Glycogen Synthase Kinase 3β Activation Is a Prerequisite Signal for Cytokine Production and Chemotaxis in Human Mast Cells

Abstract

In addition to regulating mast cell homeostasis, the activation of KIT following ligation by stem cell factor promotes a diversity of mast cell responses, including cytokine production and chemotaxis. Although we have previously defined a role for the mammalian target of rapamycin complex 1 in these responses, it is clear that other signals are also required for maximal KIT-dependent cytokine production and chemotaxis. In this study, we provide evidence to support a role for glycogen synthase kinase 3β (GSK3β) in such regulation in human mast cells (HuMCs). GSK3β was observed to be constitutively activated in HuMCs. This activity was inhibited by knockdown of GSK3β protein following transduction of these cells with GSK3β-targeted shRNA. This resulted in a marked attenuation in the ability of KIT to promote chemotaxis and, in synergy with FcεRI-mediated signaling, cytokine production. GSK3β regulated KIT-dependent mast cell responses independently of mammalian target of rapamycin. However, evidence from the knockdown studies suggested that GSK3β was required for activation of the MAPKs, p38, and JNK and downstream phosphorylation of the transcription factors, Jun and activating transcription factor 2, in addition to activation of the transcription factor NF-κB. These studies provide evidence for a novel prerequisite priming mechanism for KIT-dependent responses regulated by GSK3β in HuMCs.

mTORC1 and mTORC2 differentially regulate homeostasis of neoplastic and non-neoplastic human mast cells

“…Cells were cultured as described previously, 17 and 7-to 9-week-old huMCs were used for experiments. LAD2, 18 HMC-1.1, 19 and HMC-1.2 20 MCs were cultured as described previously.…”

GSK3β regulates physiological migration of stem/progenitor cells via cytoskeletal rearrangement

“…Additionally, the mere concept of a circadian molecular clock controlling HSPC egress supports the notion of highly regulated homeostasis of HSPC trafficking (48). Several reports have described a function for GSK3β in cell motility (13)(14)(15)(16), but it has not been determined whether it plays any role in immature hematopoietic cell motility.…”

“…Glycogen synthase kinase-3β (GSK3β) is a well-established negative regulator of the Wnt/β-catenin pathway, implicated in self-renewal and development of human and murine HSCs (3)(4)(5)(6)(7)(8)(9)(10)(11). In addition to proliferation, GSK3β has been shown to be involved in the motility of various cells, including microglia, epidermal stem cells, human mast cells, and breast cancer cells (12)(13)(14)(15)(16), but its effect on the motility of immature hematopoietic cells has not been addressed. On the other hand, the chemokine CXCL12 (also termed stromal-derived factor-1, referred to herein as SDF-1) and its major receptor CXCR4 have well-characterized roles in directional motility and quiescence of human and murine HSPCs (17)(18)(19)(20).…”

NK cell function triggered by multiple activating receptors is negatively regulated by glycogen synthase kinase-3β

“…Inhibition of GSK-3 by pharmacological agents and molecular manipulation (e.g., genetic deficiency or knockdown) greatly but not uniformly influences the inflammatory cytokine and chemokine repertoire triggered by diverse stimuli in monocytes, dendritic cells, mast cells, and T cells [28][29][30][31][32][33]. These studies indicate that immune cell functions affected by GSK-3 appear to be diverse and context-dependent according to the types of stimuli and immune cells.…”