Posts

Vittorio Gallo

Neurodevelopmental disorders: Developing medical treatments

Vittorio Gallo

Vittorio Gallo, Ph.D., Chief Research Officer, participates in the world’s largest general scientific gathering, leading panelists in a timely conversation about progress made so far with neurodevelopmental disorders and challenges that lie ahead.

The human brain is the body’s operating system. Imagine if rogue code worked its way into its hardware and software, delaying some processes, disrupting others, wreaking general havoc.

Neurodevelopmental disorders are like that errant code. They can occur early in life and impact brain development for the rest of the person’s life. Not only can fundamental brain development go awry, processes that refine the brain also can become abnormal, creating a double neural hit.  Adding to those complications, children with neurodevelopmental disorders like autism spectrum disorder (ASD) and Fragile X syndrome often contend with multiple, overlapping cognitive impairments and learning disabilities.

The multiple layers of complexities for these disorders can make developing effective medical treatments particularly challenging, says Vittorio Gallo, Ph.D., Chief Research Officer at Children’s National Health System and recipient of a coveted Senator Jacob Javits Award in the Neurosciences.

During the Feb. 16, 2019, “Neurodevelopmental Disorders: Developing Medical Treatments” symposium, Gallo will guide esteemed panelists in a timely conversation about progress made so far and challenges that lie ahead during the AAAS Annual Meeting in Washington, the world’s largest general scientific gathering.

“This is a very important symposium; we’re going to put all of the open questions on the table,” says Gallo. “We’re going to present a snapshot of where the field is right now: We’ve made incredible advances in developmental neuroscience, neonatology, neurology, diagnostic imaging and other related fields. The essential building blocks are in place. Where are we now in developing therapeutics for these complex disorders?”

For select disorders, many genes have been identified, and each new gene has the potential to become a target for improved therapies. However, for other neurodevelopmental disorders, like ASD, an array of new genes continue to be discovered, leaving an unfinished picture of which genetic networks are of most importance.

Gallo says the assembled experts also plan to explore major research questions that remain unanswered as well as how to learn from past experiences to make future studies more powerful and insightful.

“One topic up for discussion will be new preclinical models that have the potential to help in identifying specific mechanisms that cause these disorders. A combination of genetic, biological, psychosocial and environmental risk factors are being combined in these preclinical models,” Gallo says.

“Our studies of the future need to move beyond describing and observing in order to transform into studies that establish causality between the aberrant developmental processes and these constellations of neurodevelopmental disorders.”

Study authors Aaron Sathyanesan, Ph.D., Joseph Abbah, B.Pharm., Ph.D., Srikanya Kundu, Ph.D. and Vittorio Gallo, Ph.D.

Children’s perinatal hypoxia research lauded

Study authors Aaron Sathyanesan, Ph.D., Joseph Abbah, B.Pharm., Ph.D., Srikanya Kundu, Ph.D. and Vittorio Gallo, Ph.D.

Study authors Aaron Sathyanesan, Ph.D., Joseph Abbah, B.Pharm., Ph.D., Srikanya Kundu, Ph.D. and Vittorio Gallo, Ph.D.

Chronic sublethal hypoxia is associated with locomotor miscoordination and long-term cerebellar learning deficits in a clinically relevant model of neonatal brain injury, according to a study led by Children’s National Health System researchers published by Nature Communications. Using high-tech optical and physiological methods that allow researchers to turn neurons on and off and an advanced behavioral tool, the research team found that Purkinje cells fire significantly less often after injury due to perinatal hypoxia.

The research team leveraged a fully automated, computerized apparatus – an Erasmus Ladder – to test experimental models’ adaptive cerebellar locomotor learning skills, tracking their missteps as well as how long it took the models to learn the course.

The research project, led by Aaron Sathyanesan, Ph.D., a Children’s postdoctoral research fellow, was honored with a F1000 primevery good rating.” The Children’s research team used both quantitative behavior tests and electrophysiological assays, “a valuable and objective platform for functional assessment of targeted therapeutics in neurological disorders,” according to the recommendation on a digital forum in which the world’s leading scientists and clinicians highlight the best articles published in the field.

Calling the Erasmus Ladder an “elegant” behavioral system, Richard Lu, Ph.D., and Kalen Berry write that the Children’s National Health System research team “revealed locomotor behavior and cerebellar learning deficits, and further utilized multielectrode recording/optogenetics approaches to define critical pathophysiological features, such as defects in Purkinje cell firing after neonatal brain injury.”

Lu, Beatrice C. Lampkin Endowed Chair in Cancer Epigenetics, and Berry, an associate faculty member in the Cancer and Blood Diseases Institute, both at Cincinnati Children’s, note that the Children’s results “suggest that GABA signaling may represent a potential therapeutic target for hypoxia-related neonatal brain injury that, if provided at the correct time during development post-injury, could offer lifelong improvements.”

In addition to Sathyanesan, Children’s co-authors include Co-Lead Author, Srikanya Kundu, Ph.D., and Joseph Abbah, both of Children’s Center for Neuroscience Research, and Vittorio Gallo, Ph.D., Children’s Chief Research Officer and the study’s senior author.

Research covered in this story was supported by the Intellectual and Developmental Disability Research Center under award number U54HD090257.

Nobuyuki Ishibashi

Cortical dysmaturation in congenital heart disease

Nobuyuki Ishibashi

On Jan. 4, 2019, Nobuyuki Ishibashi, M.D., the director of the Cardiac Surgery Research Laboratory and an investigator with the Center for Neuroscience Research at Children’s National Health System, published a review in Trends in Neurosciences about the mechanisms of cortical dysmaturation, or disturbances in cortical development, that can occur in children born with congenital heart disease (CHD). By understanding the early-life impact and relationship between cardiac abnormalities and cortical neuronal development, Dr. Ishibashi and the study authors hope to influence strategies for neonatal neuroprotection, mitigating the risk for developmental delays among CHD patients.

Dr. Ishibashi answers questions about this review and CHD-neurodevelopmental research:

  1. Tell us more about your research. Why did you choose to study these interactions in this patient population?

My research focuses on studying how CHD and neonatal cardiac surgery affect the rapidly-developing brain. Many children with CHD, particularly the most complex anomalies, suffer from important behavioral anomalies and neurodevelopmental delays after cardiac surgery. As a surgeon scientist, I want to optimize treatment strategy and develop a new standard of care that will reduce neurodevelopmental impairment in our patients.

  1. How does this study fit into your larger body of work? What are a few take-home messages from this paper?

Our team and other laboratories have recently identified a persistent perinatal neurogenesis that targets the frontal cortex – the brain area responsible for higher-order cognitive functions. The main message from this article is that further understanding of the cellular and molecular mechanisms underlying cortical development and dysmaturation will likely help to identify novel strategies to treat and improve outcomes in our patients suffering from intellectual and behavioral disabilities.

  1. What do you want pediatricians and researchers to know about this study? Why is it important right now?

Although the hospital mortality risk is greatly reduced, children with complex CHD frequently display subsequent neurological disabilities affecting intellectual function, memory, executive function, speech and language, gross and fine motor skills and visuospatial functions. In addition to the impact of the neurological morbidity on the patients themselves, the toll on families and society is immense. Therefore it is crucial to determine the causes of altered brain maturation in CHD.

  1. How do you envision this research influencing future studies and pediatric health outcomes? As a researcher, how will you proceed?

In this article we placed special emphasis on the need for well-designed preclinical studies to define disturbances in cortical neurogenesis due to perinatal brain injury. I believe that further study of the impact of hypoxemia on brain development is of broad relevance — not just for children with congenital heart disease, but for other populations where intellectual and behavioral dysfunctions are a source of chronic morbidity, such as survivors of premature birth.

  1. What discoveries do you envision being at the forefront of this field?

One of the important questions is: During which developmental period, prenatal or postnatal, is the brain most sensitive to developmental and behavioral disabilities associated with hypoxemia? Future experimental models will help us study key effects of congenital cortical development anomalies on brain development in children with CHD.

  1. What impact could this research make? What’s the most striking finding and how do you think it will influence the field?

Although cortical neurogenesis at fetal and adult stages has been widely studied, the development of the human frontal cortex during the perinatal period has only recently received greater attention as a result of new identification of ongoing postnatal neurogenesis in the region responsible for important intellectual and behavioral functions. Children’s National is very excited with the discoveries because it has opened new opportunities that may lead to regeneration and repair of the dysmature cortex. If researchers identify ways to restore endogenous neurogenic abilities after birth, the risk of neurodevelopment disabilities and limitations could be greatly reduced.

  1. Is there anything else you would like to add that we didn’t ask you about? What excites you about this research?

In this article we highlight an urgent need to create a truly translational area of research in CHD-induced brain injury through further exploration and integration of preclinical models. I’m very excited about the highly productive partnerships we developed within the Center for Neuroscience Research at Children’s National, led by an internationally-renowned developmental neuroscientist, Vittorio Gallo, Ph.D., who is a co-senior author of this article. Because of our collaboration, my team has successfully utilized sophisticated and cutting-edge neuroscience techniques to study brain development in children born with CHD. To determine the causes of altered brain maturation in congenital heart disease and ultimately improve neurological function, we believe that a strong unity between cardiovascular and neuroscience research must be established.

Additional study authors include Camille Leonetti, Ph.D., a postdoctoral research fellow with the Center for Neuroscience Research and Children’s National Heart Institute, and Stephen Back, M.D., Ph.D., a professor of pediatrics at Oregon Health and Science University.

The research was supported by multiple grants and awards from the National Institutes of Health, inclusive of the National Heart Lung and Blood Institute (RO1HL139712), the National Institute of Neurological Disorders and Stroke (1RO1NS054044, R37NS045737, R37NS109478), the National Institute on Aging (1RO1AG031892-01) and the National Institute of Child Health and Human Development (U54HD090257).

Additional support for this review was awarded by the American Heart Association (17GRNT33370058) and the District of Columbia Intellectual and Developmental Disabilities Research Center, which is supported through the Eunice Kennedy Shriver National Institute of Child Health and Human Development program grant 1U54HD090257.

Vittorio Gallo

Vittorio Gallo, Ph.D., honored with Senator Jacob Javits Award in the Neurosciences

Vittorio Gallo

Vittorio Gallo, Ph.D., Children’s Chief Research Officer, has been awarded a prestigious Senator Jacob Javits Award in the Neurosciences, which extends federal funding for Gallo’s lab for at least seven years. The long-term support is offered to “investigators with a history of exceptional talent, imagination and preeminent scientific achievement.”

Only National Institute of Neurological Disorders and Stroke (NINDS) staff members or NINDS Council members may nominate researchers for the coveted awards, named in honor of Sen. Jacob Javits, (R-New York). Before his death, Sen. Javits advocated for additional research in a wide variety of disorders of the brain and nervous system.

“It’s a great recognition from the neuroscience community and from NINDS for contributions to neuroscience and outstanding service to the neuroscience community,” Gallo says. “It’s also very exciting because it gives additional national visibility to our Center for Neuroscience Research and to Children’s National Health System, as one of the nation’s leading research institutions.”

Through the award, Gallo’s successful five-year Research Project Grant from the National Institutes of Health will be converted to a seven-year award. In the fourth year of federal funding, he can apply for a budgetary increase.

“Thanks to this funding, I predict we will be able to identify cellular and molecular mechanisms that underlie developmental delays in children who experienced neonatal brain injury,” Gallo says.

“We are really starting to understand this very complex problem: How does neonatal brain injury lead to developmental delays later in a child’s life? What are the mechanisms? We know there are cognitive and behavioral abnormalities that are common to children who have experienced hypoxia as newborns. But we don’t really know how these behavioral abnormalities arise at the physiological, cellular and molecular levels.”

Gallo says identifying these cellular targets will make it possible to tailor interventions that target distinct cell types at different times in the child’s life.

Recent work by Gallo’s lab includes a research paper published online Aug. 13, 2018, by Nature Communications that found chronic sublethal hypoxia is associated with locomotor miscoordination and long-term cerebellar learning deficits in a clinically relevant model of neonatal brain injury.

toddler on a playground

Perinatal hypoxia associated with long-term cerebellar learning deficits and Purkinje cell misfiring

toddler on a playground

The type of hypoxia that occurs with preterm birth is associated with locomotor miscoordination and long-term cerebellar learning deficits but can be partially alleviated with an off-the-shelf medicine, according to a study using a preclinical model.

Oxygen deprivation associated with preterm birth leaves telltale signs on the brains of newborns in the form of alterations to cerebellar white matter at the cellular and the physiological levels. Now, an experimental model of this chronic hypoxia reveals that those cellular alterations have behavioral consequences.

Chronic sublethal hypoxia is associated with locomotor miscoordination and long-term cerebellar learning deficits in a clinically relevant model of neonatal brain injury, according to a study led by Children’s National Health System researchers published online Aug. 13, 2018, by Nature Communications. Using high-tech optical and physiological methods that allow researchers to turn neurons on and off and an advanced behavioral tool, the research team finds that Purkinje cells fire significantly less often after injury due to perinatal hypoxia. However, an off-the-shelf medicine now used to treat epilepsy enables those specialized brain cells to regain their ability to fire, improving locomotor performance.

Step out of the car onto the pavement, hop up to the level of the curb, stride to the entrance, and climb a flight of stairs. Or, play a round of tennis. The cerebellum coordinates such locomotor performance and muscle memory, guiding people of all ages as they adapt to a changing environment.

“Most of us successfully coordinate our movements to navigate the three-dimensional spaces we encounter daily,” says Vittorio Gallo, Ph.D., Children’s Chief Research Officer and the study’s senior author. “After children start walking, they also have to learn how to navigate the environment and the spaces around them.”

These essential tasks, Gallo says, are coordinated by Purkinje cells, large neurons located in the cerebellum that are elaborately branched like interlocking tree limbs and represent the only source of output for the entire cerebellar cortex. The rate of development of the fetal cerebellum dramatically increases at a time during pregnancy that often coincides with preterm birth, which can delay or disrupt normal brain development.

“It’s almost like a short circuit. Purkinje cells play a very crucial role, and when the frequency of their firing is diminished by injury the whole output of this brain region is impaired,” Gallo says. “For a family of a child who has this type of impaired neural development, if we understand the nature of this disrupted circuitry and can better quantify it, in terms of locomotor performance, then we can develop new therapeutic approaches.”

Study authors Aaron Sathyanesan, Ph.D., Joseph Abbah, B.Pharm., Ph.D., Srikanya Kundu, Ph.D. and Vittorio Gallo, Ph.D.

The research team leveraged a fully automated, computerized apparatus that looks like a ladder placed on a flat surface, encased in glass, with a darkened box at either end. Both the hypoxic and control groups had training sessions during which they learned how to traverse the horizontal ladder, coaxed out of the darkened room by a gentle puff of air and a light cue. Challenge sessions tested their adaptive cerebellar locomotor learning skills. The pads they strode across were pressure-sensitive and analyzed individual stepping patterns to predict how long it should take each to complete the course.

During challenge sessions, obstacles were presented in the course, announced by an audible tone. If learning was normal, then the response to the tone paired with the obstacle would be a quick adjustment of movement, without breaking stride, says Aaron Sathyanesan, Ph.D., co-lead author. Experimental models exposed to perinatal hypoxia showed significant deficits in associating that tone with the obstacle.

“With the control group, we saw fewer missteps during any given trial,” Sathyanesan says. “And, when they got really comfortable, they took longer steps. With the hypoxic group, it took them longer to learn the course. They made a significantly higher number of missteps from day one. By the end of the training period, they could walk along all of the default rungs, but it took them longer to learn how to do so.”

Purkinje cells fire two different kinds of spikes. Simple spikes are a form of constant activity as rhythmic and automatic as a heartbeat. Complex spikes, by contrast, occur less frequently. Sathyanesan and co-authors say that some of the deficits that they observed were due to a reduction in the frequency of simple spiking.

Two weeks after experiencing hypoxia, the hypoxic group’s locomotor performance remained significantly worse than the control group, and delays in learning could still be seen five weeks after hypoxia.

Gamma-aminobutyric acid (GABA), a neurotransmitter, excites immature neurons before and shortly after birth but soon afterward switches to having an inhibitory effect within in the cerebellum, Sathyanesan says. The research team hypothesizes that reduced levels of excitatory GABA during early development leads to long-term motor problems. Using an off-the-shelf drug to increase GABA levels immediately after hypoxia dramatically improved locomotor performance.

“Treating experimental models with tiagabine after hypoxic injury elevates GABA levels, partially restoring Purkinje cells’ ability to fire,” Gallo says. “We now know that restoring GABA levels during this specific window of time has a beneficial effect. However, our approach was not specifically targeted to Purkinje cells. We elevated GABA everywhere in the brain. With more targeted and selective administration to Purkinje cells, we want to gauge whether tiagabine has a more powerful effect on normalizing firing frequency.”

In addition to Gallo and Sathyanesan, Children’s co-authors include Co-Lead Author, Srikanya Kundu, Ph.D., and Joseph Abbah, B.Pharm., Ph.D., both of Children’s Center for Neuroscience Research.

Research covered in this story was supported by the Intellectual and Developmental Disability Research Center under award number U54HD090257.

Research and Education Week awardees embody the diverse power of innovation

cnmc-research-education-week

“Diversity powers innovation” was brought to life at Children’s National April 16 to 20, 2018, during the eighth annual Research and Education Week. Children’s faculty were honored as President’s Award winners and for exhibiting outstanding mentorship, while more than 360 scientific poster presentations were displayed throughout the Main Atrium.

Two clinical researchers received Mentorship Awards for excellence in fostering the development of junior faculty. Lauren Kenworthy, Ph.D received the award for Translational Science and Murray M. Pollack, M.D., M.B.A., was recognized in the Clinical Science category as part of Children’s National Health System’s Research and Education Week 2018.

Dr. Kenworthy has devoted her career to improving the lives of people on the autism spectrum and was cited by former mentees as an inspirational and tireless counselor. Her mentorship led to promising new lines of research investigating methods for engaging culturally diverse families in autism studies, as well as the impact of dual language exposure on cognition in autism.

Meanwhile, Dr. Pollack was honored for his enduring focus on motivating early-career professionals to investigate outcomes in pediatric critical care, emergency medicine and neonatology. Dr. Pollack is one of the founders of the Collaborative Pediatric Critical Care Research Network. He developed PRISM 1 and 2, which has revolutionized pediatric intensive care by providing a methodology to predict mortality and outcome using standardly collected clinical data. Mentees credit Dr. Pollack with helping them develop critical thinking skills and encouraging them to address creativity and focus in their research agenda.

In addition to the Mentorship and President’s Awards, 34 other Children’s National faculty, residents, interns and research staff were among the winners of Poster Presentation awards. The event is a celebration of the commitment to improving pediatric health in the form of education, research, scholarship and innovation that occurs every day at Children’s National.

Children’s Research Institute (CRI) served as host for the week’s events to showcase the breadth of research and education programs occurring within the entire health system, along with the rich demographic and cultural origins of the teams that make up Children’s National. The lineup of events included scientific poster presentations, as well as a full slate of guest lectures, educational workshops and panel discussions.

“It’s critical that we provide pathways for young people of all backgrounds to pursue careers in science and medicine,” says Vittorio Gallo, Ph.D., Children’s chief research officer and CRI’s scientific director. “In an accelerated global research and health care environment, internationalization of innovation requires an understanding of cultural diversity and inclusion of different mindsets and broader spectrums of perspectives and expertise from a wide range of networks,” Gallo adds.

“Here at Children’s National we want our current and future clinician-researchers to reflect the patients we serve, which is why our emphasis this year was on harnessing diversity and inclusion as tools to power innovation,” says Mark L. Batshaw, M.D., physician-in-chief and chief academic officer of Children’s National.

“Research and Education Week 2018 presented a perfect opportunity to celebrate the work of our diverse research, education and care teams, who have come together to find innovative solutions by working with local, national and international partners. This event highlights the ingenuity and inspiration that our researchers contribute to our mission of healing children,” Dr. Batshaw concludes.

Awards for the best posters were distributed according to the following categories:

  • Basic and translational science
  • Quality and performance improvement
  • Clinical research
  • Community-based research and
  • Education, training and program development.

Each winner illustrated promising advances in the development of new therapies, diagnostics and medical devices.

Diversity powers innovation: Denice Cora-Bramble, M.D., MBA
Diversity powers innovation: Vittorio Gallo, Ph.D.
Diversity powers innovation: Mark L. Batshaw, M.D.

Vittorio Gallo

Perinatal brain injury headlines American Society for Neurochemistry

Vittorio Gallo

Dr. Gallo’s research could have major implications for overcoming the common behavioral and developmental challenges associated with premature birth.

Children’s National Chief Research Officer Vittorio Gallo, Ph.D., recently had the honor of presenting a presidential lecture at the 48th Annual Meeting of the American Society for Neurochemistry (ASN). The lecture focused on his lifelong investigations of the cellular and molecular mechanisms of white matter development and injury, including myelin and glial cells – which are involved in the brain’s response to injury.

Specifically, he outlined the underlying diffuse white matter injury observed in his lab’s pre-clinical model of perinatal hypoxia, and presented new, non-invasive interventions that promote functional recovery and attenuate developmental delay after perinatal injury in the model. Diffuse white matter injuries are the most frequently observed pattern of brain injury in contemporary cohorts of premature infants. Illuminating methods that might stimulate growth and repair of such injuries shows promise for potential noninvasive strategies that might mitigate the long-term behavioral abnormalities and developmental delay associated with premature birth.

Dr. Gallo’s work in developmental neuroscience has been seminal in deepening understanding of cerebral palsy and multiple sclerosis. During his tenure as center director, he transformed the Center for Neuroscience Research into one of the nation’s premier programs.

ASN gathers nearly 400 delegates from the neurochemistry sector each year, including bench and clinical scientists, principal investigators, graduate students and postdoctoral fellows all actively involved in research from North America and around the world.

Vittorio Gallo

How the environment helps to shape the brain

Vittorio Gallo

“The strength, duration and timing of environmental experience influences plasticity in brain circuitry, which is made up of communication cables called axons that link neurons throughout the brain and are coated by myelin, a fatty substance that helps nerve impulses speed from place to place,” says Vittorio Gallo, Ph.D., Chief Research Officer at Children’s National and senior study author.

Researchers have long known that babies of all kinds need to be exposed to rich, complex environments for optimal brain health and potential. Exposure to new sights, sounds and other sensory experiences appears to be critical for strengthening infants’ developing brains and encouraging smoothly running neural networks. Until recently, little was known about the biological mechanisms behind this phenomenon.

In a review article published online Aug. 22, 2017 in Trends in Neurosciences, Children’s National Health System researchers discuss the role of environmental stimuli on the development of myelin—the fatty insulation that surrounds the extensions that connect cells throughout the nervous system and make up a large part of the brain’s white matter. Positive influences, such as exposure to a large vocabulary and novel objects, can boost the growth of myelin. Conversely, negative influences, such as neglect and social isolation, can harm it, potentially altering the course of brain development.

“The strength, duration and timing of environmental experience influences plasticity in brain circuitry, which is made up of communication cables called axons that link neurons throughout the brain and are coated by myelin, a fatty substance that helps nerve impulses speed from place to place,” says Vittorio Gallo, Ph.D., Chief Research Officer at Children’s National and senior study author. “As it responds to environmental stimuli, the brain continually shores up myelin’s integrity. Just as important, damaged myelin can leave gaps in the neural network which can lead to cognitive, motor and behavioral deficits.”

According to Gallo and study lead author Thomas A. Forbes, a pool of oligodendrocyte progenitor cells (OPCs) specialize in making myelin and do so from childhood into adulthood. The resulting oligodendrocyte cells (OLs) form an important working partnership with axons. From approximately 23 to 37 weeks’ gestation, OLs develop in the fetal brain and they continue to be generated after birth until adolescence.

“This dynamic feedback loop between myelin plasticity and neuronal excitability is crucial,” Forbes says. “It helps to strengthen motor and cognitive function and permits children and adults to learn new skills and to record new memories.”

In utero, genetics plays an outsized role in the initial structure of white matter, which is located in the subcortical region of the brain and takes its white color from myelin, the lipid and protein sheath that electrically insulates nerve cells. Defects in the microstructural organization of white matter are associated with many neurodevelopmental disorders. Once infants are born, environmental experiences also can begin to exert a meaningful role.

“The environment can be viewed as a noninvasive therapeutic approach that can be employed to bolster white matter health, either on its own or working in tandem with pharmacologic therapies,” Gallo adds. “The question is how to design the best environment for infants and children to grow and to achieve the highest cognitive function. An enriched environment not only involves the opportunity to move and participate in physical exercise and physical therapy; it is also an environment where there is novelty, new experiences and continuously active learning. It is equally important to minimize social stressors. It’s all about the balance.”

Among the potential interventions to boost brain power, independent of socioeconomic status:

  • Exposing children to new and different objects with an opportunity for physical activity and interaction with a number of playmates. This type of setting challenges the child to continuously adapt to his or her surroundings in a social, physical and experiential manner. In experimental models, enriched environments supported brain health by increasing the volume and length of myelinated fibers, the volume of myelin sheaths and by boosting total brain volume.
  • Exposure to music helps with cognition, hearing and motor skills for those who play an instrument, tapping multiple areas of the brain to work together collaboratively. Diffusion tensor imaging (DTI) reveals that professional pianists who began playing as children have improved white matter integrity and plasticity, Gallo and Forbes
  • At its heart, active learning requires interacting with and adapting to the environment. Generating new OLs influences learning new motor skills in the very young as well as the very old. And cognitive training and stimulation shapes and preserves white matter integrity in the aging.
  • DTI studies indicate that four weeks of integrative mind-body training alters myelination and improves white matter efficiency with especially pronounced changes in the area of the brain responsible for self-regulation, impulse control and emotion.
  • Voluntary exercise in experimental models is associated with OPCs differentiating into mature OLs. Imaging studies show a positive relationship between physical fitness, white matter health and the brain networks involved in memory.

Conversely, such negative influences as premature birth, poor nutrition, disease, neglect and social isolation can degrade myelin integrity, compromising the person’s ability to carry out basic motor skills and cognitive function. Usually, the pool of OPCs expands as the fetus is about to be born. But brain injury, lack of oxygen and restricted blood supply can delay maturation of certain brain cells and can cause abnormalities in white matter that diminish the brain’s capacity to synthesize myelin. Additional white matter insults can be caused by use of anesthesia and stress, among other variables.

The environmental influence has the potential to be “the Archimedes’ Lever to appropriating WM development among a limited range of only partially efficacious treatment options,” the authors conclude.

A sirtuin might help repair a common neonatal brain injury

Sirtuin could repair common neonatal brain injury

A sirtuin might help repair a common neonatal brain injury

A team of researchers  investigated the molecular mechanisms behind oligodendrocyte progenitor cell proliferation in neonatal hypoxia.

What’s known

Hypoxia, or a lack of oxygen, is a major cause of diffuse white matter injury (DWMI). This condition leads to permanent developmental disabilities in prematurely born infants. The long-term abnormalities of the brain’s white matter that characterize DWMI are caused by the loss of a specific type of cells known as oligodendrocytes, which support nerve cells and produce myelin, a lipid and protein sheath that electrically insulates nerve cells. Oligodendrocytes are produced by a population of immature cells known as oligodendrocyte progenitor cells (OPCs). Previous research has shown that hypoxia can trigger OPCs to proliferate and presumably produce new oligodendrocytes. The molecular pathways that hypoxia triggers to make new OPCs remain unclear.

What’s new

A team of researchers led by Vittorio Gallo, Ph.D., director of the Center for Neuroscience Research and the Intellectual and Developmental Disabilities Research Center at Children’s National Health System, investigated the molecular mechanisms behind what prompts OPCs to proliferate in a preclinical model of neonatal hypoxia. The researchers found that a molecule known as Sirt1 acts as a major regulator of OPC proliferation and regeneration. Sirt1 is a sirtuin, a class of molecules that has attracted interest over the past several years for its role in stem cells, aging and inflammation. Hypoxia appears to induce Sirt1 formation. When the researchers prevented brain tissues in petri dishes from making Sirt1 or removed this molecule in preclinical models, these actions prevented OPC proliferation. What’s more, preventing Sirt1 production also inhibited OPCs from making oligodendrocytes. These findings suggest that Sirt1 is essential for replacing oligodendrocytes to repair DWMI after hypoxia. Additionally, finding ways to enhance Sirt1 activity eventually could provide a novel way to help infants recover after hypoxia and prevent DWMI.

Questions for future research

Q: How can Sirt1 activity be enhanced in preclinical models and humans?
Q: Can deficits triggered by diffuse white matter injury be prevented or reversed with Sirt1?
Q: Which other treatments might be useful for diffuse white matter injury?

Source: Sirt1 regulates glial progenitor proliferation and regeneration in white matter after neonatal brain injury.” Jablonska, M., M. Gierdalski, L. Chew, T. Hawley, M. Catron, A. Lichauco, J. Cabrera-Luque, T. Yuen, D. Rowitch and V. Gallo. Published by Nature Communications on Dec. 19, 2016.

Congenital heart disease and cortical growth

The cover of  Science Translational Medicine features a new study of the cellular-level changes in the brain induced by congenital heart disease. Reprinted with permission from AAAS. Not for download

Disruptions in cerebral oxygen supply caused by congenital heart disease have significant impact on cortical growth, according to a research led by Children’s National Health System. The findings of the research team, which include co-authors from the National Institutes of Health, Boston Children’s Hospital and Johns Hopkins School of Medicine, appear on the cover of Science Translational Medicine. The subventricular zone (SVZ) in normal newborns’ brains is home to the largest stockpile of neural stem/progenitor cells, with newly generated neurons migrating from this zone to specific regions of the frontal cortex and differentiating into interneurons. When newborns experience disruptions in cerebral oxygen supply due to congenital heart disease, essential cellular processes go awry and this contributes to reduced cortical growth.

The preliminary findings point to the importance of restoring these cells’ neurogenic potential, possibly through therapeutics, to lessen children’s long-­term neurological deficits.

“We know that congenital heart disease (CHD) reduces cerebral oxygen at a time when the developing fetal brain most needs oxygen. Now, we are beginning to understand the mechanisms of CHD-­induced brain injuries at a cellular level, and we have identified a robust supply of cells that have the ability to travel directly to the site of injury and potentially provide help by replacing lost or damaged neurons,” says Nobuyuki Ishibashi, M.D., Director of the Cardiac Surgery Research Laboratory at Children’s National, and co­-senior study author.

The third trimester of pregnancy is a time of dramatic growth for the fetal brain, which expands in volume and develops complex structures and network connections that growing children rely on throughout adulthood. According to the National Heart, Lung, and Blood Institute, congenital heart defects are the most common major birth defect, affecting 8 in 1,000 newborns. Infants born with CHD can experience myriad neurological deficits, including behavioral, cognitive, social, motor and attention disorders, the research team adds.

Cardiologists have tapped non­invasive imaging to monitor fetal hearts during gestation in high-­risk pregnancies and can then perform corrective surgery in the first weeks of life to fix damaged hearts. Long­ term neurological deficits due to immature cortical development also have emerged as major challenges in pregnancies complicated by CHD.

“I think this is an enormously important paper for surgeons and for children and families who are affected by CHD. Surgeons have been worried for years that the things we do during corrective heart surgery have the potential to affect the development of the brain. And we’ve learned to improve how we do heart surgery so that the procedure causes minimal damage to the brain. But we still see some kids who have behavioral problems and learning delays,” says Richard A. Jonas, M.D., Chief of the Division of Cardiac Surgery at Children’s National, and co-­senior study author. “We’re beginning to understand that there are things about CHD that affect the development of the brain before a baby is even born. What this paper shows is that the low oxygen level that sometimes results from a congenital heart problem might contribute to that and can slow down the growth of the brain. The good news is that it should be possible to reverse that problem using the cells that continue to develop in the neonate’s brain after birth.”

Among preclinical models, the spatiotemporal progression of brain growth in this particular model most closely parallels that of humans. Likewise, the SVZ cytoarchitecture of the neonatal preclinical model exposed to hypoxia mimics that of humans in utero and shortly after birth. The research team leveraged CellTracker Green to follow the path traveled by SVZ­ derived cells and to illuminate their fate, with postnatal SVZ supplying the developing cortex with newly generated neurons. SVZ­ derived cells were primarily neuroblasts. Superparamagnetic iron oxide nanoparticles supplied answers about long­ term SVZ migration, with SVZ ­derived cells making their way to the prefrontal cortex and the somatosensory cortex of the brain.

“We demonstrated that in the postnatal period, newly generated neurons migrate from the SVZ to specific cortices, with the majority migrating to the prefrontal cortex,” says Vittorio Gallo, Ph.D., Director of the Center for Neuroscience Research at Children’s National, and co­-senior study author. “Of note, we revealed that the anterior SVZ is a critical source of newborn neurons destined to populate the upper layers of the cortex. We challenged this process through chronic hypoxia exposure, which severely impaired neurogenesis within the SVZ, depleting this critical source of interneurons.”

In the preclinical model of hypoxia as well as in humans, brains were smaller, weighed significantly less and had a significant reduction in cortical gray matter volume. In the prefrontal cortex, there was a significant reduction in white matter neuroblasts. Taken as a whole, according to the study authors, the findings suggest that impaired neurogenesis within the SVZ represents a cellular mechanism underlying hypoxia ­induced, region ­specific reduction in immature neurons in the cortex. The prefrontal cortex, the region of the brain that enables such functions as judgment, decision­ making and problem solving, is most impacted. Impairments in higher ­order cognitive functions involving the prefrontal cortex are common in patients with CHD.

This is the consequential malfunction of the brain during congenital heart defects.

Congenital heart disease and white matter injury

This is the consequential malfunction of the brain during congenital heart defects.

Although recent advances have greatly improved the survival of children with congenital heart disease, up to 55 percent will be left with injury to their brain’s white matter – an area that is critical for aiding connection and communication between various regions in the brain.

What’s known

Eight of every 1,000 children born each year have congenital heart disease (CHD). Although recent advances have greatly improved the survival of these children, up to 55 percent will be left with injury to their brain’s white matter – an area that is critical for aiding connection and communication between various regions in the brain. The resulting spectrum of neurological deficits can have significant costs for the individual, their family and society. Although studies have demonstrated that white matter injuries due to CHD have many contributing factors, including abnormal blood flow to the fetal brain, many questions remain about the mechanisms that cause these injuries and the best interventions.

What’s new

A Children’s National Health System research team combed existing literature, reviewing studies from Children’s as well as other research groups, to develop an article detailing the current state of knowledge on CHD and white matter injury. The scientists write that advances in neuroimaging – including magnetic resonance imaging, magnetic resonance spectroscopy, Doppler ultrasound and diffusion tensor imaging – have provided a wealth of knowledge about brain development in patients who have CHD. Unfortunately, these techniques alone are unable to provide pivotal insights into how CHD affects cells and molecules in the brain. However, by integrating animal models with findings in human subjects and in postmortem human tissue, the scientists believe that it will be possible to find novel therapeutic targets and new standards of care to prevent developmental delay associated with cardiac abnormalities.

For example, using a porcine model, the Children’s team was able to define a strategy for white matter protection in congenital heart surgery through cellular and developmental analysis of different white matter regions. Another study from Children’s combined rodent hypoxia with a brain slice model to replicate the unique brain conditions in neonates with severe and complex congenital heart disease. This innovative animal model provided novel insights into the possible additive effect of preoperative hypoxia on brain insults due to cardiopulmonary bypass and deep hypothermic circulatory arrest.

The Children’s research team also recently published an additional review article describing the key windows of development during which the immature brain is most vulnerable to CHD-related injury.

Questions for future research

Q: Can we create an animal model that recapitulates the morphogenic and developmental aspects of CHD without directly affecting other organs or developmental processes?
Q: What are the prenatal and neonatal cellular responses to CHD in the developing brain?
Q: What are the molecular mechanisms underlying white matter immaturity and vulnerability to CHD, and how can we intervene?
Q: How can we accurately assess the dynamic neurological outcomes of CHD and/or corrective surgery in animal models?
Q: Prenatal or postnatal insults to the developing brain: which is most devastating in regards to developmental and behavioral disabilities?
Q: How can we best extrapolate from, and integrate, neuroimaging findings/correlations in human patients with cellular/molecular approaches in animal models?

Source: Reprinted from Trends in Neurosciences, Vol. 38/Ed. 6, Paul D. Morton, Nobuyuki Ishibashi, Richard A. Jonas and Vittorio Gallo, “Congenital cardiac anomalies and white matter injury,” pp. 353-363, Copyright 2015, with permission from Elsevier.

Vittorio Gallo

Vittorio Gallo named Chief Research Officer

Vittorio Gallo

As chief research officer, Vittorio Gallo, Ph.D., will be instrumental in developing and realizing Children’s Research Institute’s long-term strategic vision.

Children’s National Health System has appointed the longtime director of its Center for Neuroscience Research, Vittorio Gallo, Ph.D., as Chief Research Officer. Gallo’s appointment comes at a pivotal time for the institution’s research strategic plan, as significant growth and expansion will occur in the next few years. Gallo is a neuroscientist who studies white matter disorders, with particular focus on white matter growth and repair. He is also the Wolf-Pack Chair in Neuroscience at Children’s Research Institute, the academic arm of Children’s National.

As Chief Research Officer, Gallo will be instrumental in developing and realizing Children’s Research Institute’s long-term strategic vision, which includes building out the nearly 12-acre property once occupied by Walter Reed National Military Medical Center to serve as a regional innovation hub and to support Children’s scientists conducting world-class pediatric research in neuroscience, genetics, clinical and translational science, cancer and immunology. He succeeds Mendel Tuchman, M.D., who has had a long and distinguished career as Children’s Chief Research Officer for the past 12 years and who will remain for one year in an emeritus role, continuing federally funded research projects and mentoring junior researchers.

“I am tremendously pleased that Vittorio has agreed to become Chief Research Officer as of July 1, 2017, at such a pivotal time in Children’s history,” says Mark L. Batshaw, M.D., Physician-in-Chief and Chief Academic Officer at Children’s National. “Since Mendel announced plans to retire last summer, I spent a great deal of time talking to Children’s Research Institute investigators and leaders and also asking colleagues around the nation about the type of person and unique skill sets needed to serve as Mendel’s successor. With each conversation, it became increasingly clear that the most outstanding candidate for the Chief Research Officer position already works within Children’s walls,” Dr. Batshaw adds.

“I am deeply honored by being selected as Children’s next Chief Research Officer and am excited about being able to play a leadership role in defining the major areas of research that will be based at the Walter Reed space. The project represents an incredible opportunity to maintain the core nucleus of our research strengths – genetics, immunology, neurodevelopmental disorders and disabilities – and to expand into new, exciting areas of research. What’s more, we have an unprecedented opportunity to form new partnerships with peers in academia and private industry, and forge new community partnerships,” Gallo says. “I am already referring to this as Walter Reed ‘Now,’ so that we are not waiting for construction to begin to establish these important partnerships.”

Gallo’s research focus has been on white matter development and injury, myelin and glial cells – which are involved in the brain’s response to injury. His past and current focus is also on neural stem cells. His work in developmental neuroscience has been seminal in deepening understanding of cerebral palsy and multiple sclerosis. He came to Children’s National from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) intramural program. His intimate knowledge of the workings of the National Institutes of Health (NIH) has helped him to establish meaningful collaborations between both institutions. During his tenure, he has transformed the Center for Neuroscience Research into one of the nation’s premier programs. The Center is home to the prestigious NIH/NICHD-funded District of Columbia Intellectual and Developmental Disabilities Research Center, which Gallo directs.

Children’s research scientists working under the auspices of Children’s Research Institute conduct and promote highly collaborative and multidisciplinary research within the hospital that aims to better understand, treat and, ultimately, prevent pediatric disease. As Chief Research Officer, Gallo will continue to establish and enhance collaborations between research and clinical programs. Such cross-cutting projects will be essential in defining new mechanisms that underlie pediatric disease. “We know, for instance, that various mechanisms contribute to many genetic and neurological pediatric diseases, and that co-morbidities add another layer of complexity. Tapping expertise across disciplines has the potential to unravel current mysteries, as well as to better characterize unknown and rare diseases,” he says.

“Children’s National is among the nation’s top seven pediatric hospitals in NIH research funding, and the extraordinary innovations that have been produced by our clinicians and scientists have been put into practice here and in hospitals around the world,” Dr. Batshaw adds. “Children’s leadership aspires to nudge the organization higher, to rank among the nation’s top five pediatric hospitals in NIH research funding.”

Gallo says the opportunity for Children’s research to expand beyond the existing buildings and the concurrent expansion into new areas of research will trigger more hiring. “We plan to grow our research enterprise through strategic hires and by attracting even more visiting investigators from around the world. By expanding our community of investigators, we aim to strengthen our status as one of the nation’s leading pediatric hospitals,” he says.

Harnessing progenitor cells in neonatal white matter repair

The sirtuin protein Sirt1 plays a crucial role in the proliferation and regeneration of glial cells from an existing pool of progenitor cells — a process that rebuilds vital white matter following neonatal hypoxic brain injury. Although scientists do not fully understand Sirt1’s role in controlling cellular proliferation, this pre-clinical model of neonatal brain injury outlines for the first time how Sirt1 contributes to development of additional progenitor cells and maturation of fully functional oligodendrocytes.

The findings, published December 19 in Nature Communications, suggest that modulation of this protein could enhance progenitor cell regeneration, spurring additional white matter growth and repair following neonatal brain injury.

“It is not a cure. But, in order to regenerate the white matter that is lost or damaged, the first steps are to identify endogenous cells capable of regenerating lost cells and then to expand their pool. The glial progenitor cells represent 4 to 5 percent of total brain cells,” says Vittorio Gallo, Ph.D., Director of the Center for Neuroscience Research at Children’s National, and senior author of the study. “It’s a sizable pool, considering that the brain is made up of billions of cells. The advantage is that these progenitor cells are already there, with no requirement to slip them through the blood-brain barrier. Eventually they will differentiate into oligodendrocyte cells in white matter, mature glia, and that’s exactly what we want them to do.”

The study team identified Sirt1 as a novel, major regulator of basal oligodendrocyte progenitor cell (OPC) proliferation and regeneration in response to hypoxia in neonatal white matter, Gallo and co-authors write. “We demonstrate that Sirt1 deacetylates and activates Cdk2, a kinase which controls OPC expansion. We also elucidate the mechanism by which Sirt1 targets other individual members of the Cdk2 signaling pathway, by regulating their deacetylation, complex formation and E2F1 release, molecular events which drive Cdk2-mediated OPC proliferation,” says Li-Jin Chew, Ph.D., research associate professor at Children’s Center for Neuroscience Research and a study co-author.

Hypoxia-induced brain injury in neonates initiates spontaneous amplification of progenitor cells but also causes a deficiency of mature oligodendrocytes. Inhibiting Sirt1 expression in vitro and in vivo showed that loss of its deacetylase activity prevents OPC proliferation in hypoxia while promoting oligodendrocyte maturation – which underscores the importance of Sirt1 activity in maintaining the delicate balance between these two processes.

The tantalizing findings – the result of four years of research work in mouse models of neonatal hypoxia – hint at the prospect of lessening the severity of developmental delays experienced by the majority of preemies, Gallo adds. About 1 in 10 infants born in the United States are delivered preterm, prior to the 37th gestational week of pregnancy, according to the Centers for Disease Control and Prevention.  Brain injury associated with preterm birth – including white matter injury – can have long-term cognitive and behavioral consequences, with more than 50 percent of infants who survive prematurity needing special education, behavioral intervention and pharmacological treatment, Gallo says.

Time is of the essence, since Sirt1 plays a beneficial role at a certain place (white matter) and at a specific time (while the immature brain continues to develop). “We see maximal Sirt1 expression and activity within the first week after neonatal brain injury. There is a very narrow window in which to harness the stimulus that amplifies the progenitor cell population and target this particular molecule for repair,” he says.

Sirt1, a nicotinamide adenine dinucleotide-dependent class III histone deacetylase, is known to be involved in normal cell development, aging, inflammatory responses, energy metabolism and calorie restriction, the study team reports. Its activity can be modulated by sirtinol, an off-the-shelf drug that inhibits sirtuin proteins. The finding points to the potential for therapeutic interventions for diffuse white matter injury in neonates.

Next, the research team aims to study these processes in a large animal model whose brains are structurally, anatomically and metabolically similar to the human brain.

“Ideally, we want to be able to promote the timely regeneration of cells that are lost by designing strategies for interventions that synchronize these cellular events to a common and successful end,” Gallo says.