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PART I: FORMATION, PROTEIN MODIFICATION, AND CELLULAR METABOLISM OF 4-HYDROXY-7-OXOHEPT-5-ENOIC ACID LACTONE (HOHA-LACTONE) PART II: DETECTION AND BIOLOGICAL ACTIVITIES OF CARBOXYETHYLPYRROLE (CEP)-PHOSPHATIDYL-ETHANOLAMINE AND METABOLISM OF CEP-LYSINE

Wang, Hua
http://rave.ohiolink.edu/etdc/view?acc_num=case1386252158

Abstract Details

2014, Doctor of Philosophy, Case Western Reserve University, Chemistry.
Oxidation of phospholipids containing docosahexaenoate leads to the formation of 4-hydroxy-7-oxo-hept-5-enoyl phospholipids (HOHA-PLs) that were previously shown to react with biological primary amines to deliver 2-¿-carboxyethylpyrroles (CEPs), which are novel factors that induce angiogenesis. A spontaneous deacylation product of HOHA-PLs, 4-hydroxy-7-oxo-5-heptenoic acid (HOHA)-lactone, was now found to react with proteins to generate CEPs. An in vitro study found that HOHA-PC forms CEP modifications primarily through initial release of HOHA-lactone followed by reaction of this intermediate with the epsilon-amino group of lysyl residues. These observations, along with the fact that HOHA-lactone was directly produced during lipid oxidation, suggest a novel mechanism of CEP generation in vivo that involves HOHA-lactone as a major intermediate. The metabolism of HOHA-lactone in cells suggests a cellular self-defense system against CEP generation. In a noncytotoxic dose, HOHA-lactone was found to diffuse rapidly into cultured a human retinal pigmented epithelium cell line (ARPE-19) and was metabolized to glutathione adducts and a carboxylic acid derivative, which were then secreted by the cells to extracellular medium. Our study showing that, although it is cytotoxic at high concentration levels, low levels of HOHA-lactone induce RPE cell proliferation and stimulate the secretion of vascular endothelial growth factor (VEGF). These findings suggest that HOHA-lactone plays a role in oxidative stress-induced cell signaling. CEP-derivatives of phosphatidylethanolamines (CEP-PEs) were also found to have proangiogenic effects similar to CEP-protein derivatives. A mass spectrometric assay was developed involving phospholipase D-promoted conversion to a CEP-ethanolamine derivative. The method was applied to the analysis of CEP-PEs in phospholipid extracts of human plasma. Elevated CEP-PE levels were found in plasma from AMD patients compared to plasma from healthy controls. In vivo, CEP-derived proteins were postulated to be degraded by proteasomes and cellular proteases to CEP-lysine. In an in vitro model experiment, CEP-lysine and its isotopomers were synthesized and then perfused to rat livers. Two major metabolites of CEP-lysine were identified and characterized by mass spectrometric analysis. CEP-BSA protein perfused in rat liver was found to be degraded to produce CEP-lysine and CEP-lysine-derived metabolites. Overall, this thesis provided a new understanding of the mechanism for CEP generation and metabolism.
Robert Salomon (Advisor)
Michael Zagorski (Committee Chair)
Gregory Tochtrop (Committee Member)
Irene Lee (Committee Member)
Henri Brunengraber (Committee Member)
222 p.
Analytical Chemistry; Biochemistry; Chemistry
Lipid oxidation, protein modification, metabolism, carboxyethylpyrrole, liver perfusion, human RPE cells, age related macular degeneration

Recommended Citations

Citations

  • Wang, H. (2014). PART I: FORMATION, PROTEIN MODIFICATION, AND CELLULAR METABOLISM OF 4-HYDROXY-7-OXOHEPT-5-ENOIC ACID LACTONE (HOHA-LACTONE) PART II: DETECTION AND BIOLOGICAL ACTIVITIES OF CARBOXYETHYLPYRROLE (CEP)-PHOSPHATIDYL-ETHANOLAMINE AND METABOLISM OF CEP-LYSINE [Doctoral dissertation, Case Western Reserve University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=case1386252158

    APA Style (7th edition)

  • Wang, Hua. PART I: FORMATION, PROTEIN MODIFICATION, AND CELLULAR METABOLISM OF 4-HYDROXY-7-OXOHEPT-5-ENOIC ACID LACTONE (HOHA-LACTONE) PART II: DETECTION AND BIOLOGICAL ACTIVITIES OF CARBOXYETHYLPYRROLE (CEP)-PHOSPHATIDYL-ETHANOLAMINE AND METABOLISM OF CEP-LYSINE . 2014. Case Western Reserve University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=case1386252158.

    MLA Style (8th edition)

  • Wang, Hua. "PART I: FORMATION, PROTEIN MODIFICATION, AND CELLULAR METABOLISM OF 4-HYDROXY-7-OXOHEPT-5-ENOIC ACID LACTONE (HOHA-LACTONE) PART II: DETECTION AND BIOLOGICAL ACTIVITIES OF CARBOXYETHYLPYRROLE (CEP)-PHOSPHATIDYL-ETHANOLAMINE AND METABOLISM OF CEP-LYSINE ." Doctoral dissertation, Case Western Reserve University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=case1386252158

    Chicago Manual of Style (17th edition)

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This open access ETD is published by Case Western Reserve University School of Graduate Studies and OhioLINK.