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 Academic Article uri icon

  •  
  • Overview
  •  
  • Research
  •  
  • Identity
  •  
  • Additional Document Info
  •  
  • View All
  •  

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 APP(96-110) 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 beta-amyloid 1-42 (Abeta42), the neurotoxic APP fragment contained within neurodegenerative plaques in Alzheimer's Disease. Although both peptides elicited dysmorphogenesis, Abeta42 was far more potent; in addition, whereas Abeta42 produced abnormalities at developmental stages ranging from early cleavage divisions to the late pluteus, APP(96-110) 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 alpha-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.

authors

  • Milosevic, Irena
  • 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

publication date

  • November 2008