Studies on vascular cell heterogeneity

<p dir="ltr">Vascular endothelial cells (ECs) and pericytes are core components of the vascular system, and their organ-specific and species-specific heterogeneity is of great significance for maintaining vascular homeostasis, regulating organ function, and mediating pathological processes. Focusing on vascular cell heterogeneity and cross-species differences, this study centered on four core research directions, systematically exploring the molecular characteristics and functional differences of vascular ECs and pericytes by adopting experimental techniques such as single-cell RNA sequencing (scRNA-seq), in situ hybridization, and in vitro cell culture, combined with integrated analysis of public datasets.</p><p dir="ltr">In the first study, scRNA-seq analysis was performed on ECs from 11 mouse tissues, leading to the identification of 928 differentially expressed genes between fenestrated and non-fenestrated ECs. A specific gene was found to be a specific marker of fenestrated ECs, and its silencing resulted in the loss of EC fenestrations, confirming its crucial regulatory role in fenestration formation. In the second study, eight scRNA-seq datasets of mouse aortic ECs were integrated, which broke the traditional cognition that "all aortic ECs originate from the luminal surface". Main EC subtypes were identified: one derived from the lumen (Cytl1-positive) and the other from peri-aortic microvessels (Gpihbp1-positive), with corresponding marker gene lists and an accessible online database established. In the third study, four scRNA-seq datasets of adult mouse and human brain pericytes were integrated. The results showed that the transcriptomes of mouse and human brain pericytes were generally conserved, but there were 206 differentially expressed orthologous genes, among which 91 were specifically highly expressed in human brain pericytes and 115 in mouse brain pericytes. Notably, several human neurological disease-related genes were only expressed in human brain pericytes. In the fourth study, systematic analysis of the transcriptomes of mouse and human blood-brain barrier (BBB) capillary ECs revealed significant species differences, with 260 human-specific enriched genes and 397 mouse-specific enriched genes identified. Genes of the solute carrier (SLC) transporter family showed significant differences, and human-specific genes such as THSD4 was validated by independent datasets.</p><p dir="ltr">This study systematically reveals the molecular heterogeneity characteristics and cross-species differences of vascular ECs and pericytes, filling the knowledge gaps in related fields. It provides important molecular basis and experimental resources for basic research on vascular biology, as well as clinical translational research on vascular diseases and neurological disorders, and has important significance for optimizing mouse models and developing targeted therapeutic strategies.</p><p dir="ltr">Keywords: Vascular endothelial cell; Pericyte; Cell heterogeneity; Endothelial fenestration; Blood-brain barrier; Cross-species comparison; Single-cell RNA sequencing</p><h3 dir="ltr">List of scientific papers</h3><p dir="ltr">I. <b>Yuyang Miao</b>, Marie Jeansson, Lars Muhl, Liqun He, Christer Betsholtz. Elucidating the mechanism of endothelial cell fenestrations. [Manuscript]</p><p dir="ltr">II. Liqun He #, Riikka Pietilä #, <b>Yuyang Miao</b> #, Elisa Vazquez- Liebanas, Marie Jeansson, Loren G Fong, Stephen G Young, Maarja Andaloussi Mäe, Lars Muhl, Christer Betsholtz. Distinguishing subtypes of endothelial cells in the mouse aorta. Proc Natl Acad Sci U S A. 2025;122(49):e2525755122. <a href="https://doi.org/10.1073/pnas.2525755122" rel="noreferrer" target="_blank">https://doi.org/10.1073/pnas.2525755122</a></p><p dir="ltr">III. <b>Yuyang Miao</b>, Weihan Li, Marie Jeansson, Maarja Andaloussi Mäe, Lars Muhl, Liqun He. Different gene expression patterns between mouse and human brain pericytes revealed by single-cell/nucleus RNA sequencing. Vascul Pharmacol. 2024;157:107434. <a href="https://doi.org/10.1016/j.vph.2024.107434" rel="noreferrer" target="_blank">https://doi.org/10.1016/j.vph.2024.107434</a></p><p dir="ltr">IV. <b>Yuyang Miao</b>, Jianhao Wang, Weihan Li, Maarja Andaloussi Mäe, Marie Jeansson, Lars Muhl, Liqun He. Distinct gene expression profiles in blood-brain barrier capillary endothelial cells between mice and humans. Microvasc Res. Published online March 12, 2026. <a href="https://doi.org/10.1016/j.mvr.2026.104933" rel="noreferrer" target="_blank">https://doi.org/10.1016/j.mvr.2026.104933</a></p>