Martin J L, Mestril R, Hilal-Dandan R, Brunton L L, Dillmann W H
Department of Medicine, University of California, San Diego, La Jolla 92093-0618, USA.
Circulation. 1997 Dec 16;96(12):4343-8. doi: 10.1161/01.cir.96.12.4343.
Overexpression of the inducible hsp70 protects against ischemic cardiac damage. However, it is unclear whether the small heat shock proteins hsp27 and alphaB-crystallin protect against ischemic injury.
Our aim was to examine whether the overexpression of hsp27 and alphaB-crystallin in neonatal and adult rat cardiomyocytes would protect against ischemic injury. Recombinant adenovirus expressing hsp27 or alphaB-crystallin under the control of the cytomegalovirus promoter was used to infect cardiac myocytes at high efficiency as assessed by immunostaining. Overexpression was confirmed by Western blot analysis. Cardiomyocytes were subjected to simulated ischemic stress, and survival was estimated through assessment of lactate dehydrogenase and creatine phosphokinase release. The hsp27 overexpression decreased lactate dehydrogenase release by 45+/-7.5% in adult cardiomyocytes but had no effect in the neonatal cells. In contrast, alphaB-crystallin overexpression was associated with a decrease in cytosolic enzyme release in both adult (29+/-6.6%) and neonatal (32+/-5.4%) cardiomyocytes. Decreased endogenous hsp25 with an antisense adenovirus produced a 29+/-9.9% increase in damage with simulated ischemia. Overexpression of the inducible hsp70 in adult cardiomyocytes was associated with a 34+/-4.6% decrease in lactate dehydrogenase release and is in line with our previous results in neonatal cardiomyocytes.
The increased expression of hsp27 and alphaB-crystallin through an adenovirus vector system protects against ischemic injury in adult cardiomyocytes. Likewise, the overexpression of alphaB-crystallin protects against ischemic damage in neonatal cardiomyocytes. Decreasing the high levels of endogenous hsp25 present in neonatal cardiomyocytes renders them more susceptible to damage caused by simulated ischemia.
诱导型热休克蛋白70（hsp70）的过表达可保护心脏免受缺血性损伤。然而，小分子热休克蛋白hsp27和αB-晶状体蛋白是否能保护心脏免受缺血性损伤尚不清楚。
我们的目的是研究在新生和成年大鼠心肌细胞中hsp27和αB-晶状体蛋白的过表达是否能保护心脏免受缺血性损伤。通过免疫染色评估，利用在巨细胞病毒启动子控制下表达hsp27或αB-晶状体蛋白的重组腺病毒高效感染心肌细胞。通过蛋白质免疫印迹分析证实了过表达。对心肌细胞施加模拟缺血应激，并通过评估乳酸脱氢酶和肌酸磷酸激酶的释放来估计细胞存活率。hsp27过表达使成年心肌细胞中乳酸脱氢酶的释放减少了45±7.5%，但对新生心肌细胞没有影响。相比之下，αB-晶状体蛋白的过表达与成年（29±6.6%）和新生（32±5.4%）心肌细胞中细胞溶质酶释放的减少有关。用反义腺病毒降低内源性hsp25水平会使模拟缺血损伤增加29±9.9%。成年心肌细胞中诱导型hsp70的过表达与乳酸脱氢酶释放减少34±4.6%有关，这与我们之前在新生心肌细胞中的结果一致。
通过腺病毒载体系统增加hsp27和αB-晶状体蛋白的表达可保护成年心肌细胞免受缺血性损伤。同样，αB-晶状体蛋白的过表达可保护新生心肌细胞免受缺血性损伤。降低新生心肌细胞中高水平的内源性hsp25会使其更容易受到模拟缺血引起的损伤。
