Gastroenterological Surgery, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan.
World J Gastroenterol. 2013 May 28;19(20):3027-42. doi: 10.3748/wjg.v19.i20.3027.
To investigate the role of matrix metalloproteinase (MMP)-9 in the pathogenesis of postoperative liver failure (PLF) after extended hepatectomy (EH).
An insufficient volume of the remnant liver (RL) results in higher morbidity and mortality, and a murine model with 80%-hepatectomy was used. All investigations were performed 6 h after EH. Mice were first divided into two groups based on the postoperative course (i.e., the PLF caused or did not), and MMP-9 expression was measured by Western blotting. The source of MMP-9 was then determined by immunohistological stainings. Tissue inhibitor of metalloproteinase (TIMP)-1 is the endogenous inhibitor of MMP-9, and MMP-9 behavior was assessed by the experiments in wild-type, MMP-9(-/-) and TIMP-1(-/-) mice by Western blotting and gelatin zymography. The behavior of neutrophils was also assessed by immunohistological stainings. An anti-MMP-9 monoclonal antibody and a broad-spectrum MMP inhibitor were used to examine the role of MMP-9.
Symptomatic mice showed more severe PLF (histopathological assessments: 2.97 ± 0.92 vs 0.11 ± 0.08, P < 0.05) and a higher expression of MMP-9 (71085 ± 18274 vs 192856 ± 22263, P < 0.01). Nonnative leukocytes appeared to be the main source of MMP-9, because MMP-9 expression corresponding with CD11b positive-cell was observed in the findings of immunohistological stainings. In the histopathological findings, the PLF was improved in MMP-9(-/-) mice (1.65% ± 0.23% vs 0.65% ± 0.19%, P < 0.01) and it was worse in TIMP-1(-/-) mice (1.65% ± 0.23% vs 1.78% ± 0.31%, P < 0.01). Moreover, neutrophil migration was disturbed in MMP-9(-/-) mice in the immunohistological stainings. Two methods of MMP-9 inhibition revealed reduced PLF, and neutrophil migration was strongly disturbed in MMP-9-blocked mice in the histopathological assessments (9.6 ± 1.9 vs 4.2 ± 1.2, P < 0.05, and 9.9 ± 1.5 vs 5.7 ± 1.1, P < 0.05).
MMP-9 is important for the process of PLF. The initial injury is associated with MMP-9 derived from neutrophils, and MMP-9 blockade reduces PLF. MMP-9 may be a potential target to prevent PLF after EH and to overcome an insufficient RL.
研究基质金属蛋白酶（MMP）-9 在扩大肝切除（EH）后肝衰竭（PLF）发病机制中的作用。
剩余肝脏（RL）体积不足会导致更高的发病率和死亡率，因此使用 80%肝切除术的小鼠模型。所有研究均在 EH 后 6 小时进行。首先根据术后病程（即发生或未发生 PLF）将小鼠分为两组，并通过 Western blot 测定 MMP-9 的表达。然后通过免疫组织化学染色确定 MMP-9 的来源。组织金属蛋白酶抑制剂（TIMP）-1 是 MMP-9 的内源性抑制剂，通过在野生型、MMP-9（-/-）和 TIMP-1（-/-）小鼠中进行 Western blot 和明胶酶谱实验评估 MMP-9 行为。还通过免疫组织化学染色评估中性粒细胞的行为。使用抗 MMP-9 单克隆抗体和广谱 MMP 抑制剂来研究 MMP-9 的作用。
有症状的小鼠表现出更严重的 PLF（组织病理学评估：2.97±0.92 与 0.11±0.08，P<0.05）和更高的 MMP-9 表达（71085±18274 与 192856±22263，P<0.01）。非天然白细胞似乎是 MMP-9 的主要来源，因为在免疫组织化学染色的结果中观察到与 CD11b 阳性细胞相对应的 MMP-9 表达。在组织病理学发现中，MMP-9（-/-）小鼠的 PLF 得到改善（1.65%±0.23%与 0.65%±0.19%，P<0.01），而 TIMP-1（-/-）小鼠的 PLF 更差（1.65%±0.23%与 1.78%±0.31%，P<0.01）。此外，MMP-9（-/-）小鼠中的中性粒细胞迁移在免疫组织化学染色中受到干扰。两种 MMP-9 抑制方法均显示 PLF 减少，并且 MMP-9 阻断的小鼠中性粒细胞迁移在组织病理学评估中受到强烈干扰（9.6±1.9 与 4.2±1.2，P<0.05，和 9.9±1.5 与 5.7±1.1，P<0.05）。
MMP-9 对 PLF 过程很重要。初始损伤与来自中性粒细胞的 MMP-9 有关，MMP-9 阻断可减少 PLF。MMP-9 可能是预防 EH 后 PLF 和克服 RL 不足的潜在靶点。
