Glucocorticoid Receptor β Isoform Predominates in the Human Dysplastic Brain Region and Is Modulated by Age, Sex, and Antiseizure Medication
Abstract number :
1.039
Submission category :
1. Basic Mechanisms / 1D. Mechanisms of Therapeutic Interventions
Year :
2022
Submission ID :
2203967
Source :
www.aesnet.org
Presentation date :
12/3/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:22 AM
Authors :
Chaitali Ghosh, PhD – Cleveland Clinic Lerner Research Institute; Rosemary Westcott, BS – Biomedical Engineering – Cleveland Clinic Lerner Research Institute; Natalie Chung, BS – Biomedical Engineering – Cleveland Clinic Lerner Research Institute; Arnab Ghosh, PhD – Inflammation and Immunity – Cleveland Clinic Lerner Research Institute; Lisa Ferguson, BS – Charles Shor Epilepsy Center – Cleveland Clinic Neurological Institute; William Bingaman, MD – Charles Shor Epilepsy Center – Cleveland Clinic Neurological Institute; Imad Najm, MD – Charles Shor Epilepsy Center – Cleveland Clinic Neurological Institute
Rationale: The glucocorticoid receptor (GR) at the blood–brain barrier (BBB) is involved in the pathogenesis of drug-resistant epilepsy with focal cortical dysplasia (FCD); however, the roles of GR isoforms GRα and GRβ in the dysplastic brain have not been revealed. _x000D_
Methods: We utilized brain tissue from the dysplastic/epileptic and non-dysplastic regions of patients who underwent resective epilepsy surgery to identify the GRα and GRβ levels, subcellular localization and cellular specificity. The BBB endothelial cells isolated from the dysplastic brain tissue (EPI-ECs) were used to decipher the key BBB proteins related to drug regulation (GRα; GRβ; heat shock protein/Hsp90; drug efflux transporter/ Pgp; cytochrome P450 drug metabolizing enzymes/ CYP3A4, CYP2C9). The pattern in EPI-ECs was compared to control BBB endothelial cells and transfected GRβ-overexpressed endothelial cells. Regulators of BBB integrity, including tight junction proteins and the pro-/active-forms of matrix metalloproteinase (MMP)-9 and MMP activity were evaluated.
Results: GRβ was found upregulated in dysplastic compared to non-dysplastic brain tissues, and an imbalance of the GRα/GRβ ratio was significant in females vs. males and in patients more than 45 years old. Subcellular localization in dysplastic and non-dysplastic tissues from patients grouped by their antiseizure medication, ASM regimen (a combination of CYP-mediated ASMs or CYP- and non-CYP-mediated ASMs) showed that GRβ was heavily located in the nuclear fraction of the dysplastic tissue of the CYP+ CYP-mediated ASM group, which was not seen in the CYP+ non-CYP-mediated ASM group. In EPI-ECs, the subcellular localization and expression patterns of GRβ, Hsp90, CYP3A4, and CYP2C9 were consistent with GRβ+ brain endothelial cells. Active MMP levels and activity were increased, whereas claudin-5 levels decreased in both EPI-ECs and GRβ+ brain endothelial cells.
Conclusions: In summary, the study revealed that GRβ has a major effect on dysplastic BBB functional proteins and is age and gender-dependent, suggesting a critical role of brain GRβ isoform in dysplasia as a potential biomarker and therapeutic target in epilepsy.
Funding: This work is supported in part by the National Institute of Neurological Disorders and Stroke/National Institutes of Health grant R01NS095825 awarded to Dr. Chaitali Ghosh.
Basic Mechanisms