Matrix Biology Program, Benaroya Research Institute at Virginia Mason, Seattle, Washington, USA; Departments of Pathology and Surgery, University of Washington School of Medicine, Seattle, Washington, USA.
Matrix Biology Program, Benaroya Research Institute at Virginia Mason, Seattle, Washington, USA; Departments of Pathology and Surgery, University of Washington School of Medicine, Seattle, Washington, USA
Stem Cells Transl Med. 2014 Jun;3(6):734-44. doi: 10.5966/sctm.2013-0189. Epub 2014 Apr 15.
Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) can regenerate infarcted myocardium. However, when implanted into acutely infarcted hearts, few cells survive the first week postimplant. To improve early graft survival, hESC-CMs were pretreated with cobalt protoporphyrin (CoPP), a transcriptional activator of cytoprotective heme oxygenase-1 (HO-1). When hESC-CMs were challenged with an in vitro hypoxia/reoxygenation injury, mimicking cell transplantation into an ischemic site, survival was significantly greater among cells pretreated with CoPP versus phosphate-buffered saline (PBS)-pretreated controls. Compared with PBS-pretreated cells, CoPP-pretreated hESC-CM preparations exhibited higher levels of HO-1 expression, Akt phosphorylation, and vascular endothelial growth factor production, with reduced apoptosis, and a 30% decrease in intracellular reactive oxygen species. For in vivo translation, 1 × 10(7) hESC-CMs were pretreated ex vivo with CoPP or PBS and then injected intramyocardially into rat hearts immediately following acute infarction (permanent coronary ligation). At 1 week, hESC-CM content, assessed by quantitative polymerase chain reaction for human Alu sequences, was 17-fold higher in hearts receiving CoPP- than PBS-pretreated cells. On histomorphometry, cardiomyocyte graft size was 2.6-fold larger in hearts receiving CoPP- than PBS-pretreated cells, occupying up to 12% of the ventricular area. Vascular density of host-perfused human-derived capillaries was significantly greater in grafts composed of CoPP- than PBS-pretreated cells. Taken together, these experiments demonstrate that ex vivo pretreatment of hESC-CMs with a single dose of CoPP before intramyocardial implantation more than doubled resulting graft size and improved early graft vascularization in acutely infarcted hearts. These findings open the door for delivery of these, or other, stem cells during acute interventional therapy following myocardial infarction or ischemia.
人类胚胎干细胞来源的心肌细胞（hESC-CMs）可以再生梗死的心肌。然而，当将其植入急性梗死的心脏时，只有少数细胞能在植入后的第一周存活下来。为了提高早期移植物的存活率，用钴原卟啉（CoPP）预处理 hESC-CMs，这是一种细胞保护性血红素加氧酶-1（HO-1）的转录激活剂。当 hESC-CMs 受到体外缺氧/复氧损伤的挑战时，这种损伤模拟了细胞移植到缺血部位，与用磷酸盐缓冲盐水（PBS）预处理的对照组相比，用 CoPP 预处理的细胞的存活率明显更高。与 PBS 预处理的细胞相比，CoPP 预处理的 hESC-CM 制剂表现出更高水平的 HO-1 表达、Akt 磷酸化和血管内皮生长因子产生，细胞凋亡减少，细胞内活性氧减少 30%。为了进行体内翻译，将 1×10（7）个 hESC-CMs 离体用 CoPP 或 PBS 预处理，然后在急性梗死（永久性冠状动脉结扎）后立即心肌内注射到大鼠心脏中。在 1 周时，通过人 Alu 序列的定量聚合酶链反应评估 hESC-CM 含量，接受 CoPP 预处理的心脏中的 hESC-CM 含量比接受 PBS 预处理的心脏高 17 倍。在组织形态计量学上，接受 CoPP 预处理的心脏中的心肌移植物大小比接受 PBS 预处理的心脏大 2.6 倍，占据心室面积的 12%。由 CoPP 预处理的细胞组成的移植物中的宿主灌注的人源性毛细血管的血管密度明显大于由 PBS 预处理的细胞组成的移植物。总的来说，这些实验表明，在心肌内注射前对 hESC-CMs 进行单次 CoPP 预处理可使移植物的体积增加一倍以上，并改善急性梗死心脏中早期移植物的血管化。这些发现为在心肌梗死或缺血后的急性介入治疗期间输送这些或其他干细胞开辟了道路。
