Macquarie Group Foundation Chair of Schizophrenia Research, based at NeuRA and UNSW
Professor, School of Psychiatry, UNSW
+612 9399 1717
Cyndi’s research is focused on the molecular developmental neurobiology of schizophrenia. She earned a PhD in Biomedical Science at Mount Sinai School of Medicine, New York City and completed postdoctoral training at the National Institute of Mental Health rising to the level of Unit Chief of Molecules in the Neurobiology and Development of Schizophrenia Unit. Her awards include the Eli Lilly Young Investigator Award, NIH Fellows Award for Research Excellence, Independent Investigator Award and two Young Investigator Awards from NARSD. She has lectured throughout the world and contributed to over 150 publications.
Studying the molecular basis of raloxifene (a SERM) modulation of dopamine signalling in schizophrenia, which uses a maternal immune activation rodent model of schizophrenia to better understand how raloxifene brings about its effects.
Together with Professor Peter Schofield (NeuRA) and Professor Philip Mitchell (Black Dog Institute), our group is investigating the genetic contributors to bipolar disorder using Australian families with multiple individuals who have been diagnosed with the disorder.
The group previously identified a bipolar susceptibility locus located on chromosome 15 in a pooled analysis of 35 families. More detailed analysis of this region has identified a single gene, which confers an increased susceptibility to both bipolar disorder and schizophrenia, and has also been implicated as a risk factor for autism.
The group is now aiming to understand how alterations in ST8SIA2 translate into an increased genetic susceptibility by characterising alterations in the DNA, RNA and protein product of this gene and its interaction partners in patients with either bipolar disorder or schizophrenia.
DR DUNCAN SINCLAIR Postdoctoral Fellow
DEBORA ROTHMOND Senior Research Assistant
DANNY BOERRIGTER Research assistant
ROXANNE CADIZ Technical assistant
YIRU ZHANG PhD student
KATE NAUDE Research assistant
Many genes are differentially expressed in the cortex of people with schizophrenia, implicating factors that control transcription more generally. Hormone nuclear receptors dimerize to coordinate context-dependent changes in gene expression. We hypothesized that members of two families of nuclear receptors (NR4As), and retinoid receptors (RARs and RXRs), are altered in the dorsal lateral prefrontal cortex (DLPFC) of people with schizophrenia. We used next generation sequencing and then qPCR analysis to test for changes in mRNA levels for transcripts encoding nuclear receptors: orphan nuclear receptors (3 in the NR4A, 3 in the RAR, 3 in the RXR families and KLF4) in total RNA extracted from the DLPFC from people with schizophrenia compared to controls (n = 74). We also correlated mRNA levels with demographic factors and with estimates of antipsychotic drug exposure (schizophrenia group only). We tested for correlations between levels of transcription factor family members and levels of genes putatively regulated by these transcription factors. We found significantly down regulated expression of NR4A1 (Nurr 77) and KLF4 mRNAs in people with schizophrenia compared to controls, by both NGS and qPCR (p = or <0.01). We also detected decreases in NR4A2 (Nurr1) and RXRB mRNAs by using qPCR in the larger cohort (p<0.05 and p<0.01, respectively). We detected decreased expression of RARG and NR4A2 mRNAs in females with schizophrenia (p<0.05). The mRNA levels of NR4A1, NR4A2 and NR4A3 were all negative correlated with lifetime estimates of antipsychotic exposure. These novel findings, which may be influenced by antipsychotic drug exposure, implicate the orphan and retinoid nuclear receptors in the cortical pathology found in schizophrenia. Genes down stream of these receptors can be dysregulated as well, but the direction of change is not immediately predictable based on the putative transcription factor changes.
In order to conduct postmortem human brain research into the neuropatho-logical basis of schizophrenia, it is critical to establish cohorts that are well-characterized and well-matched. The aim of the present study was therefore to determine if specimen characteristics including: diagnosis, age, postmortem interval (PMI), brain acidity (pH), and/or the agonal state of the subject at death related to RNA quality, and to determine the most appropriate reference gene mRNAs. In the present cohort <10% variability in RINs was detected and the diagnostic groups were well matched overall. The cohort was adequately powered (0.80-0.90) to detect mRNA differences (25%) due to disease. The study suggests that multiple factors should be considered in mRNA expression studies of human brain tissues. When schizophrenia cases are adequately matched to control cases subtle differences in gene expression can be reliably detected.
Stress has been implicated in the onset and illness course of schizophrenia and bipolar disorder. The effects of stress in these disorders may be mediated by abnormalities of the hypothalamic-pituitary-adrenal axis, and its corticosteroid receptors. We investigated mRNA expression of the glucocorticoid receptor (GR) and mineralocorticoid receptor (MR), and protein expression of multiple GRα isoforms, in the prefrontal cortex of 37 schizophrenia cases and 37 matched controls. Quantitative real-time PCR, western blotting, and luciferase assays were employed. In multiple regression analysis, schizophrenia diagnosis was a significant predictor of total GR mRNA expression (p<0.05), which was decreased (11.4%) in schizophrenia cases relative to controls. No significant effect of diagnosis on MR mRNA was detected. At the protein level, no significant predictors of total GRα protein or the full-length GRα isoform were identified. However, schizophrenia diagnosis was a strong predictor (p<0.0005) of the abundance of a truncated ≈ 50 kDa GRα protein isoform, putative GRα-D1, which was increased in schizophrenia cases (80.4%) relative to controls. This finding was replicated in a second cohort of 35 schizophrenia cases, 34 bipolar disorder cases, and 35 controls, in which both schizophrenia and bipolar disorder diagnoses were significant predictors of putative GRα-D1 abundance (p<0.05 and p=0.005, respectively). Full-length GRα was increased in bipolar disorder relative to schizophrenia cases. Luciferase assays demonstrated that the GRα-D1 isoform can activate transcription at glucocorticoid response elements. These findings confirm total GR mRNA reductions in schizophrenia and provide the first evidence of GR protein isoform abnormalities in schizophrenia and bipolar disorder.