Genome Editing Research for Translational Toxicology Solutions

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Program Director, Graduate Studies, Curriculum in Toxicology, UNC Chapel Hill Department of

1 Genome Editing Research for Translational Toxicology Solutions REBECCA FRY, PH.D. Carol Remmer Angle Distinguished Professor and Associate Chair Director, UNC Superfund Research Program Director, Graduate Studies, Curriculum in Toxicology, UNC Chapel Hill Department of Environmental Sciences and Engineering Gillings School of Global Public Health, UNC-Chapel Hill Lineberger Comprehensive Cancer Center

Confirm mechanisms of environment-pathway-disease relationships relevant for human populations

2 Potential uses of genome editing in environmental health Cell culture/model systems Identify biological mechanism of action of environmental contaminants Epidemiology-based research Confirm mechanisms of environment-pathway-disease relationships relevant for human populations and move from association to causation Risk assessment Develop and optimize Adverse Outcome Pathways (AOPs)

3 Understanding the impact of environmental exposures during pregnancy on the health of women and children

4 Applying genome editing to cell culture and model systems for environmental health research Model organisms for developmental toxicity In vitro-based assessment using placental trophoblast cells (JEG) Can we identify biological mechanism of action of environmental contaminants?

5 Applying genome editing to cell culture and model systems for environmental health research Model organisms for developmental toxicity In vitro-based assessment using placental trophoblast cells (JEG) Can we identify biological mechanism of action of environmental contaminants?

6 Inorganic arsenic continues to poison individuals around the globe North Carolina Classified as Group 1 Carcinogen by the International Agency for Research on Cancer (IARC): Chronic exposure results in many cancers: skin, bladder, lung, liver, prostate and kidney N=>2 million Up to 800 ppb What are the critical underlying biological pathways linking arsenic to developmental defects?

7 Inorganic arsenic continues to poison individuals around the globe North Carolina Classified as Group 1 Carcinogen by the International Agency for Research on Cancer (IARC): Chronic exposure results in many cancers: skin, bladder, lung, liver, prostate and kidney N=>2 million Up to 800 ppb Exposure is associated with noncancer endpoints: neurological disorders, reproductive effects, cardiovascular disease, diabetes, birth defects What are the critical underlying biological pathways linking arsenic to developmental defects?

Toxicological research to identify biological

disease Genes and biological pathways control

narrow the potential genes and associated

8 Toxicological research to identify biological pathways underlying contaminant-induced disease Genes and biological pathways control +arsenic Systems biology-based approach to narrow the potential genes and associated pathways linking ias to birth defects Birth defects head fold region, microcephaly, anterior neural tube defects, and gross facial deformities Ahir et al, 2013

9 Low doses of arsenic increase GR activity Higher doses decrease GR activity Ahir et al, 2013

10 Low doses of arsenic increase GR activity Higher doses decrease GR activity X Does the GR pathway mediate arsenic-induced birth defects? Ahir et al, 2013

11 Pathway blockade prevents arsenic-induced disease Control Arsenic -exposed Use in ovo whole chick embryo culture and block GR signaling Ahir et al, 2013

12 Pathway blockade prevents arsenic-induced disease Control Arsenic -exposed Arsenic exposed + chemical inhibitor GR Use in ovo whole chick embryo culture and block GR signaling Ahir et al, 2013

13 Pathway blockade prevents arsenic-induced disease Arsenic exposed + Control Role of genome-editing Arsenic -exposed in chemical EHS inhibitor GR Confirm genes and proteins within biological pathways critical for disease Ahir et al, 2013

environment-pathway-disease relationships relevant for

14 Genome editing applied to epidemiology-based research in environmental health Can we confirm mechanisms of environment-pathway-disease relationships relevant for human populations and move from association to causation?

after the 20 th week of gestation in a previously normotensive woman Delivery remains only cure, usually

15 Epidemiologic studies support that cadmium is associated with the pregnancy complication preeclampsia Leading cause of poor fetal outcomes Affects up to 10% of pregnancies worldwide Hypertension, proteinuria after the 20 th week of gestation in a previously normotensive woman Delivery remains only cure, usually results in preterm delivery: placenta is required for disease Suspected to involve failed trophoblast invasion

16 Placental cadmium is associated with preeclampsia risk in a US pregnancy cohort OR of PE: 1.5 (CI ) Case-Control Study: US-based: NC, Alabama, TX Laine et al PLOSOne

17 Cadmium-associated preeclampsia hypothesized to be linked to failed trophoblast invasion

18 Cadmium-associated preeclampsia hypothesized to be linked to failed trophoblast invasion Which genes/pathways mediate cadmium-induced preeclampsia?

19 The TGF-β pathway has been associated with PE

20 The TGF-β pathway has been associated with PE

21 The TGF-β pathway has been associated with PE Does the TGF-B pathway mediate cadmium-induced preeclampsia?

Blocking TGF-β pathway mitigates the effects of Cd on trophoblast migration Placental cells % Migration (versus control) 175 150 125 100 75 50 25 *** *** TGFβ1 Only TGFβ1 + 0.

22 Blocking TGF-β pathway mitigates the effects of Cd on trophoblast migration Placental cells % Migration (versus control) *** *** TGFβ1 Only TGFβ uM CdCl 2 *** * TGFBR Inhibitor Only ** TGFBR Inhibitor uM CdCl 2 p<0.05 * p<0.01 ** p<0.001 *** Inhibit the pathway, and cadmium-induced effects on migration are minimized

23 Genome editing in translational research for environmental health Role of genome-editing in EHS 1. Confirm genes and proteins within biological pathways critical for disease 2. Prevent contaminant-induced disease through pathway blockade

24 Potential uses of genome editing in the risk assessment process Can we develop and optimize Adverse Outcome Pathways (AOPs)?

25 Decades of research support a suite of mechanisms that underlie toxicity Cellular and molecular machinery Biomarkers: Epigenetic, Genomic, Proteomic, Metabolomic, Inflammatory responses, Michael Hughes, et al Tox Sci 132(2) (2011)

26 Scientific gaps remain. Cellular and molecular machinery Which of these mechanisms is relevant to developmental toxicity? What is the biological chain of events linking arsenic to developmental toxicity? Biomarkers: Epigenetic, Genomic, Proteomic, Metabolomic, Inflammatory responses, Michael Hughes, et al Tox Sci 132(2) (2011)

27 Filling these gaps using an Adverse Outcome Pathway (AOP) framework Conceptual construct that portrays existing knowledge concerning the linkage between a direct molecular initiating event and an adverse outcome. Ankley, 2010 Volume 29, Issue 3; March 2010; Pages

Adverse Outcome Pathways (AOPs) for fetal outcomes in relation to arsenic Molecular Cell Tissue/Organ Organism Population Reactive Oxygen Species Increased production Depletion of antioxidant

cells Altered development and function 1 4 Maternal/ fetal lower birth weight/growt h restriction 15 Population Shift in population distribution of infant birth weight SAM modification Transcription

28 Adverse Outcome Pathways (AOPs) for fetal outcomes in relation to arsenic Molecular Cell Tissue/Organ Organism Population Reactive Oxygen Species Increased production Depletion of antioxidant defenses 2 1 Oxidative stress Placental/fetal cells Altered gene expression, growth related genes and pathways (KCNQ1, NF-KB, TNF, GCR) Altered cell growth and function 1 2 Placenta/fetal cells Altered development and function 1 4 Maternal/ fetal lower birth weight/growt h restriction 15 Population Shift in population distribution of infant birth weight SAM modification Transcription factor modification 4 5 Epigenetic alterations (DNA methylation, mirnas) Immune cells Increased gene expression, inflammatory mediators (cytokines and chemokines) 1 3 Molecular Initiating events (MIE) Key molecular effects Adverse Outcome o Describe a sequential chain of causally-linked events at different levels of biological organization. o Detail the linkage between a direct/key molecular initiating event and the adverse outcome. Steve Edwards, Cataia Ives EPA o Mechanistic reasoning is essential to support chemical risk assessment.

Establishing key mechanistic relationships necessary for Adverse Outcome Pathway

29 Potential uses of genome editing in environmental health science Confirm functional role genes and proteins within biological pathways as mediators of disease Establishing key mechanistic relationships necessary for Adverse Outcome Pathway development (key to risk assessment process) Prevent contaminant-induced disease through pathway blockade

30 Funding NIEHS Superfund: P42 ES NIEHS (ONES): R01ES NIEHS CEHS UNC: P30ES Acknowledgements

Placental steroid receptors and sex differences in fetal growth

Placental steroid receptors and sex differences in fetal growth Professor Vicki Clifton Mater Medical Research Institute University of Queensland Brisbane, Australia Sex differences start in utero Lying-in