成年鼠骨髓间充质干细胞体外诱导分化为心肌样细胞

目的探讨成年大鼠骨髓间充质干细胞(MSC)体外培养条件及定向分化为心肌样细胞的可行性。方法通过取成年SD大鼠股骨干骨髓,进行体外培养和传代,用10μmol/L 5-氮杂胞苷(5-aza)分别对原代、一代和三代MSC进行体外定向诱导,用免疫组化方法分析检测分化后细胞的心肌特异性抗原(肌丝蛋白、肌钙蛋白)并通过RT-PCR鉴定心肌细胞特异因子基因(ANP、GATA-4)的表达。结果原代、一代MSC在体外经5-aza诱导4周后,细胞形态无明显变化,而经5-aza诱导4周后的三代MSC形态变大,呈杆形、球形,诱导细胞相互连接,连接细胞出现肌管样结构。免疫组化检测经10μmol/L 5-aza诱导4周的原代、一代MSC未见肌丝蛋白、肌钙蛋白T阳性细胞,而诱导三代MSC肌丝蛋白阳性比例近20%,肌钙蛋白阳性比例约8%。RT-PCR显示诱导三代MSC 4周后有ANP和GATA-4心肌细胞特异基因表达。结论MSC能够在体外经5-aza诱导分化为心肌样细胞,具有向心肌细胞转化的潜力,是自体心肌细胞移植的一种良好供体。     

Pyroptosis in cardiovascular diseases: Pumping gasdermin on the fire

Pyroptosis is a form of programmed cell death associated with activation of inflammasomes and inflammatory caspases, proteolytic cleavage of gasdermin proteins (forming pores in the plasma membrane), and selective release of proinflammatory mediators. Induction of pyroptosis results in amplification of inflammation, contributing to the pathogenesis of chronic cardiovascular diseases such as atherosclerosis and diabetic cardiomyopathy, and acute cardiovascular events, such as thrombosis and myocardial infarction. While engagement of pyroptosis during sepsis-induced cardiomyopathy and septic shock is expected and well documented, we are just beginning to understand pyroptosis involvement in the pathogenesis of cardiovascular diseases with less defined inflammatory components, such as atrial fibrillation. Due to the danger that pyroptosis represents to cells within the cardiovascular system and the whole organism, multiple levels of pyroptosis regulation have evolved. Those include regulation of inflammasome priming, post-translational modifications of gasdermins, and cellular mechanisms for pore removal. While pyroptosis in macrophages is well characterized as a dramatic pro-inflammatory process, pyroptosis in other cell types within the cardiovascular system displays variable pathways and consequences. Furthermore, different cells and organs engage in local and distant crosstalk and exchange of pyroptosis triggers (oxidized mitochondrial DNA), mediators (IL-1β, S100A8/A9) and antagonists (IL-9). Development of genetic tools, such as Gasdermin D knockout animals, and small molecule inhibitors of pyroptosis will not only help us fully understand the role of pyroptosis in cardiovascular diseases but may result in novel therapeutic approaches inhibiting inflammation and progression of chronic cardiovascular diseases to reduce morbidity and mortality from acute cardiovascular events.