In JoVE (1)
Articles by A. Clementina Mesaros in JoVE
Cellular Lipid Extraction for Targeted Stable Isotope Dilution Liquid Chromatography-Mass Spectrometry Analysis Stacy L. Gelhaus1,2, A. Clementina Mesaros1,2, Ian A. Blair1,2 1Centers for Cancer Pharmacology and Excellence in Environmental Toxicology, University of Pennsylvania, 2Department of Pharmacology, University of Pennsylvania This protocol will demonstrate the extraction and analysis of free and esterified bioactive fatty acids from cells. Fatty acids are accurately quantified using stable isotope dilution, chiral liquid chromatography, electron capture atmospheric chemical ionization multiple reaction monitoring mass spectrometry (SID-LC-ECAPCI-MRM/MS).
Other articles by A. Clementina Mesaros on PubMed
20-HETE Mediates Ozone-induced, Neutrophil-independent Airway Hyper-responsiveness in Mice PloS One. 2010 | Pubmed ID: 20422032 Ozone, a pollutant known to induce airway hyper-responsiveness (AHR), increases morbidity and mortality in patients with obstructive airway diseases and asthma. We postulate oxidized lipids mediate in vivo ozone-induced AHR in murine airways.
Stereospecific Reduction of 5Î²-reduced Steroids by Human Ketosteroid Reductases of the AKR (aldo-keto Reductase) Superfamily: Role of AKR1C1-AKR1C4 in the Metabolism of Testosterone and Progesterone Via the 5Î²-reductase Pathway The Biochemical Journal. Jul, 2011 | Pubmed ID: 21521174 Active sex hormones such as testosterone and progesterone are metabolized to tetrahydrosteroids in the liver to terminate hormone action. One main metabolic pathway, the 5Î²-pathway, involves 5Î²-steroid reductase (AKR1D1, where AKR refers to the aldo-keto reductase superfamily), which catalyses the reduction of the 4-ene structure, and ketosteroid reductases (AKR1C1-AKR1C4), which catalyse the subsequent reduction of the 3-oxo group. The activities of the four human AKR1C enzymes on 5Î²-dihydrotestosterone, 5Î²-pregnane-3,20-dione and 20Î±-hydroxy-5Î²-pregnan-3-one, the intermediate 5Î²-dihydrosteroids on the 5Î²-pathway of testosterone and progesterone metabolism, were investigated. Product characterization by liquid chromatography-MS revealed that the reduction of the 3-oxo group of the three steroids predominantly favoured the formation of the corresponding 3Î±-hydroxy steroids. The stereochemistry was explained by molecular docking. Kinetic properties of the enzymes identified AKR1C4 as the major enzyme responsible for the hepatic formation of 5Î²-tetrahydrosteroid of testosterone, but indicated differential routes and roles of human AKR1C for the hepatic formation of 5Î²-tetrahydrosteroids of progesterone. Comparison of the kinetics of the AKR1C1-AKR1C4-catalysed reactions with those of AKR1D1 suggested that the three intermediate 5Î²-dihydrosteroids derived from testosterone and progesterone are unlikely to accumulate in liver, and that the identities and levels of 5Î²-reduced metabolites formed in peripheral tissues will be governed by the local expression of AKR1D1 and AKR1C1-AKR1C3.