45 research outputs found
Effects of lithium and valproic acid on gene expression and phenotypic markers in an NT2 neurosphere model of neural development
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
Small Chromosomal Integration Site of Classical CTX Prophage in Mozambique Vibrio Cholerae O1 Biotype El Tor Strain
An unusual strain of Vibrio cholerae O1 biotype
El Tor harbouring multiple tandem copies of classical
CTX prophage caused a cholera epidemic in Mozambique
in 2004. However, the location of the classical CTX prophage
in the genome of the Mozambique strain was
unknown. In this study, pulsed Weld gel electrophoresis
(PFGE) of the whole genome along with Southern hybridization
experiments indicated that the classical CTX prophage
present in the Mozambique strain is located in the
small chromosome. To determine the CTX prophage integration
site in the small chromosome of Mozambique
strain, the 5_and 3_ junctions of the prophage and small
chromosome were PCR ampliWed, cloned and sequenced.
Sequence analysis indicated that the prophage was integrated
in the conserved dif site of the replication terminus
region of the Mozambique strain. While using an O1 El Tor
isolate VC44 as a control strain, which carries tandem copies
of CTX prophage in its small chromosome like the
Mozambique strain, it was unexpectedly detected that the
strain VC44 also possesses classical cholera toxin B gene
allele. Since the strain VC44 was isolated in India in the
year 1992, it appears that the Mozambique strain has probably
originated from a VC44-like strain