Effects of lithium and valproic acid on gene expression and phenotypic markers in an NT2 neurosphere model of neural development

• Published in: PloS one Vol. 8; no. 3; p. e58822
• Main Authors: Hill, Eric J, Nagel, David A, O'Neil, John D, Torr, Elizabeth, Woehrling, Elizabeth K, Devitt, Andrew, Coleman, Michael D
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 19.03.2013; Public Library of Science (PLoS)
• Subjects: Acids; Aging; Analysis; Anchors; Astrocytes; Biology; Biomarkers; Bipolar disorder; Cancer; Cell Culture Techniques; Cell cycle; Cell Cycle - drug effects; Cell growth; Cell Line; Cell number; Cell Proliferation - drug effects; Cytometry; Divalproex; Drug development; Drugs; Epilepsy; Exposure; Flow cytometry; Gene expression; Gene Expression Profiling; Gene Expression Regulation - drug effects; Genes; Genetic aspects; Genomes; Genomics; Glial fibrillary acidic protein; Health sciences; Humans; Lithium; Lithium chloride; Lithium Chloride - pharmacology; Lithium chlorides; Medicine; Molecular Sequence Annotation; Mood; Neurogenesis - drug effects; Neurotrophin 2; Oct-4 protein; Octamer Transcription Factor-3 - genetics; Octamer Transcription Factor-3 - metabolism; Ontology; Pharmacology; Phenotype; Protein expression; Reproducibility of Results; Stage-Specific Embryonic Antigens - genetics; Stage-Specific Embryonic Antigens - metabolism; Stem cells; Toxicity; Toxicology; Valproic acid; Valproic Acid - pharmacology; United Kingdom > UK
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0058822

Mood stabilising drugs such as lithium (LiCl) and valproic acid (VPA) are the first line agents for treating conditions such as Bipolar disorder and Epilepsy. However, these drugs have potential developmental effects that are not fully understood. This study explores the use of a simple human neurosphere-based in vitro model to characterise the pharmacological and toxicological effects of LiCl and VPA using gene expression changes linked to phenotypic alterations in cells. Treatment with VPA and LiCl resulted in the differential expression of 331 and 164 genes respectively. In the subset of VPA targeted genes, 114 were downregulated whilst 217 genes were upregulated. In the subset of LiCl targeted genes, 73 were downregulated and 91 were upregulated. Gene ontology (GO) term enrichment analysis was used to highlight the most relevant GO terms associated with a given gene list following toxin exposure. In addition, in order to phenotypically anchor the gene expression data, changes in the heterogeneity of cell subtype populations and cell cycle phase were monitored using flow cytometry. Whilst LiCl exposure did not significantly alter the proportion of cells expressing markers for stem cells/undifferentiated cells (Oct4, SSEA4), neurons (Neurofilament M), astrocytes (GFAP) or cell cycle phase, the drug caused a 1.4-fold increase in total cell number. In contrast, exposure to VPA resulted in significant upregulation of Oct4, SSEA, Neurofilament M and GFAP with significant decreases in both G2/M phase cells and cell number. This neurosphere model might provide the basis of a human-based cellular approach for the regulatory exploration of developmental impact of potential toxic chemicals.