Adult and neonatal astrocytes exhibit diverse gene expression profiles during exposure to beta amyloid ex vivo

Research regarding the role of astrocytes as -amyloid (A) degrading cells has broadened our view about the mechanisms how these common glia cells function in Alzheimers disease (AD). Based on previous studies adult mouse astrocytes are able to degrade A deposits from AD mouse model and human brain tissue sections ex vivo, contrary to neonatal astrocytes. In this study, we studied the possible altered gene expression profiles of adult and neonatal astrocytes cultured for 22 h on top of the A burdened tg APdE9 or wild-type mouse brain sections using whole genome microarrays. Quantitative RT-PCR analysis confirmed the significant up-regulation of HtrA serine peptidase 1 (Htra1), metallopeptidase 9 (Mmp9), phosphate regulating gene with homologies to endopeptidases on the X chromosome (Phex) and scavenger receptor class A, member 5 (Scara5) in adult astrocytes, whereas neonatal astrocytes up-regulated Mmp9 and down-regulated genes related to cholesterol transport and synthesis: apolipoprotein E (Apoe), 24-dehydrocholesterol reductase (Dhcr24) and 3-hydroxy-3-methylglutaryl-CoA synthase 1 (Hmgcs1). These findings brought out novel genes which expression is altered during A clearance in adult and neonatal astrocytes ex vivo.

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