First (and massive) whole-genome study of IBD in African Americans

In African Americans, the genetic risk landscape for inflammatory bowel disease (IBD) is very different from that of people with European ancestry, according to results of the first whole-genome study of IBD in African Americans. The authors say that future clinical research on IBD needs to take ancestry into account. Findings of the multi-center study, which analyzed the whole genomes of more than 1,700 affected individuals with Crohn’s disease and ulcerative colitis and more than Read more

Emory researchers SNARE new Alzheimer’s targets

Diving deep into Alzheimer’s data sets, a recent Emory Brain Health Center paper in Nature Genetics spots several new potential therapeutic targets, only one of which had been previous linked to Alzheimer’s. The Emory analysis was highlighted by the Alzheimer’s site Alzforum, gathering several positive comments from other researchers. Thomas Wingo, MD Lead author Thomas Wingo and his team -- wife Aliza Wingo is first author – identified the targets by taking a new approach: tracing Read more

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Tweaks to corticosteroids may reduce side effects

Steroid anti-inflammatory drugs such as dexamethasone and prednisone are widely used to treat conditions such as allergies, asthma, autoimmune diseases, cancer – and now, COVID-19. Yet they can have harmful side effects on the skin, bones and metabolism.

The side effects are thought to come from a molecular mechanism that is separate from the anti-inflammatory one, and scientists have envisioned that it may be possible to divide the two. A new paper in PNAS from Emory biochemist Eric Ortlund’s lab sketches out how one potential alternative may work.

Synthetic corticosteroids mimic the action of the stress hormone cortisol; both bind the glucocorticoid receptor (GR) protein. Ortlund’s group obtained structural information on how vamorolone, an experimental drug, sticks to the part of GR that binds hormones.

The American company ReveraGen and Swiss partner Santhera are developing vamorolone for Duchenne muscular dystrophy, but it is possible to envision several other conditions such as ulcerative colitis for which vamorolone or a similar drug could be helpful. Vamorolone is NOT approved by the FDA for Duchenne muscular dystrophy or any other indication.

As far as its interaction with GR, what sets vamorolone apart from conventional corticosteroids is quite subtle: a missing hydrogen bond. This means that GR doesn’t interact as well with various partner proteins, which are needed to turn on genes involved in processes such as metabolism and bone growth.  However, the anti-inflammatory effects result mainly from turning inflammatory and immune system genes off, and those interactions are maintained. More on that distinction here and here.

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Improve old antibiotics rather than discover new ones, BME researchers propose

The resistance of bacteria to antibiotics is a global challenge that has been exacerbated by the financial burdens of bringing new antibiotics to market and an increase in serious bacterial infections as a result of the COVID-19 pandemic.

Biomedical engineering researchers at Georgia Tech and Emory are tackling the problem of antibiotic resistance not by creating new drugs, but by enhancing the safety and potency of ones that already exist.

Aminoglycosides are antibiotics used to treat serious infections caused by pathogenic bacteria like E. coli or Klebsiella.  Bacteria haven’t developed widespread resistance to aminoglycosides, as compared to other types of antibiotics.  These antibiotics are used sparingly by doctors, in part because of the toxic side effects they can sometimes cause.

In research published in the journal PLOS One, Christopher Rosenberg, Xin Fang and senior author Kyle Allison demonstrated that lower doses of aminoglycosides could be used to treat bacteria when combined with specific metabolic sugars.  Low concentrations of antibiotics alone often cannot eliminate dormant, non-dividing bacterial cells, but the researchers hypothesized based on a past study that combining aminoglycosides with metabolites such as glucose, a simple sugar, or mannitol, a sugar alcohol often used as sweetener, could stimulate antibiotic uptake.

The authors tested these treatment combinations against Gram-negative pathogens E. coli, Salmonella and Klebsiella. The results showed that aminoglycoside-metabolite treatment significantly reduced the concentration of antibiotic needed to kill those pathogens. The authors also demonstrated that this treatment combination did not increase bacterial resistance to aminoglycosides and was effective in treating antibiotic-tolerant biofilms, which are bacterial communities that act as reservoirs of infection.

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Galanin: the ‘keep calm and carry on’ hormone?

A few celebrity neuropeptides have acquired a reputation – sometimes exaggerated — and a flavor, corresponding to their functions in the brain.

Oxytocin has the aura of a “cuddle hormone” because of its role in social bonding and reproduction. Endorphins are the body’s natural pain-killers, long thought to be responsible for “runner’s high.” Hypocretin/orexin, missing in narcolepsy, is a stabilizer of wakefulness as well as motivation.

Galanin, studied by Emory neuroscientist David Weinshenker’s lab, is not as flashy as other neuropeptides. While it is accumulating an intriguing track record, galanin appears to play subtly different roles depending on where it is expressed. It is tempting to call galanin the “keep calm and carry on” hormone, but the research on galanin is so complex it’s difficult to pin down.

Graduate student Rachel Tillage and colleagues have a paper this week in Journal of Neuroscience detailing how galanin’s production by one group of neurons in the brainstem confers stress resilience in mice.

This image shows the rough location for the locus coeruleus in the human brain. In mice, production of galanin in the locus coeruleus cushions against stress.

The new paper shows that exercise increases galanin in the locus coeruleus, a region in the brainstem that produces norepinephrine (important for attention, alertness, anxiety and muscle tone). Galanin can provide protection against the anxiety-inducing effects of artificial but very specific locus coeruleus activation by optogenetics.

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Delayed mechanical strain promotes angiogenesis in bone/wound healing

The natural processes of wound or bone healing rely on the growth of new blood vessels, or angiogenesis. If someone breaks a bone, it is standard practice to apply a cast and immobilize the broken bone, so that healing can proceed without mechanical distortion. 

After those initial stages of healing, applying surprising amounts of pressure can encourage angiogenesis, according to a new paper in Science Advances from biomedical engineer Nick Willett’s lab.

“These data have implications directly on bone healing and more broadly on wound healing,” Willett says. “In bone healing or grafting scenarios, physicians are often quite conservative in how quickly patients begin to load the repair site.”

Willett’s lab is part of both Emory’s Department of Orthopedics and the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory, and is based at the Atlanta Veterans Affairs Medical Center.

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Burning fat like a baby

Newborn humans and hibernating mammals have high levels of brown adipose tissue, which they use to generate heat. Adult humans generally don’t have abundant brown adipose tissue, even if they have lots of “white” fat. Increasing brown fat’s activity may be an approach to treat obesity and related metabolic disorders.

Recently researchers identified an enzyme called Them1 (thioesterase superfamily member 1) as a factor that limits heat generation in brown adipose tissue. Emory biochemist Eric Ortlund and his lab showed how part of the Them1 enzyme binds a certain type of lipid molecule, and also how that part of the enzyme anchors the enzyme close to lipid droplets in adipose cells. Former graduate student Matt Tillman, now a postdoc at Duke, was the first author of the new paper in Proceedings of the National Academy of Sciences.

“In this study, we show Them1 contains a lipid sensor module that detects specific lipids within the cell to regulate its activity,” says Tillman.

In brown adipose cells, the lipid-sensing domain of Them1 is needed for localization around lipid droplets

From Tillman et al PNAS (2020)

He and his colleagues showed that a lipid known for its role in cell signaling, lysophosphatidylcholine or LPC, inhibits Them1 activity, which in turn activates thermogenesis in brown adipose tissue. In contrast, other fatty acids that serve as fuel tend to activate Them1. This regulatory system within Them1 allows the cell to sense its metabolic state and decide when to burn or conserve fat.

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Triple play in science communication

Emory BCDB graduate student Emma D’Agostino

We are highlighting Emory BCDB graduate student Emma D’Agostino, who is a rare triple play in the realm of science communication.

Emma has her own blog, where she talks about what it’s like to have cystic fibrosis. Recent posts have discussed the science of the disease and how she makes complicated treatment decisions together with her doctors. She’s an advisor to the Cystic Fibrosis Foundation on patient safety, communicating research and including the CF community in the research process. She’s also working in biochemist Eric Ortlund’s lab on nuclear receptors in the liver:drug targets for the treatment of diabetes and intestinal diseases.

The triple play is this — on her blog, Emma has discussed how she has to deal with antibiotic resistance. Emory Antibiotic Resistance Center director David Weiss’ lab has published a lot on colistin: how it’s a last-resort drug because of side effects, and how difficult-to-detect resistance to it is spreading. Emma has some personal experience with colistin that for me, brought the issue closer. Read more

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Emory plays leading role in landmark HIV prevention study of injectable long-acting cabotegravir

Emory University played a key role in a landmark international study evaluating the safety and efficacy of the long-acting, injectable drug, cabotegravir (CAB LA), for HIV prevention.

The randomized, controlled, double-blind study found that cabotegravir was 69% more effective (95% CI 41%-84%) in preventing HIV acquisition in men who have sex with men (MSM) and transgender women who have sex with men when compared to the current standard of care, daily oral emtricitabine/tenofovir disoproxil fumarate 200 mg and 300 mg (FTC/TDF) tablets.

The study achieved its primary objective of non-inferiority with the difference approaching superiority in favor of cabotegravir, pending final analysis.

The findings were so positive that, during a planned review of study data, an independent Data and Safety Monitoring Board (DSMB) recommended the study results be announced as soon as possible. The study sponsor, the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, agreed with that recommendation.

Emory, through the Emory-CDC HIV Clinical Trials Unit, enrolled 7% of the study’s more than 4,500 worldwide participants at three of its clinical research sites: The Hope Clinic (86 participants) and the Ponce de Leon Center (35 participants) in Atlanta and at the CDC’s Silom Community Clinic in Bangkok, Thailand (203 participants).

“This is a landmark study with a new approach that will change how HIV prevention is being done and will open the field to future interventions,” says Carlos del Rio, MD, the executive associate dean, Emory University School of Medicine at Grady Health System. Del Rio is a member of the study team and the principal investigator at the Ponce de Leon Center.

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‘Genetic doppelgangers:’ Emory research provides insight into two neurological puzzles

An international team led by Emory scientists has gained insight into the pathological mechanisms behind two devastating neurodegenerative diseases. The scientists compared the most common inherited form of amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD) with a rarer disease called spinocerebellar ataxia type 36 (SCA 36).

Both of the diseases are caused by abnormally expanded and strikingly similar DNA repeats. However, ALS progresses quickly, typically killing patients within a year or two, while the disease progression of SCA36 proceeds more slowly over the course of decades. In ALS/FTD it appears that protein products can poison cells in the nervous system. Whether similar protein products exist in SCA36 is not known.

What Zachary McEachin, PhD, and Gary Bassell, PhD, from Emory’s Department of Cell Biology, along with a team of collaborators at Emory, the Mayo Clinic in Jacksonville, Florida, and internationally from Spain and Japan, discovered have provided a new paradigm for thinking about how aberrant protein species are formed.  Regardless of the disparate clinical outcomes between these diseases, this research could broaden the avenue of research toward genetically targeted treatments for such related neurodegenerative diseases.

Their study, published Tuesday in Neuron, provides a guide to types of protein that build up in brain cells in both disorders, and which should be reduced if the new mode of treatment is working in clinical trials.

“We are thinking of these diseases as genetic doppelgängers,” says McEachin, a postdoctoral fellow in Bassell’s lab. “By that, I mean they are genetically similar, but the neurodegeneration progresses differently for each disease. We can use this research to understand each of the respective disorders much better — and hopefully help patients improve their quality of life down the road with better treatments.”

An estimated 16,000 people in the United States have ALS, a progressive neurodegenerative disease that affects nerve cells in the brain and spinal cord. The most common inherited form of ALS/FTD occurs because there is an abnormally expanded repeat of six DNA “letters” stuck into a gene called c9orf72.

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Posted on by Wayne Drash in Neuro, Uncategorized Leave a comment

Emory launches study on COVID-19 immune responses

Emory University researchers are taking part in a multi-site study across the United States to track the immune responses of people hospitalized with COVID-19 that will help inform how the disease progresses and potentially identify new ways to treat it.  The study is funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.

The study – called Immunophenotyping Assessment in a COVID-19 Cohort (IMPACC) – launched Friday. Investigators expect to enroll up to 2,000 individuals who have been hospitalized with the new coronavirus in 10 research locations across the country.

Participants will be followed for up to 12 months after their hospitalization to assess how well they recover and whether they develop durable immunity to the virus.

Nadine Rouphael, associate professor at Emory’s School of Medicine, is leading the investigation as part of NIAID’s Human Immunology Project Consortium (HIPC) and says the study aims to determine how certain immunological measures correspond to or even predict the clinical severity of COVID-19.

“The IMPACC study is a unique opportunity to leverage clinical data and samples with cutting edge technology,” Rouphael says. “By analyzing the immune responses of diverse participants enrolled in the study, we aim to better understand why some cases of COVID-19 worsen while other patients recover.”

As participants recover, investigators will continue evaluating their immune responses to see how they fare: Do they experience lingering symptoms, or do they get long-term protection against the virus? This effort is one of many clinical projects working to better understand how this novel disease affects people differently and determine optimal ways to treat COVID-19.

Researchers will recruit participants within 36 hours of their admission to the hospital and collect blood and nasal swabs throughout their hospitalization, and during follow-up clinic visits after discharge. When possible, researchers will also examine lower airway secretions collected from patients requiring a ventilator for breathing support. Participants can be co-enrolled in other studies, such as those evaluating experimental treatments for COVID-19.

Biologic samples from all study participants will be sent to a number of Core Laboratories for detailed analysis of various aspects of the immune response to the virus that causes COVID-19.

For more information on the U.S. government response to the COVID-19 pandemic, visit www.coronavirus.gov.

Posted on by Wayne Drash in Immunology, Uncategorized Leave a comment

Marcus Lab researchers make key cancer discovery

A new discovery by Emory researchers in certain lung cancer patients could help improve patient outcomes before the cancer metastasizes.

The researchers in the renowned Marcus Laboratory identified that highly invasive leader cells have a specific cluster of mutations that are also found in non-small cell lung cancer patients. Leader cells play a dominant role in tumor progression, and the researchers discovered that patients with the mutations experienced poorer survival rates.

The findings mark the first leader cell mutation signature identified in patients and could prove key in teasing out high-risk patients, allowing oncologists to develop a treatment plan early on before the disease has progressed.

“It has been a lot of fun to see the research go from the basic science side inside the lab to hopefully having an actual clinical impact,” says Brian Pedro, an MD/PhD student in Emory’s Medical Scientist Training Program. “Our data suggest that if you have one or more of these mutations, then we could potentially intervene early and improve patient outcomes.”

Stopping leader cells before they metastasize has long been a goal of researchers at the Winship Cancer Institute. “That is what we strive for as researchers,” Pedro says. “We are optimistic that this could be a promising clinical tool.”

The findings were published in the American Cancer Society’s journal “Cancer.”

The researchers specifically found the novel mutation cluster on chromosome 16q and compared the survival rates of those who had the mutations with those who did not. The results showed the patients who had the mutations had poorer survival rates across all stages.

Pedro says more investigation is needed to figure out why the mutations lead to poorer outcomes. He adds that he hopes the mutation signature can prove useful for cancer types beyond lung cancer.

You can learn more from Pedro’s Tweetstorm.

 

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