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 pres ent study, an in vivo paradigm was employed to identify molecules whic h may have important roles in these processes, A cDNA library was cons tructed with RNA extracted from rat dorsal root ganglia (DRG) 3 days a fter a sciatic nerve crush, After differential hybridization to this l ibrary, several cDNAs were identified that encoded mRNAs that were upr egulated in the DRG ipsilateral to the crush injury, as opposed to the contralateral or naive DRG, Approximately 0.15% of all the clones scr eened were found to be induced, This report presents the types of indu ced 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 resi dues) and is a member of the family of fatty acid binding proteins (FA BP), The DA11 protein differs by one amino acid residue from the seque nce of the C-FAPB protein and by eight residues from the sequence of m all, proteins found in rat and mouse skin, respectively, Northern and Western blot analyses showed that the DA11 mRNA and protein were induc ed in the injured DRG, Furthermore, studies using antibodies generated against DA11 found that the DA11-like immunoreactivity was more prono unced in the nuclei of neurons located in the DRG ipsilateral to the s ciatic 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. (C) 1996 Wiley-Liss, Inc.