Project description:Nuclear factor of activated T cells (NFAT) comprises a family of transcription factors that regulate T cell development, activation and differentiation. NFAT signaling can also mediate granulocyte and DC activation, but it is unknown whether NFAT influences their development from progenitors. Here we report a novel role for calcineurin/NFAT signaling as a negative regulator of myeloid hematopoiesis. Reconstituting lethally-irradiated mice with hematopoietic stem cells expressing an NFAT-inhibitory peptide resulted in enhanced development of the myeloid compartment. Culturing bone marrow cells with Flt3-L and Cyclosporin A, which inhibits NFAT signaling, increased numbers of differentiated DC. Global gene expression analysis of untreated DC and NFAT-inhibited DC revealed differential expression of transcripts that regulate cell cycle and apoptosis. Thus, calcineurin/NFAT signaling negatively regulates myeloid lineage development. The finding that NFAT acts as a negative regulator of myeloid development provides novel insight in understanding immune responses during treatment with calcineurin/NFAT inhibitors as Cyclosporin A. bone marrow cells from C57B/6 mice were stimulated in Flt3-L suplemented media in presence or absence of calcineurin/NFAT inhibitor Cyclosporin A, samples in 3 biological replicates
Project description:Nuclear factor of activated T cells (NFAT) comprises a family of transcription factors that regulate T cell development, activation and differentiation. NFAT signaling can also mediate granulocyte and DC activation, but it is unknown whether NFAT influences their development from progenitors. Here we report a novel role for calcineurin/NFAT signaling as a negative regulator of myeloid hematopoiesis. Reconstituting lethally-irradiated mice with hematopoietic stem cells expressing an NFAT-inhibitory peptide resulted in enhanced development of the myeloid compartment. Culturing bone marrow cells with Flt3-L and Cyclosporin A, which inhibits NFAT signaling, increased numbers of differentiated DC. Global gene expression analysis of untreated DC and NFAT-inhibited DC revealed differential expression of transcripts that regulate cell cycle and apoptosis. Thus, calcineurin/NFAT signaling negatively regulates myeloid lineage development. The finding that NFAT acts as a negative regulator of myeloid development provides novel insight in understanding immune responses during treatment with calcineurin/NFAT inhibitors as Cyclosporin A.
Project description:Calcineurin/NFAT signaling pathway has been shown to play important roles in various tissues such as the immune system, cardiac muscle and neuron. Although recent studies have shown that the pathway is involved in the regulation of hair growth, the precise mechanism is still unclear. In this study, we examine the molecular mechanism which is regulated by calcineurin/NFAT pathway, using two specific inhibitors for the pathway. Transcriptional profiling of human keratinocyte cell line, PHK cells, comparing control untreated PHK cells with cyclosporin A (CsA)-treated or 11R-VIVIT-treated PHK cells. Goal was to identify the effects of NFAT inhibitors on PHK cell proliferation. Cyclosporine A is a chemical compound, which strongly inhibits calcineurin phosphatase activity cooperating with cyclophilin, resulting in inhibition of NFAT signaling pathway. 11R-VIVIT is a cell-permeable peptide, which specifically interacts with NFAT and inhibits its binding to calcineurin, resulting in competitive inhibition of NFAT signaling pathway. Three-condition experiment; untreated PHK cells, CsA-treated PHK cells and 11R-VIVIT-treated PHK cells. Supplementary files: Significantly up-regulated genes across 4 different comparisons.
Project description:Complex regulatory mechanisms control continuous maintenance of myeloid progenitors and renewal of differentiated cells. Transcription factors play a important role in these processes. Here we report that the activation the calcineurin-NFAT signaling pathway inhibit the proliferation of myeloid granulocyte-monocyte progenitor (GMP). Myeloid progenitor subtypes possessed different susceptibilities to Ca2+ flux induction and consequently differential engagement of the calcineurin-NFAT pathway. This study show that inhibition of the calcineurin-NFAT pathway enhanced proliferation of GMPs both in vivo and in vitro. The calcineurin-NFAT signaling in GMPs is initiated through Flt3-L. The inhibition of the calcineurin-NFAT pathway altered the expression of the cell cycle regulation genes CDK4, CDK6, and CDKN1A, thus enabling faster cell cycle progression. The extensive use of NFAT inhibitors in the clinic should take into account that, in addition to the immunosuppression role in lymphoid cells, these NFAT inhibitors also affect the maintenance of the myeloid compartment. Microarray technology was used to understand the effects of NFAT inhibitors on C-kit enriched lineage negative cells.
Project description:Calcineurin/NFAT signaling pathway has been shown to play important roles in various tissues such as the immune system, cardiac muscle and neuron. Although recent studies have shown that the pathway is involved in the regulation of hair growth, the precise mechanism is still unclear. In this study, we examine the molecular mechanism which is regulated by calcineurin/NFAT pathway, using two specific inhibitors for the pathway. Transcriptional profiling of human keratinocyte cell line, PHK cells, comparing control untreated PHK cells with cyclosporin A (CsA)-treated or 11R-VIVIT-treated PHK cells. Goal was to identify the effects of NFAT inhibitors on PHK cell proliferation. Cyclosporine A is a chemical compound, which strongly inhibits calcineurin phosphatase activity cooperating with cyclophilin, resulting in inhibition of NFAT signaling pathway. 11R-VIVIT is a cell-permeable peptide, which specifically interacts with NFAT and inhibits its binding to calcineurin, resulting in competitive inhibition of NFAT signaling pathway.
Project description:Treatment of post-transplant patients with immunosuppressive drugs targeting the calcineurin-NFAT pathway, such as Cyclosporine A or Tacrolimus, are commonly associated with a higher incidence of opportunistic infections, such as Aspergillus fumigatus, which can lead to severe life-threating conditions. A component of the A. fumigatus cell wall, β-glucan, is recognized by dendritic cells via the Dectin-1 receptor, triggering downstream signaling that leads to calcineurin-NFAT binding, NFAT translocation, and transcription of NFAT-regulated genes. Here, we address the question of whether calcineurin signaling in CD11c-expressing cells, such as DCs, has a specific role in the innate control of A. fumigatus. Impairment of calcineurin in CD11c-expressing cells (CD11ccrecnb1loxP) significantly increased susceptibility to systemic A. fumigatus infection and to intranasal infection in irradiated mice undergoing bone marrow transplant. Global expression profiling of bone marrow-derived DCs identified calcineurin-regulated processes in the immune response to infection, including expression of pentraxin-3, an important anti-fungal defense protein. These results suggest that calcineurin inhibition directly impairs important immunoprotective functions of myeloid cells, as shown by the higher susceptibility of CD11ccrecnbloxP mice in models of systemic and invasive pulmonary aspergillosis, including after allogeneic bone marrow transplantation. These findings are relevant to the clinical management of transplant patients with severe Aspergillus infections.
Project description:Inhibition of calcineurin-NFAT pathway at the early stage can block somatic cell reprogramming. In order to study how the calcineurin-NFAT pathway contributes to the early stage of reprogramming, we designed this microarray experiment and tried to find out which genes or signalings were changed after inhibition of calcineurin-NFAT signaling by CSA (a specific inhibitor of calcineurin-NFAT pathway).
Project description:Vascular malformations are congenital lesions caused by somatic and germline mutations that disrupt developmental signaling pathways. Capillary malformations (CMs) typically present as port-wine stains in the skin and can also affect ocular and cerebral tissues in Sturge Weber Syndrome (SWS), leading to aesthetic, neurological, and ophthalmic complications. CMs are caused by a somatic mosaic mutation in the GNAQ gene in endothelial cells, leading to an activating p.R183Q substitution in the Gαq protein. The underlying mechanisms of Gαq-R183Q-driven CMs formation still remain unclear. To address this, we generated CRISPR/Cas9-engineered human dermal microvascular endothelial cells lacking endogenous Gαq, whilst expressing the Gαq-R183Q mutant instead. The Gαq-R183Q mutation strongly impaired endothelial cell migration and angiogenic sprouting capacity compared to wild-type controls. Next, using SILAC-based quantitative proteomics, we investigated the Gαq-R183Q-induced changes in the endothelial phosphoproteome. These analyses revealed prominent activation of calcineurin-NFAT signaling pathway in Gαq-R183Q-expressing endothelial cells, leading to dephosphorylation of NFAT1 and NFAT2 and the selective expression of their transcriptional target DSCR1.4. Immunofluorescence of patient-derived skin biopsies confirmed deregulation of NFAT1/2 and the expression of DSRC1 in endothelial cells, validating their potential importance in CMs. We further demonstrate that pharmacological inhibition of calcineurin with tacrolimus (FK506) could partially restore NFAT signaling, collective cell migration and sprouting in Gαq-R183Q endothelial cells. Intriguingly, the genetic depletion of the NFAT target DSCR1 in Gαq-R183Q cells fully rescued calcineurin/NFAT signaling as well as key endothelial functions. In summary, we uncovered a calcineurin-NFAT-DSCR1.4 signal transduction axis that is driven by Gαq-R183Q and established its importance for endothelial angiogenic properties. These findings highlight that calcineurin/NFAT signaling represents a promising therapeutic target to restore endothelial function in CMs.