Discovery Could Lead to an Exercise Pill

 

Technology Review

 

 

A newly identified hormone acts like a workout, and transforms bad fat into good

 

 

MIT Technology Review, January 16, 2012, by Karen Weintraub  —  Researchers have discovered a natural hormone that acts like exercise on muscle tissue—burning calories, improving insulin processing, and perhaps boosting strength. The scientists hope it could eventually be used as a treatment for obesity, diabetes, and, potentially, neuromuscular diseases like muscular dystrophy.

In a paper published online today by the journal Nature, the scientists, led by Bruce Spiegelman at the Dana-Farber Cancer Institute in Boston, showed that the hormone occurs naturally in both mice and humans. It pushes cells to transform from white fat—globules that serve as reservoirs for excess calories—into brown fat, which generates heat.

Because the hormone is present in both mice and humans, Spiegelman speculates that it may have served as an evolutionary defense against cold by triggering shivering. He named it irisin, after the Greek messenger goddess Iris, who allowed humans to communicate with the gods in Greek mythology, because exercise appears to “talk” to various tissues in the body via irisin.

Mice given irisin lost a few grams in the first 10 days after treatment, the study shows, and certain genes involved in powering the cell were turned on. Irisin also appeared to reduce the damage done by a high-fat diet, protecting mice against diet-induced obesity and diabetes, according to the paper, whose first author is postdoctoral fellow Pontus Boström.

“We are hopeful, though we have no evidence, that this hormone may embody some of the other benefits of exercise, perhaps in the neuromuscular system,” Spiegelman says. If so, it could also be used to treat disorders like muscular dystrophy and muscle wasting.

Researchers still have to figure out how much benefit irisin could provide someone with diabetes or other health problems, says Spiegelman, also a professor of cell biology and medicine at Harvard Medical School. “I’m optimistic,” he says. “I just don’t want to overpromise and underdeliver.”

Harvard Medical School’s Dean Jeffrey Flier, an endocrinologist, says he is quite enthusiastic about the new hormone. The study, he says, “opens up a completely new approach to understanding the links between exercise, body weight, and diabetes.”

Flier believes irisin offers strong therapeutic potential. “Though much remains to be learned about the action of irisin, and its status in humans with various diseases, this work has the potential to be a game-changer in the field of metabolic disease.”

Last month, Spiegelman formed a Boston-based company named Ember Therapeutics to develop his brown-fat research projects, including irisin. The company raised $34 million in series A financing, and is backed by Third Rock Ventures of Boston.

Harvey Lodish, a professor of biology and bioengineering at MIT, and a member of the Whitehead Institute for Biomedical Research, says it may be harder to make irisin into a drug than Spiegelman anticipates. Lodish tried for years to make adiponectin, a hormone he discovered in the mid-1990s, into a similar drug, but never succeeded.

The concentration of both hormones in the blood is already so high that manufacturing enough to make a difference in health is quite challenging, he says. Maybe irisin will be easier to produce, he says, or maybe it could be delivered via gene therapy, in a modified version of the delivery system Spiegelman used in his research—but Lodish is dubious.

However, of Spiegelman’s new research, he says, “It’s very nice, it’s very elegant.”

 

Device Brings $1,000 Genome Within Reach

 

Sequence machine: The Ion Proton Sequencer chip
Life Technologies

 

 

Ion Torrent introduced its new tabletop sequencer at CES this week.

 

 

MIT Technology Review, January 16, 2012, by Erica Westly  —  Thanks to advances in chemistry and software, researchers can soon sequence a human genome for $1,000 in a day.

Back in July, Jonathan Rothberg, CEO of the Connecticut-based biotech company Ion Torrent, predicted that by 2013 his company would develop a chip that could sequence an entire human genome.

This week, the company surpassed that prediction with a new tabletop sequencer called the Ion Proton. The company introduced the device at the Consumer Electronics Show in Las Vegas on Tuesday, although the sequencer is only available to researchers at this point.

At $149,000, the new machine is about three times the price of the Personal Genome Machine, the sequencer that the company debuted about a year ago. But the DNA-reading chip inside it is 1,000 times more powerful, according to Rothberg, allowing the device to sequence an entire human genome in a day for $1,000—a price the biotech industry has been working toward for years because it would bring the cost down to the level of a medical test.

“The technology got better faster than we ever imagined,” Rothberg says. “We made a lot of progress on the chemistry and software, then developed a new series of chips from a new foundry.” The result is a technology progression that has moved faster than Moore’s law, which predicts that microchips will double in power roughly every two years.

Ion Torrent’s semiconductor-based approach for sequencing DNA is unique. Currently, optics-based sequencers, primarily from Illumina, a San Diego-based company, dominate the human genomics field. But, while the optics-based sequencers are generally considered more accurate, these machines cost upwards of $500,000, putting them out of reach for most clinicians. Meanwhile, at Ion Torrent’s price, “you can imagine one in every doctor’s office,” says Richard Gibbs, director of Baylor College of Medicine’s human genome sequencing center in Houston, which will be among the first research centers to receive a Proton sequencer.

The new Ion Torrent sequencer will also allow researchers to buy a chip that sequences only exons, the regions of the genome that encode proteins. Exons only account for about 5 percent of the human genome, according to the National Human Genome Research Institute, but they are where most disease-causing mutations occur, making so-called exome sequencing a faster and potentially cheaper option for many researchers. Although it’s the same price as the genome chip, the Ion Torrent exome chip can sequence two exomes at a time, bringing the per-sequence cost down to $500.

“Some researchers want to sequence single genes, others want to do exomes, and others—for example, cancer researchers—will want to sequence whole genomes, so all three are going to coexist,” says Rothberg. “It’s about finding the right tool for the problem.”

Whether Ion Torrent’s new technology will be enough to make it the dominant supplier of these tools remains to be seen. A day after the company debuted the Proton sequencer, Illumina also announced that it, too, had reached the $1,000 genome milestone.

“It’s a volatile field, and there’s no sentiment to keep researchers from switching to new technologies,” says Gibbs. Still, Ion Torrent clearly has the price advantage. For researchers who already have Illumina’s latest sequencer, the price to upgrade will be only $50,000, but the retail price will be $740,000, which will likely scare off most newcomers.