Zhang Zhao, Gao Bruce Z, Ye Tong
Department of Bioengineering, Clemson University, Clemson, SC 29634, USA.
Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC 29425, USA.
Photonics. 2024 Jun;11(6). doi: 10.3390/photonics11060533. Epub 2024 Jun 3.
Within the myocardium, cardiomyocytes reside in a complex and dynamic extracellular matrix (ECM) consisting of a basement membrane (BM) and interstitial matrix. The interactions between cardiomyocytes and the myocardial ECM play a critical role in maintaining cardiac geometry and function throughout cardiac development and in adult hearts. Understanding how the structural changes of the myocardial ECM affect cardiomyocyte function requires knowledge of pericellular structures. These structures are of a size beyond the resolution of conventional optical microscopy. Here, we demonstrated multi-scale and multi-aspect characterization of the cardiomyocyte microenvironment in myocardial tissue sections using multimodal stimulated emission depletion (STED) microscopy. Second harmonic generation and autofluorescence facilitated multiplexed imaging, enabling the interpretation of protein distribution in 3D. STED imaging modality revealed BM structures of cardiomyocytes and myocardial capillaries at the subdiffractional level. Moreover, meaningful measurements retrieved from acquired images, such as sarcomere length and capillary density, enabled quantitative assessment of myocardial structures.
在心肌组织中，心肌细胞存在于由基底膜（BM）和间质基质组成的复杂且动态的细胞外基质（ECM）中。心肌细胞与心肌细胞外基质之间的相互作用在心脏发育全过程以及成年心脏中维持心脏形态和功能方面起着关键作用。要了解心肌细胞外基质的结构变化如何影响心肌细胞功能，就需要了解细胞周围结构。这些结构的大小超出了传统光学显微镜的分辨率。在此，我们利用多模态受激辐射损耗（STED）显微镜展示了心肌组织切片中心肌细胞微环境的多尺度和多方面特征。二次谐波产生和自发荧光促进了多重成像，能够解读三维空间中的蛋白质分布。STED成像模式揭示了心肌细胞和心肌毛细血管在亚衍射水平的基底膜结构。此外，从获取的图像中获得的有意义的测量值，如肌节长度和毛细血管密度，能够对心肌结构进行定量评估。
