TO901317 activation of LXR-dependent pathways mitigate amyloid-beta peptide-induced neurotoxicity in 3D human neural stem cell culture scaffolds and AD mice

Ming-Chang Chiang; Christopher J B Nicol; Shiang-Jiuun Chen; Rong-Nan Huang

doi:10.1016/j.brainresbull.2021.11.004

TO901317 activation of LXR-dependent pathways mitigate amyloid-beta peptide-induced neurotoxicity in 3D human neural stem cell culture scaffolds and AD mice

Brain Res Bull. 2022 Jan:178:57-68. doi: 10.1016/j.brainresbull.2021.11.004. Epub 2021 Nov 18.

Authors

Ming-Chang Chiang¹, Christopher J B Nicol², Shiang-Jiuun Chen³, Rong-Nan Huang⁴

Affiliations

¹ Department of Life Science, College of Science and Engineering, Fu Jen Catholic University, New Taipei City 242, Taiwan. Electronic address: 089034@mail.fju.edu.tw.
² Departments of Pathology & Molecular Medicine and Biomedical & Molecular Sciences, and Cancer Biology and Genetics Division, Cancer Research Institute, Queen's University, Kingston, ON K7L 3N6, Canada.
³ Department of Life Science and Institute of Ecology and Evolutionary Biology, College of Life Science, National Taiwan University, Taipei 106, Taiwan.
⁴ Department of Entomology and Research Center for Plant-Medicine, National Taiwan University, Taipei 106, Taiwan.

PMID: 34801648
DOI: 10.1016/j.brainresbull.2021.11.004

Abstract

Alzheimer's disease (AD) is the major cause of neurodegeneration worldwide and is characterized by the accumulation of amyloid beta (Aβ) in the brain, which is associated with neuronal loss and cognitive impairment. Liver X receptor (LXR), a critical nuclear receptor, and major regulator in lipid metabolism and inflammation, is suggested to play a protective role against the mitochondrial dysfunction noted in AD. In our study, our established 3D gelatin scaffold model and a well characterized in vivo (APP/PS1) murine model of AD were used to directly investigate the molecular, biochemical and behavioral effects of neuronal stem cell exposure to Aβ to improve understanding of the in vivo etiology of AD. Herein, human neural stem cells (hNSCs) in our 3D model were exposed to Aβ, and had significantly decreased cell viability, which correlated with decreased mRNA and protein expression of LXR, Bcl-2, CREB, PGC1α, NRF-1, and Tfam, and increased caspase 3 and 9 activities. Cotreatment with a synthetic agonist of LXR (TO901317) significantly abrogated these Aβ-mediated effects in hNSCs. Moreover, TO901317 cotreatment both significantly rescues hNSCs from Aβ-mediated decreases in ATP levels and mitochondrial mass, and significantly restores Aβ-induced fragmented mitochondria to almost normal morphology. TO901317 cotreatment also decreases tau aggregates in Aβ-treated hNSCs. Importantly, TO901317 treatment significantly alleviates the impairment of memory, decreases Aβ aggregates and increases proteasome activity in APP/PS1 mice; whereas, these effects were blocked by cotreatment with an LXR antagonist (GSK2033). Together, these novel results improve our mechanistic understanding of the central role of LXR in Aβ-mediated hNSC dysfunction. We also provide preclinical data unveiling the protective effects of using an LXR-dependent agonist, TO901317, to block the toxicity observed in Aβ-exposed hNSCs, which may guide future treatment strategies to slow or prevent neurodegeneration in some AD patients.

Keywords: AD mice; Aβ; HNSCs; LXR; Mitochondrial function; TO901317.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Alzheimer Disease / drug therapy*
Amyloid beta-Peptides / pharmacology*
Animals
Cells, Cultured
Disease Models, Animal
Humans
Liver X Receptors / agonists*
Memory Disorders / drug therapy*
Mice
Mitochondrial Diseases / drug therapy*
Neural Stem Cells / drug effects*
Neuroprotective Agents / pharmacology*

Substances

Amyloid beta-Peptides
Liver X Receptors
Neuroprotective Agents