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Presidnet's Award for Innovation in Research

President’s Award highlights innovative work by early-career researchers

Presidnet's Award for Innovation in Research

As part of Research and Education Week 2018, two Presidential awardees were recognized for their research contributions, Catherine “Katie” Forster, M.D., M.S., and Nathan Anthony Smith, Ph.D.

Catherine “Katie” Forster, M.D., M.S., and Nathan Anthony Smith, Ph.D., received the President’s Award for Innovation in Research honoring their respective research efforts to explore an understudied part of the microbiome and to shed light on an underappreciated player in nerve cell communication.

Drs. Forster and Smith received their awards April 19, 2018, the penultimate day of Research and Education Week 2018, an annual celebration of the excellence in research, education, innovation and scholarship that takes place at Children’s National Health System. This year marks the fifth time the President’s Award honor has been bestowed to Children’s faculty.

Dr. Forster’s work focuses on preventing pediatric urinary tract infections (UTIs). Frequently, children diagnosed with illnesses like spina bifida have difficulty urinating on their own, and they often develop UTIs. These repeated infections are frequently treated with antibiotics which, in turn, can lead to the child developing antibiotic-resistant organisms.

“The majority of the time if you culture these children, you’ll grow something. In a healthy child, that culture would indicate a UTI,” Dr. Forster says. “Children with neurogenic bladder, however, may test positive for bacteria that simply look suspect but are not causing infection. Ultimately, we’re looking for better ways to diagnose UTI at the point of care to better personalize antibiotic treatment and limit prescriptions for children who do not truly need them.”

Powered by new sequencing techniques, a research group that includes Dr. Forster discovered that the human bladder hosts a significant microbiome, a diverse bacterial community unique to the bladder. Dr. Forster’s research will continue to characterize that microbiome to determine how that bacterial community evolves over time and whether those changes are predictable enough to intervene and prevent UTIs.

“Which genes are upregulated in Escherichia coli and the epithelium, and which genes are upregulated by both in response to each other? That can help us understand whether genes being upregulated are pathogenic,” she adds. “It’s a novel and exciting research area with significant public health implications.”

Smith’s work focuses on the role of astrocytes, specialized star-shaped glial cells, in modulating synaptic plasticity via norepinephrine. Conventional thinking describes astrocytes as support cells but, according to Smith, astrocytes are turning out to be more instrumental.

Norepinephrine, a neurotransmitter that plays an essential role in attention and focus, is released by a process known as volume transmission, which is a widespread release of a neurotransmitter at once, says Smith, a principal investigator in Children’s Center for Neuroscience Research. Astrocytes, which outnumber neurons in the brain, are strategically and anatomically located to receive this diffuse input and translate it into action to modulate neural networks.

“We hypothesize that astrocytes are integral, functional partners with norepinephrine in modulating cortical networks,” Smith adds. “Since astrocytes and norepinephrine have been implicated in many central nervous system functions, including learning and attention, it is critical to define mechanistically how astrocytes and norepinephrine work together to influence neural networks. This knowledge also will be important for the development of novel therapeutics to treat diseases such as attention deficit hyperactivity disorder and epilepsy.”

Nathan Smith

Sounding the alarm on fluorescent calcium dyes

“This study serves as a warning to other neuroscientists,” says Nathan A. Smith, Ph.D., a new principal investigator in the Center for Neuroscience Research at Children’s National Health System and first author of the study.

Scientists using chemical based fluorescent dyes to study the calcium dynamics of the cells within the central nervous system suspected that something external was disrupting normal cell function in their studies.

Neuroscientists at the University of Rochester Medical Center and Children’s National Health System have confirmed their suspicions by capturing data that shows, for the first time, how these fluorescent calcium dyes are causing cell damage when loaded over an extended period of time.  Their findings appeared in Science Signaling.

“This study serves as a warning to other neuroscientists,” says Nathan A. Smith, Ph.D., a new principal investigator in the Center for Neuroscience Research at Children’s National Health System and first author of the study. “As many of my colleagues have noted, we’ve known that something was going on, but now, we have evidence that the longer these dyes stay in cells, or the longer time it takes to load them into cells, the more problems we see with normal cell function.”

The study comparatively analyzed the effects of chemical and genetically encoded calcium ion indicators on cellular functions, which had not been previously performed. The outcomes showed that all of the fluorescent calcium dyes, including Fluo-4, Rhod-2, and FURA-2, had negative consequences for a number of cellular functions. For example, the dyes inhibited the sodium potassium pump (Na,K-ATPase), a membrane protein essential for many cellular membrane functions including the exchange between intracellular sodium ions (Na+) and extracellular potassium ions (K+). Inhibiting the Na,K-ATPase process results in the buildup of K+ ions in the synapses, leading to errant neural firing that has been linked to a number of disorders, including epilepsy. Additional observed impacts of exposure to the dyes included reduced cell viability, decreased glucose uptake, increased lactate release and cell swelling.

“Now, our field needs to take a step back and reevaluate findings that may have been influenced by these chemical trackers, to make sure that our observations were driven by our intended manipulations and not this additional factor,” Dr. Smith continues.

Non-chemical alternatives

Tracking calcium ions and their dynamics within the central nervous system through fluorescent calcium indicators is the primary method of measuring glial activity and glial interactions with other cell types. Unlike neurons, glial cells are electrically non-excitable; therefore electrical-based recording methods used to measure neuronal activity are ineffective.

In recent years, neuroscientists have developed additional methods to track calcium ions: genetically encoded calcium indicators (GECIs), which have grown in use since 2008. These GECIs have evolved over the years to have higher signal to noise ratios, target specific cell types and sub-compartments, and remain stable over time.*

Dr. Smith’s lab uses GECIs exclusively to monitor the calcium dynamics of glial brain cells called astrocytes as well as their interactions with other cells such as neurons. His work now seeks to understand how those interactions influence neural networks and how they operate differently in neurodevelopmental disorders, including attention-deficit hyperactivity disorder (ADHD), epilepsy and others.

“Our field has continued using these traditional calcium indicator dyes in labs because they are familiar and affordable,” Dr. Smith notes. “Our findings are a clear call to action that it’s time to revisit some of those approaches in favor of new technology.”