Miao Li
Before I came to the US, I was trained as a biological and pharmaceutical researcher with a background in health science, pharmacy, chemistry and biology in a combined bachelor’s/master’s program. I had research background of both in vitro cell models and in vivo animal models (including mouse, rat, rabbit, and zebrafish).
My research goal was to build up a simple animal model to predict preclinical toxicity of chemicals. We used rat models to test the neurotoxicity caused by alumina oxide nanoparticles, and prenatal exposed rats to study the toxicity of PFOS. I also helped to establish methods using the probe modified gold nanoparticles and to measure chemical pollutants and microRNA from environmental and cell culture samples.
I came to US with an interest in toxicology. Toxicology is the practical science with a multifactorial and multidisciplinary nature. Toxicologists should know and apply the cutting edge technologies to study the mechanism of toxicity. However, there are still a lot of unknown aspects in toxicology. With the incredible increase of man-made chemicals, the development of toxicology currently cannot meet the requirements.
Research Description:
I joined Dr. Gabriele Ludewig’s lab after my first year lab rotation. I worked with the toxicity mechanism of airborne PCBs by the formation of protein adducts. Previous research found that the lower chlorinated PCBs, with 1-4 chlorines, are ready to be metabolized to reactive compounds as quinoid and arene oxide metabolites. The metabolites may be the principal cause for the toxicity of airborne PCBs. However, little is known about the toxicity of PCB metabolites.
Quinoid and arene oxide metabolites of PCBs covalently bind to the key macromolecules as DNA, RNA and proteins. The formation of adducts may contribute to the major toxicity of airborne PCBs. My research found the PCB quinones covalently bind to cytochrome c to cause crosslinking of cytochrome c and dysfunction of cytochrome c as an electron acceptor. I also established the alkaline permethylation method to measure the amount of PCB metabolites forming protein adducts.
However, the tough part about studying protein adducts is to quantitatively identify and profile the lower abundant target proteins in cell or animal samples. I applied SILAC and RBPP method to profile the target proteins in cell culture samples, which may provide valuable information for PCB toxicity.
Thesis Title: Protein Adducts and Crosslinking by Reactive Metabolites of Polychlorinated Biphenyls (PCBs)
Advisor: Gabriele Ludewig, Ph.D.
Year of Graduation: 2015
Program: Ph.D.
Current Position: Visiting Scientist
Current Employer/Institution: Food and Drug Administration
Publications from Human Toxicology Program Research:
M Li, L Teesch, LW Robertson, G Ludewig. Application of alkaline permethylation method to measure protein adducts with PCB metabolites. In preparation.
M Li, L Teesch, DJ Murry, RM Pope, LW Robertson, G Ludewig. Cytochrome c adducts with PCB quinoid metabolites, Environmental Science and Pollution Research, volume 23, pages 2148–2159 (2016)
H Shen, M Li, B Wang, IK Lai, LW Robertson, G Ludewig. Dietary antioxidants (selenium and N-acetylcysteine) modulate paraoxonase 1 (PON1) in PCB 126-exposed rats. Environmental Science and Pollution Research 21(10), 6384-99.
KN Salman, MA Stuart, J Schmidt, T Borges, CJ McClain, FR Robinson, M Li, LW Robertson. The effects of 3, 3’, 4, 4’-tetrabromobiphenyl on rats fed diets containing a constant level of copper and varying levels of molybdenum. Environmental Science and Pollution Research 21(10), 6400-09.
IK Lai, WD Klaren, M Li, B Wels, DL Simmons, AK Olivier, WM Haschek, LW Robertson. Does dietary copper supplementation enhance or diminish PCB126 toxicity in the rodent liver? Chemical research in toxicology 26 (5), 634-44.
IK Lai, K Dhakal, GS Gadupudi, M Li, G Ludewig, LW Robertson, AK Olivier. N-acetylcysteine (NAC) diminishes the severity of PCB 126-induced fatty liver in male rodents. Toxicology. 2012 Dec 8;302(1):25-33.
