Endothelin-1 (ET-1) stimulates vascular cell adhesion molecule (VCAM-1) expression, a process associated with arterial remodelling. However, the pathways activated by ET-1 that lead to VCAM-1 expression are not fully understood. It is reported that sphingomyelinases are necessary for VCAM-1 expression in response to cytokines. Our aim was to investigate the role of sphingomyelinases in ET-1-ind...

Tumor necrosis factor-alpha (TNF-alpha) is a proinflammatory cytokine that activates several signaling cascades. We determined the extent to which ceramide is a second messenger for TNF-alpha-induced signaling leading to cytoskeletal rearrangement in Rat2 fibroblasts. TNF-alpha, sphingomyelinase, or C(2)-ceramide induced tyrosine phosphorylation of focal adhesion kinase (FAK) and paxillin, and ...

Peptide hormones act to regulate apoptosis through activation of multiple pro- and anti-apoptotic signaling cascades of which lipid signaling events represent an important facet of the cellular rheostat that determines survival and death decisions. Activation of sphingomyelinase, which generates ceramide, is an intermediate in cellular stress responses and induction of apoptosis in many systems...

The metabolism of sphingomyelin (SPM) was investigated in Epstein-Barr virus-transformed lymphoid cell lines from normal individuals and from patients with Niemann-Pick disease Type A (deficient in the acid, lysosomal sphingomyelinase) and familial hypercholesterolemia (lacking the low density lipoprotein receptor). Cells were incubated with the following radioactive or fluorescent SPMs: [choli...

LPS is a constituent of cell walls of Gram-negative bacteria that, acting through the CD14/TLR4 receptor complex, causes strong proinflammatory activation of macrophages. In murine peritoneal macrophages and J774 cells, LPS at 1-2 ng/ml induced maximal TNF-α and MIP-2 release, and higher LPS concentrations were less effective, which suggested a negative control of LPS action. While studying the...

The molecular basis of Niemann-Pick disease, type A and B, has been confirmed by detection of mutations causing deficiency of the acid sphingomyelinase activity in the patients. It has been shown that mutations, which cause no activity of acid sphingomyelinase, are responsible for the type A and mutations which cause residual activities of the enzyme are responsible for the type B. Acid sphingo...

Nuclear sphingomyelin is a key molecule for cell proliferation. This molecule is organized with cholesterol and proteins to form specific lipid microdomains bound to the inner nuclear membrane where RNA is synthesized. Here, we have reported the ability of the sphingomyelin present in the nuclear microdomain to bind DNA and regulate its synthesis, and to highlight its role in cell proliferation...

AIMS Pulmonary infections with Pseudomonas aeruginosa are a serious clinical problem and are often lethal. Because many strains of P. aeruginosa are resistant to antibiotics, therapeutic options are limited. Neutrophils play an important role in the host's early acute defense against pulmonary P. aeruginosa. Therefore, it is important to define the mechanisms by which P. aeruginosa interacts wi...

Nieman-Pick disease (NPD) also known as acid sphingomyelinase deficiency (ASMD) is a rare autosomal recessive disorder of lysosomal storage which affects 1 in 250,000 individuals mainly belonging to the Ashkenazi Jew population. The prevalence varies across three main subtypes where type A and B 40,000 C 150,000 individuals, being more prevalent French-Acadian descent region Nova Scotia.

Short-chain C6-sphingomyelin is an artificial substrate that was used in an acid sphingomyelinase activity assay for a pilot screening study of patients with Niemann-Pick disease types A and B. Using previously published multiplex and single assay conditions, normal acid sphingomyelinase activity levels (i.e. false negative results) were observed in two sisters with Niemann-Pick B who were comp...