High proinsulin:C-peptide ratio identifies individuals with stage 2 type 1 diabetes at high risk for progression to clinical diagnosis and responses to teplizumab treatment.

AIMS/HYPOTHESIS: Tractable precision biomarkers to identify immunotherapy responders are lacking in type 1 diabetes. We hypothesised that proinsulin:C-peptide (PI:C) ratios, a readout of beta cell stress, could provide insight into type 1 diabetes progression and responses to immunotherapy. METHODS: In this post hoc analysis, proinsulin and C-peptide levels were determined in baseline serum samples from 63 participants with stage 2 type 1 diabetes in the longitudinal TrialNet Teplizumab Prevention Study (n=41 in the teplizumab arm; n=22 in the placebo arm). In addition, previously tested demographic, C-peptide, glucose and proinsulin data were used for the new data analyses. The ratio of intact (unprocessed) proinsulin to C-peptide was analysed and relationships with progression to stage 3 diabetes were investigated. RESULTS: Elevated baseline PI:C was strongly associated with more rapid progression of diabetes in both the placebo and teplizumab treatment groups, but teplizumab abrogated the impact of high pre-treatment PI:C on type 1 diabetes progression. Differential responses of drug treatment in those with high vs low PI:C ratios were independent of treatment effects of teplizumab on the PI:C ratio or on relevant immune cells. CONCLUSIONS/INTERPRETATION: High pre-treatment PI:C identified individuals with stage 2 type 1 diabetes who were exhibiting rapid progression to stage 3 disease and who displayed benefit from teplizumab treatment. These data suggest that readouts of active disease, such as PI:C ratio, could serve to identify optimal candidates or timing for type 1 diabetes disease-modifying therapies.

Effect of Tight Glycemic Control on Pancreatic Beta Cell Function in Newly Diagnosed Pediatric Type 1 Diabetes: A Randomized Clinical Trial.

Importance: Near normalization of glucose levels instituted immediately after diagnosis of type 1 diabetes has been postulated to preserve pancreatic beta cell function by reducing glucotoxicity. Previous studies have been hampered by an inability to achieve tight glycemic goals. Objective: To determine the effectiveness of intensive diabetes management to achieve near normalization of glucose levels on preservation of pancreatic beta cell function in youth with newly diagnosed type 1 diabetes. Design, Setting, and Participants: This randomized, double-blind, clinical trial was conducted at 6 centers in the US (randomizations from July 20, 2020, to October 13, 2021; follow-up completed September 15, 2022) and included youths with newly diagnosed type 1 diabetes aged 7 to 17 years. Interventions: Random assignment to intensive diabetes management, which included use of an automated insulin delivery system (n = 61), or standard care, which included use of a continuous glucose monitor (n = 52), as part of a factorial design in which participants weighing 30 kg or more also were assigned to receive either oral verapamil or placebo. Main Outcomes and Measures: The primary outcome was mixed-meal tolerance test-stimulated C-peptide area under the curve (a measure of pancreatic beta cell function) 52 weeks from diagnosis. Results: Among 113 participants (mean [SD] age, 11.8 [2.8] years; 49 females [43%]; mean [SD] time from diagnosis to randomization, 24 [5] days), 108 (96%) completed the trial. The mean C-peptide area under the curve decreased from 0.57 pmol/mL at baseline to 0.45 pmol/mL at 52 weeks in the intensive management group, and from 0.60 to 0.50 pmol/mL in the standard care group (treatment group difference, -0.01 [95% CI, -0.11 to 0.10]; P = .89). The mean time in the target range of 70 to 180 mg/dL, measured with continuous glucose monitoring, at 52 weeks was 78% in the intensive management group vs 64% in the standard care group (adjusted difference, 16% [95% CI, 10% to 22%]). One severe hypoglycemia event and 1 diabetic ketoacidosis event occurred in each group. Conclusions and Relevance: In youths with newly diagnosed type 1 diabetes, intensive diabetes management, which included automated insulin delivery, achieved excellent glucose control but did not affect the decline in pancreatic C-peptide secretion at 52 weeks. Trial Registration: ClinicalTrials.gov Identifier: NCT04233034.

Effect of Verapamil on Pancreatic Beta Cell Function in Newly Diagnosed Pediatric Type 1 Diabetes: A Randomized Clinical Trial.

Importance: In preclinical studies, thioredoxin-interacting protein overexpression induces pancreatic beta cell apoptosis and is involved in glucotoxicity-induced beta cell death. Calcium channel blockers reduce these effects and may be beneficial to beta cell preservation in type 1 diabetes. Objective: To determine the effect of verapamil on pancreatic beta cell function in children and adolescents with newly diagnosed type 1 diabetes. Design, Setting, and Participants: This double-blind, randomized clinical trial including children and adolescents aged 7 to 17 years with newly diagnosed type 1 diabetes who weighed 30 kg or greater was conducted at 6 centers in the US (randomized participants between July 20, 2020, and October 13, 2021) and follow-up was completed on September 15, 2022. Interventions: Participants were randomly assigned 1:1 to once-daily oral verapamil (n = 47) or placebo (n = 41) as part of a factorial design in which participants also were assigned to receive either intensive diabetes management or standard diabetes care. Main Outcomes and Measures: The primary outcome was area under the curve values for C-peptide level (a measure of pancreatic beta cell function) stimulated by a mixed-meal tolerance test at 52 weeks from diagnosis of type 1 diabetes. Results: Among 88 participants (mean age, 12.7 [SD, 2.4] years; 36 were female [41%]; and the mean time from diagnosis to randomization was 24 [SD, 4] days), 83 (94%) completed the trial. In the verapamil group, the mean C-peptide area under the curve was 0.66 pmol/mL at baseline and 0.65 pmol/mL at 52 weeks compared with 0.60 pmol/mL at baseline and 0.44 pmol/mL at 52 weeks in the placebo group (adjusted between-group difference, 0.14 pmol/mL [95% CI, 0.01 to 0.27 pmol/mL]; P = .04). This equates to a 30% higher C-peptide level at 52 weeks with verapamil. The percentage of participants with a 52-week peak C-peptide level of 0.2 pmol/mL or greater was 95% (41 of 43 participants) in the verapamil group vs 71% (27 of 38 participants) in the placebo group. At 52 weeks, hemoglobin A1c was 6.6% in the verapamil group vs 6.9% in the placebo group (adjusted between-group difference, -0.3% [95% CI, -1.0% to 0.4%]). Eight participants (17%) in the verapamil group and 8 participants (20%) in the placebo group had a nonserious adverse event considered to be related to treatment. Conclusions and Relevance: In children and adolescents with newly diagnosed type 1 diabetes, verapamil partially preserved stimulated C-peptide secretion at 52 weeks from diagnosis compared with placebo. Further studies are needed to determine the longitudinal durability of C-peptide improvement and the optimal length of therapy. Trial Registration: ClinicalTrials.gov Identifier: NCT04233034.

Beta cells in type 1 diabetes: mass and function; sleeping or dead?

Histological analysis of donor pancreases coupled with measurement of serum C-peptide in clinical cohorts has challenged the idea that all beta cells are eventually destroyed in type 1 diabetes. These findings have raised a number of questions regarding how the remaining beta cells have escaped immune destruction, whether pools of 'sleeping' or dysfunctional beta cells could be rejuvenated and whether there is potential for new growth of beta cells. In this Review, we describe histological and in vivo evidence of persistent beta cells in type 1 diabetes and discuss the limitations of current methods to distinguish underlying beta cell mass in comparison with beta cell function. We highlight that evidence for new beta cell growth in humans many years from diagnosis is limited, and that this growth may be very minimal if at all present. We review recent contributions to the debate around beta cell abnormalities contributing to the pathogenesis of type 1 diabetes. We also discuss evidence for restoration of beta cell function, as opposed to mass, in recent-onset type 1 diabetes, but highlight the absence of data supporting functional recovery in the setting of long-duration diabetes. Finally, future areas of research are suggested to help resolve the source and phenotype of residual beta cells that persist in some, but not all, people with type 1 diabetes.

Persistent elevations in circulating INS DNA among subjects with longstanding type 1 diabetes.

AIM: To evaluate whether ß cells continue to undergo death in the later stages of type 1 diabetes (T1D). MATERIALS AND METHODS: Fasting banked sera from a cross-section of 90 participants in the T1D Exchange Registry with longstanding T1D (median duration of 9 years) were analysed. Subjects were determined to be C-peptide (-) or (+) based on mixed-meal tolerance testing. Results were compared with 54 adult non-diabetic controls. Stimulated samples were assayed in a subset of subjects. Levels of unmethylated and methylated preproinsulin (INS) DNA were analysed using digital droplet PCR. RESULTS: Fasting and stimulated circulating unmethylated INS DNA levels were increased among both C-peptide (-) and C-peptide (+) subjects with longstanding T1D compared with non-diabetic controls (P < 0.01). Consistent with prior reports, unmethylated INS DNA values correlated with methylated INS DNA values, which were also elevated among T1D subjects (P < 0.001). There was wide variation in the effects of mixed-meal stimulation on DNA levels, with fasting values in the highest quartiles decreasing with stimulation (P < 0.05). CONCLUSIONS: These results could reflect ongoing ß cell death in individuals with longstanding T1D, even in the absence of detectable C-peptide production, suggesting that therapies targeting ß cell survival could be beneficial among individuals with longstanding T1D.

Associations of HbA1c with the timing of C-peptide responses during the oral glucose tolerance test at the diagnosis of type 1 diabetes.

BACKGROUND: In new onset type 1 diabetes (T1D), overall C-peptide measures such as area under the curve (AUC) C-peptide and peak C-peptide are useful for estimating the extent of ß-cell dysfunction, and for assessing responses to intervention therapy. However, measures of the timing of C-peptide responsiveness could have additional value. OBJECTIVES: We assessed the contribution of the timing of C-peptide responsiveness during oral glucose tolerance tests (OGTTs) to hemoglobin A1c (HbA1c) variation at T1D diagnosis. METHODS: We analyzed data from 85 individuals <18 years with OGTTs and HbA1c measurements at diagnosis. Overall [AUC and peak C-peptide] and timing measures [30-0 minute C-peptide (early); 60 to 120 minute C-peptide sum-30 minutes (late); 120/30 C-peptide; time to peak C-peptide] were utilized. RESULTS: At diagnosis, the mean (±SD) age was 11.2 ± 3.3 years, body mass index (BMI)-z was 0.4 ± 1.1, 51.0% were male. The average HbA1c was 43.54 ± 8.46 mmol/mol (6.1 ± 0.8%). HbA1c correlated inversely with the AUC C-peptide (P < 0.001), peak C-peptide (P < 0.001), early and late C-peptide responses (P < 0.001 each), and 120/30 C-peptide (P < 0.001). Those with a peak C-peptide occurring at ≤60 minutes had higher HbA1c values than those with peaks later (P = 0.003). HbA1c variance was better explained with timing measures added to regression models (R2 = 11.6% with AUC C-peptide alone; R2 = 20.0% with 120/30 C-peptide added; R2 = 13.7% with peak C-peptide alone, R2 = 20.4% with timing of the peak added). Similar associations were seen between the 2-hour glucose and the C-peptide measures. CONCLUSIONS: These findings show that the addition of timing measures of C-peptide responsiveness better explains HbA1c variation at diagnosis than standard measures alone.

Biomarkers of islet beta cell stress and death in type 1 diabetes.

Recent work on the pathogenesis of type 1 diabetes has led to an evolving recognition of the heterogeneity of this disease, both with regards to clinical phenotype and responses to therapies to prevent or revert diabetes. This heterogeneity not only limits efforts to accurately predict clinical disease but also is reflected in differing responses to immunomodulatory therapeutics. Thus, there is a need for robust biomarkers of beta cell health, which could provide insight into pathophysiological differences in disease course, improve disease prediction, increase the understanding of therapeutic responses to immunomodulatory interventions and identify individuals most likely to benefit from these therapies. In this review, we outline current literature, limitations and future directions for promising circulating markers of beta cell stress and death in type 1 diabetes, including markers indicating abnormal prohormone processing, circulating RNAs and circulating DNAs.

Beta cell extracellular vesicle miR-21-5p cargo is increased in response to inflammatory cytokines and serves as a biomarker of type 1 diabetes.

AIMS/HYPOTHESIS: Improved biomarkers are acutely needed for the detection of developing type 1 diabetes, prior to critical loss of beta cell mass. We previously demonstrated that elevated beta cell microRNA 21-5p (miR-21-5p) in rodent and human models of type 1 diabetes increased beta cell apoptosis. We hypothesised that the inflammatory milieu of developing diabetes may also increase miR-21-5p in beta cell extracellular vesicle (EV) cargo and that circulating EV miR-21-5p would be increased during type 1 diabetes development. METHODS: MIN6 and EndoC-ßH1 beta cell lines and human islets were treated with IL-1ß, IFN-γ and TNF-α to mimic the inflammatory milieu of early type 1 diabetes. Serum was collected weekly from 8-week-old female NOD mice until diabetes onset. Sera from a cross-section of 19 children at the time of type 1 diabetes diagnosis and 16 healthy children were also analysed. EVs were isolated from cell culture media or serum using sequential ultracentrifugation or ExoQuick precipitation and EV miRNAs were assayed. RESULTS: Cytokine treatment in beta cell lines and human islets resulted in a 1.5- to threefold increase in miR-21-5p. However, corresponding EVs were further enriched for this miRNA, with a three- to sixfold EV miR-21-5p increase in response to cytokine treatment. This difference was only partially reduced by pre-treatment of beta cells with Z-VAD-FMK to inhibit cytokine-induced caspase activity. Nanoparticle tracking analysis showed cytokines to have no effect on the number of EVs, implicating specific changes within EV cargo as being responsible for the increase in beta cell EV miR-21-5p. Sequential ultracentrifugation to separate EVs by size suggested that this effect was mostly due to cytokine-induced increases in exosome miR-21-5p. Longitudinal serum collections from NOD mice showed that EVs displayed progressive increases in miR-21-5p beginning 3 weeks prior to diabetes onset. To validate the relevance to human diabetes, we assayed serum from children with new-onset type 1 diabetes compared with healthy children. While total serum miR-21-5p and total serum EVs were reduced in diabetic participants, serum EV miR-21-5p was increased threefold compared with non-diabetic individuals. By contrast, both serum and EV miR-375-5p were increased in parallel among diabetic participants. CONCLUSIONS/INTERPRETATION: We propose that circulating EV miR-21-5p may be a promising marker of developing type 1 diabetes. Additionally, our findings highlight that, for certain miRNAs, total circulating miRNA levels are distinct from circulating EV miRNA content.

MicroRNA 21 targets BCL2 mRNA to increase apoptosis in rat and human beta cells.

AIMS/HYPOTHESIS: The role of beta cell microRNA (miR)-21 in the pathophysiology of type 1 diabetes has been controversial. Here, we sought to define the context of beta cell miR-21 upregulation in type 1 diabetes and the phenotype of beta cell miR-21 overexpression through target identification. METHODS: Islets were isolated from NOD mice and mice treated with multiple low doses of streptozotocin, as a mouse model of diabetes. INS-1 832/13 beta cells and human islets were treated with IL-1ß, IFN-γ and TNF-α to mimic the milieu of early type 1 diabetes. Cells and islets were transfected with miR-21 mimics or inhibitors. Luciferase assays and polyribosomal profiling (PRP) were performed to define miR-21-target interactions. RESULTS: Beta cell miR-21 was increased in in vivo models of type 1 diabetes and cytokine-treated cells/islets. miR-21 overexpression decreased cell count and viability, and increased cleaved caspase 3 levels, suggesting increased cell death. In silico prediction tools identified the antiapoptotic mRNA BCL2 as a conserved miR-21 target. Consistent with this, miR-21 overexpression decreased BCL2 transcript and B cell lymphoma 2 (BCL2) protein production, while miR-21 inhibition increased BCL2 protein levels and reduced cleaved caspase 3 levels after cytokine treatment. miR-21-mediated cell death was abrogated in 828/33 cells, which constitutively overexpress Bcl2. Luciferase assays suggested a direct interaction between miR-21 and the BCL2 3' untranslated region. With miR-21 overexpression, PRP revealed a shift of the Bcl2 message towards monosome-associated fractions, indicating inhibition of Bcl2 translation. Finally, overexpression in dispersed human islets confirmed a reduction in BCL2 transcripts and increased cleaved caspase 3 production. CONCLUSIONS/INTERPRETATION: In contrast to the pro-survival role reported in other systems, our results demonstrate that miR-21 increases beta cell death via BCL2 transcript degradation and inhibition of BCL2 translation.

Biomarkers of ß-Cell Stress and Death in Type 1 Diabetes.

The hallmark of type 1 diabetes (T1D) is a decline in functional ß-cell mass arising as a result of autoimmunity. Immunomodulatory interventions at disease onset have resulted in partial stabilization of ß-cell function, but full recovery of insulin secretion has remained elusive. Revised efforts have focused on disease prevention through interventions administered at earlier disease stages. To support this paradigm, there is a parallel effort ongoing to identify circulating biomarkers that have the potential to identify stress and death of the islet ß-cells. Whereas no definitive biomarker(s) have been fully validated, several approaches hold promise that T1D can be reliably identified in the pre-symptomatic phase, such that either ß-cell preservation or immunomodulatory agents might be employed in at-risk populations. This review summarizes the most promising protein- and nucleic acid-based biomarkers discovered to date and reviews the context in which they have been studied.

Human adipose-derived stromal/stem cells protect against STZ-induced hyperglycemia: analysis of hASC-derived paracrine effectors.

Adipose-derived stromal/stem cells (ASCs) ameliorate hyperglycemia in rodent models of islet transplantation and autoimmune diabetes, yet the precise human ASC (hASC)-derived factors responsible for these effects remain largely unexplored. Here, we show that systemic administration of hASCs improved glucose tolerance, preserved ß cell mass, and increased ß cell proliferation in streptozotocin-treated nonobese diabetic/severe combined immunodeficient mice. Coculture experiments combining mouse or human islets with hASCs demonstrated that islet viability and function were improved by hASCs following prolonged culture or treatment with proinflammatory cytokines. Analysis of hASC-derived factors revealed vascular endothelial growth factor and tissue inhibitor of metalloproteinase 1 (TIMP-1) to be highly abundant factors secreted by hASCs. Notably, TIMP-1 secretion increased in the presence of islet stress from cytokine treatment, while TIMP-1 blockade was able to abrogate in vitro prosurvival effects of hASCs. Following systemic administration by tail vein injection, hASCs were detected in the pancreas and human TIMP-1 was increased in the serum of injected mice, while recombinant TIMP-1 increased viability in INS-1 cells treated with interleukin-1beta, interferon-gamma, and tumor necrosis factor alpha. In aggregate, our data support a model whereby factors secreted by hASCs, such as TIMP-1, are able to mitigate against ß cell death in rodent and in vitro models of type 1 diabetes through a combination of local paracrine as well as systemic effects.

Proinflammatory stress activates neutral sphingomyelinase 2 based generation of a ceramide-enriched ß cell EV subpopulation.

ß cell extracellular vesicles (EVs) play a role as paracrine effectors in islet health, yet mechanisms connecting ß cell stress to changes in EV cargo and potential impacts on diabetes remain poorly defined. We hypothesized that ß cell inflammatory stress engages neutral sphingomyelinase 2 (nSMase2)-dependent EV formation pathways, generating ceramide-enriched EVs that could impact surrounding ß cells. Consistent with this, proinflammatory cytokine treatment of INS-1 ß cells and human islets concurrently increased ß cell nSMase2 and ceramide expression, as well as EV ceramide staining. Direct chemical activation or genetic knockdown of nSMase2, or treatment with a GLP-1 receptor agonist also modulated cellular and EV ceramide. Small RNA sequencing of ceramide-enriched EVs identified a distinct set of miRNAs linked to ß cell function and identity. Coculture experiments using CD9-GFP tagged INS-1 cell EVs demonstrated that either cytokine treatment or chemical nSMase2 activation increased EV transfer to recipient cells. Children with recent-onset T1D showed no abnormalities in circulating ceramide-enriched EVs, suggesting a localized, rather than systemic phenomenon. These findings highlight nSMase2 as a regulator of ß cell EV cargo and identify ceramide-enriched EV populations as a contributor to EV-related paracrine signaling under conditions of ß cell inflammatory stress. Article Highlights: a. Why did we undertake this study?: Mechanisms connecting ß cell stress to changes in extracellular vesicle (EV) cargo and potential impacts on diabetes are poorly defined.b. What is the specific question we wanted to answer?: Does ß cell inflammatory stress engage neutral sphingomyelinase 2 (nSMase2)-dependent EV formation pathways to generate ceramide-enriched EVs.c. What did we find?: Proinflammatory cytokine treatment of ß cells increased ß cell ceramide expression, along with EV ceramide in part via increases in nSMase2. Ceramide-enriched EVs housed a distinct set of miRNAs linked to insulin signaling. Both cytokine treatment and nSMase2 activation increase EV transfer to other ß cells.d. What are the implications of our findings?: Our findings highlight nSMase2 as a regulator of ß cell EV cargo and identify ceramide-enriched EV populations as a contributor to EV-related paracrine signaling under conditions of ß cell inflammatory stress.

Comparisons of Metabolic Measures to Predict T1D vs Detect a Preventive Treatment Effect in High-Risk Individuals.

CONTEXT: Metabolic measures are frequently used to predict type 1 diabetes (T1D) and to understand effects of disease-modifying therapies. OBJECTIVE: Compare metabolic endpoints for their ability to detect preventive treatment effects and predict T1D. METHODS: Six-month changes in metabolic endpoints were assessed for (1) detecting treatment effects by comparing placebo and treatment arms from the randomized controlled teplizumab prevention trial, a multicenter clinical trial investigating 14-day intravenous teplizumab infusion and (2) predicting T1D in the TrialNet Pathway to Prevention natural history study. For each metabolic measure, t-Values from t tests for detecting a treatment effect were compared with chi-square values from proportional hazards regression for predicting T1D. Participants in the teplizumab prevention trial and participants in the Pathway to Prevention study selected with the same inclusion criteria used for the teplizumab trial were studied. RESULTS: Six-month changes in glucose-based endpoints predicted diabetes better than C-peptide-based endpoints, yet the latter were better at detecting a teplizumab effect. Combined measures of glucose and C-peptide were more balanced than measures of glucose alone or C-peptide alone for predicting diabetes and detecting a teplizumab effect. CONCLUSION: The capacity of a metabolic endpoint to detect a treatment effect does not necessarily correspond to its accuracy for predicting T1D. However, combined glucose and C-peptide endpoints appear to be effective for both predicting diabetes and detecting a response to immunotherapy. These findings suggest that combined glucose and C-peptide endpoints should be incorporated into the design of future T1D prevention trials.

Pediatric Endocrine Society Statement on Considerations for Use of Teplizumab (Tzield™) in Clinical Practice.

Teplizumab (TzieldTM, Provention Bio), a monoclonal antibody directed at T-cell marker CD3, is the first medication approved by the FDA to delay progression from stage 2 to stage 3 type 1 diabetes. To date, the overwhelming majority of pediatric endocrinologists do not have experience using immunotherapeutics and seek guidance on the use of teplizumab in clinical practice. To address this need, the Pediatric Endocrine Society (PES) Diabetes Special Interest Group (Diabetes SIG) and Drug and Therapeutics Committee assembled a task force to review clinical trial data and solicit expert recommendations on the approach to teplizumab infusions. We present considerations on all aspects of teplizumab administration, utilizing evidence where possible and providing a spectrum of expert opinions on unknown aspects. We discuss patient selection and prescreening, highlighting the safety and considerations for monitoring and treatment of side effects. We propose a schedule of events, a protocol for administration, and discuss practice management aspects. We advocate for the need for further long-term systematic surveillance studies to continue evaluating the efficacy and safety of teplizumab.

Early Metabolic Endpoints Identify Persistent Treatment Efficacy in Recent-Onset Type 1 Diabetes Immunotherapy Trials.

OBJECTIVE: Mixed-meal tolerance test-stimulated area under the curve (AUC) C-peptide at 12-24 months represents the primary end point for nearly all intervention trials seeking to preserve ß-cell function in recent-onset type 1 diabetes. We hypothesized that participant benefit might be detected earlier and predict outcomes at 12 months posttherapy. Such findings would support shorter trials to establish initial efficacy. RESEARCH DESIGN AND METHODS: We examined data from six Type 1 Diabetes TrialNet immunotherapy randomized controlled trials in a post hoc analysis and included additional stimulated metabolic indices beyond C-peptide AUC. We partitioned the analysis into successful and unsuccessful trials and analyzed the data both in the aggregate as well as individually for each trial. RESULTS: Among trials meeting their primary end point, we identified a treatment effect at 3 and 6 months when using C-peptide AUC (P = 0.030 and P < 0.001, respectively) as a dynamic measure (i.e., change from baseline). Importantly, no such difference was seen in the unsuccessful trials. The use of C-peptide AUC as a 6-month dynamic measure not only detected treatment efficacy but also suggested long-term C-peptide preservation (R2 for 12-month C-peptide AUC adjusted for age and baseline value was 0.80, P < 0.001), and this finding supported the concept of smaller trial sizes down to 54 participants. CONCLUSIONS: Early dynamic measures can identify a treatment effect among successful immune therapies in type 1 diabetes trials with good long-term prediction and practical sample size over a 6-month period. While external validation of these findings is required, strong rationale and data exist in support of shortening early-phase clinical trials.

Inhibition of the eukaryotic initiation factor-2-α kinase PERK decreases risk of autoimmune diabetes in mice.

Preventing the onset of autoimmune type 1 diabetes (T1D) is feasible through pharmacological interventions that target molecular stress-responsive mechanisms. Cellular stresses, such as nutrient deficiency, viral infection, or unfolded proteins, trigger the integrated stress response (ISR), which curtails protein synthesis by phosphorylating eIF2α. In T1D, maladaptive unfolded protein response (UPR) in insulin-producing beta cells renders these cells susceptible to autoimmunity. We found that inhibition of the eIF2α kinase PERK, a common component of the UPR and ISR, reversed the mRNA translation block in stressed human islets and delayed the onset of diabetes, reduced islet inflammation, and preserved ß cell mass in T1D-susceptible mice. Single-cell RNA sequencing of islets from PERK-inhibited mice showed reductions in the UPR and PERK signaling pathways and alterations in antigen processing and presentation pathways in ß cells. Spatial proteomics of islets from these mice showed an increase in the immune checkpoint protein PD-L1 in ß cells. Golgi membrane protein 1, whose levels increased following PERK inhibition in human islets and EndoC-ßH1 human ß cells, interacted with and stabilized PD-L1. Collectively, our studies show that PERK activity enhances ß cell immunogenicity, and inhibition of PERK may offer a strategy to prevent or delay the development of T1D.

Inhibition of the Eukaryotic Initiation Factor-2-α Kinase PERK Decreases Risk of Autoimmune Diabetes in Mice.

Preventing the onset of autoimmune type 1 diabetes (T1D) is feasible through pharmacological interventions that target molecular stress-responsive mechanisms. Cellular stresses, such as nutrient deficiency, viral infection, or unfolded proteins, trigger the integrated stress response (ISR), which curtails protein synthesis by phosphorylating eIF2α. In T1D, maladaptive unfolded protein response (UPR) in insulin-producing ß cells renders these cells susceptible to autoimmunity. We show that inhibition of the eIF2α kinase PERK, a common component of the UPR and ISR, reverses the mRNA translation block in stressed human islets and delays the onset of diabetes, reduces islet inflammation, and preserves ß cell mass in T1D-susceptible mice. Single-cell RNA sequencing of islets from PERK-inhibited mice shows reductions in the UPR and PERK signaling pathways and alterations in antigen processing and presentation pathways in ß cells. Spatial proteomics of islets from these mice shows an increase in the immune checkpoint protein PD-L1 in ß cells. Golgi membrane protein 1, whose levels increase following PERK inhibition in human islets and EndoC-ßH1 human ß cells, interacts with and stabilizes PD-L1. Collectively, our studies show that PERK activity enhances ß cell immunogenicity, and inhibition of PERK may offer a strategy to prevent or delay the development of T1D.

Islet autoantibodies as precision diagnostic tools to characterize heterogeneity in type 1 diabetes: a systematic review.

BACKGROUND: Islet autoantibodies form the foundation for type 1 diabetes (T1D) diagnosis and staging, but heterogeneity exists in T1D development and presentation. We hypothesized that autoantibodies can identify heterogeneity before, at, and after T1D diagnosis, and in response to disease-modifying therapies. METHODS: We systematically reviewed PubMed and EMBASE databases (6/14/2022) assessing 10 years of original research examining relationships between autoantibodies and heterogeneity before, at, after diagnosis, and in response to disease-modifying therapies in individuals at-risk or within 1 year of T1D diagnosis. A critical appraisal checklist tool for cohort studies was modified and used for risk of bias assessment. RESULTS: Here we show that 152 studies that met extraction criteria most commonly characterized heterogeneity before diagnosis (91/152). Autoantibody type/target was most frequently examined, followed by autoantibody number. Recurring themes included correlations of autoantibody number, type, and titers with progression, differing phenotypes based on order of autoantibody seroconversion, and interactions with age and genetics. Only 44% specifically described autoantibody assay standardization program participation. CONCLUSIONS: Current evidence most strongly supports the application of autoantibody features to more precisely define T1D before diagnosis. Our findings support continued use of pre-clinical staging paradigms based on autoantibody number and suggest that additional autoantibody features, particularly in relation to age and genetic risk, could offer more precise stratification. To improve reproducibility and applicability of autoantibody-based precision medicine in T1D, we propose a methods checklist for islet autoantibody-based manuscripts which includes use of precision medicine MeSH terms and participation in autoantibody standardization workshops.

Islet autoantibodies are markers found in the blood when insulin-producing cells in the pancreas become damaged and can be used to predict future development of type 1 diabetes. We evaluated published literature to determine whether characteristics of islet antibodies (type, levels, numbers) could improve prediction and help understand differences in how individuals with type 1 diabetes respond to treatments. We found existing evidence shows that islet autoantibody type and number are most useful to predict disease progression before diagnosis. In addition, the age when islet autoantibodies first appear strongly influences rate of progression. These findings provide important information for patients and care providers on how islet autoantibodies can be used to understand future type 1 diabetes development and to identify individuals who have the potential to benefit from intervention or prevention therapy.

Divergent compensatory responses to high-fat diet between C57BL6/J and C57BLKS/J inbred mouse strains.

Impaired glucose tolerance (IGT) and type 2 diabetes (T2DM) are polygenic disorders with complex pathophysiologies; recapitulating them with mouse models is challenging. Despite 70% genetic homology, C57BL/6J (BL6) and C57BLKS/J (BLKS) inbred mouse strains differ in response to diet- and genetic-induced obesity. We hypothesized these differences would yield insight into IGT and T2DM susceptibility and response to pharmacological therapies. To this end, male 8-wk-old BL6 and BLKS mice were fed normal chow (18% kcal from fat), high-fat diet (HFD; 42% kcal from fat), or HFD supplemented with the PPARγ agonist pioglitazone (PIO; 140 mg PIO/kg diet) for 16 wk. Assessments of body composition, glucose homeostasis, insulin production, and energy metabolism, as well as histological analyses of pancreata were undertaken. BL6 mice gained weight and adiposity in response to HFD, leading to peripheral insulin resistance that was met with increased ß-cell proliferation and insulin production. By contrast, BLKS mice responded to HFD by restricting food intake and increasing activity. These behavioral responses limited weight gain and protected against HFD-induced glucose intolerance, which in this strain was primarily due to ß-cell dysfunction. PIO treatment did not affect HFD-induced weight gain in BL6 mice, and decreased visceral fat mass, whereas in BLKS mice PIO increased total fat mass without improving visceral fat mass. Differences in these responses to HFD and effects of PIO reflect divergent human responses to a Western lifestyle and underscore the careful consideration needed when choosing mouse models of diet-induced obesity and diabetes treatment.

Screening and Prevention of Type 1 Diabetes: Where Are We?

A diagnosis of type 1 diabetes (T1D) and the subsequent requirement for exogenous insulin treatment is associated with considerable acute and chronic morbidity and a substantial effect on patient quality of life. Importantly, a large body of work suggests that early identification of presymptomatic T1D can accurately predict clinical disease, and when paired with education and monitoring, can yield improved health outcomes. Furthermore, a growing cadre of effective disease-modifying therapies provides the potential to alter the natural history of early stages of T1D. In this mini review, we highlight prior work that has led to the current landscape of T1D screening and prevention, as well as challenges and next steps moving into the future of these rapidly evolving areas of patient care.