Integrative Health Sciences (IHS)

Leaders: Marc Schenker, Lars Berglund, Bill Lasley.

This core integrates the disciplines of human population studies (epidemiology), environmental exposure sampling and assessment, animal studies, biomedical/experimental/ clinical investigations and public health practice. The Core’s primary function is to facilitate interactions among all the other cores that comprise the Center for Environmental Health Sciences (CEHS), with an overall goal of translating basic environmental health science into practical tools for the detection, prevention and treatment of disease in clinical and community-based populations. Investigators: This Core brings together epidemiologists, Schenker, Gold, and Lasley, clinical investigators (Berglund), environmental epidemiologists (Hertz-Picciotto) and exposure assessment experts (Bennett). Their multidisciplinary, integrative research includes: respiratory and neurodevelopmental disease, cancer, and environmental effects on oxidative stress and endocrine-mediated disease. Specific human diseases and disorders are a target of much research within this core, reflecting the interaction of population scientists and clinical investigators working closely with basic scientists. Further, this research addresses health hazards from agrochemicals and related xenobiotics, and environmental contaminants, in many cases with particular attention to populations reflecting exposures at urban-agricultural interfaces.

 The specific aims of this Facility Core are to:

Provide information, facilities, staff and clinical expertise in order to conduct human population and clinical studies that will translate basic scientific findings into improved public health outcomes. Specifically:

(1) Identify and develop populations for sampling who have been exposed to neurodevelopmental, respiratory/cardiovascular or endocrinologic toxicants or carcinogens generated in the urban-agricultural interface in the Central Valley. Likewise to develop human populations affected with respiratory/cardiovascular, neurodevelopmental or endocrinologic conditions or cancer to identify environmental etiologic factors that are possibly related to these disorders;

(2) Collect environmental samples or biologic specimens to assess exposures by other Center investigators in an effort to assist with the characterization of toxicity mechanisms, exposures and/or adverse health effects;

(3) Coordinate the Facility Cores and so generate the appropriate data. These data will provide information on exposures, diseases and chemical/molecular profiles of biomarker expressions. Analysis of these data will lead to development of correlations of pollutant exposures or environmental contaminants with specific morbid conditions, and confirm or suggest hypotheses;

(4) Use the IHS data repository to aid formulation of plausible exposure–disease scenarios/hypotheses with the help of the Animal/Cell Models Facility Core or other relevant cores to delineate possible mechanisms by which toxic chemicals alter normal physiology of target organs leading to specific morbidities;

(5) Use IHS Core facilities and clinical expertise, to assist in construction of confirmatory studies. These studies will use clinical or community-based biological samples to conduct molecular epidemiologic studies with a goal of establishing cause-and-effect relationships between exposure and the target disease or disorder. In this way, the IHS Facility Core will be a conduit to clinical studies to validate and evaluate biomarkers of exposure and disease, and to initiate intervention or therapy for environmentally associated conditions;

(6) Serve as liaison for the Community Outreach and Education Core’s efforts to increase public awareness of environmental health factors and appropriate interventions to reduce risk from environmental toxicants.

The Integrated Health Sciences Core plays a central role in the UC Davis NIEHS Center.  This Core acts as the focal point for the translational activities planned by many of the Center’s investigators in the next 5 year period and serves as the primary mechanism by which Center investigators will be able to implement a more disease oriented approach in their work. The IHS Core will provide access that Center investigators will need to test hypotheses originally developed in animal models to obtain defined diseased/exposed and cohort populations to test their theories in humans.   

Analytical Core

Leader - Bruce Hammock

The Analytical Core provides modern analytical capability to Center investigators.  The Analytical Core is located in Everson Hall in the Central Campus and is divided into an instrumental laboratory and an immunochemical–biosensor laboratory. The Core assists Center laboratories with their analytical needs. This includes state of the art mass spectrometry equipment, but also more general analytical equipment for those laboratories lacking such equipment. The goal is to provide facilities and expertise to analyze small molecules largely by mass spectrometry and by immunoassay.  These techniques have and are being applied to human exposure to agricultural chemicals and other xenobiotics as well as pharmacokinetic evaluation and biomarker analysis.  Complementing the Genomics/Proteomics Core, the Analytical Facility Core provides instrumental and intellectual support for metabolomic characterization of biological systems.  Specifically this core provides expertise on chromatographic purification, identification and quantitative analysis of small molecules using a variety of techniques, development of antibodies and immunoassays to small haptens and proteins, high throughput analysis using immunoassay, and validation of immunoassays with mass spectral techniques. It also provides structural characterization of small organic metabolites using mass spectrometry, NMR spectroscopy and other techniques. It will continue focus on providing mass spectral support for small molecule analysis for metabolomics and for pharmacokinetics.  It provides the facilities for high throughput analysis of biofluids and environmental samples.

The Specific Aims of the Analytical Facility Core are to:

• Assist other investigators in the development and validation of new analytical methods emphasizing small molecules.
• Provide class specific and compound specific metabolomic support to integrate with transcriptomic and proteomic databases.  Both global fingerprinting and pathway specific profiling are supported.
• Provide facilities and technologies high throughput assays for environmental and human monitoring of agricultural chemicals, other xenobiotics, and biomarkers.
• Provide support for pharmacokinetic studies on small molecule environmental contaminants and chemical probes which alter xenobiotic metabolism.
• Afford access to the equipment and expertise necessary to conduct studies requiring the isolation, identification and quantitative measurement of small molecules.
• Provide a broad based analytical laboratory with walk up use of instrumentation to researchers in the center as well as expertise on generation and interpretation of analytical data.
• Provide hapten synthesis, conjugation, general infrastructure, equipment, and advice on the preparation of antibodies for immunoassay, histochemistry, Western blots and other uses.

ANIMAL MODELS

Leaders: Kent Lloyd and Dallas Hyde.

The aims of the Animal Models Core are to develop state-of-the-art experimental models available to Center members in four areas:

1)    Nonhuman primate models for reproductive and respiratory toxicology: Develop and maintain Web-based capability for sharing existing data and specimens; organize and compile data; coordinate access to new specimens as they are generated; store, catalog and ship specimens.

2)    Inhalation exposure models: Design, develop and validate inhalation exposure conditions for airborne pollutants (including reactive gases, pyrolysis products, bioaerosols, particulates, complex mixtures) and conduct and monitor test exposures for rodents and nonhuman primates, including primary nonhuman primate and human cells in culture.

3)    Transgenic mice for environmental toxicology: Develop, validate and establish transgenic mouse lines that allow testing of specific signaling and cytokine mechanisms.

4)    Cell models for toxicology studies: Develop, characterize and maintain a reservoir of primary nonhuman primate and human cells (i.e., tracheobronchial and alveolar cells), transfected human cell lines and monkey and human stem cells.  This approach will include transfection of stem cells with vectors for overexpression and gene silencing technologies for cells in vitro.  To develop and image injected stem cells (with or without gene transfection) in rodents and nonhuman primates using noninvasive imaging.

GENOMICS/PROTEOMICS

Leaders - Robert Rice and Jeffrey Gregg.

The overall goal of the Genomics and Proteomics Core is to assist in the identification of critical macromolecular differences (mRNA, protein) among cells or tissues from culture models, animal models or human studies that have or have not been exposed to toxic agents. Data collected using transcriptomic and proteomic analyses will be important for hypothesis generation and testing, biomarker development, and the elucidation of toxic mechanisms.  For example, cell culture studies can lead to hypotheses regarding the mechanisms by which specific targets are perturbed (points 10-12 in Figure 1) that can then be tested in animal studies (points 6-8), or findings in animals can be tested in culture.  Evidence for perturbation of macromolecular targets can then be pursued in human studies through utilization of associated biomarkers (point 2).  In the reverse direction, associations between environmental conditions and environmental outcomes may lead to identification of putative macromolecular biomarkers that can be examined in animal and culture models.  Anticipated findings of considerable value for establishing causation and for characterizing the degree of hazard are the dose or concentration dependence of effects and the relative sensitivity among species and model test subjects (organisms, tissues, cells).  This information will then facilitate clinical studies and permit scientifically defensible standards for exposure and for hazardous waste cleanup.  As seen in Figure 1, we envision an integrated approach to human, animal, in vitro and clinical studies.  Data generated through the Genomics/Proteomics Core is anticipated to help evaluate human effects through studies of biomarkers of exposure or effect and permit evaluation of potential sensitive populations, as well as to help in translation of mechanistic results from animal and in vitro to clinical studies.

 

During previous funding periods of the Center, transcriptome analysis was conducted in the Molecular Biology Facility Core, and proteomics was covered on a limited basis in the Analytical Biochemistry Facility Core.  Complementing the approach in the new Genomics and Proteomics Core, metabolomics efforts are being addressed in the new Analytical Facility Core (Core C).  Together, these efforts constitute a systems approach to analyzing effects of toxic agents. Through the Genomics and Proteomics Core, Center members will have opportunities to measure the effects of exposure at the levels of gene transcription and protein expression, a substantial advantage since any single method can analyze only part of the cellular response. In some cases, effects at one level may be dominant in driving the response, while in others more than one level is important in understanding the cell response.  Ultimately, integrating information from the various levels will permit fundamental mechanistic understanding of cellular effects from toxic perturbation. 

 The Specific Aims of the Genomics and Proteomics Core are to:

1.  Provide transcriptional profiling and confirmation through the use of:

A.  Commercial arrays such as Affymetrix chips

2.  Provide proteomic analysis including:

            A.  Protein identification

            B.  Quantitative protein profiling

      C.  Posttranslational modifications

3.   Provide appropriate in-depth training to graduate students, postdoctoral fellows, and technical staff.

4.   Develop new methods in transcriptomic/proteomic analysis to assist Center investigators in addressing research questions in their laboratories.

5.   Assist investigators in obtaining preliminary data and providing methodological support for new grant applications.

 IMAGING

Leaders - Kent Pinkerton and Laura Van Winkle

The overall goal of the Imaging Facility Core (IFC) is to assist in the identification of toxic responses among cells or tissues from animal models, culture models or human studies using histologic approaches and imaging.  The IFC has served the Center since its inception as a resource for scientists, investigators, faculty, fellows and students with a wide variety of backgrounds, some of whom are completely unfamiliar with imaging or sample preparation options. The Imaging Facility Core has continuously offered cutting-edge guidance on experimental design, training, services and equipment use, while providing expertise and analytical capabilities in transmission and scanning electron microscopy, microtomy, sample dissection, immunohistochemistry, in situ hybridization and tissue fixation/processing.  

1.  Provide service in microscopy and imaging to all investigators, including:

A.  Tissue sampling and specimen preparation;

B.  Microscopic image acquisition ;

C.  mRNA and protein detection in/from specimens;

D.  Quantitative and qualitative imaging of cells, sectioned tissue and whole mounts;

E.  Analysis of digital 2-D, 3-D, 4-D, and 5-D images;

F.  Live cell imaging;

      G.  Image adjustment, rendering, qualitative analysis and presentation; and

      H.  Image and text database development, data archiving and retrieval.

 

2.  Provide appropriate in-depth training to graduate students, postdoctoral fellows and technical staff, including:

      A.  Tissue preparation and microtomy for light, epifluorescent and electron microscopy;

      B.  Confocal laser scanning microscopy;

      C.  Laser capture imaging and microdissection; 

      D.  Cellular imaging with quantitative ion analysis;          

      E.  Histopathology and Immunocytochemistry (ICC) staining and trouble shooting;

      F.   In situ hybridization (ISH); and          

      G.  Videomicrometry.   

 

3.  Act as a resource and referral service by providing information on the latest imaging approaches        and techniques, including those not available in the Core but present in other facilities at UC Davis.

 

4. Assist in the development of new methodologies in imaging to assist Center investigators in       addressing research questions in their laboratories.

 

5. Assist investigators in obtaining preliminary data and providing methodologic support for new       grant applications.

 

The Facility Core faculty and staff are available for consultations on development of new methodologies or approaches in all aspects of the imaging techniques described above.  IFC staff and faculty provide a technical reference resource, as well a scientific explanation of new technologies not present in this Core but available through other UC Davis facilities.  An example of such consultation is the most efficient methods for tissue preservation and sectioning to collect tissues for microarray analysis.  These methods also extend to the vascular perfusion preparations to insure blood-free organs for tissue proteomics and metabolomic procedures. The Facility Core and staff are also actively involved in teaching courses and workshops at both UC Davis and at conferences/society meetings on topics in microscopy, stereology, fluorescence microscopy and preparation/analysis of three-dimensional tissue samples.  The primary goals of this facility core continue to be: (1) provide service in imaging to scientists, faculty and students affiliated with the Center; (2) act as a resource and referral service by providing information on the latest imaging approaches and techniques; and (3) offer training to graduate students, postdoctoral fellows and junior scientists in the use of imaging equipment.

 

The IFC has a long history of providing access to equipment, training, services and consulting expertise related to the analysis of normal and abnormal morphology at the whole animal, organ, cell, subcellular, and molecular levels, which forms an integrated approach to human, animal, in vitro and clinical studies, as illustrated in Figure 4. An ongoing mission of this Facility Core is to provide the most updated, state-of-the-art techniques and services to all investigators, both in and out of CEHS, interested in using imaging in their research.

Research Cores

Overview and Significance. Agriculture in California’s Central Valley is highly varied.  Rich soil combined with abundant sunlight is ideal for crops as varied as walnuts, almonds, citrus, cotton, rice, and tomatoes.  Pesticides and agricultural dusts, exacerbated by the arid climate, are potentially important toxic byproducts of these agricultural activities.  What is less obvious are sources of environmental pollution from unregulated diesel and gasoline engines that are used to pump water and produce power for plowing and  harvesting operations.  Large commercial dairy, beef, and poultry operations add to the potential mixture of pollutants released into the environment.  In addition, the degradation of the air quality in the Central Valley has been exacerbated by explosive population growth in cities such as Sacramento, Tracy, and Stockton, which are now serving as bedroom communities for commuters to the Bay Area.  Intense sunlight, with temperatures in the summer often exceeding 100°F, combined with emissions associated with fossil fuel combustion resulting from gridlock on freeways in the Central Valley means that the population is exposed to known hazards (oxidants, particles) and to a number of other compounds whose toxicity in animals is well delineated but for which the health effects in humans are largely unknown.  More importantly we understand very little about how the mixture of potential toxicants acts in a synergistic or antagonistic fashion to result in long term deleterious effects on pulmonary, cardiovascular, and renal function.  Prospective studies conducted over the long term in Southern California have shown that certain air pollutants (e.g. NO₂, <2.5 µ particles) alter the development of the lung, resulting in decrements in forced expiratory volume (FEV₁) (Gauderman et al., 2004).  Not clear are whether these decrements eventually resolve, whether they lead to long-term disease processes, what the specific impacts of each of the individual components of polluted air contribute to overall disease, and how these components interact.