Age-Dependent Changes in AMPK Metabolic Pathways in the Lung in a Mouse Model of Hemorrhagic Shock

作者:Klingbeil Lindsey R; Kim Paul; Piraino Giovanna; O' Connor Michael; Hake Paul W; Wolfe Vivian; Zingarelli Basilia
来源:American Journal of Respiratory Cell and Molecular Biology, 2017, 56(5): 585-596.
DOI:10.1165/rcmb.2016-0118OC

摘要

The development of multiple organ failure in patients with hemorrhagic shock is significantly influenced by patient age. Adenosine monophosphate-activated protein kinase (AMPK) is a crucial regulator of energy homeostasis, which coordinates metabolic repair during cellular stress. We investigated whether AMPK-regulated signaling pathways are age-dependent in hemorrhage-induced lung injury and whether AMPK activation by 5-amino-4imidazole carboxamide riboside (AICAR) affords lung protective effects. Male C57/BL6 young mice (3-5 mo), mature adult mice (9-12 mo), and young AMPK alpha 1 knockout mice (3-5 mo) were subjected to hemorrhagic shock by blood withdrawing, followed by resuscitation with shed blood and lactated Ringer's solution. Plasma proinflammatory cytokines were similarly elevated in C57/BL6 young and mature adult mice after hemorrhagic shock. However, mature adult mice exhibited more severe lung edema and neutrophil infiltration, and higher mitochondrial damage in alveolar epithelial type II cells, than did young mice. No change in autophagy was observed. At molecular analysis, the phosphorylation of the catalytic subunit AMPKa1 was associated with nuclear translocation of peroxisome proliferator-activated receptor gamma co-activator-alpha in young, but not mature, adult mice. Treatment with AICAR ameliorated the disruption of lung architecture in mice of both ages; however, effects in mature adult mice were different than young mice and also involved inhibition of nuclear factor-kappa B. In youngAMPK alpha 1 knockout mice, AICAR failed to improve hypotension and lung neutrophil infiltration. Our data demonstrate that during hemorrhagic shock, AMPK-dependent metabolic repair mechanisms are important for mitigating lung injury. However, these mechanisms are less competent with age.

  • 出版日期2017-5