Cerebroprotective Effect of 17beta-Estradiol Replacement Therapy in Ovariectomy-Induced Post-Menopausal Rats Subjected to Ischemic Stroke: Role of MAPK/ERK1/2 Pathway and PI3K-Independent Akt Activation.

Fecha de publicación: 19/09/2023 Fecha Ahead of Print: 19/09/2023

Autores de IIS La Fe

• María Consuelo Burguete López

  Autor

• María Castelló Ruiz

  Autor

• Alicia Aliena Valero

  Autor

• Enrique Alborch Domínguez

  Autor

• Germán Torregrosa Bernabé

  Autor

Participantes ajenos a IIS La Fe

• Jover-Mengual, Teresa
• Lopez-Morales, Mikahela A.
• Centeno, Jose M.
• Salom, Juan B.

Grupos

• Unidad Mixta de Investigación Cerebrovascular

  Leader

  Juan Bautista Salom Sanvalero

Abstract

Despite the overwhelming advances in the understanding of the pathogenesis of stroke, a devastating disease affecting millions of people worldwide, currently there are only a limited number of effective treatments available. Preclinical and clinical studies show that stroke is a sexually dimorphic disorder, affecting males and females differently. Strong experimental evidence indicates that estrogen may play a role in this difference and that exogenous 17beta-estradiol (E2) is neuroprotective against stroke in both male and female rodents. However, the molecular mechanisms by which E2 intervenes in ischemia-induced cell death, revealing these sex differences, remain unclear. The present study was aimed to determine, in female rats, the molecular mechanisms of two well-known pro-survival signaling pathways, MAPK/ERK1/2 and PI3K/Akt, that mediate E2 neuroprotection in response to acute ischemic stroke. E2 pretreatment reduced brain damage and attenuated apoptotic cell death in ovariectomized female rats after an ischemic insult. Moreover, E2 decreased phosphorylation of ERK1/2 and prevented ischemia/reperfusion-induced dephosphorylation of both Akt and the pro-apoptotic protein, BAD. However, MAPK/ERK1/2 inhibitor PD98059, but not the PI3K inhibitor LY294002, attenuated E2 neuroprotection. Thus, these results suggested that E2 pretreatment in ovariectomized female rats modulates MAPK/ERK1/2 and activates Akt independently of PI3K to promote cerebroprotection in ischemic stroke. A better understanding of the mechanisms and the influence of E2 in the female sex paves the way for the design of future successful hormone replacement therapies.

Keywords

• 17ß-estradiol; MAPK/ERK; PI3K/Akt; apoptosis; ischemic stroke; neuronal death; neuroprotection