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.
Researchers study confluence of multidrug resistance and hypervirulence among Klebsiella pneumoniae
New “hypervirulent” strains of the bacterium Klebsiella pneumoniae have emerged in healthy people in community settings, prompting a National Institutes of Health research group to investigate how the human immune system defends against infection. After exposing the strains to components of the human immune system in a laboratory “test tube” setting, scientists found that some strains were more likely to survive in blood and serum than others, and that neutrophils (white blood cells) are more likely to ingest and kill some strains than others. The study, published in mBio, was led by researchers at NIH’s National Institute of Allergy and Infectious Diseases (NIAID).
“This important study is among the first to investigate interaction of these emergent Klebsiella pneumoniae strains with components of human host defense,” Acting NIAID Director Hugh Auchincloss, M.D., said. “The work reflects the strength of NIAID’s Intramural Research Program. Having stable research teams with established collaborations allows investigators to draw on prior work and quickly inform peers about new, highly relevant public health topics.”
A human neutrophil (red) containing ingested Klebsiella pneumoniae (purple).
High levels of some minerals and metals in environmental water supplies may increase the risk of nontuberculous mycobacteria (NTM) pulmonary infections in people with cystic fibrosis, according to a new study from the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health. The study, appearing in Environmental Epidemiology, found the presence of the metals molybdenum and vanadium along with sulfate—a collection of mineral salts—in the U.S. municipal water system was associated with an increased incidence of NTM pulmonary infections, the leading cause of drinking-water associated illnesses.
Prior studies have shown that certain environmental conditions, including the presence of trace metals, likely contribute to a higher abundance of NTM in the water. Two of the most common forms of NTM bacteria in the U.S. are Mycobacterium avium complex (MAC) and M. abscessus. Both are linked to chronic lung infections in people with cystic fibrosis and other lung diseases. More than 35,000 people in the U.S. have cystic fibrosis, which causes the body to produce thick mucus, causing lung damage and trapping bacteria, increasing the likelihood of lung infection. This study measured whether the concentration of metals and minerals in the water had any influence on the probability of MAC and M. abscessus infection in people with cystic fibrosis.
A magnified view of a petri dish culture plate with cultivated colonies of the bacterium Mycobacterium avium. Color effects have been added to image for visual interest.
NIH-supported, international study underscores importance of research of diverse populations
A gene variant found almost exclusively in the genomes of people of African ancestry increases the risk of developing Parkinson’s disease, according to an international study of nearly 198,000 participants with this genetic background. Published in The Lancet Neurology, the study results suggest the risk may be linked to a variant in the gene encoding β-glucocerebrosidase (GBA1), a protein known to control how cells in the body recycle proteins.
The study was led by scientists at the National Institutes of Health; the University College, London; and the University of Lagos, Nigeria. Although more research is needed to understand the role of environmental and other factors in these populations, the scientists found that those who carry one copy of the gene are about 1.5 times more likely to have Parkinson’s disease than those who have no copies whereas those who carry two copies are about 3.5 times more likely.
“To effectively treat Parkinson’s and truly any disease, we must study diverse populations to fully understand what the drivers and risk factors are for these disorders,” said Andrew B. Singleton, Ph.D., director, NIH Intramural Center for Alzheimer’s Related Dementias (CARD) and a study author. “These results support the idea that the genetic basis for a common disease can differ by ancestry, and understanding these differences may provide new insights into the biology of Parkinson’s disease.”
Scientists discovered a gene variant, found almost exclusively in the genomes of individuals of African ancestry, that increases the risk of having Parkinson’s disease. Image created on BioRender.com, courtesy of Singleton lab
New sequence reveals genomic factors in fertility, including sperm production
An international research team has generated the first truly complete sequence of a human Y chromosome, the final human chromosome to be fully sequenced. The new sequence, which fills in gaps across more than 50% of the Y chromosome’s length, uncovers important genomic features with implications for fertility, such as factors in sperm production. The study, led by the Telomere-to-Telomere (T2T) Consortium, a team of researchers funded by the National Human Genome Research Institute (NHGRI), part of the National Institutes of Health, was published today in Nature.
The Y chromosome, along with the X chromosome, is often discussed for its role in sexual development. While these chromosomes play a central role, the factors involved in human sexual development are spread across the genome and very complex, giving rise to the array of human sex characteristics found among male, female and intersex individuals. These categories are not equivalent to gender, which is a social category. Additionally, recent work demonstrates that genes on the Y chromosome contribute to other aspects of human biology, such as cancer risk and severity.
When researchers completed the first human genome sequence 20 years ago, gaps were left in the sequences of all 24 chromosomes. However, unlike the small gaps sprinkled across the rest of the genome sequence — gaps that the T2T Consortium filled in last year — over half of the Y chromosome’s sequence remained a mystery.
The human Y chromosome is the final human chromosome to be fully sequenced. The new sequence, which fills in gaps across more than 50% of the Y chromosome’s length, uncovers important genomic features with implications for fertility, such as factors in sperm production.
A microscopy image created by National Institutes of Health researchers is part of the “Life Magnified” stamp panel issued today by the United States Postal Service (USPS). The NIH zebrafish image, which was taken to understand lymphatic vessel development in the brain, merges 350 individual images to reveal a juvenile zebrafish with a fluorescently tagged skull, scales and lymphatic system.
“Zebrafish are used as a model for typical and atypical human development. It is surprising how much we have in common with zebrafish,” said Diana W. Bianchi, director of NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), which generated the image. “NIH research affects our lives every day. My hope is that this postage stamp will help spur conversations and appreciation for the importance of basic science research.”
The image was taken by NICHD’s Daniel Castranova, an aquatic research specialist, with assistance from former trainee Bakary Samasa. The research was conducted in the Section on Vertebrate Organogenesis, led by principal investigator Brant Weinstein, Ph.D. The lab is devoted to understanding mechanisms guiding the formation of blood and lymphatic vessels. The image also received top honor in the 46th annual Nikon Small World Photomicrography Competition in 2020.
NIH researchers created the zebrafish microscopy image as part of their research on lymphatic vessel development in the brain.
NIH and CDC study finds telehealth associated with increased likelihood of receiving evidence-based standard of care
In 2021, an estimated 2.5 million people aged 18 years or older in the U.S. had opioid use disorder in the past year, yet only 1 in 5 of them (22%) received medications to treat it, according to a new study. Some groups were substantially less likely to receive medication for opioid use disorder, including Black adults, women, those who were unemployed, and those in nonmetropolitan areas.
Published today in JAMA Network Open, this study was a collaborative effort between researchers at the National Institute on Drug Abuse (NIDA), part of the National Institutes of Health, and the National Center for Injury Prevention and Control, a part of the Centers for Disease Control and Prevention (CDC). The findings highlight that evidence-based medications for people with opioid use disorder — including buprenorphine, methadone, and naltrexone — continue to be vastly underused.
“Medications for opioid use disorder are safe and effective. They help sustain recovery and prevent overdose deaths,” said Nora Volkow, M.D., director of the National Institute on Drug Abuse. “Failing to use safe and lifesaving medications is devastating for people denied evidence-based care. What’s more, it perpetuates opioid use disorder, prolongs the overdose crisis, and exacerbates health disparities in communities across the country.”
Lawrence A. Tabak, D.D.S., Ph.D., acting director for the National Institutes of Health, has named Jeanne M. Marrazzo, M.D., as director of NIH’s National Institute of Allergy and Infectious Diseases (NIAID). Dr. Marrazzo is currently the director of the Division of Infectious Diseases at the University of Alabama at Birmingham. She is expected to begin her role as NIAID Director in the fall. NIAID conducts and supports basic and applied research to better understand, treat and ultimately prevent infectious, immunologic and allergic diseases.
“Dr. Marrazzo brings a wealth of leadership experience from leading international clinical trials and translational research, managing a complex organizational budget that includes research funding and mentoring trainees in all stages of professional development,” said Dr. Tabak. “I look forward to welcoming Dr. Marrazzo to the NIH leadership team. I also want to extend my gratitude to Hugh Auchincloss, Jr., M.D., for serving as acting director of NIAID after long-time director Anthony S. Fauci, M.D., stepped down in December 2022.”
As NIAID director, Dr. Marrazzo will oversee NIAID’s budget of $6.3 billion, which supports research to advance the understanding, diagnosis and treatment of infectious, immunologic and allergic diseases. NIAID supports research at universities and research organizations around the United States and across NIAID’s 21 laboratories, including the Vaccine Research Center on NIH’s main campus in Bethesda, Maryland, and the Rocky Mountains Laboratories in Hamilton, Montana. NIAID also has a unique mandate to respond to emerging and re-emerging public health threats at home and abroad. The NIAID research response to outbreaks of infectious diseases, from HIV to Ebola to COVID-19, has led to new therapies, vaccines, diagnostic tests and other technologies.
NIH study finds radiation shows strongest association, less for surgery and endocrine treatments
Women diagnosed and treated for breast cancer have increased biological aging compared to women who remain free of breast cancer, according to a new study by researchers at the National Institutes of Health and their collaborators. Among women diagnosed with breast cancer, the association with faster biological aging was most pronounced for those who received radiation therapy, while surgery showed no association with biological aging. This finding suggests that developing cancer is not what increases the aging effect.
“Of the three treatment classes we looked at, radiation therapy had the strongest associations with the biologic age measures assessed in the study,” noted Jack Taylor, M.D., Ph.D., the senior author on the paper who is an Emeritus Scientist at NIEHS. “The increases can be detected years after treatment.”
Biological age reflects a person’s cell and tissue health, and it differs from chronological age. To measure biological age, the researchers studied 417 women who had blood samples collected at two time points about eight years apart. About half of the women studied were selected because they had developed breast cancer during that time span. The participants are enrolled in the Sister Study, a research effort that seeks to identify environmental risk factors for breast cancer risk and other health conditions, led by the National Institute of Environmental Health Sciences (NIEHS), part of NIH.
One of the first human studies on how mitochondrial function impacts immune cells to guide future treatments
In a new study, National Institutes of Health (NIH) researchers found that altered B cell function in children with mitochondrial disorders led to a weaker and less diverse antibody response to viral infections. The study, published in Frontiers in Immunology, was led by researchers at the National Human Genome Research Institute (NHGRI), who analyzed the gene activities of immune cells in children with mitochondrial disorders and found that B cells, which produce antibodies to fight viral infections, are less able to survive cellular stress.
“Our work is one of the first examples to study how B cells are affected in mitochondrial disease by looking at human patients,” said Eliza Gordon-Lipkin, M.D., assistant research physician in NHGRI’s Metabolism, Infection and Immunity Section and co-first author of the paper.
Mitochondria are important components of nearly every cell in the body because they convert food and oxygen into energy. Genomic variants in more than 350 genes have been linked to mitochondrial disorders with varied symptoms depending on which cells are affected.
“For children with mitochondrial disorders, infections can be life threatening or they can worsen the progression of their disorder,” said Peter McGuire, M.B.B.Ch., NHGRI investigator, head of the Metabolism, Infection and Immunity Section and senior author of the study. “We wanted to understand how immune cells differ in these patients and how that influences their response to infections.”
Mitochondria convert food and oxygen into energy. Genomic variants in more than 350 genes have been linked to mitochondrial disorders.
Finding could point toward more effective treatments that could potentially prevent cancer relapse.
A new study suggests that cells preparing to divide can reverse this process and return to a resting state, challenging long-held beliefs about cell division. If interrupted early in their preparation to divide, cells were able to halt the division process, known as mitosis. The finding, led by researchers at the National Cancer Institute (NCI), part of the National Institutes of Health, and reported July 5, 2023, in Nature, could point toward more effective treatments to interrupt the process by which cancer cells divide quickly and spread.
When cells receive growth-promoting signals, called mitogens, they enter the cell cycle —synthesize new copies of their DNA in a series of steps that culminate in cell division. Scientists have long thought that the preparatory stage of this cycle includes a point after which cells cannot halt the process. Researchers believed that after this “point of no return,” growth signals are no longer needed to drive cells to divide.
In the new study, scientists at NCI’s Center for Cancer Research captured videos of thousands of cells undergoing mitosis and watched what happened to those cells when mitogens were withdrawn. About 15 percent of the cells exited the cell cycle and returned to a resting state. What those cells had in common was that they hadn’t been as far along as others in the cycle when they stopped receiving growth-promoting signals. In experiments with many different kinds of cells, researchers found that all types of cells were capable of exiting the cell cycle if it was early enough.
