[Show abstract][Hide abstract] ABSTRACT: Nonimmunosuppressant ligands, exemplified by GPI 1046 (1), for the peptidyl-prolyl isomerase FKBP12 have been found to unexpectedly possess powerful neuroprotective and neuroregenerative effects in vitro and in vivo. We have extensively explored the therapeutic utility of FKBP12 ligands based on analogues of proline and pipecolic acid. As part of our ongoing program to explore novel structural classes of FKBP12 ligands, we herein wish to report a new class of FKBP12 ligands containing aza-proline and aza-pipecolic acid analogues. Details of the synthetic studies, together with biological activity will be presented.
[Show abstract][Hide abstract] ABSTRACT: The recent discovery that small molecule ligands for the peptidyl-prolyl isomerase (PPIase) FKBP12 possess powerful neuroprotective and neuroregenerative properties in vitro and in vivo suggests therapeutic utility for such compounds in neurodegenerative disease. The neurotrophic effects of these compounds are independent of the immunosuppressive pathways by which drugs such as FK506 and rapamycin operate. Previous work by ourselves and other groups exploring the structure-activity relationships (SAR) of small molecules that mimic only the FKBP binding domain portion of FK506 has focused on esters of proline and pipecolic acid. We have explored amide and thioester analogues of these earlier structures and found that they too are extremely potent in promoting recovery of lesioned dopaminergic pathways in a mouse model of Parkinson's disease. Several compounds were shown to be highly effective upon oral administration after lesioning of the dopaminergic pathway, providing further evidence of the potential clinical utility of a variety of structural classes of FKBP12 ligands.
[Show abstract][Hide abstract] ABSTRACT: Using simple, inexpensive equipment, we have used solution-phase parallel synthesis to rapidly prepare hundreds of sulfonamide- and urea-containing FKBP inhibitors, resulting in rapid identification of extremely potent compounds in these series.
[Show abstract][Hide abstract] ABSTRACT: In parallel with our work on solution-phase parallel synthesis of ligands for the rotamase enzyme FKBP12, we herein report a methodology for the solid-phase synthesis of two classes of inhibitor, N-sulfonyl and N-carbamoylprolyl and pipecolyl amides along with their in vitro/in vivo biological results.
[Show abstract][Hide abstract] ABSTRACT: Extensive unilateral striatal deafferentation was produced by intranigral 6-hydroxydopamine (6-OHDA) in rats. Beginning 60 days after 6-OHDA injection animals received a 14-day course of treatment with either the small molecule FKBP ligand GPI 1046 (10 mg/kg) or its vehicle alone. Striatal dopaminergic innervation density was determined from high power image analysis of striatal tyrosine hydroxylase (TH) immunohistochemistry. GPI 1046 treatment did not alter TH fiber density in the contralateral striatum but did produce significantly higher striatal TH fiber density in the ipsilateral caudate-putamen. This striatal re-innervation occurred in the absence of increased nigral sparing, and appears to reflect the GPI 1046 induced sprouting of residual TH+ fibers spared by the 6-OHDA lesion.
[Show abstract][Hide abstract] ABSTRACT: Although immunosuppressant immunophilin ligands promote neurite outgrowth in vitro, their neurotrophic activities are clearly independent of their immunosuppressive activity. In the present report, a novel nonimmunosuppressive immunophilin ligand, GPI-1046 (3-(3-pyridyl)-1-propyl (2S)-1-(3,3-dimethyl-1,2-dioxopentyl)-2-pyrrolidinecarboxylate+ ++) is described. In vitro, GPI-1046 bound to FK506 binding protein-12 and elicited neurite outgrowth from sensory neuronal cultures with picomolar potency with maximal effects comparable to nerve growth factor. In vivo, GPI-1046 stimulated the regeneration of lesioned sciatic nerve axons and myelin levels. In the central nervous system, GPI-1046 promoted protection and/or sprouting of serotonin-containing nerve fibers in somatosensory cortex following parachloroamphetamine treatment. GPI-1046 also induced regenerative sprouting from spared nigrostriatal dopaminergic neurons following 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine toxicity in mice or 6-hydroxydopamine (6-OHDA) toxicity in rats. The rotational abnormality in 6-OHDA treated rats was alleviated by GPI-1046. These neurotrophic actions in multiple models suggest therapeutic utility for GPI-1046 in neurodegenerative diseases.
Proceedings of the National Academy of Sciences 04/1997; 94(5):2019-24. DOI:10.1073/pnas.94.5.2019 · 9.81 Impact Factor