Kleefeldt Florian, Michelbach Peter, Rueckschloss Uwe, Ergün Süleyman, Wagner Nicole
Institute of Anatomy and Cell Biology, Julius-Maximilians-University Würzburg, 97070 Würzburg, Germany.
Cells. 2025 Jul 21;14(14):1119. doi: 10.3390/cells14141119.
Cardiac tissue engineering is a promising strategy to restore cardiac function in heart failure patients. Understanding the cardiac tissue architecture including the cardiac stroma is essential for developing not only advanced cardiac tissue engineering but also novel therapeutic strategies. One of the crucial components of the cardiac stroma is the myocardial vasculature. To enhance the spatial visualization of the cardiac stromal cytoarchitecture with a particular focus on myocardial vasculature, we performed 3D reconstructions of the murine cardiac micro vessels using Serial Block-Face Scanning Electron Microscopy (SBF-SEM). These analyses revealed that pericyte cell bodies were primarily oriented lengthwise and extended several cellular protrusions towards the endothelium. At capillary branching points, some pericytes made contact with both capillaries emerging from branching. In addition to pericytes that are completely encapsulated by the common basal lamina together with capillary endothelial cells, we identified other vascular-associated cells located outside this sheath. Based on marker expression, these cells were distinguished from fibroblasts and suggested to be telocytes. The vascular-associated cells formed electron-dense contact zones with endothelial cells, suggesting functional coupling between these both cell types. In conclusion, this study provides detailed three-dimensional visualizations of the cardiac stroma with a particular focus on cardiac microvasculature, offering enhanced insight into the cardiac stromal cytoarchitecture.
心脏组织工程是恢复心力衰竭患者心脏功能的一种很有前景的策略。了解包括心脏基质在内的心脏组织结构不仅对于开发先进的心脏组织工程至关重要，对于开发新的治疗策略也至关重要。心脏基质的关键组成部分之一是心肌脉管系统。为了增强对心脏基质细胞结构的空间可视化，特别关注心肌脉管系统，我们使用连续块面扫描电子显微镜（SBF-SEM）对小鼠心脏微血管进行了三维重建。这些分析表明，周细胞的细胞体主要沿纵向排列，并向内皮延伸出几个细胞突起。在毛细血管分支点，一些周细胞与从分支处出现的两条毛细血管都有接触。除了与毛细血管内皮细胞一起被共同基膜完全包裹的周细胞外，我们还鉴定出位于该鞘外的其他血管相关细胞。根据标记物表达，这些细胞与成纤维细胞不同，提示为端细胞。血管相关细胞与内皮细胞形成电子致密接触区，提示这两种细胞类型之间存在功能耦合。总之，本研究提供了对心脏基质的详细三维可视化，特别关注心脏微血管系统，增强了对心脏基质细胞结构的理解。
