Cyp1B1 expression promotes angiogenesis by suppressing NF-κB activity

Abstract

Nuclear factor-κB (NF-κB) is a master regulator of genes that control a large number of cellular processes, including angiogenesis and inflammation. We recently demonstrated that cytochrome P-450 1B1 (Cyp1B1) deficiency in endothelial cells (EC) and pericytes (PC) results in increased oxidative stress, alterations in migration, attenuation of capillary morphogenesis, sustained activation of NF-κB, and increased expression of thrombospondin-2 (TSP2), an endogenous inhibitor of angiogenesis. On the basis of a growing body of evidence that phenethyl isothiocyanate (PEITC) and pyrrolidine dithiocarbamate (PDTC) function as antioxidants and suppressors of NF-κB activation, we investigated their potential ability to restore a normal phenotype in Cyp1B1-deficient (cyp1b1(-/-)) vascular cells. PEITC and PDTC inhibited NF-κB activity and expression in cyp1b1(-/-) EC and PC. We also observed restoration of migration and capillary morphogenesis of cyp1b1(-/-) EC and decreased cellular oxidative stress in cyp1b1(-/-) EC and PC without restoration to normal TSP2 levels. In addition, expression of a dominant-negative inhibitor κBα, a suppressor of NF-κB activation, decreased NF-κB activity without affecting TSP2 expression in these cells. In contrast, knockdown of TSP2 expression resulted in attenuation of NF-κB activity in cyp1b1(-/-) vascular cells. Furthermore, expression of TSP2 in wild-type (cyp1b1(+/+)) cells resulted in increased NF-κB activity. Together, our results demonstrate an important role for TSP2 in modulation of NF-κB activity and attenuation of angiogenesis. Thus Cyp1B1 expression in vascular cells plays an important role in the regulation of vascular homeostasis through modulation of the cellular reductive state, TSP2 expression, and NF-κB activation.

Thrombospondin-2 Expression During Retinal Vascular Development and Neovascularization

“…We have observed TSP2-GFP expression in retinal vasculature, and predominantly in perivascular supporting cells. 17 The intensity of the green fluorescence increased during the postnatal development of the retinal vascculature in older animals, but it was almost undetectable at later postnatal time (P42). These results were further confirmed by the western blot analysis of GFP protein.…”

“…The generation of a line of TSP2 reporter transgenic mice, where endogenous TSP2 promoter drives expression of green fluorescent protein (GFP), was previously described. 17 The following primers were used for screening of the transgene: GFP forward: 5¢-CCTACGGC GTGCAGT GCTTCAGC-3¢; and GFP reverse: 5¢-CGGCG AGCTGCACGCTGCGTCCTC-3¢.…”

“…Retinal pericytes are the major source of TSP2 in the retinal vasculature or in culture. 12,17 We performed qPCR to detect TSP2 RNA expression in the retina at critical time points of postnatal retinal vascularization. We detected considerable amounts of TSP2 RNA in retina samples from the wild-type mice.…”

Cytochrome P450 Cyp1b1*2 Gene and Its Association With T2d in Tabuk Population, Northwestern Region of Saudi Arabia

“…The major phenotypic features associated with CYP1B1 deletion include protection from the deleterious effects of excess dietary fat, including oxidative stress, hepatic steatosis, and T2D [32]. Recently microarray data from the livers of the CYP1B1 KO mice that are resistant to diet-induced obesity indicated that CYP1B1 deletion substantially alters the expression of genes associated with fatty acid homeostasis [33].…”

The Pharmacology of the Cytochrome P450 Epoxygenase/Soluble Epoxide Hydrolase Axis in the Vasculature and Cardiovascular Disease

“…This effect was linked with a decrease in the expression of eNOS , as well as a corresponding increase in intracellular oxidative stress and increased production of thrombospondin-2, an endogenous inhibitor of angiogenesis (Tang et al, 2009;Palenski et al, 2013). Interestingly, estrogen-induced angiogenesis has also been attributed to changes in eNOS, thrombospondin, and free radical generation, making it tempting to speculate that CYP1B1 may actually mediate the effects of the hormone.…”