Nrf2 regulates angiogenesis: effect on endothelial cells, bone marrow-derived proangiogenic cells and hind limb ischemia.
OBJECTIVE
Nuclear factor E2-related factor 2 (Nrf2), a key cytoprotective transcription factor, regulates also proangiogenic mediators, interleukin-8 and heme oxygenase-1 (HO-1). However, hitherto its role in blood vessel formation was modestly examined. Particularly, although Nrf2 was shown to affect hematopoietic stem cells, it was not tested in bone marrow-derived proangiogenic cells (PACs). Here we investigated angiogenic properties of Nrf2 in PACs, endothelial cells, and inflammation-related revascularization.


RESULTS
Treatment of endothelial cells with angiogenic cytokines increased nuclear localization of Nrf2 and induced expression of HO-1. Nrf2 activation stimulated a tube network formation, while its inhibition decreased angiogenic response of human endothelial cells, the latter effect reversed by overexpression of HO-1. Moreover, lack of Nrf2 attenuated survival, proliferation, migration, and angiogenic potential of murine PACs and affected angiogenic transcriptome in vitro. Additionally, angiogenic capacity of PAC Nrf2(-/-) in in vivo Matrigel assay and PAC mobilization in response to hind limb ischemia of Nrf2(-/-) mice were impaired. Despite that, restoration of blood flow in Nrf2-deficient ischemic muscles was better and accompanied by increased oxidative stress and inflammatory response. Accordingly, the anti-inflammatory agent etodolac tended to diminish blood flow in the Nrf2(-/-) mice.


METHODS
Identification of a novel role of Nrf2 in angiogenic signaling of endothelial cells and PACs.


CONCLUSIONS
Nrf2 contributes to angiogenic potential of both endothelial cells and PACs; however, its deficiency increases muscle blood flow under tissue ischemia. This might suggest a proangiogenic role of inflammation in the absence of Nrf2 in vivo, concomitantly undermining the role of PACs in such conditions.
1 Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University , Krakow, Poland .
Urszula
U
Florczyk
Agnieszka
A
Jazwa
Monika
M
Maleszewska
Mateusz
M
Mendel
Krzysztof
K
Szade
Magdalena
M
Kozakowska
Anna
A
Grochot-Przeczek
Monika
M
Viscardi
Szymon
S
Czauderna
Karolina
K
Bukowska-Strakova
Jerzy
J
Kotlinowski
Alicja
A
Jozkowicz
Agnieszka
A
Loboda
Jozef
J
Dulak
D021581:Active Transport, Cell Nucleus; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001011:Aorta / Q000473:pathology; D001854:Bone Marrow Cells / Q000502:physiology*; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000502:physiology*; D004730:Endothelium, Vascular / Q000473:pathology; D005260:Female; D005263:Femoral Artery / Q000473:pathology; D015870:Gene Expression; D051547:Heme Oxygenase-1 / Q000235:genetics / Q000378:metabolism; D006614:Hindlimb / Q000098:blood supply*; D006801:Humans; D007511:Ischemia / Q000503:physiopathology; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018482:Muscle, Skeletal / Q000378:metabolism; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism*; D018919:Neovascularization, Physiologic; D018384:Oxidative Stress; D013234:Stem Cells / Q000502:physiology; D059467:Transcriptome
D000975:Antioxidants; D008565:Membrane Proteins; D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse; D051547:Heme Oxygenase-1; C496542:Hmox1 protein, mouse