4.6 Article

Development and Characterization of Inducible Astrocyte-Specific Aromatase Knockout Mice

Journal

BIOLOGY-BASEL
Volume 12, Issue 4, Pages -

Publisher

MDPI
DOI: 10.3390/biology12040621

Keywords

estradiol; neuroestrogen; neurosteroid; aromatase; cerebral ischemia; astrocyte; microglia

Categories

Ask authors/readers for more resources

Recent research has found that the steroid hormone 17 beta-estradiol (E-2) is produced in the brain by both neurons and astrocytes. A new inducible knockout mouse model was created to specifically deplete the E-2 in astrocytes of adult mice, providing a better research model for studying brain-derived E-2 and its functions. The characterization of this mouse model confirmed the specific depletion of aromatase and E-2 in astrocytes, and revealed the neuroprotective role of astrocyte-derived E-2 in cerebral ischemia.
Simple Summary Recent work has shown that the steroid hormone17 beta-estradiol (E-2) is also produced in the brain in both neurons and astrocytes. The current animal models for depleting E-2, specifically in astrocytes, are non-inducible, which can provide a developmental confound. It would be advantageous to have an inducible knockout model where the E-2 depletion in astrocytes could be performed in adult animals, so as to avoid this confound. Thus, in the current study, we created an inducible knockout mouse model to deplete the E-2 specifically in the astrocytes of adult mice. The characterization of the inducible knockout mice confirmed that aromatase and E-2 were depleted specifically in the astrocytes of the adult mice. The study further revealed that astrocyte-derived E-2 had a significant role in protecting the brain from cerebral ischemia (stroke) and regulated both the astrocyte and microglia activation after a cerebral ischemia. 17 beta-estradiol (E2) is produced in the brain as a neurosteroid, in addition to being an endocrine signal in the periphery. The current animal models for studying brain-derived E-2 include global and conditional non-inducible knockout mouse models. The aim of this study was to develop a tamoxifen (TMX)-inducible astrocyte-specific aromatase knockout mouse line (GFAP-ARO-iKO mice) to specifically deplete the E-2 synthesis enzymes and aromatase in astrocytes after their development in adult mice. The characterization of the GFAP-ARO-iKO mice revealed a specific and robust depletion in the aromatase expressions of their astrocytes and a significant decrease in their hippocampal E-2 levels after a GCI. The GFAP-ARO-iKO animals were alive and fertile and had a normal general brain anatomy, with a normal astrocyte shape, intensity, and distribution. In the hippocampus, after a GCI, the GFAP-ARO-iKO animals showed a major deficiency in their reactive astrogliosis, a dramatically increased neuronal loss, and increased microglial activation. These findings indicate that astrocyte-derived E-2 (ADE(2)) regulates the ischemic induction of reactive astrogliosis and microglial activation and is neuroprotective in the ischemic brain. The GFAP-ARO-iKO mouse models thus provide an important new model to help elucidate the roles and functions of ADE(2) in the brain.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.6
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available