α-Melanocyte-stimulating hormone inhibits angiogenesis through attenuation of VEGF/VEGFR2 signaling pathway

Wen-Tsan Weng; Shih-Chung Huang; Yi-Ling Ma; Hoi-Hung Chan; Shih-Wei Lin; Jian-Ching Wu; Chang-Yi Wu; Zhi-Hong Wen; E-Ming Wang; Chao-Liang Wu; Ming-Hong Tai

doi:10.1016/j.bbagen.2014.02.005

α-Melanocyte-stimulating hormone inhibits angiogenesis through attenuation of VEGF/VEGFR2 signaling pathway

Biochim Biophys Acta. 2014 Jun;1840(6):1850-60. doi: 10.1016/j.bbagen.2014.02.005. Epub 2014 Feb 14.

Authors

Wen-Tsan Weng¹, Shih-Chung Huang², Yi-Ling Ma³, Hoi-Hung Chan⁴, Shih-Wei Lin⁵, Jian-Ching Wu⁶, Chang-Yi Wu⁷, Zhi-Hong Wen⁸, E-Ming Wang⁹, Chao-Liang Wu¹⁰, Ming-Hong Tai¹¹

Affiliations

¹ Institute of Basic Medical Sciences, National Cheng Kung University, Tainan 701, Taiwan. Electronic address: bppig@yahoo.com.tw.
² Department of Internal Medicine, Kaohsiung Armed Forces General Hospital, Kaohsiung 802, Taiwan; Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung 804, Taiwan. Electronic address: Sghung@hotmail.com.
³ Division of Nephrology, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan; Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung 804, Taiwan. Electronic address: ylma@vghks.gov.tw.
⁴ Division of Gastroenterology, Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan. Electronic address: hoihungchan@gmail.com.
⁵ Institute of Marine Biotechnology, National Sun Yat-Sen University, Kaohsiung 804, Taiwan. Electronic address: Shiwey@yahoo.com.tw.
⁶ Institute of Marine Biotechnology, National Sun Yat-Sen University, Kaohsiung 804, Taiwan. Electronic address: djbluestyle338@hotmail.com.
⁷ Division of Nephrology, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan. Electronic address: cywu@mail.nsysu.edu.tw.
⁸ Institute of Marine Biotechnology and Resources, Asia-Pacific Ocean Research Center, National Sun Yat-Sen University, Kaohsiung 804, Taiwan. Electronic address: wzh@mail.nsysu.edu.tw.
⁹ Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung 804, Taiwan. Electronic address: emwang@vghks.gov.tw.
¹⁰ Institute of Basic Medical Sciences, National Cheng Kung University, Tainan 701, Taiwan; Department of Biochemistry and Molecular Biology, National Cheng Kung University Medical College, Tainan 701, Taiwan. Electronic address: wumolbio@mail.ncku.edu.tw.
¹¹ Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung 804, Taiwan; Institute of Marine Biotechnology, National Sun Yat-Sen University, Kaohsiung 804, Taiwan; Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan. Electronic address: minghongtai@gmail.com.

PMID: 24530634
DOI: 10.1016/j.bbagen.2014.02.005

Abstract

Background: Gene therapy of proopiomelanocortin, the precursor of α-melanocyte-stimulating hormone (α-MSH), suppresses the neovascularization in tumors. However, the roles of α-MSH in angiogenesis remain unclear.

Methods: The influence of α-MSH on angiogenesis was evaluated by ex vivo rat aorta and in vivo, including transgenic zebrafish and chicken chorioallantoic membrane (CAM) assays. The effect of α-MSH on proliferation, matrix metalloproteinase (MMP) secretion, migration and tube formation was examined using human umbilical vein endothelial cells (HUVECs). The expression of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2) was investigated by quantitative RT-PCR, immunoblot and immunofluorescent analysis. Antibodies' neutralization was employed to dissect the receptor(s) transmitting α-MSH signaling.

Results: Application of α-MSH potently suppressed the microvessels sprouting in organotypic aortic rings. Besides, α-MSH perturbed the vessels development in zebrafish and chicken embryos. α-MSH (0.01-10nM) inhibited the MMP-2 secretion, migration and tube formation of HUVECs without affecting proliferation. Mechanistic studies unveiled α-MSH decreased the VEGF expression and release in HUVECs. Besides, α-MSH downregulated the VEGFR2 expression at transcriptional and translational levels. Importantly, α-MSH attenuated the Akt phosphorylation, but enhanced the expression of PTEN, endogenous antagonist of PI3K/Akt signaling. Expression analysis and antibody neutralization revealed that MC1-R and MC2-R participated in α-MSH-induced blockage of migration and VEGF/VEGFR2/Akt signaling. However, VEGF supply failed to reverse the anti-angiogenic function of α-MSH.

Conclusions: α-MSH inhibits the physiological angiogenesis by attenuating VEGF/VEGFR2/Akt signaling in endothelial cells.

General significance: α-MSH is a potent angiogenesis inhibitor targeting at endothelial VEGF/VEGFR2 signaling, which may have potential for therapeutic application.

Keywords: Angiogenesis; HUVEC; Proopiomelanocortin; VEGF; α-MSH.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Angiogenesis Inhibitors / pharmacology*
Animals
Cells, Cultured
Humans
Male
Neovascularization, Physiologic / drug effects
PTEN Phosphohydrolase / analysis
Phosphorylation
Proto-Oncogene Proteins c-akt / metabolism
Rats
Rats, Sprague-Dawley
Receptor, Melanocortin, Type 1 / physiology
Receptor, Melanocortin, Type 2 / physiology
Signal Transduction / drug effects*
Vascular Endothelial Growth Factor A / antagonists & inhibitors
Vascular Endothelial Growth Factor A / physiology*
Vascular Endothelial Growth Factor Receptor-2 / antagonists & inhibitors
Vascular Endothelial Growth Factor Receptor-2 / physiology*
Zebrafish
alpha-MSH / pharmacology*

Substances

Angiogenesis Inhibitors
Receptor, Melanocortin, Type 1
Receptor, Melanocortin, Type 2
Vascular Endothelial Growth Factor A
alpha-MSH
Vascular Endothelial Growth Factor Receptor-2
Proto-Oncogene Proteins c-akt
PTEN Phosphohydrolase
Pten protein, rat