Amyloid precursor protein 96–110 and β-amyloid 1–42 elicit developmental anomalies in sea urchin embryos and larvae that are alleviated by neurotransmitter analogs for acetylcholine, serotonin and cannabinoids

• Published in: Neurotoxicology and teratology Vol. 30; no. 6; pp. 503 - 509
• Main Authors: Buznikov, Gennady A, Nikitina, Lyudmila A, Seidler, Frederic J, Slotkin, Theodore A, Bezuglov, Vladimir V, Milošević, Ivan, Lazarević, Lidija, Rogač, Ljubica, Ruzdijić, Sabera, Rakić, Ljubiša M
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-11-2008
• Subjects: Acetylcholine; Acetylcholine - analogs & derivatives; Acetylcholine - metabolism; Amyloid beta-Peptides - pharmacology; Amyloid beta-Protein Precursor - pharmacology; Amyloid precursor protein; Animals; Cannabinoids; Cannabinoids - agonists; Cannabinoids - metabolism; Cannabinoids - pharmacology; Chlorpyrifos - pharmacology; Development; Dose-Response Relationship, Drug; Drug Interactions; Embryo, Nonmammalian; Embryonic Development - drug effects; Emergency; Larva - drug effects; Medical Education; Peptide Fragments - pharmacology; Sea urchin embryo; Sea Urchins - drug effects; Sea Urchins - growth & development; Serotonin; Serotonin - analogs & derivatives; Serotonin - metabolism; Serotonin - pharmacology; Time Factors; β-Amyloid; AA-5HT; AA-DMAE; 5HT; AA-VAN; N, N, N,-trimethyl 5HT; ACh; 5-hydroxytryptamine, serotonin; 3-isobutyl-1-methylxanthine; arachidonoyl serotonin (arachidonoyl 5-hydroxytryptamine); Cannabinoids; Sea urchin embryo; arachidonoyl vanillylamine; artificial sea water; arachidonoyl dimethylaminoethanol; Development; amyloid precursor protein 96–110; Aβ42; Serotonin; ASW; IBMX; 5HTQ; Amyloid precursor protein; β-amyloid 1–42; β-Amyloid; APP 96–110; acetylcholine; Acetylcholine
• ISSN: 0892-0362; 1872-9738
• DOI: 10.1016/j.ntt.2008.05.003

Abstract Amyloid precursor protein (APP) is overexpressed in the developing brain and portions of its extracellular domain, especially amino acid residues 96–110, play an important role in neurite outgrowth and neural cell differentiation. In the current study, we evaluated the developmental abnormalities caused by administration of exogenous APP96–110 in sea urchin embryos and larvae, which, like the developing mammalian brain, utilize acetylcholine and other neurotransmitters as morphogens; effects were compared to those of β-amyloid 1–42 (Aβ42), the neurotoxic APP fragment contained within neurodegenerative plaques in Alzheimer's Disease. Although both peptides elicited dysmorphogenesis, Aβ42 was far more potent; in addition, whereas Aβ42 produced abnormalities at developmental stages ranging from early cleavage divisions to the late pluteus, APP96–110 effects were restricted to the intermediate, mid-blastula stage. For both agents, anomalies were prevented or reduced by addition of lipid-permeable analogs of acetylcholine, serotonin or cannabinoids; physostigmine, a carbamate-derived cholinesterase inhibitor, was also effective. In contrast, agents that act on NMDA receptors (memantine) or α-adrenergic receptors (nicergoline), and that are therapeutic in Alzheimer's Disease, were themselves embryotoxic, as was tacrine, a cholinesterase inhibitor from a different chemical class than physostigmine. Protection was also provided by agents acting downstream from receptor-mediated events: increasing cyclic AMP with caffeine or isobutylmethylxanthine, or administering the antioxidant, a-tocopherol, were all partially effective. Our findings reinforce a role for APP in development and point to specific interactions with neurotransmitter systems that act as morphogens in developing sea urchins as well as in the mammalian brain.