neural-stem-cell-transplantation-experimental-contusive-model-spinal

Neural Stem Cell Transplantation in Experimental Contusive Model of Spinal Cord Injury

Spinal cord injury is a devastating clinical condition, characterized by a complex of neurological dysfunctions. Animal models of spinal cord injury can ...

The possibility to visualize and image the arrangement of proteins within the cell at the molecular level has always been an attraction for scientists in biological research. In particular, for signalling molecules such as GPCRs (G-protein-coupled receptors), the existence of protein aggregates such as oligomers or clusters has been the topic of extensive debate. One of the reasons for this lively argument is that the molecular size is below the diffraction-limited resolution of the conventional microscopy, precluding the direct visualization of protein super-structures. On the other hand, new super-resolution microscopy techniques, such as the PALM (photoactivated localization microscopy), allow the limit of the resolution power of conventional optics to be broken and the localization of single molecules to be determined with a precision of 10-20 nm, close to their molecular size. The application of super-resolution microscopy to study the spatial and temporal organization of GPCRs has brought new insights into receptor arrangement on the plasma membrane. Furthermore, the use of this powerful microscopy technique as a quantitative tool opens up the possibility for investigating and quantifying the number of molecules in biological assemblies and determining the protein stoichiometry in signalling complexes.

Enlightening G-protein-coupled receptors on the plasma membrane using super-resolution photoactivated localization microscopy.

The present review update the relationship between acetaldehyde (ACE) and parkinsonism with a specific focus on the role of P450 system and CYP 2E1 isozyme particularly. We have indicated that ACE is able to enhance the parkinsonism induced in mice by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, a neurotoxin able to damage the nigrostriatal dopaminergic pathway. Similarly diethyldithiocarbamate, the main metabolite of disulfiram, a drug widely used to control alcoholism, diallylsulfide (DAS) and phenylisothiocyanate also markedly enhance the toxin-related parkinsonism. All these compounds are substrate/inhibitors of CYP450 2E1 isozyme. The presence of CYP 2E1 has been detected in the dopamine (DA) neurons of rodent Substantia Nigra (SN), but a precise function of the enzyme has not been elucidated yet. By treating CYP 2E1 knockout (KO) mice with the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, the SN induced lesion was significantly reduced when compared with the lesion observed in wild-type animals. Several in vivo and in vitro studies led to the conclusion that CYP 2E1 may enhance the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine toxicity in mice by increasing free radical production inside the dopaminergic neurons. ACE is a good substrate for CYP 2E1 enzyme as the other substrate-inhibitors and by this way may facilitate the susceptibility of dopaminergic neurons to toxic events. The literature suggests that ethanol and/or disulfiram may be responsible for toxic parkinsonism in human and it indicates that basal ganglia are the major targets of disulfiram toxicity. A very recent study reports that there are a decreased methylation of the CYP 2E1 gene and increased expression of CYP 2E1 mRNA in Parkinson's disease (PD) patient brains. This study suggests that epigenetic variants of this cytochrome contribute to the susceptibility, thus confirming multiples lines of evidence which indicate a link between environmental toxins and PD.

Article	Year
Enlightening G-protein-coupled receptors on the plasma membrane using super-resolution photoactivated localization microscopy. Biochemical Society transactions\| PubMed ID: 23356282	2013
Acetaldehyde and parkinsonism: role of CYP450 2E1. Frontiers in behavioral neuroscience\| PubMed ID: 23801948	2013

Claudio Gerace

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