Inflammation-induced glycolytic switch controls suppressivity of mesenchymal stem cells via STAT1 glycosylation.
R JitschinMartin BöttcherD SaulSoeren LukassenH BrunsR LoschinskiA B EkiciAndré ReisAndreas MackensenD MougiakakosPublished in: Leukemia (2019)
Mesenchymal stem cells (MSCs) represent key contributors to tissue homeostasis and promising therapeutics for hyperinflammatory conditions including graft-versus-host disease. Their immunomodulatory effects are controlled by microenvironmental signals. The MSCs' functional response towards inflammatory cues is known as MSC-"licensing" and includes indoleamine 2,3-dioxygenase (IDO) upregulation. MSCs use tryptophan-depleting IDO to suppress T-cells. Increasing evidence suggests that several functions are (co-)determined by the cells' metabolic commitment. MSCs are capable of both, high levels of glycolysis and of oxidative phosphorylation. Although several studies have addressed alterations of the immune regulatory phenotype elicited by inflammatory priming metabolic mechanisms controlling this process remain unknown. We demonstrate that inflammatory MSC-licensing causes metabolic shifts including enhanced glycolysis and increased fatty acid oxidation. Yet, only interfering with glycolysis impacts IDO upregulation and impedes T-cell-suppressivity. We identified the Janus kinase (JAK)/signal transducer and activator of transcription (STAT)1 pathway as a regulator of both glycolysis and IDO, and show that enhanced glucose turnover is linked to abundant STAT1 glycosylation. Inhibiting the responsible O-acetylglucosamine (O-GlcNAc) transferase abolishes STAT1 activity together with IDO upregulation. Our data suggest that STAT1-O-GlcNAcylation increases its stability towards degradation thus sustaining downstream effects. This pathway could represent a target for interventions aiming to enhance the MSCs' immunoregulatory potency.
Keyphrases
- mesenchymal stem cells
- cell proliferation
- umbilical cord
- oxidative stress
- bone marrow
- signaling pathway
- induced apoptosis
- transcription factor
- poor prognosis
- fatty acid
- cell therapy
- diabetic rats
- stem cells
- pi k akt
- machine learning
- small molecule
- cell cycle arrest
- physical activity
- high glucose
- big data
- hydrogen peroxide
- long non coding rna
- endothelial cells
- tyrosine kinase
- inflammatory response
- weight loss
- postmenopausal women
- blood pressure
- artificial intelligence
- stress induced
- metabolic syndrome
- adipose tissue