Qing Jiang, Ph.D. Associate Professor Foods and Nutrition
Purdue University Stone Hall 700 West State Street West Lafayette, IN 47907 Phone: (765)494-2483 Fax: (765)494-0674 Email: qjiang@purdue.edu
EDUCATION BACKGROUND
Ph.D. in Biochemistry at Washington State University in 1997
AWARDS AND HONORS
1997
Elected Member
Sigma Xi Scientific Research Society
2001
Postdoctoral Fellowship Award
American Heart Association
DISCOVERY
Chronic inflammation constitutes one of the major etiologies of degenerative diseases including cancer. My laboratory is interested in studying the molecular mechanism of inflammation-associated diseases, and exploring prevention and therapy of these diseases, using nutrition factors including natural forms of vitamin E as well as combinations of vitamin E forms and other antioxidants.
During inflammation, pro-inflammatory eicosanoids including cyclooxygenase-catalyzed prostaglandin E2 (PGE2) and lipoxygenase-catalyzed leukotriene B4 (LTB4), and pro-inflammatory cytokines like TNF-alpha, play the central roles in regulating inflammatory response and inflammation-mediated damage. Eicosanoids generated through cyclooxygenase and lipoxygenase also promote tumorigenesis.
Vitamin E comprises eight structurally related molecules [alpha-, beta-, gamma-, delta-tocopherol, and alpha-, beta-, gamma-, delta-tocotrienol]. Among them, only alpha-tocopherol, the major form of vitamin E in tissues and most supplements, has been extensively studied, but other forms were mostly ignored. We have recently discovered that some non-alpha forms of vitamin E have unique properties which are important to improving human health. For instance, gamma-tocopherol, the major form of vitamin E in US diets, and its major metabolite, but not alpha-tocopherol, exhibit anti-inflammatory effects by inhibiting PGE2 and LTB4 and reducing TNF-alpha in cell culture and a rat inflammation model. We are currently focusing on the following three projects:
1. Vitamin E forms as anti-inflammatory agents
We are currently investigating the interaction between vitamin E molecules and different isoforms of cyclooxygenase and lipoxygenase, as well as the role of vitamin E in gene regulation during inflammation. We are testing the pharmaceutical utilities of vitamin E forms as novel anti-inflammatory agents in animal models.
2. Vitamin E forms as anti-cancer agents
We have recently showed that gamma-tocopherol, but not alpha-tocopherol, inhibits growth and induces cell dealth in prostate and lung cancer cells but has no effect on normal prostate epithelial cells. Our study demonstrates that gamma-tocopherol induce cell death by interrupting sphingolipid synthesis. We are planning to investigate the molecular interaction between vitamin E forms and various key enzymes in the pathway of de novo synthesis of sphingolipids, the role of these enzymes in cell fate, and testing the anti-cancer potential of vitamin E forms in various cancer models in animals.
3. Vitamin E forms and asthma
In airway inflammation in asthma, myeloperoxidase from neutrophils and eosinophil peroxidase from eosinophils generate highly potent oxidants that cause oxidative damage. We are investigating the potential detoxification of the damage caused by these peroxidases by vitamin E forms and other antioxidants. In cells mediating inflammatory response in asthma, the effect and mechanism of antioxidants on key regulatory pathways of inflammation will be studied.
Discovery Publications (selected)
Freiser H and Jiang, Q* (2009) Gamma-tocotrienol and gamma-tocopherol are primarily metabolized to conjugated 2-(beat-carboxyethyl)-6-hydroxychroman and sulfated long-chain carboxychromanols in rats. J. Nutr. In press.
Freiser H and Jiang Q* (2009) Optimization of the enzymatic hydrolysis and analysis of plasma conjugated gamma-CEHC and sulfated long-chain carboxychromanols, metabolites of vitamin E. Anal Biochem. 2009 May 15;388(2):260-5.
Qing Jiang*, Xinmin Yin, Markus A. Lill, Matthew L. Danielson, Helene Freiser and Jianjie Huang (2008) Long-chain carboxychromanols, metabolites of vitamin E, are potent inhibitors of cyclooxygenases. Proc. Natl. Acad. Sci. USA. 105, 20464-20469
Qing Jiang*, Michelle Moreland, Bruce N. Ames and Xinmin Yin (2008) A combination of aspirin and gamma-tocopherol is better than that of aspirin and alpha-tocopherol in anti-inflammatory action and attenuating aspirin-caused adverse effects. J. Nutr. Biochem. 2008 Nov 5. [Epub ahead of print]
Wagner JG, Jiang Q, Harkema JR, Ames BN, Illek B, Roubey RA, Peden DB (2008) Gamma-tocopherol prevents airway eosinophilia and mucous cell hyperplasia in experimentally induced allergic rhinitis and asthma.Clin Exp Allergy. 38(3):501-11. Epub 2007 Oct 26
Wagner, JG, Jiang Q, Harkema JR, Illek B, Patel DD, Ames BN, Peden DB (2007)
Ozone Enhancement of Lower Airway Allergic Inflammation is Prevented By Gamma-Tocopherol. Free Radical Biology & Medicine, 43(8):1176-88. Epub 2007 Jul 20.
Jiang Q*, Freiser H, Wood KV and Yin X (2007) Identification and quantitation of novel vitamin E metabolites, sulfated long-chain carboxychromanols, in human A549 cells and in rats. J. Lipid Res. 48, 1221-30.
Reiter, E., Jiang, Q., and Christen, S. (2007) Anti-inflammatory properties of alpha- and gamma-tocopherol. Mol. Aspect Med, 28(5-6):668-91. Epub 2007 Jan 11.
Walter PB, Fung EB, Killilea DW, Jiang Q, Hudes M, Madden J, Porter J, Evans P, Vichinsky E and Harmatz P (2006) Oxidative stress and inflammation in iron-overloaded patients with beta-thalassaemia or sickle cell disease. British J. Haematology, 135, 254-263.
Jiang Q*, Wong J, Fyrst H, Saba J and Bruce N Ames (2004) Gamma-tocopherol or Combinations of vitamin E forms induce cell death in human prostate cancer cells by interrupting sphingolipid synthesis. Proc. Natl. Acad. Sci. USA, 101, 17825-17830.
Books, Chapters, and Monographs Publications
Jiang, Q* (2008) The metabolism of tocopherols and tocotrienols, and novel functions of their metabolites. in
Tocotrienols: Vitamin E beyond tocopherols. Eds: Ronald R. Watson. Taylor & Francis Group LLC. 309-329.
Jiang Q* (2006) Vitamin E forms as anti-inflammatory and anti-cancer agents by inhibiting cyclooxygenase mediated reactions and interrupting of sphingolipid synthesis. in Encyclopedia of vitamin E. Eds: Victor R. Preedy and Ronald R Watson. CABI Publishing. 785-796.
LEARNING
Courses
Nutrition and Cancer (F & N 590 - special topic) This course provides an overview of the principles of cancer biology, identifies approaches to study the role of specific nutrients or bioactive compounds in molecular pathogenesis of cancer, and discusses existing research on the influence of dietary factors on cancer disease risk.
FN 607: Nutritional Biochemistry and Physiology III
F&N 695: Seminar in Foods and Nutrition
F&N 438: Micronutrient Metabolism
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Contact Information
Foods and Nutrition Purdue University 700 W. State Street West Lafayette, IN 47907-2059
