M. Teresa Solas

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.

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.

Improvement of Cold and Thermally Induced Gelation of Giant Squid (Dosidicus gigas) Surimi

Depending on the season of capture, giant squid (Dosidicus gigas) surimi processed by isoelectric precipitation presents low gel strength. Addition of microbial transglutaminase (MTGase) and application of high isostatic pressure (300 MPa) to improve physicochemical properties were assayed for purposes of making “suwari” gels and heated gels for use in restructured products which have a raw or cooked appearance. The physicochemical properties of both pressurized and unpressurized gels induced by application of 30°C/1 h improved when MTGase was added. In contrast, addition of MTGase was less effective in gels subsequently heated at 90°C/30 min after 30°C/1 h. High pressure treatment for 30 min at 300 MPa and 15°C helped to produce gels with better mechanical and water binding properties, whether treated for 30°C/1 h only or for 30°C/1 h plus 30-min heat treatment at 90°C. High pressure treatment also reduced lightness.

Small GSK-3 Inhibitor Shows Efficacy in a Motor Neuron Disease Murine Model Modulating Autophagy.

Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron degenerative disease that has no effective treatment up to date. Drug discovery tasks have been hampered due to the lack of knowledge in its molecular etiology together with the limited animal models for research. Recently, a motor neuron disease animal model has been developed using β-N-methylamino-L-alanine (L-BMAA), a neurotoxic amino acid related to the appearing of ALS. In the present work, the neuroprotective role of VP2.51, a small heterocyclic GSK-3 inhibitor, is analysed in this novel murine model together with the analysis of autophagy. VP2.51 daily administration for two weeks, starting the first day after L-BMAA treatment, leads to total recovery of neurological symptoms and prevents the activation of autophagic processes in rats. These results show that the L-BMAA murine model can be used to test the efficacy of new drugs. In addition, the results confirm the therapeutic potential of GSK-3 inhibitors, and specially VP2.51, for the disease-modifying future treatment of motor neuron disorders like ALS.