Understanding the interaction between maternal tobacco use during pregnancy and adult offspring with conduct disorder

Alexandra Noble,1 John Pearson,2 Joseph Boden,3 John Horwood,3 Martin Kennedy,2 Amy Osborne1

1Biological Sciences, University of Canterbury, Christchurch, New Zealand;2Department of Pathology and Biomedical Sciences, University of Otago, Christchurch, New Zealand; 3Department of Psychological Medicine, University of Otago, Christchurch, New Zealand.

Aims

Metastable epialleles (MEs) are described as loci at which epigenetic regulation is established during in utero development and maintained throughout life. We know that maternal tobacco smoking during pregnancy can alter offspring DNA methylation. Furthermore, associations between maternal smoking and offspring conduct disorder has been observed. Our aim is to provide a molecular link between maternal smoking and conduct disorder in offspring.

Methods

Both exposed to maternal tobacco smoking in utero and individuals who were not were selected from the Christchurch Health and Development longitudinal study. This also included groups of individuals with and without conduct disorder. Bisulfite-based Amplicon Sequencing (BSAS) was used to investigate DNA methylation differences and potential MEs between the different groups.

Results

A novel gene, GRIN2b, which is expressed during in utero development and declines post birth, displays differential DNA methylation in response to maternal tobacco exposure in offspring adults with conduct disorder.

Conclusions

This research shows DNA methylation providing an aetiology of the observed link between maternal smoking and childhood/adolescent conduct disorder, which provides new insights into the mechanisms involved in the detrimental outcomes associated with in utero tobacco smoke exposure.

An exploratory patient study assessing CYP450 enzyme function in women receiving chemotherapy for breast cancer

Rebekah Crake,1 Matthew Strother,1,2 Helen Morrin,1,3 Anne Smith,2 Elisabeth Phillips,1 Bridget Robinson,1,2 Margaret Currie1

1Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand; 2Canterbury Regional Cancer & Haematology Service CDHB, Christchurch, New Zealand; 3Cancer Society Tissue Bank Christchurch, Christchurch, New Zealand.

Aims

Obese breast cancer patients respond less well to chemotherapy. Chemotherapy drugs are metabolised by cytochrome P450 (CYP450) enzymes. Inflammatory cytokines inhibit expression and activity of CYP450 enzymes, altering drug metabolism. This study (HDEC:16/CEN/116) investigated whether obesity-related cytokines are associated with alterations in CYP450 activity in women receiving chemotherapy for breast cancer.

Methods

Phenotypic activity of CYP450 enzymes (CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A4) were assessed using the ‘Inje’ probe drug cocktail and mass spectrometry. Inflammatory cytokines were quantified in patient serum samples using immunoassays. Voluntary physical activity was recorded on FitBit One® devices.

Results

This study recruited 12 women (n=7, BMI<30; n=5, BMI≥30), aged 40–68 years. Serum B-cell activating factor (BAFF), growth and differentiation factor 15 (GDF-15) and monocyte chemoattractant protein 1 (MCP-1) increased, and interleukin 10 (IL-10) decreased during chemotherapy. As serum concentrations of MCP-1 increased, the activity of CYP3A4 decreased. Daily step counts decreased early in chemotherapy. However, alterations in cytokine concentrations were not dependent on differences in obesity or physical activity.

Conclusions

This study provides preliminary evidence that circulating inflammatory cytokines may influence CYP450-mediated chemotherapy metabolism, and validates feasibility of the ‘Inje’ cocktail to measure CYP450 activity in patients receiving chemotherapy for breast cancer.

Variable expression quantitative trait loci analysis of breast cancer risk variants

George Wiggins,1 John Pearson,1,2 Mik Black,3 Anita Dunbier,3 Tony Merriman,3 Logan Walker1

1Department of Pathology and Biomedical Science, University of Otago Christchurch, NZ; 2Biostatistics and Computational Biology Unit, University of Otago Christchurch, NZ; 3Department of Biochemistry, University of Otago, Dunedin, NZ.

Aim

Genome wide association studies in breast cancer have identified more than 180 risk variants. A major challenge has been to understand the functional consequences of these variants. Studies to date have utilised expression quantitative trait loci (eQTL) to identify candidate susceptibility genes at risk loci. We propose that variable expression quantitative trait loci (veQTL) will provide additional information and identify novel candidate breast cancer susceptibility genes.

Methods

RNA-sequencing and genotype data from 635 samples was acquired from the Genotype-Tissue Expression (GTEx) Common Fund Project. Tissue-specific veQTL and eQTL analysis was performed using breast cancer risk variants from four tissue types: breast, kidney, lung and ovary.

Results

Seventy veQTL identified 60 candidate genes associated with breast cancer risk variants in breast tissue. These were enriched for genes involved in C21-steroid biosynthesis and extracellular structure process. Notably, individuals homozygous for the risk allele of rs11075995 were associated with expression variability of four genes (STAR, CYP17A1, CYP11B1 and HSD3B2) involved in the conversion of cholesterol into steroids, a potential mechanism of cancer risk.

Conclusion

Tissue-specific veQTL analysis identified novel candidate breast cancer susceptibility genes, including those associated with the C21-steroid biosynthesis pathway.

Ocular gene therapy protects against retinal degeneration and vision loss in sheep with CLN5 Batten disease

Murray SJ,1 Russell KR,1 Gray SJ,2 Palmer DN,1 Mitchell NL1,3

1Faculty of Agricultural and Life Sciences, Lincoln University, Lincoln 7647, New Zealand; 2University of Texas Southwestern Medical Center, Dallas, Texas, USA; 3Department of Radiology, University of Otago, Christchurch 8140, New Zealand.

Aims

To test if ocular gene therapy can preserve retinal structure and function. Neuronal ceroid lipofuscinoses (NCL; Batten disease) are a group of inherited neurodegenerative diseases primarily affecting children. A common feature is progressive loss of vision. Brain-directed gene therapy in sheep models of CLN5 and CLN6 NCL can halt disease progression, however treated animals still lose their sight.

Methods

We performed intravitreal injections of self-complementary AAV9 vectors containing either CLN5 or CLN6 into three-month-old CLN5-/- or CLN6-/- sheep. Electroretinography (ERG) was performed monthly following treatment and retinal histology was assessed post-mortem.

Results

ERG b-wave amplitudes were normalised in the treated eyes compared with the untreated eyes in CLN5-/- animals up to 18 months of age. ERG amplitudes in both eyes of CLN6-/- animals declined with age, however the treated eye maintained higher amplitudes. Post-mortem analyses revealed significant attenuation of retinal atrophy and storage body accumulation in the treated eye compared with the untreated eye in both CLN5-/- and CLN6-/- animals.

Conclusions

The single administration of AAV9.CLN5 can successfully ameliorate retinal deficits in CLN5-/- sheep. Therefore combining ocular and brain-directed gene therapies presents a promising treatment strategy for future trials aiming to halt clinical progression in CLN5 NCL.

Circulating myeloperoxidase is elevated in septic shock and is associated with systemic organ failure and mortality in critically ill patients

Emma Spencer,1 Teagan Hoskin,2 Patrice Rosengrave,1 Anthony Kettle,2 Geoffrey Shaw,3 Anitra Carr1

1Nutrition in Medicine Research Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch; 2Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch; 3Department of Intensive Care, Christchurch Hospital, Christchurch, New Zealand.

Aims

This study aimed to determine if the oxidant-generating enzyme myeloperoxidase is elevated in critically ill patients and if elevated levels are associated with adverse patient outcomes.

Methods

Myeloperoxidase was measured by ELISA in a cohort of 44 critically ill patients and 44 healthy controls. Intensive care mortality prediction scores (SOFA, APACHE III) and patient mortality were obtained from clinical notes. Routine blood measures of organ dysfunction were assessed and cell-free DNA was detected using fluorescence staining.

Results

Myeloperoxidase was significantly higher in critically ill patients than healthy controls, and was elevated in septic shock relative to non-septic patients. Myeloperoxidase correlated significantly with SOFA scores in the critically ill patients, and with markers of tissue dysfunction and injury such as lactate, alanine transferase and cell-free DNA. Hospital mortality for the whole cohort was 27%; mortality in the high APACHE III subgroup was 38%, and when combined with higher than mean myeloperoxidase, mortality increased to 71%.

Conclusions

Myeloperoxidase is associated with markers of tissue injury and systemic organ failure, particularly in septic patients. The enzyme is also associated with mortality in patients with higher APACHE III scores, and thus has potential as a diagnostic marker to improve mortality prediction.

Examining the links between community water fluoridation, area-level deprivation and childhood dental ambulatory sensitive hospitalisations: nationwide pooled evidence from New Zealand

Hobbs M,1 Wade A,2 Marek L,1 Tomintz M,1 Jones P,3 Sharma K,3 McCarthy J,3 Mattingley B,4 Campbell M,1 Kingham S1

1GeoHealth Laboratory, Geospatial Research Institute, University of Canterbury, New Zealand; 2Registered Dentist, New Zealand; 3Ministry of Health, Wellington, New Zealand; 4Institute of Environmental Science and Research Limited (ESR).

Aim

This study examines the association between community water fluoridation (CWF) and dental ambulatory sensitive hospitalisations (ASH) and the moderating effect of CWF on the association between area-level deprivation and dental ASH.

Method

Dental ASH conditions, ie, dental caries and diseases of pulp/periapical tissues, age, gender and meshblock were extracted from pooled (2011 to 2017) cross-sectional data on children aged 0–4 and 5–12 from the National Minimum Dataset. Dental ASH rates for children aged 0–4 and 5–12 (/1,000) were calculated for census area units (CAU). CWF was obtained for 2011 and 2016 from the Institute of Environmental Science and Research. Multilevel negative binomial models investigated associations between area-level deprivation, dental ASH rate, and moderation by CWF status.

Result

Findings show that relative to CWF in both 2011 and 2016, no CWF was associated with increased dental ASH rates in children aged 0–4 (IRR=1.17 [1.06–1.29]; and aged 5–12 (IRR=1.18 [1.08–1.29]). The association between CWF and dental ASH rates was more pronounced for children within the most deprived areas in children aged 0–4.

Conclusion

Our findings suggest that variation in CWF is associated with structural inequalities in oral health outcomes for children in New Zealand.