Carbon monoxide exposure activates ULK1 via AMPK phosphorylation in murine embryonic fibroblasts.
Carbon monoxide exposure activates ULK1 via AMPK phosphorylation in murine embryonic fibroblasts.
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一氧化碳暴露通过小鼠胚胎成纤维细胞中的 AMPK 磷酸化激活 ULK1
DOI：
10.1024/0300-9831/a000714
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Stahl W
中科院分区：
文献类型：
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作者：
Stucki D;Westhoff P;Brilhaus D;Weber APM;Brenneisen P;Stahl W
一氧化碳（CO）是血红素加氧酶（HO）降解血红素时内源性产生的，并被认为是一种气体信号分子。HO-1的表达是由Nrf 2-Keap 1信号通路触发的，该信号通路响应于外源性应激信号和膳食成分，如类黄酮和硫代葡萄糖苷或反应性代谢中间体，如4-羟基壬烯醛。内源性CO影响能量代谢，调节葡萄糖的利用并解决CYP 450酶。利用CORM-401研究了内源性CO对细胞ATP合成、AMP信号转导和AMPK通路激活的影响。当细胞暴露于CORM-401时，线粒体ATP产生速率显著降低（P= 0.007）至约50%，而糖酵解ATP合成不变（P= 0.489）。总ATP水平的影响较小，通过质谱法测定。相反，与对照相比，CORM-401暴露后ADP和AMP水平分别升高约2倍（P= 0.022）和4倍（P= 0.012）。AMP浓度增加可激活AMPK，AMPK α亚基Thr 172磷酸化增加10 - 15倍（P= 0.025）。AMPK的下游靶标是触发自噬和线粒体吞噬过程的激酶ULK 1。ULK 1在Ser 555处的磷酸化水平升高3至5倍（P= 0.004）证明了CO暴露后ULK 1的活化。目前的数据表明，内源性CO的产生导致AMP的量增加，AMP介导AMPK依赖性下游效应并可能触发自噬过程。由于膳食成分及其代谢产物诱导CO产生酶HO-1的表达，因此CO信号传导也可能参与细胞对营养因子的反应。
Carbon monoxide (CO) is endogenously produced upon degradation of heme by heme oxygenases (HOs) and is suggested to act as a gaseous signaling molecule. The expression of HO-1 is triggered by the Nrf2-Keap1 signaling pathway which responds to exogenous stress signals and dietary constituents such as flavonoids and glucosinolates or reactive metabolic intermediates like 4-hydroxynonenal. Endogenous CO affects energy metabolism, regulates the utilization of glucose and addresses CYP450 enzymes. Using the CO releasing molecule-401 (CORM-401), we studied the effect of endogenous CO on ATP synthesis, AMP-signaling and activation of the AMPK pathway in cell culture. Upon exposure of cells to CORM-401, the mitochondrial ATP production rate was significantly decreased (P= 0.007) to about 50%, while glycolytic ATP synthesis was unchanged (P= 0.489). Total ATP levels were less affected as determined by mass spectrometry. Instead, levels of ADP and AMP were elevated following CORM-401 exposure by about two-(P= 0.022) and four-fold (P= 0.012) compared to control, respectively. Increased concentrations of AMP activate AMPK which was demonstrated by a 10 to 15-fold increased phosphorylation of Thr172 of the α-subunit of AMPK (P= 0.025). A downstream target of AMPK is the kinase ULK1 which triggers autophagic and mitophagic processes. Activation of ULK1 after CO exposure was proven by a 3 to 5-fold elevated phosphorylation of ULK1 at Ser555 (P= 0.004). The present data suggest that production of endogenous CO leads to increasing amounts of AMP which mediates AMPK-dependent downstream effects and likely triggers autophagic processes. Since dietary constituents and their metabolites induce the expression of the CO producing enzyme HO-1, CO signaling may also be involved in the cellular response to nutritional factors.