Institute of Pathology, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany.
Department of Internal Medicine II, University Medical Center Regensburg, 93053 Regensburg, Germany.
Int J Mol Sci. 2024 Jul 12;25(14):7644. doi: 10.3390/ijms25147644.
Mitochondria play a crucial role in adapting to fluctuating energy demands, particularly in various heart diseases. This study investigates mitochondrial morphology near intercalated discs in left ventricular (LV) heart tissues, comparing samples from patients with sinus rhythm (SR), atrial fibrillation (AF), dilated cardiomyopathy (DCM), and ischemic cardiomyopathy (ICM).
Transmission electron microscopy was used to analyze mitochondria within 0-3.5 μm and 3.5-7 μm of intercalated discs in 9 SR, 10 AF, 9 DCM, and 8 ICM patient samples. Parameters included mean size in µm and elongation, count, percental mitochondrial area in the measuring frame, and a conglomeration score.
AF patients exhibited higher counts of small mitochondria in the LV myocardium, resembling SR. DCM and ICM groups had fewer, larger, and often hydropic mitochondria. Accumulation rates and percental mitochondrial area were similar across groups. Significant positive correlations existed between other defects/size and hydropic mitochondria and between count/area and conglomeration score, while negative correlations between count and size/other defects and between hydropic mitochondria and count could be seen as well.
Mitochondrial parameters in the LV myocardium of AF patients were similar to those of SR patients, while DCM and ICM displayed distinct changes, including a decrease in number, an increase in size, and compromised mitochondrial morphology. Further research is needed to fully elucidate the pathophysiological role of mitochondrial morphology in different heart diseases, providing deeper insights into potential therapeutic targets and interventions.
线粒体在适应波动的能量需求方面起着至关重要的作用，特别是在各种心脏疾病中。本研究比较了窦性心律（SR）、心房颤动（AF）、扩张型心肌病（DCM）和缺血性心肌病（ICM）患者的左心室（LV）心脏组织中闰盘附近的线粒体形态。
采用透射电子显微镜分析了 9 例 SR、10 例 AF、9 例 DCM 和 8 例 ICM 患者样本中闰盘 0-3.5μm 和 3.5-7μm 处的线粒体。参数包括µm 的平均大小和伸长率、计数、测量框内的线粒体百分比面积以及凝聚评分。
AF 患者的 LV 心肌中小线粒体的计数较高，类似于 SR。DCM 和 ICM 组的线粒体数量较少，体积较大，且常呈水肿状态。各组的积累率和线粒体百分比面积相似。其他缺陷/大小与水肿性线粒体之间存在显著的正相关，计数/面积与凝聚评分之间也存在正相关，而计数与大小/其他缺陷之间以及水肿性线粒体与计数之间存在负相关。
AF 患者 LV 心肌中的线粒体参数与 SR 患者相似，而 DCM 和 ICM 则显示出明显的变化，包括数量减少、体积增大和线粒体形态受损。需要进一步研究来充分阐明线粒体形态在不同心脏疾病中的病理生理作用，为潜在的治疗靶点和干预措施提供更深入的认识。
