Protein kinase A catalytic subunit alters cardiac mitochondrial redox state and membrane potential via the formation of reactive oxygen species
Protein kinase A catalytic subunit alters cardiac mitochondrial redox state and membrane potential via the formation of reactive oxygen species
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DOI：
10.1253/circj.71.429
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发表时间：
2007-03-01
影响因子：
3.3
通讯作者：
Hayashi, Hideharu
中科院分区：
文献类型：
--
作者：
Nagasaka, Shiro;Katoh, Hideki;Hayashi, Hideharu
线粒体上蛋白激酶A （PKA）锚定蛋白的鉴定表明PKA对线粒体功能有直接影响。然而，PKA与线粒体代谢之间的关系尚不清楚。方法与结果研究了PKA对皂素渗透大鼠心肌细胞线粒体氧化还原状态（黄素腺嘌呤二核苷酸（FAD））、线粒体膜电位（δ psi m）和活性氧（ROS）产生的影响。PKA催化亚基(PKA(cat)；50单位/ml)使FAD强度提高56.6 +/- 7.9% (p < 0.01), 2'7'-二氯荧光素（DCF）强度提高10.5 +/- 3.3倍（p < 0.01），去极化δ psi(m)达到对照组的48.1 +/- 9.5% （p < 0.01）。Trolox（一种ROS清除剂，100 μ mol/L）抑制PKA（cat）诱导的δ psi(m)、FAD和DCF的改变。PKA（cat）诱导的Delta psi(m)去极化被细胞膜阴离子通道抑制剂（IMAC） 4,4'-二异硫氰酸二苯乙烯-2,2'-二磺酸（DIDS: 1 μ mol/L）抑制，而线粒体通透性过渡孔抑制剂（mPTP）环孢素A（100 nmol/L）不具有抑制作用。结论PKAcat通过线粒体ROS生成改变FAD和AT， PKA（cat）诱导的δ psi(m)去极化不是由mPTP引起的，而是由dids敏感机制引起的，可能是由IMAC打开引起的。PKA对线粒体功能的影响可能与β -肾上腺素能刺激大鼠心肌功能有关。
Background The identification of protein kinase A (PKA) anchoring proteins on mitochondria implies a direct effect of PKA on mitochondrial function. However, little is known about the relationship between PKA and mitochondrial metabolism.Methods and Results The effects of PKA on the mitochondrial redox state (flavin adenine dinucleotide (FAD)), mitochondrial membrane potential (Delta psi m) and reactive oxygen species (ROS) production were investigated in saponin-permeabilized rat cardiomyocytes. The PKA catalytic subunit (PKA(cat); 50 unit/ml) increased FAD intensities by 56.6 +/- 7.9% (p < 0.01), 2'7'-dichlorofluorescin diacetate (DCF) intensities by 10.5 +/- 3.3 fold (p < 0.01) and depolarized Delta psi(m) to 48.1 +/- 9.5% of the control (p < 0.01). Trolox (a ROS scavenger; 100 mu mol/L) inhibited PKA(cat)-induced Delta psi(m), FAD and DCF alteration. PKA(cat)-induced Delta psi(m) depolarization was inhibited by an inhibitor of the inner membrane anion channel (IMAC), 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS: 1 mu mol/L) but not by an inhibitor of mitochondrial permeability transition pore (mPTP), cyclosporine A (100 nmol/L).Conclusions PKAcat alters FAD and AT via mitochodrial ROS generation, and PKA(cat)-induced Delta psi(m), depolarization was not caused by mPTP but rather by DIDS-sensitive mechanisms, which could be caused by opening of the IMAC. The effects of PKA on mitochondrial function could be related to myocardial function under the condition of extensive beta-adrenergic stimulation.