Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto, ON M5G 1L7, Canada.
Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1X8, Canada.
Cells. 2021 Oct 10;10(10):2713. doi: 10.3390/cells10102713.
Current understanding of mechanisms of ischemia-reperfusion-induced lung injury during lung preservation and transplantation is mainly based on clinical observations and animal studies. Herein, we used cell and systems biology approaches to explore these mechanisms at transcriptomics levels, especially by focusing on the differences between human lung endothelial and epithelial cells, which are crucial for maintaining essential lung structure and function. Human pulmonary microvascular endothelial cells and human lung epithelial cells were cultured to confluent, subjected to different cold ischemic times (CIT) to mimic static cold storage with preservation solution, and then subjected to warm reperfusion with a serum containing culture medium to simulate lung transplantation. Cell morphology, viability, and transcriptomic profiles were studied. Ischemia-reperfusion injury induced a CIT time-dependent cell death, which was associated with dramatic changes in gene expression. Under normal control conditions, endothelial cells showed gene clusters enriched in the vascular process and inflammation, while epithelial cells showed gene clusters enriched in protein biosynthesis and metabolism. CIT 6 h alone or after reperfusion had little effect on these phenotypic characteristics. After CIT 18 h, protein-biosynthesis-related gene clusters disappeared in epithelial cells; after reperfusion, metabolism-related gene clusters in epithelial cells and multiple gene clusters in the endothelial cells also disappeared. Human pulmonary endothelial and epithelial cells have distinct phenotypic transcriptomic signatures. Severe cellular injury reduces these gene expression signatures in a cell-type-dependent manner. Therapeutics that preserve these transcriptomic signatures may represent new treatment to prevent acute lung injury during lung transplantation.
目前对肺保存和移植过程中缺血再灌注引起的肺损伤机制的理解主要基于临床观察和动物研究。在此，我们采用细胞和系统生物学方法在转录组水平上探索这些机制，特别是重点关注对维持肺基本结构和功能至关重要的人肺内皮细胞和上皮细胞之间的差异。培养人肺微血管内皮细胞和人肺上皮细胞至汇合状态，用保存液模拟静态冷保存进行不同的冷缺血时间（CIT）处理，然后用含血清的培养基进行温再灌注以模拟肺移植。研究了细胞形态、活力和转录组谱。缺血再灌注损伤诱导了 CIT 时间依赖性细胞死亡，这与基因表达的剧烈变化有关。在正常对照条件下，内皮细胞显示出富含血管过程和炎症的基因簇，而上皮细胞显示出富含蛋白质生物合成和代谢的基因簇。单独的 CIT 6 小时或再灌注后对这些表型特征影响不大。CIT 18 小时后，上皮细胞中与蛋白质生物合成相关的基因簇消失；再灌注后，上皮细胞中与代谢相关的基因簇以及内皮细胞中的多个基因簇也消失。人肺内皮和上皮细胞具有独特的表型转录组特征。严重的细胞损伤以细胞类型依赖性的方式减少这些基因表达特征。保留这些转录组特征的治疗方法可能代表预防肺移植过程中急性肺损伤的新治疗方法。
