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An-Massaro

How EPO saves babies’ brains

An-Massaro

“These findings suggest that EPO’s neuroprotective effect may be mediated by epigenetic regulation of genes involved in the development of the nervous system and that play pivotal roles in how the body responds to inflammation and hypoxia,” says An Massaro, M.D.

The drug erythropoietin (EPO) has a long history. First used more than three decades ago to treat anemia, it’s now a mainstay for treating several types of this blood-depleting disorder, including anemia caused by chronic kidney disease, myelodysplasia and cancer chemotherapy.

More recently, researchers discovered a new use for this old drug: Treating premature infants to protect and repair their vulnerable brains. However, how EPO accomplishes this feat has remained unknown. New genetic analyses presented at the Pediatric Academic Societies 2018 annual meeting that was conducted by a multi-institutional team that includes researchers from Children’s National show that this drug may work its neuroprotective magic by modifying genes essential for regulating growth and development of nervous tissue as well as genes that respond to inflammation and hypoxia.

“During the last trimester of pregnancy, the fetal brain undergoes tremendous growth. When infants are born weeks before their due dates, these newborns’ developing brains are vulnerable to many potential insults as they are supported in the neonatal intensive care unit during this critical time,” says An Massaro, M.D., an attending neonatologist at Children’s National Health System and lead author of the research. “EPO, a cytokine that protects and repairs neurons, is a very promising therapeutic approach to support the developing brains of extremely low gestational age neonates.”

The research team investigated whether micro-preemies treated with EPO had distinct DNA methylation profiles and related changes in expression of genes that regulate how the body responds to such environmental stressors as inflammation, hypoxia and oxidative stress.  They also investigated changes in genes involved in glial differentiation and myelination, production of an insulating layer essential for a properly functioning nervous system. The genetic analyses are an offshoot of a large, randomized clinical trial of EPO to treat preterm infants born between 24 and 27 gestational weeks.

The DNA of 18 newborns enrolled in the clinical trial was isolated from specimens drawn within 24 hours of birth and at day 14 of life. Eleven newborns were treated with EPO; a seven-infant control group received placebo.

DNA methylation and whole transcriptome analyses identified 240 candidate differentially methylated regions and more than 50 associated genes that were expressed differentially in infants treated with EPO compared with the control group. Gene ontology testing further narrowed the list to five candidate genes that are essential for normal neurodevelopment and for repairing brain injury:

“These findings suggest that EPO’s neuroprotective effect may be mediated by epigenetic regulation of genes involved in the development of the nervous system and that play pivotal roles in how the body responds to inflammation and hypoxia,” Dr. Massaro says.

In addition to Dr. Massaro, study co-authors include Theo K. Bammler, James W. MacDonald, biostatistician, Bryan Comstock, senior research scientist, and Sandra “Sunny” Juul, M.D., Ph.D., study principal investigator, all of University of Washington.

Breastfeeding Mom

Breast milk helps white matter in preemies

Breastfeeding Mom

Critical white matter structures in the brains of babies born prematurely at low birth weight develop more robustly when their mothers breast-feed them, compared with preemies fed formula.

Breast-feeding offers a slew of benefits to infants, including protection against common childhood infections and potentially reducing the risk of chronic health conditions such as asthma, obesity and type 2 diabetes. These benefits are especially important for infants born prematurely, or before 37 weeks gestation – a condition that affects 1 in 10 babies born in the United States, according to the Centers for Disease Control and Prevention. Prematurely born infants are particularly vulnerable to infections and other health problems.

Along with the challenges premature infants face, there is a heightened risk for neurodevelopmental disabilities that often do not fully emerge until the children enter school. A new study by Children’s National Health System researchers shows that breast-feeding might help with this problem. The findings, presented at the 2017 annual meeting of the Pediatric Academic Societies, show that critical white matter structures in the brains of babies born so early that they weigh less than 1,500 grams develop more robustly when their mothers breast-feed them, compared with preemie peers who are fed formula.

The Children’s National research team used sophisticated imaging tools to examine brain development in very low birth weight preemies, who weighed about 3 pounds at birth.

They enrolled 37 babies who were no more than 32 weeks gestational age at birth and were admitted to Children’s neonatal intensive care unit within the first 48 hours of life. Twenty-two of the preemies received formula specifically designed to meet the nutritional needs of infants born preterm, while 15 infants were fed breast milk. The researchers leveraged diffusion tensor imaging – which measures organization of the developing white matter of the brain – and 3-D volumetric magnetic resonance imaging (MRI) to calculate brain volume by region, structure and tissue type, such as cortical gray matter, white matter, deep gray matter and cerebellum.

“We did not find significant differences in the global and regional brain volumes when we conducted MRIs at 40 weeks gestation in both groups of prematurely born infants,” says Catherine Limperopoulos, Ph.D., director of the Developing Brain Research Laboratory and senior author of the paper. “There are striking differences in white matter microstructural organization, however, with greater fractional anisotropy in the left posterior limb of internal capsule and middle cerebellar peduncle, and lower mean diffusivity in the superior cerebellar peduncle.”

White matter lies under the gray matter cortex, makes up about half of the brain’s volume, and is a critical player in human development as well as in neurological disorders. The increased white matter microstructural organization in the cerebral and cerebellar white matter suggests more robust fiber tracts and microarchitecture of the developing white matter which may predict better neurologic outcomes in preterm infants. These critical structures that begin to form in the womb are used for the rest of the person’s life when, for instance, they attempt to master a new skill.

“Previous research has linked early breast milk feeding with increased volumetric brain growth and improved cognitive and behavioral outcomes,” she says. “These very vulnerable preemies already experience a high incidence rate of neurocognitive dysfunction – even if they do not have detectable structural brain injury. Providing them with breast milk early in life holds the potential to lessen those risks.”

The American Academy of Pediatrics endorses breast-feeding because it lowers infants’ chances of suffering from ear infections and diarrhea in the near term and decreases their risks of being obese as children. Limperopoulos says additional studies are needed in a larger group of patients as well as longer-term follow up as growing infants babble, scamper and color to gauge whether there are differences in motor skills, cognition and writing ability between the two groups.