Ethanol beverages containing polyphenols decrease nuclear factor kappa-B activation in mononuclear cells and circulating MCP-1 concentrations in healthy volunteers during a fat-enriched diet.

AIMS: Different epidemiological studies have demonstrated that some ethanol containing beverages intake could be associated with a reduction of cardiovascular mortality, effect attributed in part to its antioxidant properties. Nuclear factor-kappa B (NF-kappaB) is a redox sensitive transcription factor implicated in the pathogenesis of atherosclerosis. We have examined the effect of four different ethanol containing beverages on the activation of NF-kappaB in peripheral blood mononuclear cells (PBMC) and circulating concentrations of monocyte chemoattractant protein-1 (MCP-1) in healthy volunteers receiving a fat-enriched diet. METHODS AND RESULTS: Sixteen volunteers received 16 g/m(2) of ethanol in form of red wine, spirits (vodka, rum, and brandy) or no ethanol intake along with a fat-enriched diet during 5 days and all of them took all alcohols at different periods. NF-kappaB activation (electrophoretic mobility shift assay) and circulating MCP-1 levels (ELISA) were examined in blood samples taken before and after 5 days of ethanol intake. Subjects receiving a fat-enriched diet had increased NF-kappaB activation in PBMC at day 5. Furthermore, MCP-1 levels were increased in plasma at day 5. Red wine intake and some ethanol beverages containing polyphenols (brandy and rum) prevented NF-kappaB activation and decreased MCP-1 release. CONCLUSION: Consumption of moderate amounts of alcoholic drinks containing polyphenols decreases NF-kappaB activation in PBMCs and MCP-1 plasma levels during a fat-enriched diet. Our results provide additional evidence of the anti-inflammatory effects of some ethanol containing beverages, further supporting the idea that its moderate consumption may help to reduce overall cardiovascular mortality.

Inhibition of brush border dipeptidase with cilastatin reduces toxic accumulation of cyclosporin A in kidney proximal tubule epithelial cells.

BACKGROUND: Cilastatin reduces nephrotoxicity associated with cyclosporin A (CyA) in solid organ and bone marrow transplantation. This appears to be unrelated to changes in renal haemodynamics or CyA metabolism. How cilastatin induces this protection is unclear, but it could result from changes on accumulation of CyA proximal cells. METHODS: We investigated the effects of cilastatin on primary cultures of pig kidney proximal tubule epithelial cells (PTECs) treated with CyA and FK506. Cell membrane fluidity and membrane-bound cholesterol-rich raft (MBCR) distribution were evaluated by fluorescence microscopy, and CyA transport by radioimmunoassay. Changes in CyA- and FK506-induced apoptosis were also evaluated by electron and light microscopy, flow cytometry, and detection of cytoplasmic nucleosones by enzyme-linked immuosorbent assay. RESULTS: CyA caused a dose-dependent reduction of cell membrane fluidity, which was prevented by pre-treating PTECs with cilastatin. Cilastatin also inhibited CyA transport across membranes and reduced recovery of CyA in mitochondria and membrane-bound fractions from cilastatin-treated PTECs. This effect was not related to an altered distribution of MBCRs, which are essential for CyA transport. Cilastatin protected against CyA- and FK506-induced apoptosis. CONCLUSIONS: Prevention of CyA-induced reduction of cell membrane fluidity and inhibition of CyA transport are features of cilastatin's direct effects on PTECs. Unaltered distribution of MBCRs in the presence of cilastatin suggests that cilastatin binding to raft-bound dipeptidases, rather than MBCR modifications, causes interference with CyA transport. These results provide additional insight into the mechanisms and scope of cilastatin nephroprotection.

Potentiation by nitric oxide of cyclosporin A and FK506-induced apoptosis in renal proximal tubule cells.

Proximal tubular epithelial cells (PTEC) exhibit a high sensitivity to undergo apoptosis in response to proinflammatory stimuli and immunosuppressors and participate in the onset of several renal diseases. This study examined the expression of inducible nitric oxide (NO) synthase after challenge of PTEC with bacterial cell wall molecules and inflammatory cytokines and analyzed the pathways that lead to apoptosis in these cells by measuring changes in the mitochondrial transmembrane potential and caspase activation. The data show that the apoptotic effects of proinflammatory stimuli mainly were due to the expression of inducible NO synthase. Cyclosporin A and FK506 inhibited partially NO synthesis. However, both NO and immunosuppressors induced apoptosis, probably through a common mechanism that involved the irreversible opening of the mitochondrial permeability transition pore. Activation of caspases 3 and 7 was observed in cells treated with high doses of NO and with moderate concentrations of immunosuppressors. The conclusion is that the cooperation between NO and immunosuppressors that induce apoptosis in PTEC might contribute to the renal toxicity observed in the course of immunosuppressive therapy.