Grievink Hilbert, Zeltcer Galina, Drenger Benjamin, Berenshtein Eduard, Chevion Mordechai
Department of Biochemistry and Molecular Biology, Hebrew University of Jerusalem, Jerusalem, Israel.
Anesthesiology and Critical Care Medicine, Hebrew University-Hadassah Medical Center, Jerusalem, Israel.
PLoS One. 2016 Jul 22;11(7):e0159951. doi: 10.1371/journal.pone.0159951. eCollection 2016.
Preconditioning (PC) procedures (ischemic or pharmacological) are powerful procedures used for attaining protection against prolonged ischemia and reperfusion (I/R) injury, in a variety of organs, including the heart. The detailed molecular mechanisms underlying the protection by PC are however, complex and only partially understood. Recently, an 'iron-based mechanism' (IBM), that includes de novo ferritin synthesis and accumulation, was proposed to explain the specific steps in cardioprotection generated by IPC. The current study investigated whether nitric oxide (NO), generated by exogenous NO-donors, could play a role in the observed IBM of cardioprotection by IPC. Therefore, three distinct NO-donors were investigated at different concentrations (1-10 μM): sodium nitroprusside (SNP), 3-morpholinosydnonimine (SIN-1) and S-nitroso-N-acetylpenicillamine (SNAP). Isolated rat hearts were retrogradely perfused using the Langendorff configuration and subjected to prolonged ischemia and reperfusion with or without pretreatment by NO-donors. Hemodynamic parameters, infarct sizes and proteins of the methionine-centered redox cycle (MCRC) were analyzed, as well as cytosolic aconitase (CA) activity and ferritin protein levels. All NO-donors had significant effects on proteins involved in the MCRC system. Nonetheless, pretreatment with 10 μM SNAP was found to evoke the strongest effects on Msr activity, thioredoxin and thioredoxin reductase protein levels. These effects were accompanied with a significant reduction in infarct size, increased CA activity, and ferritin accumulation. Conversely, pretreatment with 2 μM SIN-1 increased infarct size and was associated with slightly lower ferritin protein levels. In conclusion, the abovementioned findings indicate that NO, depending on its bio-active redox form, can regulate iron metabolism and plays a role in the IBM of cardioprotection against reperfusion injury.
预处理（PC）程序（缺血性或药理学性）是用于在包括心脏在内的多种器官中实现针对长时间缺血和再灌注（I/R）损伤的保护的有效程序。然而，PC保护作用背后的详细分子机制很复杂，目前仅得到部分理解。最近，有人提出一种“铁基机制”（IBM），其中包括从头合成和积累铁蛋白，以解释缺血预处理（IPC）产生心脏保护作用的具体步骤。本研究调查了外源性一氧化氮（NO）供体产生的NO是否能在IPC所观察到的心脏保护IBM中发挥作用。因此，研究了三种不同的NO供体在不同浓度（1-10μM）下的情况：硝普钠（SNP）、3-吗啉代辛二亚胺（SIN-1）和S-亚硝基-N-乙酰青霉胺（SNAP）。使用Langendorff装置对离体大鼠心脏进行逆行灌注，并在有或无NO供体预处理的情况下进行长时间缺血和再灌注。分析了血流动力学参数、梗死面积以及以蛋氨酸为中心的氧化还原循环（MCRC）的蛋白质，以及胞质乌头酸酶（CA）活性和铁蛋白水平。所有NO供体对MCRC系统中的蛋白质都有显著影响。尽管如此，发现用10μM SNAP预处理对Msr活性、硫氧还蛋白和硫氧还蛋白还原酶蛋白水平产生的影响最强。这些影响伴随着梗死面积显著减小、CA活性增加和铁蛋白积累。相反，用2μM SIN-1预处理会增加梗死面积，并与铁蛋白水平略低有关。总之，上述发现表明，NO根据其生物活性氧化还原形式，可以调节铁代谢，并在针对再灌注损伤的心脏保护IBM中发挥作用。
