Fatty acid binding protein is induced in neurons of the dorsal root ganglia after peripheral nerve injury.
Peripheral nerve trauma induces the expression of genes presumed to be involved in the process of nerve degeneration and repair. In the present study, an in vivo paradigm was employed to identify molecules which may have important roles in these processes. A cDNA library was constructed with RNA extracted from rat dorsal root ganglia (DRG) 3 days after a sciatic nerve crush. After differential hybridization to this library, several cDNAs were identified that encoded mRNAs that were upregulated in the DRG ipsilateral to the crush injury, as opposed to the contralateral or naive DRG. Approximately 0.15% of all the clones screened were found to be induced. This report presents the types of induced sequences identified and characterizes one of them, DA11. The 0.7 kb DA11 full length cDNA clone contains a 405 nucleotide open reading frame that encodes a putative protein of 15.2 kDa (135 amino acid residues) and is a member of the family of fatty acid binding proteins (FABP). The DA11 protein differs by one amino acid residue from the sequence of the C-FAPB protein and by eight residues from the sequence of mal1, proteins found in rat and mouse skin, respectively. Northern and Western blot analyses showed that the DA11 mRNA and protein were induced in the injured DRG. Furthermore, studies using antibodies generated against DA11 found that the DA11-like immunoreactivity was more pronounced in the nuclei of neurons located in the DRG ipsilateral to the sciatic cut than those located in the contralateral DRG. The induction of DA11 mRNA and protein in DRG neurons suggests, for the first time, the involvement of a neuronal FABP in the process of degeneration and repair in the nervous system.
De León
M
M
Center for Molecular Biology and Gene Therapy, Loma Linda University, CA 92350, USA.
Welcher
A A
AA
Nahin
R H
RH
Liu
Y
Y
Ruda
M A
MA
Shooter
E M
EM
Molina
C A
CA
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000737:chemistry; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000096:biosynthesis; D005136:Eye Proteins; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism*; D005727:Ganglia, Spinal / Q000166:cytology / Q000378:metabolism*; D015723:Gene Library; D007150:Immunohistochemistry; D051379:Mice; D008969:Molecular Sequence Data; D018996:Myelin P2 Protein / Q000096:biosynthesis* / Q000737:chemistry; D009363:Neoplasm Proteins; D009409:Nerve Crush; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000737:chemistry; D009474:Neurons / Q000378:metabolism*; D059348:Peripheral Nerve Injuries; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000293:injuries / Q000378:metabolism; D015854:Up-Regulation
D002352:Carrier Proteins; D018076:DNA, Complementary; D005136:Eye Proteins; C082667:Fabp5 protein, mouse; C107356:Fabp5 protein, rat; C086936:Fabp7 protein, mouse; 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