Molecular picture of how antiviral drug molnupiravir works

A cryo-EM structure showing how the antiviral drug molnupiravir drug Read more

Straight to the heart: direct reprogramming creates cardiac “tissue” in mice

New avenues for a quest many cardiologists have pursued: repairing the damaged heart like patching a Read more

The future of your face is plastic

An industrial plastic stabilizer becomes a skin Read more

inflammation

The future of your face is plastic

Prolific drug discoverer and repurposer Jack Arbiser is at it again. Arbiser, an Emory dermatologist, has identified a new (but old) compound as a treatment for rosacea, a common skin condition involving redness and visible blood vessels on the face. Severe rosacea can lead to itching, pain, or thickening of the skin.

The compound is remarkable for two reasons: it is the same as Irganox 1010, an antioxidant plastic stabilizer used in industry for years, and it is a proteasome inhibitor.

The proteasome is the cell’s garbage disposal, and many kinds of proteins get tagged and thrown into it. Interfering with the disposal inhibits the inflammatory NFkB pathway. Oncologists may be familiar with the proteasome inhibitor bortezomib (a blockbuster drug known commercially as Velcade), used to treat multiple myeloma.

Arbiser has founded a company called Accuitis to develop the compound, called ACU-D1. Accuitis was funded by the Georgia Research Alliance. Accuitis’ web site notes that the compound “has the advantage of extensive toxicology testing in multiple animal species, as well as a safe record of human exposure for over 30 years.”

“ACU-D1 is a cream that works through a new mechanism of action that no current rosacea medications work through,” Arbiser told Dermatology Times. “Given the fact that there are no truly great treatments for rosacea, we are hoping that in the future our compound will be a first-in-class drug and become first-line therapy for rosacea.”

The results of a clinical trial for ACU-D1, conducted at the University of Louisville in Kentucky and Forefront Dermatology in San Antonio, were recently published in Journal of Drug in Dermatology.

This was a first-in-human study with 40 participants, lasting 12 weeks. It was not powered for a pivotal evaluation of ACU-D1’s efficacy. However, the drug showed a pronounced effect on people with severe rosacea. The trial used a Canfield imaging system imaging as a way of measuring skin irritation objectively, separately from the opinions of the investigators.

Canfield imaging of the face. From left to right: baseline, week 4, week 12

The drug appears to take effect after a couple weeks, showing maximum efficacy at one month. It also shows positive effects on redness, which is rare for a skin medication, Arbiser says. Few adverse effects were reported.

Arbiser says ACU-D1 could be an alternative to antibiotics, a common systemic treatment for rosacea. (Rosacea is partly an inflammatory response to microbes in the skin.) He is interested in studying ACU-D1’s efficacy for other inflammatory skin conditions such as eczema and psoriasis.

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Promiscuous protein droplets regulate immune gene activity

Biochemists at Emory are achieving insights into how an important regulator of the immune system switches its function, based on its orientation and local environment. New research demonstrates that the glucocorticoid receptor (or GR) forms droplets or “condensates” that change form, depending on its available partners.

The inside of a cell is like a crowded nightclub or party, with enzymes and other proteins searching out prospective partners. The GR is particularly well-connected and promiscuous, and has the potential to interact with many other proteins. It is a type of protein known as a transcription factor, which turns some genes on and others off, depending on how it is binding DNA.

These are fluorescent droplets of the glucocorticoid receptor (GR) in red, with a coregulator protein in green. When DNA is added, the co-regulator forms its own droplets on the surface of GR droplets. Image courtesy of Filipp Frank

“It is now thought that most transcription factors form or are recruited into condensates, and that condensation modulates their function,” says Filipp Frank, PhD, first author of the paper and a postdoctoral instructor in Eric Ortlund’s lab in the Department of Biochemistry. “What’s new is that we identified a DNA-dependent change in GR condensates, which has not been described for other transcription factors.”

The results are published in Proceedings of the National Academy of Sciences. Ortlund is a co-author of the paper, along with postdoctoral fellow Xu Liu, PhD.

Understanding how the GR works could help researchers find anti-inflammatory drugs with reduced side effects. The GR is the target for corticosteroid drugs such as dexamethasone, which is currently used to treat COVID-19 as well as allergies, asthma and autoimmune diseases.

Corticosteroids’ harmful side effects are thought to come from turning on genes involved in metabolism and bone growth, while their desired anti-inflammatory effects result from turning other inflammatory and immune system genes off. Researchers want to find alternatives that could separate those two functions.

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Neutrophils flood lungs in severe COVID-19

“First responder” cells called neutrophils are the dominant type of immune cells flooding the airways of people with severe COVID-19, according to a recent analysis of African-American patients in Emory hospitals.

The findings were posted on the preprint server Biorxiv prior to peer review.

Neutrophils are the most abundant immune cells in the blood, and usually the first to arrive at the site of a bacterial or viral infection. But in the lungs of severe COVID-19 patients, neutrophils camp out and release tissue-damaging enzymes, the new research shows. They also produce inflammatory messengers that induce more neutrophils to come to the lungs. 

Lung inflammation photo from NIEHS. Most of these dense small cells are neutrophils

This circulating cell type enters the lung and initiates a self-sustaining hyper-inflammation that leads to acute respiratory distress syndrome (ARDS), the leading cause of mortality in COVID-19, says lead author Eliver Ghosn assistant professor of medicine at Emory University School of Medicine.

“Our findings reveal novel therapeutic targets, and developing tactics to intervene could benefit severe patients in the ICU, particularly those that are most vulnerable,” Ghosn says. “We compared our lung data with matching blood samples for all the patients, and we were able to identify the subtype of neutrophils in the blood that is most likely to infiltrate the lungs of severe patients and cause ARDS.”

Somewhat counter-intuitively, Emory researchers had difficulty detecting SARS-CoV-2 infected cells in the upper airways of hospitalized patients. This result, consistent with findings by others, may explain why antiviral drugs such as remdesivir are ineffective once systemic inflammation has gained momentum; lung injury comes more from the influx of immune cells, such as neutrophils, rather than viral infection itself.

When Ghosn and his colleagues began examining immune cells in COVID-19, they found that almost all of the hospitalized patients they encountered were African-American. This highlights the racial disparities of the COVID-19 pandemic, especially in Georgia, and Ghosn’s team decided to “lean in” and focus on African-Americans. They collaborated closely with Eun-Hyung Lee’s lab at Emory to collect samples from hospitalized patients. 

“We believe these results can have broader implications and be applied to other demographics that suffer from similar lung pathology,” Ghosn says.

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Dissecting atherosclerosis at the single cell level: tasting each piece of a fruit salad

More than a decade ago, Hanjoong Jo and colleagues developed an elegant animal model allowing the dissection of atherosclerosis. It was the first to definitively show that disturbed patterns of blood flow determine where atherosclerotic plaques will later appear.

In atherosclerosis, arterial walls thicken and harden because of a gradual build-up of lipids, cholesterol and white blood cells, which occurs over the course of years in humans. The Jo lab’s model involves restricting blood flow in the carotid artery of mice, which are fed a high-fat diet and also have mutations in a gene (ApoE) involved in processing fat and cholesterol. The physical intervention causes atherosclerosis to appear within a couple weeks. Inflammation in endothelial cells, which line blood vessels, is visible within 48 hours.

The shear-sensitive gene LMO4 is turned on in the middle boxed region, but not the other two, because of disturbed flow in that area of the aorta

Now Jo’s lab has combined the model with recently developed techniques that permit scientists to see molecular changes in single cells. The results were published Tuesday in Cell Reports.

Jo’s lab is in the Wallace H. Coulter Department of Biomedical Engineering at Emory and Georgia Tech.

Previously, when they saw inflammation in blood vessels, researchers could not distinguish between intrinsic changes in endothelial cells and immune or other cells infiltrating into the blood vessel lining.

A video made by Harvard scientists who developed the single cell techniques describes the difference like this. Looking at the molecules in cells with standard techniques is like making a fruit smoothie – everything is blended together. But single cell techniques allow them to taste and evaluate each piece of fruit individually.

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Repurposing a rheumatoid arthritis drug for COVID-19

For COVID-19, many researchers around the world have tried to repurpose drugs for other indications, often unsuccessfully. New clinical trial results show that baricitinib, developed by Eli Lilly and approved for rheumatoid arthritis, can speed recovery and may reduce mortality in some groups of hospitalized COVID-19 patients.

How did this study, sponsored by the National Institute of Allergy and Infectious Diseases, come together? In part, through decade-long groundwork laid by investigators at Emory, and their collaborations with others.

The ACTT-2 results were recently published in New England Journal of Medicine. (More formal NIAID and Emory press releases are here and here.)

For several years, drug hunter and virologist Raymond Schinazi and his team had been investigating a class of medications called JAK inhibitors, as an option for tamping down chronic inflammation in HIV infection. Schinazi was one of the first at Emory to investigate the use of anti-inflammatory agents for herpesviruses and HIV in combination with antiviral drugs. He believed that these viruses “hit and run,” leaving behind inflammation, even if they later go into hiding and seem to disappear.

In Schinazi’s lab, Christina Gavegnano had shown that JAK inhibitors had both anti-inflammatory and antiviral properties in the context of HIV — a project she started as a graduate student in 2010. JAK refers to Janus kinases, which regulate inflammatory signals in immune cells.

 “Our team was working on this for 10 years for HIV,” Gavegnano says. “There was a huge amount of data that we garnered, showing how this drug class works on chronic inflammation and why.” 

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Baricitinib effectively reduces COVID-19 lung inflammation in NHP model

In the race to halt the COVID-19 pandemic, researchers at Yerkes National Primate Research Center of Emory University share two important findings from their latest peer-reviewed, published study in Cell.

Rhesus monkeys are a valid animal model for COVID-19 studies because the way they experience and respond to the virus has comparable similarities to the way the virus affects humans, the researchers say. And baricitinib, an anti-inflammatory medication that is FDA-approved for rheumatoid arthritis, is remarkably effective in reducing the lung inflammation COVID-19 causes when the medication is started early after infection.

The study results have immediate and important implications for treating patients with COVID-19. Baricitinib will be compared against the steroid dexamethasone in a NIAID-sponsored clinical trial called ACTT-4 (Adaptive COVID-19 Treatment Trial), which started in November.

Mirko Paiardini, PhD, a researcher in Yerkes’ Microbiology and Immunology division, and his team selected rhesus macaques as the animal model because they expected the monkeys would mimic the disease course in humans, including the virus traveling to the upper and lower airways, and causing high levels of inflammation in the lungs. The team randomized eight rhesus macaques into two groups – a control and a treatment group; the animals in the treatment group received baricitinib.

“Our results showed the medication reduced inflammation, decreased inflammatory cells in the lungs and, ultimately, limited the virus’ internal path of destruction,” Paiardini says. “Remarkably, the animals we treated with baricitinib rapidly suppressed the processes responsible for inducing lung inflammation, thus elevating baricitinib for consideration as a frontline treatment for COVID-19 and providing insights on the way the drug works and its effectiveness.”

The FDA recently granted baricitinib emergency use authorization in combination with remdesivir based on the results of the ACTT-2 findings. “Our study was under way concurrently and, now, solidifies the importance of baricitinib in treating COVID-19,” Paiardini adds.

Co-senior author Raymond Schinazi, PhD, DSc, inventor of the most commonly used HIV/AIDS drugs to prevent progression of the disease and death, says: “Our study shows the mechanisms of action are consistent across studies with monkeys and clinical trials with humans. This means the nonhuman primate model can provide enough therapeutic insights to properly test anti-inflammatory and other COVID-19 therapies for safety and effectiveness.”

Schinazi is the Frances Winship Walters Professor of Pediatrics at Emory University School of Medicine and is affiliated with Yerkes.

“Ray and his group have been investigating the potential of anti-inflammatory drugs, such as baricitinib, for years in the context of another infection, HIV, in which inflammation is a key cause of sickness and death,” Paiardini says. “Our laboratories have collaborated for years to test therapeutics in the nonhuman primate model of HIV infection, thus placing us in a unique position when COVID-19 hit the U.S. to focus our combined expertise and efforts to halt the virus. It took only a phone call between the two of us to switch gears, begin work to create a reliable and robust monkey model of COVID-19 at Yerkes and test the potential of drugs to block inflammation.”

Tim Hoang, first author and Emory doctoral student in the Immunology and Molecular Pathogenesis Program, says: “It was exciting to be at the forefront of the response to COVID-19 and to be part of this research team that involved collaboration from Yerkes and Emory infectious disease experts, geneticists, chemists, pathologists and veterinarians.”

Co-first author and Emory postdoctoral fellow Maria Pino, PhD, emphasizes: “We knew Yerkes was uniquely suited to conduct this study because of the research and veterinary expertise, specialized facilities and animal colony, and our team’s commitment to providing better treatment options for people who have COVID-19.”

The research team plans to conduct further studies to better understand the inflammation the virus causes and to develop more targeted approached to mitigate the damage COVID-19 leaves behind.

Steven Bosinger, PhD, co-senior author, and his research team conducted the genomic analyses that helped unravel the process by which baricitinib reduces inflammation. “One of the most exciting aspects of this project was the speed genomics brought to the collaborative research,” says Bosinger. “Eight months ago, we began using genomics to accelerate the drug screening process in order to identify treatable, molecular signatures of disease between humans and model organisms, such as the monkeys in this study, In addition to determining the effectiveness of baricitinib, this study highlights Emory researchers’ commitment to improving human health and, in this case, saving human lives.”

Bosinger is assistant professor, Department of Pathology & Laboratory Medicine, Emory School of Medicine (SOM) and Emory Vaccine Center (EVC); director, Yerkes Nonhuman Primate Genomics Core and a researcher in Yerkes’ Division of Microbiology and Immunology. 

Some of the others on the Emory research team include: Arun Boddapati (co-first author), Elise Viox, Thomas Vanderford, PhD, Rebecca Levit, MD, Rafick Sékaly, PhD, Susan Ribeiro, PhD, Guido Silvestri, MD, Anne Piantadosi, MD, PhD, Sanjeev Gumber, BVSc, MVSc, PhD, DACVP, Sherrie Jean, DVM, DACLAM, and Jenny Wood, DVM, DACLAM. Jacob Estes, PhD, at Oregon Health & Science University also collaborated.

Paiardini says, “So many colleagues had a key role in this study. First authors Tim and Maria as well as Yerkes veterinary and animal care personnel who worked non-stop for months on this project. This truly has been a collaborative effort at Emory University to help improve lives worldwide.”

This study was funded by the National Institutes of Health, Emory University’s COVID-19 Molecules and Pathogens to Populations and Pandemics Initiative Seed Grant, Yerkes’ base grant, which included support for the center’s Coronavirus Pilot Research Project grants, and Fast Grants.

Grant amounts (direct + indirect) are:

NIH R37AI141258, $836,452/yr (2018-23)

NIH R01AI116379, $783,714/yr (2015-20 + 2021 NCE)

NIH P51 OD011132, $10,540,602/yr (2016-20)

U24 AI120134 $681,214/yr (2020-2025)

S10OD026799 $985,030/yr (2019-2020)

Emory University COVID-19 Molecules and Pathogens to Populations and Pandemics Initiative Seed Grant, $150,000/1 yr

Fast Grants #2144, $100,000/1 yr

Note: Only a portion of the NIH grant funding was applied to the study reported in this news release. 

Posted on by Quinn Eastman in Immunology Leave a comment

Peeling away pancreatic cancers’ defenses

At Winship Cancer Institute, pancreatic cancer researcher Greg Lesinski and colleagues have a new paper in Molecular Cancer Therapeutics. It’s about a combination immunotherapy approach that gets through pancreatic cancers’ extra defenses, and it represents the preclinical counterpart to a clinical trial that is underway and almost finished at Winship, under the direction of GI oncologist Bassel El-Rayes.

Immunotherapies have transformed how other forms of cancer are treated, but for pancreatic cancers, an obstacle is getting through the dense layers of cellular shielding that the cancers build around themselves. Pancreatic cancers create “nests” of fibrotic stellate cells that pump out inflammatory cytokines such as IL-6.

Pancreatic cancer is anticipated to become the second deadliest cancer in the United States by 2030, surpassing breast and colon cancer. 

“Inflammation and a good immune response don’t always go hand in hand,” El-Rayes told us, for a 2018 Winship magazine article. “High IL-6 causes immune exhaustion, and keeps the good cells out of the tumor.”

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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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SARS-CoV-2 culture system using human airway cells

Journalist Roxanne Khamsi had an item in Wired highlighting how virologists studying SARS-CoV-2 and its relatives have relied on Vero cells, monkey kidney cells with deficient antiviral responses.

Vero cells are easy to culture and infect with viruses, so they are a standard laboratory workhorse. Unfortunately, they may have given people the wrong idea about the controversial drug hydroxychloroquine, Khamsi writes.

In contrast, Emory virologist Mehul Suthar’s team recently published a Journal of Virology paper on culturing SARS-CoV-2 in primary human airway epithelial cells, which are closer to the cells that the coronavirus actually infects “out on the street.”

Effect of interferon-beta on SARS-CoV-2 in primary human epithelial airway cells. Green = SARS-CoV-2, Red = F-actin, Blue = Hoechst (DNA). Courtesy of Abigail Vanderheiden

The Emory researchers found that airway cells are permissive to SARS-CoV-2 infection, but mount a weak antiviral response lacking certain interferons (type I and type III). Interferons are cytokines, part of the immune system’s response to viral infection. They were originally named for their ability to interfere with viral replication, but they also rouse immune cells and bolster cellular defenses.

In SARS-CoV-2 infection, the “misdirected” innate immune response is dominated instead by inflammatory and fibrosis-promoting cytokines, something others have observed as well.

“Early administration of type I or III IFN could potentially decrease virus replication and disease,” the authors conclude. We note that an NIH-supported clinical trial testing a type I interferon (along with remdesivir) for COVID-19 just started.

The first author of the paper is IMP graduate student Abigail Vanderheiden. As with a lot of recent SARS-CoV-2 work, this project included contributions from several labs at Emory: Arash Grakoui’s, Steve Bosinger’s, Larry Anderson’s, and Anice Lowen’s, along with help from University of Texas Medical Branch at Galveston.

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Anti-inflammatory approach suppresses cancer metastasis in animal models

An anti-inflammatory drug called ketorolac, given before surgery, can promote long-term survival in animal models of cancer metastasis, a team of scientists has found. The research suggests that flanking chemotherapy with ketorolac or similar drugs — an approach that is distinct from previous anti-inflammatory cancer prevention efforts — can unleash anti-tumor immunity.

The findings, published in Journal of Clinical Investigation, also provide a mechanistic explanation for the anti-metastatic effects of ketorolac, previously observed in human breast cancer surgery.

Medical writer Ralph Moss has a great summary of this background. A commentary accompanying the JCI paper concludes: ” If this can be translated from mouse models into the clinic, then it could revolutionize treatments.”

Vikas P. Sukhatme, MD, ScD, dean of Emory University School of Medicine, is senior author of the JCI paper. He was previously at Beth Israel Deaconess Medical Center and Harvard Medical School, with lead authors Dipak Panigrahy, MD and Allison Gartung, PhD.

“Collectively, our findings suggest a potential paradigm shift in our approach to resectable cancers,” says Sukhatme. “Clinical trials are now urgently needed to validate these animal studies.”

Most cancer-related deaths come from metastases, the spread of cancer cells from a primary tumor to surrounding tissues or distant organs. The cells that seed metastases are often in microscopic clusters – a surgeon can’t see them. Chemotherapy, typically given after or prior to surgery is aimed at eradicating these cancer cells in the hopes of preventing cancer recurrence.  However, chemotherapy can sometimes stir up inflammation, promoting metastasis.

“Cancer therapy is a double-edged sword,” says Panigrahy. “Surgery and chemotherapy can induce an inflammatory or immunosuppressive injury response that promotes dormant metastatic cells to start proliferating, leading to tumor recurrence.”

Ketorolac is an inexpensive NSAID (nonsteroidal anti-inflammatory drug). Because of concern over side effects, it is only approved by the FDA for short-term pain management “at the opioid level.” It differs from other NSAIDs in that it preferentially inhibits the enzyme COX-1, more than COX-2. Other studies of prevention of cancer recurrence have focused on COX-2 inhibitors. Read more

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