Bone morphogenetic proteins and neurotrophins provide complementary protection of septal cholinergic function during phosphatase inhibitor-induced stress.
Cultures of embryonic rat septum were exposed for 24-48 h to 2-5 nm okadaic acid (OA), an inhibitor of pp1A and pp2A phosphatases. This stress killed approximately 75% of neurons. A neurotrophin (NT) combination (nerve growth factor and brain-derived neurotrophic factor, each 100 ng/mL) plus a bone morphogenetic protein (BMP6 or BMP7, 5 nm) reduced the death of both cholinergic and non-cholinergic neurons, and preserved choline acetyltransferase (ChAT) activity assayed 2-6 days post-stress. This NT + BMP combination preserved ChAT activity better than either NTs or BMPs alone, and was effective even if trophic factor addition was delayed until 12 h after stress onset. A general caspase inhibitor (qVD-OPH, 10 micro g/mL) also increased survival of stressed cholinergic neurons, but its protection of ChAT activity was shorter lived than that produced by the NT + BMP combination. Neither the NT + BMP combination nor the caspase inhibitor reduced the OA-induced increase in tau phosphorylation. These findings indicate that NTs and BMPs have synergistic protective effects against an OA stress, and suggest that at least some of these protective effects occur upstream of caspase activation.
Nonner
Doris
D
Department of Physiology and Biophysics, University of Miami School of Medicine, Miami, Florida 33101, USA.
Panickar
Kiran
K
Barrett
Ellen F
EF
Barrett
John N
JN
D000110:Acetylcholinesterase / Q000378:metabolism*; D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000627:therapeutic use*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D004622:Embryo, Mammalian; D004791:Enzyme Inhibitors / Q000633:toxicity; D005452:Fluoresceins / Q000378:metabolism; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins; D007150:Immunohistochemistry / Q000379:methods; D008387:Marine Toxins; D009414:Nerve Growth Factors / Q000627:therapeutic use*; D009687:Nuclear Proteins / Q000378:metabolism; D019319:Okadaic Acid / Q000633:toxicity; D010080:Oxazoles / Q000494:pharmacology; D010744:Phosphoric Monoester Hydrolases / Q000037:antagonists & inhibitors; D010766:Phosphorylation / Q000187:drug effects; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051381:Rats; D012686:Septal Nuclei / Q000166:cytology / Q000187:drug effects*; D013312:Stress, Physiological / Q000139:chemically induced / Q000517:prevention & control*; D013997:Time Factors; D014162:Transfection / Q000379:methods; D051020:bcl-X Protein; D016875:tau Proteins / Q000378:metabolism
C494813:Bcl2l1 protein, rat; D019485:Bone Morphogenetic Proteins; D004338:Drug Combinations; D004791:Enzyme Inhibitors; D005452:Fluoresceins; D005904:Glial Fibrillary Acidic Protein; D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D008387:Marine Toxins; D009414:Nerve Growth Factors; D009687:Nuclear Proteins; D010080:Oxazoles; D019253:Proto-Oncogene Proteins c-bcl-2; C549284:TRAP1 protein, rat; D051020:bcl-X Protein; D016875:tau Proteins; D019319:Okadaic Acid; C059041:calyculin A; D000110:Acetylcholinesterase; D010744:Phosphoric Monoester Hydrolases; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases; C007740:fluorexon