Joy Winzerling, PhD, RD

Professor Emerita, Department of Nutritional Sciences

Associate Dean, Bart Cardon Career and Academic Services

EDUCATION & TRAINING

  • Ph.D., Nutritional Sciences, University of Arizona
  • M.S., Agricultural Biochemistry, University of Arizona
  • B.S., Biological Sciences, University of Arizona
  • R.D. Registered Dietitian

ACADEMIC ACTIVITIES

  • NSC 622A - Mineral Metabolism

RESEARCH ACTIVITIES

Our area of research is comparative nutrition. Currently we have several research projects focusing on the metabolism of metal-binding proteins with an emphasis on proteins that are regulated by iron. Iron is a required nutrient for most species and organisms have evolved ways to use iron while preventing iron-mediated free radical formation. Our primary research involves studying iron metabolism in the mosquito disease vectorsAedes aegypti and Anopheles gambiae.

These mosquitoes transmit dengue, yellow fever and malaria. The females require a blood meal for oogenesis and receive an iron load in this meal. One mechanism that allows the vectors to adapt to this load is iron storage inside ferritin. We have been studying mechanisms involved in the control of ferritin synthesis. In a second project, we are evaluating candidate proteins for mosquito iron metabolism by mass spectrometry of the iron ovarian proteome of A. aegypti. Part of the iron requirement in vectors could reflect the demand for ribonucleotide reductase (RNR). We are collaborating with Dr. Daphne Pham, a molecular entomologist at the University of Wisconsin, studying iron-mediated transcriptional control of RNR in mosquitoes.
In addition to our work in mosquitoes, we also are interested in relationship of environmental contaminants to intracellular nutritional status in man. We are currently studying the effects of airborne iron particles on iron metabolism of human lung cells. We have found that lung cell ferritin is down regulated in presence of smoke. This could impair cells from storing iron at a time when exposure to oxidative compounds is increased.
Because of our cross-disciplinary work in insects, we have an international effort with Dr. Luz Vazquez from the Centro de Investigacion en Alimentacion y Desarrollo, Hermosillo, Mexico. We have discovered a lectin (protein) from a desert plant that kills the larvae of a pest that destroys common beans. We are currently studying the structure and properties of this protein. In addition, we are working on using nanoparticles to assist with identification of glycoprotein ligands from pathological gut bacteria.

Mosquito Iron Metabolism and Fecundity
Diseases transmitted by mosquitoes are estimated to kill more than 2 million people annually. The vector for dengue, Aedes aegypti (yellow fever mosquito), is found in the desert Southwest of the continental United States. One approach to limiting the spread of disease is to reduce the numbers of mosquito vectors. Our area of research is iron metabolism.  Our long term goal is to use molecular techniques to alter the expression of iron related proteins in mosquitoes to reduce mosquito fecundity (reproductive ability) and survival. Our hypothesis is that female mosquitoes require iron in the blood meal as an essential nutrient to aid in egg development. Although the iron is necessary for fecundity it is also highly oxidative and toxic in biological systems unless the mineral is associated with a molecule that can mitigate its oxidative potential. One such molecule is ferritin, the primary iron storage protein. We think different ferritin subunits play a crucial role in the transport of iron from the mosquito midgut to the ovaries as well as storage of iron in the ovaries and eggs. We are currently analyzing tissue-specific, iron regulated proteins by proteomics of the mosquito ovary.  We also have initiated microscopy studies of the mosquito ovary to observe and document the iron storage pattern during oogenesis (egg development) and to detect iron metabolic proteins directly involved in ovarian iron processing. Further, we are in the process of characterizing iron metabolic proteins in cells, tissues and animal developmental stages from other significant mosquito species, Anopheles gambiae (African malaria mosquito) and An. stephensi (Asian malaria mosquito). This research will contribute to our understanding of mosquito development in general, as well as ovarian iron metabolism.

We recently assisted VectorBase.org with the annotation of iron metabolic proteins from the genomic database for the African sleeping sickness vector, Glossina mortisans mortisans (savannah tsetse fly), and have an ongoing collaboration with researchers from CIAD in Hermosillo, Mexico to characterize the larvae insecticidal mechanism of the PF2-binding lectin from Olneya tesota (desert ironwood) seeds against the main pest of Phaselous vulgaris (common beans), Zabrotes subfasciatus (Mexican bean weevil).

PUBLICATIONS