Cpxm2 as a novel candidate for cardiac hypertrophy and failure in hypertension [Affymetrix]. Cpxm2 as a novel candidate for cardiac hypertrophy and failure in hypertension [Affymetrix]

We assigned carboxypeptidase X 2 (Cpxm2) to a genetic locus for left ventricular mass. The functional role of Cpxm2 was investigated in Cpxm2-deficient (KO) and wild-type (WT) mice exposed to deoxycorticosterone acetate (DOCA)-salt hypertension and control conditions (SHAM). Both WT and KO animals developed severe and similar systolic hypertension in response to DOCA. WT mice developed severe LV damage. These changes were significantly ameliorated or even normalized (i.e. ejection fraction) in KO-DOCA animals. LV transcriptome analysis in WT, but not in KO mice, showed a molecular cardiac hypertrophy/remodeling signature with significant upregulation of 1234 transcripts including Cpxm2 in response to DOCA. Overall design: In the mouse model whole transcriptome profiling was performed on LV tissues from male SHAM and DOCA animals of both WT and KO mice (n = 3, respectively). The RNA was processed and hybridized on the GeneChip® Mouse Gene 2.0 ST Array (Affymetrix UK Ltd., High Wycombe, UK). Total RNA for both microarray workflows was prepared for hybridization according to the manufacturer’s instructions.

我们将羧肽酶X 2（Cpxm2）定位至调控左心室质量的遗传位点。本研究在暴露于醋酸脱氧皮质酮（DOCA）盐性高血压模型及对照假手术（SHAM）条件下的Cpxm2敲除（KO）与野生型（WT）小鼠中，探究了Cpxm2的功能作用。WT与KO小鼠均会在DOCA处理后出现严重且程度相近的收缩期高血压。WT小鼠会出现严重的左心室损伤，而KO-DOCA组小鼠的上述损伤则得到显著改善，甚至可恢复至正常水平（如射血分数）。对WT小鼠（而非KO小鼠）的左心室转录组分析显示，DOCA刺激可诱导其出现以1234个转录本（包括Cpxm2）显著上调为特征的心肌肥厚/重构分子特征。
整体实验设计：本小鼠模型实验中，我们对WT与KO小鼠的雄性假手术组及DOCA处理组的左心室组织开展全转录组表达谱分析，每组各3只小鼠。总RNA按照标准流程处理后，在GeneChip®小鼠基因2.0 ST芯片（英国Affymetrix有限公司，海威科姆，英国）上进行杂交。本研究中两种微阵列实验流程所需的总RNA，均按照制造商的操作指南制备以用于杂交。