REDUCED BETA(1) RECEPTOR MESSENGER-RNA ABUNDANCE IN THE FAILING HUMAN HEART
REDUCED BETA(1) RECEPTOR MESSENGER-RNA ABUNDANCE IN THE FAILING HUMAN HEART
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DOI：
10.1172/jci116891
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发表时间：
1993-12-01
影响因子：
15.9
通讯作者：
FELDMAN, AM
中科院分区：
文献类型：
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作者：
BRISTOW, MR;MINOBE, WA;FELDMAN, AM
人类心力衰竭的特点是心肌肾上腺素能信号转导的改变，其中最突出的是β -肾上腺素能受体的下调。我们验证了在衰竭的人类心脏中β 1-肾上腺素能受体的下调与β 1受体mRNA稳态水平下降有关的假设。由于beta1受体mRNA的丰度极低，只能通过定量聚合酶链反应（QPCR）或RNase保护方法进行测量。由于beta1受体基因无内含子，且beta1受体mRNA丰度较低，QPCR产生了总RNA的基因组扩增，而mRNA的测量必须在poly(A)+富集的RNA中进行。通过QPCR检测到β 1受体mRNA的浓度为0.34 ~ 7.8 × 10(7)分子/杯poly(A)+富集RNA，对16.7 zeptomol敏感。使用从器官供体（未衰竭心室，n = 12）或心脏移植受者（衰竭心室，n = 13）获得的100 mg等分左心室心肌，QPCR测量的beta1 mRNA水平分别为4.2+/-0.7 x 10(7)/杯和2.10+/-0.3 x 10(7)/杯（p = 0.006）。在相同的非衰竭和衰竭左心室中，β -肾上腺素能受体密度分别为67.9+/-6.9 fmol/mg和29.6+/-3.5 fmol/mg （P = 0.0001）。总RNA的RNase保护实验证实了衰竭心室中mRNA丰度的降低，也表明β 1信息丰度降低了50%。我们得出结论，在衰竭的人类心脏中，β 1受体mRNA的下调有助于β 1肾上腺素能受体的下调。
Heart failure in humans is characterized by alterations in myocardial adrenergic signal transduction, the most prominent of which is down-regulation of beta1-adrenergic receptors. We tested the hypothesis that down-regulation of beta1-adrenergic receptors in the failing human heart is related to decreased steady-state levels of beta1 receptor mRNA. Due to the extremely low abundance of beta1 receptor mRNA, measurements were possible only by quantitative polymerase chain reaction (QPCR) or by RNase protection methods. Because the beta1 receptor gene is intronless and beta1 receptor mRNA abundance is low, QPCR yielded genomic amplification in total RNA, and mRNA measurements had to be performed in poly(A)+-enriched RNA. By QPCR the concentration of beta1 receptor mRNA varied from 0.34 to 7.8 x 10(7) molecules/mug poly(A)+-enriched RNA, and the assay was sensitive to 16.7 zeptomol. Using 100-mg aliquots of left ventricular myocardium obtained from organ donors (nonfailing ventricles, n = 12) or heart transplant recipients (failing ventricles, n = 13), the respective beta1 mRNA levels measured by QPCR were 4.2+/-0.7 x 10(7)/mug vs. 2.10+/-0.3 X 10(7)/mug (p = 0.006). In these same nonfailing and failing left ventricles the respective beta1-adrenergic receptor densities were 67.9+/-6.9 fmol/mg vs. 29.6+/-3.5 fmol/mg (P = 0.0001 ). Decreased mRNA abundance in the failing ventricles was confirmed by RNase protection assays in total RNA, which also demonstrated a 50% reduction in beta1 message abundance. We conclude that down-regulation of beta1 receptor mRNA contributes to down-regulation of beta1 adrenergic receptors in the failing human heart.