CeMM Principal Investigator
Laura de Rooij
Endothelial cells (ECs) line the interior surface of all blood vessels, and are essential for regulation of vascular tone, vessel growth, inflammation, permeability, and coagulation. During the process of aging ECs can become dysfunctional, which plays a major role in the etiology of numerous clinical disorders of advancing age.
Our group aims to combine single-cell omics and functional vascular assays to increase our fundamental understanding of EC heterogeneity and its role in vascular aging. We intend to assess the degree of transcriptomic and functional EC heterogeneity in health, but also in the context of healthy aging and aging-associated disease. Our overarching goal is to explore the translational relevance of ECs and specific EC phenotypes for the diagnosis and treatment of vascular aging.
Characterizing endothelial cells one cell at a time
The single-cell era has led to the emergence of a multitude of studies and technologies that revolutionized our understanding of cellular heterogeneity from a physiological and pathophysiological viewpoint. Recent single-cell omics studies have compellingly revealed that ECs lining blood vessels are transcriptomically heterogeneous, encompassing several subtypes with distinct gene expression profiles related to their tissue-of-origin or disease setting. From an aging point-of-view, however, the degree and role of EC heterogeneity remains poorly understood. We thus aim to obtain a high-resolution view of the aging endothelium by leveraging single-cell technologies. Questions that fuel our research are: What is the degree of EC heterogeneity in health, and how does this change when we age? Can we identify marker genes that consistently change in ECs across organs and tissues in the human body? What are the transcriptional orchestrators of endothelial aging?
Non-invasive profiling of the aging human vasculature
As gaining insights into mechanisms of healthy and pathological vascular aging often requires invasive assessments (e.g., biopsies) that are impractical in healthy human individuals, we aim to unravel novel ways to non-invasively infer the age and health status of our vascular endothelium. In that light, circulating endothelial cells (CECs) in our blood represent an easy-to-access cell population possibly involved in development, repair, regeneration and aging of the vasculature. Ever since their discovery, CECs have however been plagued with controversy as to their identity, functional relevance, and heterogeneity, all precluding their translational use. Our group thus aspires to deeply characterize the transcriptomic landscape and function of this rare cell population in human blood, to gain a comprehensive understanding of their complexity and abundance in young and aged individuals.
In vitro modeling of circulation endothelial cell function
Our group will use various in vitro approaches to study the overall function of ECs and CECs, and the possibility of their ex vivo expansion while maintaining their transcriptomic phenotype. We will make use of human induced pluripotent stem cell (iPSC) as well as peripheral blood derived EC culture setups for aging-associated gene perturbation studies. Moreover, the usage of perfusable 3D in vitro vascular model systems will be explored to functionally characterize (circulating) ECs in a physiologically relevant, human context. Altogether, we aim to answer several outstanding questions, including if and how CECs can home to areas of vessel injury, whether/how they can aid in repair of injured vessels, and how aging compromises the overall function and angiogenic abilities of both ECs and CECs.
Laura de Rooij studied biomedical sciences at the University of Amsterdam (The Netherlands). She then joined the Stem Cell and Cancer Research Institute at McMaster University in Hamilton (Canada), where she studied the role of RNA-binding proteins in leukemic stem cells via an in vivo two-step CRISPR-Cas9-mediated screening approach. For her postdoctoral studies, she returned to Europe to work under the mentorship of Professor Carmeliet in the lab of Angiogenesis and Vascular Metabolism at VIB-KU Leuven (Belgium). There, she led and contributed to numerous single-cell transcriptome atlases of endothelial cells, generated from a diverse range of tissues, preclinical models, and clinical patient material in health and disease. Her studies have shed new light on the degree of vessel subtype heterogeneity in different tissues, as well as the altered composition and rewired molecular circuitries of endothelial cell subtypes in disease. Moreover, her efforts led to the discovery of previously unknown vascular subtypes and functions, including endothelial cells—with a lipid-processing phenotype and potential prognostic relevance in breast cancer—and endothelial cells with a putative profibrotic function in COVID-19. Laura de Rooij joined CeMM as principal investigator in September 2022. Her lab focuses on deciphering the transcriptomic landscape and the role of circulating endothelial cells in health and aging.
de Rooij, L.P.M.H.*, Becker, L.M.* et al. The pulmonary vasculature in lethal COVID-19 and idiopathic pulmonary fibrosis at single cell resolution. Cardiovasc Res. 2022 Aug 23:cvac139. doi: 10.1093/cvr/cvac139. (abstract)
Geldhof V, de Rooij L.P.M.H., Sokol L., Amersfoort J., De Schepper M., Rohlenova K., Hoste G., Vanderstichele A., Delsupehe A.M., Isnaldi E., Dai N., Taverna F., Khan S., Truong A.K., Teuwen L.A., Richard F., Treps L., Smeets A., Nevelsteen I., Weynand B., Vinckier S., Schoonjans L., Kalucka J., Desmedt C., Neven P., Mazzone M., Floris G., Punie K., Dewerchin M., Eelen G., Wildiers H., Li X., Luo Y., Carmeliet P. Single cell atlas identifies lipid-processing and immunomodulatory endothelial cells in healthy and malignant breast. Nat Commun. 2022 Sep 20;13(1):5511. (abstract)
de Rooij, L.P.M.H., Becker, L.M. & Carmeliet, P. A role for the vascular endothelium in post-acute COVID-19? Circulation. 2022 May 17;145(20):1503-1505. (abstract)
Becker, L.M.*, Chen, S.H.*, Rodor, J.*, de Rooij, L.P.M.H.* et al. Deciphering endothelial heterogeneity in health and disease at single cell resolution: progress and perspectives. Cardiovasc Res. 2022 Feb 18:cvac018. (abstract)
Vujovic, A.*, de Rooij, L.P.M.H.* et al. A two-step in vivo CRISPR-Cas9 screening unveils pervasive RNA-binding protein dependencies for leukemic stem cells and identifies ELAVL1 as a therapeutic target. bioRxiv 2022.06.11.494613. (abstract)
Teuwen, L.A., de Rooij, L.P.M.H. et al. Tumor vessel co-option probed by single-cell analysis. Cell Rep. 2021 Jun 15;35(11):109253. (abstract)
Kalucka, J.*, de Rooij, L.P.M.H.*, Goveia, J.* et al. A single cell transcriptome atlas of murine endothelial cells. Cell. 2020 Feb 20;180(4):764-779.e20. (abstract)
Goveia, J. et al. An Integrated Gene Expression Landscape Profiling Approach to Identify Lung Tumor Endothelial Cell Heterogeneity and Angiogenic Candidates. Cancer Cell. 2020 Jan 13;37(1):21-36.e13. Erratum in: Cancer Cell. 2020 Mar 16;37(3):421. (abstract)
Khan S et al. EndoDB: a database of endothelial cell transcriptomics data. Nucleic Acids Res. 2019 Jan 8;47(D1):D736-D744. (abstract)
*joint first authorship