The Impact of the Timing of Dosing on the Severity of UNC569-Induced Ultrastructural Changes in the Mouse Retina

Mer proto-oncogene tyrosine kinase (MerTK), expressed in the retinal pigment epithelium (RPE), regulates the phagocytosis of shed photoreceptor outer segments. To investigate the influence of dosing time on MerTK inhibitor UNC569-induced retinal toxicity, UNC569 at 100 mg/kg was orally administered to male mice at 2 different Zeitgeber times (ZT5.5 or ZT22) for 28 days. Electron microscopy was conducted at ZT2 after the final dosing. Additionally, the visual cycle components (11-cis-retinal, all-trans-retinal, all-trans-retinol, and 11-cis-retinol), which play an important role in maintaining retinal homeostasis, were quantified by liquid chromatography/mass spectrometry/mass spectrometry. Under electron microscopic examination, the number of phagosomes and phagolysosomes in the RPE increased in both the ZT5.5 and ZT22 administered groups, while endoplasmic reticulum dilatation in the RPE and chromatin aggregation of photoreceptor nuclei were observed only in the ZT22 administered group. No change was observed in any of the visual cycle components. These results suggest that the timing of the dosing in relation to the physiological MerTK phosphorylation affected the severity of changes in the RPE, leading to the apoptosis of the photoreceptor cells.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:48

Enthalten in:

Toxicologic pathology - 48(2020), 5 vom: 04. Juli, Seite 669-676

Sprache:

Englisch

Beteiligte Personen:

Sayama, Ayako [VerfasserIn]
Okado, Keiko [VerfasserIn]
Yamaguchi, Mayu [VerfasserIn]
Samata, Naozumi [VerfasserIn]
Imaoka, Masako [VerfasserIn]
Kai, Kiyonori [VerfasserIn]
Mori, Kazuhiko [VerfasserIn]

Links:

Volltext

Themen:

C-Mer Tyrosine Kinase
Chronotoxicity
EC 2.7.10.1
Journal Article
MerTK
Phagocytosis
Photoreceptor cells
Pyrazoles
Pyrimidines
Receptor Protein-Tyrosine Kinases
Retina
Retinal pigment epithelium
UNC569
Visual cycle

Anmerkungen:

Date Completed 26.05.2021

Date Revised 26.05.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1177/0192623320931415

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM311173977