| First Author | Cikla U | Year | 2016 |
| Journal | eNeuro | Volume | 3 |
| Issue | 1 | PubMed ID | 26839918 |
| Mgi Jnum | J:240079 | Mgi Id | MGI:5882295 |
| Doi | 10.1523/ENEURO.0025-15.2015 | Citation | Cikla U, et al. (2016) ERalpha Signaling Is Required for TrkB-Mediated Hippocampal Neuroprotection in Female Neonatal Mice after Hypoxic Ischemic Encephalopathy(1,2,3). eNeuro 3(1):ENEURO.0025-15.2015 |
| abstractText | Male neonate brains are more susceptible to the effects of perinatal asphyxia resulting in hypoxia and ischemia (HI)-related brain injury. The relative resistance of female neonatal brains to adverse consequences of HI suggests that there are sex-specific mechanisms that afford females greater neuroprotection and/or facilitates recovery post-HI. We hypothesized that HI preferentially induces estrogen receptor alpha (ERalpha) expression in female neonatal hippocampi and that ERalpha is coupled to Src family kinase (SFK) activation that in turn augments phosphorylation of the TrkB and thereby results in decreased apoptosis. After inducing the Vannucci's HI model on P9 (C57BL/6J) mice, female and male ERalpha wild-type (ERalpha(+/+)) or ERalpha null mutant (ERalpha(-/-)) mice received vehicle control or the selective TrkB agonist 7,8-dihydroxyflavone (7,8-DHF). Hippocampi were collected for analysis of mRNA of ERalpha and BDNF, protein levels of ERalpha, p-TrkB, p-src, and cleaved caspase 3 (c-caspase-3) post-HI. Our results demonstrate that: (1) HI differentially induces ERalpha expression in the hippocampus of the female versus male neonate, (2) src and TrkB phosphorylation post-HI is greater in females than in males after 7,8-DHF therapy, (3) src and TrkB phosphorylation post-HI depend on the presence of ERalpha, and (4) TrkB agonist therapy decreases the c-caspase-3 only in ERalpha(+/+) female mice hippocampus. Together, these observations provide evidence that female-specific induction of ERalpha expression confers neuroprotection with TrkB agonist therapy via SFK activation and account for improved functional outcomes in female neonates post-HI. |
