Simultaneous Quantitative Analysis of Sphingoid Base 1-Phosphates in Biological Samples by o-Phthalaldehyde Precolumn Derivatization after Dephosphorylation with Alkaline Phosphatase

Min, Jung Kee; Yoo, Hwan‐Soo; Lee, Eun-Young; Lee, Woojin; Lee, Young Moo

doi:10.1006/abio.2002.5579

Cited by 147 publications

(111 citation statements)

References 17 publications

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“…This step requires either direct or indirect interactions of FADD with surface receptors possessing death domains, such as Fas or tumor necrosis factor receptor (25,26). To determine the involvement of the death receptor in sphingosine-induced apoptosis, we immunoprecipitated FADD, followed by immunoblotting for caspase-8.…”

Section: Caspase-dependent Apoptotic Cell Death In Response To Sphingmentioning

confidence: 99%

Activation of p38 Mitogen-Activated Protein Kinase Is Required for Death Receptor–Independent Caspase-8 Activation and Cell Death in Response to Sphingosine

Yoon

Kim

Park

et al. 2009

Molecular Cancer Research

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Sphingosine induces activation of multiple signaling pathways that play critical roles in controlling cell death. However, the precise molecular mechanism of cell death induced by sphingosine remains to be clarified. In this study, we show that sphingosine induces death receptor -independent caspase-8 activation and apoptotic cell death via p38 mitogen-activated protein kinase (MAPK) activation and that suppression of the MAPK/extracellular signal -regulated kinase (ERK) kinase/ERK pathway by protein phosphatase 2A (PP2A) is required for p38 MAPK activation. Treatment of cells with sphingosine induced suppression of ERK and activation of p38 MAPK. Inhibition of p38 MAPK led to the marked suppression of death receptor -independent caspase-8 activation and subsequent cell death induced by sphingosine. Interestingly, pretreatment with phorbol 12-myristate 13-acetate or transfection of MAPK/ERK kinase/ERK resulting in ERK activation completely attenuated sphingosine-induced p38 MAPK activation. PP2A activity was additionally elevated on sphingosine treatment. Small interfering RNA targeting of PP2A effectively attenuated sphingosine-induced p38 MAPK activation through restoration of ERK activity, suggesting PP2A-mediated opposing regulation of ERK and p38 MAPK. Our findings clearly imply that activation of p38 MAPK promotes death receptor -independent activation of caspase-8 and apoptotic cell death pathways, thus providing a novel cellular mechanism for the anticancer activity of sphingolipid metabolites.

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Section: Caspase-dependent Apoptotic Cell Death In Response To Sphingmentioning

confidence: 99%

Activation of p38 Mitogen-Activated Protein Kinase Is Required for Death Receptor–Independent Caspase-8 Activation and Cell Death in Response to Sphingosine

Yoon

Kim

Park

et al. 2009

Molecular Cancer Research

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“…The amounts of Sph and S1P were measured by HPLC (Agilent 1100 series; Agilent Technologies) after derivatization with o -phthalaldehyde essentially as described elsewhere (25).…”

Section: Determination Of Sph and S1p Levels By Hplcmentioning

confidence: 99%

Mechanisms of sphingosine and sphingosine 1-phosphate generation in human platelets

Tani

Sano

Ito

et al. 2005

Journal of Lipid Research

104

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The bioactive molecule sphingosine 1-phosphate (S1P) is abundantly stored in platelets and can be released extracellularly. However, although they have high sphingosine (Sph) kinase activity, platelets lack the de novo sphingolipid biosynthesis necessary to provide the substrates. Here, we reveal a generation pathway for Sph, the precursor of S1P, in human platelets. Platelets incorporated extracellular 3 Hlabeled Sph much faster than human megakaryoblastic cells and rapidly converted it to S1P. Furthermore, Sph formed from plasma sphingomyelin (SM) by bacterial sphingomyelinase (SMase) and neutral ceramidase (CDase) was rapidly incorporated into platelets and converted to S1P, suggesting that platelets use extracellular Sph as a source of S1P. Platelets abundantly express SM, possibly supplied from plasma lipoproteins, at the cell surface. Treating platelets with bacterial SMase resulted in Sph generation at the cell surface, conceivably by the action of membrane-bound neutral CDase. Simultaneously, a time-dependent increase in S1P levels was observed. Finally, we demonstrated that secretory acid SMase also induces S1P increases in platelets. In conclusion, our results suggest that in platelets, Sph is supplied from at least two sources: generation in the plasma followed by incorporation, and generation at the outer leaflet of the plasma membrane, initiated by cell surface SM degradation.

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“…HPLC assay was used to quantitate the released S1P and Sph, as described by Min et al [14] and applied in our laboratory [7]. Glomeruli pellets were resuspended in 100 ll phosphate-buffered saline (PBS) and an aliquot was kept for protein determination.…”

Section: Measurement Of Biochemical Parameters -Enzyme Assaysmentioning

confidence: 99%

Glomerular proliferation during early stages of diabetic nephropathy is associated with local increase of sphingosine‐1‐phosphate levels

et al. 2005

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In this study, the effects of short-term diabetes (4 days) on rat renal glomerular cells proliferation and the potential involvement of sphingolipids in this process were investigated. Immunohistochemical analysis showed that streptozotocin (STZ)-induced diabetes promoted increased intra-glomerular hyperplasia, particularly marked for mesangial cells. This was associated with a concomitant increase in neutral ceramidase and sphingosine-kinase activities and the accumulation of the pro-proliferative sphingolipid sphingosine-1-phosphate, in glomeruli isolated from kidney cortex of STZ-treated rats. These results suggest a possible involvement of sphingolipid metabolites in the glomerular proliferative response during the early stages of diabetic nephropathy.

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Simultaneous Quantitative Analysis of Sphingoid Base 1-Phosphates in Biological Samples by o-Phthalaldehyde Precolumn Derivatization after Dephosphorylation with Alkaline Phosphatase

Cited by 147 publications

References 17 publications

Activation of p38 Mitogen-Activated Protein Kinase Is Required for Death Receptor–Independent Caspase-8 Activation and Cell Death in Response to Sphingosine

Activation of p38 Mitogen-Activated Protein Kinase Is Required for Death Receptor–Independent Caspase-8 Activation and Cell Death in Response to Sphingosine

Mechanisms of sphingosine and sphingosine 1-phosphate generation in human platelets

Glomerular proliferation during early stages of diabetic nephropathy is associated with local increase of sphingosine‐1‐phosphate levels

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