Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology
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Cell. Physiol. Biochem. · Jan 2009
Epigallocatechin-3-O-gallate decreases tumor necrosis factor-alpha-induced fractalkine expression in endothelial cells by suppressing NF-kappaB.
Epigallocatechin-3-O-gallate (EGCG), the main catechin in green tea, has anti-oxidant, anti-atherosclerotic and anti-inflammatory properties. Fractalkine, a chemokine involved in inflammation and early atherosclerotic processes, acts as a chemoattractant as well as an adhesion molecule in endothelial cells activated by proinflammatory cytokines. In the present study, we investigated the effect of EGCG on fractalkine expression in TNF-alpha-induced human umbilical vein endothelial cells (HUVECs). ⋯ Furthermore, EGCG inhibited monocyte adhesion to HUVECs stimulated by TNF-alpha. The silencing of fractalkine with an siRNA or treatment with a blocking antibody against fractalkine suppressed the TNF-alpha-induced increase in monocyte adhesion. These results demonstrate that EGCG prevents TNF-alpha-induced vascular endothelial fractalkine expression.
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Cell. Physiol. Biochem. · Jan 2009
Angiotensin II induces inflammatory response partly via toll-like receptor 4-dependent signaling pathway in vascular smooth muscle cells.
Angiotensin (Ang II) plays an important role in atherosclerosis through proinflammatory effect. Toll-like receptor 4 (TLR4) may mediate inflammatory response. It is unknown whether TLR4 mediates the proinflammatory effect of Ang II. ⋯ The further investigations showed that AT1 receptor antagonist losartan or ERK1/2 inhibitor PD098059 inhibited Ang II-induced TLR4 expression, TLR4 inhibitor prevented Ang II- induced IP-10 expression, anti-IP-10 antibody partly abolished Ang II- induced PKC increase, and PKC inhibitor chelerythrine suppressed Ang II- induced NF-kappaB expression. These demonstrate that TLR4-mediated proinflammatory effect of Ang II in VSMCs involves AT1/ERK1/2/TLR4/IP-10/ PKC/NF-kappaB pathway. Our results provide the evidence that Ang II induces inflammatory response involved in pathogenesis of atherosclerosis partly via TLR4- dependent signaling pathway in VSMCs.
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Cell. Physiol. Biochem. · Jan 2007
Epigallocatechin-3-O-gallate inhibits the angiotensin II-induced adhesion molecule expression in human umbilical vein endothelial cell via inhibition of MAPK pathways.
Epigallocatechin-3-O-gallate (EGCG) is the main catechin, which is derived from Camellia sinensis plant. Vascular cell adhesion molecules (VCAMs) and intercellular adhesion molecules (ICAMs) mediate the binding of inflammatory cells onto the vascular wall-promoting the early phase of atherosclerosis. In the present study, we investigated the mechanism(s) by which EGCG inhibits angiotensin II (Ang II)-induced elevation of the membrane associated VCAM-1 and ICAM-1 in human umbilical vein endothelial cells (HUVEC). ⋯ PD98059, an inhibitor of ERK1/2 inhibited the Ang II-induced increase of VCAM-1 but not of ICAM-1 in the plasma membranes. In contrast, SB203580, an inhibitor of p38 MAPK inhibited both the Ang II-induced enrichment of ICAM-1 and VCAM-1. From these results, it may be concluded that EGCG inhibits the Ang II-induced elevation of VCAM-1 and ICAM-1 in the HUVEC plasma membranes via inhibition of the p38 MAPK and the ERK1/2 signalling pathways resulting in an inhibition of the VCAM-1 and ICAM-1 transcription.
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Cell. Physiol. Biochem. · Jan 2007
A single binding motif is required for SPAK activation of the Na-K-2Cl cotransporter.
SPAK (Ste20p-related proline alanine-rich kinase) phosphorylates and activates NKCC1 (Na-K-2Cl cotransporter) in the presence of another serine/threonine kinase WNK4 (With No lysine (K)). However, whether or not the docking of SPAK to NKCC1 is a requirement for cotransporter activation has not been fully resolved. ⋯ We demonstrate that physical docking of SPAK to NKCC1 is necessary for cotransporter activity under both baseline and hyperosmotic conditions. We identify T(206) and T(211) as major phospho-acceptor sites involved in cotransporter function, with T(206) common to two separate regulatory pathways: one involving SPAK, the other involving a still unknown kinase that is responsive to forskolin/PKA stimulation.
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Cell. Physiol. Biochem. · Jan 2004
Arrhythmia in isolated prenatal hearts after ablation of the Cav2.3 (alpha1E) subunit of voltage-gated Ca2+ channels.
A voltage-gated calcium channel containing Cav2.3e (alpha1Ee) as the ion conducting pore has recently been detected in rat heart. Functional evidence for this Ca2+ channel to be involved in the regulation of heart beating, besides L- and T-type channels, was derived from murine embryos where the gene for Cav1.2 had been ablated. The remaining "L-type like" current component was not related to recombinant splice variants of Cav1.3 containing channels. ⋯ The spontaneous activity of murine embryonic hearts was recorded by using a multielectrode array. Between day 9.5 p.c. to 12.5 p.c., the beating frequency of isolated embryonic hearts from Cav2.3-deficient mice did not differ significantly from control mice but the coefficient of variation within individual episodes was more than four-fold increased in Cav2.3-deficient mice indicating arrhythmia. In isolated hearts from wild type mice, arrhythmia was induced by superfusion with a solution containing 200 nM SNX-482, a blocker of some R-type voltage gated Ca2+ channels, suggesting that R-type channels containing the splice variant Cav2.3e as ion conducting pore stabilize a more regular heart beat in prenatal mice.