Establishment of a Cell Model Based on FKBP12 Dimerization for Screening of FK506-like Neurotrophic Small Molecular Compounds

¹ Department of Molecular Immunology, Institute of Basic Medical Sciences, Beijing, China.
² Department of Molecular Drug Design, Institute of Pharmacology and Toxicology Sciences, Beijing, China.

^* To whom correspondence should be addressed. E-mail: liyan62033{at}yahoo.com.cn.

	Abstract

FK506 is an efficient immunosuppressive agent with an increasing number of clinical applications. It has been approved to prevent rejection in transplant patients and be efficacious in several autoimmune diseases. Its immunosuppressive activity results from binding to receptor proteins designated as immunophilins (i.e., FKBP12, FK506 binding protein). Recent studies have suggested that FK506 can promote neurite outgrowth as a 2nd activity. Furthermore, it has been shown that the neurotrophic property of FK506 is independent of its immunosuppressive action. Although the mechanism of its neurotrophic activity has not yet been well elucidated, FKBP12 is identified as a drug target, and much effort has been directed toward the design of FKBP12-binding molecules, which are neurotrophic but nonimmunosuppressive, for clinical use. In this present study, the authors constructed a stable cell line, which underwent apoptosis upon treatment by AP20187, a wholly synthesized, cell-permeable dimeric FK506 derivative, based on FKBP12-mBax dimerization. This AP20187-mediated apoptosis was rapidly reversed by the addition of an FKBP12-binding competitor molecule (FK506 or rapamycin), indicating that this cell line might be used to screen FK506 derivatives. Using the screening model, hundreds of synthetic FK506 analogs were analyzed. A promising compound, named N308, was obtained. The results showed that N308 could inhibit AP20187-induced gene-modified target cell apoptosis and elicit augmentation of neurite extension from both cultured PC-12 cells and chicken dorsal root ganglia cultures.

Key Words: FK506, neurotrophic, FKBP12 dimerization, Bax-mediated apoptosis, competitive inhibition, FKBP12 targeted compounds, preliminary screening, neurite extension

First published on February 20, 2006, doi:10.1177/1087057105285440

Journal of Biomolecular Screening 2006;11:225.

A more recent version of this article appeared on April 1, 2006


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?