Heat shock-induced manganese superoxide dismutase enhances the tolerance of cardiac myocytes to hypoxia-reoxygenation injury.
Heat shock-induced manganese superoxide dismutase enhances the tolerance of cardiac myocytes to hypoxia-reoxygenation injury.
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热休克诱导的锰超氧化物歧化酶增强心肌细胞对缺氧复氧损伤的耐受性。
DOI：
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发表时间：
1997
影响因子：
5
通讯作者：
M. Hori
中科院分区：
文献类型：
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作者：
N. Yamashita;S. Hoshida;M. Nishida;J. Igarashi;N. Taniguchi;M. Tada;T. Kuzuya;M. Hori
本研究采用新生大鼠心肌细胞缺氧-复氧耐受模型，探讨热休克诱导心肌细胞缺血-再灌注耐受的机制。暴露于热休克（42摄氏度，1小时）的心肌细胞表现出1.8倍的锰超氧化物歧化酶（Mn-SOD）的mRNA水平增加40分钟后v控制细胞。24 h后Mn-SOD含量从0.49 ± 0.04 μ g/mg蛋白增加到0.68 ± 0.05 μ g/mg蛋白（P<0. 05）。05）。热休克蛋白72（hsp 72;诱导型）的mRNA和蛋白质水平也显着增加热休克暴露后。缺氧时心肌细胞肌酸激酶（CK）的释放和ATP的耗竭（pO 2：7 mmHg，3 h）和复氧（pO 2：143 mmHg）在热休克预处理后显著降低（CK：1.18 ± 0.14 U/l v0.62 ± 0.13 U/l，ATP：11.9 ± 1.1 nmol/mg protein v16.2 ± 1.0 nmol/mg protein，P<0.05）。Mn-SOD反义寡脱氧核苷酸（1.5 μ mol/l）可完全抑制热休克诱导的Mn-SOD（0.47+/-0.05 μ g/mg蛋白），但不能抑制热休克诱导的hsp 72，并消除热休克诱导的CK释放（1.04+/-0.15 U/l，P<0.05）和ATP水平（11.04 +/-0.15 U/l，P<0.05）的降低。2+/-1.1nmol/mg蛋白，P<0.05）。结果表明，Mn-SOD的诱导，而不是热休克蛋白72的诱导，在热休克诱导的新生大鼠心肌细胞缺氧-复氧耐受的获得中起着关键作用。
We evaluated the mechanism of the heat shock-induced tolerance to ischemia-reperfusion using a model of hypoxia-reoxygenation tolerance in neonatal rat cardiac myocytes. Myocytes exposed to heat shock (42 degrees C, 1 h) exhibited a 1.8-fold increase in levels of manganese superoxide dismutase (Mn-SOD) mRNA after 40 min v control cells. The concentration of Mn-SOD increased from 0.49+/-0.04 microg/mg protein to 0.68+/-0.05 microg/mg protein after 24 h (P<0. 05). Levels of heat shock protein 72 (hsp72; inducible form) mRNA and protein also increased markedly after heat shock exposure. The release of creatine kinase (CK) from the myocytes and the depletion of ATP level in the myocytes exposed to hypoxia (pO2: 7 mmHg, 3 h) and reoxygenation (pO2: 143 mmHg) were significantly reduced following heat shock pretreatment (CK: 1.18+/-0.14 U/l v 0.62+/-0.13 U/l, ATP: 11.9+/-1.1 nmol/mg protein v 16.2+/-1.0 nmol/mg protein, P<0.05). Treatment with antisense oligodeoxyribonucleotides to Mn-SOD (1.5 micromol/l) completely inhibited the heat shock-associated induction of Mn-SOD (0.47+/-0.05 microg/mg protein), but not hsp72, and abolished the heat shock-induced decrease in CK release (1.04+/-0.15 U/l, P<0.05) and depletion of ATP level (11. 2+/-1.1 nmol/mg protein, P<0.05). Results indicate that Mn-SOD induction, not hsp72 induction, plays a pivotal role in the heat shock-induced acquisition of tolerance to hypoxia-reoxygenation in neonatal rat cardiac myocytes.