Molecular and cellular biochemistry
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Mol. Cell. Biochem. · Jan 2011
Nobiletin, a citrus flavonoid, suppresses invasion and migration involving FAK/PI3K/Akt and small GTPase signals in human gastric adenocarcinoma AGS cells.
Nobiletin, a compound isolated from citrus fruits, is a polymethoxylated flavone derivative shown to have anti-inflammatory, antitumor, and neuroprotective properties. This study has investigated that nobiletin exerted inhibitory effects on the cell adhesion, invasion, and migration abilities of a highly metastatic AGS cells under non-cytotoxic concentrations. Data also showed nobiletin could inhibit the activation of focal adhesion kinase (FAK) and phosphoinositide-3-kinase/Akt (PI3K/Akt) involved in the downregulation of the enzyme activities, protein expressions, messenger RNA levels of matrix metalloproteinase-2 (MMP-2), and matrix metalloproteinase-2 (MMP-9). ⋯ Otherwise, nobiletin-treated AGS cells showed tremendously decreased in the phosphorylation and degradation of inhibitor of kappaBα (IκBα), the nuclear level of NF-κB, and the binding ability of NF-κB to NF-κB response element. Furthermore, nobiletin significantly decreased the levels of phospho-Akt and MMP-2/9 in Akt1-cDNA-transfected cells concomitantly with a marked reduction in cell invasion and migration. These results suggest that nobiletin can reduce invasion and migration of AGS cells, and such a characteristic may be of great value in the development of a potential cancer therapy.
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Mol. Cell. Biochem. · Jan 2011
Cardioprotection by ischemic postconditioning is abolished in depressed rats: role of Akt and signal transducer and activator of transcription-3.
Ischemic postconditioning (IPC) represents one of the most effective cardioprotective strategies against myocardial ischemia/reperfusion. Depression is commonly present in patients with coronary heart disease. However, whether depression interferes with the cardioprotection of IPC during myocardial ischemia/reperfusion and their underlying mechanisms remain largely unknown. ⋯ However, these cardioprotective effects of IPC were not observed in depressed rats. In addition, IPC had no effects on the phosphorylation of AKT and STAT-3 at reperfusion in depressed hearts, although it markedly increased the phosphorylation of AKT and STAT-3 at reperfusion in non-depressed hearts. In conclusion, these data indicate that cardioprotection by IPC is abolished during myocardial ischemia/reperfusion in depressed rats, and the underlying mechanisms are probably related to the impaired activation of AKT and STAT-3 at reperfusion.
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Mol. Cell. Biochem. · Dec 2010
Anti-hyperlipidemic and insulin sensitizing activities of fenofibrate reduces aortic lipid deposition in hyperlipidemic Golden Syrian hamster.
Cholesterol ester transfer protein (CETP) and apolipoprotein (apo) E are important in peroxisome proliferation activated receptor-α (PPAR-α)-mediated regulation of lipoprotein metabolism. Therefore, popularly used apolipoprotein E knockout mice are not suitable to evaluate PPAR-α agonists. In this study, we aimed to: a) evaluate hamster as a model for insulin resistance, hyperlipidemia and atherosclerosis; and b) investigate the effect of a PPAR-α activator, fenofibrate, in this model. ⋯ Our results showed that fenofibrate treatment reduced aortic lipid deposition by 70%. These findings suggest that hamster may be an adequate animal model to evaluate the efficacy of lipid lowering, insulin sensitizing and antiatherosclerotic agents. We also show that fenofibrate is an effective antiatherosclerotic agent in hyperlipidemic hamster model.
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Mol. Cell. Biochem. · Jun 2010
Propofol protects against hydrogen peroxide-induced oxidative stress and cell dysfunction in human umbilical vein endothelial cells.
Propofol has been reported to protect vascular endothelial cells against oxidative stress and dysfunction, but the underlying mechanisms are not clear. In this study, we studied hydrogen peroxide (H(2)O(2))-induced oxidative stress and cell dysfunction in human umbilical vein endothelial cells (HUVECs) and especially, their modulation by propofol. HUVECs were treated with different concentrations (0.1 and 0.5 mM) of H(2)O(2) for different times (1, 3, and 6 h). ⋯ Further, we measured monocyte adhesion as a marker of endothelial cell dysfunction. H(2)O(2) increased the adhesion of monocytes to HUVECs, and propofol pretreatment reduced the adhesion in a fashion similar to SB203580. We concluded that propofol, by inhibiting p38 MAPK and NF-kappaB activity, decreasing NOS expression, reducing NO production, could protect HUVECs which are exposed to oxidative stress and becoming dysfunctional.
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Mol. Cell. Biochem. · Jun 2010
Time-dependent alterations of cerebral proteins following short-term normobaric hyperoxia.
Sufficient oxygenation is indispensable for cognitive performance in mammals. In order to assure adequate oxygenation and to prevent hypoxia in medicine or aviation, different approaches of oxygen delivery are realized. With regard to hyperoxia, it is well known that it increases the risk of tissue toxicity and inflammation by generating radical oxygen species. ⋯ IPA generated a network with eight focus proteins associated with pathways in "cell death, cancer, and signalling". Although hyperoxia was normobaric and induced for only 3 h, significant changes in brain protein expression were detectable immediately after the 3 h, after 3 days, as well as after 7 days. This may indicate effects on brain protein expression take place in the rat brain following a relatively short period of hyperoxia.