Exendin-4 improves neurodevelopmental outcome after neonatal germinal matrix hemorrhage

Germinal matrix hemorrhage (GMH) is a common complication in premature infants and is associated with a high risk of neurodevelopmental impairment and mortality. Currently, there are no specific neuroprotective treatments available. Exendin-4 is a drug used for the treatment of type 2 diabetes mellitus, and it has shown neuroprotective effects in several neurological disorders including Alzheimer's and Parkinson's disease. In this study, we used the preterm postnatal day 5 rat model of GMH to evaluate whether exendin-4 exerts neuroprotective effects in this setting. Our results show that in the acute phase, exendin-4 reduced microglial activation, caspase-3 activation, p53 expression, AIF-associated cell death, MMP-9 expression, and neutrophil infiltration into the hemorrhage site. Exendin-4 treatment improved neurodevelopmental outcomes in both negative geotaxis and eye-opening latency when compared to saline-treated GMH controls, and conferred gray and white matter protection as early as 48 h after injury, with persistent neuroprotection observed at 5, 11, and 35 days after GMH. Exendin-4-treated animals also showed significant recovery of motor function in the rotarod test. In summary, this study demonstrates that exendin-4 reduces brain injury in a rat model of GMH in both the short and long term and is associated with improved neurological outcome.