Visualization of lymphatic vessels through NF-κB activity

Abstract

The molecular biology of lymphatics is only rudimentary owing to the long-standing absence of specific markers, and scanty is the information regarding bladder lymphatic vessels. By using mice with a reporter gene for nuclear factor B (NF-B) activity (B-lacZ) in combination with immunohistochemical staining with a specific lymphatic marker (LYVE-1), we show, for the first time, that NF-B is constitutively active in lymphatic endothelium in the urinary bladder, uterus, intestine, heart, and airways. Tie2-lacZ mice confirmed that the structures observed in B-lacZ mice were not blood vessels. In addition, acute instillation of lipopolysaccharide (LPS) or tumor necrosis factor ␣ (TNF-␣) into the B-lacZ mouse bladder revealed the capacity of this transgenic in reporting inducible NF-B activity. Our findings demonstrate an overriding constitutive NF-B activity in the lymphatic system. They also provide a working model for detecting lymphatic vessels and evoke testable hypotheses regarding the role of lymphatic vessels in health and disease. (Blood. 2004;104:3228-3230)

Toll-like receptor 4 in lymphatic endothelial cells contributes to LPS-induced lymphangiogenesis by chemotactic recruitment of macrophages

“…26 Upon NF-B activation in these mice, one of the NF-B subunits, p65, translocates to the nucleus and binds the p105 promoter, which induces lacZ expression. Consistent with a previous report, 33 NF-B was predominantly expressed in LYVE-1 ϩ lymphatic capillaries, but not in the blood vessel of the diaphragm (Figure S4 top panel). Moreover, the LPS-induced, newly developed branching lymphatic vessels also expressed NF-B (Figure S4 bottom panel).…”

Visualization of lymphatic vessels by Prox1-promoter directed GFP reporter in a bacterial artificial chromosome-based transgenic mouse

“…Alternatively, nuclear factor-B activity has been fortuitously associated with lymphatic vessels. 25 This LacZ reporter-based model, however, has drawbacks of ubiquitous nuclear factor-B expression in other cell types under various physiologic and pathologic conditions. Despite the creation of the Prox1-GFP transgenic mouse as part of the GENSAT effort many years ago, its experimental value in vascular research has never been explored to date.…”

Lineage tracing demonstrates the venous origin of the mammalian lymphatic vasculature

“…The interaction of Tie2 with its ligand angiopoietin-1 (Ang1) helps remodel and stabilize primitive vasculature (Sato et al 1993;Suri et al 1996). The phenotype of mice lacking another Tie2 ligand, Ang2, suggested that Tie2 also functions during postnatal lymphatic remodeling (Gale et al 2002); however, its expression has not been observed in LECs (Motoike et al 2000;Saban et al 2004;Wilting et al 2006), except in restricted regions of adult lymphatics Tammela et al 2005). Hence, Tie2-independent, integrin-mediated signaling might mediate angiopoietin function in the lymphatic vasculature .…”