Relationship between age-related changes in functions of endocardial endothelial cells and heart failure

我们分离和培养了年轻(5周龄)和老年(100周龄)大鼠的心内膜内皮细胞(EECs)，以评估与年龄相关的细胞功能变化。通过与猪血管内皮细胞(VECs)的比较，评价EECs的生理功能。结果：用胶原酶分离EECs，在涂有大鼠I型胶原的塑料平板上传代培养。大鼠EECs融合细胞单层呈典型的鹅卵石样形态。通过摄取DiI-Ac-LDL和存在第VIII因子相关抗原检测EECs的纯度，与血管内皮细胞一样，始终为95%。2.衰老对大鼠EECs功能的影响。(1)随着年龄的增长，细胞的增殖和迁移呈下降趋势。(2)随着年龄的增长，细胞内前列环素(PGI_2)和一氧化氮(NO)的生成量显著减少。在跨壁压力作用下，幼年大鼠血管内皮细胞产生的PGI_2显著增强，而老年大鼠血管内皮细胞则无此反应。3：与血管内皮细胞比较：(1)血管内皮细胞的细胞生长和抗聚集能力均高于血管内皮细胞。(2)PGI_2生成量的大小顺序为：左心室ECS和GT、右室EECS和GT、肺动脉ECS和GT、冠状动脉和胸主动脉内皮细胞。(3)跨壁压力增加EEC产生PGI2，降低NO产生。结论EEC功能随增龄而减弱，提示这种功能障碍参与了心力衰竭随增龄而增加的过程。EECS的生理作用在本研究中并未阐明，因为我们不能仅从大鼠的空洞心脏中剥离体外培养的心内膜。如果我们能够建立去除心内膜的方法，其作用将被显著阐明。

We isolated and cultured endocardial endothelial cells (EECs) from young (5-week-old) and aged (100-week-old) rats, to estimate age-related changes in the cell functions. We also estimated physiological functions of EECs, by comparison of EECs with the vascular endothelial cells (VECs), which were isolated from pigs.Results1 : EECs were isolated with collargenase and subcultured on plastic plates coated with the rat type I collagen. The confluent cell monolayr of rat EECs exhibited a typical cobblestone-like morphology. The purity of EECs assayd by uptake of DiI-Ac-LDL and the presence of factor VIII-related antigen, was consistently>95%, as for vascular endothelial cells.2 : Effects of aging on functions of rat EECs. (1) Proliferation and migration tended to decrease with aging. (2) Production of prostaxycline (PGI_2) and nitric oxide (NO) in the cells significantly decreased with aging. When exposing to transmural pressure, PGI_2 production of young rat EECs significantly potentiated, but that of aged rat EECs did not response.3 : Comparison with VECs : (1) Cell growth of EECs and the anti-aggregation property were higher than those of VECs. (2) The rank order of PGI_2 production is left ventricle EECs>right ventricle EECs>pulmonary arterial ECs>coronary arterial and thoracic aortic ECs. (3) The transmural pressure increased PGI_2 production and decreased NO production of EECs.ConclusionThe present experiments indicate age-related attenuation of EEC functions and suggest the participation of the dysfunction in increase of heart failure with advancing age. The physiological roles of EECs were not clarified in this study, since we could not denude ex vivo only the endocardium from rat hole heart. If we can establish the method to remove the endocardium, the roles will be remarkably elucidated.