VEGFD regulates blood vascular development by modulating SOX18 activity

Blood ◽  
2014 ◽  
Vol 123 (7) ◽  
pp. 1102-1112 ◽  
Author(s):  
Tam Duong ◽  
Katarzyna Koltowska ◽  
Cathy Pichol-Thievend ◽  
Ludovic Le Guen ◽  
Frank Fontaine ◽  
...  

Key Points Haploinsufficiency of Sox18 reveals an important role for VEGFD in regulating blood vascular development in vivo in vertebrates. VEGFD acts through mitogen-activated protein kinase kinase–extracellular signal-regulated kinase to modulate the activity and nuclear concentration of endothelial-specific transcription factor SOX18.

1998 ◽  
Vol 18 (4) ◽  
pp. 1946-1955 ◽  
Author(s):  
Jun Xing ◽  
Jon M. Kornhauser ◽  
Zhengui Xia ◽  
Elizabeth A. Thiele ◽  
Michael E. Greenberg

ABSTRACT The mechanisms by which growth factor-induced signals are propagated to the nucleus, leading to the activation of the transcription factor CREB, have been characterized. Nerve growth factor (NGF) was found to activate multiple signaling pathways that mediate the phosphorylation of CREB at the critical regulatory site, serine 133 (Ser-133). NGF activates the extracellular signal-regulated kinase (ERK) mitogen-activated protein kinases (MAPKs), which in turn activate the pp90 ribosomal S6 kinase (RSK) family of Ser/Thr kinases, all three members of which were found to catalyze CREB Ser-133 phosphorylation in vitro and in vivo. In addition to the ERK/RSK pathway, we found that NGF activated the p38 MAPK and its downstream effector, MAPK-activated protein kinase 2 (MAPKAP kinase 2), resulting in phosphorylation of CREB at Ser-133. Inhibition of either the ERK/RSK or the p38/MAPKAP kinase 2 pathway only partially blocked NGF-induced CREB Ser-133 phosphorylation, suggesting that either pathway alone is sufficient for coupling the NGF signal to CREB activation. However, inhibition of both the ERK/RSK and the p38/MAPKAP kinase 2 pathways completely abolished NGF-induced CREB Ser-133 phosphorylation. These findings indicate that NGF activates two distinct MAPK pathways, both of which contribute to the phosphorylation of the transcription factor CREB and the activation of immediate-early genes.


Blood ◽  
2007 ◽  
Vol 110 (5) ◽  
pp. 1420-1428 ◽  
Author(s):  
Chia-Lin Hsu ◽  
Kazu Kikuchi ◽  
Motonari Kondo

Abstract Common lymphoid progenitors (CLPs) are lymphoid-lineage-committed progenitor cells. However, they maintain a latent myeloid differentiation potential that can be initiated by stimulation with interleukin-2 (IL-2) via ectopically expressed IL-2 receptors. Although CLPs express IL-7 receptors, which share the common γ chain with IL-2 receptors, IL-7 cannot initiate lineage conversion in CLPs. In this study, we demonstrate that the critical signals for initiating lineage conversion in CLPs are delivered via IL-2 receptor β (IL-2Rβ) intracellular domains. Fusion of the A region of the IL-2Rβ cytoplasmic tail to IL-7Rα enables IL-7 to initiate myeloid differentiation in CLPs. We found that Shc, which associates with the A region, mediates lineage conversion signals through the mitogen activated protein kinase (MAPK) pathway. Because mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) inhibitors completely blocked IL-2-mediated lineage conversion, MAPK activation, specifically via the MEK/ERK pathway, is critically involved in the initiation of this event. Furthermore, formation of granulocyte/macrophage (GM) colonies by hematopoietic stem cells, but not by common myeloid progenitors (CMPs), was severely reduced in the presence of MEK/ERK inhibitors. These results demonstrate that activation of MEK/ERK plays an important role in GM lineage commitment.


Sign in / Sign up

Export Citation Format

Share Document