Research advances from the National Institutes of Health (NIH) Intramural Research Program (IRP) often make headlines. Read the news releases that describe our most recent findings:
Whether you’re shedding pounds with the help of effective new medicines, slimming down after weight loss surgery or cutting calories and adding exercise, there will come a day when the numbers on the scale stop going down, and you hit the dreaded weight loss plateau.
In a recent study, Kevin Hall, a researcher at the National Institutes of Health who specializes in measuring metabolism and weight change, looked at when weight loss typically stops depending on the method people were using todrop pounds. He broke down the plateau into mathematical models using data from high-quality clinical trials of different ways to lose weight to understand why people stop losing when they do. The study published Monday in the journal Obesity.
Kinesin family member 5A (KIF5A), a gene previously linked to two rare neurodegenerative disorders, has been definitively connected to amyotrophic lateral sclerosis (ALS) by an international team from several of the world’s top ALS research labs. The findings identify how mutations in KIF5A disrupt transport of key proteins up and down long, threadlike axons that connect nerve cells between the brain and the spine, eventually leading to the neuromuscular symptoms of ALS.
The discovery, published in the March 21, 2018, issue of Neuron, was led by Bryan Traynor, M.D., Ph.D., of the Intramural Research Program of the National Institute on Aging (NIA) at the National Institutes of Health and John Landers, Ph.D., of the University of Massachusetts Medical School, Worcester, with key funding support from the NIA, the National Institute of Neurological Disorders and Stroke (NINDS) at NIH, and several public and private sector organizations. Genetic data collected by teams of scientists worldwide contributed to the project.
It took a comprehensive, collaborative effort to analyze a massive amount of genetic data to pin down KIF5A as a suspect for ALS, also known as Lou Gehrig’s disease. To zero in on KIF5A, the NIH team performed a large-scale genome-wide association study, while the University of Massachusetts team concentrated on analyzing rare variants in next generation sequence data. Over 125,000 samples were used in this study, making it by far the largest such study of ALS performed to date.
An international team of ALS researchers has proven that mutations in the neuronal transport gene KIF5A are associated with ALS.
Marijuana impairment cited most in study of recent high school graduates
Roughly a third of recent high school graduates have ridden in a motor vehicle with a substance-impaired driver, according to a study by researchers at the National Institutes of Health and other institutions. The study found that during the first two years after high school graduation, 23 percent of young adults had ridden with a marijuana-impaired driver at least once, while 20 percent had ridden with an alcohol-impaired driver, and 6 percent had ridden with a driver impaired by glue or solvents or harder, illicit drugs, such as amphetamines, opioids, cocaine.
The analysis was conducted by researchers at NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD); Colorado State University, Fort Collins; the Colorado School of Public Health, Denver; and Yale University, New Haven, Connecticut. Their results appear in the Journal of Studies on Alcohol and Drugs.
The authors analyzed data from NICHD’s NEXT Generation Health Study, a seven-year study of more than 2,700 U.S. adolescents starting at grade 10. Its goal is to identify the social, behavioral and genetic factors linked to health and healthy behaviors. Along with NICHD, funding for the NEXT Generation Health Study was provided by NIH’s National Heart, Lung, and Blood Institute and the Maternal and Child Health Bureau of the Health Resources and Services Administration.
Scientists have discovered a human antibody that protected mice from infection with the deadliest malaria parasite, Plasmodium falciparum. The research findings provide the basis for future testing in humans to determine if the antibody can provide short-term protection against malaria, and also may aid in vaccine design. Investigators at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, led the research with colleagues at the Fred Hutchinson Cancer Research Center in Seattle. Currently, there is no highly effective, long-lasting vaccine to prevent malaria, a mosquito-spread disease that causes some 430,000 deaths each year, primarily among young children in sub-Saharan Africa.
The research team isolated the antibody, called CIS43, from the blood of a volunteer who had received an experimental vaccine made from whole, weakened malaria parasites (PfSPZ Vaccine-Sanaria). The volunteer was later exposed to infectious malaria-carrying mosquitoes under carefully controlled conditions and did not become infected. In two different models of malaria infection in mice, CIS43 was highly effective at preventing malaria infection. If confirmed through additional studies in people, CIS43 could be developed as a prophylactic measure to prevent infection for several months after administration, the researchers say. Such a prophylactic antibody could be useful for tourists, health care workers, military personnel or others who travel to areas where malaria is common. Moreover, if the antibody prevented malaria infection for up to six months, it might be combined with antimalarial drugs and be deployed as part of mass drug administration efforts that potentially could eliminate the disease in malaria-endemic regions.
Promising concept may lead to an alternative to antibiotics
Researchers are developing a promising alternative to antibiotic treatment for infections caused by Klebsiella pneumoniae bacteria resistant to carbapenem antibiotics. The approach uses antibodies to target the K. pneumoniae protective capsule polysaccharide, allowing immune system cells called neutrophils to attack and kill the bacteria. The early stage, in vitro research was conducted by scientists at the National Institute of Allergy and Infectious Diseases’ (NIAID) Rocky Mountain Laboratories and the New Jersey Medical School-Rutgers University.
Klebsiella bacteria cause about 10 percent of all hospital-acquired infections in the United States. A carbapenem-resistant K. pneumoniae strain known as multilocus sequence type 258 (ST258) is one of the antibiotic-resistant organisms labeled an urgent threat by the Centers for Disease Control and Prevention. ST258 is particularly concerning because it is resistant to most antibiotics. It is a significant cause of mortality among people with bloodstream infections.
Study of flies suggests neurodegenerative disorders may speed up aging process
To understand the link between aging and neurodegenerative disorders such as Alzheimer’s disease, scientists from the National Institutes of Health compared the genetic clocks that tick during the lives of normal and mutant flies. They found that altering the activity of a gene called Cdk5 appeared to make the clocks run faster than normal, and the flies older than their chronological age. This caused the flies to have problems walking or flying later in life, to show signs of neurodegeneration, and to die earlier.
“We tried to untangle the large role aging appears to play in some of the most devastating neurological disorders,” said Edward Giniger, Ph.D., senior investigator at the NIH’s National Institute of Neurological Disorders and Stroke and the senior author of the study published in Disease Models & Mechanisms. “Our results suggest that neurodegenerative disorders may accelerate the aging process.”
On average, the normal flies in this study lived for 47 days. To create a genetic clock, Dr. Giniger’s team measured the levels of every gene encoded in messenger RNA molecules from cells from the heads and bodies of flies at 3, 10, 30, and 45 days after birth. This allowed the researchers to use advanced analysis techniques to search for the genes that seemed to be sensitive to aging, and create a standard curve, or timeline, that described the way they changed.
Monoclonal antibodies (mAbs) — preparations of a specific type of antibody designed to bind to a single target — have shown promise in the fight against cancer and autoimmune diseases. They also may play a critical role in future battles against emerging infectious disease outbreaks, according to a new article by scientists from the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. The article is published online this week by the New England Journal of Medicine and outlines the potential uses for mAbs as treatments for infectious diseases and as a prevention tool for protecting individuals at risk of infection and slowing disease outbreaks.
The article, written by NIAID Director Anthony S. Fauci, M.D., and colleagues Hilary D. Marston, M.D., M.P.H., and Catharine I. Paules, M.D., highlights the research advances that could allow for rapid, strategic deployment of mAbs to prevent and treat emerging infectious diseases and, potentially, alter the course of epidemics.
Ebola virus particles (red) on a larger cell. ZMAPP, a potential treatment for Ebola, includes a cocktail of monoclonal antibodies.
Familial human prion diseases are passed within families and are associated with 34 known prion protein mutations. To determine whether three of the unstudied mutations are transmissible, scientists from the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, exposed research mice to brain samples from three people who died from a familial prion disease. After observing the mice for about two years, they found two of the mutations, Y226X and G131V, are transmissible.
Perhaps more interesting, the Y226X patient sample had previously been preserved in formaldehyde for three days, embedded in wax, and dried on glass specimen slides for several years before being rehydrated for the study. Yet, the sample infected four of eight mice.
The finding illustrates the hardiness of prion infectivity and the potential risks associated with prion transmission, potentially through surgery, blood transfusion or tissue donation. Samples for the other two mutations studied were taken from frozen brain tissue that was thawed.
Researchers can predict variants’ impact, recall participants to test predictions
Databases such as the 1000 Genomes Project and the Exome Aggregation Consortium (ExAC) harbor large numbers of genotypes (an individual’s collection of genes). Until now, it has been difficult for researchers to re-contact individuals with genotypes of interest and investigate the health consequences of their genes and gene variants. To address this challenge, National Institutes of Health and Inova Health System researchers are launching The Genomic Ascertainment Cohort (TGAC), a two-year pilot project that will allow them to recall genotyped people and examine the genes and gene variants’ influence on their phenotypes, an individual’s observable traits, such as height, eye color or blood type.
The project reverses a long-standing research paradigm of examining a person’s traits or symptoms and then searching for genes or gene variants that cause or contribute to them. NIH will establish a new database of 10,000 human genomes and exomes, the 1-2 percent of the genome that contains protein-coding genes. Once the database is established, NIH and Inova researchers will predict conditions that specific genes or gene variants might produce and test those predictions by re-examining individuals who donated their DNA sequence information to the database. TGAC will be based in the Washington, D.C., area and only people who’ve expressly given consent to be re-contacted will participate in TGAC.
“We’re trying to advance science in a new, creative and slightly radical way,” said Leslie Biesecker, M.D., TGAC co-organizer and chief of the Medical Genomics and Metabolic Genetics Branch at NIH’s National Human Genome Research Institute (NHGRI). “Our goal is to determine what genes and gene variants do. We’re especially interested in using this as a platform to test our ability to predict phenotype from genotype – one of the key underpinnings of predictive genomic medicine.” NHGRI will host the database and administer the program.
Study in mice suggests that experimental drug may be effective against mountain sickness and other polycythemias
Researchers at the National Institutes of Health have cured mice with Chuvash polycythemia, a life-threatening disorder that involves the overproduction of red blood cells. They treated the mice using Tempol, an experimental drug being studied for treatment of diabetes, cancer and other diseases. The findings offer hope that Tempol or a similar drug may treat polycythemias that affect humans, such as mountain sickness—a serious blood complication experienced in low-oxygen, high-altitude settings. The study appears in The Journal of Clinical Investigation.
Chuvash polycythemia is a rare, inherited disorder that is endemic to the Chuvash Republic of Russia, though it does occur in other parts of the world. NIH studies rare diseases not only to help the people who have them, but also to gain insight into gene functions that may benefit people with more common conditions. Complications of Chuvash polycythemia include blood clots and cerebral hemorrhage. The condition results from a genetic mutation that makes people unable to break down hypoxia inducible factor 2α (HIF2α), a protein that helps stimulate red blood cell production. The inability to degrade HIF2α leads to higher red cell production, even under high-oxygen conditions.
Natural history investigation will deploy latest advances to identify biomarkers, targets for early therapy
A new clinical study led by the National Eye Institute (NEI), part of the National Institutes of Health, will follow 500 people over five years to learn more about the natural history of early age-related macular degeneration (AMD). By using the latest technologies to visualize structures within the eye and measure their function, researchers hope to identify biomarkers of disease progression, well before it advances to late-stage disease and causes vision loss. AMD is the leading cause of vision impairment and blindness among people age 50 and older in the United States.
“The findings will contribute to our understanding of the underlying biology driving the transition from early to late-stage disease so that therapies can be developed to halt its progression,” said the study’s lead investigator, Emily Y. Chew, M.D., deputy clinical director at NEI and director of the NEI Division of Epidemiology and Clinical Applications. “Treatments that halt the disease at its early stage would have an enormous public health impact.”
Fundus photo shows giraffe-like macular pattern in the retina of a person with reticular pseudodrusen.
