VCAM-1 expression in adult hematopoietic and nonhematopoietic cells is controlled by tissue-inductive signals and reflects their developmental origin

• Published in: Blood 2005-07, Vol.106 (1), p.86-94
• Main Authors: Ulyanova, Tatiana, Scott, Linda M., Priestley, Gregory V., Jiang, Yi, Nakamoto, Betty, Koni, Pandelakis A., Papayannopoulou, Thalia
• Format: Article
• Language: English
• Subjects: Age Factors; Animals; Biological and medical sciences; Bone Marrow Cells - cytology; Bone Marrow Cells - physiology; Cell differentiation, maturation, development, hematopoiesis; Cell physiology; Cells, Cultured; Chemokine CXCL12; Chemokines, CXC - metabolism; Endothelial Cells - cytology; Endothelial Cells - physiology; Female; Fibroblasts - cytology; Fibroblasts - physiology; Fundamental and applied biological sciences. Psychology; Hematopoiesis; Hematopoiesis - physiology; Lymphocytes - cytology; Lymphocytes - physiology; Lymphoid Tissue - cytology; Lymphoid Tissue - physiology; Male; Mice; Mice, Transgenic; Molecular and cellular biology; Myeloid Cells - cytology; Myeloid Cells - physiology; RNA, Messenger - analysis; Signal Transduction - physiology; Spleen - cytology; Spleen - physiology; Vascular Cell Adhesion Molecule-1 - genetics; Vascular Cell Adhesion Molecule-1 - metabolism
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2004-09-3417

Although expression of vascular cell adhesion molecule 1 (VCAM-1) in endothelial cells and its functional implications have been previously appreciated, VCAM-1 expression in other than endothelial cells, especially hematopoietic cells, has been recently recognized and has not been explored in detail. Using normal mice and mice with a conditional ablation of VCAM-1 through a Tie2-driven cre transgene, we have studied the biodistribution and the pattern of VCAM-1 expression in circulating versus tissue-residing cells before and after their enforced mobilization. In the normal mouse, both at basal hematopoiesis or following mobilization, VCAM-1 expression is confined to myeloid cells residing in hematopoietic tissues, whereas free cells in circulation or in body cavities are devoid of VCAM-1 messenger RNA (mRNA) and protein. However, following culture, proliferating myeloid cells, but not lymphoid cells, express VCAM-1. In the VCAM-1–ablated mouse, there is an increase in circulating progenitors as a consequence of their ongoing release from bone marrow, a process enhanced by splenectomy. We postulate that the main mechanism leading to their release is the ablation of VCAM-1 by fibroblastic and by endothelial cells. Ablation of VCAM-1 in fibroblasts by Tie2-driven cre is a novel finding and likely denotes their developmental ancestry by Tie2-expressing (mesenchymal?) progenitor cells during development.