The Mass Spectrometry Core identifies and quantifies proteins that change expression in well-characterized protein fractions from cancerous cells or tissues. This includes identifying and quantifying changes in binding partners and post-translational modifications. Column chromatography and gel electrophoresis-based one and two-dimensional separations of protein complexes coupled to mass spectrometry are used. Techniques such as difference gel electrophoresis (DIGE), isobaric tag for relative and absolute quantitation (iTRAQ) and 18O-labeling as well as non-labeling methods (MudPit, multi-dimensional protein identification technology) are available for quantifying relative differences in protein expression and post-translational modifications. We developed methods to detect post-translational modifications such as LCMS methods to accurately determine the intact mass of proteins, selective fluorescent labeling of S-nitrosothiols (S-FLOS) to detect nitrosated cysteines in proteins, and ion mapping methods to map post-translational modifications that produce a signature mass or mass difference when the modified peptide is fragmented.

The David Graham Lab studies the consequences of HIV interactions with the immune system, the resulting pathogenesis and how to sabotage these interactions. We apply advanced technologies like mass spectrometry to dissect processes at the molecular level. We are also actively involved in cardiovascular research and studies the ways proteins are organized into functional units in different cell types of the heart. Major projects in our lab are organized into three major areas: (1) H/SIV pathogenesis and neuropathogenesis, (2) Cardiovascular disease, and (3) High technology development

The Glunde lab is within the Division of Cancer Imaging Research in the Department of Radiology and Radiological Science. The lab is developing mass spectrometry imaging as part of multimodal molecular imaging workflows to image and elucidate hypoxia-driven signaling pathways in breast cancer. They are working to further unravel the molecular basis of the aberrant choline phospholipid metabolism in cancer. The Glunde lab is developing novel optical imaging agents for multi-scale molecular imaging of lysosomes in breast tumors and discovering structural changes in Collagen I matrices and their role in breast cancer and metastasis.

A. Laboratory activities include the use of accelerator mass spectrometry (AMS) techniques to measure intracellular drugs and drugs metabolites. AMS is a highly sensitive method for detecting tracer amounts of radio-labeled molecules in cells, tissues, and body fluids. We have been able to measure intracellular zidovudine triphosphate (the active anabolite of zidovudine) in peripheral blood mononuclear cells from healthy volunteers given small doses of 14C-zidovudine, and have directly compared the sensitivity of AMS to traditional LC/MS methods carried out in our laboratory. B. Clinical research activities investigate the clinical pharmacology of new anti-HIV therapies and drug combinations. Specific drug classes studied include HIV reverse transcriptase inhibitors, protease inhibitors, entry inhibitors (selective CCR5 and CXCR4 antagonists), and integrase inhibitors. Scientific objectives of clinical studies include characterization of early drug activity, toxicity, and pharmacokinetics. Additional objectives are characterization of pathways of drug metabolism, and identification of clinically significant harmful and beneficial drug interactions mediated by hepatic and intestinal cytochrome P450 isoforms.

The CRCIF was established to foster collaborative efforts aimed at elucidating the role of intermediate filaments (IFs) in the heart. Intermediate filaments constitute a class of cytoskeletal proteins in metazoan cells, however, different from actin microfilaments and tubulin microtubules, their function in cardiac cells is poorly understood. Unique from the other two components of the cytoskeleton, IFs are formed by cell type-specific proteins. Desmin is the main component of the IFs in the cardiac myocytes. We measured the consistent induction of desmin post-translational modifications (PTMs, such as phosphorylation, etc.) in various clinical and experimental models of heart failure. Therefore, one of our main focuses is to determine the contribution of desmin PTMs to the development of heart failure in different animal and clinical models. Active Projects: • Quantification of desmin PTM-forms in different forms of heart failure at the peptide level using mass spectrometry • Functional assessment of the role of desmin PTMs in heart failure development using single site mutagenesis and biophysical methods • Molecular characterization of desmin preamyloid oligomers using mass spectrometry, in vitro and in vivo imaging • Assessment of the diagnostic and pharmacological value of desmin PTMs in heart failure development

Dr. Haughey directs a disease-oriented research program that address questions in basic neurobiology, and clinical neurology. The primary research interests of the laboratory are: 1. To identify biomarkers markers for neurodegenerative diseases including HIV-Associated Neurocognitive Disorders, Multiple Sclerosis, and Alzheimer’s disease. In these studies, blood and cerebral spinal fluid samples obtained from ongoing clinical studies are analyzed for metabolic profiles through a variety of biochemical, mass spectrometry and bioinformatic techniques. These biomarkers can then be used in the diagnosis of disease, as prognostic indicators to predict disease trajectory, or as surrogate markers to track the effectiveness of disease modifying interventions. 2. To better understand how the lipid components of neuronal, and glial membranes interact with proteins to regulate signal transduction associated with differentiation, motility, inflammatory signaling, survival, and neuronal excitability. 3. To understand how extracellular vesicles (exosomes) released from brain resident cells regulate neuronal excitability, neural network activity, and peripheral immune responses to central nervous system damage and infections. 4. To develop small molecule therapeutics that regulate lipid metabolism as a neuroprotective and restorative strategy for neurodegenerative conditions.