Cardiomyocyte Contractility and Autophagy in a Premature Senescence Model of Cardiac Aging
Cardiomyocyte Contractility and Autophagy in a Premature Senescence Model of Cardiac Aging
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DOI：
10.1155/2020/8141307
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发表时间：
2020-04-15
影响因子：
--
通讯作者：
Ott, Christiane
中科院分区：
文献类型：
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作者：
Haeseli, Steffen;Deubel, Stefanie;Ott, Christiane
在全球范围内，心血管疾病是老龄化人口的主要死亡原因。虽然衰老心脏的临床病理特征已经完全确定，但潜在的分子机制仍然不够清楚。本研究的目的是建立心肌细胞早衰的体外模型体系，将新生C57BL/6J小鼠的心肌细胞培养21天。新生心肌细胞在出生后富氧环境中培养时间延长，可引起心肌细胞的早衰。衰老相关的β-半乳糖苷酶活性、p16、p53和p21等细胞周期调节因子的增加、蛋白质聚集体的积累以及(宏观)自噬的减少限制了蛋白质分解，从而决定了与年龄相关的细胞功能的变化。此外，该培养系统的功能特征是细胞形态和收缩能力的变化。细胞大小的增加与心钠素的诱导表达相关，显示了应激诱导的新生儿心肌细胞肥大的表型。利用最近开发的分析软件工具Mycyter，我们能够显示培养过程中自发收缩行为的时空约束。在本研究中，21天培养的新生心肌细胞被定义为心脏早衰的功能模型系统，以研究与年龄相关的心肌细胞收缩和自噬的变化。
Globally, cardiovascular diseases are the leading cause of death in the aging population. While the clinical pathology of the aging heart is thoroughly characterized, underlying molecular mechanisms are still insufficiently clarified. The aim of the present study was to establish an in vitro model system of cardiomyocyte premature senescence, culturing heart muscle cells derived from neonatal C57Bl/6J mice for 21 days. Premature senescence of neonatal cardiac myocytes was induced by prolonged culture time in an oxygen-rich postnatal environment. Age-related changes in cellular function were determined by senescence-associated beta-galactosidase activity, increasing presence of cell cycle regulators, such as p16, p53, and p21, accumulation of protein aggregates, and restricted proteolysis in terms of decreasing (macro-)autophagy. Furthermore, the culture system was functionally characterized for alterations in cell morphology and contractility. An increase in cellular size associated with induced expression of atrial natriuretic peptides demonstrated a stress-induced hypertrophic phenotype in neonatal cardiomyocytes. Using the recently developed analytical software tool Myocyter, we were able to show a spatiotemporal constraint in spontaneous contraction behavior during cultivation. Within the present study, the 21-day culture of neonatal cardiomyocytes was defined as a functional model system of premature cardiac senescence to study age-related changes in cardiomyocyte contractility and autophagy.