RESUMO
We have recently developed a model of pancreatic islet transplantation into a decellularized pancreatic tail in rats. As the pancreatic skeletons completely lack endothelial cells, we investigated the effect of co-transplantation of mesenchymal stem cells and endothelial cells to promote revascularization. Decellularized matrix of the pancreatic tail was prepared by perfusion with Triton X-100, sodium dodecyl sulfate and DNase solution. Isolated pancreatic islets were infused into the skeletons via the splenic vein either alone, together with adipose tissue-derived mesenchymal stem cells (adMSCs), or with a combination of adMSCs and rat endothelial cells (rat ECs). Repopulated skeletons were transplanted into the subcutaneous tissue and explanted 9 days later for histological examination. Possible immunomodulatory effects of rat adMSCs on the survival of highly immunogenic green protein-expressing human ECs were also tested after their transplantation beneath the renal capsule. The immunomodulatory effects of adMSCs were also tested in vitro using the Invitrogen Click-iT EdU system. In the presence of adMSCs, the proliferation of splenocytes as a response to phytohaemagglutinin A was reduced by 47% (the stimulation index decreased from 1.7 to 0.9, P = 0.008) and the reaction to human ECs was reduced by 58% (the stimulation index decreased from 1.6 to 0.7, P = 0.03). Histological examination of the explanted skeletons seeded only with the islets showed their partial disintegration and only a rare presence of CD31-positive cells. However, skeletons seeded with a combination of islets and adMSCs showed preserved islet morphology and rich vascularity. In contrast, the addition of syngeneic rat ECs resulted in islet-cell necrosis with only few endothelial cells present. Live green fluorescence-positive endothelial cells transplanted either alone or with adMSCs were not detected beneath the renal capsule. Though the adMSCs significantly reduced in vitro proliferation stimulated by either phytohaemagglutinin A or by xenogeneic human ECs, in vivo co-transplanted adMSCs did not suppress the post-transplant immune response to xenogeneic ECs. Even in the syngeneic model, ECs co-transplantation did not lead to sufficient vascularization in the transplant area. In contrast, islet co-transplantation together with adMSCs successfully promoted the revascularization of extracellular matrix in the subcutaneous tissue.
Assuntos
Tecido Adiposo , Transplante das Ilhotas Pancreáticas , Ilhotas Pancreáticas , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Neovascularização Fisiológica , Animais , Ratos , Transplante das Ilhotas Pancreáticas/métodos , Humanos , Ilhotas Pancreáticas/imunologia , Transplante de Células-Tronco Mesenquimais/métodos , Tecido Adiposo/citologia , Masculino , Células Cultivadas , Células Endoteliais , Pâncreas , Matriz Extracelular DescelularizadaRESUMO
Objective: Beta cell destruction in type 1 diabetes (T1D) results from the combined effect of inflammation and recurrent autoimmunity. In recent years, the role played by beta cells in the development of T1D has evolved from passive victims of the immune system to active contributors in their own destruction. We and others have demonstrated that perturbations in the islet microenvironment promote endoplasmic reticulum (ER) stress in beta cells, leading to enhanced immunogenicity. Among the underlying mechanisms, secretion of extracellular vesicles (EVs) by beta cells has been suggested to mediate the crosstalk with the immune cell compartment. Methods: To study the role of cellular stress in the early events of T1D development, we generated a novel cellular model for constitutive ER stress by modulating the expression of HSPA5, which encodes BiP/GRP78, in EndoC-ßH1 cells. To investigate the role of EVs in the interaction between beta cells and the immune system, we characterized the EV miRNA cargo and evaluated their effect on innate immune cells. Results: Analysis of the transcriptome showed that HSPA5 knockdown resulted in the upregulation of signaling pathways involved in the unfolded protein response (UPR) and changes the miRNA content of EVs, including reduced levels of miRNAs involved in IL-1ß signaling. Treatment of primary human monocytes with EVs from stressed beta cells resulted in increased surface expression of CD11b, HLA-DR, CD40 and CD86 and upregulation of IL-1ß and IL-6. Conclusion: These findings indicate that the content of EVs derived from stressed beta cells can be a mediator of islet inflammation.
Assuntos
Chaperona BiP do Retículo Endoplasmático , Estresse do Retículo Endoplasmático , Vesículas Extracelulares , Células Secretoras de Insulina , MicroRNAs , Monócitos , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/imunologia , Monócitos/imunologia , Monócitos/metabolismo , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/imunologia , Humanos , Estresse do Retículo Endoplasmático/imunologia , MicroRNAs/genética , Inflamação/imunologia , Inflamação/metabolismo , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/metabolismo , Animais , Linhagem Celular , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/metabolismo , Transdução de Sinais , Resposta a Proteínas não Dobradas/imunologiaRESUMO
The aim of regenerative medicine is to restore specific functions to damaged cells or tissues. A crucial aspect of success lies in effectively reintegrating these cells or tissues within the recipient organism. This is particularly pertinent for diabetes, where islet function relies on the close connection of beta cells to the bloodstream for glucose sensing and insulin release. Central to this approach is the need to establish a fast connection with the host's vascular system. In this review, we explore the intricate relationships between endocrine, vascular, and immune cell interactions in transplantation outcomes. We also delve into recent strategies aimed at enhancing engraftment, along with the utilization of in vitro platforms to model cellular interactions.
Assuntos
Transplante das Ilhotas Pancreáticas , Ilhotas Pancreáticas , Humanos , Transplante das Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/citologia , Animais , Células Secretoras de Insulina/imunologia , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/citologia , Medicina Regenerativa , Diabetes Mellitus/imunologiaRESUMO
Regenerating family protein 2 (Reg2) is a trophic factor which stimulates ß-cell replication and resists islet destruction. However, Reg2 also serves as an islet autoantigen, which makes it complicated to judge the effectiveness in treating diabetes. How Reg2 treatment behaves in non-obese diabetic (NOD) mice is to be investigated. NOD mice were treated with recombinant Reg2 protein, Complete Freund's adjuvant (CFA) + PBS and CFA+Reg2 vaccinations, CFA+PBS- and CFA+Reg2-immunized antisera, and single chain variable fragment (scFv)-Reg2 and mIgG2a-Reg2 antibodies. Glycemic level, bodyweight, serum Reg2 antibody titer, glucose tolerance, and insulin secretion were determined. Islet morphological characteristics, insulitis, cell apoptosis, islet cell components, and T cell infiltration were analyzed by histological examinations. The autoantigenicity of constructed Reg2C and Reg2X fragments was determined in healthy BALB/c mice, and the bioactivity in stimulating cell proliferation and survival was assessed in insulinoma MIN6 cells. Reg2 administration alleviated diabetes in NOD mice with improved glucose tolerance and insulin secretion but elevated serum Reg2 autoantibodies. Histomorphometry showed reduced inflammatory area, TUNEL signal and CD8 + T cell infiltration, and increased ß-cell proportion in support of the islet-protective effect of Reg2 treatment. CFA+PBS and CFA+Reg2 immunizations prevented diabetic onset and alleviated insulitis while injections of the antisera offered mild protections. Antibody treatments accelerated diabetic onset without increasing the overall incidence. Reg2C fragment depletes antigenicity, but reserves protective activity in streptozotocin (STZ)-treated MIN6 cells. In conclusion, Reg2 treatment alleviates type 1 diabetes (T1D) by preserving islet ß-cells, but induces Reg2 autoantibody production which poses a potential risk of accelerating diabetic progression.
Assuntos
Autoanticorpos , Ilhotas Pancreáticas , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Proteínas Associadas a Pancreatite , Animais , Autoanticorpos/imunologia , Autoanticorpos/sangue , Camundongos , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/patologia , Feminino , Proteínas Associadas a Pancreatite/imunologia , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/prevenção & controle , Diabetes Mellitus Tipo 1/tratamento farmacológico , Litostatina/imunologiaRESUMO
AIMS/HYPOTHESIS: tRNAs play a central role in protein synthesis. Besides this canonical function, they were recently found to generate non-coding RNA fragments (tRFs) regulating different cellular activities. The aim of this study was to assess the involvement of tRFs in the crosstalk between immune cells and beta cells and to investigate their contribution to the development of type 1 diabetes. METHODS: Global profiling of the tRFs present in pancreatic islets of 4- and 8-week-old NOD mice and in extracellular vesicles released by activated CD4+ T lymphocytes was performed by small RNA-seq. Changes in the level of specific fragments were confirmed by quantitative PCR. The transfer of tRFs from immune cells to beta cells occurring during insulitis was assessed using an RNA-tagging approach. The functional role of tRFs increasing in beta cells during the initial phases of type 1 diabetes was determined by overexpressing them in dissociated islet cells and by determining the impact on gene expression and beta cell apoptosis. RESULTS: We found that the tRF pool was altered in the islets of NOD mice during the initial phases of type 1 diabetes. Part of these changes were triggered by prolonged exposure of beta cells to proinflammatory cytokines (IL-1ß, TNF-α and IFN-γ) while others resulted from the delivery of tRFs produced by CD4+ T lymphocytes infiltrating the islets. Indeed, we identified several tRFs that were enriched in extracellular vesicles from CD4+/CD25- T cells and were transferred to beta cells upon adoptive transfer of these immune cells in NOD.SCID mice. The tRFs delivered to beta cells during the autoimmune reaction triggered gene expression changes that affected the immune regulatory capacity of insulin-secreting cells and rendered the cells more prone to apoptosis. CONCLUSIONS/INTERPRETATION: Our data point to tRFs as novel players in the crosstalk between the immune system and insulin-secreting cells and suggest a potential involvement of this novel class of non-coding RNAs in type 1 diabetes pathogenesis. DATA AVAILABILITY: Sequences are available from the Gene Expression Omnibus (GEO) with accession numbers GSE242568 and GSE256343.
Assuntos
Diabetes Mellitus Tipo 1 , Células Secretoras de Insulina , Camundongos Endogâmicos NOD , RNA de Transferência , Animais , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/genética , Camundongos , Células Secretoras de Insulina/metabolismo , RNA de Transferência/genética , RNA de Transferência/metabolismo , Feminino , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/imunologia , Apoptose , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/imunologia , Vesículas Extracelulares/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismo , RNA não Traduzido/genéticaRESUMO
Autoreactive lymphocytes that infiltrate the pancreatic islet environment and target ß cells are primary drivers of type 1 diabetes. In this issue of Immunity, Srivastava et al.1 examine the role of the islet microenvironment in autoimmunity and find that the scavenging receptor CXCL16 on islet-resident macrophages uptakes oxidized low-density lipoproteins and promotes the differentiation and survival of infiltrating pathogenic CD8+ T cells.
Assuntos
Autoimunidade , Linfócitos T CD8-Positivos , Diabetes Mellitus Tipo 1 , Ilhotas Pancreáticas , Macrófagos , Autoimunidade/imunologia , Diabetes Mellitus Tipo 1/imunologia , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/metabolismo , Humanos , Animais , Macrófagos/imunologia , Macrófagos/metabolismo , Linfócitos T CD8-Positivos/imunologia , Células Secretoras de Insulina/imunologia , Células Secretoras de Insulina/metabolismo , Lipoproteínas LDL/metabolismo , Lipoproteínas LDL/imunologiaRESUMO
The 3 Screen ICA ELISA is a novel assay capable of simultaneously measuring autoantibodies to glutamic acid decarboxylase (GADA), insulinoma-associated antigen-2 (IA-2A), and zinc transporter 8 (ZnT8A), making it a valuable tool for screening type 1 diabetes. Despite its advantages, it cannot specify which individual autoantibodies are positive or negative. This study aimed to estimate individual positive autoantibodies based on the 3 Screen ICA titer. Six hundred seventeen patients with type 1 diabetes, simultaneously measured for 3 Screen ICA and three individual autoantibodies, were divided into five groups based on their 3 Screen ICA titer. The sensitivities and contribution rates of the individual autoantibodies were then examined. The study had a cross-sectional design. Sixty-nine percent (424 of 617) of patients with type 1 diabetes had 3 Screen ICA titers exceeding the 99th percentile cut-off level (20 index). The prevalence of GADA ranged from 80% to 100% in patients with a 3 Screen ICA over 30 index and 97% of patients with a 3 Screen ICA ≥300 index. Furthermore, the prevalence of all individual autoantibodies being positive was 0% for ≤80 index and as high as 92% for ≥300 index. Significant associations were observed in specific titer groups: the 20-29.9 index group when all the individual autoantibodies were negative, the 30-79.9 index group when positive for GADA alone or IA-2A alone, the 30-299.9 index group when positive for ZnT8A alone, the 80-299.9 index group when positive for both IA-2A and ZnT8A, the 300-499.9 index group when positive for both GADA and ZnT8A, and the ≥300 index group when positive for all individual autoantibodies. These results suggest that the 3 Screen ICA titer may be helpful in estimating individual positive autoantibodies.
Assuntos
Autoanticorpos , Diabetes Mellitus Tipo 1 , Glutamato Descarboxilase , Transportador 8 de Zinco , Humanos , Autoanticorpos/sangue , Autoanticorpos/imunologia , Masculino , Feminino , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/diagnóstico , Adulto , Transportador 8 de Zinco/imunologia , Glutamato Descarboxilase/imunologia , Estudos Transversais , Adolescente , Pessoa de Meia-Idade , Ensaio de Imunoadsorção Enzimática/métodos , Ilhotas Pancreáticas/imunologia , Adulto Jovem , Proteínas Tirosina Fosfatases Classe 8 Semelhantes a Receptores/imunologia , CriançaRESUMO
Human regulatory T cells (Treg) suppress other immune cells. Their dysfunction contributes to the pathophysiology of autoimmune diseases, including type 1 diabetes (T1D). Infusion of Tregs is being clinically evaluated as a novel way to prevent or treat T1D. Genetic modification of Tregs, most notably through the introduction of a chimeric antigen receptor (CAR) targeting Tregs to pancreatic islets, may improve their efficacy. We evaluated CAR targeting of human Tregs to monocytes, a human ß cell line and human islet ß cells in vitro. Targeting of HLA-A2-CAR (A2-CAR) bulk Tregs to HLA-A2+ cells resulted in dichotomous cytotoxic killing of human monocytes and islet ß cells. In exploring subsets and mechanisms that may explain this pattern, we found that CD39 expression segregated CAR Treg cytotoxicity. CAR Tregs from individuals with more CD39low/- Tregs and from individuals with genetic polymorphism associated with lower CD39 expression (rs10748643) had more cytotoxicity. Isolated CD39- CAR Tregs had elevated granzyme B expression and cytotoxicity compared to the CD39+ CAR Treg subset. Genetic overexpression of CD39 in CD39low CAR Tregs reduced their cytotoxicity. Importantly, ß cells upregulated protein surface expression of PD-L1 and PD-L2 in response to A2-CAR Tregs. Blockade of PD-L1/PD-L2 increased ß cell death in A2-CAR Treg co-cultures suggesting that the PD-1/PD-L1 pathway is important in protecting islet ß cells in the setting of CAR immunotherapy. In summary, introduction of CAR can enhance biological differences in subsets of Tregs. CD39+ Tregs represent a safer choice for CAR Treg therapies targeting tissues for tolerance induction.
Assuntos
Apirase , Receptores de Antígenos Quiméricos , Linfócitos T Reguladores , Humanos , Apirase/imunologia , Apirase/metabolismo , Linfócitos T Reguladores/imunologia , Receptores de Antígenos Quiméricos/imunologia , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismo , Citotoxicidade Imunológica , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/metabolismo , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/terapia , Antígeno HLA-A2/imunologia , Antígeno HLA-A2/genética , Antígeno HLA-A2/metabolismo , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Células Secretoras de Insulina/imunologia , Células Secretoras de Insulina/metabolismo , Antígenos CDRESUMO
INTRODUCTION: The Environmental Determinants of Islet Autoimmunity (ENDIA) Study is an ongoing Australian prospective cohort study investigating how modifiable prenatal and early-life exposures drive the development of islet autoimmunity and type 1 diabetes (T1D) in children. In this profile, we describe the cohort's parental demographics, maternal and neonatal outcomes and human leukocyte antigen (HLA) genotypes. RESEARCH DESIGN AND METHODS: Inclusion criteria were an unborn child, or infant aged less than 6 months, with a first-degree relative (FDR) with T1D. The primary outcome was persistent islet autoimmunity, with children followed until a T1D diagnosis or 10 years of age. Demographic data were collected at enrollment. Lifestyle, clinical and anthropometric data were collected at each visit during pregnancy and clinical pregnancy and birth data were verified against medical case notes. Data were compared between mothers with and without T1D. HLA genotyping was performed on the ENDIA child and all available FDRs. RESULTS: The final cohort comprised 1473 infants born to 1214 gestational mothers across 1453 pregnancies, with 80% enrolled during pregnancy. The distribution of familial T1D probands was 62% maternal, 28% paternal and 11% sibling. The frequency of high-risk HLA genotypes was highest in T1D probands, followed by ENDIA infants, and lowest among unaffected family members. Mothers with T1D had higher rates of pregnancy complications and perinatal intervention, and larger babies of shorter gestation. Parent demographics were comparable to the Australian population for age, parity and obesity. A greater percentage of ENDIA parents were Australian born, lived in a major city and had higher socioeconomic advantage and education. CONCLUSIONS: This comprehensive profile provides the context for understanding ENDIA's scope, methodology, unique strengths and limitations. Now fully recruited, ENDIA will provide unique insights into the roles of early-life factors in the development of islet autoimmunity and T1D in the Australian environment. TRIAL REGISTRATION NUMBER: ACTRN12613000794707.
Assuntos
Autoimunidade , Diabetes Mellitus Tipo 1 , Humanos , Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/etiologia , Feminino , Gravidez , Austrália/epidemiologia , Estudos Prospectivos , Masculino , Criança , Lactente , Recém-Nascido , Fatores de Risco , Adulto , Ilhotas Pancreáticas/imunologia , Estudos Longitudinais , Seguimentos , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Pré-Escolar , Pais , Genótipo , Antígenos HLA/genéticaRESUMO
The longevity of grafts remains a major challenge in allogeneic transplantation due to immune rejection. Systemic immunosuppression can impair graft function and can also cause severe adverse effects. Here, we report a local immuno-protective strategy to enhance post-transplant persistence of allografts using a mesenchymal stem cell membrane-derived vesicle (MMV)-crosslinked hydrogel (MMV-Gel). MMVs are engineered to upregulate expression of Fas ligand (FasL) and programmed death ligand 1 (PD-L1). The MMVs are retained within the hydrogel by crosslinking. The immuno-protective microenvironment of the hydrogel protects allografts by presenting FasL and PD-L1. The binding of these ligands to T effector cells, the dominant contributors to graft destruction and rejection, results in apoptosis of T effector cells and generation of regulatory T cells. We demonstrate that implantation with MMV-Gel prolongs the survival and function of grafts in mouse models of allogeneic pancreatic islet cells and skin transplantation.
Assuntos
Membrana Celular , Reagentes de Ligações Cruzadas , Hidrogéis , Transplante das Ilhotas Pancreáticas , Transplante de Pele , Reagentes de Ligações Cruzadas/química , Hidrogéis/química , Aloenxertos , Células-Tronco/imunologia , Membrana Celular/imunologia , Proteína Ligante Fas/imunologia , Antígeno B7-H1/imunologia , Proliferação de Células , Linfócitos T/imunologia , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/cirurgia , Pele/imunologia , Ativação Linfocitária , Feminino , Animais , Camundongos , Sobrevivência de Enxerto , Transplante HomólogoRESUMO
Type 1 diabetes (T1D) is a chronic disease characterized by self-destruction of insulin-producing pancreatic ß cells by cytotoxic T cell activity. However, the pathogenic mechanism of T cell infiltration remains obscure. Recently, tissue-resident memory T (TRM) cells have been shown to contribute to cytotoxic T cell recruitment. TRM cells are found present in human pancreas and are suggested to modulate immune homeostasis. Here, the role of TRM cells in the development of T1D is investigated. The presence of TRM cells in pancreatic islets is observed in non-obese diabetic (NOD) mice before T1D onset. Mechanistically, elevated fatty acid-binding protein 4 (FABP4) potentiates the survival and alarming function of TRM cells by promoting fatty acid utilization and C-X-C motif chemokine 10 (CXCL10) secretion, respectively. In NOD mice, genetic deletion of FABP4 or depletion of TRM cells using CD69 neutralizing antibodies resulted in a similar reduction of pancreatic cytotoxic T cell recruitment, a delay in diabetic incidence, and a suppression of CXCL10 production. Thus, targeting FABP4 may represent a promising therapeutic strategy for T1D.
Assuntos
Quimiocina CXCL10 , Diabetes Mellitus Tipo 1 , Proteínas de Ligação a Ácido Graxo , Ilhotas Pancreáticas , Camundongos Endogâmicos NOD , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/genética , Animais , Proteínas de Ligação a Ácido Graxo/genética , Proteínas de Ligação a Ácido Graxo/metabolismo , Proteínas de Ligação a Ácido Graxo/imunologia , Camundongos , Quimiocina CXCL10/genética , Quimiocina CXCL10/metabolismo , Quimiocina CXCL10/imunologia , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/metabolismo , Células T de Memória/imunologia , Células T de Memória/metabolismo , Modelos Animais de Doenças , HumanosRESUMO
AIM: This study aimed to evaluate characteristics of autoimmunity in individuals who have a type 2 diagnosis and are relatives of children with type 1 diabetes. METHODS: Pre-diagnosis samples (median 17 months before onset) from relatives who were later diagnosed with type 2 diabetes were measured for autoantibodies to glutamate decarboxylase 65 (GADA), islet antigen-2 (IA-2A), zinc transporter 8 (ZnT8A) and insulin (IAA) as well as the type 1 diabetes genetic risk score (GRS2). Associations between islet autoantibodies, insulin treatment and GRS2 were analysed using Fisher's exact and t-tests. RESULTS: Among 226 relatives (64% men; mean age at sampling 41 years; mean age 54 years at diagnosis), 32 (14%) were islet autoantibody-positive for at least one autoantibody more than a decade before diagnosis. Approximately half of these (n = 15) were treated with insulin. GADA-positivity was higher in insulin-treated relatives than in non-insulin-treated relatives (12/18 [67%] vs. 6/18 [33%], p < 0.001). IAA-positivity was observed in 13/32 (41%) of relatives with autoantibodies. GRS2 scores were increased in autoantibody-positive relatives (p = 0.032), but there was no clear evidence for a difference according to treatment (p = 0.072). CONCLUSION: This study highlights the importance of measuring islet autoantibodies, including IAA, in relatives of people with type 1 diabetes to avoid misdiagnosis.
Assuntos
Autoanticorpos , Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Ilhotas Pancreáticas , Humanos , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/epidemiologia , Autoanticorpos/sangue , Masculino , Feminino , Diabetes Mellitus Tipo 2/imunologia , Diabetes Mellitus Tipo 2/diagnóstico , Adulto , Pessoa de Meia-Idade , Criança , Ilhotas Pancreáticas/imunologia , Glutamato Descarboxilase/imunologia , Transportador 8 de Zinco/imunologia , Insulina/imunologia , Insulina/uso terapêutico , Adolescente , Família , Pré-Escolar , Predisposição Genética para DoençaRESUMO
OBJECTIVE: Type 1 diabetes (T1D) screening programmes testing islet autoantibodies (IAbs) in childhood can reduce life-threatening diabetic ketoacidosis. General population screening is required to detect the majority of children with T1D, since in >85% there is no family history. Age 3-5 years has been proposed as an optimal age for a single screen approach. DESIGN: Capillary samples were collected from children attending their preschool vaccination and analysed for IAbs to insulin, glutamic acid decarboxylase, islet antigen-2 and zinc transporter 8 using radiobinding/luciferase immunoprecipitation system assays. Acceptability was assessed using semistructured interviews and open-ended postcard questionnaires with parents. SETTING: Two primary care practices in Oxfordshire, UK. MAIN OUTCOME MEASURES: The ability to collect capillary blood to test IAbs in children at the routine preschool vaccination (3.5-4 years). RESULTS: Of 134 parents invited, 66 (49%) were recruited (median age 3.5 years (IQR 3.4-3.6), 26 (39.4%) male); 63 provided a sample (97% successfully), and one participant was identified with a single positive IAb. Parents (n=15 interviews, n=29 postcards) were uniformly positive about screening aligned to vaccination and stated they would have been less likely to take part had screening been a separate visit. Themes identified included preparedness for T1D and the long-term benefit outweighing short-term upset. The perceived volume of the capillary sample was a potential concern and needs optimising. CONCLUSIONS: Capillary IAb testing is a possible method to screen children for T1D. Aligning collection to the preschool vaccination visit can be convenient for families without the need for an additional visit.
Assuntos
Autoanticorpos , Diabetes Mellitus Tipo 1 , Programas de Rastreamento , Humanos , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/diagnóstico , Autoanticorpos/sangue , Masculino , Pré-Escolar , Feminino , Programas de Rastreamento/métodos , Vacinação , Proteínas Tirosina Fosfatases Classe 8 Semelhantes a Receptores/imunologia , Ilhotas Pancreáticas/imunologia , Pais , Estudo de Prova de Conceito , Transportador 8 de Zinco/imunologia , Glutamato Descarboxilase/imunologiaRESUMO
Given the proven benefits of screening to reduce diabetic ketoacidosis (DKA) likelihood at the time of stage 3 type 1 diabetes diagnosis, and emerging availability of therapy to delay disease progression, type 1 diabetes screening programmes are being increasingly emphasised. Once broadly implemented, screening initiatives will identify significant numbers of islet autoantibody-positive (IAb+) children and adults who are at risk of (confirmed single IAb+) or living with (multiple IAb+) early-stage (stage 1 and stage 2) type 1 diabetes. These individuals will need monitoring for disease progression; much of this care will happen in non-specialised settings. To inform this monitoring, JDRF in conjunction with international experts and societies developed consensus guidance. Broad advice from this guidance includes the following: (1) partnerships should be fostered between endocrinologists and primary-care providers to care for people who are IAb+; (2) when people who are IAb+ are initially identified there is a need for confirmation using a second sample; (3) single IAb+ individuals are at lower risk of progression than multiple IAb+ individuals; (4) individuals with early-stage type 1 diabetes should have periodic medical monitoring, including regular assessments of glucose levels, regular education about symptoms of diabetes and DKA, and psychosocial support; (5) interested people with stage 2 type 1 diabetes should be offered trial participation or approved therapies; and (6) all health professionals involved in monitoring and care of individuals with type 1 diabetes have a responsibility to provide education. The guidance also emphasises significant unmet needs for further research on early-stage type 1 diabetes to increase the rigour of future recommendations and inform clinical care.
Assuntos
Autoanticorpos , Diabetes Mellitus Tipo 1 , Humanos , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/diagnóstico , Autoanticorpos/imunologia , Autoanticorpos/sangue , Consenso , Ilhotas Pancreáticas/imunologia , Progressão da Doença , Cetoacidose Diabética/diagnóstico , Cetoacidose Diabética/imunologiaRESUMO
Background: Type 1 diabetes (T1D) is preceded by a heterogenous pre-clinical phase, islet autoimmunity (IA). We aimed to identify pre vs. post-IA seroconversion (SV) changes in DNAm that differed across three IA progression phenotypes, those who lose autoantibodies (reverters), progress to clinical T1D (progressors), or maintain autoantibody levels (maintainers). Methods: This epigenome-wide association study (EWAS) included longitudinal DNAm measurements in blood (Illumina 450K and EPIC) from participants in Diabetes Autoimmunity Study in the Young (DAISY) who developed IA, one or more islet autoantibodies on at least two consecutive visits. We compared reverters - individuals who sero-reverted, negative for all autoantibodies on at least two consecutive visits and did not develop T1D (n=41); maintainers - continued to test positive for autoantibodies but did not develop T1D (n=60); progressors - developed clinical T1D (n=42). DNAm data were measured before (pre-SV visit) and after IA (post-SV visit). Linear mixed models were used to test for differences in pre- vs post-SV changes in DNAm across the three groups. Linear mixed models were also used to test for group differences in average DNAm. Cell proportions, age, and sex were adjusted for in all models. Median follow-up across all participants was 15.5 yrs. (interquartile range (IQR): 10.8-18.7). Results: The median age at the pre-SV visit was 2.2 yrs. (IQR: 0.8-5.3) in progressors, compared to 6.0 yrs. (IQR: 1.3-8.4) in reverters, and 5.7 yrs. (IQR: 1.4-9.7) in maintainers. Median time between the visits was similar in reverters 1.4 yrs. (IQR: 1-1.9), maintainers 1.3 yrs. (IQR: 1.0-2.0), and progressors 1.8 yrs. (IQR: 1.0-2.0). Changes in DNAm, pre- vs post-SV, differed across the groups at one site (cg16066195) and 11 regions. Average DNAm (mean of pre- and post-SV) differed across 22 regions. Conclusion: Differentially changing DNAm regions were located in genomic areas related to beta cell function, immune cell differentiation, and immune cell function.
Assuntos
Autoanticorpos , Autoimunidade , Metilação de DNA , Diabetes Mellitus Tipo 1 , Progressão da Doença , Ilhotas Pancreáticas , Humanos , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/genética , Feminino , Masculino , Autoimunidade/genética , Ilhotas Pancreáticas/imunologia , Autoanticorpos/sangue , Autoanticorpos/imunologia , Criança , Adolescente , Estudos Longitudinais , Pré-Escolar , Estudo de Associação Genômica Ampla , Epigênese GenéticaRESUMO
Given the proven benefits of screening to reduce diabetic ketoacidosis (DKA) likelihood at the time of stage 3 type 1 diabetes diagnosis, and emerging availability of therapy to delay disease progression, type 1 diabetes screening programs are being increasingly emphasized. Once broadly implemented, screening initiatives will identify significant numbers of islet autoantibody-positive (IAb+) children and adults who are at risk for (confirmed single IAb+) or living with (multiple IAb+) early-stage (stage 1 and stage 2) type 1 diabetes. These individuals will need monitoring for disease progression; much of this care will happen in nonspecialized settings. To inform this monitoring, JDRF, in conjunction with international experts and societies, developed consensus guidance. Broad advice from this guidance includes the following: 1) partnerships should be fostered between endocrinologists and primary care providers to care for people who are IAb+; 2) when people who are IAb+ are initially identified, there is a need for confirmation using a second sample; 3) single IAb+ individuals are at lower risk of progression than multiple IAb+ individuals; 4) individuals with early-stage type 1 diabetes should have periodic medical monitoring, including regular assessments of glucose levels, regular education about symptoms of diabetes and DKA, and psychosocial support; 5) interested people with stage 2 type 1 diabetes should be offered trial participation or approved therapies; and 6) all health professionals involved in monitoring and care of individuals with type 1 diabetes have a responsibility to provide education. The guidance also emphasizes significant unmet needs for further research on early-stage type 1 diabetes to increase the rigor of future recommendations and inform clinical care.
Assuntos
Autoanticorpos , Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/diagnóstico , Humanos , Autoanticorpos/sangue , Autoanticorpos/imunologia , Consenso , Ilhotas Pancreáticas/imunologiaRESUMO
BACKGROUND & AIMS: Maternal gluten intake in relation to child's risk of type 1 diabetes has been studied in few prospective studies considering the diet during pregnancy but none during lactation. Our aim was to study whether gluten, cereals, or dietary fiber in maternal diet during pregnancy and lactation is associated with the risk of islet autoimmunity or type 1 diabetes in the offspring. METHODS: We included 4943 children with genetic susceptibility to type 1 diabetes from the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) Study, born between 1996 and 2004. Maternal intake of gluten, different types of cereals, and dietary fiber were derived from a semi-quantitative validated food frequency questionnaire covering the eighth month of pregnancy and the third month of lactation. Children were monitored for islet autoantibodies up to age of 15 years and type 1 diabetes until year 2017. Risk of islet autoimmunity and clinical type 1 diabetes were estimated using Cox regression model, adjusted for energy intake, child's sex, HLA genotype, and familial diabetes. RESULTS: Altogether 312 children (6.4%) developed islet autoimmunity at median age of 3.5 (IQR 1.7, 6.6) years and 178 children (3.6%) developed type 1 diabetes at median age of 7.1 (IQR 4.3, 10.6) years. Gluten intake during pregnancy was not associated with islet autoimmunity (HR 0.96; 95% CI 0.68, 1.35), per 1 g/MJ increase in intake nor type 1 diabetes (HR 0.96; 95% CI 0.62, 1.50) in the offspring. Higher barley consumption during lactation was associated with increased risk of type 1 diabetes (HR 3.25; 95% CI 1.21, 8.70) per 1 g/MJ increase in intake. Maternal intake of other cereals or dietary fiber was not associated with the offspring outcomes. CONCLUSIONS: We observed no association between maternal intake of gluten, most consumed cereals, or dietary fiber during pregnancy or lactation and the risk of islet autoimmunity or type 1 diabetes in children from a high-risk population.
Assuntos
Autoimunidade , Diabetes Mellitus Tipo 1 , Fibras na Dieta , Grão Comestível , Glutens , Lactação , Humanos , Diabetes Mellitus Tipo 1/imunologia , Feminino , Gravidez , Glutens/efeitos adversos , Criança , Pré-Escolar , Masculino , Finlândia , Lactente , Fatores de Risco , Dieta , Adolescente , Fenômenos Fisiológicos da Nutrição Materna , Estudos Prospectivos , Ilhotas Pancreáticas/imunologia , Efeitos Tardios da Exposição Pré-Natal , AdultoRESUMO
While inflammation is beneficial for insulin secretion during homeostasis, its transformation adversely affects ß cells and contributes to diabetes. However, the regulation of islet inflammation for maintaining glucose homeostasis remains largely unknown. Here, we identified pericytes as pivotal regulators of islet immune and ß cell function in health. Islets and pancreatic pericytes express various cytokines in healthy humans and mice. To interfere with the pericytic inflammatory response, we selectively inhibited the TLR/MyD88 pathway in these cells in transgenic mice. The loss of MyD88 impaired pericytic cytokine production. Furthermore, MyD88-deficient mice exhibited skewed islet inflammation with fewer cells, an impaired macrophage phenotype, and reduced IL-1ß production. This aberrant pericyte-orchestrated islet inflammation was associated with ß cell dedifferentiation and impaired glucose response. Additionally, we found that Cxcl1, a pericytic MyD88-dependent cytokine, promoted immune IL-1ß production. Treatment with either Cxcl1 or IL-1ß restored the mature ß cell phenotype and glucose response in transgenic mice, suggesting a potential mechanism through which pericytes and immune cells regulate glucose homeostasis. Our study revealed pericyte-orchestrated islet inflammation as a crucial element in glucose regulation, implicating this process as a potential therapeutic target for diabetes.
Assuntos
Inflamação , Interleucina-1beta , Fator 88 de Diferenciação Mieloide , Pericitos , Transdução de Sinais , Animais , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Camundongos , Pericitos/metabolismo , Pericitos/patologia , Pericitos/imunologia , Humanos , Inflamação/patologia , Inflamação/metabolismo , Inflamação/genética , Inflamação/imunologia , Interleucina-1beta/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Camundongos Transgênicos , Receptores Toll-Like/metabolismo , Receptores Toll-Like/genética , Quimiocina CXCL1/metabolismo , Quimiocina CXCL1/genética , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/patologia , Camundongos Knockout , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Células Secretoras de Insulina/imunologia , Masculino , Glucose/metabolismoRESUMO
BACKGROUND: The Trial to Reduce IDDM in the Genetically at Risk (TRIGR) (NCT00179777) found no difference type 1 diabetes risk between hydrolyzed and regular infant formula. However, cow milk consumption during childhood is consistently linked to type 1 diabetes risk in prospective cohort studies. OBJECTIVES: Our primary aim was to study whether humoral immune responses to cow milk and cow milk consumption are associated with type 1 diabetes in TRIGR children. METHODS: TRIGR comprised 2159 children with genetic susceptibility to type 1 diabetes born between 2002 and 2007 in 15 countries. Children were randomly assigned into groups receiving extensively hydrolyzed casein or a regular cow milk formula and followed up until age 10 y. Type 1 diabetes-related autoantibodies and antibodies to cow milk proteins were analyzed. Infant formula intake was measured by structured dietary interviews and milk consumption with a food frequency questionnaire. Associations of milk antibodies and milk consumption with risk to develop type 1 diabetes were analyzed using Cox survival model. RESULTS: Cow milk antibody concentrations both in cord blood [hazards ratio (HR) for islet autoimmunity: 1.30; 95% CI: 1.05, 1.61; HR for type 1 diabetes: 1.32; 95% CI: 1.02, 1.71] and longitudinally from birth to 3 years (HR for islet autoimmunity: 1.39; 95% CI: 1.07, 1.81; HR for type 1 diabetes: 1.43; 95% CI: 1.04, 1.96) were associated with increased risk of developing type 1 diabetes. The amount of regular infant formula was associated with reduced islet autoimmunity risk in the regular infant formula group (HR: 0.92; 95% CI: 0.85, 0.99). Furthermore, frequent liquid milk consumption after infancy was associated with increased risk of islet autoimmunity or type 1 diabetes. CONCLUSIONS: Elevated cow milk antibody concentrations and high consumption of liquid milk after infancy are related to type 1 diabetes development in children with an increased genetic susceptibility to type 1 diabetes. Enhanced antibody concentrations to cow milk may provide a biomarker of immune system prone to develop islet autoimmunity. This trial was registered at clinicaltrials.gov as NCT00179777.