Project description:WT mice and mice lacking PTPN2 in T cells (PTPN2-CD4Cre mice) were treated with AOM/DSS to induce colorectal tumours. RNA was isolated from tumour and non-tumour tissues in the colon. Colon samples from water-treated WT and PTPN2-CD4Cre mice served as additional control. Total RNA was isolated and the samples sequenced for polyA enriched RNA.
Project description:We generated pluripotent stem cells (Mel1 hESC containing a GFP reporter driven by the endogenous insulin promoter) with a functional knock out of PTPN2 by CRISPR/Cas9 genome editing. KO or WT control stem cells were differentiated into beta-like cells (sBC), sorted for GFP, and prepared for deep sequencing.
Project description:Protein tyrosine phosphatase N2 (Ptpn2) is a type 1 diabetes (T1D) candidate gene identified from human genome-wide association studies. PTPN2 is highly expressed in human and murine islets and becomes elevated upon inflammation, suggesting that PTPN2 may be important for beta cell survival in the context of T1D. To test whether PTPN2 contributed to beta cell dysfunction in an inflammatory environment, we generated a beta cell-specific deletion of Ptpn2 in mice (Ptpn2 βKO). While unstressed animals exhibit normal metabolic profiles, streptozotocin (STZ) Ptpn2 βKO mice display marked increase in hyperglycemia and death due to exacerbated beta cell loss. Furthermore, cytokine treated Ptpn2 KO islets resulted in mitochondrial defects and reduced glucose-induced metabolic flux, suggesting beta cells lacking Ptpn2 are more susceptible to inflammatory stress associated with T1D due to compromised metabolic fitness.
Project description:Background & aims: Loss-of-function variants in the PTPN2 gene are associated with increased risk of inflammatory bowel disease. We recently showed that Ptpn2 is critical for intestinal epithelial cell (IEC) barrier maintenance, IEC-macrophage communication, and modulation of the gut microbiome in mice, restricting expansion of a small intestinal pathobiont associated with inflammatory bowel disease. Here, we aimed to identify how Ptpn2 loss affects ileal IEC subtypes and their function in vivo. Methods: Constitutive Ptpn2 wild-type, heterozygous, and knockout (KO) mice, as well as mice with inducible deletion of Ptpn2 in IECs, were used in the study. Investigation was performed using imaging techniques, flow cytometry, enteroid culture, and analysis of gene and protein levels of IEC markers. Results: Partial transcriptome analysis showed that expression of Paneth cell-associated antimicrobial peptides Lyz1, Pla2g2a, and Defa6 was down-regulated markedly in Ptpn2-KO mice compared with wild-type and heterozygous. In parallel, Paneth cell numbers were reduced, their endoplasmic reticulum architecture was disrupted, and the endoplasmic reticulum stress protein, C/EBP-homologous protein (CHOP), was increased in Ptpn2-KO mice. Despite reduced Paneth cell number, flow cytometry showed increased expression of the Paneth cell-stimulatory cytokines interleukin 22 and interferon γ+ in CD4+ T cells isolated from Ptpn2-KO ileum. Key findings in constitutive Ptpn2-KO mice were confirmed in epithelium-specific Ptpn2ΔIEC mice, which also showed impaired lysozyme protein levels in Paneth cells compared with Ptpn2fl/fl control mice. Conclusions: Constitutive Ptpn2 deficiency affects Paneth cell viability and compromises Paneth cell-specific antimicrobial peptide production. The observed effects may contribute to the increased susceptibility to intestinal infection and dysbiosis in these mice.
Project description:Loss-of-function variants in the protein tyrosine phosphatase non-receptor type 2 (PTPN2) gene are associated with increased risk of inflammatory bowel disease (IBD). PTPN2 encodes T cell protein tyrosine phosphatase (TCPTP), a negative regulator of several intracellular signaling pathways including JAK-STAT. It has been shown that Ptpn2 is critical for intestinal epithelial cell (IEC) barrier maintenance, IEC-macrophage communication, and modulation of the gut microbiome in mice. However, the mechanisms by which Ptpn2 influences the intestinal flora are unknown. In this study, we aimed to identify how Ptpn2-loss affects the expression of genes associated with function/differentiation of IECs in the small and large intestines that could contribute to higher susceptibility to infection.
Project description:Loss-of-function variants in the protein tyrosine phosphatase non-receptor type 2 (PTPN2) gene are associated with increased risk of inflammatory bowel disease (IBD). PTPN2 encodes T cell protein tyrosine phosphatase (TCPTP), a negative regulator of several intracellular signaling pathways including JAK-STAT. It has been shown that Ptpn2 is critical for intestinal epithelial cell (IEC) barrier maintenance, IEC-macrophage communication, and modulation of the gut microbiome in mice. However, the mechanisms by which Ptpn2 influences the intestinal flora are unknown. In this study, we aimed to identify how Ptpn2-loss affects the expression of genes associated with function/differentiation of IECs in the small and large intestines that could contribute to higher susceptibility to infection.
Project description:Loss-of-function variants in the protein tyrosine phosphatase non-receptor type 2 (PTPN2) gene are associated with increased risk of inflammatory bowel disease (IBD). PTPN2 encodes T cell protein tyrosine phosphatase (TCPTP), a negative regulator of several intracellular signaling pathways including JAK-STAT. It has been shown that Ptpn2 is critical for intestinal epithelial cell (IEC) barrier maintenance, IEC-macrophage communication, and modulation of the gut microbiome in mice. However, the mechanisms by which Ptpn2 influences the intestinal flora are unknown. In this study, we aimed to identify how Ptpn2-loss affects the expression of genes associated with function/differentiation of IECs in the small and large intestines that could contribute to higher susceptibility to infection.
Project description:Loss-of-function variants in the protein tyrosine phosphatase non-receptor type 2 (PTPN2) gene are associated with increased risk of inflammatory bowel disease (IBD). PTPN2 encodes T cell protein tyrosine phosphatase (TCPTP), a negative regulator of several intracellular signaling pathways including JAK-STAT. It has been shown that Ptpn2 is critical for intestinal epithelial cell (IEC) barrier maintenance, IEC-macrophage communication, and modulation of the gut microbiome in mice. However, the mechanisms by which Ptpn2 influences the intestinal flora are unknown. In this study, we aimed to identify how Ptpn2-loss affects the expression of genes associated with function/differentiation of IECs in the small and large intestines that could contribute to higher susceptibility to infection.
Project description:To investigate the function of Ptpn2, IFNγ and cGAS on axon regeneration, we performed gene transcription profiling of dorsal root ganglion neurons from 5 groups (WT, cKO, WT injured, cKO injured, RU521 injured) and retinal ganglion cells from 4 groups (WT, IFNγ, cKO, IFNγ+cKO).
Project description:Genetic variants at the PTPN2 locus, which encodes the tyrosine phosphatase PTPN2, cause reduced gene expression and are linked to rheumatoid arthritis (RA) and other autoimmune diseases. PTPN2 inhibits signaling through the T cell and cytokine receptors and loss of PTPN2 promotes T cell expansion and CD4 and CD8-driven autoimmunity. However, it remains unknown whether loss of PTPN2 in FoxP3+ regulatory T cells (Treg) plays a role in autoimmunity. Here we show that a reduction in Ptpn2 expression, comparable to that reported in human carriers of autoimmune-predisposing PTPN2 variants, unexpectedly enhances the severity of autoimmune arthritis through a Treg-intrinsic mechanism. Mechanistically, we found that through dephosphorylation of STAT3, Ptpn2 inhibits IL-6-driven pathogenic loss of FoxP3 after Tregs have acquired RORgt expression, at a stage when chromatin accessibility for STAT3-targeted IL-17 associated transcription factors is maximized. We conclude that PTPN2 promotes FoxP3 stability in RORgt+ Treg and that loss of function of PTPN2 in Treg contributes to the association between PTPN2 and autoimmunity.