Journal Article FZJ-2026-04879

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png
Microglia derived from human induced pluripotent stem cells are regulated by osteopontin, an endogenous extracellular matrix protein maintaining immune homeostasis

 ;  ;  ;  ;  ;  ;  ;  ;

2026
Frontiers Research Foundation Lausanne

Frontiers in neuroscience 20, 1785992 () [10.3389/fnins.2026.1785992]

This record in other databases:  

Please use a persistent id in citations: doi:  doi:

Abstract: Introduction: Microglia are brain-resident immune cells responsible for maintaining homeostasis, coordinating responses to injury and disease, and mediating regeneration. Upon activation, they undergo dynamic changes in morphology, gene expression, and function, reflecting the nature and context of the stimuli encountered. Although pharmacological modulation of microglia holds great promise for treating various neurological disorders, its development is hampered by a major translational roadblock: Human microglial cell lines commonly used in preclinical studies, as well as primary rodent microglia, substantially limit the translatability of results. Here, we aimed to generate microglia from human induced pluripotent stem cells (hiPSCs) and to demonstrate their physiological responsiveness to the brain-endogenous, context-relevant ligand osteopontin (OPN).Materials and methods: Microglia generated from two healthy hiPSC lines were stimulated with OPN, lipopolysaccharide (LPS), or their combination for 24 h and subsequently analyzed. Microglial identity and the expression of the phagocytic cell marker cluster of differentiation 68 (CD68) were determined by immunocytochemistry. Cell viability was assessed by propidium iodide (PI)/Hoechst staining, morphological activation was evaluated using Sholl analysis, and inflammatory gene expression changes were assessed by RT-qPCR.Results: hiPSC-derived microglia acquired a native central nervous system (CNS)-specific immunophenotype, expressing the microglia-specific markers ionized calcium-binding adapter molecule 1 (IBA1), transmembrane protein 119 (TMEM119), PU.1, and Spalt-like transcription factor 1 (SALL1), while remaining negative for Myb and membrane-spanning 4-domains, subfamily A, member 7 (MS4A7) at the protein level. Exposure to LPS led hiPSC-derived microglia to adopt a rounded, process-retracted shape and to increase CD68 protein intensity, a surrogate marker of lysosomal and phagocytic activity, while downregulating the anti-inflammatory marker cluster of differentiation 206 (CD206) at the transcriptional level. OPN induced a distinct microglial functional state characterized by intermediate morphology, increased CD68 intensity, and reduced homeostatic gene expression, without eliciting robust inflammatory gene expression. Intriguingly, OPN prevented LPS-induced microglial cell death, and when hiPSC-derived microglia exposed to LPS were additionally treated with OPN, the morphological effects of LPS were reversed.Conclusion: OPN induced a distinct early response profile in hiPSC-derived microglia, characterized by intermediate morphological remodeling, increased CD68 intensity, and reduced homeostatic gene expression, without overt pro-inflammatory gene expression. These findings support the role of OPN as a physiological priming signal in microglia and highlight hiPSC-derived microglia as a model for studying regulators of microglial modulation.Keywords: iPSC (induced pluripotent stem cell); in vitro model culture system; microglia; neuroinflammation; osteopontin.

Classification:

Note: The author(s) declared that financial support was received for this work and/or its publication. The project was funded by the Deutsche Forschungsgemeinscha (DFG, German Research Founda on; Project-ID 431549029-SFB 1451) and by the Marga-und-Walter-Boll-S (#210-10-15). AMK was supported by the “Köln Fortune Program” Faculty of Medicine, University of Cologne, Germany

Contributing Institute(s):
  1. Kognitive Neurowissenschaften (INM-3)
Research Program(s):
  1. 5251 - Multilevel Brain Organization and Variability (POF4-525) (POF4-525)
  2. DFG project G:(GEPRIS)431549029 - SFB 1451 Schlüsselmechanismen normaler und krankheitsbedingt gestörter motorischer Kontrolle (431549029) (431549029)

Appears in the scientific report 2026
Database coverage:
Medline ; Creative Commons Attribution CC BY 4.0 ; DOAJ ; OpenAccess ; Article Processing Charges ; BIOSIS Previews ; Biological Abstracts ; Clarivate Analytics Master Journal List ; Current Contents - Clinical Medicine ; DOAJ Seal ; Essential Science Indicators ; Fees ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection
Click to display QR Code for this record

The record appears in these collections:
Document types > Articles > Journal Article
Institute Collections > INM > INM-3
Workflow collections > Public records
Publications database
Open Access

 Record created 2026-10-07, last modified 2026-10-07


OpenAccess:
Download fulltext PDF
Rate this document:

Rate this document:
1
2
3
 
(Not yet reviewed)