Microarray Analysis of the Cellular Pathways Involved in the Adaptation to and Progression of Motor Neuron Injury in the SOD1 G93A Mouse Model of Familial ALS

Abstract

The cellular pathways of motor neuronal injury have been investigated in the SOD1 G93A murine model of familial amyotrophic lateral sclerosis (ALS) using laser-capture microdissection and microarray analysis. The advantages of this study include the following: analysis of changes specifically in motor neurons (MNs), while still detecting effects of interactions with neighboring cells; the ability to profile changes during disease progression, an approach not possible in human ALS; and the use of transgenic mice bred on a homogeneous genetic background, eliminating the confounding effects arising from a mixed genetic background. By using this rigorous approach, novel changes in key cellular pathways have been detected at both the presymptomatic and late stages,

Production of RNA for Transcriptomic Analysis from Mouse Spinal Cord Motor Neuron Cell Bodies by Laser Capture Microdissection

“…Notably, Azure B staining did not affect either the integrity of the purified RNA or its ability to be reverse-transcribed and analyzed. Other dyes, such as cresyl violet 7 and toluidine blue 8 have been used in similar LMD protocols.…”

Combined lithium and valproate treatment delays disease onset, reduces neurological deficits and prolongs survival in an amyotrophic lateral sclerosis mouse model

“…VPA and another HDAC inhibitor, phenylbutyrate, have also been shown to upregulate Bcl-2 in G86R and G93A ALS mice (Ryu et al, 2005;Rouaux et al, 2007). Recent microarray analysis revealed that the course of disease progression in G93A mice is associated with marked transcriptional repression of genes involved in transcriptional and metabolic functions, and increased expression of cyclins functioning in cell cycle regulation (Ferraiuolo et al, 2007). Clearly, further studies are necessary to identify the set of genes critically involved in the beneficial actions of combined treatment with lithium and VPA.…”

Insights Arising from Gene Expression Profiling in Amyotrophic Lateral Sclerosis

“…One of the major advantages of using animal models for microarray analysis is the ability to examine animals at different ages in order to investigate the progression of disease, an approach that is unattainable in human post-mortem tissue. Valuable insights regarding onset of disease can be established in pre-symptomatic and early symptomatic disease stages since these represent time points at which the identification of key novel targets for therapeutic intervention could be best placed to rescue vulnerable neuronal cell populations before the development of irreversible neuronal injury (Ferraiuolo et al 2007). In addition, sampling of specific cell types from the CNS allow gene expression changes to be identified which include the effects of interactions with neighbouring cells.…”

“…In addition, sampling of specific cell types from the CNS allow gene expression changes to be identified which include the effects of interactions with neighbouring cells. Backcrossing of the SOD1 WT and SOD1 G93A mice with C57Bl6 mice has led to the formation of SOD1 WT and SOD1 G93A mice on a homogeneous background (Ferraiuolo et al 2007). The use of these mice for microarray analysis and the use of non-transgenic littermates as controls have proven effective in reducing inter-individual genetic variability to ensure the generation of consistent and reliable gene expression data.…”

“…Laser capture microdissection (LCM) may be a more expensive and laborious technique but is beneficial in studying a neuronal enriched cell population (Jiang et al 2005). It also is noteworthy that in comparison to primary cultures these cells have had the benefit of being embedded within their natural environment where physiologically relevant cross talk has taken place with neighbouring cells and tissues (Ferraiuolo et al 2007).…”