Universität zu Köln

Karlstetter, Marcus, Nothdurfter, Caroline, Aslanidis, Alexander, Moeller, Katharina, Horn, Felicitas, Scholz, Rebecca, Neumann, Harald ORCID: 0000-0002-5071-5202, Weber, Bernhard H. F., Rupprecht, Rainer and Langmann, Thomas (2014). Translocator protein (18 kDa) (TSPO) is expressed in reactive retinal microglia and modulates microglial inflammation and phagocytosis. J. Neuroinflamm., 11. LONDON: BIOMED CENTRAL LTD. ISSN 1742-2094

Full text not available from this repository.

Abstract

Background: The translocator protein (18 kDa) (TSPO) is a mitochondrial protein expressed on reactive glial cells and a biomarker for gliosis in the brain. TSPO ligands have been shown to reduce neuroinflammation in several mouse models of neurodegeneration. Here, we analyzed TSPO expression in mouse and human retinal microglia and studied the effects of the TSPO ligand XBD173 on microglial functions. Methods: TSPO protein analyses were performed in retinoschisin-deficient mouse retinas and human retinas. Lipopolysaccharide (LPS)-challenged BV-2 microglial cells were treated with XBD173 and TSPO shRNAs in vitro and pro-inflammatory markers were determined by qRT-PCR. The migration potential of microglia was determined with wound healing assays and the proliferation was studied with Fluorescence Activated Cell Sorting (FACS) analysis. Microglial neurotoxicity was estimated by nitrite measurement and quantification of caspase 3/7 levels in 661 W photoreceptors cultured in the presence of microglia-conditioned medium. The effects of XBD173 on filopodia formation and phagocytosis were analyzed in BV-2 cells and human induced pluripotent stem (iPS) cell-derived microglia (iPSdM). The morphology of microglia was quantified in mouse retinal explants treated with XBD173. Results: TSPO was strongly up-regulated in microglial cells of the dystrophic mouse retina and also co-localized with microglia in human retinas. Constitutive TSPO expression was high in the early postnatal Day 3 mouse retina and declined to low levels in the adult tissue. TSPO mRNA and protein were also strongly induced in LPS-challenged BV-2 microglia while the TSPO ligand XBD173 efficiently suppressed transcription of the pro-inflammatory marker genes chemokine (C-C motif) ligand 2 (CCL2), interleukin 6 (IL6) and inducible nitric oxide (NO)-synthase (iNOS). Moreover, treatment with XBD173 significantly reduced the migratory capacity and proliferation of microglia, their level of NO secretion and their neurotoxic activity on 661 W photoreceptor cells. Furthermore, XBD173 treatment of murine and human microglial cells promoted the formation of filopodia and increased their phagocytic capacity to ingest latex beads or photoreceptor debris. Finally, treatment with XBD173 reversed the amoeboid alerted phenotype of microglial cells in explanted organotypic mouse retinal cultures after challenge with LPS. Conclusions: These findings suggest that TSPO is highly expressed in reactive retinal microglia and a promising target to control microglial reactivity during retinal degeneration.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Karlstetter, Marcus UNSPECIFIED UNSPECIFIED UNSPECIFIED Nothdurfter, Caroline UNSPECIFIED UNSPECIFIED UNSPECIFIED Aslanidis, Alexander UNSPECIFIED UNSPECIFIED UNSPECIFIED Moeller, Katharina UNSPECIFIED UNSPECIFIED UNSPECIFIED Horn, Felicitas UNSPECIFIED UNSPECIFIED UNSPECIFIED Scholz, Rebecca UNSPECIFIED UNSPECIFIED UNSPECIFIED Neumann, Harald UNSPECIFIED orcid.org/0000-0002-5071-5202 UNSPECIFIED Weber, Bernhard H. F. UNSPECIFIED UNSPECIFIED UNSPECIFIED Rupprecht, Rainer UNSPECIFIED UNSPECIFIED UNSPECIFIED Langmann, Thomas UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-448669
DOI:	10.1186/1742-2094-11-3
Journal or Publication Title:	J. Neuroinflamm.
Volume:	11
Date:	2014
Publisher:	BIOMED CENTRAL LTD
Place of Publication:	LONDON
ISSN:	1742-2094
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language PERIPHERAL BENZODIAZEPINE-RECEPTOR; DIAZEPAM-BINDING INHIBITOR; INTRACELLULAR CALCIUM; THERAPEUTIC TARGET; LIGAND PK11195; MOUSE MODEL; BRAIN; ACTIVATION; SYSTEM; CELLS Multiple languages Immunology; Neurosciences Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/44866