Depletion of a fatty acid-binding protein impairs neurite outgrowth in PC12 cells.
Epithelial fatty acid-binding protein (E-FABP) is up-regulated in rat dorsal root ganglia after sciatic nerve crush and in differentiating neurons during development. The present study investigates the role of E-FABP during nerve growth factor (NGF)-mediated neurite outgrowth in PC12 cells. Undifferentiated PC12 cells express low levels of E-FABP, while NGF triggers a 6- and 8-fold induction of E-FABP mRNA and protein, respectively. Up-regulation of E-FABP mRNA occurs as early as 24 h after NGF treatment and remains highly expressed over the course of several days, corresponding to NGF-mediated neurite outgrowth. Withdrawal of NGF leads to down-regulation of E-FABP mRNA and retraction of neurites. Immunofluorescence microscopy reveals E-FABP immunoreactivity in the perinuclear cytoplasm, neurites and growth cones of NGF-differentiated cells. To examine the role of E-FABP during neurite outgrowth, PC12 cells were transfected with a constitutive antisense E-FABP vector to create the E-FABP-deficient line PC12-AS. By morphometric analysis, PC12-AS cells treated for 2, 4, and 7 days with NGF exhibited significantly decreased neurite expression relative to control (mock-transfected) cells. Taken together, these data indicate that E-FABP is important in normal NGF-mediated neurite outgrowth in PC12 cells, a finding that is consistent with a potential role in axonal development and regeneration.
Allen
G W
GW
Department of Physiology and Pharmacology and Center for Molecular Biology and Gene Therapy, Loma Linda School of Medicine, Loma Linda University, Mortenson Hall 142 LLU, Loma Linda, CA 92350, USA.
Liu
J W
JW
De León
M
M
D000818:Animals; D002352:Carrier Proteins / Q000235:genetics* / Q000502:physiology; D003593:Cytoplasm / Q000502:physiology; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D007700:Kinetics; D018996:Myelin P2 Protein / Q000235:genetics* / Q000502:physiology; D009363:Neoplasm Proteins; D020932:Nerve Growth Factor / Q000494:pharmacology*; D009419:Nerve Tissue Proteins; D016501:Neurites / Q000187:drug effects / Q000502:physiology*; D016716:PC12 Cells; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011994:Recombinant Proteins / Q000096:biosynthesis; D014162:Transfection
D002352:Carrier Proteins; C490174:Fabp7 protein, rat; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D018996:Myelin P2 Protein; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D020932:Nerve Growth Factor