Project description:The intricate aetiology of type 1 diabetes mellitus (T1DM) implicating a detrimental cross talk between immune cells and insulin producing -cells leading to their destruction has stumped the development of effective disease modifying therapies. The discovery that the pharmacological activation of LRH-1/NR5A2 can revert hyperglycemia in pre-clinical mouse models of T1DM by attenuating the autoimmune attack coupled to -cell survival/regeneration, prompt us to investigate whether LRH-1/NR5A2-mediated immune tolerization could be achieved in individuals with T1DM and improve islet survival and function subsequent to xenotransplantation. We found that LRH-1/NR5A2 activation using the agonist BL001 blunted the pro-inflammatory genetic signature and cytokine secretome of both monocyte-derived macrophages (MDM1) and mature dendritic cells (mDCs) from individuals with T1DM. Mechanistically, mitohormesis was induced in MDM1 restricting pro-inflammation propagation while mitochondria turnover was increased in mDCs assisting transit towards a tolerogenic phenotype. BL001 treatment also increased T-regulatory cells within the T-cell subpopulation. BL001-treated MDM1, mDCs or T-cells impeded T-effector cell expansion. Engraftment and function of human islets transplanted into hyperglycemic immunocompetent mice was enhanced by BL001 treatment leading to improved glycemia. Collectively, LRH-1/NR5A2 agonism fosters a coordinated re-programming of T1DM immune cells from a pro- to an anti-inflammatory/tolerizing phenotype empowering them to repress cytotoxic T-cell proliferation and facilitates islet engraftment and function after transplantation. Our finding demonstrate the feasibility of re-establishing human immune tolerance within a pro-inflammatory environment, rather than suppression, opening an unprecedent pharmacological therapeutic venue for T1DM.
Project description:The intricate aetiology of type 1 diabetes mellitus (T1DM) implicating a detrimental cross talk between immune cells and insulin producing b-cells leading to their destruction has stumped the development of effective disease modifying therapies. The discovery that the pharmacological activation of LRH-1/NR5A2 can revert hyperglycemia in pre-clinical mouse models of T1DM by attenuating the autoimmune attack coupled to b-cell survival/regeneration, prompt us to investigate whether LRH-1/NR5A2-mediated immune tolerization could be achieved in individuals with T1DM and improve islet survival and function subsequent to xenotransplantation. We found that LRH-1/NR5A2 activation using the agonist BL001 blunted the pro-inflammatory genetic signature and cytokine secretome of both monocyte-derived macrophages (MDM1) and mature dendritic cells (mDCs) from individuals with T1DM. Mechanistically, mitohormesis was induced in MDM1 restricting pro-inflammation propagation while mitochondria turnover was increased in mDCs assisting transit towards a tolerogenic phenotype. BL001 treatment also increased T-regulatory cells within the T-cell subpopulation. BL001-treated MDM1, mDCs or T-cells impeded T-effector cell expansion. Engraftment and function of human islets transplanted into hyperglycemic immunocompetent mice was enhanced by BL001 treatment leading to improved glycemia. Collectively, LRH-1/NR5A2 agonism fosters a coordinated re-programming of T1DM immune cells from a pro- to an anti-inflammatory/tolerizing phenotype empowering them to repress cytotoxic T-cell proliferation and facilitates islet engraftment and function after transplantation. Our finding demonstrate the feasibility of re-establishing human immune tolerance within a pro-inflammatory environment, rather than suppression, opening an unprecedent pharmacological therapeutic venue for T1DM
Project description:The ovarian reserve of follicles comprises all oocytes for lifetime fertility and is depleted by progressive activation. The orphan nuclear receptor liver receptor homolog 1 (LRH-1; Nr5a2) is essential for ovulation, but its role in the early stages of follicular development is not known. We therefore developed a model of conditional depletion of LRH-1 from early postnatal ovaries (postnatal day 4) and performed RNAsequencing to identify LRH-1 regulated genes during the earliest stages of follicular activation.
Project description:We report the gene expression changes in murine small intestinal organoids following deletion of LRH-1 (NR5A2) and humanization by expression of human LRH-1 in mouse LRH-1 knockout organoids.
Project description:Nr5a2 (also known as liver receptor homolog-1, Lrh-1) has been shown to bind both the proximal enhancer and proximal promoter regions of Pou5f1 and regulate Pou5f1 in the epiblast stage of mouse embryonic development (Gu et al., 2005). Nr5a2-null embryos display a loss of Oct4 expression in the epiblasts (Gu et al., 2005) and die between E6.5 and E7.5 (Gu et al., 2005; Pare et al., 2004). To identify the targets of Nr5a2, we generated a stable ES cell-line that expresses HA-tagged Nr5a2. Anti-HA antibody was used to immunoprecipitate HA-Nr5a2 for ChIP-seq analysis. Keywords: Transcription factor binding sites To identify the binding sites of Nr5a2, we generated a stable ES cell-line that expresses HA-tagged Nr5a2. Anti-HA antibody was used to immunoprecipitate HA-Nr5a2.
Project description:Pharmacological activation of LRH-1/NR5A2 triggers an anti-inflammatory phenotypic switch in immune cells from individuals with type 1 diabetes and improves human islet engraftment/function
Project description:Nr5a2 (also known as liver receptor homolog-1, Lrh-1) has been shown to bind both the proximal enhancer and proximal promoter regions of Pou5f1 and regulate Pou5f1 in the epiblast stage of mouse embryonic development (Gu et al., 2005). Nr5a2-null embryos display a loss of Oct4 expression in the epiblasts (Gu et al., 2005) and die between E6.5 and E7.5 (Gu et al., 2005; Pare et al., 2004). To identify the targets of Nr5a2, we generated a stable ES cell-line that expresses HA-tagged Nr5a2. Anti-HA antibody was used to immunoprecipitate HA-Nr5a2 for ChIP-seq analysis. Keywords: Transcription factor binding sites
Project description:Chronic endoplasmic reticulum (ER) stress results in toxicity that contributes to multiple human disorders. We report a stress resolution pathway initiated by the nuclear receptor LRH-1 that is independent of known unfolded protein response (UPR) pathways. Like mice lacking primary UPR components, hepatic Lrh-1-null mice cannot resolve ER stress, despite a functional UPR. In response to ER stress, LRH-1 induces expression of the kinase Plk3, which phosphorylates and activates the transcription factor ATF2. Plk3-null mice also cannot resolve ER stress, and restoring Plk3 expression in Lrh-1-null cells rescues ER stress resolution. Reduced or heightened ATF2 activity also sensitizes or desensitizes cells to ER stress, respectively. LRH-1 agonist treatment increases ER stress resistance and decreases cell death. We conclude that LRH-1 initiates a novel pathway of ER stress resolution that is independent of the UPR, yet equivalently required. Targeting LRH-1 may be beneficial in human disorders associated with chronic ER stress. 24 total samples. One sample represents one mouse. Three samples were analyzed from the following groups: Lrh-1 f/f (control littermates) treated with vehicle, Lrh-1 f/f treated with tunicamycin (TM; 1mg/kg BW for 24h), Lrh-1 f/f treated with tunicamycin and DLPC (100mg/kg BW 4x), Lrh-1 f/f treated with tunicamycin and vehicle for DLPC, Lrh-1 liver-specific KO mice (LKO) treated with vehicle, Lrh-1 LKO treated with tunicamycin, and Lrh-1 LKO treated with tunicamycin and DLPC, Lrh-1 LKO treated with tunicamycin and vehicle for DLPC