Our research mission covers both basic and translational aspects of nutritional genomics. The scope spans from the fundamental mechanisms of antioxidant nutrients and enzymes in metabolism and pathogenesis of chronic diseases, to the development of novel hydrolytic enzymes and alternative feed/food protein sources. We are actively involved in the global biofortification of staple crops with the micronutrients iron, zinc, and pro-vitamin A. Our experimental models include food-producing species pigs and chickens, laboratory species rats and gene-knockout mice, primary and cultured cells, yeast, and bacteria, while our approaches consist of nutritional, molecular, biochemical, biophysical, and physiological methods, along with cutting-edge genomics, proteomics, and bioinformatics. Our findings aim at directly improving human health, food security, and environmental sustainability worldwide.
Our laboratory is conducting active research in four exciting areas. The first area, funded by NIH, is molecular nutrition of selenium and functional genomics of antioxidant enzymes. Applying gene-knockout and overexpressing mouse models, our group produced the first direct evidence for an in vivo antioxidant role of selenium-dependent glutathione peroxidase-1 (GPX1), and a contrasting role of GPX1 and Cu,Zn superoxide dismutase (SOD1) in coping with reactive oxygen species vs. reactive nitrogen species. Most striking, we found that overproduction of GPX1 in mice induced type 2 diabetes-like phenotypes. These discoveries help explain recently-observed alarming pro-diabetic potential of Se supplements in humans, and provide strong data to revise current theory and application of antioxidants. Subsequently, we are elucidating the molecular mechanism and signal transduction for the role of selenium and selenoproteins in regulating energy, fat, and protein metabolism. We are also illustrating systematic regulations of the selenoprotein genome by dietary selenium in pigs and chicks, and unveiling molecular mechanisms for pathogeneses of classical selenium/vitamin E deficiency diseases such as exudative diathesis and pancreatic atrophy in chicks.
Our second area is to overexpress and engineer phytases and proteases for improving mineral (P, Ca, Fe, and Zn) and protein nutrition and to protect environmental pollution of animal waste. Our pioneering research on bacterial phytase has led to the discovery, development, and worldwide commercialization of the second generation of phytases. The field application of these phytases has allowed a global reduction of phosphorus excretion from animal waste thereby benefiting the environment and preserving non-renewable inorganic phosphorus deposit. We are currently applying genomics, proteomics, and bioinformatics to reveal feather-degrading mechanisms of microbes and developing novel proteases for converting over 100 million tons of poultry feathers into feed protein supplements.
Our third and fourth areas address global food and nutrition security, along with exploring new biofuel sources. The fast growing world population and the accelerated urbanization lead to a greater demand for animal production and in turn the need for animal feeds. Because the major energy and protein feeds, such as corn and soy, are staples for human diets, their massive use in the animal feeding creates a direct competition with human consumption. Alternative feed ingredients must be explored to sustain the current growth in animal production. Funded by the USDA/DOE, we are collaborating with the biofuel industry to evaluate defatted microalgal biomass as a new source of feed protein for broiler chicks, layer hens, pigs, and pets. We are also exploring the unique potential of the biomass to produce health value-added animal products. Due to poverty and decreased food diversity, 30-40% of the world population suffers from iron, zinc, and vitamin A deficiencies. We are actively engaged in the international mission to apply new agriculture technologies for biofortifying staples with those nutrients (HarvestPlus program-http://www.HarvestPlus.org, plant breeding for better nutrition). While we use pigs as a model to study determinants of iron bioavailability in staple crops, we have introduced the HarvestPlus program to China where a national team of over 100 Chinese scientists are working together to deliver this program.
Outreach and Extension Focus
Associate Editor (2008-2017), Journal of Nutrition (http://submit.nutrition.org);
Editorial Committee (2015-2017), Annual Review of Animal Biosciences
Associate Director (2004-present), HarvestPlus-China Program (http://harvestplus-china.org);
International Parent Committee (2005-present), Trace Elements in Man and Animals (http://www.rowett.ac.uk/tema/index.html);
President (2012-2014), North America Chinese Society for Nutrition (http://nacsn.org/);
Faculty Member (1997-present), Cornell Institute for Food Systems (CIFS);
Faculty Member (2010-present), Cornell Energy Institute (http://energyinstitute.engineering.cornell.edu/node/74);
Faculty Member (2010-present), Cornell East Asia Program (http://eap.einaudi.cornell.edu/node/8174);
Faculty Member (2008-present), Cornell University Center for Vertebrate Genomics (http://www.vertebrategenomics.cornell.edu/);
ACSF Faculty Fellows (2011-present), David R. Atkinson Center for a Sustainable Future (http://www.acsf.cornell.edu/index.php)
I teach Animal Science 3980: Animals in Biomedical Research. This course introduces features and applications of various animal models for biomedical research on human health and diseases. Emphasis is placed on appropriate animal models for studying human development, diabetes, cancer, cardiovascular diseases, hereditary diseases, and nutritional deficiencies. I have also taught a graduate course of Advanced Mineral Nutrition including minerals in metabolism, gene expression, chronic disease, food supplementation, and biofortification and an introductory course of Animal Science and Society.
Every semester, my laboratory hosts 5-8 undergraduate students majoring in animal science, biology, nutrition and other fields to conduct independent and honors thesis research. These students are not only involved in performing complete research projects, but also in applying for grants, writing papers, and presenting findings at national and professional meetings.
Awards and Honors
- Honorary Citizen of Enshi, Hubei, China, September, 2011 by the government for contribution (2011) Enshi Government, Hubei, China
- The 1000 People Plan Professor (2010) The central government of China
- President (2014) North American Chinese Society for Nutrition
- The Bouffault International Animal Agriculture Award (2013) American Society of Animal Science
- The Milton L. Sunde Award (2012) American Society for Nutrition
- Lei, X., Xiao, C., Lei, X. G., Wang, Q., Du, Z., Jiang, L., Chen, S., Zhang, M., Zhang, H., & Ren, F. Z. (2016). Effects of a tripeptide iron on iron-deficiency anemia in rats. Biol. Trace Elem. Res.. 169:211-217.
- Lei, X., Mai, H. N., Jeong, J. H., Kim, D. J., Chung, Y. H., Shin, E. J., Nguyen, L. T., Nam, Y., Lee, Y. J., Cho, E. H., Nah, S. Y., Jang, C. G., Lei, X., & Kim. 2016., H. C. (2016). Genetic overexpressing of GPx-1 attenuates cocaine-induced renal toxicity via induction of anti-apoptotic factors. Clinical and experimental pharmacology & physiology. 43:428–437.
- Lei, X., Zhao, Z. P., Barcus, M., Kim, J. G., Lum, K., Mills, C., & Lei, X. G. (2016). High dietary selenium intake alters lipid metabolism and protein synthesis in liver and muscle of pigs. Journal of Nutrition, The. 146:1625-1633.
- Kim, J. G., Magnuson, A., Tao, L., Barcus, M., & Lei, X. (2016). Potential of combining flaxseed oil and microalgal biomass in producing eggs-enriched with n-3 fatty acids for meeting human needs. Algal Res.. 17:31-37.
- Lei, X., Nguyen, T. H., Mai, H. N., J. Shin, E., Nam, Y., Nguyen, B. T., Lee, Y. J., Jeong, H., Cho, E. H., Nah, S. Y., Lei, X. G., T. Nabeshima, T., Kim, N. H., & Kim, H. C. (2016). Repeated exposure to far infrared ray attenuates acute restraint stress in mice via inhibition of JAK2/STAT3 signaling pathway by induction of glutathione peroxidase-1. Neurochem. Int.. 94:9-22..
- Prabhu, K. S., & Lei, X. (2016). Selenium. Advances in Nutrition. 7:415-417.
- Lei, X., Du, Q., Yao, H. D., Yao, L. L., Zhang, Z. W., Lei, X. G., & Xu, S. W. (2016). Selenium deficiency influences the expression of selenoproteins and inflammatory cytokines in chicken aorta vessels. Biol. Trace Elem. Res.. 173:501-513..
- Kim, J. G., Barcus, M., Magnuson, A., Tao, L., & Lei, X. (2016). Supplemental defatted microalgae affects egg and tissue fatty acid composition differently in laying hens fed diets containing corn and flaxseed oil. J. Appl. Poult. Res.. 25:528-538.
- Q. Huang, J., Ren, F. Z., Jiang, Y. Y., & Lei, X. (2016). Characterization of selenoprotein M and its response to selenium deficiency in chicken brain. Biological trace element research. 170:449-458.
- Lei, X., Zhu, J. H., Cheng, W. H., Bao, Y. P., Ho, Y. S., Reddi, A. R., Holmgren, A., & Arnér, E. (2016). Paradoxical functions of antioxidant enzymes: basic mechanisms and health implications. Physiological reviews. 96:307-364.
Presentations and Activities
- Dual roles of selenium in diabetes, and publishing nutrition research, Department of Food Science, School of Pharmacy, University of Sao Paulo. Sepcial Seminar for University of Sao Paulo. October 2015. Sao Paulo, Brazil.