title: Expression of the TAL1/SCL transcription factor in physiological and pathological vascular processes.
abstract: The TAL1/SCL transcription factor is essential for haematopoietic commitment and vascular remodelling during embryonic development. To help clarify its role in postnatal vascular processes, we characterized the expression of mouse Tal1 protein by immunocytochemistry in several experimental models of blood vessel formation. In adult mice, Tal1 protein was expressed in rare microvascular endothelial cells and in extravascular cells provisionally identified as endothelial progenitors from their morphology, proximity to vessels and expression of vascular endothelial growth factor receptor-2. The number of Tal1-expressing endothelial cells increased significantly but transiently in all the models-hormone-induced ovulation, wound healing and tumour development. Finally, Tal1 protein was detected in the nuclei of newly formed lymphatic endothelial cells in tumour-bearing animals. These results show that TAL1 is expressed by vascular endothelial cells and endothelial progenitors at sites of physiological and pathological neovascularization and suggest a role for this transcription factor in adult vasculogenesis. This work also provides the first evidence for TAL1 expression in lymphangiogenesis.
authors.affiliation: Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
authors.forename: T
authors.initials: T
authors.lastname: Tang
authors.forename: Y
authors.initials: Y
authors.lastname: Shi
authors.forename: S R
authors.initials: SR
authors.lastname: Opalenik
authors.forename: D M
authors.initials: DM
authors.lastname: Brantley-Sieders
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: J M
authors.initials: JM
authors.lastname: Davidson
authors.forename: S J
authors.initials: SJ
authors.lastname: Brandt
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000032:analysis*; D045744:Cell Line, Tumor; D042783:Endothelial Cells / Q000737:chemistry*; D004730:Endothelium, Vascular / Q000737:chemistry; D005260:Female; D006062:Gonadotropins / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000737:chemistry*; D007150:Immunohistochemistry / Q000379:methods; D007515:Islets of Langerhans / Q000737:chemistry; D042583:Lymphangiogenesis / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008833:Microcirculation / Q000502:physiology; D023421:Models, Animal; D009389:Neovascularization, Pathologic / Q000503:physiopathology; D018919:Neovascularization, Physiologic / Q000502:physiology; D010053:Ovary / Q000737:chemistry; D010060:Ovulation / Q000187:drug effects / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000032:analysis*; D000073942:T-Cell Acute Lymphocytic Leukemia Protein 1; D014599:Uterus / Q000737:chemistry; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000032:analysis; D014945:Wound Healing / Q000502:physiology
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D006062:Gonadotropins; D011518:Proto-Oncogene Proteins; D000073942:T-Cell Acute Lymphocytic Leukemia Protein 1; D040301:Vascular Endothelial Growth Factor Receptor-2; C489366:Tal1 protein, mouse