Type 1 diabetes is a polygenic disease that results in an autoimmune response directed against insulin-producing beta cells.
is a known high-risk type 1 diabetes associated gene expressed in both ...immune- and pancreatic beta cells, but how genes affect the development of autoimmune diabetes is largely unknown. We employed CRISPR/Cas9 technology to generate a functional knockout of
in human pluripotent stem cells (hPSC) followed by differentiating stem-cell-derived beta-like cells (sBC) and detailed phenotypical analyses. The differentiation efficiency of
knockout (PTPN2 KO) sBC is comparable to wild-type (WT) control sBC. Global transcriptomics and protein assays revealed the increased expression of HLA Class I molecules in PTPN2 KO sBC at a steady state and upon exposure to proinflammatory culture conditions, indicating a potential for the increased immune recognition of human beta cells upon differential
expression. sBC co-culture with autoreactive preproinsulin-reactive T cell transductants confirmed increased immune stimulations by PTPN2 KO sBC compared to WT sBC. Taken together, our results suggest that the dysregulation of
expression in human beta cell may prime autoimmune T cell reactivity and thereby contribute to the development of type 1 diabetes.
Modeling the course of C-peptide decline in autoantibody (Ab) positive individuals is important for type 1 diabetes (T1D) prediction and implementation of T1D prevention trials. Single nucleotide ...polymorphisms in TCF7L2, JAZF1, SLC30A8, INS, PTPRK, G6CP2, CLEC16, PTPN22 and HLA genes are associated with persistent C-peptide at or after T1D diagnosis. We sought to determine whether 12 SNPs in these genes and the T1D genetic risk score-2 (GRS2) can predict C-peptide trajectory before diagnosis of T1D. We studied Ab positive at-risk participants in the TrialNet Pathway to Prevention Study who had ImmunoChip data (N=1217, age at initial screen (mean±SD) 16.1±12.7 years, 51.5% female, 81.0% non-Hispanic white) . Over a mean follow up of 3.4±2. years, 255 (21.0%) developed multiple Ab and 336 (27.6%) developed clinical T1D. We analyzed the influence of these 12 SNPs and the T1D GRS2 on C-peptide AUC during progression from single to multiple Abs, from single Ab to clinical T1D, and from multiple Abs to clinical T1D. Analyses were adjusted for baseline C-peptide AUC, age, glucose AUC, BMI Z-score and HbA1c; the presence of high-risk HLA haplotypes (DR3 and DR4-DQ8) ; and the first 3 principal components. The type 2 diabetes (T2D) -associated TCF7L2 rs7901695 and rs4506565 SNPs were significantly associated with higher C-peptide AUC during progression from multiple Abs to T1D (p<0.04) and neared significance for the single-to-multiple Ab transition (p=0.05) . Additionally, lower T1D GRS2 was significantly associated with higher C-peptide AUC during progression from multiple Abs to T1D (p=0.01) . We observed trend associations of lower C-peptide AUC with JAZF1 SNP rs864745 in both single Ab-to-T1D and multiple Ab-to-T1D progression (both p=0.06) , and with SNPs in SLC30A8 and INS in multiple Abs to T1D (p=0.and 0.08, respectively) .
In conclusion, T2D-associated SNPs in the TCF7L2 gene and lower T1D GRS2 predict higher C-peptide particularly in progression from multiple Abs to clinical T1D.
Disclosure
T.M.Triolo: None. M.J.Redondo: Advisory Panel; Provention Bio, Inc. H.M.Parikh: None. M.Tosur: Advisory Panel; Provention Bio, Inc. P.Gottlieb: Advisory Panel; Janssen Research & Development, LLC, ViaCyte, Inc., Other Relationship; IM Therapeutics, Research Support; Caladrius Biosciences, Inc., Immune Tolerance Network, National Institute of Diabetes and Digestive and Kidney Diseases, Novo Nordisk, Precigen, Inc., Tolerion, Inc. R.A.Oram: Consultant; Janssen Research & Development, LLC, Research Support; Randox R & D. S.Onengut-gumuscu: None. J.Krischer: None. S.S.Rich: None. A.Steck: None.
Funding
NIH K12 DK094712NIH RDK121843NIH RDK124395
While continuous glucose monitors (CGMs), insulin pumps, and hybrid closed-loop (HCL) systems each improve glycemic control in type 1 diabetes, it is unclear how the use of these technologies impacts ...real-world pediatric care.
We found 1,455 patients aged <22 years, with type 1 diabetes duration >3 months, and who had data from a single center in between both 2016-2017 (n = 2,827) and 2020-2021 (n = 2,731). Patients were grouped by multiple daily injections or insulin pump, with or without an HCL system, and using a blood glucose monitor or CGM. Glycemic control was compared using linear mixed-effects models adjusting for age, diabetes duration, and race/ethnicity.
CGM use increased from 32.9 to 75.3%, and HCL use increased from 0.3 to 27.9%. Overall A1C decreased from 8.9 to 8.6% (P < 0.0001).
Adoption of CGM and HCL was associated with decreased A1C, suggesting promotion of these technologies may yield glycemic benefits.
Stem cell-derived β-like cells (sBC) carry the promise of providing an abundant source of insulin-producing cells for use in cell replacement therapy for patients with diabetes, potentially allowing ...widespread implementation of a practical cure. To achieve their clinical promise, sBC need to function comparably with mature adult β-cells, but as yet they display varying degrees of maturity. Indeed, detailed knowledge of the events resulting in human β-cell maturation remains obscure. Here we show that sBC spontaneously self-enrich into discreet islet-like cap structures within in vitro cultures, independent of exogenous maturation conditions. Multiple complementary assays demonstrate that this process is accompanied by functional maturation of the self-enriched sBC (seBC); however, the seBC still contain distinct subpopulations displaying different maturation levels. Interestingly, the surface protein ENTPD3 (also known as nucleoside triphosphate diphosphohydrolase-3 NDPTase3) is a specific marker of the most mature seBC population and can be used for mature seBC identification and sorting. Our results illuminate critical aspects of in vitro sBC maturation and provide important insights toward developing functionally mature sBC for diabetes cell replacement therapy.
Type 1 diabetes (T1D) is an autoimmune disease marked by permanent loss of insulin-producing pancreatic β cells. Genome wide association studies have identified protein tyrosine non receptor type 2 ...(PTPN2) as a high-risk T1D gene. PTPN2 has been classically implicated in immune cell function, but is expressed in T cells, B cells, and in pancreatic β cells. Mice with a β cell specific knock out (KO) of ptpn2 exhibit impaired function and increased susceptibility to stress induced β cell death. We hypothesized that altered PTPN2 expression in pancreatic beta cells may contribute to T1D disease development. In order to study PTPN2 in the human context we generated CRISPR/Cas9 mediated clonal PTPN2 knock out (KO) hPSCs, abolishing the functional domain of PTPN2. PTPN2 KO and WT hPSCs were differentiated into functional stem cell derived beta-like cells (sBCs) using our published protocol without significant differences in key developmental markers or insulin content. Compared to WT sBC, PTPN2 KO sBCs at steady state and under T1D stress conditions show increased expression of HLA Class I molecules important in T cell recognition. To investigate the interaction of KO or WT sBCs with diabetogenic T cells we employed an HLA-peptide-TCR matched coculture system we recently established. Using this system, we observed increased stimulation of diabetogenic TCR T cell transductants by KO sBC compared to WT. Our data provide evidence for a potential mechanism by which PTPN2, a known T1D high-risk gene may contribute to an immunogenic phenotype of β cells. Our findings suggest that dysregulation of PTPN2 expression contributes to an autoimmune response towards human β cells thus contributing to the pathogenesis of type 1 diabetes.
Disclosure
J. Q. Matuschek: None. H. A. Russ: Consultant; Eli Lilly and Company, Sigilon Therapeutics, Inc. T. M. Triolo: None. A. W. Michels: Employee; ImmunoMolecular Therapeutics, Stock/Shareholder; ImmunoMolecular Therapeutics. K. Mcdaniel: None. M. S. Hansen: None. S. Williams: None. R. Castro-gutierrez: None. A. Shilleh: None.
Funding
NIH: K12DK094712
Autoimmune loss of beta-cell function (measured by C-peptide) is the hallmark of type 1 diabetes (T1D) targeted by interventions that aim to prevent T1D or its progression after onset. We sought to ...determine whether T1D genetic risk score-2 (T1D-GRS2) and single nucleotide polymorphisms (SNPs) that have been previously associated with C-peptide preservation after T1D diagnosis (e.g., SNPs in CLEC16A, G6CP2, INS, JAZF1, PTPN22, SLC30A8 and TCF7L2) influence C-peptide levels before diagnosis.
We studied islet autoantibody (Ab)-positive participants in the TrialNet Pathway to Prevention Study who had T1DExomeChip data and assessed the influence of these 12 SNPs and the T1D-GRS2 on area under the curve (AUC) C-peptide levels during oral glucose tolerance tests conducted between 0-9 months prior to the diagnosis of T1D. Participants (n=702) had a mean age of 13.5±10.3 years, 47% were female, mean BMI was 20.7±6.0 kg/m2, and mean HbA1c 5.4±0.4%. The T1D high-risk HLA-DR3-DQ2 haplotype was present in 47% and the high-risk HLA-DR4-DQ8 haplotype was present in 67% of participants. We performed univariate and multivariate analyses adjusting for BMI, age, sex, number of positive Ab, and the first 3 principal components of ancestry.
A higher T1D-GRS2 was associated with lower C-peptide AUC 0-9 months prior to T1D diagnosis in univariate (β=-0.06, P<0.0001) and multivariate (β=-0.03, p=0.008) analyses. Participants with the JAZF1 rs864745 G allele had lower C-peptide AUC 0-9 months prior to T1D diagnosis in univariate (β=-0.10, p=0.003) and multivariate (β=-0.05, p=0.047) analysis.
In conclusion, the JAZF1 rs864745 G allele (which has also been associated with type 2 diabetes risk) and higher T1D-GRS2 predict lower C-peptide AUC prior to the diagnosis of T1D. Studies on their effect on response to trials to prevent or delay T1D onset are warranted.
Disclosure
T. M. Triolo: None. S. S. Rich: None. A. Steck: None. M. J. Redondo: None. H. M. Parikh: None. M. Tosur: Advisory Panel; Provention Bio, Inc. L. A. Ferrat: Consultant; Johnson & Johnson. L. You: None. P. Gottlieb: Advisory Panel; ViaCyte, Inc., Board Member; ImmunoMolecular Therapeutics, Research Support; Imcyse, Hemsley Charitable Trust, Novartis, National Institute of Diabetes and Digestive and Kidney Diseases, Precigen, Inc., Dompé, Nova Pharmaceuticals, Provention Bio, Inc. R. A. Oram: Consultant; Janssen Research & Development, LLC, Research Support; Randox R & D. S. Onengut-gumuscu: None. J. Krischer: None.
Funding
National Institutes of Health (R01DK121843, R01DK124395)
This multicenter prospective cohort study compared pancreas volume as assessed by MRI, metabolic scores derived from oral glucose tolerance testing (OGTT), and a combination of pancreas volume and ...metabolic scores for predicting progression to stage 3 type 1 diabetes (T1D) in individuals with multiple diabetes-related autoantibodies.
Pancreas MRI was performed in 65 multiple autoantibody-positive participants enrolled in the Type 1 Diabetes TrialNet Pathway to Prevention study. Prediction of progression to stage 3 T1D was assessed using pancreas volume index (PVI), OGTT-derived Index60 score and Diabetes Prevention Trial-Type 1 Risk Score (DPTRS), and a combination of PVI and DPTRS.
PVI, Index60, and DPTRS were all significantly different at study entry in 11 individuals who subsequently experienced progression to stage 3 T1D compared with 54 participants who did not experience progression (P < 0.005). PVI did not correlate with metabolic testing across individual study participants. PVI declined longitudinally in the 11 individuals diagnosed with stage 3 T1D, whereas Index60 and DPTRS increased. The area under the receiver operating characteristic curve for predicting progression to stage 3 from measurements at study entry was 0.76 for PVI, 0.79 for Index60, 0.79 for DPTRS, and 0.91 for PVI plus DPTRS.
These findings suggest that measures of pancreas volume and metabolism reflect distinct components of risk for developing stage 3 type 1 diabetes and that a combination of these measures may provide superior prediction than either alone.
Biomarkers are needed to characterize heterogeneity within populations at risk for type 1 diabetes (T1D). The ratio of proinsulin to C-peptide (PI:C ratio), a biomarker of beta cell dysfunction, has ...been associated with progression to T1D, but relationships between PI:C ratios and autoantibody (Ab) type and number have not been explored. We sought to characterize PI:C ratios in multiple islet Ab positive, single Ab positive and Ab negative relatives of individuals with T1D.
We measured PI:C ratios and Abs with both electrochemiluminescence (ECL) assays (ECL-IAA, ECL-GADA and ECL-IA2)and radio-binding (RBA) assays (mIAA, GADA, IA2A and ZnT8A) in 98 relatives of persons with T1D followed in the Pathway to Prevention Study at the Barbara Davis Center. Of these subjects, 31 were multiple Ab positive, 37 were single Ab positive and 22 were Ab negative at the most recent visit. Eight subjects progressed to T1D over a mean follow-up of 5.5±3.6 years. In cross-sectional analyses, there were no significant differences in PI:C ratios between T1D and/or multiple Ab positive subjects (4.16±4.06) compared to single Ab positive subjects (4.08±4.34) and negative Ab subjects (3.72±3.78) (p=0.92) overall or after adjusting for age, sex and BMI. Higher PI:C ratios were associated with ECL-IA2A (p=0.03) and ECL-IAA (p=0.03) levels, but not with mIAA, GADA, ECL-GADA, IA2A nor ZnT8A levels. In mixed-effects longitudinal models, the trajectories of PI:C ratio over time were not significantly different between the 4 groups, overall or after adjusting for sex, age, and BMI.
In conclusion, higher PI:C ratios were associated with ECL-IAA and ECL-IA2A levels, which have previously been associated with progression to T1D.
Disclosure
T.M. Triolo: None. L. Pyle: None. S. Seligova: None. L. Yu: None. K. Simmons: None. P. Gottlieb: Consultant; Self; Bristol-Myers Squibb Company, Eli Lilly and Company, Kamada, Tolerion, Inc. Research Support; Self; Intrexon, Janssen Pharmaceuticals, Inc., Mercia/NovaImmune, National Institute of Diabetes and Digestive and Kidney Diseases, Novo Nordisk Inc. Stock/Shareholder; Self; IM Therapeutics. Other Relationship; Self; Viacyte, Inc. C. Evans-Molina: None. A. Steck: None.
Funding
American Diabetes Association (1-14-CD-17 to A.S.)
The TrialNet OI prevention trial (TN07) with T1D as an endpoint showed no effect. However, in a smaller trial run in parallel with TN07 (termed secondary stratum 1), in which all participants had low ...first-phase insulin release, a statistically significant delay in T1D onset was found. Since trials with T1D as an endpoint take years to complete, we aimed to determine if combination C-peptide and glucose markers could identify a therapeutic benefit after 12 months of OI in this high-risk population. All participants were at-risk relatives with multiple autoantibodies including mIAA and normal glucose tolerance (n=40 with full data). The Figure shows changes in glucose and C-peptide response curves and their centroids (central points). Glucose rose and C-peptide declined in the placebo group compared to a minimal glucose rise with an increase of C-peptide in the OI group. Change from baseline to 1 year in the centroid ratio (C-peptide/glucose) differed significantly between groups (p=0.037 after adjustments for age, BMI, and baseline C-peptide and glucose). The AUC C-peptide/AUC glucose ratio and Index60 did not differ (both p=0.108). In conclusion, the findings support a positive effect of OI on combined glucose and C-peptide endpoints in high-risk individuals. These measures appear to detect differences in a shorter time than the standard T1D endpoint.
Type 2 diabetes (T2DM), historically an adult disease, is now increasingly prevalent in obese youth. Poor diet and increased sedentary behavior contribute to the increasing rates of obesity in youth, ...yet not all obese children develop T2DM. In general, T2DM is characterized by both insulin resistance (IR) and pancreatic beta-cell insufficiency. In children, IR is related to elevated body mass index (BMI) and pubertal hormones, along with abnormal fat partitioning, elevated free fatty acids, inflammation, and/or mitochondrial dysfunction. Hyperglycemia and T2DM develop when the pancreas cannot match the increased insulin demands resulting from IR. Unique to youth, IR varies with stage of pubertal development, and some children may have resolution of hyperglycemia post-puberty once the IR of puberty resolves. Further understanding of IR, the progression to T2DM in youth, and later outcomes as adults will help direct future therapies and interventions for youth at risk.
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