bluuebunny/crossref_metadata_2025_split huggingface dataset:
203-LB: Boosted Beta-Cell Function with Selective Deletion of the Adaptor Protein Mig6
Authors: BAUER BRANDON M. , BLOOM-SALDANA ELIZABETH A. , IRIMIA-DOMINGUEZ JOSE M. , FUEGER PATRICK T. 
Published: June 2021

Type 1 and type 2 diabetes (T1D and T2D) are characterized by absolute and relative insulin deficiency, respectively. Thus, fortifying functional beta cell mass is essential for preventing or reversing either form of diabetes. We have investigated the impact of the adaptor protein mitogen inducible gene 6 (Mig6), a feedback inhibitor of epidermal growth factor receptor (EGFR) signaling induced in the diabetic milieu, on functional beta cell mass in the context of T1D and T2D. Given the importance of EGFR signaling in establishing and maintaining functional beta cell mass, we hypothesized that a selective loss of Mig6 in beta cells would increase functional beta cell mass. To this end, we generated mice lacking Mig6 in beta cells (BKO) using Mig6 floxed and Ins1-Cre knock-in mice and conducted extensive phenotyping, including quantifying beta cell function in vivo with hyperglycemic clamps. Compared to control littermates (CON), BKO mice had comparable beta cell mass, glucose tolerance, and post-prandial blood glucose or insulin concentrations when fed a standard chow diet. Mice underwent surgical catheterization of a carotid artery and jugular vein, and were allowed to recover for 4 days. Following a 5-h fast, mice were administered a primed and subsequent variable glucose infusion designed to clamp blood glucose at 15 mM (270 mg/dl). Target glycemia was achieved by 60 min and remained constant for the duration of the experiment. During the clamp, blood glucose or glucose infusion rates were not different between groups. Whereas beta cell mass was not different between groups, BKO had enhanced beta cell function in vivo, as exhibited by increased insulin secretion; compared to CON, the cumulative circulating insulin during the clamp in BKO was substantially larger (AUC: 340 ± 24 vs. 545 ± 70 ng/ml*120 min). Thus, a loss of Mig6 in beta cells enhances functional beta cell mass by increasing beta cell insulin secretory capacity in vivo. Therefore, Mig6 should be considered as a therapeutic target for diabetes.

Disclosure
B. M. Bauer: None. E. A. Bloom-saldana: None. J. M. Irimia-dominguez: None. P. T. Fueger: Consultant; Self; Protomer Technologies.

Funding
National Institutes of Health (R01DK099311)
204-LB: GADD45b Regulates Hepatic Gluconeogenesis via Modulating the Protein Stability of FoxO1
Authors: KIM HYUNMI 
Published: June 2021

Increased hepatic gluconeogenesis is one of the main contributors to the development of type 2 diabetes. Recently, it has been reported that growth arrest and DNA damage-inducible 45 beta (GADD45β) is induced under both fasting and high-fat diet (HFD) conditions that stimulate hepatic gluconeogenesis. Here, this study aimed to establish the molecular mechanisms underlying the novel role of GADD45β in hepatic gluconeogenesis. Both whole-body knockout (KO) mice and adenovirus-mediated knockdown (KD) mice of GADD45β exhibited decreased hepatic gluconeogenic gene expression concomitant with reduced blood glucose levels under fasting and HFD conditions, but showed a more pronounced effect in GADD45β KD mice. Further, in primary hepatocytes, GADD45β KD reduced glucose output, whereas GADD45β overexpression increased it. Mechanistically, GADD45β did not affect Akt-mediated forkhead box protein O1 (FoxO1) phosphorylation and forskolin-induced cAMP response element-binding protein (CREB) phosphorylation. Rather it increased FoxO1 transcriptional activity via enhanced protein stability of FoxO1. Further, GADD45β colocalized and physically interacted with FoxO1. Additionally, GADD45β deficiency potentiated insulin-mediated suppression of hepatic gluconeogenic genes, and it were impeded by the restoration of GADD45β expression. Our finding demonstrates GADD45β as a novel and essential regulator of hepatic gluconeogenesis. It will provide a deeper understanding of the FoxO1-mediated gluconeogenesis.

Disclosure
H. Kim: None.
206-OR: RAGE-Dependent Macrophage Activation Aggravates Retrograde Axonal Transport via Attenuated Insulin Signaling of Peripheral Nerves in Experimental Diabetic Polyneuropathy
Authors: OSONOI SHO , MIZUKAMI HIROKI , KUDO KAZUHIRO , YAMAMOTO YASUHIKO 
Published: June 2021

Advanced glycation end products (AGEs) activates its receptor, RAGE, resulting in a skewing of macrophage (Mϕ) polarity toward inflammatory phenotype (M1) and an impairment of the insulin signaling (IS) in adipose tissue. IS also regulates axonal transport (AT) in the peripheral nervous system. Although impaired IS and AT are assumed to be pathophysiology of diabetic polyneuropathy (DPN), the implication of Mϕ induced inflammation with RAGE activation in those factors is not fully understood. To this end, we generated bone marrow specific RAGE deficient mice to investigate the influence of RAGE signaling in Mϕ on the development of DPN. Bone marrow cells from C57BL/6 mice (W) or RAGE deficient mice (R) were transplanted into irradiated W (BMW and BMR). After 8 weeks of diabetes (D) induced by streptozotocin, nerve conduction velocities were delayed in BMWD compared to BMW, while those of BMRD were comparable to BMR. An increased infiltration of M1 was observed in the sciatic nerve (SN) in BMWD. Western blotting (WB) showed a lower phosphorylation of AKT in response to insulin in SN of BMWD, which suggested impaired IS, while it was maintained in BMRD. Retrograde AT (RAT) was evaluated with Fluoro-gold (FG) transportation from hindlimb-footpad to the dorsal root ganglion (DRG). Immunofluorescence revealed a lower positivity of FG in DRG of BMWD which suggested a deficit of RAT, while it was maintained in BMRD. Neuronal cells isolated from mice DRG were cocultured with a Mϕ cell line RAW264, which was polarized into M1 by AGEs. Intra-axonal vesicles were labeled fluorescently. Subsequently, AT was visualized by time-lapse imaging. The ratio and the velocity of RAT was decreased in the axon of the neurons cocultured with M1 compared with naïve Mϕ.
In summary, our data suggested that the activation of RAGE signaling skewed Mϕ polarity toward M1, impairing IS and RAT through inflammation, which might trigger and develop DPN.

Disclosure
S. Osonoi: None. H. Mizukami: None. K. Kudo: None. Y. Yamamoto: None.

Funding
Japan Society for the Promotion of Science (18K16220)
207-OR: Cardiac Autonomic Neuropathy (CAN) and HDL Proteomics in Type 1 Diabetes (T1D)
Authors: TOYOSHIMA MARCOS T. , SILVA AMANDA , SANTANA MONIQUE DE FATIMA M. , RONSEIN GRAZIELLA E. , CORREA-GIANNELLA MARIA LUCIA , PASSARELLI MARISA 
Published: June 2021

CAN is a common complication of diabetes mellitus (DM) strongly related to cardiovascular (CV) disease, contributing to high morbidity and mortality. HDL is inversely related to CV disease due to its ability in removing excess cholesterol from cells and antioxidant, anti-inflammatory and vasodilation actions. Apart from plasma HDL cholesterol (HDLc) and apoA-I levels that are not invariably changed in T1D, HDL proteomics may contribute to understand HDL functionality and its association with CAN. A total of 50 individuals with T1D with or without CAN were selected to assess the proteome of HDL subfractions (HDL2 and HDL3). CAN evaluation was performed by Ewing test using the Poly-Spectrum software. HDL subfractions were isolated by ultracentrifugation and proteomics analyzed by parallel reaction monitoring (PRM). Subjects with T1D with (n = 15) and without CAN (n = 35) did not differ in age, sex, body mass index, age at DM diagnosis, duration of DM, and fructosamine, HbA1c, total cholesterol, HDLc and triglycerides values. A total of 45 proteins were found in association with HDL2 and HDL3; three proteins were highlighted because they were more abundant in HDL2 from T1D with CAN: α1-microglobulin/bikunin precursor (AMBP), α1-acid glycoprotein (Orm1) and transthyretin (TTR) (Mann-Whitney test; P values &lt;0.01, 0.03, 0.04, respectively). Orm1 is an acute inflammatory phase protein that regulates sphingolipid homeostasis related to the pathogenesis of diabetic neuropathy. TTR carries thyroid hormones and retinol binding protein and mutations in the TTR gene causes amyloidosis that includes motor and sensory polyneuropathy, neuropathic pain and autonomic dysfunction. The AMBP gene encodes α1microglobulin and bicunin that relates to T1D complications.
In conclusion, three proteins with potential for involvement in the pathophysiology of CAN were more abundant in HDL2 in T1D presenting this chronic complication.

Disclosure
M. T. Toyoshima: None. A. Silva: None. M. M. Santana: None. G. E. Ronsein: None. M. Correa-giannella: None. M. Passarelli: None.

Funding
FAPESPCNPq
23-LB: Economic Outcomes and Health Care Utilization of DSMES Interventions: A Systematic Review and Recommendations for Research
Authors: WHITEHOUSE CHRISTINA , SRIVASTAVA SNEHA B. , TUITAMA ADONICA I. KAUWE , BLANCHETTE JULIA E. , HAYDON-GREATTING STARLIN A. , BRADY VERONICA J. , SMITH TIERRA , LITCHMAN MICHELLE L. , YEHL KIRSTEN E. , BZOWYCKYJ ANDREW 
Published: June 2021

Value-driven outcomes are important, especially when health systems are determining sustainability of Diabetes Self-Management Education & Support (DSMES). We conducted a systematic review to synthesize existing research of the economic outcomes and healthcare utilization for interventions that incorporate DSMES in the US. Seven databases were searched for relevant published studies that included of at least one component of the Association of Diabetes Care and Education Specialists 7 Self-Care Behaviors (ADCES7). Reviewers independently selected articles, extracted data and assessed the methodological quality of included studies. In total, 14,804 records were identified, 25 articles met the inclusion criteria. Three articles were determined to have poor quality and were not included in the final analysis. Our findings are based on a total of 22 articles describing 21 studies. DSMES interventions varied widely, including face-to-face education, group classes, home visits with community health workers, telemedicine visits, education modules, and/or visits with registered dietitians, nurses and/or pharmacists. A majority of the studies were not specifically designed for health economic evaluation. Seven studies reported a statistically significant decrease in either total health care costs, hospital or emergency utilization, outpatient medical costs, and/or medication costs. Four of the seven studies utilized all components of the ADCES7. Clinical impact across studies varied. Studies that measured HbA1c found a decrease over their study time frame. The methodological heterogeneity among studies was considerable; therefore, a meta-analysis was not conducted. Our review highlights DSMES interventions may positively impact economic outcomes and/or healthcare utilization, though not all studies showed consistent benefit. This review highlights an evidence gap and future full health economic evaluations are warranted.

Disclosure
C. Whitehouse: None. A. Bzowyckyj: None. S. B. Srivastava: None. A. I. Kauwe tuitama: None. J. E. Blanchette: Board Member; Self; JDRF, Consultant; Self; Insulet Corporation, Other Relationship; Self; Insulet Corporation, Tandem Diabetes Care, Research Support; Self; Association of Diabetes Care and Education Specialists. S. A. Haydon-greatting: None. V. J. Brady: None. T. Smith: None. M. L. Litchman: Research Support; Self; Abbott Diabetes. K. E. Yehl: None.
232-OR: Replacing Sedentary Time by Different Types of Physical Activity and the Risk of Type 2 Diabetes
Authors: LI XIANG , ZHOU TAO , MA HAO , HEIANZA YORIKO , QI LU 
Published: June 2021

Background: Sedentary behaviors have been associated with an increased risk of type 2 diabetes (T2D). The newly released Physical Activity Guidelines for Americans also recommend replacing sedentary behaviors by physical activity. However, it is largely unknown which types of physical activity would be the healthy alternatives to sedentary behaviors, and to what extent it may reduce the risk of T2D.
Methods: We prospectively analyzed the association between sedentary time and risk of T2D among 475,502 participants free of T2D in the UK Biobank. Sedentary time was quantified by summing up the time spent on television watching, computer using, and driving.
Results: During a median follow-up of 11 years, we documented 18,169 incident T2D. Sedentary time were significantly associated with an increased risk of T2D (≥6 hours/day vs. &lt;2 hours/day: hazard ratio [HR]: 1.58; 95% confidence interval (CI): 1.47~1.71). Such associations were more profound among women or obese participants (p-interaction&lt;0.001 for both). Replacing 30 minutes/day sedentary time with different types of physical activities were significantly associated with a 6-31% lower risk of T2D, with strenuous sports (exercise making sweat or breathing hard) showing the strongest risk reduction (per 30 minutes/day: HR: 0.69; 95% CI: 0.63~0.76). Replacing sedentary time by structured exercise showed greater reduction (26%, 23-28%) of T2D risk than by daily-life activity (9%, 8-10%).
Conclusions: Our study indicates that sedentary time combining watching TV, using computer and driving are independently associated with an increased risk of T2D; and replacing sedentary time with the structured exercise is related to greater reduction than with daily activity on T2D risk.

Disclosure
X. Li: None. T. Zhou: None. H. Ma: None. Y. Heianza: None. L. Qi: None.
235-OR: Dorzagliatin as a Glucose Sensitizer Achieved Sustained Glycemic Control with Good Safety Profiles in Drug-Naïve T2D Patients in a 52-Week Phase 3 Monotherapy Trial (SEED)
Authors: CHEN LI , ZHANG YI , ZHU DALONG 
Published: June 2021

Improvement of glucose and insulin sensitivity in T2D remains as an unfulfilled task for the treatment of underlying cause of disease. Dorzagliatin is a first-in-class antidiabetic drug that acts as a glucose sensitizer, which repairs the sensor function of glucokinase(GK) and improves glucose sensitivity. The study aimed to confirm the efficacy and safety of dorzagliatin as a monotherapy in T2D patients. In this randomized, double-blind, placebo-controlled trial, 463 eligible drug-naïve Chinese patients were randomized to 75 mg dorzagliatin or placebo (2:1) twice daily (BID) groups for 24 weeks, followed by the dorzagliatin treatment (75 mg BID) for 28 weeks in both groups. The primary endpoint was the change in the HbA1c from baseline to week 24. The mixed models for repeated measures results suggested that the least squares mean change in HbA1c from baseline at week 24 was -1.07% in the dorzagliatin group, significantly lower than the placebo (P&lt;0.0001), with effects sustained till the end of the 52-week treatment. Significantly improved β-cell function was seen at week 24 in the dorzagliatin group measured by the change in homeostasis model assessment 2-β (HOMA2-β) from baseline compared with the placebo group (2.56 vs. -0.72, P&lt;0.05). The homeostatic control rate (HbA1c &lt;7% without hypoglycemia) at week 24, was 42.2% in the dorzagliatin group compared to 17.3% in the placebo group (P&lt;0.0001). No deaths, drug-related serious adverse events, and severe hypoglycemia were reported. Incidence of the clinically significant hypoglycemia (blood glucose &lt;3.0 mmol/L) was low (&lt;1%). Dorzagliatin had a favorable effect on sustained glycemic control and a good safety profile over 52 weeks in Chinese T2D patients. It is the first successful phase 3 trial for a GK activator. As a glucose sensitizer, dorzagliatin targets the restoration of glucose homeostasis, providing new hope for treating T2D patients.

Disclosure
L. Chen: None. Y. Zhang: Employee; Self; Hua Medicine. D. Zhu: None.
242-OR: Single Nuclei Skeletal Muscle Chromatin and Gene Expression Profiling across 287 Individuals Reveals Cell Type-Specific Genetic Regulatory Architectures at T2D GWAS Loci
Authors: PARKER STEPHEN , VARSHNEY ARUSHI , STUDY FUSION TISSUE ,   GROUP AMP-T2D SKELETAL MUSCLE WORKING
Published: June 2021

Skeletal muscle is the largest organ, by weight (&gt;40%), in the human body; insulin resistance in this and other peripheral tissues is a hallmark of type 2 diabetes (T2D). Recent genome wide association study (GWAS) results show enrichment for T2D and fasting insulin SNPs in skeletal muscle regulatory regions. Identifying gene regulatory mechanisms underlying these associations requires pinpointing the set of causal variants, the target genes these variants regulate, and the specific skeletal muscle cell populations in which they function. Here, we generated single nuclei chromatin (snATAC) and transcription (snRNA) profiles across 287 frozen human skeletal muscle biopsies. We integrated 414,982 nuclei across the modalities with LIGER and identified 13 cell types, ranging in abundance from 38.1% (type 1 fiber) to &lt;1% (adipocyte) of all nuclei. We further integrated genotypes and performed expression and chromatin accessibility quantitative trait loci (e/caQTL) scans in the five most abundant cell types (type 1, type 2a, type 2x, mesenchymal stem cell, endothelial). We identified &gt;70k associations (5% FDR) ranging from shared to cell type-specific and performed colocalization with T2D GWAS signals. Of 73 T2D GWAS signals that colocalize with caQTL, 39 (53.4%) are cell type-specific, highlighting the importance of sn-caQTL maps for GWAS functional studies. For example, in mesenchymal stem cells, we identified a cell type-specific caQTL for an ARL15 intronic peak (rs702634, p=6.6x10-10), which colocalizes with the T2D GWAS signal (coloc H4 posterior probability = 0.95). To nominate target genes for this caQTL peak, we scanned peaks in promoters of genes in the 1 Mb neighborhood and computed co-accessibility scores using Cicero in an allele-specific manner, which identified the gene FST, ~493 kb away. FST encodes for follistatin which increases muscle growth and reduces fat mass and insulin resistance.

Disclosure
S. Parker: None. A. Varshney: None. Fusion tissue study: n/a. Amp-t2d skeletal muscle working group: n/a.

Funding
American Diabetes Association/Pathway to Stop Diabetes (1-14-INI-07 to S.P.); National Institutes of Health (R01DK117960, U01DK06237017, UM1DK126185)
246-OR: Probing the Role of Alternative Splicing of IKZF1 in Risk for Type 1 Diabetes
Authors: PALOMO LUCIA PASTOR , NEWMAN JEREMY R.B. , ATKINSON MARK A. , CONCANNON PATRICK J. 
Published: June 2021

Genome wide association studies have identified a region at chromosome 7p12.2, containing the IKZF1 gene, that is associated with type 1 diabetes (T1D). IKZF1 encodes Ikaros, a transcription factor and critical regulator of lymphocyte development and homeostasis. The IKZF1 gene includes 9 exons that produce at least 10 distinct transcripts. Exons 3-5 encode 4 zinc finger motifs that mediate DNA binding, while the last exon encodes 2 zinc fingers that allow homo- or heterodimerization. We examined the expression of IKZF1 using RNA-seq data from different lymphocyte populations. Individual coding exons of IKZF1, notably exons 3 and 5, displayed significant differences in usage between CD4+ T cells, CD8+ T cells and CD19+ B cells among T1D cases as well as between cases and controls in memory CD4+ T cells. This suggested that specific transcript isoforms of IKZF1 are differentially expressed in lymphocyte subtypes as well as in T1D. To explore the role of alternative splicing of IKZF1 in T1D, CRISPR/cas9 was used to generate Jurkat T cell lines with truncating mutations in either IKZF1 exon 3, exon 5 or both. Clones were isolated by serial dilution and characterized by PCR amplification and DNA sequencing. Twenty clones with different IKZF1 mutations were identified. Immunoblots revealed shifts in Ikaros protein isoform abundance consistent with the exon targeting in individual clones. Mutation of exons 3 or 5 resulted in the upregulation of 218 genes and the downregulation of 309 genes, as assayed by RNA-seq. Interrogation of ENCODE project data showed that most of these differentially expressed genes have an IKZF1 ChIP-seq peak within 1kb of the gene, consistent with their being targets of Ikaros regulation. These results suggest that the number of zinc finger domains in Ikaros, rather than their sequence or structure, modulates their impact. More broadly, the differential expression of IKZF1 transcripts distinguishes the transcriptomes of specific lymphocyte populations in both T1D cases and controls.

Disclosure
L. Pastor palomo: Employee; Spouse/Partner; Cox Business. J. R. B. Newman: None. M. A. Atkinson: None. P. J. Concannon: Stock/Shareholder; Self; Amgen Inc.

Funding
National Institutes of Health (R01DK116954, P01AI042288)
247-OR: Variant-to-Gene-Mapping Analyses Reveal a Role for Pancreatic Islet Cells in Conferring Genetic Susceptibility to Sleep-Related Traits
Authors: LASCONI CHIARA , PAHL MATTHEW C. , PIPPIN JAMES A. , SU CHUN , JOHNSON MATTHEW , CHESI ALESSANDRA , WELLS ANDREW D. , KAESTNER KLAUS H. , GRANT STRUAN F.A. 
Published: June 2021

Altered glucose metabolism observed in sleep dysregulation has been reported to contribute to obesity and type 2 diabetes (T2D) risk. We elected to investigate if known sleep loci exert any of their effect in the pancreatic alpha and beta-cell setting. To establish genetic commonalities between sleep and metabolic disorders, we conducted linkage disequilibrium (LD) genetic correlation analyses with publicly available GWAS summary statistics for 4 sleep-associated traits (insomnia, chronotype, short and long sleep), T2D and obesity. Insomnia was significantly correlated with both T2D (genetic correlation (rg)=0.2; P=2.4x10-11) and obesity (rg=0.13; P=0.0021), as was short sleep (T2D, rg=0.2; P=1.8x10-10; obesity, rg=0.22; and P=5.1x10-7) and long sleep (T2D, rg=0.23; P=3.1x10-10; obesity rg=0.09; P=0.019). Chronotype was significantly correlated with T2D only (rg=0.05; P=0.038). Using partitioned LD score regression we then intersected summary statistics with our ATAC-seq and high-resolution promoter-focused Capture C data to assess enrichment of sleep trait SNPs within promoter-interacting open chromatin regions in both the human beta-cell line, EndoC-BH1, and sorted human alpha-cells. EndoC-BH1 was highly significantly enriched for chronotype loci (P=2.2x10-7). Furthermore there was significant enrichment for insomnia (P=0.01) and short sleep (P=0.017). The alpha-cells were also significantly enriched for chronotype (P=0.0016), insomnia (P=0.0076), short sleep (P=0.022), along with long sleep (P=0.034). Motivated by these observations, subsequent variant-to-gene mapping implicated 32, 37 and 6 putative effector genes for insomnia, chronotype and short sleep, respectively, in EndoC-BH1. For alpha-cells, 55, 54, 10 and 5 genes were implicated for insomnia, chronotype, short and long sleep, respectively. Our data suggest that a subset of sleep-related loci confer their effects via cells in pancreatic islets.

Disclosure
C. Lasconi: None. M. C. Pahl: None. J. A. Pippin: None. C. Su: None. M. Johnson: None. A. Chesi: None. A. D. Wells: None. K. H. Kaestner: None. S. F. A. Grant: None.

Funding
National Institutes of Health (UM1DK126194)