Kristen R Hollinger1,2,3, Xiaolei Zhu1,3, Elizabeth S Khoury4, Ajit G Thomas3, Kevin Liaw5, Carolyn Tallon2,3, Ying Wu3, Eva Prchalova2,3, Atsushi Kamiya1, Camilo Rojas2,3, Sujatha Kannan4, Barbara S Slusher1,2,3,6,7,8,9. 1. Departments of Psychiatry and Behavioral Sciences, Johns Hopkins University, Baltimore, MD, USA. 2. Departments of Neurology, Johns Hopkins University, Baltimore, MD, USA. 3. Departments of Johns Hopkins Drug Discovery, Johns Hopkins University, Baltimore, MD, USA. 4. Departments of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA. 5. Departments of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA. 6. Departments of Pharmacology and Molecular Sciences, Johns Hopkins University, Baltimore, MD, USA. 7. Departments of Neuroscience, Johns Hopkins University, Baltimore, MD, USA. 8. Departments of Medicine, Johns Hopkins University, Baltimore, MD, USA. 9. Departments of Oncology, and Johns Hopkins University, Baltimore, MD, USA.
Abstract
BACKGROUND: Given the emergent aging population, the identification of effective treatments for Alzheimer's disease (AD) is critical. OBJECTIVE: We investigated the therapeutic efficacy of JHU-083, a brain-penetrable glutamine antagonist, in treating AD using the humanized APOE4 knock-in mouse model. METHODS: Cell culture studies were performed using BV2 cells and primary microglia isolated from hippocampi of adult APOE4 knock-in mice to evaluate the effect of JHU-083 treatment on LPS-induced glutaminase (GLS) activity and inflammatory markers. Six-month-old APOE4 knock-in mice were administered JHU-083 or vehicle via oral gavage 3x/week for 4-5 months and cognitive performance was assessed using the Barnes maze. Target engagement in the brain was confirmed using a radiolabeled GLS enzymatic activity assay, and electrophysiology, gastrointestinal histology, blood chemistry, and CBC analyses were conducted to evaluate the tolerability of JHU-083. RESULTS: JHU-083 inhibited the LPS-mediated increases in GLS activity, nitic oxide release, and pro-inflammatory cytokine production in cultured BV2 cells and primary microglia isolated from APOE4 knock-in AD mice. Chronic treatment with JHU-083 in APOE4 mice improved hippocampal-dependent Barnes maze performance. Consistent with the cell culture findings,postmortem analyses of APOE4 mice showed increased GLS activity in hippocampal CD11b+ enriched cells versus age-matched controls, which was completely normalized by JHU-083 treatment. JHU-083 was well-tolerated, showing no weight loss effect or overt behavioral changes. Peripheral nerve function, gastrointestinal histopathology, and CBC/clinical chemistry parameters were all unaffected by chronic JHU-083 treatment. CONCLUSION: These results suggest that the attenuation of upregulated hippocampal glutaminase by JHU-083 represents a new therapeutic strategy for AD.
BACKGROUND: Given the emergent aging population, the identification of effective treatments for Alzheimer's disease (AD) is critical. OBJECTIVE: We investigated the therapeutic efficacy of JHU-083, a brain-penetrable glutamine antagonist, in treating AD using the humanized APOE4 knock-in mouse model. METHODS: Cell culture studies were performed using BV2 cells and primary microglia isolated from hippocampi of adult APOE4 knock-in mice to evaluate the effect of JHU-083 treatment on LPS-induced glutaminase (GLS) activity and inflammatory markers. Six-month-old APOE4 knock-in mice were administered JHU-083 or vehicle via oral gavage 3x/week for 4-5 months and cognitive performance was assessed using the Barnes maze. Target engagement in the brain was confirmed using a radiolabeled GLS enzymatic activity assay, and electrophysiology, gastrointestinal histology, blood chemistry, and CBC analyses were conducted to evaluate the tolerability of JHU-083. RESULTS: JHU-083 inhibited the LPS-mediated increases in GLS activity, nitic oxide release, and pro-inflammatory cytokine production in cultured BV2 cells and primary microglia isolated from APOE4 knock-in AD mice. Chronic treatment with JHU-083 in APOE4 mice improved hippocampal-dependent Barnes maze performance. Consistent with the cell culture findings,postmortem analyses of APOE4 mice showed increased GLS activity in hippocampal CD11b+ enriched cells versus age-matched controls, which was completely normalized by JHU-083 treatment. JHU-083 was well-tolerated, showing no weight loss effect or overt behavioral changes. Peripheral nerve function, gastrointestinal histopathology, and CBC/clinical chemistry parameters were all unaffected by chronic JHU-083 treatment. CONCLUSION: These results suggest that the attenuation of upregulated hippocampal glutaminase by JHU-083 represents a new therapeutic strategy for AD.
Authors: Ajit G Thomas; Cliona M O'Driscoll; Joseph Bressler; Walter Kaufmann; Camilo J Rojas; Barbara S Slusher Journal: Biochem Biophys Res Commun Date: 2013-11-19 Impact factor: 3.575