To Type 1 Diabetes Research Articles

Differential lipid signaling from CD4+ and CD8+ T cells contributes to type 1 diabetes development.

We reported that Ca2+-independent phospholipase A2β (iPLA2β)-derived lipids (iDLs) contribute to type 1 diabetes (T1D) onset. As CD4+ and CD8+ T cells are critical in promoting β-cell death, we tested the hypothesis that iDL signaling from these cells participates in T1D development. CD4+ and CD8+ T cells from wild-type non-obese diabetic (NOD) and NOD.iPLA2β+/- (NOD.HET) mice were administered in different combinations to immunodeficient NOD.scid. In mice receiving only NOD T cells, T1D onset was rapid (5 weeks), incidence 100% by 20 weeks, and islets absent. In contrast, onset was delayed 1 week and incidence reduced 40%-50% in mice receiving combinations that included NOD.HET T cells. Consistently, islets from these non-diabetic mice were devoid of infiltrate and contained insulin-positive β-cells. Reduced iPLA2β led to decreased production of proinflammatory lipids from CD4+ T cells including prostaglandins and dihydroxyeicosatrienoic acids (DHETs), products of soluble epoxide hydrolase (sEH), and inhibition of their signaling decreased (by 82%) IFNγ+CD4+ cells abundance. However, only DHETs production was reduced from CD8+ T cells and was accompanied by decreases in sEH and granzyme B. These findings suggest that differential select iDL signaling in CD4+ and CD8+ T cells contributes to T1D development, and that therapeutics targeting such signaling might be considered to counter T1D.

The Impact of Thyroiditis on the Immune Profile in Young Patients with Uncomplicated Type 1 Diabetes.

Autoimmune thyroid disease (AIT) is the most frequently linked autoimmune condition to type 1 diabetes (T1D). The analysis of immune profiles could provide valuable insights into the study of these diseases. This knowledge could play a crucial role in understanding the relationship between immune profiles and microcirculation structures and functions. The present study aimed to test the hypothesis that cytokine levels in T1D patients without and those with comorbid Hashimoto's disease differ significantly. The total study group (total T1D) consisted of 62 diabetic young patients: 43 T1D and 19 T1D + AIT matched for age, age at onset, and duration of diabetes. The control group consisted of 32 healthy young subjects. The levels of cytokines (including TNF-α, IL-35, IL-4, IL-10, IL-18, IL-12, VEGF, and angiogenin) were quantified throughout this investigation. A comparative assessment of the cytokines profiles between the control group and total T1D revealed a statistically significant elevation in the levels of IL-4, TNF-α, IL-18, VEGF, and angiogenin, accompanied by a notable decline in IL-10. However, IL-35 and IL-12 exhibited comparable levels between the two groups. A comparison of cytokine levels between T1D + AIT and T1D groups revealed that only angiogenin levels were statistically significantly higher in T1D + AIT. The results of our study indicated that the alterations in cytokine levels associated with AIT did not correspond to the observed changes in T1D-related outcomes. The sole notable observation was the elevation of angiogenin expression, an angiogenic factor.

330-OR: Narrow Variation of Glucose Inflection Points (IPs) during Progression to Type 1 Diabetes (T1D) Stratified by Demographic and Genetic Differences in Autoantibody-Positive (Ab+) Individuals

330-OR: Narrow Variation of Glucose Inflection Points (IPs) during Progression to Type 1 Diabetes (T1D) Stratified by Demographic and Genetic Differences in Autoantibody-Positive (Ab+) Individuals

A strategy based on integer programming for optimal dosing and timing of preventive hypoglycemic treatments in type 1 diabetes management

Background and objectivesOne of the major problems related to type 1 diabetes (T1D) management is hypoglycemia, a condition characterized by low blood glucose levels and responsible for reduced quality of life and increased mortality. Fast-acting carbohydrates, also known as hypoglycemic treatments (HT), can counteract this event. In the literature, dosage and timing of HT are usually based on heuristic rules. In the present work, we propose an algorithm for mitigating hypoglycemia by suggesting preventive HT consumption, with dosages and timing determined by solving an optimization problem. MethodsBy leveraging integer programming and linear inequality constraints, the algorithm can bind the amount of suggested carbohydrates to standardized quantities (i.e., those available in “off-the-shelf” HT) and the minimal distance between consecutive suggestions (to reduce the nuisance for patients). ResultsThe proposed method was tested in silico and compared with competitor algorithms using the UVa/Padova T1D simulator. At the cost of a slight increase of HT consumed per day, the proposed algorithm produces the lowest median and interquartile range of the time spent in hypoglycemia, with a statistically significant improvement over most competitor algorithms. Also, the average number of hypoglycemic events per day is reduced to 0 in median. ConclusionsThanks to its positive performances and reduced computational burden, the proposed algorithm could be a candidate tool for integration in a DSS aimed at improving T1D management.

GPR41 deficiency aggravates type 1 diabetes in streptozotocin-treated mice by promoting dendritic cell maturation.

Disturbances in intestinal immune homeostasis predispose susceptible individuals to type 1 diabetes (T1D). G-protein-coupled receptor 41 (GPR41) is a receptor for short-chain fatty acids (SCFAs) mainly produced by gut microbiota, which plays key roles in maintaining intestinal homeostasis. In this study, we investigated the role of GPR41 in the progression of T1D. In non-obese diabetic (NOD) mice, we found that aberrant reduction of GPR41 expression in the pancreas and colons was associated with the development of T1D. GPR41-deficient (Gpr41-/-) mice displayed significantly exacerbated streptozotocin (STZ)-induced T1D compared to wild-type mice. Furthermore, Gpr41-/- mice showed enhanced gut immune dysregulation and increased migration of gut-primed IFN-γ+ T cells to the pancreas. In bone marrow-derived dendritic cells from Gpr41-/- mice, the expression of suppressor of cytokine signaling 3 (SOCS) was significantly inhibited, while the phosphorylation of STAT3 was significantly increased, thus promoting dendritic cell (DC) maturation. Furthermore, adoptive transfer of bone marrow-derived dendritic cells (BMDC) from Gpr41-/- mice accelerated T1D in irradiated NOD mice. We conclude that GPR41 is essential for maintaining intestinal and pancreatic immune homeostasis and acts as a negative regulator of DC maturation in T1D. GPR41 may be a potential therapeutic target for T1D.

Fatty liver index is an independent risk factor for all-cause mortality and major cardiovascular events in type 1 diabetes: an 11-year observational study

BackgroundNon-alcoholic fatty liver disease (NAFLD), identified by the Fatty Liver Index (FLI), is associated with increased mortality and cardiovascular (CV) outcomes. Whether this also applies to type 1 diabetes (T1D) has not been yet reported.MethodsWe prospectively observed 774 subjects with type 1 diabetes (males 52%, 30.3 ± 11.1 years old, diabetes duration (DD) 18.5 ± 11.6 years, HbA1c 7.8 ± 1.2%) to assess the associations between FLI (based on BMI, waist circumference, gamma-glutamyl transferase and triglycerides) and all-cause death and first CV events.ResultsOver a median 11-year follow-up, 57 subjects died (7.4%) and 49 CV events (6.7%) occurred among 736 individuals with retrievable incidence data. At baseline, FLI was < 30 in 515 subjects (66.5%), 30–59 in 169 (21.8%), and ≥ 60 in 90 (11.6%). Mortality increased steeply with FLI: 3.9, 10.1, 22.2% (p < 0.0001). In unadjusted Cox analysis, compared to FLI < 30, risk of death increased in FLI 30–59 (HR 2.85, 95% CI 1.49–5.45, p = 0.002) and FLI ≥ 60 (6.07, 3.27–11.29, p < 0.0001). Adjusting for Steno Type 1 Risk Engine (ST1-RE; based on age, sex, DD, systolic BP, LDL cholesterol, HbA1c, albuminuria, eGFR, smoking and exercise), HR was 1.52 (0.78–2.97) for FLI 30–59 and 3.04 (1.59–5.82, p = 0.001) for FLI ≥ 60. Inclusion of prior CV events slightly modified HRs. FLI impact was confirmed upon adjustment for EURODIAB Risk Engine (EURO-RE; based on age, HbA1c, waist-to-hip ratio, albuminuria and HDL cholesterol): FLI 30–59: HR 1.24, 0.62–2.48; FLI ≥ 60: 2.54, 1.30–4.95, p = 0.007), even after inclusion of prior CVD. CV events incidence increased with FLI: 3.5, 10.5, 17.2% (p < 0.0001). In unadjusted Cox, HR was 3.24 (1.65–6.34, p = 0.001) for FLI 30–59 and 5.41 (2.70–10.83, p < 0.0001) for FLI ≥ 60. After adjustment for ST1-RE or EURO-RE, FLI ≥ 60 remained statistically associated with risk of incident CV events, with trivial modification with prior CVD inclusion.ConclusionsThis observational prospective study shows that FLI is associated with higher all-cause mortality and increased risk of incident CV events in type 1 diabetes.

Intake of B vitamins and the risk of developing islet autoimmunity and type 1 diabetes in the TEDDY study

Purpose The aim was to study the association between dietary intake of B vitamins in childhood and the risk of islet autoimmunity (IA) and progression to type 1 diabetes (T1D) by the age of 10 years. MethodsWe followed 8500 T1D-susceptible children born in the U.S., Finland, Sweden, and Germany in 2004 -2010 from the Environmental Determinants of Diabetes in the Young (TEDDY) study, which is a prospective observational birth cohort. Dietary intake of seven B vitamins was calculated from foods and dietary supplements based on 24-h recall at 3 months and 3-day food records collected regularly from 6 months to 10 years of age. Cox proportional hazard models were adjusted for energy, HLA-genotype, first-degree relative with T1D, sex, and country. ResultsA total of 778 (9.2) children developed at least one autoantibody (any IA), and 335 (3.9%) developed multiple autoantibodies. 280 (3.3%) children had IAA and 319 (3.8%) GADA as the first autoantibody. 344 (44%) children with IA progressed to T1D. We observed that higher intake of niacin was associated with a decreased risk of developing multiple autoantibodies (HR 0.95; 95% CI 0.92, 0.98) per 1 mg/1000 kcal in niacin intake. Higher intake of pyridoxine (HR 0.66; 95% CI 0.46, 0.96) and vitamin B12 (HR 0.87; 95% CI 0.77, 0.97) was associated with a decreased risk of IAA-first autoimmunity. Higher intake of riboflavin (HR 1.38; 95% CI 1.05, 1.80) was associated with an increased risk of GADA-first autoimmunity. There were no associations between any of the B vitamins and the outcomes “any IA” and progression from IA to T1D. ConclusionIn this multinational, prospective birth cohort of children with genetic susceptibility to T1D, we observed some direct and inverse associations between different B vitamins and risk of IA.

Glycemic Response in Nonhuman Primates Fed Gluten-Free Rice Cakes Enriched with Soy, Pea, or Rice Protein and Its Correlation with Nutrient Composition.

Celiac disease (CD) is a chronic disease caused by the consumption of gluten foods and is closely related to type 1 diabetes (T1D). Adherence to a gluten-free (GF) diet is the cornerstone of treating CD, and certain plant proteins added to GF foods affect blood glucose to varying degrees. The aim of this study was to analyze and compare the changes in glycemic index (GI) and incremental area under the postprandial glucose tolerance curve (IAUC) of various foods through consumption of GF foods supplemented with certain plant proteins in non-human primates. The test foods were GF rice cakes with 5%, 10%, and 15% added single plant proteins (rice protein, soy protein, and pea protein) mixed with rice flour, as well as 5%, 10%, and 15% gluten rice cakes, and rice flour alone, for a total of 13 food items, and 12 healthy cynomolgus monkeys were examined for their glucose levels in the blood after fasting and after eating each test food (50 g) for 15, 30, 45, 60, 90, and 120 min after fasting and eating each test food. Fingertip blood glucose levels were measured, and the nutrient content of each food, including protein, fat, starch, ash, and amino acids, was examined. All foods tested had a low GI (<50) when analyzed using one-way ANOVA and nonparametric tests. Postprandial IAUC was significantly lower (p < 0.05) for GF rice cakes with 15% pea protein (499.81 ± 34.46) compared to GF rice cakes with 5% pea protein (542.19 ± 38.78), 15% soy protein (572.94 ± 72.74), and 15% rice protein (530.50 ± 14.65), and GF rice cakes with 15% wheat bran protein (533.19 ± 34.89). A multiple regression analysis showed that glycine was negatively associated with IAUC in GF rice cakes with 5%, 10%, and 15% pea protein added (p = 0.0031 < 0.01). Fat was negatively correlated with IAUC in GF rice cakes supplemented with 5%, 10%, and 15% soy protein (p = 0.0024 < 0.01). In this study, GF rice cakes made with added pea protein were superior to other gluten and GF rice cakes and had a small effect on postprandial glucose.

A novel, high-performance, low-volume, rapid luciferase immunoprecipitation system (LIPS) assay to detect autoantibodies to zinc transporter 8.

Zinc transporter 8 autoantibodies (ZnT8A) are thought to appear close to type 1 diabetes (T1D) onset and can identify high-risk multiple (≥2) autoantibody positive individuals. Radiobinding assays (RBA) are widely used for ZnT8A measurement but have limited sustainability. We sought to develop a novel, high-performance, non-radioactive luciferase immunoprecipitation system (LIPS) assay to replace RBA. A custom dual C-terminal ZnT8 (aa268-369; R325/W325) heterodimeric antigen, tagged with a NanoluciferaseTM (Nluc-ZnT8) reporter, and LIPS assay was developed. Assay performance was evaluated by testing sera from new onset T1D (n = 573), healthy schoolchildren (n = 521), and selected first-degree relatives (FDRs) from the Bart's Oxford family study (n = 617; 164 progressed to diabetes). In new-onset T1D, ZnT8A levels by LIPS strongly correlated with RBA (Spearman's r = 0.89; P < 0.0001), and positivity was highly concordant (94.3%). At a high specificity (95%), LIPS and RBA had comparable assay performance [LIPS pROC-AUC(95) 0.032 (95% CI: 0.029-0.036); RBA pROC-AUC(95) 0.031 (95% CI: 0.028-0.034); P = 0.376]. Overall, FDRs found positive by LIPS or RBA had a comparable 20-year diabetes risk (52.6% and 59.7%, respectively), but LIPS positivity further stratified T1D risk in FDRs positive for at least one other islet autoantibody detected by RBA (P = 0.0346). This novel, high-performance, cheaper, quicker, higher throughput, low blood volume Nluc-ZnT8 LIPS assay is a safe, non-radioactive alternative to RBA with enhanced sensitivity and ability to discriminate T1D progressors. This method offers an advanced approach to current strategies to screen the general population for T1D risk for immunotherapy trials and to reduce rates of diabetic ketoacidosis at diagnosis.

Relative Frequency of Islet Autoimmunity in Children and Adolescents with Autoimmune Thyroid Disease

The aim of the present study was to investigate islet autoimmunity and susceptibility to type 1 diabetes (T1D) in children/adolescents with autoimmune thyroid disease (AITD, and in family members of AITD patients with islet autoimmunity. Islet-cell cytoplasmic, glutamic-acid decarboxylase, and tyrosine-phosphatase autoantibodies (AAbs) were measured in 161 AITD patients [127 with autoimmune thyroiditis (AT); 34 with Graves’ disease (GD)], 20 family members of AITD patients with islet autoimmunity, and 155 age-matched controls. Islet autoimmunity was found in 10.6% of AITD patients, significantly more frequent than in controls (1.9%; p=0.002). A higher prevalence of islet AAbs was found in females with AITD (p=0.011) but not in males (p=0.16) and in AT (p=0.013) but not in GD patients (p=0.19), compared to corresponding controls. Two or three islet AAbs were found concurrently in six AITD patients with islet autoimmunity. They all developed T1D and had significantly higher islet AAbs titers (p=0.01) than AITD patients with single islet AAbs but normal glucose metabolism. T1D was found in 3.7% of AITD patients compared to 0.2% of the age-matched, general Croatian population. Islet AAbs were found in 5/20 family members of AITD patients with islet autoimmunity, among whom two developed T1D. None of the controls was positive for more than one islet AAb or developed T1D. Children/adolescents with AITD, particularly females and patients with AT, appear to represent a risk group for islet autoimmunity and T1D, as do family members of AITD patients with positive islet AAbs. However, these findings should be validated in larger studies.

Increased Frequency of the HLA-DRB1*04:04-DQA1*03-DQB1*03:02 Haplotype Among HLA-DQB1*06:02-Positive Children With Type 1 Diabetes.

HLA DR-DQ haplotypes largely define genetic susceptibility to type 1 diabetes (T1D). The DQB1*06:02 positive haplotype (DR15-DQ602) common in subjects of European ancestry is very rare among children with T1D. Among 4490 children with T1D in the Finnish Pediatric Diabetes Register 57 (1.3%) cases with DQB1*06:02 were identified in comparison to 26.1% of affected family-based association controls. There was no difference between DQB1*06:02 positive and negative children with T1D regarding sex, age, islet autoantibody distribution or autoantibody levels, but significant differences were seen in the frequency of the second class II HLA haplotypes. The most prevalent haplotype present with DQB1*06:02 was DRB1*04:04-DQA1*03-DQB1*03:02 which was found in 27 of 57 (47.4%) children compared to only 797/4433 (18.0%) among DQB1*06:02 negative cases (P<0.001, Chi-square test). The other common risk associated haplotypes, the DRB1*04:01-DQA1*03-DQB1*03:02 and (DR3)-DQA1*05-DQB1*02 were less prevalent in DQB1*06:02 positive than DQB1*06:02 negative children (P<0.001). HLA-B allele frequencies did not differ between DQB1*06:02 haplotypes in children with T1D and controls and neither in DRB1*04:04-DQA1*03-DQB1*03:02 haplotypes of DQB1*06:02 positive and negative T1D children. The increased frequency of DRB1*04:04 allele among DQB1*06:02 positive cases may indicate preferential ability of the DR404 molecule to present islet antigen epitopes despite of the competition by DQ602.

Shifts in isoform usage underlie transcriptional differences in regulatory T cells in type 1 diabetes

Genome-wide association studies have identified numerous loci with allelic associations to Type 1 Diabetes (T1D) risk. Most disease-associated variants are enriched in regulatory sequences active in lymphoid cell types, suggesting that lymphocyte gene expression is altered in T1D. Here we assay gene expression between T1D cases and healthy controls in two autoimmunity-relevant lymphocyte cell types, memory CD4+/CD25+ regulatory T cells (Treg) and memory CD4+/CD25- T cells, using a splicing event-based approach to characterize tissue-specific transcriptomes. Limited differences in isoform usage between T1D cases and controls are observed in memory CD4+/CD25- T-cells. In Tregs, 402 genes demonstrate differences in isoform usage between cases and controls, particularly RNA recognition and splicing factor genes. Many of these genes are regulated by the variable inclusion of exons that can trigger nonsense mediated decay. Our results suggest that dysregulation of gene expression, through shifts in alternative splicing in Tregs, contributes to T1D pathophysiology.

Measuring anti-islet autoimmunity in mouse and human by profiling peripheral blood antigen-specific CD4 T cells.

The endocrine pancreas is one of the most inaccessible organs of the human body. Its autoimmune attack leads to type 1 diabetes (T1D) in a genetically susceptible population and a lifelong need for exogenous insulin replacement. Monitoring disease progression by sampling peripheral blood would provide key insights into T1D immune-mediated mechanisms and potentially change preclinical diagnosis and the evaluation of therapeutic interventions. This effort has been limited to the measurement of circulating anti-islet antibodies, which despite a recognized diagnostic value, remain poorly predictive at the individual level for a fundamentally CD4 T cell-dependent disease. Here, peptide-major histocompatibility complex tetramers were used to profile blood anti-insulin CD4 T cells in mice and humans. While percentages of these were not directly informative, the state of activation of anti-insulin T cells measured by RNA and protein profiling was able to distinguish the absence of autoimmunity versus disease progression. Activated anti-insulin CD4 T cell were detected not only at time of diagnosis but also in patients with established disease and in some at-risk individuals. These results support the concept that antigen-specific CD4 T cells might be used to monitor autoimmunity in real time. This advance can inform our approach to T1D diagnosis and therapeutic interventions in the preclinical phase of anti-islet autoimmunity.

1451-P: Risk of Progression to Clinical Type 1 Diabetes in Older Adolescents Positive for Islet Autoantibodies

Objective: Evaluate progression to type 1 diabetes (T1D) among adolescents with persistent islet autoimmunity. Background: Few studies have continued to follow adolescents with islet autoimmunity through to young adulthood. With the emergence of treatments to delay clinical diabetes and general population screening, there is need to accurately predict and communicate risk for progression to T1D in autoantibody positive persons. Methods: Included in this analysis were 203 participants of prospective studies (DAISY, TEDDY Graduates, ASK) who were persistently positive for islet autoantibodies and free of diabetes between 13-15 y of age. Of those, 51% were female, 52% non-Hispanic white, and 32% had a first-degree T1D relative. Autoantibodies to insulin, GAD, IA-2, and ZnT8 were measured using standard radio-binding assays. Results: During the median 3.0 y (IQR 1.2-5.2) follow-up, 14.8% (n=30) of the participants progressed to T1D. The 5-year risk of progression to clinical diabetes was 33.1% (95%CI 20.0-51.7%) among adolescents with multiple autoantibodies vs 7.8% (95%CI 3.9-15.2%) in those with a single persistent autoantibody. Independent predictors of progression to diabetes included: multiple autoantibodies (HR=3.2, 95%CI 1.4-7.5, p=0.008) and higher baseline HbA1c (HR=1.7 per 0.5%, 95%CI 1.2-2.2. p=001). A receiver operating characteristic based on autoantibody status and HbA1c (AUC 0.78) did not improve significantly with addition of sex, ethnicity, and family history of T1D (AUC 0.81). Conclusion: One third of adolescents with multiple islet autoantibodies progress to clinical diabetes within 5 years, with baseline HbA1c being highly predictive of progression. Disclosure K.Waugh: None. C.Geno rasmussen: None. F.Dong: None. P.D.Gesualdo: None. B.I.Frohnert: Advisory Panel; Provention Bio, Inc. M.Rewers: Research Support; Provention Bio, Juvenile Diabetes Research Foundation (JDRF), Hemsley Charitable Trust, Dexcom, Inc., Janssen Research &amp; Development, LLC. Funding National Institutes of Health (5R01DK032493-36); JDRF (2-SRA-2022-1270-S-B)

190-LB: Differences in Postprandial and Counterregulatory Glucagon Excursions in Healthy Relatives to Type 1 Diabetes with Different Number of Islet Autoantibodies

Background and aims: Early changes in glucagon during the progression to type 1 diabetes (T1D) are not well understood. We investigate whether the glucagon responses to a mixed meal and hypoglycemia depend on the number of islet autoantibodies (Ab) in individuals at risk for T1D. Methods: Sixty healthy relatives of T1D with mean±SD age of 23.7±10.7 years, HbA1c of 5.3±0.3%, and BMI of 23.8±5.6 kg/m2 and zero (N=21), one (N=18), and ≥2 (N=21) Ab, were enrolled in an ancillary study from the NIH-funded TrialNet Pathway to Prevention study. Participants underwent a clinical test consisting of a mixed meal tolerance test (MMTT) followed by insulin-induced hypoglycemia. Glucagon was measured from -30 to 120 min around the MMTT and 0 to 40 min during hypoglycemia to estimate the Ab group differences in the meal and counter-regulatory glucagon responses assessed via the glucagon incremental area under the curve (iAUC). Results: There were significant differences in the net iAUC of the glucagon responses to the MMTT (p=0.024), while the group difference in the glucagon counter-regulation estimated via the total AUC approached significance (p=0.08). Conclusion: The study suggests that the glucagon responses to a meal and possibly, hypoglycemia, may be altered during the very early stages of the progression to T1D. Disclosure T. Igbe: None. E. Montaser: None. M. D. Breton: Consultant; Dexcom, Inc. Research Support; Dexcom, Inc. Consultant; Tandem Diabetes Care, Inc. Research Support; Tandem Diabetes Care, Inc., Novo Nordisk. Consultant; Roche Diabetes Care, Sanofi, Arecor. S. A. Brown: Research Support; Dexcom, Inc., Insulet Corporation, Tandem Diabetes Care, Inc. M. D. DeBoer: Research Support; Dexcom, Inc., Tandem Diabetes Care, Inc. A. L. McCall: None. B. Kovatchev: Speaker's Bureau; Tandem Diabetes Care, Inc. Research Support; Dexcom, Inc., Novo Nordisk, Tandem Diabetes Care, Inc. Other Relationship; Dexcom, Inc., Johnson &amp; Johnson Medical Devices Companies, Novo Nordisk, Sanofi. L. Farhy: Research Support; Dexcom, Inc., Novo Nordisk. Funding National Institute of Diabetes and Digestive and Kidney Diseases (DP3DK106907); Commonwealth Research Commercialization Fund (MF20-007-LS); The Leona M. and Harry B. Helmsley Charitable Trust (2204-05134); JDRF (2-SRA-2022-1260-S-B)

20-OR: Loss of Characteristic ß-Cell Function in Autoantibody-Positive (Ab+) Individuals during the Progression to Type 1 Diabetes (T1D)

We used correlations of C-peptide secretion between follow-up time points (autocorrelation) of Ab+ relatives in the TrialNet Pathway to Prevention study to assess the loss of characteristic β-cell function during progression to T1D. Measures of β-cell function: AUC C-peptide; C-peptide Index (30-0 min C-peptide)/(30-0 min glucose); and Index60 (composite of glucose and C-peptide during first 60 minutes of OGTT)] were assessed (table 1). Spearman correlations of AUC C-peptide from baseline to pre-diagnosis (6 months before) OGTTs of progressors (Pro; Age=8.7±3.6 yrs; n=182) were lower than correlations of AUC C-peptide from baseline to last OGTTs of non-progressors (NPro; Age=9.6±3.8 yrs; n=3,137; p&amp;lt;0.001 for all). Among Pro, correlations of AUC C-peptide from baseline to diagnosis OGTTs were considerably lower than correlations of AUC C-peptide from baseline to pre-diagnosis OGTTs (p=&amp;lt;0.001 for all). In conclusion, the lower C-peptide autocorrelation from baseline to last OGTTs of Pro compared to NPro indicates that β-cell function is already appreciably altered 6 months before diagnosis. Among Pro, the substantial decline of C-peptide autocorrelation from 6 months before diagnosis to diagnosis suggests a marked loss of β-cell function in that interval. Autocorrelation offers another approach for providing insight into β-cell compromise. Disclosure H.M.Ismail: Consultant; Rise Therapeutics. D.D.Cuthbertson: None. J.S.Skyler: Advisory Panel; Adocia, Altheia Sciences, Arecor, Avotres Inc., Bayer Inc., COUR Pharmaceuticals, Dance Biopharm/Aerami, Diasome, Enthera, Immnomolecular Therapeutics, Kriya Therapeutics, Oramed Pharmaceuticals, Orgenesis Inc., Precigen, Inc., ViaCyte, Inc., Board Member; Applied Therapeutics Inc., Dexcom, Inc., Consultant; Novo Nordisk, Sanofi, Signos, 4Immune, Other Relationship; Imcyse, Provention Bio, Inc. C.Evans-molina: Advisory Panel; Provention Bio, Inc., DiogenX, Avotres Inc., Neurodon, MaiCell Therapeutics, Other Relationship; Isla Technology, Bristol-Myers Squibb Company, Nimbus Therapeutics, Research Support; Lilly, Astellas Pharma Inc. J.Sosenko: None. Funding National Institute of Diabetes and Digestive and Kidney Diseases (1K23DK129799-01A1)

1290-P: Diabetes Provider Perceptions of Barriers and Benefits to Type 1 Diabetes Autoantibody Screening among Patients and Relatives

Background: This study highlights perceived benefits and barriers to type 1 diabetes (T1D) autoantibody screening rates in U.S. endocrinology practices. Methods: Fifty eligible endocrinology providers participated in a 15-question survey distributed via Qualtrics. Participants were recruited from the T1D Exchange Quality Improvement Collaborative. Data was cleaned, sorted, and analyzed. Summary statistics, including frequencies and proportions for categorical variables were evaluated and plotted using bar charts. z Results: Overall, 82% of providers stated interest towards autoantibody screening in their clinics. The following were ranked as benefits of autoantibody screening: opportunity for early diabetes management (90%), enrollment in research projects (84%), clinical guidance and diagnosing abilities (80%), and DKA prevention at diagnosis (76%). Providers identified multiple barriers to autoantibody screening in clinical practice including the associated cost and anxiety for patients, as well as limited staff time and resources (Figures 1, 2). Conclusion: The majority of surveyed providers feel confident recommending autoantibody screening for patients and those at risk for diabetes. However, clinic limitations exist that may affect the feasibility of this in practice. These barriers should be targeted with specific interventions moving forward. Disclosure E.L.Ospelt: None. C.Sullivan: None. S.Majidi: None. I.Lorincz: None. O.Ebekozien: Advisory Panel; Medtronic, Research Support; Eli Lilly and Company, Dexcom, Inc. H.Hardison: None. N.Rioles: None. N.Noor: None. S.Crossen: None. A.Smego: None. G.Aleppo: Advisory Panel; Medscape, Consultant; Bayer Inc., Insulet Corporation, Research Support; Dexcom, Inc., Eli Lilly and Company, Emmes, Insulet Corporation, Fractyl Health, Inc., WellDoc, Speaker's Bureau; Dexcom, Inc. J.Friedman: None. D.Eng: None.

Bruton’s tyrosine kinase impacts IgA repertoire and microbiome composition in non-obese diabetic mice

Abstract The microbiome has emerged as a contributor to type 1 diabetes (T1D), but how interactions between the microbiome and the mucosal immune system lead to or prevent T1D is not clear. Previously, we found that deletion of the B cell signaling protein Bruton’s Tyrosine Kinase (BTK) selectively eliminates autoreactive B cells and autoantibodies, preventing T1D development. However, we discovered that this disease protection is microbiome-dependent, as it disappears in cleaner facilities. We hypothesize that disruption of BTK-mediated B cell receptor (BCR) signaling promotes the growth of particular microbes that are protective against T1D by altering IgA production. Thus, the objective of this study is to determine how BTK-deficiency affects the IgA repertoire, shapes the gut microbiome, and synergistically prevents T1D. First, we performed IgA-seq to assess how BTK-deficiency alters IgA-coating of the microbiota. Then, we characterized the microbiomes of non-obese diabetic (NOD) mouse colonies living in distinct environments using 16S sequencing and conducted disease studies to track T1D development. We found that BTK-deficiency altered the ability of IgA to coat microbiota in the small intestine and colon. We also found that BTK-deficiency significantly impacts the composition of the microbiome in NOD mice living in distinct facilities. BTK-deficient mice have increased commensal diversity and enrichment of specific microbes. Based on these findings, we conclude that disruption of BTK-mediated BCR signaling alters IgA production and microbiome composition, with downstream effects on T1D pathogenesis. Supported by grants from NIH (R01-DK-084246I) and Veteran's Affairs (101-BX-002882)

Glia maturation factor beta deficiency protects against diabetic osteoporosis by suppressing osteoclast hyperactivity

Excessive osteoclast activation, which depends on dramatic changes in actin dynamics, causes osteoporosis (OP). The molecular mechanism of osteoclast activation in OP related to type 1 diabetes (T1D) remains unclear. Glia maturation factor beta (GMFB) is considered a growth and differentiation factor for both glia and neurons. Here, we demonstrated that Gmfb deficiency effectively ameliorated the phenotype of T1D-OP in rats by inhibiting osteoclast hyperactivity. In vitro assays showed that GMFB participated in osteoclast activation rather than proliferation. Gmfb deficiency did not affect osteoclast sealing zone (SZ) formation but effectively decreased the SZ area by decreasing actin depolymerization. When GMFB was overexpressed in Gmfb-deficient osteoclasts, the size of the SZ area was enlarged in a dose-dependent manner. Moreover, decreased actin depolymerization led to a decrease in nuclear G-actin, which activated MKL1/SRF-dependent gene transcription. We found that pro-osteoclastogenic factors (Mmp9 and Mmp14) were downregulated, while anti-osteoclastogenic factors (Cftr and Fhl2) were upregulated in Gmfb KO osteoclasts. A GMFB inhibitor, DS-30, targeting the binding site of GMFB and Arp2/3, was obtained. Biocore analysis revealed a high affinity between DS-30 and GMFB in a dose-dependent manner. As expected, DS-30 strongly suppressed osteoclast hyperactivity in vivo and in vitro. In conclusion, our work identified a new therapeutic strategy for T1D-OP treatment. The discovery of GMFB inhibitors will contribute to translational research on T1D-OP.

Association analysis between the TLR9 gene polymorphism rs352140 and type 1 diabetes.

To a great extent, genetic factors contribute to the susceptibility to type 1 diabetes (T1D) development, and by triggering immune imbalance, Toll-like receptor (TLR) 9 is involved in the development of T1D. However, there is a lack of evidence supporting a genetic association between polymorphisms in the TLR9 gene and T1D. In total, 1513 individuals, including T1D patients (n=738) and healthy control individuals (n=775), from the Han Chinese population were recruited for an association analysis of the rs352140 polymorphism of the TLR9 gene and T1D. rs352140 was genotyped by MassARRAY. The allele and genotype distributions of rs352140 in the T1D and healthy groups and those in different T1D subgroups were analyzed by the chi-squared test and binary logistic regression model. The chi-square test and Kruskal-Wallis H test were performed to explore the association between genotype and phenotype in T1D patients. The allele and genotype distributions of rs352140 were significantly different in T1D patients and healthy control individuals (p=0.019, p=0.035). Specifically, the T allele and TT genotype of rs352140 conferred a higher risk of T1D (OR=1.194, 95% CI=1.029-1.385, p=0.019, OR=1.535, 95% CI=1.108-2.126, p=0.010). The allele and genotype distributions of rs352140 were not significantly different between childhood-onset and adult-onset T1D and between T1D with a single islet autoantibody and T1D with multiple islet autoantibodies (p=0.603, p=0.743). rs352140 was associated with T1D susceptibility according to the recessive and additive models (p=0.015, p=0.019) but was not associated with T1D susceptibility in the dominant and overdominant models (p=0.117, p=0.928). Moreover, genotype-phenotype association analysis showed that the TT genotype of rs352140 was associated with higher fasting C-peptide levels (p=0.017). In the Han Chinese population, the TLR9 polymorphism rs352140 is associated with T1D and is a risk factor for susceptibility to T1D.