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. 2013 Nov 18:7:216.
doi: 10.3389/fncel.2013.00216. eCollection 2013.

Early gene expression changes in spinal cord from SOD1(G93A) Amyotrophic Lateral Sclerosis animal model

Gabriela P de Oliveira  1 , Chrystian J Alves, Gerson Chadi
Affiliations

Early gene expression changes in spinal cord from SOD1(G93A) Amyotrophic Lateral Sclerosis animal model

Gabriela P de Oliveira et al. Front Cell Neurosci. .

Abstract

Amyotrophic Lateral Sclerosis (ALS) is an adult-onset and fast progression neurodegenerative disease that leads to the loss of motor neurons. Mechanisms of selective motor neuron loss in ALS are unknown. The early events occurring in the spinal cord that may contribute to motor neuron death are not described, neither astrocytes participation in the pre-symptomatic phases of the disease. In order to identify ALS early events, we performed a microarray analysis employing a whole mouse genome platform to evaluate the gene expression pattern of lumbar spinal cords of transgenic SOD1(G93A) mice and their littermate controls at pre-symptomatic ages of 40 and 80 days. Differentially expressed genes were identified by means of the Bioconductor packages Agi4×44Preprocess and limma. FunNet web based tool was used for analysis of over-represented pathways. Furthermore, immunolabeled astrocytes from 40 and 80 days old mice were submitted to laser microdissection and RNA was extracted for evaluation of a selected gene by qPCR. Statistical analysis has pointed to 492 differentially expressed genes (155 up and 337 down regulated) in 40 days and 1105 (433 up and 672 down) in 80 days old ALS mice. KEGG analysis demonstrated the over-represented pathways tight junction, antigen processing and presentation, oxidative phosphorylation, endocytosis, chemokine signaling pathway, ubiquitin mediated proteolysis and glutamatergic synapse at both pre-symptomatic ages. Ube2i gene expression was evaluated in astrocytes from both transgenic ages, being up regulated in 40 and 80 days astrocytes enriched samples. Our data points to important early molecular events occurring in pre-symptomatic phases of ALS in mouse model. Early SUMOylation process linked to astrocytes might account to non-autonomous cell toxicity in ALS. Further studies on the signaling pathways presented here may provide new insights to better understand the events triggering motor neuron death in this devastating disorder.

Keywords: ALS; SOD1G93A; astrocytes; laser microdissection; microarray; pre-symptomatic; spinal cord.

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Figures

Figure 1
Figure 1
KEGG pathways classification showing the number of transcripts up regulated and down regulated per category in 40 and 80 days pre-symptomatic SOD1G93A mice in relation to age matched wild-types. Bars on the left indicate the number of down regulated genes, and bars on the right indicate the number of up regulated genes, for each category.
Figure 2
Figure 2
Photomicrographs illustrating astrocyte laser microdissection process. (A) The quick GFAP immunofluorescence allows recognizing the astrocytic profiles (arrows). (B) Astrocytes (1 and 2) were then selected for microdissection. (C) After laser firing and microdissection, selected cells (arrows) can no longer be visualized in the tissue. Scale bars of 20 μm.
Figure 3
Figure 3
Graph shows relative fold change values for Ube2i in microdissected astrocytes from 40 and 80 days old SOD1G93A mice compared to the age matched wild-type controls (WT). Significant increases are seen in both transgenic astrocytes enriched samples. Results are presented as means ± s.e.m. from 3 samples used for each group. *p-value < 0.05, according to unpaired t-test.
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References

    1. Alves C. J., De Santana L. P., Dos Santos A. J., De Oliveira G. P., Duobles T., Scorisa J. M., et al. (2011). Early motor and electrophysiological changes in transgenic mouse model of amyotrophic lateral sclerosis and gender differences on clinical outcome. Brain Res. 1394, 90–104 10.1016/j.brainres.2011.02.060 - DOI - PubMed
    1. Andersen P. M., Al-Chalabi A. (2011). Clinical genetics of amyotrophic lateral sclerosis: what do we really know? Nat. Rev. Neurol. 7, 603–615 10.1038/nrneurol.2011.150 - DOI - PubMed
    1. Arhart R. W. (2010). A possible haemodynamic mechanism for amyotrophic lateral sclerosis. Med. Hypotheses 75, 341–346 10.1016/j.mehy.2010.03.017 - DOI - PubMed
    1. Basso M., Samengo G., Nardo G., Massignan T., D'alessandro G., Tartari S., et al. (2009). Characterization of detergent-insoluble proteins in ALS indicates a causal link between nitrative stress and aggregation in pathogenesis. PLoS ONE 4:e8130 10.1371/journal.pone.0008130 - DOI - PMC - PubMed
    1. Beghi E., Logroscino G., Chio A., Hardiman O., Mitchell D., Swingler R., et al. (2006). The epidemiology of ALS and the role of population-based registries. Biochim. Biophys. Acta 1762, 1150–1157 10.1016/j.bbadis.2006.09.008 - DOI - PubMed