Tuesday, December 22, 2009

The top 5 people of 2009

From budgets padded with stimulus funding to advancements in stem cell legislation, 2009 has been an all around big year for research. But in The Scientist's mind, a few individuals have stuck out in terms of their contributions, support, and leadership in the life sciences.

Here are our picks for the top five most influential people of the year, presented in alphabetical order:
Francis Collins

Unless you have been living under a rock this year, you know that Collins was appointed director of the National Institutes of Health in August. The geneticist accepted the position after 15 years at the helm of the National Human Genome Research Institute, during which time he helped finish the Human Genome Project ahead of schedule and under budget. Since taking control of the NIH, Collins has been pushing an agenda focused on personalized medicine and stem cell research, backing the efforts by approving 40 new human embryonic stem cell lines as eligible for federal funding. Collins has also found time to be a much more public figure than previous NIH directors, taking time out to rock with Aerosmith's Joe Perry and joke around with Stephen Colbert.

Sheng Ding

For the first time, Ding and colleagues at the Scripps Research Institute induced pluripotency in mouse embryonic cells using only recombinant proteins, avoiding gene manipulation altogether, publishing the research in Cell Stem Cell. The technology, which was named The Scientist's top life science tool of 2009, is being used by Fate Therapeutics, a company cofounded by Ding in 2007, to interrogate stem cell biology in an effort to enable new drug discovery. Ding was also featured in our pages as Scientist to Watch in November.

Bart Gordon

As Chairman of the House Committee on Science and Technology, the 13th term Democrat from Tennessee played a key role in ensuring science got a major boost from stimulus funding. Gordon also authored bills to further nanotechnology research and commercialization (H.R. 554, passed February 11), require that the President create a national water strategy (H.R. 1145, passed April 23), and improve science, technology, engineering, and math (STEM) education programs (H.R. 1709, passed June 8). Gordon also helped allocate $400 million in stimulus funding to start the Department of Energy's Advanced Research Projects Agency -- Energy, which funds high risk, high reward energy research. Although the Congressman announced he won't be running for re-election next year, science sure was lucky to have him around in 2009.

Henry Gustav Molaison

Known to scientists for most of his life only as H.M., Molaison is recognized as one of the most important patients in the history of brain science. After undergoing experimental surgery in 1953 to correct a seizure disorder, which included removing two slivers of brain tissue and cutting into the hippocampus, Molaison lost the ability to form new memories. For the next 55 years, he helped transform scientists' understanding of memory, including the identification of two different systems of remembrance -- declarative (names and faces, for example) and motor learning. Molaison died in December 2008 at the age of 82, but not before agreeing to donate his brain to research. This year, scientists at the University of California, San Diego, began slicing the organ into approximately 2,600 fragments in an effort to correlate individual brain structures with specific functions.

Erika Sasaki

Sasaki, from the Central Institute for Experimental Animals in Kawasaki, Japan, led the team of researchers that successfully generated the world's first transgenic primates capable of passing on a foreign gene to their offspring. The research, published in Nature, brings scientists one step closer to being able to use primates as models for studying human neurological and behavioral conditions, such as Parkinson's, Huntington's and amyotrophic lateral sclerosis. The team injected viral vectors with a green fluorescence protein transgene into embryos of marmosets. Out of 80 transgenic embryos planted into 50 surrogate mothers, five offspring survived, all of which expressed the glowing transgene.

Sunday, December 20, 2009

Parasite Evades Death By Promoting Host Cell Survival

The parasite Trypanosoma cruzi (or T. cruzi), which causes Chagas' disease, will go to great lengths to evade death once it has infected human host cells, researchers have discovered. In a study published in the November 17 online issue of Science Signaling, the researchers describe how a protein called parasite-derived neurotrophic factor (PDNF) prolongs the life of the T. cruzi parasite by activating anti-apoptotic (or anti-cell-death) molecules in the host cell. These protective mechanisms help to explain how host cells continue to survive despite being exploited by T. cruzi parasites.

"We asked ourselves, 'How is it possible that the host cells stay alive for so long with thousands of T. cruzi parasites consuming the host cell's vital resources?' We discovered that PDNF on the surface of the T. cruzi parasite essentially inhibits cell death signals and activates cell-protective mechanisms, ensuring T. cruzi sufficient time to develop and reproduce in the host cell," says senior author Mercio Perrin, MD, PhD, professor in the pathology department at Tufts University School of Medicine (TUSM) and member of the immunology program faculty at the Sackler School of Graduate Biomedical Sciences at Tufts.

Taking a multi-faceted approach, the researchers used bioinformatics, immunochemistry, intracellular colocalization microscopy, and in vitro enzymatic techniques to study T. cruzi's survival in the host. Perrin and co-author Marina Chuenkova, PhD, a research instructor in the pathology department at TUSM and the Sackler School, demonstrated that PDNF is a substrate and activator of Akt kinase, an enzyme that promotes cell survival by inhibiting "cell death" proteins.

"Further investigation showed that within T. cruzi-infected cells, PDNF also activates increased production of Akt, prolonging its protective effects," says Chuenkova. "Akt is a key regulator of diverse cellular processes, and supports cell survival not only by inhibiting apoptotic molecules, but additionally by increasing nutrient uptake and metabolism," she continued.

"In short, the T. cruzi parasite has a means of establishing life insurance once it has invaded the host. If we can fully understand the mechanisms behind this protection, we can begin to explore ways to undermine it with treatment," said Perrin.

Chagas' disease, typically transmitted to humans by blood-feeding insects, infects an estimated 8 to 11 million people throughout Mexico, and Central and South America. Although it is still rare in the United States, according to the Centers for Disease Control and Prevention (CDC), there are 300,000 people with Chagas' disease living in the United States, most of whom acquired the disease while living in other countries.

The acute phase of Chagas' disease can result in fever or swelling at the site of the insect bite, but many people do not experience symptoms at all. If left untreated, the disease enters an indeterminate phase in which no symptoms are present. During this phase, many people are not aware that they are infected, but approximately 30 percent will eventually develop life-threatening complications of the disease, including enlargement of the digestive tract and/or heart.

This study was funded by grants from the National Institute of Neurological Disorders and Stroke (NINDS), a part of the National Institutes of Health.

Chuenkova MV and PereiraPerrin M. Science Signaling. 2009. (November 17); 2(97), ra74. "Trypanosoma cruzi targets Akt in host cells as an intracellular antiapoptotic strategy." Published online November 17, 2009, doi: 10.1126/scisignal.2000374

About Tufts University School of Medicine

Tufts University School of Medicine and the Sackler School of Graduate Biomedical Sciences at Tufts University are international leaders in innovative medical education and advanced research. The School of Medicine and the Sackler School are renowned for excellence in education in general medicine, special combined degree programs in business, health management, public health, bioengineering and international relations, as well as basic and clinical research at the cellular and molecular level. Ranked among the top in the nation, the School of Medicine is affiliated with six major teaching hospitals and more than 30 health care facilities. The Sackler School undertakes research that is consistently rated among the highest in the nation for its impact on the advancement of medical science.

Source: Tufts University