Limits...
EphB4 forward signalling regulates lymphatic valve development.

Zhang G, Brady J, Liang WC, Wu Y, Henkemeyer M, Yan M - Nat Commun (2015)

Bottom Line: Here we show that EphB4-dependent forward signalling regulates lymphatic valve development, a process previously thought to be regulated by ephrinB2-dependent reverse signalling.We develop antibodies that selectively target EphB4 and ephrinB2.Furthermore, a chemical genetic approach is used to unequivocally show that the kinase activity of EphB4 is essential for lymphatic valve development.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Oncology, Division of Research, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.

ABSTRACT
Bidirectional signalling is regarded as a notable hallmark of the Eph-ephrin signalling system: Eph-dependent forward signalling in Eph-expressing cells and ephrin-dependent reverse signalling in Ephrin-expressing cells. The notion of ephrin-dependent reverse signalling derives from genetic experiments utilizing mice carrying mutations in the intracellular region of ephrinBs. Here we show that EphB4-dependent forward signalling regulates lymphatic valve development, a process previously thought to be regulated by ephrinB2-dependent reverse signalling. We develop antibodies that selectively target EphB4 and ephrinB2. We find that mice bearing genetically altered cytoplasmic region of ephrinB2 have significantly altered EphB4-dependent forward signalling. Selective inhibition of EphB4 using a functional blocking antibody results in defective lymphatic valve development. Furthermore, a chemical genetic approach is used to unequivocally show that the kinase activity of EphB4 is essential for lymphatic valve development.

Show MeSH

Related in: MedlinePlus

Anti-ephrinB2 causes dramatic lymphatic defects in neonatal mice.Treatment was started at P1 and mice were examined on P7. Scale bar, 1 mm. (a) Chylothorax in α-ephrinB2-treated mice. Exterior (b) and interior (c) views of the leg skins following injection of FITC-dextran into the hindlimb footpad. The main lymphatic collecting vessels are marked (arrowheads). Anti-ephrinB2 (α-ephrinB2)-treated animals exhibited abnormal outflow of FITC-dextran from collecting vessels to the pre-collector vessel branches. (d) Collecting vessels running between the lumbar (LLN) lymph nodes and renal lymph nodes (RLN). In control (Ctrl) mice, only a pair of collecting lymphatic vessel trunks was highlighted by FITC-dextran (left). In anti -ephrinB2-treated animals (right), FITC-dextran visibly diffused into the surrounding lymphatic network.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4403310&req=5

f2: Anti-ephrinB2 causes dramatic lymphatic defects in neonatal mice.Treatment was started at P1 and mice were examined on P7. Scale bar, 1 mm. (a) Chylothorax in α-ephrinB2-treated mice. Exterior (b) and interior (c) views of the leg skins following injection of FITC-dextran into the hindlimb footpad. The main lymphatic collecting vessels are marked (arrowheads). Anti-ephrinB2 (α-ephrinB2)-treated animals exhibited abnormal outflow of FITC-dextran from collecting vessels to the pre-collector vessel branches. (d) Collecting vessels running between the lumbar (LLN) lymph nodes and renal lymph nodes (RLN). In control (Ctrl) mice, only a pair of collecting lymphatic vessel trunks was highlighted by FITC-dextran (left). In anti -ephrinB2-treated animals (right), FITC-dextran visibly diffused into the surrounding lymphatic network.

Mentions: The antibodies we have generated target both human and mouse orthologues, allowing us to assess their in vivo activities in mouse models. Neonatal mice dosed with anti-ephrinB2 at postnatal day 1 (P1) usually (90%) died by P8. Examination of anti-EphrinB2-treated animals revealed apparent chylothorax, a condition where chyle from the thoracic duct effuses into the pleural space (Fig. 2a), indicating compromised lymphatic vasculature. Assessment of lymphatic function by examining the uptake and transport of large-molecule-weight fluorescent dye further confirmed the lymphatic defects (Fig. 2b–d).


EphB4 forward signalling regulates lymphatic valve development.

Zhang G, Brady J, Liang WC, Wu Y, Henkemeyer M, Yan M - Nat Commun (2015)

Anti-ephrinB2 causes dramatic lymphatic defects in neonatal mice.Treatment was started at P1 and mice were examined on P7. Scale bar, 1 mm. (a) Chylothorax in α-ephrinB2-treated mice. Exterior (b) and interior (c) views of the leg skins following injection of FITC-dextran into the hindlimb footpad. The main lymphatic collecting vessels are marked (arrowheads). Anti-ephrinB2 (α-ephrinB2)-treated animals exhibited abnormal outflow of FITC-dextran from collecting vessels to the pre-collector vessel branches. (d) Collecting vessels running between the lumbar (LLN) lymph nodes and renal lymph nodes (RLN). In control (Ctrl) mice, only a pair of collecting lymphatic vessel trunks was highlighted by FITC-dextran (left). In anti -ephrinB2-treated animals (right), FITC-dextran visibly diffused into the surrounding lymphatic network.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4403310&req=5

f2: Anti-ephrinB2 causes dramatic lymphatic defects in neonatal mice.Treatment was started at P1 and mice were examined on P7. Scale bar, 1 mm. (a) Chylothorax in α-ephrinB2-treated mice. Exterior (b) and interior (c) views of the leg skins following injection of FITC-dextran into the hindlimb footpad. The main lymphatic collecting vessels are marked (arrowheads). Anti-ephrinB2 (α-ephrinB2)-treated animals exhibited abnormal outflow of FITC-dextran from collecting vessels to the pre-collector vessel branches. (d) Collecting vessels running between the lumbar (LLN) lymph nodes and renal lymph nodes (RLN). In control (Ctrl) mice, only a pair of collecting lymphatic vessel trunks was highlighted by FITC-dextran (left). In anti -ephrinB2-treated animals (right), FITC-dextran visibly diffused into the surrounding lymphatic network.
Mentions: The antibodies we have generated target both human and mouse orthologues, allowing us to assess their in vivo activities in mouse models. Neonatal mice dosed with anti-ephrinB2 at postnatal day 1 (P1) usually (90%) died by P8. Examination of anti-EphrinB2-treated animals revealed apparent chylothorax, a condition where chyle from the thoracic duct effuses into the pleural space (Fig. 2a), indicating compromised lymphatic vasculature. Assessment of lymphatic function by examining the uptake and transport of large-molecule-weight fluorescent dye further confirmed the lymphatic defects (Fig. 2b–d).

Bottom Line: Here we show that EphB4-dependent forward signalling regulates lymphatic valve development, a process previously thought to be regulated by ephrinB2-dependent reverse signalling.We develop antibodies that selectively target EphB4 and ephrinB2.Furthermore, a chemical genetic approach is used to unequivocally show that the kinase activity of EphB4 is essential for lymphatic valve development.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Oncology, Division of Research, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.

ABSTRACT
Bidirectional signalling is regarded as a notable hallmark of the Eph-ephrin signalling system: Eph-dependent forward signalling in Eph-expressing cells and ephrin-dependent reverse signalling in Ephrin-expressing cells. The notion of ephrin-dependent reverse signalling derives from genetic experiments utilizing mice carrying mutations in the intracellular region of ephrinBs. Here we show that EphB4-dependent forward signalling regulates lymphatic valve development, a process previously thought to be regulated by ephrinB2-dependent reverse signalling. We develop antibodies that selectively target EphB4 and ephrinB2. We find that mice bearing genetically altered cytoplasmic region of ephrinB2 have significantly altered EphB4-dependent forward signalling. Selective inhibition of EphB4 using a functional blocking antibody results in defective lymphatic valve development. Furthermore, a chemical genetic approach is used to unequivocally show that the kinase activity of EphB4 is essential for lymphatic valve development.

Show MeSH
Related in: MedlinePlus