State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (L.Y., F.H., Q.Z., D.L., S.F., M.Z., X.Z., B.Z., L.W.).
Shenzhen Key Laboratory of Cardiovascular Disease, Fuwai Hospital Chinese Academy of Medical Sciences, Bejing (Q.Z., B.Z., L.W.).
Circ Res. 2023 Jun 23;133(1):86-103. doi: 10.1161/CIRCRESAHA.123.322620. Epub 2023 May 30.
Reperfusion therapy is critical to myocardial salvage in the event of a myocardial infarction but is complicated by ischemia-reperfusion injury (IRI). Limited understanding of the spatial organization of cardiac cells, which governs cellular interaction and function, has hindered the search for targeted interventions minimizing the deleterious effects of IRI.
We used imaging mass cytometry to characterize the spatial distribution and dynamics of cell phenotypes and communities in the mouse left ventricle following IRI. Heart sections were collected from 12 cardiac segments (basal, mid-cavity, apical, and apex of the anterior, lateral, and inferior wall) and 8 time points (before ischemia [I-0H], and postreperfusion [R-0H, R-2H, R-6H, R-12H, R-1D, R-3D, R-7D]), and stained with 29 metal-isotope-tagged antibodies. Cell community analysis was performed on reconstructed images, and the most disease-relevant cell type and target protein were selected for intervention of IRI.
We obtained a total of 251 multiplexed images, and identified 197 063 single cells, which were grouped into 23 distinct cell communities based on the structure of cellular neighborhoods. The cellular architecture was heterogeneous throughout the ventricular wall and exhibited swift changes following IRI. Analysis of proteins with posttranslational modifications in single cells unveiled 13 posttranslational modification intensity clusters and highlighted increased H3K9me3 (tri-methylated lysine 9 of histone H3) as a key regulatory response in endothelial cells during the middle stage of IRI. Erasing H3K9 methylation, by silencing its methyltransferase or overexpressing its demethylase in isolated endothelial cells, attenuated cardiac dysfunction and pathological remodeling following IRI. in vitro, H3K9me3 binding significantly increased at endothelial cell function-related genes upon hypoxia, suppressing tube formation, which was rescued by inhibiting H3K9me3.
We mapped the spatiotemporal heterogeneity of cellular phenotypes in the adult heart upon IRI, and uncovered H3K9me3 in endothelial cells as a potential therapeutic target for alleviating pathological remodeling of the heart following myocardial IRI.
再灌注治疗对心肌梗死时的心肌挽救至关重要，但会引起缺血再灌注损伤（IRI）。由于对心脏细胞的空间组织认识有限，而这种组织决定了细胞间的相互作用和功能，因此阻碍了寻找靶向干预措施以最大程度减少 IRI 有害影响的研究。
我们使用成像质谱细胞术来描述 IRI 后小鼠左心室心脏细胞表型和细胞群落的空间分布和动态。在缺血前（I-0H）和再灌注后（R-0H、R-2H、R-6H、R-12H、R-1D、R-3D、R-7D）的 8 个时间点，从 12 个心脏节段（基底、中腔、心尖以及前壁、侧壁和下壁的顶点）采集心脏切片，并使用 29 种金属同位素标记的抗体进行染色。对重建图像进行细胞群落分析，并选择与疾病最相关的细胞类型和靶蛋白进行 IRI 干预。
我们总共获得了 251 个多重图像，并鉴定出 197063 个单细胞，这些细胞根据细胞邻里结构被分为 23 个不同的细胞群落。心室壁的细胞结构是异质的，并且在 IRI 后迅速发生变化。对单细胞中的翻译后修饰蛋白进行分析，揭示了 13 个翻译后修饰强度簇，并强调了 H3K9me3（组蛋白 H3 的赖氨酸 9 三甲基化）作为 IRI 中期内皮细胞中的关键调节反应。在分离的内皮细胞中沉默其甲基转移酶或过表达其去甲基酶，可消除 H3K9 甲基化，从而减轻 IRI 后的心脏功能障碍和病理性重塑。在体外，H3K9me3 结合在与内皮细胞功能相关的基因上显著增加，抑制管形成，而抑制 H3K9me3 可挽救管形成。
我们描绘了 IRI 后成年心脏细胞表型的时空异质性，并揭示了内皮细胞中的 H3K9me3 作为减轻心肌 IRI 后心脏病理性重塑的潜在治疗靶点。
