Distribution of immunophilin FKBP-12 protein and mRNA within the mammaliancochlea and cochlear nucleus

Immunophilin FK binding protein-12 (FKBP-12), the soluble receptor for the immunosuppressant drug FK506, is involved in a number of neuronal activitie s including increased nerve regeneration in the peripheral nervous system a nd enhanced recovery in animal models of nc uro degenerative diseases. In a ddition, FKBP-12 is tightly bound to the calcium release channel ryanodine receptor and physiologically interacts with the inositol 1,4,5-trisphosphat e receptor. In nearly all cell types, release of intracellular Ca (2+) and subsequent second messenger signaling involves activation of these ion chan nels. We determined the distribution of FKBP-12 within the mammalian cochle a and dorsal cochlear nucleus (DCN) in order to gain insight into Ca 2+ reg ulation within the cochlea and to possibly identify potential cellular targ ets for neuroimmunophilin ligands that may prove useful in protection and r ecovery following ototoxic insult. FKBP-12 protein and mRNA were found to b e abundant throughout rat and guinea pig cochlea and DCN. (C) 2001 Elsevier Science B.V. All rights reserved.