Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2007-5-21
pubmed:abstractText
The clinical immunosuppressant FTY720 is a sphingosine analogue that, once phosphorylated by sphingosine kinase 2 (Sphk2), is an agonist of multiple receptor subtypes for sphingosine 1-phosphate. Short exposures to FTY720 afford long term protection in lymphoproliferative and autoimmune disease models, presumably by inducing apoptosis in subsets of cells essential for pathogenesis. Sphingosine itself is pro-apoptotic, and apoptosis induced with FTY720 or sphingosine is thought to proceed independently of their phosphorylation. Following chemical mutagenesis of Jurkat cells we isolated mutants that are selectively resistant to FTY720 analogue AAL(R), as well as natural sphingolipid bases, including sphingosine. Cells lacking functional Sphk2 were resistant to apoptosis induced with AAL(R), indicating that apoptosis proceeds through AAL(R) phosphorylation. Phosphorylation of AAL(R) was also required for induction of lymphocyte apoptosis in mice, as apoptosis was not induced with the non-phosphorylatable chiral analogue, AAL(S). Apoptosis was induced in the spleen but not the thymus of mice administered 1 mg/kg AAL(R), correlating with levels of AAL(R)-phosphate (AFD(R)) in organ extracts. AFD(R) did not induce apoptosis when added to the cell culture medium, indicating that it induces apoptosis through an intracellular target. NBD-labeled AAL(R) localized to the endoplasmic reticulum, and AAL(R) treatment resulted in elevated cytosolic calcium, Bax redistribution from cytosol to mitochondrial and endoplasmic reticulum membranes, and caspase-independent mitochondrial permeabilization in Jurkat cells. We therefore describe an apoptotic pathway triggered by intracellular accumulation of sphingolipid base phosphates and suggest that sphingoid base substrates for Sphk2 acting intracellularly could be useful in the treatment of lymphoproliferative diseases.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
282
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
15833-42
pubmed:dateRevised
2008-6-5
pubmed:meshHeading
pubmed-meshheading:17400555-Animals, pubmed-meshheading:17400555-Apoptosis, pubmed-meshheading:17400555-Autoimmune Diseases, pubmed-meshheading:17400555-Calcium Signaling, pubmed-meshheading:17400555-Caspases, pubmed-meshheading:17400555-Cell Membrane Permeability, pubmed-meshheading:17400555-Drug Resistance, Neoplasm, pubmed-meshheading:17400555-Endoplasmic Reticulum, pubmed-meshheading:17400555-HeLa Cells, pubmed-meshheading:17400555-Humans, pubmed-meshheading:17400555-Immunosuppressive Agents, pubmed-meshheading:17400555-Jurkat Cells, pubmed-meshheading:17400555-Lymphoproliferative Disorders, pubmed-meshheading:17400555-Mice, pubmed-meshheading:17400555-Mice, Knockout, pubmed-meshheading:17400555-Mitochondria, pubmed-meshheading:17400555-Mutagenesis, pubmed-meshheading:17400555-Organ Specificity, pubmed-meshheading:17400555-Phosphorylation, pubmed-meshheading:17400555-Phosphotransferases (Alcohol Group Acceptor), pubmed-meshheading:17400555-Propylene Glycols, pubmed-meshheading:17400555-Protein Transport, pubmed-meshheading:17400555-Receptors, Lysosphingolipid, pubmed-meshheading:17400555-Sphingolipids, pubmed-meshheading:17400555-Sphingosine, pubmed-meshheading:17400555-Spleen, pubmed-meshheading:17400555-Thymus Gland, pubmed-meshheading:17400555-bcl-2-Associated X Protein
pubmed:year
2007
pubmed:articleTitle
Essential requirement for sphingosine kinase 2 in a sphingolipid apoptosis pathway activated by FTY720 analogues.
pubmed:affiliation
Departments of Immunology and Chemistry, The Scripps Research Institute, La Jolla, California 92037, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural