Quinn Eastman

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.”

Read more

Posted on by Quinn Eastman in Cancer Leave a comment

Immune cell activation in severe COVID-19 resembles lupus

In severe cases of COVID-19, Emory researchers have been observing an exuberant activation of B cells, resembling acute flares in systemic lupus erythematosus (SLE), an autoimmune disease.

The findings point towards tests that could separate some COVID-19 patients who need immune-calming therapies from others who may not. It also may begin to explain why some people infected with SARS-CoV-2 produce abundant antibodies against the virus, yet experience poor outcomes.

The results were published online on Oct. 7 in Nature Immunology.

The Emory team’s results converge with recent findings by other investigators, who found that high inflammation in COVID-19 may disrupt the formation of germinal centers, structures in lymph nodes where antibody-producing cells are trained. The Emory group observed that B cell activation is moving ahead along an “extrafollicular” pathway outside germinal centers – looking similar to what they had observed in SLE.

Update: check out first author Matthew Woodruff’s commentary in The Conversation: “The autoimmune-like inflammatory responses my team discovered could simply reflect a ‘normal’ response to a viral infection already out of hand. However, even if this kind of response is ‘normal,’ it doesn’t mean that it’s not dangerous.”

B cells represent a library of blueprints for antibodies, which the immune system can tap to fight infection. In severe COVID-19, the immune system is, in effect, pulling library books off the shelves and throwing them into a disorganized heap.

Before the COVID-19 pandemic, co-senior author Ignacio (Iñaki) Sanz and his lab were focused on studying SLE and how the disease perturbs the development of B cells.

“We came in pretty unbiased,” Sanz says. “It wasn’t until the third or fourth ICU patient whose cells we analyzed, that we realized that we were seeing patterns highly reminiscent of acute flares in SLE.”

In people with SLE, B cells are abnormally activated and avoid the checks and balances that usually constrain them. That often leads to production of “autoantibodies” that react against cells in the body, causing symptoms such as fatigue, joint pain, skin rashes and kidney problems. Flares are times when the symptoms are worse.

Read more

Posted on by Quinn Eastman in Immunology Leave a comment

Muscle cell boundaries: some assembly required

With cold weather approaching, many are digging out old jackets to find that the zippers don’t function as well as they used to. This is a good way to understand disruptions of muscle cell attachment studied by Emory cell biologist Guy Benian’s lab. 

Benian and colleagues have a paper on muscle cell biology in Nature Communications this week. In the worm C. elegans, they show how mutations cause junctions between muscle cells, which normally look like well-aligned zippers under the microscope, to either not form, or weaken and unravel. As a result, the mutant worms’ snake-like locomotion is impaired.

Zipper-like muscle cell boundaries are altered in pix-1 mutants

“This is yet another example in which research using the model genetic organism C. elegans has led to a new insight applicable to all animals, including humans,” Benian says. “Research on this organism has led to crucial advances in our understanding about development, cell death, aging and longevity, RNAi, microRNAs, epigenetics — and muscle.”

Read more

Posted on by Quinn Eastman in Uncategorized Leave a comment

The sweet side of Alzheimer’s proteomics

The Alzheimer’s field has been in a “back to the basics” mode lately. Much research has focused on beta-amyloid, the toxic protein fragment that accumulates in plaques in the brain. Yet drugs that target beta-amyloid have mostly been disappointing in clinical trials.

To broaden scope and gain new insights into the biology of Alzheimer’s, Emory investigators have been making large-scale efforts to catalog alterations of brain proteins. One recent example: Nick Seyfried and Erik Johnson’s enormous collection of proteomics data, published this spring in Nature Medicine. Another can be seen in the systematic mapping of N-glycosylation, just published in Science Advances by pharmacologist Lian Li and colleagues.

“It is very exciting to see, for the first time, the landscape of protein N-glycosylation changes in Alzheimer’s brain,” Li says. “Our results suggest that the N-glycosylation changes may contribute to brain malfunction in Alzheimer’s patients.  We believe that targeting N-glycosylation may provide a new opportunity to help combat this devastating dementia.”

Read more

Posted on by Quinn Eastman in Neuro Leave a comment

Fragile X: $8 million NIH grant supports next-generation neuroscience

Supported by a $8 million, five-year grant, an Emory-led team of scientists plans to investigate new therapeutic approaches to fragile X syndrome, the most common inherited intellectual disability and a major single-gene cause of autism.

Fragile X research represents a doorway to a better understanding of autism, and learning and memory. The field has made strides in recent years. Researchers have a good understanding of the functions of the FMR1 gene, which is silenced in fragile X syndrome.

Still, clinical trials based on that understanding have been unsuccessful, highlighting limitations of current mouse models. Researchers say the answer is to use “organoid” cultures that mimic the developing human brain.

The new grant continues support for the Emory Fragile X Center, first funded by the National Institutes of Health in 1997. The Center’s research program includes scientists from Emory as well as Stanford, New York University, Penn and the University of Southern California. The Emory Center will be one of three funded by the National Institutes of Health; the others are at Baylor College of Medicine and Cincinnati Children’s Hospital Medical Center.

The co-directors for the Emory Fragile X Center are Peng Jin, PhD, chair of human genetics, and Stephen Warren, PhD, William Patterson Timmie professor and chair emeritus of human genetics. In the 1980s and 1990s, Warren led an international team that discovered the FMR1 gene and the mechanism of trinucleotide repeat expansion that silences the gene. This explained fragile X syndrome’s distinctive inheritance pattern, first identified by Emory geneticist Stephanie Sherman, PhD.

“Fragile X research is a consistent strength for Emory, stretching across several departments, based on groundbreaking work from Steve and Stephanie,” Jin says. “Now we have an opportunity to apply the knowledge we and our colleagues have gained to test the next generation of treatments.”

Fragile X researchers from three Emory departments, following COVID-19 spacing guidelines in the laboratory. From left to right: Peng Jin, Gary Bassell, Zhexing Wen and Nisha Raj.

Looking ahead, a key element of the Center’s research will involve studying the human brain in “disease in a dish” models, says Gary Bassell, PhD, chair of cell biology. Nisha Raj, PhD, a postdoctoral fellow in Bassell’s lab, has been studying how FMR1 regulates localized protein synthesis at the brain’s synapses.

“What we’re learning is that there may be different RNA targets in human and mouse cells,” he says. “There’s a clear need to regroup and incorporate human cells into the research.”

Microscope images of fragile X human brain organoids, courtesy of Zhexing Wen. Green represents cytoplasmic Nestin while red represents nuclear Sox2; both are markers for neural progenitor cells.
Microscope image of fragile X human brain organoids, courtesy of Zhexing Wen. Green represents cytoplasmic Nestin while red represents nuclear Sox2; both are markers for neural progenitor cells. 

Center investigator Zhexing Wen, PhD, has developed techniques for culturing brain organoids (image above), which reproduce features of human brain development in miniature. Wen, assistant professor of psychiatry and behavioral sciences, cell biology and neurology at Emory, has used organoids to model other disorders, such as schizophrenia and Alzheimer’s disease. 

The organoids are formed from human brain cells, coming from induced pluripotent stem cells, which are in turn derived from patient-donated tissues. Emory’s Laboratory of Translational Cell Biology, directed by Bassell, has developed several lines of induced pluripotent stem cells from fragile X syndrome patients.

“All of the investigators are sharing these valuable resources and collaborating on multiple projects,” Bassell says.

Principal investigators in the Emory Fragile X Center are Jin, Warren, Bassell, and Wen, along with Eric Klann, PhD at New York University, Lu Chen, PhD, and 2013 Nobel Prize winner Thomas Südhof, MD. Chen and Südhof are neuroscientists at Stanford.

Co-investigators include biostatistician Hao Wu, PhD and geneticist Emily Allen, PhD at Emory, neuroscientist Guo-li Ming, MD, PhD, at University of Pennsylvania, and biomedical engineer Dong Song, PhD, at University of Southern California.
 
Allen, Warren and Jin are part of an additional grant to Baylor, Emory and University of Michigan investigators, who are focusing on FXTAS (fragile X-associated tremor-ataxia syndrome) and FXPOI (fragile X-associated primary ovarian insufficiency). These are conditions that affect people with fragile X premutations.

Fragile X syndrome is caused by a genetic duplication on the X chromosome, a “triplet repeat” in which a portion of the gene (CGG) gets repeated again and again. Fragile X syndrome affects about one child in 5,000, and is more common and more severe in boys. It often causes mild to moderate intellectual disabilities as well as behavioral and learning challenges. About a third of children affected have characteristics of autism, such as problems with eye contact, social anxiety, and delayed speech. 
 
The award for the Emory Fragile X Center is administered by the Eunice Kennedy Shriver National Institute of Child Health and Human Development, with funding from the National Institute of Mental Health and the National Institute of Neurological Disorders and Stroke.

Posted on by Quinn Eastman in Neuro Leave a comment

Detecting heart failure via wearable devices

Cardiology researchers have been eagerly taking up consumer electronic devices that include pulse oximeters. Being able to conveniently measure the level of oxygen in someone’s blood is a useful tool, whether one is interested in sleep apnea or COVID-19.

The news that the new Apple Watch includes a pulse oximeter prompted Lab Land to check in with Amit Shah, an Emory cardiologist who has been experimenting with similar devices to discriminate patients with heart failure from those with other conditions.

Shah, together with Shamim Nemati, now at UCSD, and bioinformatics chair Gari Clifford recently published a pilot study on detecting heart failure using the Samsung Simband. The Simband was a prototype device that didn’t make it to the consumer market, but it carried sensors for optical detection of blood volume changes (photoplethysmography), like on the Apple Watch. 

Heart failure causes symptoms such as shortness of breath and leg swelling, but other conditions such as anemia or lung diseases can appear similarly. The idea was to help discriminate people who might need an examination by echocardiogram (cardiac ultrasound).

Read more

Posted on by Quinn Eastman in Uncategorized Leave a comment

Elevated troponin after exercise refines cardiac risk prediction

High levels of troponin, a sign of acute stress to the heart, in the blood reveal whether someone recently experienced a heart attack. Advances in testing have made it possible to detect much lower levels of troponin — but still elevated above zero. For example, elevated troponin can be detected after strenuous exercise, even in healthy young athletes.

With that exercise-induced response in mind, Emory Clinical Cardiovascular Research Institute investigators have been studying whether high-sensitivity troponin measurements might be used to replace cardiac stress tests. These procedures are expensive and sometimes involve nuclear imaging, which exposes patients to radiation.

A new paper in American Journal of Cardiology shows how elevated high-sensitivity troponin levels in response to exercise on a treadmill can predict future outcomes in patients with coronary artery disease — better than stress tests with imaging.

Read more

Posted on by Quinn Eastman in Heart Leave a comment

Several ways to survey for SARS-CoV-2 exposure

How many people out there have been exposed to SARS-CoV-2? It’s a tricky question, once you think about all the people who have experienced COVID-19 symptoms over the last several months, but didn’t go to the hospital. And there’s a murkier penumbra of people who may have fended off the virus with a minor immune skirmish.

A recent Emerging Infectious Diseases paper from Emory investigators includes antibody tests on a group of more than 100 adults in the Atlanta area who experienced mild flu-like symptoms this spring, but couldn’t get tested for SARS-CoV-2 itself.

A sizable fraction (22 to 48 percent, depending on when they provided blood samples) had elevated levels of IgM against the coronavirus. IgM is the “rookie” antibody produced when the immune system is first encountering something, as opposed to the more seasoned IgG, which appears later in an immune response and tended to rise only in people who were hospitalized. The Emory authors came to a conclusion that others are also reaching:

“Examining IgM and IgG against multiple SARS-CoV-2–related antigens may thus better inform natural history and vaccine studies than any one antibody.”

To answer these kinds of questions more comprehensively, investigators will need to go broader. For example, this week the American Red Cross published data on what proportion of its blood donors have antibodies against SARS-CoV-2. About 3 percent of first-time donors did, using their criteria.

For big answers, we can look to studies such as Emory’s COVID-Vu, a nationwide population-based study using antibody and virus tests taken at home. Rollins School of Public Health researchers received a $6.6 million grant to launch the study this summer. This type of study is designed to cover everyone, whether they were sick or not.

Read more

Posted on by Quinn Eastman in Uncategorized Leave a comment

For genetically altered mice/rats, freeze and recharge

With a pandemic threatening the health and safety of Emory researchers in March 2020, university leadership made the difficult decision to ramp down some types of research. For investigators that use laboratory mice or rats in their research, this posed a significant challenge.

How could investigators maintain valuable, often unique, lines of genetically engineered animals for future research? The Mouse Transgenic and Gene Targeting Core (TMF) had a solution: cryopreservation. Animals’ sperm — and occasionally, embryos – can be carefully preserved in cold-resistant straws and stored in liquid nitrogen.

“Cryopreservation is a reliable and efficient method for archiving and distributing genetically engineered mouse lines,” says Karolina Piotrowska-Nitsche, PhD, director of the Core.

The TMF is located on the ground floor of the Emory Health Sciences Research Building and provides a suite of services related to transgenics and gene editing, working with tools such as CRISPR/Cas9 to make subtle or complex changes in the DNA of living animals.

Read more

Posted on by Quinn Eastman in Uncategorized Leave a comment

Georgia survey on COVID-19 testing/vaccination shows group differences

Public health experts stress that adequate representation of Black and Latinx people in COVID-19 vaccine studies is a priority. Given how COVID-19 is impacting vulnerable communities, acceptance of a future vaccine – whenever it may become available – is important. A recent article in the Atlanta Journal Constitution highlights how this issue is playing out in Georgia, given the legacy of lack of trust in biomedical research.

“The issue of minority participation in clinical trials is not just in vaccines, it really is in every clinical trial and the point is that the population that is most impacted and most affected needs to be represented in trials,” Emory’s Carlos del Rio said at a media briefing last week.

In a Sunday Op-Ed in the AJC, emergency physician Monique Smith called attention to the disparities in COVID-19 testing and follow-up. In the communities she serves, it is not just a challenge to get a test but to also understand what the results mean, or what to do while waiting for the results, she says.

Lab Land can add some data to that – a survey conducted by neurologist William Hu and colleagues in early August on attitudes toward COVID-19 testing and vaccination among Georgia residents. Non-Hispanic white respondents were more likely than Black/African-American respondents to recommend their loved ones to participate in a COVID-19 clinical trial or be vaccinated after FDA approval.

Green = Black/African-Americans, Clear = non-Hispanic white

From August survey data

Read more

Posted on by Quinn Eastman in Uncategorized Leave a comment
1 2 3 4 5 6 7 8 9 10 ... 66 67   Next »