title: Effects of lithium and valproic acid on gene expression and phenotypic markers in an NT2 neurosphere model of neural development.
abstract: 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.
authors.affiliation: Aston Research Centre for Healthy Ageing, School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, United Kingdom. hillej@aston.ac.uk
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Hill
authors.forename: David A
authors.initials: DA
authors.lastname: Nagel
authors.forename: John D
authors.initials: JD
authors.lastname: O'Neil
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Torr
authors.forename: Elizabeth K
authors.initials: EK
authors.lastname: Woehrling
authors.forename: Andrew
authors.initials: A
authors.lastname: Devitt
authors.forename: Michael D
authors.initials: MD
authors.lastname: Coleman
mesh_terms: D018929:Cell Culture Techniques; D002453:Cell Cycle / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D018021:Lithium Chloride / Q000494:pharmacology*; D058977:Molecular Sequence Annotation; D055495:Neurogenesis / Q000187:drug effects*; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D015203:Reproducibility of Results; D055746:Stage-Specific Embryonic Antigens / Q000235:genetics / Q000378:metabolism; D014635:Valproic Acid / Q000494:pharmacology*
chemical_list: D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; D055746:Stage-Specific Embryonic Antigens; C066584:stage-specific embryonic antigen-4; D014635:Valproic Acid; D018021:Lithium Chloride