Browsing Department of Animal Biology by Subject "15(S)-HETE"
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Item15(S)-HETE-induced angiogenesis in adipose tissue is mediated through activation of PI3K/Akt/mTOR signaling pathway( 2013-12-01) Soumya, Sasikumar J. ; Binu, Sheela ; Helen, Antony ; Reddanna, Pallu ; Sudhakaran, Perumana R.Chronic low-grade inflammation underlies obesity and associated metabolic dysfunctions. Lipoxygenase pathways are activated in adipose tissue during obese conditions. Since adipogenesis is associated with angiogenesis, the present study was designed to examine the role of 15-lipoxygenase metabolite, 15(S)-hydroxyeicosatetraenoic acid [15(S)-HETE] on angiogenesis in adipose tissue. Results showed that 15(S)-HETE induced sprouting in fat pad stromovascular tissues, induced morphological changes relevant to angiogenesis in endothelial cells derived from adipose tissue, upregulated the production of CD31, upregulated the gene level expression and production of vascular endothelial growth factor (VEGF), indicating the pro-angiogenic effect of 15(S)-HETE. LY294002, an inhibitor of PI3K-Akt pathway, and rapamycin, inhibitor of mammalian target of rapamycin (mTOR), significantly reversed the effect of 15(S)-HETE. 15(S)-HETE also induced activation of Akt and mTOR. These observations suggest that 15(S)-HETE stimulates angiogenesis in adipose tissue through activation of PI3K/Akt/mTOR signaling. © 2013 Published by NRC Research Press.
ItemEffect of 15-lipoxygenase metabolites on angiogenesis: 15(S)-HPETE is angiostatic and 15(S)-HETE is angiogenic( 2012-07-01) Soumya, Sasikumar J. ; Binu, Sheela ; Helen, A. ; Anil Kumar, K. ; Reddanna, P. ; Sudhakaran, Perumana R.Objective: 15(S)-Hydroxyeicosatetraenoic acid [15(S)-HETE] and 15(S)-hydroperoxyeicosatetraenoic acid [15(S)-HPETE] are the products of arachidonic acid formed in the 15-lipoxygenase pathway. They have opposing effects on the inflammatory process. The present study was designed to examine the role of these metabolites on angiogenesis, which is critically associated with inflammatory conditions. Methods: Chick chorio-allantoic membrane (CAM), rat aortic rings and human umbilical vein endothelial cells (HUVECs) in culture were used to study the effect of 15(S)-HETE and 15(S)-HPETE on angiogenesis. Biochemical markers of angiogenesis were analysed by ELISA. Results: 15(S)-HETE increased vessel density in chick CAM, induced sprouting in rat aortic rings and increased endothelial cell-cell contact and formation of tubular network-like structures in HUVECs. Furthermore, it up-regulated the expression of CD31, E-selectin and vascular endothelial growth factor (VEGF) in HUVECs, indicating its pro-angiogenic effect. 15(S)-HPETE, on the other hand, decreased vessel density in chick CAM, downregulated the expression of E-selectin (<35 %), VEGF (<90 %) and CD31 (<50 %) and did not produce sprouting in aortic rings, suggesting an anti-angiogenic property. 15(S)-HETE-mediated up-regulation of CD 31 and VEGF was reversed by treatment with 15(S)-HPETE. Conclusion; These results indicate the divergent effects of hydroxy and hydroperoxy products of 15-LOX on angiogenesis, highlighting the role of these products in the codependence of inflammation and angiogenesis. © Springer Basel AG 2012.