Combinatorial assessments of brain tissue metabolomics and histopathology in rodent models of human immunodeficiency virus infection

Department of Pharmacology and Experimental Neuroscience, College of Medicine, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
Journal of Neuroimmune Pharmacology (Impact Factor: 4.11). 05/2013; 8(5). DOI: 10.1007/s11481-013-9461-9
Source: PubMed


Metabolites are biomarkers for a broad range of central nervous system disorders serving as molecular drivers and byproducts of disease pathobiology. However, despite their importance, routine measures of brain tissue metabolomics are not readily available based on the requirements of rapid tissue preservation. They require preservation by microwave irradiation, rapid freezing or other methods designed to reduce post mortem metabolism. Our research on human immunodeficiency virus type one (HIV-1) infection has highlighted immediate needs to better link histology to neural metabolites. To this end, we investigated such needs in well-studied rodent models. First, the dynamics of brain metabolism during ex vivo tissue preparation was shown by proton magnetic resonance spectroscopy in normal mice. Second, tissue preservation methodologies were assessed using liquid chromatography tandem mass spectrometry and immunohistology to measure metabolites and neural antigens. Third, these methods were applied to two animal models. In the first, immunodeficient mice reconstituted with human peripheral blood lymphocytes then acutely infected with HIV-1. In the second, NOD scid IL2 receptor gamma chain knockout mice were humanized with CD34+ human hematopoietic stem cells and chronically infected with HIV-1. Replicate infected animals were treated with nanoformulated antiretroviral therapy (nanoART). Results from chronic infection showed that microgliosis was associated with increased myoinostitol, choline, phosphocholine concentrations and with decreased creatine concentrations. These changes were partially reversed with nanoART. Metabolite responses were contingent on the animal model. Taken together, these studies integrate brain metabolomics with histopathology towards uncovering putative biomarkers for neuroAIDS.

  • Source
    • "Microdialysis of metabolites from a brain tissue represents a compelling innovative strategy to assess the metabolite concentrations directly from the brain interstitial fluid, as opposed to measuring the concentrations in the blood plasma or serum (Kao et al. 2015). When the brain tissue is available from animal models, the intelligent experimental design with a highlight on an adequate metabolism quenching strategy (i.e., focused beam microwave irradiation -FBMI, funnel freezing) is essential for brain sample preparation (Epstein et al. 2013; Griffin and Salek 2007; Ivanisevic et al. 2014). Human brain tissue is difficult to procure, especially in the case of healthy control samples, and the post-mortem brain studies are further complicated through metabolic alterations that may occur in hypoxic conditions during the postmortem delays. "
    [Show abstract] [Hide abstract]
    ABSTRACT: This special edition of the Journal of Neuroimmune Pharmacology focuses on the leading edge of metabolomics in brain metabolism research. The topics covered include a metabolomic field overview and the challenges in neuroscience metabolomics. The workflow and utility of different analytical platforms to profile complex biological matrices that include biofluids, brain tissue and cells, are shown in several case studies. These studies demonstrate how global and targeted metabolite profiling can be applied to distinguish disease stages and to understand the effects of drug action on the central nervous system. Finally, we discuss the importance of metabolomics to advance the understanding of brain function that includes ligand-receptor interactions and new insights into the mechanisms of central nervous system disorders.
    Full-text · Article · Jun 2015 · Journal of Neuroimmune Pharmacology
  • Source
    • "Mice were anesthetized with 1%–2% isoflurane in oxygen then aligned in a water-jacketed holder for microwave irradiation in a Muromachi Microwave Fixation System (10 kW model). Irradiation time was 800 ms at 4.9 kW (Epstein et al., 2013). Single voxel localized spectra were acquired postmortem at the midbrain to ensure metabolite level stabilization using point resolved spectroscopy. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Historically, studies of brain metabolism have been based on targeted analyses of a limited number of metabolites. Here we present an untargeted mass spectrometry-based metabolomic strategy that has successfully uncovered differences in a broad array of metabolites across anatomical regions of the mouse brain. The NSG immunodeficient mouse model was chosen because of its ability to undergo humanization leading to numerous applications in oncology and infectious disease research. Metabolic phenotyping by hydrophilic interaction liquid chromatography and nanostructure imaging mass spectrometry revealed both water-soluble and lipid metabolite patterns across brain regions. Neurochemical differences in metabolic phenotypes were mainly defined by various phospholipids and several intriguing metabolites including carnosine, cholesterol sulfate, lipoamino acids, uric acid, and sialic acid, whose physiological roles in brain metabolism are poorly understood. This study helps define regional homeostasis for the normal mouse brain to give context to the reaction to pathological events.
    Full-text · Article · Nov 2014 · Chemistry & Biology

  • No preview · Article · Nov 2013 · Journal of Neuroimmune Pharmacology
Show more