Axl receptor tyrosine kinase is a regulator of apolipoprotein E

Alzheimer's disease (AD), the leading cause of dementia, is a chronic neurodegenerative disease. Apolipoprotein E (apoE), which carries lipids in the brain in the form of lipoproteins, plays an undisputed role in AD pathophysiology. A high-throughput phenotypic screen was conducted using a CCF-STTG1 human astrocytoma cell line to identify small molecules that could upregulate apoE secretion. AZ7235, a previously discovered Axl kinase inhibitor, was identified to have robust apoE activity in brain microglia, astrocytes and pericytes. AZ7235 also increased expression of ATP-binding cassette protein A1 (ABCA1), which is involved in the lipidation and secretion of apoE. Moreover, AZ7235 did not exhibit Liver-X-Receptor (LXR) activity and stimulated apoE and ABCA1 expression in the absence of LXR. Target validation studies using AXL-/- CCF-STTG1 cells showed that Axl is required to mediate AZ7235 upregulation of apoE and ABCA1. Intriguingly, apoE expression and secretion was significantly attenuated in AXL-deficient CCF-STTG1 cells and reconstitution of Axl or kinase-dead Axl significantly restored apoE baseline levels, demonstrating that Axl also plays a role in maintaining apoE homeostasis in astrocytes independent of its kinase activity. Lastly, these effects may require human apoE regulatory sequences, as AZ7235 exhibited little stimulatory activity toward apoE and ABCA1 in primary murine glia derived from neonatal human APOE3 targeted-replacement mice. Collectively, we identified a small molecule that exhibits robust apoE and ABCA1 activity independent of the LXR pathway in human cells and elucidated a novel relationship between Axl and apoE homeostasis in human astrocytes.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:13

Enthalten in:

Molecular brain - 13(2020), 1 vom: 04. Mai, Seite 66

Sprache:

Englisch

Beteiligte Personen:

Zhao, Wenchen [VerfasserIn]
Fan, Jianjia [VerfasserIn]
Kulic, Iva [VerfasserIn]
Koh, Cheryl [VerfasserIn]
Clark, Amanda [VerfasserIn]
Meuller, Johan [VerfasserIn]
Engkvist, Ola [VerfasserIn]
Barichievy, Samantha [VerfasserIn]
Raynoschek, Carina [VerfasserIn]
Hicks, Ryan [VerfasserIn]
Maresca, Marcello [VerfasserIn]
Wang, Qi [VerfasserIn]
Brown, Dean G [VerfasserIn]
Lok, Alvin [VerfasserIn]
Parro, Cameron [VerfasserIn]
Robert, Jerome [VerfasserIn]
Chou, Hsien-Ya [VerfasserIn]
Zuhl, Andrea M [VerfasserIn]
Wood, Michael W [VerfasserIn]
Brandon, Nicholas J [VerfasserIn]
Wellington, Cheryl L [VerfasserIn]

Links:

Volltext

Themen:

ABCA1 protein, human
ATP Binding Cassette Transporter 1
AXL
Alzheimer’s disease
Apolipoprotein E
Apolipoproteins E
Astrocyte
Axl Receptor Tyrosine Kinase
EC 2.7.10.1
Journal Article
Proto-Oncogene Proteins
Receptor Protein-Tyrosine Kinases
Research Support, Non-U.S. Gov't

Anmerkungen:

Date Completed 03.06.2021

Date Revised 07.12.2022

published: Electronic

Citation Status MEDLINE

doi:

10.1186/s13041-020-00609-1

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM309498406