Sheikh Amir M, Barrett Cindy, Villamizar Nestor, Alzate Oscar, Valente Anne Marie, Herlong J Rene', Craig Damian, Lodge Andrew, Lawson Jeffrey, Milano Carmelo, Jaggers James
Department of Pediatric Cardiac Surgery, the Neuroproteomics Center, Durham, NC, USA.
J Thorac Cardiovasc Surg. 2009 May;137(5):1146-53. doi: 10.1016/j.jtcvs.2008.09.013. Epub 2009 Jan 26.
Right ventricular hypertrophy and subsequent dysfunction is common in patients with congenital heart defects, but the molecular mechanisms underlying change from adaptive hypertrophy to dysfunction remain elusive. We used the novel technique of proteomics to characterize protein changes in right ventricular myocardium in a neonatal model of right ventricular hypertrophy and early dysfunction.
Twelve neonatal piglets were equally randomized to pulmonary artery banding (PAB group), or sham operation (thoracotomy without banding). After 4 weeks, right ventricular morphology and function were assessed in vivo using magnetic resonance imaging. Animals were humanely killed. Proteomics of right ventricular myocardium was performed. Purified right ventricular proteins were separated by 2-dimensional difference gel electrophoresis using fluorescent cyanine dyes. After gel imaging, software analysis revealed protein spots differentially expressed between the 2 groups; these spots were excised and identified by mass spectrometry.
On magnetic resonance imaging, animals with pulmonary artery banding demonstrated significant right ventricular hypertrophy, cavity dilatation, and mild systolic impairment (right ventricular ejection fraction 39.8% +/- 15% vs 56.7% +/- 10% controls; P < .05). Right ventricular free wall mass on harvest confirmed right ventricular hypertrophy. Proteomic analysis revealed 18 proteins that were significantly differentially expressed: 5 structural proteins, 6 metabolic enzymes, 2 stress proteins, and 5 miscellaneous proteins. Expression of calsarcin-1 and vinculin was increased, as were certain metabolic enzymes, although F(1)-ATPase beta-chain and heat shock protein 70 decreased.
This is the first study characterizing right ventricular protein changes in a large animal model specifically capturing the change from compensated to maladaptive hypertrophy. These findings can guide future work at elucidating the mechanisms in the pathophysiology of neonatal right ventricular hypertrophy and dysfunction.
右心室肥厚及随后出现的功能障碍在先天性心脏缺陷患者中很常见，但从适应性肥厚转变为功能障碍的分子机制仍不清楚。我们使用蛋白质组学新技术来描述右心室肥厚和早期功能障碍新生儿模型中右心室心肌的蛋白质变化。
将12只新生仔猪平均随机分为肺动脉环扎组（PAB组）或假手术组（开胸但不环扎）。4周后，使用磁共振成像在体内评估右心室形态和功能。对动物实施安乐死。进行右心室心肌的蛋白质组学研究。使用荧光花青染料通过二维差异凝胶电泳分离纯化的右心室蛋白质。凝胶成像后，软件分析显示两组之间差异表达的蛋白质斑点；切除这些斑点并通过质谱鉴定。
在磁共振成像中，肺动脉环扎的动物表现出明显的右心室肥厚、腔扩张和轻度收缩功能损害（右心室射血分数39.8%±15% vs对照组56.7%±10%；P<.05）。收获时右心室游离壁质量证实了右心室肥厚。蛋白质组学分析显示18种蛋白质有显著差异表达：5种结构蛋白、6种代谢酶、2种应激蛋白和5种其他蛋白质。钙肌动蛋白-1和纽蛋白的表达增加，某些代谢酶的表达也增加，尽管F(1)-ATP酶β链和热休克蛋白70减少。
这是第一项在大型动物模型中描述右心室蛋白质变化的研究，该模型专门捕捉从代偿性肥厚到失代偿性肥厚的转变。这些发现可为阐明新生儿右心室肥厚和功能障碍病理生理学机制的未来研究提供指导。
