β-N-methylamino-l-alanine causes neurological and pathological phenotypes mimicking Amyotrophic Lateral Sclerosis (ALS): the first step towards an experimental model for sporadic ALS

Environ Toxicol Pharmacol. 2013 Sep;36(2):243-255. doi: 10.1016/j.etap.2013.04.007. Epub 2013 Apr 25.

Abstract

β-N-methylamino-l-alanine (L-BMAA) is a neurotoxic amino acid that has been related to various neurodegenerative diseases. The aim of this work was to analyze the biotoxicity produced by L-BMAA in vivo in rats, trying to elucidate its physiopathological mechanisms and to search for analogies between the found effects and pathologies like Amyotrophic Lateral Sclerosis (ALS). Our data demonstrated that the neurotoxic effects in vivo were dosage-dependent. For evaluating the state of the animals, a neurological evaluation scale was developed as well as a set of functional tests. Ultrastructural cell analysis of spinal motoneurons has revealed alterations both in endoplasmic reticulum and mitochondria. Since GSK3β could play a role in some neuropathological processes, we analyzed the alterations occurring in GSK3β levels in L-BMAA treated rats, we have observed an increase in the active form of GSK3β levels in lumbar spinal cord and motor cerebral cortex. On the other hand, (TAR)-DNA-binding protein 43 (TDP-43) increased in L-BMAA treated animals. Our results indicated that N-acetylaspartate (NAA) declined in animals treated with L-BMAA, and the ratio of N-acetylaspartate/choline (NAA/Cho), N-acetylaspartate/creatine (NAA/Cr) and N-acetylaspartate/choline+creatine (NAA/Cho+Cr) tended to decrease in lumbar spinal cord and motor cortex. This project offers some encouraging results that could help establishing the progress in the development of an animal model of sporadic ALS and L-BMAA could be a useful tool for this purpose.

Keywords: (TAR)-DNA-binding protein 43; ALS; ALS-PDC; Amyotrophic Lateral Sclerosis; Amyotrophic Lateral Sclerosis/Parkinson-Dementia complex; Cho; Cr; ER; GSK3β; L-BMAA; Lumbar spinal cord; Motor cortex; N-acetylaspartate; NAA; Rat sporadic Amyotrophic Lateral Sclerosis model; TDP-43; choline; creatine; endoplasmic reticulum; glycogen synthase kinase-3β; β-N-methylamino-l-alanine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids, Diamino*
  • Amyotrophic Lateral Sclerosis / chemically induced*
  • Amyotrophic Lateral Sclerosis / metabolism
  • Amyotrophic Lateral Sclerosis / pathology
  • Amyotrophic Lateral Sclerosis / physiopathology
  • Animals
  • Aspartic Acid / analogs & derivatives
  • Aspartic Acid / metabolism
  • Caspase 3 / metabolism
  • Choline / metabolism
  • Creatinine / metabolism
  • DNA-Binding Proteins / metabolism
  • Disease Models, Animal
  • Endoplasmic Reticulum / metabolism
  • Endoplasmic Reticulum / pathology
  • Glycogen Synthase Kinase 3 / metabolism
  • Glycogen Synthase Kinase 3 beta
  • Magnetic Resonance Spectroscopy
  • Male
  • Mitochondria / metabolism
  • Mitochondria / pathology
  • Motor Activity
  • Motor Cortex / metabolism
  • Motor Cortex / pathology*
  • Motor Cortex / physiopathology
  • Nerve Degeneration*
  • Neurologic Examination
  • Phenotype
  • Rats
  • Rats, Wistar
  • Spinal Cord / metabolism
  • Spinal Cord / pathology*
  • Spinal Cord / physiopathology
  • Time Factors

Substances

  • Amino Acids, Diamino
  • DNA-Binding Proteins
  • beta-N-methylamino-L-alanine
  • Aspartic Acid
  • N-acetylaspartate
  • Creatinine
  • Glycogen Synthase Kinase 3 beta
  • Gsk3b protein, rat
  • Glycogen Synthase Kinase 3
  • Casp3 protein, rat
  • Caspase 3
  • Choline