GSK-3 mediates differentiation and activation of proinflammatory dendritic cells.

Department of Molecular Oncology/Hematology, German Cancer Research Center, Heidelberg, Germany.
Blood (Impact Factor: 9.78). 03/2007; 109(4):1584-92. DOI: 10.1182/blood-2006-06-028951
Source: PubMed

ABSTRACT The key components of the intracellular molecular network required for the expression of a specific function of dendritic cells (DCs) are as yet undefined. Using an in vitro model of human monocyte-derived DC differentiation, this study investigates the role of glycogen synthase kinase 3 (GSK-3), a multifunctional enzyme critical for cellular differentiation, apoptosis, self-renewal, and motility, in this context. We demonstrate that GSK-3 (1) inhibits macrophage development during differentiation of DCs, (2) is constitutively active in immature DCs and suppresses spontaneous maturation, and (3) acquires a proinflammatory functional status mediating high levels of IL-12, IL-6, and TNF-alpha secretion, and partially inhibits IL-10 in the context of DC activation. In particular, GSK-3 enhances IL-12p35 mRNA expression and thus the production of the proinflammatory cytokine IL-12p70 by integrating the activities of other kinases priming GSK-3 targets and the inhibitory effects of Akt-1. GSK-3 may therefore act as a key integrator of activating and inhibitory pathways involved in proinflammatory DC differentiation and activation.

1 Bookmark
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Infection and inflammation, through their ability to increase pro-inflammatory cytokines and chemokines and adhesion molecules, are thought to play a central role in the pathophysiology of insulin resistance and type 2 diabetes. Recent studies have shown that glycogen synthase kinase 3 (GSK3) plays a central role in regulating this inflammation. There are, however, no studies on the role of GSK3 in pregnancies complicated by gestational diabetes mellitus (GDM). Thus, the aims of this study were (i) to determine whether GSK3 is increased in adipose tissue and skeletal muscle from women with GDM; and (ii) to investigate the effect of GSK3 inhibition on inflammation in the presence of inflammation induced by bacterial endotoxin lipopolysaccharide (LPS) or the pro-inflammatory cytokine IL-1β. Human omental adipose tissue and skeletal muscle were obtained from normal glucose tolerant (NGT) women and BMI-matched women with diet-control GDM at the time of Caesarean section. Western blotting was performed to determine GSK3 protein expression. Tissue explants were performed to determine the effect of the GSK3 inhibitor CHIR99021 on markers of inflammation. When compared to women with NGT, omental adipose tissue and skeletal muscle obtained from women with diet-controlled GDM had significantly higher GSK3β activity as evidenced by a decrease in the expression of GSK3β phosphorylated at serine 9. The GSK3 inhibitor CHIR99021 significantly reduced the gene expression and secretion of the pro-inflammatory cytokines TNF-α, IL-1β and IL-6; the pro-inflammatory chemokines IL-8 and MCP-1; and the adhesion molecules ICAM-1 and VCAM-1 in tissues stimulated with LPS or IL-1β. In conclusion, GSK3 activity is increased in GDM adipose tissue and skeletal muscle and regulates infection- and inflammation-induced pro-inflammatory mediators.
    PLoS ONE 12/2014; 9(12):e115854. · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Dendritic cells (DCs), key players of immunity, are regulated by glycogen synthase kinase GSK3. GSK3 activity is suppressed by PKB/Akt and SGK isoforms, which are in turn stimulated by the PI3K pathway. Exposure to bacterial lipopolysaccharides increases cytosolic Ca(2+)-concentration ([Ca(2+)]i), an effect augmented in DCs isolated from mutant mice expressing PKB/SGK-resistant GSK3α,β (gsk3(KI) ). Factors affecting [Ca(2+)]i include Ca(2+)-release from intracellular stores (CRIS), store-operated Ca(2+)-entry (SOCE) through STIM1/STIM2-regulated Orai1, K(+)-dependent Na(+)/Ca(2+)-exchangers (NCKX), K(+)-independent Na(+)/Ca(2+)-exchangers (NCX) and calbindin-D28k. The present study explored whether PKB/SGK-dependent GSK3α, β-activity impacts on CRIS, SOCE, NCKX, NCX or calbindin. DCs were isolated from gsk3(KI) mice and respective wild-type mice (gsk3(WT) ), [Ca(2+)]i estimated from Fura2 fluorescence, Orai1, STIM1, STIM2 as well as calbindin-D28k protein abundance determined by Western blotting and mRNA levels quantified by real time PCR. As a result, thapsigargin-induced CRIS and SOCE were significantly blunted by GSK3-inhibitors SB216763 (1-10 µM, 30 min) or GSK-XIII (10 µM, 30 min) but were significantly lower in gsk3(WT) than in gsk3(KI) DCs. Orai1, STIM1 and STIM2 protein abundance was significantly lower and calbindin-D28k abundance significantly higher in gsk3(KI) than in gsk3(WT) DCs. Activity of NCKX and NCX was significantly higher in gsk3(KI) than in gsk3(WT) DCs and was significantly increased by SB216763 (1 µM, 30 min) or GSK-XIII (10 µM, 30 min). Treatment of gsk3(WT) DCs with SB216763 (1 µM, 4-24 h) or GSK-XIII (10 µM, 4-24 h) did not significantly modify the protein abundance of Orai1, STIM1 and STIM2. The present observations point to a dual role of GSK3 in the regulation of Ca(2+) in DCs. Acute inhibition of GSK3 blunted the increase of [Ca(2+)]i following CRIS and SOCE and stimulated NCKX/NCX activity. However, expression of PKB/SGK-resistant GSK3α, β downregulated the increase of [Ca(2+)]i following CRIS and SOCE, an effect at least partially due to downregulation of Orai1, STIM1 and STIM2 expression as well as upregulation of Na(+)/Ca(2+)-exchanger activity and calbindin D28k expression.
    PLoS ONE 01/2014; 9(2):e88637. · 3.53 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Neuroinflammation is a crucial mechanism related to many neurological diseases. Extensive studies in recent years have indicated that dysregulation of Glycogen Synthase Kinase 3 Beta (GSK3β) contributes to the development and progression of these disorders through regulating the neuroinflammation processes. Inhibitors of GSK3β have been shown to be beneficial in many neuroinflammatory disease models including Alzheimer's disease, multiple sclerosis and AIDS dem entia complex. Glial activation and elevated pro-inflammation cytokines (signs of neuroinflammation) in the spinal cord have been widely recognized as a pivotal mechanism underlying the development and maintenance of many types of pathological pain. The role of GSK3β in the pathogenesis of pain has recently emerged. In this review, we will first review the GSK3β structure, regulation, and mechanisms by which GSK3βregulates inflammation. We will then describe neuroinflammationin general and in specific types of neurological diseases and the potential beneficial effects induced by inhibiting GSK3β. Finally, we will provide new evidence linking aberrant levels of GSK3β in the development of pathological pain.
    Journal of pharmaceutics & pharmacology. 01/2013; 1(1):001.