ABSTRACT
BACKGROUND: 15d-PGJ2 has been known to act as an anti-inflammatory agent and has anti-hypertensive effects. As a result of these properties, we examined the effect of 15d-PGJ2 on the LPS-induced IL-8/CXCL8 mRNA expression in VSMCs from SHR. METHODS: Effect and action mechanism of 15d-PGJ2 on the expression of LPS-induced IL-8/CXCL8 mRNA in VSMCs from SHR and WKY were examined by using real-time polymerase chain reaction, electrophoretic mobility shift assay for NF-kappaB avtivity, Western blotting analysis for ERK and p38 phosphorylation and flow cytometry for NAD(P)H oxidase activity. RESULTS: 15d-PGJ2 decreased the expression of LPS-induced IL-8/CXCL8 mRNA in WKY VSMCs, but increased the expression of LPS-induced IL-8/CXCL8 mRNA in SHR VSMCs. The upregulatory effect of 15d-PGJ2 in SHR VSMCs was mediated through PPAR gamma, and dependent on NF-kappaB activation and ERK phosphorylation. However, inhibition of the p38 signaling pathway augmented the upregulatory effect of 15d-PGJ2 on LPS-induced IL-8/CXCL8 mRNA. A NAD(P)H oxidase inhibitor inhibited the upregulatory effect of 15d-PGJ2 on LPS-induced IL-8/CXCL8 mRNA expression in SHR VSMCs, and an increase in NAD(P)H oxidase activity was detected in SHR VSMCs treated with 15d-PGJ2/LPS. CONCLUSION: Our results indicate that the upregulatory effect of 15d-PGJ2 on LPS-induced IL-8/CXCL8 expression in SHR VSMCs is mediated through the PPAR gamma and ERK pathway, and may be related to NAD(P)H oxidase activity. However, p38 inactivation may also play an important role in 15d-PGJ2/LPS-induced IL-8/CXCL8 expression in SHR VSMCs.
Subject(s)
Blotting, Western , Electrophoretic Mobility Shift Assay , Flow Cytometry , MAP Kinase Signaling System , Muscle, Smooth, Vascular , NADPH Oxidases , NF-kappa B , Phosphorylation , PPAR gamma , Prostaglandin D2 , Rats, Inbred SHR , Real-Time Polymerase Chain Reaction , RNA, MessengerABSTRACT
Angiotensin II (Ang II) plays an important role in vascular hypertension. The role of the chemokine CCL5 on Ang II-induced activities in vascular smooth muscle cells (VSMCs) has not been studied. In this study, we elucidated the effect of CCL5 on Ang II-induced 12-lipoxygenase (LO) expression and cell proliferation in spontaneously hypertensive rats (SHR) VSMCs. CCL5 decreased Ang II-induced 12-LO mRNA expression and protein production, and it increased Ang II type 2 (AT2) receptor expression in SHR VSMCs. The inhibitory effect of CCL5 on Ang II-induced 12-LO mRNA expression was mediated through the AT2 receptor. Although treatment of CCL5 alone induced SHR VSMCs proliferation, CCL5 inhibited Ang II-induced VSMCs proliferation and PD123,319, an AT2 receptor antagonist, blocked the inhibitory effect of CCL5 on Ang II-induced VSMCs proliferation. Phosphorylation of p38 was detected in VSMCs treated with Ang II or CCL5 alone. But, decrease of p38 phosphorylation was detected in VSMCs treated with Ang II and CCL5 simultaneously (Ang II/CCL5) and PD123,319 increased p38 phosphorylation in VSMCs treated with Ang II/CCL5. Therefore, these results suggest that the inhibitory effect of CCL5 on Ang II-induced VSMCs proliferation is mediated by the AT2 receptor via p38 inactivation, and CCL5 may play a beneficial role in Ang II-induced vascular hypertension.
Subject(s)
Angiotensin II , Angiotensins , Arachidonate 12-Lipoxygenase , Cell Proliferation , Chemokine CCL5 , Down-Regulation , Hypertension , Muscle, Smooth, Vascular , Phosphorylation , Rats, Inbred SHR , Receptor, Angiotensin, Type 2 , RNA, MessengerABSTRACT
BACKGROUND: We previously demonstrated remarkable differences in the expression of IL-8/CXCL8 in aortic tissues and vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) compared to VSMC from normotensive Wistar-Kyoto rats (WKY). In the present study, we investigated the direct effect of IL-8/CXCL8 on expression of 12-lipoxygenase (LO), a hypertensive modulator, in SHR VSMC. METHODS: Cultured aortic VSMC from SHR and WKY were used. Expression of 12-LO mRNA was determined by real-time polymerase chain reaction. Phosphorlyation of ERK1/2 and production of 12-LO and angiotensin II subtype 1 (AT1) receptor were assessed by Western blots. IL-8/CXCL8-stimulated DNA synthesis was determined by measuring incorporation of [3H]-thymidine. And effect of IL-8/CXCL8 on vascular tone was determined by phenylephrine-induced contraction of thoracic aortic rings. RESULTS: Treatment with IL-8/CXCL8 greatly increased 12-LO mRNA expression and protein production compared to treatment with angiotensin II. IL-8/CXCL8 also increased the expression of the AT1 receptor. The increase in 12-LO induced by IL-8/CXCL8 was inhibited by treatment with an AT1 receptor antagonist. The induction of 12-LO mRNA production and the proliferation of SHR VSMC by IL-8/CXCL8 was mediated by the ERK pathway. The proliferation of SHR VSMC and the vascular contraction in the thoracic aortic ring, both of which were induced by IL-8/CXCL8, were inhibited by baicalein, a 12-LO inhibitor. CONCLUSION: These results suggest that the potential role of IL-8/CXCL8 in hypertensive processes is likely mediated through the 12-LO pathway.
Subject(s)
Animals , Rats , Angiotensin II , Arachidonate 12-Lipoxygenase , Blotting, Western , Contracts , DNA , Flavanones , MAP Kinase Signaling System , Muscle, Smooth, Vascular , Rats, Inbred SHR , Real-Time Polymerase Chain Reaction , RNA, MessengerABSTRACT
Endothelin-1 (ET-1) has been characterized as a potent vasoconstrictor secreted by the endothelium, and play a major role in the regulation of vascular tone. It has been also known to participate in inflammatory reactions. The production of ET-1 by macrophages during infection and inflammation is related to tissue perfusion and leukocyte extravasation. The aim of this study is to investigate the role of IL-8/CXCL8, as a major inflammatory chemokine, for ET-1 expression in macrophges. Expression of ET-1 mRNA in mouse peritoneal macrophages (PeM phi) was weaker than that in vascular smooth muscle cells (VSMCs) from spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). However, expression of IL-8/CXCL8-induced ET-1 mRNA in PeM phi was much more stronger than that in SHR and WKY VSMCs. Maximum expression of ET-1 mRNA was observed at 50 ng/ml dose of IL-8/CXCL8 and occurred at 2 h after addition of IL-8/CXCL8. Expression of ET-1 by IL-8/CXCL8 was dependent on NF-kappaB activation and ERK1/2 phosphorylation. Baicalein, a 12-lipoxygenase (LO) inhibitor, inhibited the expression of IL-8/CXCL8-induced ET-1 mRNA. This inhibitory action of baicalein was mediated via ERK1/2 inactivation. Induction of 12-LO mRNA by IL-8/CXCL8 and expression of ET-1 mRNA by 12-LO metabolite, 12(S)-HETE were also detected. The expression of IL-8/CXCL8-induced ET-1 mRNA was not detected in PeM phi transfected with 12-LO siRNA. These results suggest that IL-8/CXCL8 can act as one of main inducers of ET-1 in vascular inflammatory reactions, and ET-1 expression by IL-8/CXCL8 is related to 12-LO pathway in PeM phi.
Subject(s)
Animals , Mice , Rats , Arachidonate 12-Lipoxygenase , Endothelin-1 , Endothelium , Flavanones , Inflammation , Leukocytes , Macrophages , Macrophages, Peritoneal , Muscle, Smooth, Vascular , NF-kappa B , Perfusion , Phosphorylation , Rats, Inbred SHR , RNA, Messenger , RNA, Small InterferingABSTRACT
Septooptic dysplasia is a rare anterior midline anomaly considered to be a mild form of lobar holoprosencephaly. We describe a case with unilateral optic nerve hypoplasia and the absence of a septum pellucidum.