Quinn Eastman

Mouse version of 3q29 deletion: insights into schizophrenia/ASD pathways

Scientists at Emory University School of Medicine have created a mouse model of human 3q29 deletion syndrome, which is expected to provide insights into the genetic underpinnings of both schizophrenia and autism spectrum disorder.

In 3q29 deletion syndrome, a stretch of DNA containing several genes is missing from one of a child’s chromosomes. The deletion usually occurs spontaneously rather than being inherited. Affected individuals have a higher risk of developing intellectual disability, schizophrenia, and autism spectrum disorder. 3q29 deletion is one of the strongest genetic risk factors for schizophrenia, and the Emory researchers see investigating it as a way of unraveling schizophrenia’s biological and genetic complexity.

The results were published in Molecular Psychiatry.

“We see these mice as useful tools for understanding the parts of the brain whose development is perturbed by 3q29 deletion, and how it affects males and females differently,” says Jennifer Mulle, PhD, assistant professor of human genetics. “They are also a starting point for dissecting individual genes within the 3q29 deletion.”

Working with clinicians and psychologists at Marcus Autism Center, Mulle is leading an ongoing study of 3q29 deletion’s effects in humans, and observations from the mice are expected to inform these efforts. (More about Mulle here.) Read more

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B cells off the rails early in lupus

New research on the autoimmune disease systemic lupus erythematosus (SLE) provides hints to the origins of the puzzling disorder. The results are published in Nature Immunology.

In people with SLE, their B cells – part of the immune system – are abnormally activated. That makes them produce antibodies that react against their own tissues, causing a variety of symptoms, such as fatigue, joint pain, skin rashes and kidney problems.

Scientists at Emory University School of Medicine could discern that in people with SLE, signals driving expansion and activation are present at an earlier stage of B cell differentiation than previously appreciated. They identified patterns of gene activity that could be used as biomarkers for disease development.

Activation can be observed at an early stage of B cell differentiation: resting naive cells (pink ellipse). Adapted from Jenks et al Immunity (2018).

“Our data indicate a disease signature across all cell subsets, and importantly on mature resting B cells, suggesting that such cells may have been exposed to disease-inducing signals,” the authors write.

The paper reflects a collaboration between the laboratories of Jeremy Boss, PhD, chairman of microbiology and immunology, and Ignacio (Iñaki) Sanz, MD, head of the division of rheumatology in the Department of Medicine. Sanz, recipient of the 2019 Lupus Insight Prize from the Lupus Research Alliance, is director of the Lowance Center for Human Immunology and a Georgia Research Alliance Eminent Scholar. The first author is Christopher Scharer, PhD, assistant professor of microbiology and immunology.

The researchers studied blood samples from 9 African American women with SLE and 12 healthy controls. They first sorted the B cells into subsets, and then looked at the DNA in the women’s B cells, analyzing the patterns of gene activity. Sanz’s team had previously observed that people with SLE have an expansion of “activated naïve” and DN2 B cells, especially during flares, periods when their symptoms are worse. Read more

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Head to head narcolepsy/hypersomnia study

At the sleep research meeting in San Antonio this year, there were signs of an impending pharmaceutical arms race in the realm of narcolepsy.

The big fish in a small pond, Jazz Pharmaceuticals, was preparing to market its recently FDA-approved medication: Sunosi/solriamfetol. Startup Harmony Biosciences was close behind with pitolisant, already approved in Europe. On the horizon are experimental drugs designed to more precisely target the neuropeptide deficiency in people with classic narcolepsy type 1 (for narcolepsy with cataplexy: hypocretin/orexin agonists).

Amidst this commercial maneuvering, a new clinical trial is underway at Emory Sleep Center. The study compares modafinil versus amphetamines for narcolepsy type 2 (NT2) and idiopathic hypersomnia (IH).

These are not new drugs; they are old standards, when used to treat other sleep disorders. What’s remarkable here is that they are being tested “head-to-head.” In addition, the study explicitly tracks outcomes that people with NT2 and IH often talk about: sleep inertia, or difficulty waking up and getting out of bed in the morning, and brain fog, which is difficulty thinking/concentrating/paying attention. The main outcome measure is the Epworth Sleepiness Scale, which asks how likely someone is to fall asleep during daytime situations such as reading or while stopped in traffic. Read more

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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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I3 Venture awards info

Emory is full of fledgling biomedical proto-companies. Some of them are actual corporations with employees, while others are ideas that need a push to get them to that point. Along with the companies highlighted by the Emory Biotech Consulting Club, Dean Sukhatme’s recent announcement of five I3 Venture research awards gives more examples of early stage research projects with commercial potential.

This is the third round of the I3 awards; the first two were Wow! (basic discovery) and Synergy II/Nexus (promoting interdisciplinary collaboration). For the five Venture awards, the Dean’s office is providing a total of $100,000. The companies will then use the momentum to seek larger amounts of funding from various sources. Lab Land is still collecting information on the projects:

 

Faculty Name Technology Relevant links
Ray Dingledine + Thota Ganesh Pyrefin EP2 receptor antagonists vs epilepsy, pain, inflammation New class of potential drugs inhibits inflammation in brain
Mark Goodman, W. Robert Taylor Microbial Medical PET imaging agent for detection of bacterial infections Spoonful of sugar helps infection detection
Carlos Moreno + Christian Larsen ResonanceDx Miniaturized rapid creatinine test for point of care use  
Edmund Waller + Taofeek Owonikoko Cambium Oncology Enhancing responsiveness of pancreatic cancer to immunotherapy The Company’s lead compound was effective in animal studies for pancreatic cancer, melanoma, leukemia and lymphoma.
Chunhui Xu TK High-throughput screening for antiarrhythmic drugs using cardiomyocytes Fetal alcohol toxicity – in a dish // Cardiac ‘disease in a dish’ models advance arrhythmia research
Posted on by Quinn Eastman in Cancer, Immunology, Neuro Leave a comment

Take heart, Goldilocks — and get more sleep

Sleeping too little or too much increases the risk of cardiovascular events and death in those with coronary artery disease, according to a new paper from Emory Clinical Cardiovascular Research Institute.

Others have observed a similar U-shaped risk curve in the general population, with respect to sleep duration. The new study, published in American Journal of Cardiology, extends the finding to people who were being evaluated for coronary artery disease.

Arshed Quyyumi, MD and colleagues analyzed data from a registry of 2846 patients undergoing cardiac catheterization at Emory. The “sweet spot” appeared to be those who report sleeping between 6.5 and 7.5 hours per night.

39 percent of patients with coronary artery disease reported that they slept fewer than 6.5 hours per night, and 35 percent slept longer than 7.5 hours. For the next few years, both groups had higher risks of all-cause mortality: elevated risk of 45 percent and 41 percent, respectively. Patients were followed for an average of 2.8 years.

The extreme ends of sleep duration both had even higher risk: people who reported less than 4.5 hours per day had almost double mortality risk (96 percent), and those more than 8.5 hours had 84 percent higher mortality risk.

Patients with short sleep durations also had higher cardiovascular mortality (48 percent), but adjusting for cardiovascular risk factors attenuated the association between long sleep duration and CV risk.

A detailed assessment of someone’s sleep can require PSG (polysomnography). In this study,  researchers were able to get information by simply asking about sleep duration.

The participants in the Emory study were simply asked: “How many hours of sleep do you usually get each night (or when you usually sleep)?” This question may not always be answered accurately, since time in bed isn’t necessarily time asleep. Still, the broad strokes show that the sleep-CV health relationship is robust.

“What is most stunning to me are that these data were collected from cardiac patients about to undergo an invasive procedure, who still reported an aspect of their sleep that was meaningful and predictive of future survival,” says Donald Bliwise, PhD, a specialist in sleep and aging research who is a co-author on the Emory study. “Often, epidemiologic studies collect data far away from a clinic setting, where anxiety is less and estimations may be sharper. We have here in this clinical study beautiful evidence that estimates made ‘from the gurney’ may be just as meaningful as those collected in the field.”

Quyyumi says if patients with heart disease are sleeping poorly, it’s important to recognize that they are at higher risk and counsel them regarding getting more sleep, as well as factors that can disrupt sleep, such as caffeine, alcohol and looking at screens late in the day.

More specific treatments may depend what is interfering with high-quality sleep in a given patient. Several conditions can lead to difficulty sleeping, such as sleep apnea, restless leg syndrome, as well as depression, all of which have been linked with heart disease. Physiologically, several mechanisms are probably exerting their effects, such as weakening circadian rhythms and sleep fragmentation with aging, and obesity/metabolic syndrome driving inflammation. Read more

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Repurposing a transplant drug for bone growth

The transplant immunosuppressant drug FK506, also known as tacrolimus or Prograf, can stimulate bone formation in both cell culture and animal models. This info comes from orthopedics researcher Nick Willett, PhD and colleagues, published in International Journal of Molecular Sciences (open access).

Nick Willett, PhD

The results suggest that FK506 might be repurposed as a “stand-alone” replacement for recombinant BMP-2 (bone morphogenic protein 2). That product has been a huge commercial success for Medtronic, in the context of spinal fusion surgeries, although controversial because of cost and side effects.

BMP-2 is more potent gram for gram, but FK506 still may offer some opportunities in local delivery. From Sangadala et al (2019)

One of Willett’s co-authors is orthopedics chair Scott Boden, MD, whose lab previously developed a system to search for drugs that could enhance BMP-2. Previously, other researchers had observed that FK506 can enhance the action of BMP-2 – this makes sense because FK506’s target protein is a regulator of the BMP pathway. Willett’s team used FK506 on its own, delivered in a collagen sponge.

“That is the big finding here, that it has the potential to be used on its own without any BMP-2,” he says.

The sponge is a possible mechanism for getting the drug to tissues without having too many systemic effects. Willett’s lab is now working on refining delivery, dosing and toxicity, he says.

Willett, based at the Atlanta VA Medical Center, is in the Department of Orthopedics and the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory. He and Sree Sangadala, PhD (first author of the IJMS paper) currently have a grant from National Center for Advancing Translational Sciences on this project.

 

 

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Beyond the amyloid hypothesis: proteins that indicate cognitive stability

If you’re wondering where Alzheimer’s research might be headed after the latest large-scale failure of a clinical trial based on the “amyloid hypothesis,” check this out.

Plaques. Tangles. Clumps. These are all pathological signs of neurodegenerative diseases that scientists can see under the microscope. But they don’t explain most of the broader trends of cognitive resilience or decline in aging individuals. What’s missing?

A recent proteomics analysis in Nature Communications from Emory researchers identifies key proteins connected with cognitive trajectory – meaning the rate at which someone starts to decline and develop mild cognitive impairment or dementia.

This paper fits in with the multi-year push for “unbiased” Alzheimer’s/aging research at Emory. The lead and senior authors are Aliza and Thomas Wingo, with proteomics from biochemist Nick Seyfried and company.

The proteins the Emory team spotlights are not the usual suspects that scientists have been grinding on for years in the Alzheimer’s field, such as beta-amyloid and tau. They’re proteins connected with cellular energy factories (mitochondria) or with synapses, the connections between brain cells.

“Our most notable finding is that proteins involving mitochondrial activities or synaptic functions had increased abundance among individuals with cognitive stability regardless of the burden of β-amyloid plaques or neurofibrillary tangles,” the authors write. “Taken together, our findings and others highlight that mitochondrial activities would be a fruitful research target for early prevention of cognitive decline and enhancement of cognitive stability.” Read more

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Mother’s milk is OK, even for the in-between babies

“Stop feeding him milk right away – just to be safe” was not what a new mother wanted to hear. The call came several days after Tamara Caspary gave birth to fraternal twins, a boy and a girl. She and husband David Katz were in the period of wonder and panic, both recovering and figuring out how to care for them.

“A nurse called to ask how my son was doing,” says Caspary, a developmental biologist in Emory’s Department of Human Genetics. “She started asking about vomiting and other specific symptoms.”

Her son had tested positive by newborn screening for a rare disorder called galactosemia. Galactosemia is an inherited disease that results from inability to metabolize galactose, a component of human milk and cow-milk-based formula. If a baby with “classic” galactosemia continues to drink milk, the baby may quickly develop symptoms such as jaundice, vomiting and diarrhea, progressing to liver disease and other serious complications that can lead to infant death. If a newborn has classic galactosemia, it is critical for the baby to stop drinking milk and switch to a low-galactose formula, such as soy-based formula, as soon as possible.

Caspary and Katz, a cell biologist, learned several days later that their son did not have classic galactosemia but instead had inherited Duarte galactosemia, a milder, more common form of the metabolic disorder, affecting more than 1 in 5,000 children in the United States. But there was still a looming question.

“We needed to figure out what to feed the baby!” Katz exclaimed, recalling their confusion years later.

The looming question was: what to feed the baby?

Their pediatrician didn’t know what to recommend. Galactosemia, in whatever form, is rare enough in the US that most pediatricians don’t develop experience with it. There was no uniform standard of care, and state-level guidelines for children with Duarte galactosemia varied widely, from no dietary restrictions to banning all milk products for the first year. Some of the limited research available at the time suggested that affected children might experience developmental problems as they grew up. Read more

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Focus on mitochondria in schizophrenia research

Despite advances in genomics in recent years, schizophrenia remains one of the most complex challenges of both genetics and neuroscience. The chromosomal abnormality 22q11 deletion syndrome, also known as DiGeorge syndrome, offers a way in, since it is one of the strongest genetic risk factors for schizophrenia.

Out of dozens of genes within the 22q11 deletion, several encode proteins found in mitochondria. A team of Emory scientists, led by cell biologist Victor Faundez, recently analyzed the network of proteins found in human cells, both from individuals affected by 22q11 deletion syndrome and their healthy relatives.

The results are published in Journal of Neuroscience. Note: this is a sprawling paper, involving both proteomics (courtesy of Nick Seyfried, whose Emory epithet is “wizard”) and mutant Drosophila fruit flies. There are four co-first authors: Avanti Gokhale, Cortnie Hartwig, Amanda Freeman and Julia Bassell.

Victor Faundez, PhD

Mitochondrial proteins are important for keeping cells fueled up and in metabolic balance, but how does altering them affect the brain in a way that leads to schizophrenia? That’s the overall question: how do changes in the miniature power plants within the cell affect synapses, the junctions between cells?

The scientists were focusing on one particular mitochondrial protein, SLC25A1, whose corresponding gene is in the 22q11 deletion. Faundez says that SCL25A1 has been largely ignored by other scientists studying 22q11.

“We think SLC25A1 exerts a powerful influence on the neurodevelopmental phenotypes in 22q11,” he says. “Our main focus forward is going to be the function that mitochondria play in synapse biology.” Read more

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