WOOSTER, Ohio -- An Ohio State University entomologist has been awarded a $1.4 million grant from the Foundation for the National Institutes of Health (FNIH) to discover chemicals that could pave the way to an entirely new way of killing mosquitoes that spread malaria, a disease that claims the lives of 1 million children around the world each year.
Peter Piermarini, an assistant professor in the Department of Entomology, leads one of four projects recently awarded nearly $6 million by FNIH as part of its "New Insecticides for Malaria Control" program. His collaborators include Klaus Beyenbach, professor of physiology at Cornell University; and Jerod Denton, assistant professor of pharmacology at Vanderbilt University.
Thanks to the three-year grant, Piermarini and his team will look for small molecules that induce "kidney failure" in Anopheles gambiae mosquitoes. Called Malpighian tubules, the "kidneys" of mosquitoes are essential for excretory processes -- especially in female mosquitoes, which ingest relatively large amounts of blood (for their body size) from humans as part of their reproductive cycle.
"Female mosquitoes may consume a volume of blood that exceeds their own body mass by two- to three-fold in a single feeding,” explained Piermarini, who is based on the Wooster campus of Ohio State's Ohio Agricultural Research and Development Center (OARDC). "To put this into perspective, it would be comparable to a human weighing 150 pounds ingesting 36-54 gallons of a protein-rich smoothie within five minutes. The engorged mosquito needs to immediately rid itself of the excess salt and water it consumes, which it does by urinating, often while it is still feeding on the host."
Hired by OARDC in the summer of 2011, Piermarini researched the mechanisms of renal function in mosquitoes while working as a postdoctoral research associate in Beyenbach's lab at Cornell. "We reasoned that if there was a way to block renal function in female mosquitoes, then this could present a new way to kill them or at least hinder their ability to reproduce," he said.
As they pursued this line of inquiry, Piermarini and Beyenbach met Denton, who is engaged in research that aims to design drugs that enhance kidney function in humans. By putting their collective expertise together, Piermarini said, "We mapped out a strategy by which we can potentially discover and design insecticides that disrupt renal function in mosquitoes."
If successful, this research would lead to the development of the first insecticide that targets the renal functions of mosquitoes. Most currently used insecticides attack the nervous systems of mosquitoes and, while effective, their overuse or misuse has promoted the evolution of mosquito populations that are resistant to the nerve-targeting insecticides. For that reason, insecticides that were once very effective at killing and controlling mosquitoes have now lost their potency.
"At the end of this project, I hope that we will be on our way toward developing a novel control agent that can effectively reduce the transmission of malarial parasites to humans by limiting the lifespan and reproductive output of adult female mosquitoes," Piermarini said.
In a release announcing the grants, FNIH underscored the need to discover novel insecticides targeted at mosquitoes.
"Controlling malaria is an ongoing global challenge, as parasites and mosquitoes are continually acquiring genetic changes to overcome and resist drugs and insecticides," the press release stated. "No new public health insecticides have been developed for malaria control for decades. There is now an urgent need for new insecticides as the existing anti-malarial approaches are losing efficacy."
"New Insecticides for Malaria Control" is part of FNIH's Vector-based Control of Transmission Discovery Research (VCTR) program, which is supported by an award from the Bill & Melinda Gates Foundation.
Established by the U.S. Congress to support NIH's mission of improving health through scientific discovery in the search for cures, FNIH is a leader in identifying and addressing complex scientific and health issues. A non-profit, charitable organization, it raises private-sector funds for a broad portfolio of programs that complement and enhance NIH priorities and activities. More information is available at http://www.fnih.org.
The largest university agricultural biosciences research center in the U.S., OARDC is the research arm of Ohio State's College of Food, Agricultural, and Environmental Sciences.