Α7 nicotinic acetylcholine receptor signaling modulates ovine fetal brain astrocytes transcriptome in response to endotoxin

• Autores: Cao, Mingju; MacDonald, James W.; Liu, Hai L.; Weaver, Molly; Cortés Miguez, Marina; Durosier, Lucien D.; Burns, Patrick; Fecteau, Gilles; Desrochers, André; Schulkin, Jay; Antonelli, Marta Cristina; Bernier, Raphael A.; Dorschner, Michael; Bammler, Theo K.; Frasch, Martin Gerbert
• Año de publicación: 2019
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: ASTROCYTE; CHRNA7; FETAL PROGRAMMING; INFECTION; LPS; MICROGLIA; NEUROINFLAMMATION; RNASEQ
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Neuroinflammation in utero may result in lifelong neurological disabilities. Astrocytes play a pivotal role in this process, but the mechanisms are poorly understood. No early postnatal treatment strategies exist to enhance neuroprotective potential of astrocytes. We hypothesized that agonism on α7 nicotinic acetylcholine receptor (α7nAChR) in fetal astrocytes will augment their neuroprotective transcriptome profile, while the inhibition of α7nAChR will achieve the opposite. Using an in vivo-in vitro model of developmental programming of neuroinflammation induced by lipopolysaccharide (LPS), we validated this hypothesis in primary fetal sheep astrocytes cultures re-exposed to LPS in the presence of a selective α7nAChR agonist or antagonist. Our RNAseq findings show that a proinflammatory astrocyte transcriptome phenotype acquired in vitro by LPS stimulation is reversed with α7nAChR agonistic stimulation. Conversely, α7nAChR inhibition potentiates the pro-inflammatory astrocytic transcriptome phenotype. Furthermore, we conducted a secondary transcriptome analysis against the identical α7nAChR experiments in fetal sheep primary microglia cultures. Similar to findings in fetal microglia, in fetal astrocytes we observed a memory effect of in vivo exposure to inflammation, expressed in a perturbation of the iron homeostasis signaling pathway (hemoxygenase 1, HMOX1), which persisted under pre-treatment with α7nAChR antagonist but was reversed with α7nAChR agonist. For both glia cell types, common pathways activated due to LPS included neuroinflammation signaling and NF-κB signaling in some, but not all comparisons. However, overall, the overlap on the level of signaling pathways was rather minimal. Astrocytes, not microglia-the primary immune cells of the brain, were characterized by unique inhibition patterns of STAT3 pathway due to agonistic stimulation of α7nAChR prior to LPS exposure. Lastly, we discuss the implications of our findings for fetal and postnatal brain development.
Fil: Cao, Mingju. University of Montreal; Canadá
Fil: MacDonald, James W.. University of Washington; Estados Unidos
Fil: Liu, Hai L.. University of Montreal; Canadá
Fil: Weaver, Molly. University of Washington; Estados Unidos
Fil: Cortés Miguez, Marina. University of Montreal; Canadá
Fil: Durosier, Lucien D.. University of Montreal; Canadá
Fil: Burns, Patrick. University of Montreal; Canadá
Fil: Fecteau, Gilles. University of Montreal; Canadá
Fil: Desrochers, André. University of Montreal; Canadá
Fil: Schulkin, Jay. University of Washington; Estados Unidos
Fil: Antonelli, Marta Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina
Fil: Bernier, Raphael A.. University of Washington; Estados Unidos
Fil: Dorschner, Michael. University of Washington; Estados Unidos
Fil: Bammler, Theo K.. University of Washington; Estados Unidos
Fil: Frasch, Martin Gerbert. University of Montreal; Canadá. University of Washington; Estados Unidos