Unconjugated bile acids modulate adult and neonatal neutrophil chemotaxis induced in vitro by N-formyl-met-leu-phe-peptide.

In this study, we have investigated the effect of hydrophobic and hydrophilic unconjugated bile acids (UBAs)-ursodeoxycholic acid (UDCA), chenodeoxycholic acid (CDCA), lithocholic acid, and colic acid-on chemotaxis in adult and neonatal human polymorphonuclear leukocytes (PMNs). The trypan blue exclusion dye test was preliminarily performed to determine the toxicity of the studied UBAs on PMNs. N-formyl-methionyl-leucyl-phenylalanine (100 nM) was used as a chemoattractant.

Opposing functions of Ki- and Ha-Ras genes in the regulation of redox signals.

Ras p21 signaling is involved in multiple aspects of growth, differentiation, and stress response [1-2]. There is evidence pointing to superoxides as relays of Ras signaling messages. Chemicals with antioxidant activity suppress Ras-induced DNA synthesis.

Presence of CuZn superoxide dismutase in human serum lipoproteins.

It has previously been demonstrated that CuZn-superoxide dismutase (SOD) is secreted by several human cell lines. This suggests that the circulating enzyme derives from both hemolysis and peripheral tissues as a result of cellular secretion. In the present report, we evaluated the presence of CuZn-SOD in human serum lipoproteins by both enzyme-linked immunosorbent assay and Western blot analysis of immunoprecipitated lipoprotein samples.

Free fatty acids modulate LDL receptor activity in BHK-21 cells.

It has been shown that dietary fatty acids affect serum low density lipoprotein (LDL) levels, but the mechanism responsible for this effect is still under debate. Here we investigate the effect of different free fatty acids on LDL receptor activity in BHK-21 cells. These cells possess a classical LDL receptor strongly regulated by substances like 25-OH-cholesterol or lovastatin.

Secretion and increase of intracellular CuZn superoxide dismutase content in human neuroblastoma SK-N-BE cells subjected to oxidative stress.

CuZn superoxide dismutase (SOD) secretion was detected in media of [35S]cysteine-labeled human neuroblastoma SK-N-BE cells precipitated with antihuman CuZn SOD antibodies. The ability of Fe2+/ascorbate oxidative stress to induce CuZn SOD in SK-N-BE cells was evaluated by Western blot analysis. The results showed that, like human hepatocarcinoma cells and human fibroblasts, SK-N-BE cells secrete CuZn SOD.