54 research outputs found

    Prostaglandin E2 stimulates the expansion of regulatory hematopoietic stem and progenitor cells in type 1 diabetes

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    Hematopoietic stem and progenitor cells (HSPCs) are multipotent stem cells that have been harnessed as a curative therapy for patients with hematological malignancies. Notably, the discovery that HSPCs are endowed with immunoregulatory properties suggests that HSPC-based therapeutic approaches may be used to treat autoimmune diseases. Indeed, infusion with HSPCs has shown promising results in the treatment of type 1 diabetes (T1D) and remains the only "experimental therapy" that has achieved a satisfactory rate of remission (nearly 60%) in T1D. Patients with newly diagnosed T1D have been successfully reverted to normoglycemia by administration of autologous HSPCs in association with a non-myeloablative immunosuppressive regimen. However, this approach is hampered by a high incidence of adverse effects linked to immunosuppression. Herein, we report that while the use of autologous HSPCs is capable of improving C-peptide production in patients with T1D, ex vivo modulation of HSPCs with prostaglandins (PGs) increases their immunoregulatory properties by upregulating expression of the immune checkpoint-signaling molecule PD-L1. Surprisingly, CXCR4 was upregulated as well, which could enhance HSPC trafficking toward the inflamed pancreatic zone. When tested in murine and human in vitro autoimmune assays, PG-modulated HSPCs were shown to abrogate the autoreactive T cell response. The use of PG-modulated HSPCs may thus provide an attractive and novel treatment of autoimmune diabetes

    P2X7R mutation disrupts the NLRP3-mediated Th program and predicts poor cardiac allograft outcomes

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    Purinergic receptor-7 (P2X7R) signaling controls Th17 and Th1 generation/differentiation, while NOD-like receptor P3 (NLRP3) acts as a Th2 transcriptional factor. Here, we demonstrated the existence of a P2X7R/NLRP3 pathway in T cells that is dysregulated by a P2X7R intracellular region loss-of-function mutation, leading to NLRP3 displacement and to excessive Th17 generation due to abrogation of the NLRP3-mediated Th2 program. This ultimately resulted in poor outcomes in cardiac-transplanted patients carrying the mutant allele, who showed abnormal Th17 generation. Transient NLRP3 silencing in nonmutant T cells or overexpression in mutant T cells normalized the Th profile. Interestingly, IL-17 blockade reduced Th17 skewing of human T cells in vitro and abrogated the severe allograft vasculopathy and abnormal Th17 generation observed in preclinical models in which P2X7R was genetically deleted. This P2X7R intracellular region mutation thus impaired the modulatory effects of P2X7R on NLRP3 expression and function in T cells and led to NLRP3 dysregulation and Th17 skewing, delineating a high-risk group of cardiac-transplanted patients who may benefit from personalized therapy

    Asymmetric multicomponent copper catalyzed synthesis of chiral propargylamines

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    A three-component stereoselective reaction between an aldehyde, an amine and phenylacetylene to afford optically active propargyl amines in good yields was developed. The reaction is catalysed by copper complexes of enantiomerically pure bis-imines. The best results were obtained with imines readily prepared in very high yields from the commercially available binaphtyl diamine. A very simple experimental procedure at room temperature allowed to obtain optically active propargyl amines in very good yields and enantioselectivity up to 75%. The extremely simple methodology and the mild reaction conditions, as well as the possibility of a modular approach for developing new and more efficient bis-imine-based chiral ligands make the present methodology very attractive

    Very mild, enantioselective synthesis of propargylamines catalyzed by copper(I)-bisimine complexes

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    The stereoselective addition of aryl- and alkylacetylene derivatives to imines was studied. The reaction is catalyzed by copper complexes of enantiomerically pure bisimines, readily prepared in very high yields from the commercially available binaphthyl diamine. A very simple experimental procedure allowed to obtain at room temperature optically active propargylamines in high yields and enantioselectivity. Interestingly, bisimine/copper(I) complexes were able to promote the direct, enantioselective, catalytic addition to imines of alkylacetylenes. The effects of catalyst loading and other reaction parameters on the stereochemical outcome of the transformation were investigated. The extremely convenient methodology, the mild reaction conditions, and the possibility of a modular approach for developing new and more efficient bisimine-based chiral ligands make the present methodology very attractive

    Age-Related Outcome of Mobile-Bearing Total Ankle Replacement

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    The aim of this study was to investigate clinical and radiographic outcomes in patients 50 years and younger vs patients older than 50 years undergoing total ankle replacement. Seventy consecutive patients who underwent primary total ankle replacement were included in this retrospective study. Patients were assessed clinically and radiographically. There was a statistically significant difference between the 2 groups for the American Orthopaedic Foot & Ankle Society score at final follow-up. The younger group had significantly greater improvement compared with the older group. Total ankle arthroplasty is an effective treatment for young, active patients with symptomatic end-stage ankle arthritis. [Orthopedics. 2017; 40(3):e567-e573.]

    Total ankle replacement: is pre-operative varus deformity a predictor of poor survival rate and clinical and radiological outcomes?

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    PURPOSE: The objective of this study was to compare survival rate and clinical and radiological outcomes of a cementless mobile-bearing total ankle replacement (TAR) between two groups of patients, affected by end-stage ankle arthritis, with or without a pre-operative varus deformity. METHODS: A total of 81 patients (81 ankles) were included in the study and divided in two groups. Group A, "varus" group, includes 11 patients with pre-operative varus deformity of more than 10\ua0\ub0 and group B, "neutral" group, includes 70 patients, with a varus/valgus deformity of less than 10\ua0\ub0. American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, visual analogue scale (VAS), and Short Form (SF)-12 score were used to compare clinical outcomes. Radiological parameters, complications, and survival rate at last follow-up were also recorded. RESULTS: In both groups, all clinical and radiological parameters improved after surgery (p\ua0\u20090.001). CONCLUSIONS: Severe varus malalignment should not be considered a contraindication for a mobile-bearing TAR. Nevertheless, TAR in severe deformity should be performed only by experienced surgeons

    The rise, fall, and resurgence of immunotherapy in type 1 diabetes

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    Despite considerable effort to halt or delay destruction of \u3b2-cells in autoimmune type 1 diabetes (T1D), success remains elusive. Over the last decade, we have seen a proliferation of knowledge on the pathogenesis of T1D that emerged from studies performed in non-obese diabetic (NOD) mice. However, while results of these preclinical studies appeared to hold great promise and boosted patients' hopes, none of these approaches, once tested in clinical settings, induced remission of autoimmune diabetes in individuals with T1D. The primary obstacles to translation reside in the differences between the human and murine autoimmune responses and in the contribution of many environmental factors associated with the onset of disease. Moreover, inaccurate dosing as well as inappropriate timing and uncertain length of drug exposure have played a central role in the negative outcomes of such therapeutic interventions. In this review, we summarize the most important approaches tested thus far in T1D, beginning with the most successful preclinical studies in NOD mice and ending with the latest disappointing clinical trials in humans. Finally, we highlight recent stem cell-based trials, for which expectations in the scientific community and among individuals with T1D are high

    The use of hematopoietic stem cells in autoimmune diseases

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    Hematopoietic stem cells (HSCs) have been shown recently to hold much promise in curing autoimmune diseases. Newly diagnosed Type 1 diabetes individuals have been successfully reverted to normoglycemia by administration of autologous HSCs in association with a nonmyeloablative regimen (antithymocyte globulin + cyclophasmide). Furthermore, recent trials reported positive results by using HSCs in treatment of systemic sclerosis, multiple sclerosis and rheumatoid arthritis as well. Early data suggested that HSCs possess immunological properties that may be harnessed to alleviate the symptoms of individuals with autoimmune disorders and possibly induce remission of autoimmune diseases. Mechanistically, HSCs may facilitate the generation of regulatory T cells, may inhibit the function of autoreactive T-cell function and may reshape the immune system

    Sodium glucose cotransporters inhibitors in type 1 diabetes

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    Sodium glucose cotransporter inhibitors (SGLTi) are oral hypoglycemic drugs that reduce renal glucose re-uptake and induce glycosuria. SGLTi have been successfully tested in large randomized clinical trials for type 2 diabetes, and several molecules have been approved in this setting by the international pharmaceutical agencies. Additionally, recent evidence has shown that SGLTi may be useful also in type 1 diabetes (T1D). Indeed, these drugs can be used as an ancillary to insulin to improve glycemic control and reduce insulin dosage, and such regimens have been associated with a lower rate of hypoglycemic episodes. The pharmacological effects of SGLTi therapy are described herein, and we also discuss the future use of SGLTi in T1D
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