Educational Background - Ph.D., Biochemistry at Washington State University in 1997
- Postdoc, Biochemistry at Unversity of California, Berkeley in 2001
Awards & Honors - Purdue Entrepreneurial Leadership Academy Fellow from Purdue University, 2011
- E.L.R. Stokstad Award from the American Society for Nutrition , 2011
- Postdoctoral Fellowship Award from American Heart Association, 2001
- Elected Member from Sigma Xi Scientific Research Society, 1997
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 - Qing Jiang*, Xiayu Rao, Choon Young Kim, Helene Freiser, Qingbo Zhang, Ziying Jiang and Guilan Li (2011) Gamma-tocotrienol induces apoptosis and autophagy in prostate cancer cells by increasing intracellular dihydrosphingosine and dihydroceramide. Int. J. Cancer. 130(3): 685-93.
- Jiang, Ziying, Yin Xinmin Yin and Jiang Q* (2011) Natural forms of vitamin E and 13 -carboxychromanol, a long-chain vitamin E metabolite, inhibit leukotriene generation from stimulated neutrophils by blocking calcium influx and suppressing 5-lipoxygenase activity, respectively. J. Immunology. 186: 1173-9.
- Yun Wang, Michelle Moreland, James G Wagner, Bruce N. Ames, Beate Illek, David B. Peden and Qing Jiang* (2011) Vitamin E forms inhibit IL-13/STAT6-induced eotaxin-3 secretion by upregulation of PAR4, an endogenous inhibitor of atypical PKC in human lung epithelial cells. J Nutr Biochem., In press.
- Freiser H and Jiang, Q* (2009) Gamma-tocotrienol and gamma-tocopherol are primarily metabolized to conjugated 2-(gamma-carboxyethyl)-6-hydroxy-2,7,8-trimethylchroman and sulfated long-chain carboxychromanols in rats. J. Nutr. 139: 884-9.
- 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*, Michelle Moreland, Bruce N. Ames and Xinmin Yin (2009) 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. 20(11):894-900
- 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
- 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.
Books, Chapters & Monograph Publications - 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.
- 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.
- Silvia Moya and Qing Jiang* (2011) The role of vitamin E forms in cancer prevention and therapy - Studies in human intervention trails and animal models. In Nutraceuticals and Cancer. Ed: Fazlul H. Sarkar. Springer, In press.
Learning FN 43800
| Micronutrient Metabolism
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FN 59000/NUTR63400
| Nutrition and Cancer: 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.
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FN 60700
| Nutritional Biochemistry and Physiology III
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FN 69500
| Seminar in Foods and Nutrition
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