Science
Fighting Malaria, With a Little Help from Bacteria
Posted on by Dr. Francis Collins
Caption: Anopheles female blood feeding and Plasmodium falciparum eggs in Anopheles mosquito midguts.
Credit: Image courtesy of Jose Luis Ramirez, Laboratory of Malaria and Vector Research, NIAID, NIH
It turns out that one of the most innovative and effective strategies to fight malaria might involve harnessing a bacterium called Wolbachia. This naturally occurring genus of bacteria infects many species of insects, including mosquitoes. The reason this is important is that Wolbachia-infected mosquitoes become resistant to the parasite Plasmodium falciparum, which causes some 219 million cases of malaria worldwide and more than 660,000 deaths [1]. Wouldn’t it be amazing if Wolbachia-infected mosquitoes blocked the transmission of malaria?
Unfortunately, Wolbachia don’t normally pass from generation to generation in Anopheles, the mosquitoes that spread malaria. But that hurdle has now been overcome.
Fishing for Answers in Human Disease
Posted on by Dr. Francis Collins
Caption: Researcher Zhaoxia Sun, at Yale, uses the zebrafish to study Polycystic Kidney Disease, which affects more than 600,000 Americans. Mutations in the zebrafish vhnf1 gene, and its human counterpart, cause cysts in both zebrafish and human kidneys (as shown by the large “bubble” seen in the mutant fish). [3]
Credit: Zhoaxia Sun, Biological & Biomedical Sciences, Yale University
Just last month, an international team of scientists—funded in part by NIH—published the entire genetic code of the zebrafish [1]. This is a vital resource for understanding human health and disease. How does the genetic blueprint of a fish help us or accelerate drug discovery? Well, it turns out that more than 75% of the genes that have been implicated in human diseases have counterparts in the zebrafish. So, if we discover a mutation in a human, we can make the corresponding mutation in the zebrafish gene—and often get a pretty good idea of how the gene works, how the mutation causes havoc, and how it causes disease in humans. We can even use the zebrafish to test potential drug candidates, to see whether they can alter or fix the symptoms before moving on to mice or humans.
More Beta Cells, More Insulin, Less Diabetes
Posted on by Dr. Francis Collins
Caption: Betatrophin, a natural hormone produced in liver and fat cells, triggers the insulin-producing beta cells in the pancreas to replicate
Credit: Douglas Melton and Peng Yi
Type 2 diabetes (T2D) has arguably reached epidemic levels in this country; between 22 and 24 million people suffer from the disease. But now there’s an exciting new development: scientists at the Harvard Stem Cell Institute have discovered a hormone that might slow or stop the progression of diabetes [1].
T2D is the most common type of diabetes, accounting for about 95% of cases. The hallmark is high blood sugar. It is linked to obesity, which increases the body’s demand for more and more insulin. T2D develops when specific insulin-producing cells in the pancreas, called beta cells, become exhausted and can’t keep up with the increased demand. With insufficient insulin, blood glucose levels rise. Over time, these high levels of glucose can lead to heart disease, stroke, blindness, kidney disease, nerve damage, and even amputations. T2D can be helped by weight loss and exercise, but often oral medication or insulin shots are ultimately needed.
Spiny Worm Inspires Next-Gen Band-Aid
Posted on by Dr. Francis Collins
Caption: Artist rendition of spiny headed worm │The adhesive patch with microneedles that swell
Source: The Karp Lab, Brigham and Women’s Hospital
Inspiration can come from some pretty strange sources. Case in point: a new adhesive Band-Aid inspired by Pomphorhynchus laevis, a spiny-headed worm that lives in the intestines of fish. The parasitic worm pokes its tiny, spiny, cactus shaped head through the intestinal lining and then inflates its head with fluid to stay anchored.
Using the same principle, the team at the Boston-based Brigham and Women’s Hospital created an adhesive patch with needles that swell up when they get wet, interlocking with the tissue. When this sticky patch is applied to anchor skin grafts that have just been placed over an area of injury or burn, it is three times stronger than surgical staples—and it causes less damage to soft tissues. Because it penetrates about one fourth the depth of staples, it should also be less painful to remove.
An Evolving App for Genetic Tests
Posted on by Dr. Francis Collins
Source: National Human Genome Research Institute, NIH
We all hope for health care in the genomic era to become as easy and personal as a smartphone app. And perhaps at some point it will be. At some medical centers, electronic health records already include a list of patients’ genetic variations that might trigger harmful drug reactions and send ‘pop-up’ alerts to warn the physician or pharmacist. This is just the tip of the iceberg, but it’s a harbinger of things to come. Our big challenge is to translate all the new discoveries and data from the genome project into a format that physicians and other health care providers can use to improve health.
To bridge that transition from discovery to diagnostics and treatments, the NIH launched the Genetic Testing Registry (GTR) last year. There are hundreds of genetic testing companies, thousands of genetic tests for thousands of diseases, and some diseases have more than 20 names. What a challenge for providers to sort through! GTR is becoming a central repository of all the genetic tests available, and therefore greatly simplifies this search. It’s a vital resource, as providers can’t be expected to know all the diseases and genes or to keep tabs on the growing number of tests.
DNA’s Double Anniversary
Posted on by Dr. Francis Collins
April 25 is a very special day. In 2003, Congress declared April 25th DNA Day to mark the date that James Watson and Francis Crick published their seminal one-page paper in Nature [1] describing the helical structure of DNA. That was 60 years ago. In that single page, they revealed how organisms elegantly store biological information and pass it from generation to generation; they discovered the molecular basis of evolution; and they effectively launched the era of modern biology.
But that’s not all that’s special about this date. It was ten years ago this month that we celebrated the completion of all of the original goals of the Human Genome Project (HGP), which produced a reference sequence of the 3 billion DNA letters that make up the instruction book for building and maintaining a human being. The $3 billion, 13-year project involved more than 2,000 scientists from six countries. As the scientist tasked with leading that effort, I remain immensely proud of the team. They worked tirelessly and creatively to do something once thought impossible, never worrying about who got the credit, and giving all of the data away immediately so that anyone who had a good idea about how to use it for human benefit could proceed immediately. Biology will never be the same. Medical research will never be the same.
Promising Treatment for New Human Coronavirus
Posted on by Dr. Francis Collins
Caption: Transmission electron micrograph of novel coronavirus
Credit: Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, NIH
In Fall 2012 a new coronavirus appeared on the global public health radar. The virus has caused 17 cases of severe respiratory disease in the Middle East and Europe, and 11 of these people died. This new virus attracted immediate attention because of the high fatality rate—and because it was in the same family as the virus that caused the global outbreak of severe acute respiratory syndrome (SARS) in 2003, which sickened more than 8,000 people.
Close-up of Enzyme Linked to Rapid Aging Disease
Posted on by Dr. Francis Collins
Caption: Children with HGPS
Source: The Progeria Research Foundation
I’d like to tell you about a rare genetic disease that’s very close to my heart: Hutchinson-Gilford progeria syndrome, also called progeria. Though you may not recognize the name, you may well have seen pictures of children with this fatal premature aging disease. By 18-24 months, apparently healthy babies stop growing and begin to lose their hair. They develop wrinkled skin and joint problems and they suffer many other conditions of old age. Though their mental development is entirely normal, they often die of heart disease or stroke by age 12 or 13.
A decade ago, my research lab helped discover the cause of progeria: a mutation in the lamin-A gene [1]. Just a single letter substitution in the genetic code (C to T) creates a toxic version of the protein. The abnormal protein is missing a segment, and is no longer digestible by an enzyme called ZMPSTE24—essentially a molecular scissors. Without that final snip, the lamin-A protein causes molecular havoc.
Shining a Bright Light on Cocaine Addiction
Posted on by Dr. Francis Collins
Caption: Optogenetic stimulation using laser pulses lights up the prelimbic cortex
Source: Courtesy of Billy Chen and Antonello Bonci
Wow—there is a lot of exciting brain research in progress, and this week is no exception. A team here at NIH, collaborating with scientists at the University of California in San Francisco, delivered harmless pulses of laser light to the brains of cocaine-addicted rats, blocking their desire for the narcotic.
If that sounds a bit way out, I can assure you the approach is based on some very solid evidence suggesting that people—and rats—are more vulnerable to addiction when a region of their brain in the prefrontal cortex isn’t functioning properly. Brain imaging studies show that rat and human addicts have less activity in the region compared with healthy individuals; and chronic cocaine use makes the problem of low activity even worse. The prefrontal cortex is critical for decision-making, impulse control, and behavior; it helps you weigh the negative consequences of drug use.
The Brain: Now You See It, Soon You Won’t
Posted on by Dr. Francis Collins
A post mortem brain is a white, fatty, opaque, three-pound mass. Traditionally scientists have looked inside it by cutting the brain into thin slices, but the relationships and connections of the tens of billions of neurons are then almost impossible to reconstruct. What if we could strip away the fat and study the details of the wiring and the location of specific proteins, in three dimensions? An NIH funded team at Stanford University has done just that, developing a breakthrough method for unmasking the brain.
Using a chemical cocktail, they infuse the brain with a hydrogel that locks in the brain’s form and structure in a type of matrix. Then the fatty layer that coats each nerve cell is stripped away, leaving a transparent brain (check out the transparent mouse brain below). The hydrogel prevents the brain from disintegrating into a puddle once the fat is gone.
Caption: CLARITY transforms a mouse brain at left into a transparent but still intact brain at right. Shown superimposed over a quote from the great Spanish neuroanatomist Ramon y Cajal.
Credit: Kwanghun Chung and Karl Deisseroth, Howard Hughes Medical Institute/Stanford University
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