Effect of Probiotic Administration on Serum Tryptophan Metabolites in Pediatric Type 1 Diabetes Patients

Type 1 diabetes (T1D) is characterized by anomalous functioning of the immuno regulatory, tryptophan-catabolic enzyme indoleamine 2,3 dioxygenase 1 (IDO1). In T1D, the levels of kynurenine—the first byproduct of tryptophan degradation via IDO1—are significantly lower than in nondiabetic controls, such that defective immune regulation by IDO1 has been recognized as potentially contributing to autoimmunity in T1D. Because tryptophan catabolism—and the production of immune regulatory catabolites—also occurs via the gut microbiota, we measured serum levels of tryptophan, and metabolites thereof, in pediatric, diabetic patients after a 3-month oral course of Lactobacillus rhamnosus GG. Daily administration of the probiotic significantly affected circulating levels of tryptophan as well as the qualitative pattern of metabolite formation in the diabetic patients, while it decreased inflammatory cytokine production by the patients. This study suggests for the first time that a probiotic treatment may affect systemic tryptophan metabolism and restrain proinflammatory profile in pediatric T1D

Identification of a 2-propanol analogue modulating the non-enzymatic function of indoleamine 2,3-dioxygenase 1

Abstract Indoleamine 2,3 dioxygenase 1 (IDO1) is a metabolic enzyme that catalyzes the conversion of the essential amino acid tryptophan (Trp) into a series of immunoactive catabolites, collectively known as kynurenines. Through the depletion of Trp and the generation of kynurenines, IDO1 represents a key regulator of the immune responses involved in physiologic homeostasis as well as in neoplastic and autoimmune pathologies. The IDO1 enzyme has been described as an important immune checkpoint to be targeted by catalytic inhibitors in the treatment of cancer. In contrast, a defective expression/activity of the enzyme has been demonstrated in autoimmune diseases. Beside its catalytic activity, the IDO1 protein is endowed with an additional function associated with the presence of two immunoreceptor tyrosine-based inhibitory motifs (ITIMs), which, once phosphorylated, bind SHP phosphatases and mediate a long-term immunoregulatory activity of IDO1. Herein, we report the screening of a focused library of molecules bearing a propanol core by a protocol combining microscale thermophoresis (MST) analysis and a cellular assay. As a result, the combined screening identified a 2-propanolol analogue, VIS351, as the first potent activator of the ITIM-mediated function of the IDO1 enzyme. VIS351 displayed a good dissociation constant (Kd = 1.90 μM) for IDO1 and a moderate cellular inhibitor activity (IC50 = 11.463 μM), although it did not show any catalytic inhibition of the recombinant IDO1 enzyme. Because we previously demonstrated that the enzymatic and non-enzymatic (i.e., ITIM-mediated) functions of IDO1 reside in different conformations of the protein, we hypothesized that in the cellular system VIS351 may shift the dynamic conformational balance towards the ITIM-favoring folding of IDO1, resulting in the activation of the signaling rather than catalytic activity of IDO1. We demonstrated that VIS351 activated the ITIM-mediated signaling of IDO1 also in mouse plasmacytoid dendritic cells, conferring those cells an immunosuppressive phenotype detectable in vivo. Thus the manuscript describes for the first time a small molecule as a positive modulator of IDO1 signaling function, paving the basis for an innovative approach to develop first-in-class drugs acting on the IDO1 target

Tibiotalocalcaneal arthrodesis in a rare case of tuberculosis of the talus

Aim To assess our personal experience of a case of tuberculosis of the talus, and to provide an overview of the literature about this tuberculosis manifestations, including all its aspects: epidemiology, clinical and imaging presentation, and all the treatments available to the current state of knowledge. Methods We present our experience in a case of a 34-year-old patient, who came to our attention with difficulty in walking and pain due to a talar tuberculosis, with consequent bone disruption and reabsorption, and foot deformities. Results A tibiotalocalcaneal arthrodesis with retrograde nail and bone graft was performed after antibiotic therapy. Today, almost two years after treatment, the patient can walk independently with no major limitations in everyday life. Conclusion Tibiotalocalcaneal arthrodesis with bone graft showed good functional results in this case study, with complete graft fusion and good functional and radiological outcomes

Novel mutations in the WFS1 gene are associated with Wolfram syndrome and systemic inflammation

Mutations in the WFS1 gene, encoding wolframin (WFS1), cause endoplasmic reticulum (ER) stress and are associated with a rare autosomal-recessive disorder known as Wolfram syndrome (WS). WS is clinically characterized by childhood-onset diabetes mellitus, optic atrophy, deafness, diabetes insipidus and neurological signs. We identified two novel WFS1 mutations in a patient with WS, namely, c.316-1G > A (in intron 3) and c.757A > T (in exon 7). Both mutations, located in the N-terminal region of the protein, were predicted to generate a truncated and inactive form of WFS1. We found that although the WFS1 protein was not expressed in peripheral blood mononuclear cells (PBMCs) of the proband, no constitutive ER stress activation could be detected in those cells. In contrast, WS proband's PBMCs produced very high levels of proinflammatory cytokines (i.e. TNF-α, IL-1β, and IL-6) in the absence of any stimulus. WFS1 silencing in PBMCs from control subjects by means of small RNA interference also induced a pronounced proinflammatory cytokine profile. The same cytokines were also significantly higher in sera from the WS patient as compared to matched healthy controls. Moreover, the chronic inflammatory state was associated with a dominance of proinflammatory T helper 17 (Th17)-type cells over regulatory T (Treg) lymphocytes in the WS PBMCs. The identification of a state of systemic chronic inflammation associated with WFS1 deficiency may pave the way to innovative and personalized therapeutic interventions in WS

Engagement of nuclear coactivator 7 by 3-hydroxyanthranilic acid enhances activation of aryl hydrocarbon receptor in immunoregulatory dendritic cells

Indoleamine 2,3-dioxygenase 1 (IDO1) catalyzes the first step in the kynurenine pathway of tryptophan (Trp) degradation that produces several biologically active Trp metabolites. L-kynurenine (Kyn), the first byproduct by IDO1, promotes immunoregulatory effects via activation of the Aryl hydrocarbon Receptor (AhR) in dendritic cells (DCs) and T lymphocytes. We here identified the nuclear coactivator 7 (NCOA7) as a molecular target of 3-hydroxyanthranilic acid (3-HAA), a Trp metabolite produced downstream of Kyn along the kynurenine pathway. In cells overexpressing NCOA7 and AhR, the presence of 3-HAA increased the association of the two molecules and enhanced Kyn-driven, AhR-dependent gene transcription. Physiologically, conventional (cDCs) but not plasmacytoid DCs or other immune cells expressed high levels of NCOA7. In cocultures of CD4+ T cells with cDCs, the co-addition of Kyn and 3-HAA significantly increased the induction of Foxp3+ regulatory T cells and the production of immunosuppressive transforming growth factor β in an NCOA7-dependent fashion. Thus, the co-presence of NCOA7 and the Trp metabolite 3-HAA can selectively enhance the activation of ubiquitary AhR in cDCs and consequent immunoregulatory effects. Because NCOA7 is often overexpressed and/or mutated in tumor microenvironments, our current data may provide evidence for a new immune check-point mechanism based on Trp metabolism and AhR

Deficiency of immunoregulatory indoleamine 2,3-dioxygenase 1 in juvenile diabetes

A defect in indoleamine 2,3-dioxygenase 1 (IDO1), which is responsible for immunoregulatory tryptophan catabolism, impairs development of immune tolerance to autoantigens in NOD mice, a model for human autoimmune type 1 diabetes (T1D). Whether IDO1 function is also defective in T1D is still unknown. We investigated IDO1 function in sera and peripheral blood mononuclear cells (PBMCs) from children with T1D and matched controls. These children were further included in a discovery study to identify SNPs in IDO1 that might modify the risk of T1D. T1D in children was characterized by a remarkable defect in IDO1 function. A common haplotype, associated with dysfunctional IDO1, increased the risk of developing T1D in the discovery and also confirmation studies. In T1D patients sharing such a common IDO1 haplotype, incubation of PBMCs in vitro with tocilizumab (TCZ) - an IL-6 receptor blocker - would, however, rescue IDO1 activity. In an experimental setting with diabetic NOD mice, TCZ was found to restore normoglycemia via IDO1-dependent mechanisms. Thus, functional SNPs of IDO1 are associated with defective tryptophan catabolism in human T1D, and maneuvers aimed at restoring IDO1 function would be therapeutically effective in at least a subgroup of T1D pediatric patients.The authors wish to thank patients and subjects who participated in this study, as well as nurses and staff of the Pediatric Clinic of S. Maria della Misericordia Hospital (Perugia), Juvenile Diabetes Center-Anna Meyer Children's Hospital (Florence), Unit of Endocrinology and Diabetes-'Bambino Gesu' Children's Hospital (Rome), Hopital Necker-Enfants Malades (Paris), and Diabetes and Metabolism Service-University Hospital Centre of Coimbra (Coimbra). The authors wish also to thank Roberto Gerli for the gift of TCZ, Giovanni Ricci for histologies, and Francisco Carrilho and Eduarda Coutinho for providing and processing, respectively, DNA samples from the Portuguese cohorts. This work was supported by the European Research Council (338954-DIDO to UG) and, in part, by Associazione per l'Aiuto ai Giovani con Diabete Italia e dell'Umbria (to UG) and the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER) (NORTE-01-0145-FEDER-000013 to AC) and the Fundacao para a Ciencia e Tecnologia (contracts IF/00735/2014 to AC, and SFRH/BPD/96176/2013 to CC).info:eu-repo/semantics/publishedVersio

Percutaneous repair of Achilles tendon: a ten years follow-up

The incidence of Achilles tendon ruptures is constantly increasing, probably as a result of the increment of recreational sport activities. Percutaneous tendon repair, described for the first time in 1977 by Ma and Griffith, minimize many of complications that accompany open surgical repairs and combine the advantages of surgical and non surgical management. Currently this technique is obtaining increasing popularity and is considered safe and effective in repairing ruptured Achilles tendons. We use this procedure, modified, from 1997 and the purpose of this study is the evaluation of long term results of the first 20 cases operated between 1997 and 1999. At follow-up the control patients were evaluated subjectively with a questionnaire and clinically with a sensory assessment, measurement of calf circumference, ankle range of motion and a stress test with the patient on bilateral and unilateral tip toe. Moreover we performed bilateral ultrasonography examinations to control tendon healing and size and MRI evaluation for a more accurate study of tendon structure and thickness. The overall results were good. No re-ruptures. We confirm an increase of Achilles tendon thickness without structural impairments. At long term follow-up percutaneous repair proved tobe a simple, safe, reliable, low cost procedure with a high patient’s compliance

Modular prosthesis with a silver coating for periarticular reconstruction in septic prosthetic and post-traumatic failures

Introduction Infection in orthopaedic surgery is a dreadful complication. Patients are often subjected to several surgeries with prolonged antibiotic treatment, and the risk of persistent infection and debilitating functional outcome is high. Often, a massive bone defect coexists, linked to the need to perform extensive debridement to remove necrotic or infected bone. The antimicrobial activity of silver ion has been known since ancient times (silver vases and cisterns for drinking water) and in recent years has been revived in everyday life (toothbrushes, underwear) as well as in medicine (wound dressings). Materials and methods Recently, we developed an evolution of the modular prosthesis MegasystemC (Waldemar Link, Hamburg, Germany) with a silver coating (PorAg) and, at our Centre, from June 2010 to February 2012 were operated on 10 patients with septic arthroplasty (4 cases, 2 hips and 2 knees) or septic meta-epiphyseal post-traumatic deformity or nonunion (5 cases, 1 proximal and 4 distal femur) and on a patient affected by an epithelioid hemangioendothelioma of the distal femur with a previous infected biopsy. One patient with subtrochanteric nonunion was subjected to only 1 surgery before resection and modular silver-coating prosthesis, while in all other cases the number of previous surgeries ranged from 3 to 8. In 7 cases the infection had resolved, while in 3 cases the infection was persistent (1 knee arthrodesis prosthesis as a results of septic knee megaprosthesis and the subtrochanteric nonunion) and it was decided to revise them one-stage. Results In 8 cases the reconstruction was performed with an articulating prosthetic joint (3 proximal femur and 5 knee megaprosthesis of the distal femur) and in 2 cases with a knee arthrodesis prosthesis. Monitoring of inflammatory markers (ESR, C-reactive protein, fibrinogen) showed resolution of the infection in all cases. Discussion From the clinical point of view, all patients were satisfied with surgery. Radiographically, there are no signs of loosening or periprosthetic bone resorption. Conclusions the preliminary results of such a limited group of patients are encouraging and demonstrate that the use of silver coating prosthesis may be indicated in the reconstructions of periarticular loss of substance in septic failures, making single-stage revision surgery safer

Percutaneous repair of acute Achilles tendon rupture: A 10-year follow-up

Aim. The incidence of Achilles tendon ruptures is constantly improving, probably as a result of the increment of recreational sport activities. Percutaneous tendon repair, described for the first time in 1977 by Ma and Griffith, minimize many of complications that accompany open surgical repairs and combine the advantages of surgical and non surgical management. Currently this technique has increasing popularity and is considered safe and effective in repairing ruptured Achilles tendon. We use this procedure, modified, from 1997 and the purpose of this study is the evaluation of long term results of first 20 cases operated between 1997 and 1999. Methods. At follow-up the controls patients had been evaluated subjectively with a questionnaire and clinically with a sensory assessment, measurement of calf circumference, ankle range of motion and a stress test with the patient on bilateral and unilateral tip toe. Moreover we performed bilateral ultrasonography examinations to control tendon healing and size and MRI evaluation for a more accurate study of tendon structure and thickness. Results. The overall results were good. No re-ruptures. We confirm an increase of Achilles tendon thickness without structural impairments. Conclusion. At long-term follow-up percutaneous repair proved a simple, safe, reliable, low cost procedure with a high patient's compliance