摘要
背景:研究发现前列腺素I2及其类似物可预防压力超负荷性心肌肥厚,以及降低心肌缺血再灌注损伤,然而,其半衰期较短限制了其临床应用。作者前期以来源于骨髓的内皮祖细胞为载体构建了前列腺素I2-内皮祖细胞可持续产生前列腺素I2。目的:观察前列腺素I2-内皮祖细胞对氧化应激引起的心肌细胞损伤的影响。方法:体外培养大鼠心肌细胞H9c2,实验分为4组:(1)H_2O_2干预H9c2细胞4 h。其他3组H9c2在加入H_2O_2前1 h进行条件培养基预处理;(2)分别加入前列腺素I2-内皮祖细胞条件培养基;(3)内皮祖细胞的条件培养基;(4)加入PBS作为空白组。观察条件培养基-前列腺素I2-内皮祖细胞对内皮祖细胞管腔形成能力的影响;应用MTT和Hoechst 33342测定条件培养基对H_2O_2诱导的心肌细胞存活率及凋亡的影响。取雄性SD大鼠分离心肌,应用全细胞膜片钳技术检测条件培养基-前列腺素I2-内皮祖细胞对H_2O_2诱导的大鼠心肌细胞电生理活动的影响。结果与结论:(1)条件培养基-前列腺素I2-内皮祖细胞组管腔形成能力明显强于条件培养基-内皮祖细胞组;(2)与条件培养基-内皮祖细胞组和空白对照组相比,条件培养基-前列腺素I2-内皮祖细胞预处理可显著降低H_2O_2诱导的心肌细胞凋亡和保存细胞存活(P<0.01);(3)条件培养基-前列腺素I2-内皮祖细胞预处理可预防H_2O_2诱导的早期后除极的发生,并且可缩短H_2O_2诱导的动作电位时程的延长(P<0.01);(4)结果提示前列腺素I2-内皮祖细胞通过分泌前列腺素I2保护氧化应激诱导损伤心肌细胞,可以心肌电生理活动作为保护效应的评价指标。
BACKGROUND： Prostacyclin（PGI2） and its analogs have been reported to prevent pressure overload-induced cardiac hypertrophy, and to reduce cardiac ischemia/reperfusion injury. However, clinical application of PGI2 is challenging due to its short half-life（ 2 minutes）. Thus, we have generated PGI2 expressing rat endothelial progenitor cell strains（PGI2-EPCs） that constitutively secrete prostacyclin. OBJECTIVE： To investigate the protective effect of PGI2-EPCs against oxidative stress-induced cardiomyocyte injury. METHODS： Cultured H9c2 cells in vitro were assigned into four groups： H9c2 cells treated by H2O2 for 4 hours. H9c2 cells were pretreated by conditioned medium（collected form EPCs and PGI2-EPCs or collected form EPCs and PGI2-EPCs mixed with native EPCs） before the addition of H2O2. PBS instead of conditioned mediums served as negative control. The paracrine effect of PGI2-EPCs on in vitro angiogenesis of native EPCs was evaluated. MTT and Hoechst 33342 assays were used to examine the protective effect of conditioned medium on H2O2-induced rat embryonic cardiomyocyte apoptosis and cell viability. Finally, the effect of conditioned medium on the electric activities of adult cardiomyocytes was measured by whole-cell patch clamp techniques. RESULTS AND CONCLUSION： When native EPCs mixed with conditioned medium of PGI2-EPCs, the total length of tubes was significantly longer compared with those mixed with CM of EPC. Rat embryonic cardiomyocytes pretreated with conditioned medium of PGI2-EPCs significantly reduced H2O2-induced apoptosis and preserved cell viability compared with pretreatment with EPC-conditioned medium and without pretreatment（P〈0.01）. Pretreatment of rat adult cardiomyocytes with conditioned medium of PGI2-EPCs abolished H2O2-induced early after depolarization and shortened H2O2-induced action potential duration prolongation（P〈0.01） towards baseline. Our findings indicate that PGI2-EPCs protect against oxidative stress-induced cardiomyocyte injury through paracrine action. This Study provides the groundwork for an innovative cell therapy approach to treat ischemic heart disease.
出处
《中国组织工程研究》
CAS
北大核心
2016年第20期2949-2956,共8页
Chinese Journal of Tissue Engineering Research
基金
陕西省科学技术研究发展计划项目(2014KW23-02)
中央高校基本科研业务费专项资金资助~~
