Role for furin in tumor necrosis factor alpha-induced activation of the matrix metalloproteinase/sphingolipid mitogenic pathway.
Neutral sphingomyelinase (nSMase), the initial enzyme of the sphingolipid signaling pathway, is thought to play a key role in cellular responses to tumor necrosis factor alpha (TNF-alpha), such as inflammation, proliferation, and apoptosis. The mechanism of TNF-alpha-induced nSMase activation is only partly understood. Using biochemical, molecular, and pharmacological approaches, we found that nSMase activation triggered by TNF-alpha is required for TNF-alpha-induced proliferation and in turn requires a proteolytic cascade involving furin, membrane type 1 matrix metalloproteinase (MT1-MMP), and MMP2, and leading finally to extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and DNA synthesis, in smooth muscle cells (SMC) and fibroblasts. Pharmacological and molecular inhibitors of MMPs (batimastat), furin (alpha1-PDX inhibitor-transfected SMC), MT1-MMP (SMC overexpressing a catalytically inactive MT1-MMP), MMP2 (fibroblasts from MMP2(-/-) mice), and small interfering RNA (siRNA) strategies (siRNAs targeting furin, MT1-MMP, MMP2, and nSMase) resulted in near-complete inhibition of the activation of nSMase, sphingosine kinase-1, and ERK1/2 and of subsequent DNA synthesis. Exogenous MT1-MMP activated nSMase and SMC proliferation in normal but not in MMP2(-/-) fibroblasts, whereas exogenous MMP2 was active on both normal and MMP2(-/-) fibroblasts. Altogether these findings highlight a pivotal role for furin, MT1-MMP, and MMP2 in TNF-alpha-induced sphingolipid signaling, and they identify this system as a possible target to inhibit SMC proliferation in vascular diseases.
Tellier
Edwige
E
INSERM U466, Biochimie, IFR-31, CHU Rangueil, 1, Avenue Jean Poulhès, TSA-50032, 31059 Toulouse Cedex 9, France.
Nègre-Salvayre
Anne
A
Bocquet
Beatrice
B
Itohara
Shigeyoshi
S
Hannun
Yusuf A
YA
Salvayre
Robert
R
Augé
Nathalie
N
D000818:Animals; D020126:Brefeldin A / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D002518:Ceramides / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D045683:Furin / Q000378:metabolism*; D006801:Humans; D008246:Lysophospholipids / Q000378:metabolism; D053511:Matrix Metalloproteinase 14 / Q000378:metabolism*; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D051379:Mice; D008934:Mitogens / Q000378:metabolism*; D008954:Models, Biological; D008985:Monensin / Q000494:pharmacology; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000201:enzymology; D011817:Rabbits; D015398:Signal Transduction / Q000187:drug effects; D013107:Sphingolipids / Q000378:metabolism*; D013108:Sphingomyelin Phosphodiesterase / Q000378:metabolism; D013109:Sphingomyelins / Q000378:metabolism; D013110:Sphingosine / Q000031:analogs & derivatives / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D021601:trans-Golgi Network / Q000187:drug effects
D002518:Ceramides; D008246:Lysophospholipids; D008934:Mitogens; D013107:Sphingolipids; D013109:Sphingomyelins; D014409:Tumor Necrosis Factor-alpha; D020126:Brefeldin A; C060506:sphingosine 1-phosphate; D008985:Monensin; C491484:SMPD3 protein, human; D013108:Sphingomyelin Phosphodiesterase; D045683:Furin; D020778:Matrix Metalloproteinase 2; D053511:Matrix Metalloproteinase 14; D013110:Sphingosine