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BACKGROUND AND OBJECTIVE: In everyday clinical practice, medical decision is currently based on clinical guidelines which are often static and rigid, and do not account for population variability, while individualized, patient-oriented decision and/or treatment are the paradigm change necessary to enter into the era of precision medicine. Most of the limitations of a guideline-based system could be overcome through the adoption of Clinical Decision Support Systems (CDSSs) based on Artificial Intelligence (AI) algorithms. However, the black-box nature of AI algorithms has hampered a large adoption of AI-based CDSSs in clinical practice. In this study, an innovative AI-based method to compress AI-based prediction models into explainable, model-agnostic, and reduced decision support systems (NEAR) with application to healthcare is presented and validated. METHODS: NEAR is based on the Shapley Additive Explanations framework and can be applied to complex input models to obtain the contributions of each input feature to the output. Technically, the simplified NEAR models approximate contributions from input features using a custom library and merge them to determine the final output. Finally, NEAR estimates the confidence error associated with the single input feature contributing to the final score, making the result more interpretable. Here, NEAR is evaluated on a clinical real-world use case, the mortality prediction in patients who experienced Acute Coronary Syndrome (ACS), applying three different Machine Learning/Deep Learning models as implementation examples. RESULTS: NEAR, when applied to the ACS use case, exhibits performances like the ones of the AI-based model from which it is derived, as in the case of the Adaptive Boosting classifier, whose Area Under the Curve is not statistically different from the NEAR one, even the model's simplification. Moreover, NEAR comes with intrinsic explainability and modularity, as it can be tested on the developed web application platform (https://neardashboard.pythonanywhere.com/). CONCLUSIONS: An explainable and reliable CDSS tailored to single-patient analysis has been developed. The proposed AI-based system has the potential to be used alongside the clinical guidelines currently employed in the medical setting making them more personalized and dynamic and assisting doctors in taking their everyday clinical decisions.
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Algoritmos , Inteligencia Artificial , Sistemas de Apoyo a Decisiones Clínicas , Sistemas de Apoyo a Decisiones Clínicas/organización & administración , HumanosRESUMEN
BACKGROUND: This study assessed the efficacy, tolerability and pharmacokinetics (PK) of lanthanum carbonate (LC) in hyperphosphatemic children and adolescents with chronic kidney disease (CKD) undergoing dialysis. METHODS: This was a three-part, multicenter, open-label study of LC (oral powder formulation) in patients 10 to < 18 years old with CKD undergoing dialysis. In part 1, the single-dose PK of LC (500 mg, ≤12 years old; 1000 mg, > 12 years old) were summarized. In part 2, patients received calcium carbonate (CC [chewable tablet formulation]) (1500-6500 mg [total daily dose]) followed by LC (powder formulation) (1500-3000 mg [total daily dose]), or LC only (1500-3000 mg [total daily dose]), each for 8 weeks. During part 3, patients received LC (1500-3000 mg [total daily dose]) for up to 6 months. The primary efficacy endpoint was the proportion of LC-treated patients achieving serum phosphorus control after 8 weeks during parts 2 and/or 3, defined as: ≤1.94 mmol/L, < 12 years old; ≤1.78 mmol/L, ≥12 years old. Secondary efficacy endpoints included: the proportion of patients who achieved serum phosphorus control after 8 weeks of treatment with CC followed by 8 weeks of treatment with LC (with a washout period between treatments). The safety of LC and CC was also evaluated. RESULTS: In part 1, 20 patients received a single dose of LC. In part 2, 53 and 51 patients were treated with CC and LC for 8 weeks, respectively. During part 3, 42 patients received LC for up to 6 months. Most patients were white and male. For the primary efficacy endpoint, 50% (17/34) of patients who received LC for 8 weeks during parts 2 and/or 3 achieved serum phosphorus control. After 8 weeks of treatment with CC, 58.8% of patients achieved serum phosphorus control; after a subsequent washout period and 8 weeks of treatment with LC, 70.6% of patients achieved serum phosphorus control. Tmax and t1/2 occurred within 3-8 h and ~ 19 h, respectively; however, variability was observed. LC and CC were generally well tolerated. CONCLUSIONS: These data support the use of LC to manage hyperphosphatemia in pediatric patients with CKD undergoing dialysis. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01696279; EudraCT identifier: 2012-000171-17. Date of registration: 01/10/2012.
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Hiperfosfatemia/tratamiento farmacológico , Hiperfosfatemia/etiología , Lantano/farmacocinética , Lantano/uso terapéutico , Diálisis Renal , Insuficiencia Renal Crónica/complicaciones , Insuficiencia Renal Crónica/terapia , Adolescente , Niño , Femenino , Humanos , Masculino , Resultado del TratamientoRESUMEN
AIMS/HYPOTHESIS: Inflammation has a major role in diabetic kidney disease. We thus investigated the role of the IL-8-CXCR1/2 axis in favoring kidney damage in diabetes. METHODS: Urinary IL-8 levels were measured in 1247 patients of the Joslin Kidney Study in type 2 diabetes (T2D). The expression of IL-8 and of its membrane receptors CXCR1/CXCR2 was quantified in kidney tissues in patients with T2D and in controls. The effect of CXCR1/2 blockade on diabetic kidney disease was evaluated in db/db mice. RESULTS: IL-8 urinary levels were increased in patients with T2D and diabetic kidney disease, with the highest urinary IL-8 levels found in the patients with the largest decline in glomerular filtration rate, with an increased albumin/creatine ratio and the worst renal outcome. Moreover, glomerular IL-8 renal expression was increased in patients with T2D, as compared to controls. High glucose elicits abundant IL-8 secretion in cultured human immortalized podocytes in vitro. Finally, in diabetic db/db mice and in podocytes in vitro, CXCR1/2 blockade mitigated albuminuria, reduced mesangial expansion, decreased podocyte apoptosis and reduced DNA damage. CONCLUSIONS/INTERPRETATION: The IL-8- CXCR1/2 axis may have a role in diabetic kidney disease by inducing podocyte damage. Indeed, targeting the IL-8-CXCR1/2 axis may reduce the burden of diabetic kidney disease.
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Nefropatías Diabéticas/genética , Interleucina-8/fisiología , Receptores CXCR/fisiología , Adulto , Animales , Estudios de Casos y Controles , Células Cultivadas , Estudios de Cohortes , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patología , Nefropatías Diabéticas/metabolismo , Nefropatías Diabéticas/patología , Humanos , Interleucina-8/genética , Interleucina-8/metabolismo , Italia , Riñón/metabolismo , Riñón/patología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Podocitos/metabolismo , Podocitos/patología , Receptores de Interleucina-8A/genética , Receptores de Interleucina-8A/metabolismo , Receptores de Interleucina-8B/genética , Receptores de Interleucina-8B/metabolismo , Transducción de Señal/fisiologíaRESUMEN
Despite much progress in improving graft outcome during cardiac transplantation, chronic allograft vasculopathy (CAV) remains an impediment to long-term graft survival. MicroRNAs (miRNAs) emerged as regulators of the immune response. Here, we aimed to examine the miRNA network involved in CAV. miRNA profiling of heart samples obtained from a murine model of CAV and from cardiac-transplanted patients with CAV demonstrated that miR-21 was most significantly expressed and was primarily localized to macrophages. Interestingly, macrophage depletion with clodronate did not significantly prolong allograft survival in mice, while conditional deletion of miR-21 in macrophages or the use of a specific miR-21 antagomir resulted in indefinite cardiac allograft survival and abrogated CAV. The immunophenotype, secretome, ability to phagocytose, migration, and antigen presentation of macrophages were unaffected by miR-21 targeting, while macrophage metabolism was reprogrammed, with a shift toward oxidative phosphorylation in naïve macrophages and with an inhibition of glycolysis in pro-inflammatory macrophages. The aforementioned effects resulted in an increase in M2-like macrophages, which could be reverted by the addition of L-arginine. RNA-seq analysis confirmed alterations in arginase-associated pathways associated with miR-21 antagonism. In conclusion, miR-21 is overexpressed in murine and human CAV, and its targeting delays CAV onset by reprogramming macrophages metabolism.
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Trasplante de Corazón , MicroARNs , Aloinjertos , Animales , Rechazo de Injerto/genética , Rechazo de Injerto/prevención & control , Trasplante de Corazón/efectos adversos , Humanos , Macrófagos , Ratones , MicroARNs/genéticaRESUMEN
BACKGROUND/AIMS: This post-marketing observational study assessed the long-term safety of lanthanum carbonate (LaC) in US patients with end-stage renal disease (NCT00567723). METHODS: Patients (≥18 years old) undergoing dialysis, who had Medicare as their primary healthcare payer, and records in the United States Renal Data System were followed-up for 5 years. Patients who had received LaC for at least 12 consecutive weeks formed the exposed cohort. During the same time period, patients who had undergone dialysis for at least 12 consecutive weeks and had been treated with any other phosphate binder formed the primary comparator cohort. A historical cohort was also evaluated. Primary outcomes were all-cause mortality, and time to and incidence of first bone-fracture event requiring hospitalization. Secondary outcomes were time to first occurrence of and incidence of specific gastrointestinal (GI) disease, liver disease, malignancy, and major infectious episode requiring hospitalization. -Results: 2,026 and 8,094 patients were included in the exposed and primary comparator cohorts, respectively. A Cox proportional hazards model showed that patients receiving LaC were not at increased risk of all-cause mortality (adjusted hazard ratio 0.94; 95% CI 0.88-1.01; p = 0.078), bone fractures (0.86; 0.71-1.05; p = 0.130), specific GI disease (0.86; 0.76-0.97; p = 0.015), liver disease (0.88; 0.70-1.09; p = 0.236), malignancy (0.85; 0.54-1.34; p = 0.496), or major infectious episodes (0.87; 0.80-0.94; p < 0.001) requiring hospitalization compared with primary comparator patients. CONCLUSIONS: LaC was not associated with increased risk of mortality, bone fractures, or any secondary outcome.
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Huesos/patología , Fallo Renal Crónico/tratamiento farmacológico , Fallo Renal Crónico/mortalidad , Lantano/efectos adversos , Lantano/uso terapéutico , Fármacos Renales/efectos adversos , Fármacos Renales/uso terapéutico , Adulto , Anciano , Estudios de Cohortes , Femenino , Fracturas Óseas/epidemiología , Fracturas Óseas/prevención & control , Humanos , Estimación de Kaplan-Meier , Fallo Renal Crónico/patología , Masculino , Persona de Mediana Edad , Seguridad del Paciente , Diálisis Renal , Resultado del Tratamiento , Estados Unidos/epidemiologíaRESUMEN
Extracellular ATP (eATP) activates T cells by engaging the P2X7R receptor. We identified two loss-of-function P2X7R mutations that are protective against type 1 diabetes (T1D) and thus hypothesized that eATP/P2X7R signaling may represent an early step in T1D onset. Specifically, we observed that in patients with newly diagnosed T1D, P2X7R is upregulated on CD8+ effector T cells in comparison with healthy control subjects. eATP is released at high levels by human/murine islets in vitro in high-glucose/inflammatory conditions, thus upregulating P2X7R on CD8+ T cells in vitro. P2X7R blockade with oxidized ATP reduces the CD8+ T cell-mediated autoimmune response in vitro and delays diabetes onset in NOD mice. Autoreactive CD8+ T-cell activation is highly dependent upon eATP/P2X7R-mediated priming, while a novel sP2X7R recombinant protein abrogates changes in metabolism and the autoimmune response associated with CD8+ T cells. eATP/P2X7R signaling facilitates the onset of autoimmune T1D by fueling autoreactive CD8+ cells and therefore represents a novel targeted therapeutic for the disorder.
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Adenosina Trifosfato/metabolismo , Linfocitos T CD8-positivos/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Adenosina Trifosfato/análogos & derivados , Adenosina Trifosfato/farmacología , Animales , Autoinmunidad/genética , Autoinmunidad/fisiología , Diabetes Mellitus Tipo 1/genética , Femenino , Citometría de Flujo , Humanos , Activación de Linfocitos/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos NOD , Mutación/genética , Receptores Purinérgicos P2X7/genéticaRESUMEN
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.
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Rechazo de Injerto/inmunología , Trasplante de Corazón , Mutación , Proteína con Dominio Pirina 3 de la Familia NLR/inmunología , Receptores Purinérgicos P2X7/inmunología , Células Th17/inmunología , Células Th2/inmunología , Aloinjertos , Femenino , Rechazo de Injerto/genética , Rechazo de Injerto/patología , Rechazo de Injerto/terapia , Humanos , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Medicina de Precisión , Receptores Purinérgicos P2X7/genética , Células Th17/patología , Células Th2/patologíaRESUMEN
The role of circulating factors in regulating colonic stem cells (CoSCs) and colonic epithelial homeostasis is unclear. Individuals with long-standing type 1 diabetes (T1D) frequently have intestinal symptoms, termed diabetic enteropathy (DE), though its etiology is unknown. Here, we report that T1D patients with DE exhibit abnormalities in their intestinal mucosa and CoSCs, which fail to generate in vitro mini-guts. Proteomic profiling of T1D+DE patient serum revealed altered levels of insulin-like growth factor 1 (IGF-I) and its binding protein 3 (IGFBP3). IGFBP3 prevented in vitro growth of patient-derived organoids via binding its receptor TMEM219, in an IGF-I-independent manner, and disrupted in vivo CoSC function in a preclinical DE model. Restoration of normoglycemia in patients with long-standing T1D via kidney-pancreas transplantation or in diabetic mice by treatment with an ecto-TMEM219 recombinant protein normalized circulating IGF-I/IGFBP3 levels and reestablished CoSC homeostasis. These findings demonstrate that peripheral IGF-I/IGFBP3 controls CoSCs and their dysfunction in DE.
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Colon/citología , Complicaciones de la Diabetes/patología , Diabetes Mellitus Experimental/patología , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Factor I del Crecimiento Similar a la Insulina/metabolismo , Células Madre/fisiología , Animales , Colon/fisiología , Complicaciones de la Diabetes/metabolismo , Diabetes Mellitus Experimental/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Proteínas de la Membrana/metabolismo , Ratones , ProteómicaRESUMEN
AIMS: Mesenchymal stem cells (MSCs) are multipotent cells with immunomodulatory properties. We tested the ability of MSCs to delay islet allograft rejection. METHODS: Mesenchymal stem cells were generated in vitro from C57BL/6 and BALB/c mice bone marrow, and their immunomodulatory properties were tested in vitro. We then tested the effect of a local or systemic administration of heterologous and autologous MSCs on graft survival in a fully allogeneic model of islet transplantation (BALB/c islets into C57BL/6 mice). RESULTS: In vitro, autologous, but not heterologous, MSCs abrogated immune cell proliferation in response to alloantigens and skewed the immune response toward a Th2 profile. A single dose of autologous MSCs co-transplanted under the kidney capsule with allogeneic islets delayed islet rejection, reduced graft infiltration, and induced long-term graft function in 30 % of recipients. Based on ex vivo analysis of recipient splenocytes, the use of autologous MSCs did not appear to have any systemic effect on the immune response toward graft alloantigens. The systemic injection of autologous MSCs or the local injection of heterologous MSCs failed to delay islet graft rejection. CONCLUSION: Autologous, but not heterologous, MSCs showed multiple immunoregulatory properties in vitro and delayed allograft rejection in vivo when co-transplanted with islets; however, they failed to prevent rejection when injected systemically. Autologous MSCs thus appear to produce a local immunoprivileged site, which promotes graft survival.
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Rechazo de Injerto/prevención & control , Trasplante de Islotes Pancreáticos/métodos , Trasplante de Células Madre Mesenquimatosas/métodos , Animales , Células de la Médula Ósea/inmunología , Trasplante de Médula Ósea/métodos , Proliferación Celular , Citocinas/metabolismo , Rechazo de Injerto/inmunología , Supervivencia de Injerto , Prueba de Cultivo Mixto de Linfocitos , Células Madre Mesenquimatosas/inmunología , Células Madre Mesenquimatosas/ultraestructura , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Bazo/citología , Células Th17/inmunologíaRESUMEN
Age is a major risk factor in age-related macular degeneration (AMD), but the underlying cause is unknown. We find increased Rho-associated kinase (ROCK) signaling and M2 characteristics in eyes of aged mice, revealing immune changes in aging. ROCK isoforms determine macrophage polarization into M1 and M2 subtypes. M2-like macrophages accumulated in AMD, but not in normal eyes, suggesting that these macrophages may be linked to macular degeneration. M2 macrophages injected into the mouse eye exacerbated choroidal neovascular lesions, while M1 macrophages ameliorated them, supporting a causal role for macrophage subtypes in AMD. Selective ROCK2 inhibition with a small molecule decreased M2-like macrophages and choroidal neovascularization. ROCK2 inhibition upregulated M1 markers without affecting macrophage recruitment, underlining the plasticity of these macrophages. These results reveal age-induced innate immune imbalance as underlying AMD pathogenesis. Targeting macrophage plasticity opens up new possibilities for more effective AMD treatment.
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Macrófagos/metabolismo , Quinasas Asociadas a rho/metabolismo , Envejecimiento , Animales , Células de la Médula Ósea/citología , Diferenciación Celular/efectos de los fármacos , Polaridad Celular , Células Cultivadas , Coroides/irrigación sanguínea , Neovascularización Coroidal , Citocinas/farmacología , Humanos , Macrófagos/citología , Degeneración Macular/metabolismo , Degeneración Macular/patología , Masculino , Ratones , Ratones Endogámicos C57BL , FN-kappa B/metabolismo , Transducción de Señal , Quinasas Asociadas a rho/antagonistas & inhibidoresRESUMEN
Diabetes is a metabolic disorder characterized by elevation of glucose levels in the blood that develops in humans as a result of genetic predisposition and environmental factors. Unbalanced glycemic control has been associated with the development of progressive and debilitating complications that dramatically affect the quality of life and life expectancy of people with diabetes. The purinergic system represents a widely diffused signaling pathway in mammalian cells of different tissues where it plays critical roles in both physiological and pathological conditions. Herein we review the increasing evidence supporting that the purinergic system plays an important role in the multiple facets of diabetes, including its physiopathology and complications. We also discuss the potential relevance of the purinergic pathway for diagnosis and treatment of diabetes.
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Diabetes Mellitus/metabolismo , Receptores Purinérgicos P2X/metabolismo , Animales , Humanos , Transducción de SeñalRESUMEN
The role of the novel costimulatory molecule TIM4 in anti-islet response is unknown. We explored TIM4 expression and targeting in Th1 (BALB/c islets into C57BL/6 mice) and Th2 (BALB/c islets into Tbet(-/-) C57BL/6 mice) models of anti-islet alloimmune response and in a model of anti-islet autoimmune response (diabetes onset in NOD mice). The targeting of TIM4, using the monoclonal antibody RMT4-53, promotes islet graft survival in a Th1 model, with 30% of the graft surviving in the long term; islet graft protection appears to be mediated by a Th1 to Th2 skewing of the immune response. Differently, in the Th2 model, TIM4 targeting precipitates graft rejection by further enhancing the Th2 response. The effect of anti-TIM4 treatment in preventing autoimmune diabetes was marginal with only minor Th1 to Th2 skewing. B-Cell depletion abolished the effect of TIM4 targeting. TIM4 is expressed on human B-cells and is upregulated in diabetic and islet-transplanted patients. Our data suggest a model in which TIM4 targeting promotes Th2 response over Th1 via B-cells. The targeting of TIM4 could become a component of an immunoregulatory protocol in clinical islet transplantation, aiming at redirecting the immune system toward a Th2 response.
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Autoinmunidad , Trasplante de Islotes Pancreáticos/inmunología , Proteínas de la Membrana/metabolismo , Células Th2/inmunología , Adulto , Animales , Linfocitos B/citología , Linfocitos B/inmunología , Linfocitos B/metabolismo , Diferenciación Celular , Citocinas/análisis , Citocinas/metabolismo , Diabetes Mellitus Experimental/mortalidad , Diabetes Mellitus Experimental/cirugía , Diabetes Mellitus Tipo 1/cirugía , Femenino , Supervivencia de Injerto/inmunología , Humanos , Islotes Pancreáticos/patología , Masculino , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Persona de Mediana Edad , Tasa de Supervivencia , Células TH1/citología , Células TH1/inmunología , Células TH1/metabolismo , Células Th2/citología , Células Th2/metabolismo , Transcriptoma , Trasplante HomólogoRESUMEN
Impaired regulatory B cell (Breg) responses are associated with several autoimmune diseases in humans; however, the role of Bregs in type 1 diabetes (T1D) remains unclear. We hypothesized that naturally occurring, interleukin-10 (IL-10)-producing Bregs maintain tolerance to islet autoantigens, and that hyperglycemic nonobese diabetic (NOD) mice and T1D patients lack these potent negative regulators. IgVH transcriptome analysis revealed that islet-infiltrating B cells in long-term normoglycemic (Lnglc) NOD, which are naturally protected from diabetes, are more antigen-experienced and possess more diverse B-cell receptor repertoires compared to those of hyperglycemic (Hglc) mice. Importantly, increased levels of Breg-promoting CD40(+) B cells and IL-10-producing B cells were found within islets of Lnglc compared to Hglc NOD. Likewise, healthy individuals showed increased frequencies of both CD40(+) and IL-10(+) B cells compared to T1D patients. Rituximab-mediated B-cell depletion followed by adoptive transfer of B cells from Hglc mice induced hyperglycemia in Lnglc human CD20 transgenic NOD mouse models. Importantly, both murine and human IL-10(+) B cells significantly abrogated T-cell-mediated responses to self- or islet-specific peptides ex vivo. Together, our data suggest that antigen-matured Bregs may maintain tolerance to islet autoantigens by selectively suppressing autoreactive T-cell responses, and that Hglc mice and individuals with T1D lack this population of Bregs.
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Linfocitos B Reguladores/inmunología , Antígenos CD40/inmunología , Diabetes Mellitus Tipo 1/inmunología , Tolerancia Inmunológica/inmunología , Interleucina-10/inmunología , Islotes Pancreáticos/inmunología , Adulto , Animales , Autoantígenos/genética , Autoantígenos/inmunología , Linfocitos B Reguladores/metabolismo , Antígenos CD40/metabolismo , Femenino , Humanos , Interleucina-10/metabolismo , Masculino , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Ratones SCID , Ratones Transgénicos , Persona de Mediana Edad , Transcriptoma/inmunología , Adulto JovenRESUMEN
Islet transplantation has been demonstrated to improve glycometabolic control, to reduce hypoglycemic episodes and to halt the progression of diabetic complications. However, the exhaustion of islet function and the side effects related to chronic immunosuppression limit the spread of this technique. Consequently, new immunoregulatory protocols have been developed, with the aim to avoid the use of a life-time immunosuppression. Several approaches have been tested in preclinical models, and some are now under clinical evaluation. The development of new small molecules and new monoclonal or polyclonal antibodies is continuous and raises the possibility of targeting new costimulatory pathways or depleting particular cell types. The use of stem cells and regulatory T cells is underway to take advantage of their immunological properties and to induce tolerance. Xenograft islet transplantation, although having severe problems in terms of immunological compatibility, could theoretically provide an unlimited source of donors; using pigs carrying human immune antigens has showed indeed promising results. A completely different approach, the use of encapsulated islets, has been developed; synthetic structures are used to hide islet alloantigen from the immune system, thus preserving islet endocrine function. Once one of these strategies is demonstrated safe and effective, it will be possible to establish clinical islet transplantation as a treatment for patients with type 1 diabetes long before the onset of diabetic-related complications.
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Terapia de Inmunosupresión/métodos , Inmunosupresores/uso terapéutico , Trasplante de Islotes Pancreáticos/inmunología , Trasplante de Islotes Pancreáticos/métodos , Animales , Diabetes Mellitus Tipo 1/terapia , Xenoinjertos , Humanos , Porcinos , Trasplante AutólogoRESUMEN
Ischemia/reperfusion (I/R) is one of the most common causes of acute kidney injury. Reactive oxygen species have been recognized to be an important contributor to the pathogenesis of I/R injury. We hypothesize that a non-peptidyl low molecular weight radical scavenger (IAC) therapy may counteract this factor, ultimately providing some protection after acute phase renal I/R injury. The aim of this preliminary study was to assess the ability of IAC to reduce acute kidney injury in C57BL/6 mice after 30-minute of bilateral ischemia followed by reperfusion. The rise in serum creatinine level was higher in C57BL/6 control mice after I/R when compared to IAC (1 mg)-treated mice. Control mice showed greater body weight loss compared to IAC-treated mice, and at pathology, reduced signs of tubular necrosis were also evident in IAC-treated mice. These preliminary evidences lay the basis for more comprehensive studies on the positive effects of IAC as a complementary therapeutic approach for acute phase renal I/R injury.
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Podocyte injury and resulting albuminuria are hallmarks of diabetic nephropathy, but targeted therapies to halt or prevent these complications are currently not available. Here, we show that the immune-related molecule B7-1/CD80 is a critical mediator of podocyte injury in type 2 diabetic nephropathy. We report the induction of podocyte B7-1 in kidney biopsy specimens from patients with type 2 diabetes. Genetic and epidemiologic studies revealed the association of two single nucleotide polymorphisms at the B7-1 gene with diabetic nephropathy. Furthermore, increased levels of the soluble isoform of the B7-1 ligand CD28 correlated with the progression to ESRD in individuals with type 2 diabetes. In vitro, high glucose conditions prompted the phosphatidylinositol 3 kinase-dependent upregulation of B7-1 in podocytes, and the ectopic expression of B7-1 in podocytes increased apoptosis and induced disruption of the cytoskeleton that were reversed by the B7-1 inhibitor CTLA4-Ig. Podocyte expression of B7-1 was also induced in vivo in two murine models of diabetic nephropathy, and treatment with CTLA4-Ig prevented increased urinary albumin excretion and improved kidney pathology in these animals. Taken together, these results identify B7-1 inhibition as a potential therapeutic strategy for the prevention or treatment of diabetic nephropathy.
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Antígeno B7-1/fisiología , Diabetes Mellitus Tipo 1/complicaciones , Nefropatías Diabéticas/etiología , Podocitos , Adulto , Anciano , Animales , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Regulación hacia ArribaRESUMEN
Lung transplantation has limited survival with current immunosuppression. ATP is released from activated T cells, which act as costimulatory molecules through binding to the purinergic receptor P2XR7. We investigated the role of blocking the ATP/purinergic pathway, primarily P2XR7, using its inhibitor oxidized ATP (oATP) in modulating rejection of mouse lung allografts. Mouse lung transplants were performed using mice with major histocompatibility complex mismatch, BALB/c to C57BL6. Recipients received suramin or oATP, and lung allografts were evaluated 15 to ≥ 60 days after transplantation. Recipients were also treated with oATP after the onset of moderate to severe rejection to determine its ability to rescue lung allografts. Outcomes measures included lung function, histology, thoracic imaging, and allo-immune responses. Blocking purinergic receptors with the nonselective inhibitor suramin or with the P2XR7-selective inhibitor oATP reduced acute rejection and prolonged lung allograft survival for ≥ 60 days with no progression in severity. There were fewer inflammatory cells within lung allografts, less rejection, and improved lung function, which was maintained over time. CD4 and CD8 T cells were reduced within lung allografts with impaired activation with prolonged impairment of CD8 responses. In vitro, oATP reduced CD8 activation of Th1 inflammatory cytokines IFN-γ and TNF-α and cytolytic machinery, granzyme B. Cotreatment with immunosuppressive agents, cyclosporine, rapamycin, or CTLA-4Ig resulted in no additive benefits, and oATP alone resulted in better outcomes than cyclosporine alone. This study illustrates a potential new pathway to target in hopes of prolonging survival of lung transplant recipients.
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Adenosina Trifosfato/análogos & derivados , Rechazo de Injerto/prevención & control , Supervivencia de Injerto/efectos de los fármacos , Inmunosupresores/farmacología , Trasplante de Pulmón/efectos adversos , Pulmón/efectos de los fármacos , Antagonistas del Receptor Purinérgico P2X/farmacología , Receptores Purinérgicos P2X7/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Suramina/farmacología , Adenosina Trifosfato/farmacología , Aloinjertos , Animales , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Rechazo de Injerto/inmunología , Rechazo de Injerto/metabolismo , Rechazo de Injerto/patología , Histocompatibilidad , Pulmón/inmunología , Pulmón/metabolismo , Pulmón/patología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Receptores Purinérgicos P2X7/metabolismo , Factores de TiempoRESUMEN
OBJECTIVE Islets after kidney transplantation have been shown to positively affect the quality of life of individuals with type 1 diabetes (T1D) by reducing the burden of diabetes complications, but fewer data are available for islet transplantation alone (ITA). The aim of this study was to assess whether ITA has a positive impact on hemostatic and cerebral abnormalities in individuals with T1D. RESEARCH DESIGN AND METHODS Prothrombotic factors, platelet function/ultrastructure, and cerebral morphology, metabolism, and function have been investigated over a 15-month follow-up period using ELISA/electron microscopy and magnetic resonance imaging, nuclear magnetic resonance spectroscopy, and neuropsychological evaluation (Profile of Mood States test and paced auditory serial addition test) in 22 individuals with T1D who underwent ITA (n = 12) or remained on the waiting list (n = 10). Patients were homogeneous with regard to metabolic criteria, hemostatic parameters, and cerebral morphology/metabolism/function at the time of enrollment on the waiting list. RESULTS At the 15-month follow-up, the group undergoing ITA, but not individuals with T1D who remained on the waiting list, showed 1) improved glucose metabolism; 2) near-normal platelet activation and prothrombotic factor levels; 3) near-normal cerebral metabolism and function; and 4) a near-normal neuropsychological test. CONCLUSIONS ITA, despite immunosuppressive therapy, is associated with a near-normalization of hemostatic and cerebral abnormalities.
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Encéfalo/fisiopatología , Diabetes Mellitus Tipo 1/fisiopatología , Diabetes Mellitus Tipo 1/cirugía , Hemostasis , Trasplante de Islotes Pancreáticos , Adulto , Glucemia/metabolismo , Plaquetas/patología , Plaquetas/fisiología , Encéfalo/metabolismo , Encéfalo/patología , Diabetes Mellitus Tipo 1/patología , Diabetes Mellitus Tipo 1/psicología , Femenino , Humanos , Inmunosupresores/uso terapéutico , Masculino , Proyectos Piloto , Calidad de Vida , Estudios RetrospectivosRESUMEN
In a successful pregnancy, the semiallogeneic fetus is not rejected by the maternal immune system, which implies tolerance mechanisms protecting fetal tissues from maternal immune attack. Here we report that the ICOS-B7h costimulatory pathway plays a critical role in maintaining the equilibrium at the fetomaternal interface. Blockade of this pathway increased fetal resorption and decreased fetal survival in an allogeneic pregnancy model (CBA female × B6 male). Locally in the placenta, levels of regulatory markers such as IDO and TGF-ß1 were reduced after anti-B7h monoclonal antibody treatment, whereas levels of effector cytokines (eg, IFN-γ) were significantly increased. In secondary lymphoid organs, enhanced IFN-γ and granzyme B production (predominantly by CD8(+) T cells) was observed in the anti-B7h-treated group. The deleterious effect of B7h blockade in pregnancy was maintained only in CD4 knockout mice, not in CD8 knockout mice, which suggests a role for CD8(+) T cells in immune regulation by the ICOS-B7h pathway. In accord, regulatory CD8(+) T cells (in particular, CD8(+)CD103(+) cells) were significantly decreased after anti-B7h monoclonal antibody treatment, and adoptive transfer of this subset abrogated the deleterious effect of B7h blockade in fetomaternal tolerance. Taken together, these data support the hypothesis that B7h blockade abrogates tolerance at the fetomaternal interface by enhancing CD8(+) effector response and reducing local immunomodulation mediated by CD8(+) regulatory T cells.
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Tolerancia Inmunológica/inmunología , Ligando Coestimulador de Linfocitos T Inducibles/inmunología , Intercambio Materno-Fetal/inmunología , Placenta/inmunología , Traslado Adoptivo , Animales , Anticuerpos Monoclonales/inmunología , Linfocitos T CD8-positivos/inmunología , Antígeno CTLA-4/inmunología , Citocinas/biosíntesis , Pérdida del Embrión/inmunología , Femenino , Indolamina-Pirrol 2,3,-Dioxigenasa/inmunología , Ligando Coestimulador de Linfocitos T Inducibles/antagonistas & inhibidores , Tamaño de la Camada/inmunología , Ganglios Linfáticos/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Ratones Noqueados , Embarazo , Bazo/inmunología , Subgrupos de Linfocitos T/inmunología , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/trasplanteRESUMEN
CD160 is a cell surface molecule expressed by most NK cells and approximately 50% of CD8(+) cytotoxic T lymphocytes. Engagement of CD160 by MHC class-I directly triggers a costimulatory signal to TCR-induced proliferation, cytokine production and cytotoxic effector functions. The role of CD160 in alloimmunity is unknown. Using a newly generated CD160 fusion protein (CD160Ig) we examined the role of the novel costimulatory molecule CD160 in mediating CD4(+) or CD8(+) T cell driven allograft rejection. CD160Ig inhibits alloreactive CD8(+) T cell proliferation and IFN-γ production in vitro, in particular in the absence of CD28 costimulation. Consequently CD160Ig prolongs fully mismatched cardiac allograft survival in CD4(-/-), CD28(-/-) knockout and CTLA4Ig treated WT recipients, but not in WT or CD8(-/-) knockout recipients. The prolonged cardiac allograft survival is associated with reduced alloreactive CD8(+) T cell proliferation, effector/memory responses and alloreactive IFN-γ production. Thus, CD160 signaling is particularly important in CD28-independent effector/memory CD8(+) alloreactive T cell activation in vivo and therefore may serve as a novel target for prevention of allograft rejection.