1Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium. 2Division of Intensive Care, Cliniques Universitaires Saint Luc, Brussels, Belgium. 3Center for Interdisciplinary Research in Biology, INSERM U1050, CNRS UMR7241, Collège de France, Paris, France. 4Division of Cardiology, Cliniques Universitaires Saint Luc, Brussels, Belgium. 5Laboratory of Thrombosis and Hemostasis, GIGA-Cardiovascular Sciences, University of Liège, Liège, Belgium. 6Institute of Interdisciplinary Research in Human and Molecular Biology, Université Libre de Bruxelles, Brussels, Belgium. 7INSERM U1016, Institut Cochin, Paris, France. 8CNRS, UMR8104, Paris, France. 9Université Paris Descartes, Sorbonne Paris Cité, France.
Crit Care Med. 2013 Dec;41(12):e411-22. doi: 10.1097/CCM.0b013e31829866dc.
As adenosine monophosphate (AMP)-activated protein kinase both controls cytoskeleton organization in endothelial cells and exerts anti-inflammatory effects, we here postulated that it could influence vascular permeability and inflammation, thereby counteracting cardiac wall edema during sepsis.
Controlled animal study.
University research laboratory.
C57BL/6J, α1AMPK, and α1AMPK mice.
Sepsis was triggered in vivo using a sublethal injection of lipopolysaccharide (O55B5, 10 mg/kg), inducing systolic left ventricular dysfunction. Left ventricular function, edema, vascular permeability, and inflammation were assessed in vivo in both wild-type mice (α1AMPK) and α1AMP-activated protein kinase-deficient mice (α1AMPK). The 5-aminoimidazole-4-carboxamide riboside served to study the impact of AMP-activated protein kinase activation on vascular permeability in vivo. The integrity of endothelial cell monolayers was also examined in vitro after lipopolysaccharide challenge in the presence of aminoimidazole-4-carboxamide riboside and/or after α1AMP-activated protein kinase silencing.
α1AMP-activated protein kinase deficiency dramatically impaired tolerance to lipopolysaccharide challenge. Indeed, α1AMPK exhibited heightened cardiac vascular permeability after lipopolysaccharide challenge compared with α1AMPK. Consequently, an increase in left ventricular mass corresponding to exaggerated wall edema occurred in α1AMPK, without any further decrease in systolic function. Mechanistically, the lipopolysaccharide-induced α1AMPK cardiac phenotype could not be attributed to major changes in the systemic inflammatory response but was due to an increased disruption of interendothelial tight junctions. Accordingly, AMP-activated protein kinase activation by aminoimidazole-4-carboxamide riboside counteracted lipopolysaccharide-induced hyperpermeability in wild-type mice in vivo as well as in endothelial cells in vitro. This effect was associated with a potent protection of zonula occludens-1 linear border pattern in endothelial cells.
Our results demonstrate for the first time the involvement of a signaling pathway in the control of left ventricular wall edema during sepsis. AMP-activated protein kinase exerts a protective action through the preservation of interendothelial tight junctions. Interestingly, exaggerated left ventricular wall edema was not coupled with aggravated systolic dysfunction. However, it could contribute to diastolic dysfunction in patients with sepsis.
由于单磷酸腺苷（AMP）激活的蛋白激酶既能控制内皮细胞的细胞骨架组织，又能发挥抗炎作用，因此我们推测它可能会影响血管通透性和炎症，从而在脓毒症期间对抗心脏壁水肿。
对照动物研究。
大学研究实验室。
C57BL/6J、α1AMPK 和 α1AMPK 小鼠。
体内使用亚致死剂量的脂多糖（O55B5，10mg/kg）注射引发脓毒症，导致收缩期左心室功能障碍。在野生型小鼠（α1AMPK）和 α1AMP 激活蛋白激酶缺陷型小鼠（α1AMPK）中，体内评估左心室功能、水肿、血管通透性和炎症。5-氨基咪唑-4-甲酰胺核苷用于研究 AMP 激活蛋白激酶激活对体内血管通透性的影响。在存在 5-氨基咪唑-4-甲酰胺核苷和/或 α1AMP 激活蛋白激酶沉默的情况下，体外还检查了脂多糖挑战后内皮细胞单层的完整性。
α1AMP 激活蛋白激酶缺乏显著损害了对脂多糖挑战的耐受性。事实上，与 α1AMPK 相比，α1AMPK 在脂多糖挑战后表现出更高的心脏血管通透性。因此，在 α1AMPK 中发生了左心室质量的增加，对应于壁水肿的夸大，而没有进一步降低收缩功能。从机制上讲，脂多糖诱导的 α1AMPK 心脏表型不能归因于全身炎症反应的重大变化，而是由于内皮细胞间紧密连接的破坏增加。因此，5-氨基咪唑-4-甲酰胺核苷对 AMP 激活蛋白激酶的激活在体内抵抗了野生型小鼠的脂多糖诱导的高通透性以及体外的内皮细胞。这种作用与内皮细胞中环扎蛋白-1 线性边界模式的强烈保护有关。
我们的研究结果首次证明了一种信号通路在控制脓毒症期间左心室壁水肿中的参与。AMP 激活蛋白激酶通过保护内皮细胞间紧密连接发挥保护作用。有趣的是，夸大的左心室壁水肿并没有伴随着加重的收缩功能障碍。然而，它可能导致脓毒症患者的舒张功能障碍。
