Role of phosphorylation of Thr17 residue of phospholamban in mechanical recovery during hypercapnic acidosis
Role of phosphorylation of Thr17 residue of phospholamban in mechanical recovery during hypercapnic acidosis
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DOI：
10.1016/j.cardiores.2004.12.028
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发表时间：
2005-04-01
影响因子：
10.8
通讯作者：
Mattiazzi, A
中科院分区：
文献类型：
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作者：
Mundiña-Weilenmann, C;Ferrero, P;Mattiazzi, A
目的：为了评估磷酸化的受磷蛋白残基的时间过程中，确定这些磷酸化的基本机制，其功能的影响，在acidosis.Methods：Langendorff灌注大鼠心脏的机械恢复提交给30分钟的高碳酸酸中毒。通过特异性抗体的免疫检测，测定受磷蛋白残基的收缩性、舒张性和磷酸化。酸中毒产生机械损伤，随后自发恢复，其中大部分发生在酸中毒的前3分钟内在此期间，收缩性和舒张性分别从其最大抑制恢复了67 +/- 9%和77 +/-11%，以及Thr的Ca 2 +-钙调蛋白依赖性蛋白激酶II（CaMKII）依赖性磷酸化的增加（17）。CaMKII抑制剂KN-93，在1，5和10 μ M，减少Thr（17）磷酸化的基础水平，并产生类似的损害早期松弛恢复（50%）。然而，只有5和10 μ M KN-93抑制早期收缩恢复和完全钝化后期机械恢复。KB-R7943抑制Na+/Ca 2+交换器的反向模式降低Thr（17）磷酸化，但加速早期收缩recovery.Conclusions：CaMK Ⅱ依赖性Thr（17）磷酸化在酸中毒开始时显著增加，负责50%的早期舒张恢复，并与反向Na+/Ca 2+模式的激活有关。早期收缩恢复和晚期机械恢复依赖于CaMKII，但不依赖于受磷蛋白的Thr（17）残基的磷酸化。反向Na+/Ca 2+模式具有反对早期机械恢复的额外的负面影响。(c)2005年欧洲心脏病学会。Elsevier B. V.出版，保留所有权利。
Objectives: To assess the time course of phosphorylation of phospholamban residues, the underlying mechanisms determining these phosphorylations, and their functional impact on the mechanical recovery during acidosis.Methods: Langendorff perfused rat hearts were Submitted to 30 min of hypercapnic acidosis. Contractility, relaxation, and phosphorylation of phospholamban residues, immunodetected by specific antibodies, were determined.Results: Acidosis produced a mechanical impairment followed by a spontaneous recovery, most of which occurred within the first 3 min of acidosis (early recovery), During this period, contractility and relaxation recovered by 67 +/- 9% and 77 +/- 11%, respectively, from its maximal depression, together with an increase in the Ca2+-calmodulin-dependent protein kinase II (CaMKII)-dependent phosphorylation of Thr(17). The CaMKII inhibitor KN-93, at 1, 5 and 10 mu M, decreased Thr(17) phosphorylation to basal levels and produced a similar impairment of the early relaxation recovery (50%). However, only 5 and 10 mu M KN-93 inhibited the early contractile recovery and completely blunted the late mechanical recovery. Inhibition of the reverse mode of the Na+/Ca2+ exchanger by KB-R7943 decreased Thr(17) phosphorylation but accelerated the early contractile recovery.Conclusions: CaMKII-dependent Thr(17) phosphorylation significantly increased at the beginning of acidosis, is responsible for 50% of the early relaxation recovery, and is linked to the activation of the reverse Na+/Ca2+ mode. The early contractile recovery and the late mechanical recovery are dependent on CaMKII but independent of the phosphorylation of the Thr(17) residue of phospholamban. The reverse Na+/Ca2+ mode has an additional negative effect that opposes the early mechanical recovery. (c) 2005 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.