): This project seeks to identify the pathogenic actions of microglia and Th17 lymphocytes in infection-sensitized hypoxia-ischemia (HI) brain injury of newborns, including their interactions and strategies for intervention. The combination of prenatal infection and hypoxia-ischemia is a severe threat to immature brains, and often causes death or permanent neurological deficits. Better understanding the mechanisms of infection-sensitized neonatal HI injury is needed to design more effective therapies of this important neonatal disorder. Based on strong preliminary results, we hypothesize that the combination of systemic inflammatory responses and HI promotes early onset of Th17 cells in neonatal brains. The Th17 cell cytokines and tPA (tissue plasminogen activator)-mediated sensitization of endotoxin signaling greatly enhances microglial activation, which not only causes severe brain injury but also fosters the maturation of Th17 cells. We will test this hypothesis in two specific aims.
Aim 1 addresses the unique responses of microglia/monocytes to infection-HI and their effects on Th17 cell maturation.
Aim 2 addresses the functions Th17 cells in infection-HI and their effects on microglia and monocyte activation in this condition. In sum, this project will determine the mechanisms of microglia-Th17 cell crosstalk in neonatal infection/HI brain injury, and provide the scientific basis for potential new therapies.
): Intrauterine infection (chorioamnionitis) is a major risk factor for cerebral palsy in both term and preterm neonates. Clinical and animal studies showed that the combination of HI and systemic inflammation cauces greater brain damage and poorer responses to therapeutic hypothermia. A recent workshop at the NICHD cautioned, ?cooling in the presence of infection may be deleterious?. Hence, it is important to better understand the unique pathogenesis of infection- sensitized HI brain injury in order to devise more successful therapies.
|Sun, Yu-Yo; Lee, Jolly; Huang, Henry et al. (2017) Sickle Mice Are Sensitive to Hypoxia/Ischemia-Induced Stroke but Respond to Tissue-Type Plasminogen Activator Treatment. Stroke 48:3347-3355|
|Li, Yikun; Dammer, Eric B; Zhang-Brotzge, Xiaohui et al. (2017) Osteopontin Is a Blood Biomarker for Microglial Activation and Brain Injury in Experimental Hypoxic-Ischemic Encephalopathy. eNeuro 4:|