ERK1/2-Akt1 crosstalk regulates arteriogenesis in mice and zebrafish
Bin Ren, … , Randall T. Peterson, Michael Simons
Bin Ren, … , Randall T. Peterson, Michael Simons
Published March 8, 2010
Citation Information: J Clin Invest. 2010;120(4):1217-1228. https://doi.org/10.1172/JCI39837.
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Research Article Vascular biology

ERK1/2-Akt1 crosstalk regulates arteriogenesis in mice and zebrafish

Abstract

Arterial morphogenesis is an important and poorly understood process. In particular, the signaling events controlling arterial formation have not been established. We evaluated whether alterations in the balance between ERK1/2 and PI3K signaling pathways could stimulate arterial formation in the setting of defective arterial morphogenesis in mice and zebrafish. Increased ERK1/2 activity in mouse ECs with reduced VEGF responsiveness was achieved in vitro and in vivo by downregulating PI3K activity, suppressing Akt1 but not Akt2 expression, or introducing a constitutively active ERK1/2 construct. Such restoration of ERK1/2 activation was sufficient to restore impaired arterial development and branching morphogenesis in synectin-deficient mice and synectin-knockdown zebrafish. The same approach effectively stimulated arterial growth in adult mice, restoring arteriogenesis in mice lacking synectin and in atherosclerotic mice lacking both LDL-R and ApoB48. We therefore conclude that PI3K-ERK1/2 crosstalk plays a key role in the regulation of arterial growth and that the augmentation of ERK signaling via suppression of the PI3K signaling pathway can effectively stimulate arteriogenesis.

Authors

Bin Ren, Yong Deng, Arpita Mukhopadhyay, Anthony A. Lanahan, Zhen W. Zhuang, Karen L. Moodie, Mary Jo Mulligan-Kehoe, Tatiana V. Byzova, Randall T. Peterson, Michael Simons

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Figure 5

Restoration of ERK1/2 activation in vivo improves angiogenesis.

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Restoration of ERK1/2 activation in vivo improves angiogenesis. (A) DIVA...
(A) DIVAA tubes containing vehicle control or 100 ng/ml VEGF-A with heparin were placed into synectin-null (n = 8) or WT (n = 8) mice. Note restoration of neovascularization in GS4898-treated synectin-null mice in the presence of VEGF 14 days later. (B) In vivo Matrigel plug assay. Control plugs containing no virus or VEGF, or plugs containing VEGF and either Ad-ME or Ad-ME-LA virus, were implanted into synectin-null mice (n = 8). Matrigel plugs containing VEGF were implanted into WT mice as controls (n = 8). Note extensive neovascularization in VEGF plus Ad-ME-LA plugs in synectin-null mice. (C and D) VEGF-induced VEGFR2 phosphorylation in Ldlr–/– ApoB48-modified mice. Ldlr–/– ApoB48-modified mice maintained for 11 weeks on either chow (n = 6) or high-fat diet (n = 6) were injected intraperitoneally with VEGF-A (50 ng/ml), and the extent of VEGFR2 phosphorylation (anti-Y1175 Ab) (C) and ERK1/2 phosphorylation (D) was assessed by Western blotting of heart (H), liver (L), and skeletal muscle (M) tissue samples. Note decreased activation of both VEGFR2 Y1175 and ERK1/2 in Ldlr–/– ApoB48-modified mice fed high-fat diet. (E and F) Adventitial angiogenesis assay. Ad-null control (n = 6) or Ad-ME-LA (n = 6) viruses in pluronic gel were added to the adventitial surface of aortas of Ldlr–/– ApoB48-modified mice fed a high-fat diet. Note the marked increase in neovascularization of aortas treated with Ad-ME-LA virus 21 days later. Scale bars: 10 μm. *P < 0.05 vs. control.