Gandhi T. K. Boopathy‡§1, Madhura Kulkarni¶, Sze Yuan Ho¶, Adrian Boey‡, Edmond Wei Min Chua‡,
Veluchamy A. Barathi§**‡‡, Tom J. Carney‡§¶, Xiaomeng Wang‡§¶, and Wanjin Hong‡§2
‡Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive,
¶Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
Singapore Eye Research Institute (SERI), 20 College Road, 169856 Singapore
**Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Graduate Medical School, 8 College Rd., 169857 Singapore
‡‡Department of Ophthalmology,
Yong Loo Lin School of Medicine, National University of Singapore, Singapore
§SERI-IMCB Programme in Retinal
Angiogenic Diseases (SIPRAD), SERI-IMCB, Singapore
Published online in The Journal of Biological Chemistry on September 14, 2017
Cavin-2 regulates the activity and stability of endothelial nitric-oxide synthase (eNOS) in angiogenesis
Gandhi T. K. Boopathy, Madhura Kulkarni, Sze Yuan Ho, Adrian Boey, Edmond Wei Min Chua, Veluchamy A. Barathi, Tom J. Carney, Xiaomeng Wang, and Wanjin Hong
J. Biol. Chem. (2017) 292(43) 17760–17776
Angiogenesis is a highly regulated process for formation of
new blood vessels from pre-existing ones. Angiogenesis is dysregulated
in various pathologies, including age-related macular
degeneration, arthritis, and cancer. Inhibiting pathological
angiogenesis therefore represents a promising therapeutic
strategy for treating these disorders, highlighting the need to
study angiogenesis in more detail. To this end, identifying the
genes essential for blood vessel formation and elucidating their
function are crucial for a complete understanding of angiogenesis.
Here, focusing on potential candidate genes for angiogenesis, we
performed a morpholino-based genetic screen in zebrafish and
identified Cavin-2, a membrane-bound phosphatidylserine-binding
protein and critical organizer of caveolae (small microdomains
in the plasma membrane), as a regulator of angiogenesis. Using
endothelial cells, we show that Cavin-2 is required for in vitro
angiogenesis and also for endothelial cell proliferation, migration,
and invasion. We noted a high level of Cavin-2 expression in the
neovascular tufts in the mouse model of oxygen-induced retinopathy,
suggesting a role for Cavin-2 in pathogenic angiogenesis.
Interestingly, we also found that Cavin-2 regulates the production
of nitric oxide (NO) in endothelial cells by controlling the stability
and activity of the endothelial nitric-oxide synthase (eNOS) and
that Cavin-2 knockdown cells produce much less NO than WT
cells. Also, mass spectrometry, flow cytometry, and electron
microscopy analyses indicated that Cavin-2 is secreted in endothelial
microparticles (EMPs) and is required for EMP biogenesis.
Taken together, our results indicate that in addition to its function
in caveolae biogenesis, Cavin-2 plays a critical role in endothelial
cell maintenance and function by regulating eNOS activity.
Figure legend: Scheme of the regulation of nitric oxide (NO) production by Cavin-2 in endothelial cells. The presence of Cavin-2 positively helps in NO production by stabilizing and activating eNOS. The loss of Cavin-2 adversely effects NO production by destabilizing and inactivating eNOS.
For more information on Wanjin HONG's lab, please click here.