James E. Klaunig - US grants

oxidative stress; oxidation; nutrient intake activity; tea; diet; DNA damage; free radicals; antioxidants; clinical research; human subject; alternative medicine; nutrition related tag;

smoking; salicylate; tobacco abuse; free radicals; diagnosis design /evaluation; method development; clinical research; human subject;

This is an intervention human trial to study the protective effect of green tea on oxidative stress induced by cigarette smoking. Oxidative biomarkers, including oxidative end products, antioxidants and free radicals, will be measured to evaluate the effect. Inter and Intra individual variation of each biomarker will be addressed.

DESCRIPTION (provided by applicant): Liver cancer currently ranks fifth highest of all human cancers in incidence and third highest in cancer mortality. Recent investigations have reported a dramatic increase in the incidence of the liver cancer in the US. The etiology of human liver cancer has been linked to a number of factors including hepatitis B and C infection, mycotoxin exposure, iron overload, and environmental agents. Chronic liver hyperplasia is a common feature in human liver neoplasia development and as such appears to follow the same sequential multi-step process seen in rodent liver. While the hepatocyte is the target of most liver carcinogens, recent evidence suggests that non-parenchymal cells, including the Kupffer cell (the resident liver macrophage), may be an important component of growth regulation in the liver. The Kupffer cell upon activation can produce an array of products, including reactive oxygen intermediates and cytokines, which may impact on cell growth regulation. Little is known about the role of the Kupffer cell in hepatocarcinogenesis. The long term objectives of these studies therefore are to better understand the role that the Kupffer cell plays in this process. The proposed studies will specifically examine whether activation of the Kupffer cell is important in the tumor promotion stage of hepatic tumorigenesis. The overall hypothesis of these studies is that activation of Kupffer cells result in the release of cellular growth regulatory signaling molecules that selectively produce an increase in cell proliferation in initiated cells ultimately leading to hepatic neoplasia. These studies will examine the effect of Kupffer cell activation and deactivation on both normal (noninitiated) and initiated hepatocyte growth, and will determine whether activation hepatic tumor promoting compounds activate Kupffer cells, which result in hepatocyte proliferation. The products of the tumor promoter activated Kupffer cells will be determined and examined for potential hepatocyte growth regulatory effects. In addition, the effect of Kupffer activation, either by LPS (lipopolysaccharide) or hepatic tumors promoters on preneoplastic lesion growth and normal liver growth will be investigated These studies will provide information regarding the interplay between the Kupffer cell and heptatocytes during the tumor promotion stage of hepatocarcinogenesis. These studies will further our understanding into the mechanisms of the development and progression of human liver cancer with potential application to prevention and therapy.

DESCRIPTION (provided by applicant): Pharmacological and toxicological processes occur across a wide range of spatial and temporal scales and include multiple organ systems. A Systems Biology in silico toxicological model must include submodels that cover the multiple scales and the multiple tissues relevant to human medicine and toxicology. We will develop a liver centered mechanism based multiscale in silico simulation framework for xenobiotic toxicity and metabolism that incorporates four key biological scales: Population genetic and exposure variation scale Physiologically Based Pharmacokinetic (PBPK) whole body scale Tissue level and multicellular scale Subcellular signaling and metabolic pathways scales The multiscale in silico simulation will be centered on the liver, a critical organ in many toxicological, pharmacological, normal and disease processes. For our initial simulations of toxic challenge to the liver we will build a mechanism based in silico simulation of Acetaminophen (APAP) toxicity. APAP is a widely used over-the-counter pain reliever and fever reducer. An acute overdose of APAP is a leading cause of liver failure in the western world. APAP overdose leads to centrilobular liver necrosis that can progress to liver failure and in some cases patient death. Our multiscale in silico simulation will link existing open source modeling tools for the various spatiotemporal scales into an aggregate in silico model. This approach allows us to leverage existing tools, modeling modalities and models at the individual biological scales. Furthermore, this approach facilitates swapping models at individual scales without extensive modification of the sub-models at the other scales and allows us to leverage existing model development tools and resources. The complete multiscale in silico model will provide a mechanism based framework that incorporates effects at the various scales and will also provide a framework to predict changes in clinically used serum markers of liver function and failure. Our in silico simulation will be calibrated using microscopic imaging in the liver of a living mouse, mouse liver immune-histology, along with standard histology and serology in animal studies of APAP toxicity. The proposed in silico model is a first step in toxicity prediction 1. 2. 3. 4. simulatio that ultimately will lead to improved techniques for prediction toxicity of therapeutic agents and environmental toxins while simultaneously reducing the need for animal toxicity studies.