Ceramide and ceramide 1-phosphate are negative regulators of TNF-α production induced by lipopolysaccharide.

Ceramide and Ceramide 1-Phosphate Are Negative Regulators of TNF-a Production Induced by Lipopolysaccharide

Pseudomonas-Derived Ceramidase Induces Production of Inflammatory Mediators from Human Keratinocytes via Sphingosine-1-Phosphate

Ceramide is important for water retention and permeability barrier functions in the stratum corneum, and plays a key role in the pathogenesis of atopic dermatitis (AD). A Pseudomonas aeruginosa-derived neutral ceramidase (PaCDase) isolated from a patient with AD was shown to effectively degrade ceramide in the presence of Staphylococcus aureus-derived lipids or neutral detergents. However, the ...

Overexpression of Acid Ceramidase Protects from Tumor Necrosis Factor–Induced Cell Death

Tumor necrosis factor (TNF) signals cell death and simultaneously induces generation of ceramide. To evaluate the contribution of ceramide to TNF-dependent cell death, we generated clones of the TNF-sensitive cell line L929 that constitutively overexpress human acid ceramidase (AC). Ceramidase, in concert with sphingosine kinase, metabolizes ceramide to sphingosine-1-phosphate (SPP), an inducer...

Cytokine Response Modifier A (CrmA) Inhibits Ceramide Formation in Response to Tumor Necrosis Factor (TNF)-α: CrmA and Bcl-2 Target Distinct Components in the Apoptotic Pathway

Proteases are now firmly established as major regulators of the "execution" phase of apoptosis. Here, we examine the role of proteases and their relationship to ceramide, a proposed mediator of apoptosis, in the tumor necrosis factor-alpha (TNF-alpha)-induced pathway of cell death. Ceramide induced activation of prICE, the protease that cleaves the death substrate poly(ADP-ribose) polymerase. B...

Roles for C16-ceramide and sphingosine 1-phosphate in regulating hepatocyte apoptosis in response to tumor necrosis factor-alpha.

Tumor necrosis factor (TNF)-alpha signals cell death and simultaneously induces the generation of ceramide, which is metabolized to sphingosine and sphingosine 1-phosphate (S1P) by ceramidase (CDase) and sphingosine kinase. Because the dynamic balance between the intracellular levels of ceramide and S1P (the "ceramide/S1P rheostat") may determine cell survival, we investigated these sphingolipi...