂开的风险。尽管广谱 MMP 抑制剂有益于吻合强度，但它们可能引起不良反应。了解负责吻合减弱的特定 MMP 可以用于优化 MMP 抑制治疗。我们旨在定量检测结肠吻合处多种 MMP 的转录物和蛋白水平，并评估抑制表达水平最高的 MMP 对吻合修复的影响。
雄性 Sprague-Dawley 大鼠进行左侧结肠吻合术。在生物力学强度最低的第 3 天，通过定量实时聚合酶链反应、酶联免疫吸附试验和明胶酶谱法测量 MMP mRNA 和蛋白水平。还研究了 MMP-8、MMP-9 和 MMP-12 合成抑制剂 AZD3342 的作用。
MMP-8、MMP-9 和 MMP-12 的基因和蛋白表达显著增加（p<0.01），MMP-13mRNA 和 MMP-2mRNA 和蛋白适度增加（p<0.001）。与未受伤的相邻结肠相比，MMP-3mRNA 水平没有显著上调。免疫组织化学分析表明，吻合处 MMP-12 水平的增加与巨噬细胞浸润平行。与载体相比，AZD3342（50mg/kg）治疗在第 3 天使吻合破裂强度增加了 29%（p=0.015）。吻合强度的改善并没有伴随着 I 型或 III 型前胶原 mRNA 的改变，但可能是由于靶向 MMP 对现存黏膜下胶原的协同消化作用被抑制。
本研究结果支持选择性 MMP 抑制以增强结肠吻合强度的概念。
