Mouse Model Of Type 1 Diabetes Research Articles

Cluster of Differentiation 4 T Cells and Neoantigens in Autoimmune Diabetes

Our investigations of antigens for pathogenic T cells in autoimmune diabetes led to the discovery of hybrid insulin peptides as T cell epitopes. T cells reactive to hybrid insulin peptides can be found at high frequency in the nonobese diabetic mouse model of type 1 diabetes and are also present in human patients. Hybrid insulin peptides can also be administered to mice in a tolerogenic form, thereby suppressing the autoimmune response.

MAIT Cells in Type 1 Diabetes Mouse Models.

MAIT cells are unconventional T cells expressing a semi-invariant αβ TCR, and they recognize bacterial metabolites via the highly conserved MR1 protein. MAIT cells interact with gut microbiota and literature reports alterations of gut homeostasis in type 1 diabetes (T1D), suggesting the involvement of MAIT cells in T1D. Since NOD mice is a well-established mouse model of T1D, MAIT cells were studied in these mice to evaluate their potential involvement in disease development. This chapter describes the material and methods required to characterize MAIT cells and to determine their function in T1D mouse models.

Monitoring type 2 diabetes from volatile faecal metabolome in Cushing\u2019s syndrome and single Afmid mouse models via a longitudinal study

The analysis of volatile organic compounds (VOCs) as a non-invasive method for disease monitoring, such as type 2 diabetes (T2D) has shown potential over the years although not yet set in clinical practice. Longitudinal studies to date are limited and the understanding of the underlying VOC emission over the age is poorly understood. This study investigated longitudinal changes in VOCs present in faecal headspace in two mouse models of T2D – Cushing’s syndrome and single Afmid knockout mice. Longitudinal changes in bodyweight, blood glucose levels and plasma insulin concentration were also reported. Faecal headspace analysis was carried out using selected ion flow tube mass spectrometry (SIFT-MS) and thermal desorption coupled to gas chromatography-mass spectrometry (TD-GC-MS). Multivariate data analysis of the VOC profile showed differences mainly in acetic acid and butyric acid able to discriminate the groups Afmid and Cushing’s mice. Moreover, multivariate data analysis revealed statistically significant differences in VOCs between Cushing’s mice/wild-type (WT) littermates, mainly short-chain fatty acids (SCFAs), ketones, and alcohols, and longitudinal differences mainly attributed to methanol, ethanol and acetone. Afmid mice did not present statistically significant differences in their volatile faecal metabolome when compared to their respective WT littermates. The findings suggested that mice developed a diabetic phenotype and that the altered VOC profile may imply a related change in gut microbiota, particularly in Cushing’s mice. Furthermore, this study provided major evidence of age-related changes on the volatile profile of diabetic mice.

Metabolically Active Brown Adipose Tissue Is Found in Adult Subjects with Type 1 Diabetes.

Type 1 diabetes (T1D) is characterized by the loss of insulin-producing cells and hence insulin secretion and metabolic control. In addition to insulin, there are a number of hormones and cytokines that influence metabolism, and many of these can be secreted from brown adipose tissue (BAT). However, the presence and activity of BAT in T1D have not been studied, despite the fact that preclinical studies have shown that transplantation of BAT in mouse models of T1D can restore metabolic control. The metabolic activity of BAT, white adipose tissue (WAT), and skeletal muscle was investigated in patients with T1D (n = 11) by 2-deoxy-2-(18F)fluoro-D-glucose PET/CT after cold stimulation. Functional BAT was detected in 4 out of 11 individuals with T1D with a prevalence of 36%. The glucose utilization rate in the supraclavicular BAT regions ranged from 0.75–38.7 µmol × min−1 × 100 g−1. The glucose utilization per gram tissue was higher in BAT when compared with both WAT (p = 0.049) and skeletal muscle (p = 0.039). However, no correlation between BAT activity and metabolic control or insulin requirements was found. In conclusion, for the first time, cold-induced BAT was detected in patients with T1D with a wide range in metabolic activity. Contrary to findings in animal models, the metabolic activity of BAT had negligible impact on insulin requirements or metabolic control in T1D under normal physiological conditions.

MiR-495 regulates macrophage M1/M2 polarization and insulin resistance in high-fat diet-fed mice via targeting FTO.

MicroRNA 495 (miR-495) has been discovered to be involved in the metabolism and immune response in human body. The purpose of this study was to investigate the effect of miR-495 on macrophage M1/M2 polarization and insulin resistance in type 2 diabetes (T2D). A T2D mouse model was established by feeding C57BL/6 mice with a high-fat diet (HFD). The expressions of M1/M2 polarization markers and miR-495 in peritoneal macrophages were determined by qRT-PCR or Western blot. Mouse insulin tolerance test (ITT) and glucose tolerance test (GTT) were performed, and the targeted binding effect between miR-495, fat mass, and obesity-associated gene (FTO) was verified by double luciferase gene reporter assay. The body weight, blood glucose content, and miR-495 expression in macrophages of the HFD group were remarkably higher than those of the normal diet (ND) group. Besides, miR-495 induced the transformation of macrophages into M1-type pro-inflammatory macrophages and enhanced the insulin resistance of T2D mice. More importantly, FTO was proved to be a direct target gene of miR-495 and silencing FTO could induce the transformation of macrophages into M1-type pro-inflammatory macrophages. These results demonstrated that miR-495 could promote the transformation of macrophages into M1-type pro-inflammatory macrophages by inhibiting the expression of its target gene FTO, and aggravate the insulin resistance and adipose tissue inflammation in T2D mice, which provided a certain theoretical basis for the targeted treatment of T2D.

Prolonged half-life of small-sized therapeutic protein using serum albumin-specific protein binder

Many small-sized proteins and peptides, such as cytokines and hormones, are clinically used for the treatment of a variety of diseases. However, their short half-life in blood owing to fast renal clearance usually results in a low therapeutic efficacy and frequent dosing. Here we present the development of a human serum albumin (HSA)-specific protein binder with a binding affinity of 4.3nM through a phage display selection and modular evolution approach to extend the blood half-life of a small-sized therapeutic protein. As a proof-of-concept, the protein binder composed of LRR (Leucine-rich repeat) modules was genetically fused to the N-terminus of Glucagon-like Peptide-1 (GLP-1). The fused GLP-1 was shown to have a significantly improved pharmacokinetic property: The terminal half-life of the fused GLP-1 increased to approximately 10h, and the area under the curve was 5-times higher than that of the control. The utility and potential of our approach was demonstrated by the efficient control of the blood glucose level in type-2 diabetes mouse models using the HSA-specific protein binder-fused GLP-1 over a prolonged time period. The present approach can be effectively used in enhancing the efficacy of small-sized therapeutic proteins and peptides through an enhanced blood circulation time.

Type 2 Diabetes-Driven Alterations in Bone Healing and Angiogenesis

Background and Hypothesis: Type 2 diabetes (T2D) is prevalent in the United States. T2D patients are at risk for impaired fracture healing due to decreased angiogenesis, which is required for successful bone regeneration. Bone morphogenetic protein-2 (BMP-2) is often used to help orthopedic surgeons with bone healing in difficult cases. Here, we begin characterizing the mechanism by which T2D alters bone healing with or without BMP-2 treatment. We hypothesize that T2D impairs fracture healing by decreasing angiogenesis and endothelial cell function.
 Project Methods: Using Tie2-CreER;Td-Tomato mice (Tie2CreERT+), we established a high fat diet (HFD)-induced T2D mouse model to compare with control low fat diet (LFD)-fed mice. Mice underwent testing to confirm the T2D-like metabolic phenotype, underwent a femoral critical-size defect surgery that was treated with either saline or BMP-2, and were then assessed biweekly by X-ray imaging over the course of 12 weeks. Finally, bone marrow-derived endothelial cells were collected from these mice to assess changes in endothelial colony and tube formation in vitro.
 Results: Results showed that the HFD mice acquired the T2D metabolic phenotype. Fracture healing was impaired in the HFD mice, even with BMP-2 treatment. The isolation of BMECs was confirmed by visualization of fluorescent Tie2+ cells. Unexpectedly, in vitro tube formation assays indicated that HFD improved vessel-like formation properties. BMP-2 treatment appeared to improve some vessel-like formation properties compared to control treatment.
 Conclusion and Potential Impact: This study is ongoing. Further data will need to be collected to better characterize differences in bone healing and angiogenesis in the healing femurs. Still, these data reveal the mechanisms by which T2D impairs bone healing and demonstrate the important difference between examining endothelial cells in vitro vs. in vivo. Future investigations will examine if thrombopoietin, which our group has previously shown to improve both fracture healing and angiogenesis, may be a more effective treatment than BMP-2 in this model.

Urinary angiotensinogen increases in the absence of overt renal injury in high fat diet-induced type 2 diabetic mice

Aim of the StudyDuring type 2 diabetes (T2D) and hypertension there is stimulation of renal proximal tubule angiotensinogen (AGT), but whether urinary excretion of AGT (uAGT) is an indicator of glomerular damage or intrarenal RAS activation is unclear. We tested the hypothesis that elevations in uAGT can be detected in the absence of albuminuria in a mouse model of T2D. MethodsMale C57BL/6 mice (N = 10) were fed a high fat (HFD; 45% Kcal from fat) for 28 weeks, and the metabolic phenotype including body weight, blood pressures, glucose, insulin, ippGTT, HOMA-IR, and cholesterol was examined. In addition, kidney Ang II content and reactive oxygen species (ROS) was measured along with urinary albumin, creatinine, Ang II, and AGT. ResultsAll parameters consistent with T2D were present in mice after 12–14 weeks on the HFD. Systolic BP increased after 18 weeks in HFD but not NFD mice. Intrarenal ROS and Ang II concentrations were also increased in HFD mice. Remarkably, these changes paralleled the augmentation uAGT excretion (3.66 ± 0.50 vs. 0.92 ± 0.13 ng/mg by week 29; P < 0.01), which occurred in the absence of overt albuminuria. ConclusionsIn HFD-induced T2D mice, increases in uAGT occur in the absence of overt renal injury, indicating that this biomarker accurately detects early intrarenal RAS activation.

Kinetics of immune cell responses in the multiple low-dose streptozotocin mouse model of type 1 diabetes.

In type 1 diabetes (T1D), the insulin‐producing β cells are destructed by immune mechanisms. It has been hypothesized that the very first immune response in T1D onset comes from innate immune cells, which further activates the adaptive immune cells to attack the islets. Despite intensive research on characterization of islet‐infiltrating immune cells, the kinetics of different immune cells in multiple low‐dose streptozotocin (MLDSTZ)‐induced T1D mouse model is still much unclear. Therefore, we investigated the proportions of innate immune cells such as neutrophils, dendritic cells (DCs), plasmacytoid dendritic cells (pDCs), macrophages, natural killer (NK) cells, and adaptive immune cells (T and B lymphocytes) in thymi, pancreatic‐draining lymph nodes, and spleens of MLDSTZ mice on days 3, 7, 10, and 21 after the first injection of STZ by flow cytometry. The proportions of DCs and B cells were increased from day 3, while the proportions of B‐1a lymphocytes and interferon‐γ+ cells among NK cells were increased, but NK cells were decreased on day 10 in MLDSTZ‐treated mice, illustrating that the initial immune response is induced by DCs and B cells. Later, the proportions of T helper 1 and cytotoxic T cells were increased from day 7, suggesting that the innate immune cells precede adaptive immune cell response in MLDSTZ mice. Altogether, our data demonstrate a possible sequence of events regarding the involvement of DCs, pDCs, NK cells, B‐1a lymphocytes, B, and T cells at the early stage of T1D development.

The type 1 diabetes candidate gene Dexi does not affect disease risk in the nonobese diabetic mouse model.

Genome wide association studies have implicated more than 50 genomic regions in type 1 diabetes (T1D). A T1D region at chromosome 16p13.13 includes the candidate genes CLEC16A and DEXI. Conclusive evidence as to which gene is causal for the disease-association of this region is missing. We previously reported that Clec16a deficiency modified immune reactivity and protected against autoimmunity in the nonobese diabetic (NOD) mouse model for T1D. However, the diabetes-associated SNPs at 16p13.13 were described to also impact on DEXI expression and others have argued that DEXI is the causal gene in this disease locus. To help resolve whether DEXI affects disease, we generated Dexi knockout (KO) NOD mice. We found that Dexi deficiency had no effect on the frequency of diabetes. To test for possible interactions between Dexi and Clec16a, we intercrossed Dexi KO and Clec16a knockdown (KD) NOD mice. Dexi KO did not modify the disease protection afforded by Clec16a KD. We conclude that Dexi plays no role in autoimmune diabetes in the NOD model. Our data provide strongly suggestive evidence that CLEC16A, not DEXI, is causal for the T1D association of variants in the 16p13.13 region.

Decitabine assists umbilical cord-derived mesenchymal stem cells in improving glucose homeostasis by modulating macrophage polarization in type 2 diabetic mice

BackgroundMesenchymal stem cells (MSCs) have emerged as a promising therapy for type 2 diabetes (T2D). Mechanistic researches demonstrate that the anti-diabetic effect of MSCs is partially mediated by eliciting macrophages into an anti-inflammatory phenotype thus alleviating insulin resistance. However, single MSC infusion is insufficient to ameliorate sustained hyperglycemia or normalize blood glucose levels. In this study, we used decitabine (DAC), which is involved in the regulation of macrophage polarization, to test whether MSCs combined with decitabine can prolong and enhance the anti-diabetic effect in T2D mice.MethodsHigh-fat diet (HFD) and streptozocin (STZ) were given to induce T2D mouse model. Successfully induced T2D mice were randomly divided into four groups: T2D group, MSC group, DAC group, and MSC + DAC group. Blood glucose was monitored, and glucose tolerance and insulin sensitivity were evaluated during the entire analysis period. Epididymal fat was extracted for analysis of macrophage phenotype and inflammation in adipose tissue. In vitro, we examined the effect of MSC + DAC on macrophage polarization in bone marrow-derived macrophages (BMDMs) and explore the possible mechanism.ResultsMSC infusion effectively improved insulin sensitivity and glucose homeostasis in T2D mice within 1 week, whereas combination therapy of MSCs + DAC extended the anti-diabetic effects of MSCs from 1 to 4 weeks (the end of the observation). Correspondingly, more M2 macrophages in adipose tissue were observed in the combination therapy group over the entire study period. In vitro, compared with the MSC group, MSCs combined with decitabine more effectively polarized M1 macrophages to M2 macrophages. Further analysis showed that the effect of MSC + DAC on macrophage polarization was largely abrogated by the peroxisome proliferator-activated receptor gamma (PPARγ) antagonist GW9662.ConclusionsOur data suggest that MSCs combined with decitabine can more effectively alleviate insulin resistance and prolong and enhance the anti-diabetic effect of MSCs in T2D mice in part by prompting M2 polarization in a PPARγ-dependent manner. Thus, decitabine may be an applicable addition to MSCs for diabetes therapy.Graphic UC-MSCs combined with decitabine activate the IL4R/STAT6/STAT3/PPARγ axis to further promote M2 macrophage polarization in adipose tissue, reduce inflammation, improve insulin sensitivity, and lead to better glucose metabolism and long-term hypoglycemic effects

Synthetically glycosylated antigens induce antigen-specific tolerance and prevent the onset of diabetes.

Homeostatic antigen presentation by hepatic antigen-presenting cells, which results in tolerogenic T-cell education, could be exploited to induce antigen-specific immunological tolerance. Here we show that antigens modified with polymeric forms of either N-acetylgalactosamine or N-acetylglucosamine target hepatic antigen-presenting cells, increase their antigen presentation and induce antigen-specific tolerance, as indicated by CD4+ and CD8+ T-cell deletion and anergy. These synthetically glycosylated antigens also expanded functional regulatory T cells, which are necessary for the durable suppression of antigen-specific immune responses. In an adoptive-transfer mouse model of type-1 diabetes, treatment with the glycosylated autoantigens prevented T-cell-mediated diabetes, expanded antigen-specific regulatory T cells and resulted in lasting tolerance to a subsequent challenge with activated diabetogenic T cells. Glycosylated autoantigens targeted to hepatic antigen-presenting cells might enable therapies that promote immune tolerance in patients with autoimmune diseases.

Antigen-specific immune tolerance in the liver.

Targeting antigens to the liver by glycosylation promotes antigen-specific immune tolerance via the expansion of regulatory T cells and prevents autoimmunity in a mouse model of type-1 diabetes.

Preactivation of β-catenin in osteoblasts improves the osteoanabolic effect of PTH in type 1 diabetic mice.

Type 1 diabetes (T1D) is correlated with osteopenia primarily due to low bone formation. Parathyroid hormone (PTH) is a known anabolic agent for bone, the anabolic effects of which are partially mediated through the Wnt/β-catenin signaling pathway. In the present study, we first determined the utility of intermittent PTH treatment in a streptozotocin-induced T1D mouse model. It was shown that the PTH-induced anabolic effects on bone mass and bone formation were attenuated in T1D mice compared with nondiabetic mice. Further, PTH treatment failed to activate β-catenin signaling in osteoblasts of T1D mice and was unable to improve osteoblast proliferation and differentiation. Next, the Col1-3.2 kb-CreERTM; β-cateninfx(ex3) mice were used to conditionally activate β-catenin in osteoblasts by injecting tamoxifen, and we addressed whether or not preactivation of β-catenin boosted the anabolic action of PTH on T1D-related bone loss. The results demonstrated that pretreatment with activation of osteoblastic β-catenin followed by PTH treatment outperformed PTH or β-catenin activation monotherapy and led to greatly improved bone structure, bone mass, and bone strength in this preclinical model of T1DM. Further analysis demonstrated that osteoblast proliferation and differentiation, as well as osteoprogenitors in the marrow, were all improved in the combination treatment group. These findings indicated a clear advantage of developing β-catenin as a target to improve the efficacy of PTH in the treatment of T1D-related osteopenia.

Leukotriene-B4 modulates macrophage metabolism and fat loss in type 1 diabetic mice.

Serum levels of leukotriene-B4 (LTB4) are increased in type 1 diabetes (T1D) and it mediates systemic inflammation and macrophage reprogramming associated with this condition. Herein, we investigated the involvement of LTB4 in adiposity loss, hyperlipidemia, and changes in macrophage metabolism in a mouse model of streptozotocin-induced T1D. LTB4 receptor (BLT1) antagonist u75302 was employed to block LTB4 effects. As expected, hypoinsulinemia in T1D was associated with hyperglycemia, low levels of glucagon, hyperlipidemia, significant body fat loss, and increased white adipose tissue expression of Fgf21, a marker for lipolysis. With the exception of hyperglycemia and hypoglucagonemia, blockade of LTB4 signaling reverted these parameters in T1D mice. Along with hyperlipidemia, macrophages from T1D mice exhibited higher lipid uptake and accumulation. These cells also had enhanced glycolysis and oxidative metabolism and these parameters were dependent on the mitochondrial uncoupling respiration, as evidenced by elevated expression of oxidation markers carnitine palmitoyltransferase and uncoupling protein 1. Interestingly, all these parameters were at least partially reverted in T1D mice treated with u75302. Altogether, these findings suggest that in T1D mice LTB4/BLT1 is involved in the fat loss, hyperlipidemia, and increased macrophage lipid uptake and metabolism with an important involvement of mitochondrial uncoupling activity. These previously unrecognized LTB4/BLT1 functions may be explored in future to therapeutically alleviate severity of hyperlipidemia and systemic inflammation in T1D.

High-Fat Diet Alters the Intestinal Microbiota in Streptozotocin-Induced Type 2 Diabetic Mice.

Intestinal microbiota is closely associated with various metabolic diseases such as type 2 diabetes (T2D), and microbiota is definitely affected by diet. However, more work is required to gain detailed information about gut metagenome and their associated impact with diet in T2D patients. We used a streptozotocin-high-fat diet (HFD) to induce a T2D mouse model and investigated the effect of standard chow diet and HFD on the composition and function of gut microbiota. We found that a HFD could worsen the diabetes status compared with a standard diet. 16S rRNA gene sequencing revealed that a HFD caused a large disturbance to the microbial structure and was linked to an increased ratio of Firmicutes to Bacteroidetes. A HFD increased the bacteria of the Ruminococcaceae and Erysipelotrichaceae family and decreased the bacteria of S24-7 and Rikenellaceae. Meanwhile, a HFD decreased the abundance of Parabacteroides distasonis and Eubacterium dolichum, both of which have previously been reported to alleviate obesity and metabolic dysfunctions. Moreover, PICRUSt-predicted KEGG pathways related to membrane transport, lipid metabolism, and xenobiotics biodegradation and metabolism were significantly elevated in HFD-fed T2D mice. Our results provide insights into dietary and nutritional approaches for improving host metabolism and ameliorating T2D.

91-OR: Stem Cell-Derived Tissue-Associated Regulatory T Cells Suppress the Activity of Pathogenic Immune Cells in Autoimmune Diabetes

The auto antigen (Ag)-specific regulatory T cells (Tregs) from pluripotent stem cells (PSCs), i.e., PSC-Tregs, have the ability to suppress autoimmunity. PSC-Tregs can be programmed to be tissue-associated and to infiltrate into local inflamed tissues to suppress autoimmune responses after adoptive transfer. Nevertheless, the mechanisms by which the auto Ag-specific PSC-Tregs suppress the autoimmune response remain to be fully elucidated. In this study, we generated the functional auto Ag-specific Tregs from the induced PSC (iPSCs), i.e., iPSC-Tregs, and investigated the underlying mechanisms of autoimmunity suppression by these Tregs in a type 1 diabetes (T1D) murine model. A double transgenic (Tg) mouse model of T1D was established in F1 mice in which the first generation of RIP-mOVA Tg mice that were crossed with OT-I T cell receptor (TCR) Tg mice was challenged with vaccinia viruses expressing OVA (VACV-OVA). We show that adoptive transfer of OVA-specific iPSC-Tregs greatly suppressed autoimmunity in the animal model and prevented the insulin-secreting pancreatic β cells from destruction. Further, we demonstrate that the adoptive transfer significantly reduced the expression of ICAM-1 in the diabetic pancreas and inhibited the migration of pathogenic CD8+ T cells and the production of the pro-inflammatory IFN-γ in the pancreas. These results indicate that the stem cell-derived tissue-associated Tregs can robustly accumulate in the diabetic pancreas, and through down-regulating the expression of ICAM-1 in the local inflamed tissues and inhibiting the production of pro-inflammatory cytokine IFN-γ, suppress the migration and activity of the pathogenic immune cells that cause T1D. Disclosure J.J. Song: None. Funding American Diabetes Association (1-16-IBS-281); National Institutes of Health (R01AI121180, R21AI109239)

1740-P: Gene-Editing of FOXP3 in Antigen-Specific CD4+ T Cells for Restoration of Immune Tolerance in Type 1 Diabetes

Clinical trials for type 1 diabetes (T1D) using expanded, autologous natural regulatory T cells (nTreg) have demonstrated safety and sustained engraftment. Limitations to this approach include the requirement for potential instability in vivo, lack of antigen specificity, and intrinsic Treg defects in some patients. As an alternative strategy, we used gene editing to convert primary human or mouse CD4+T cells into immunosuppressive Treg-like cells. Our approach utilizes co-delivery of designer nucleases and AAV6 homology-directed repair templates to enforce the expression of FOXP3, a transcription factor determining Treg development. These edited (ed)Treg exhibit a phenotype and functional activity similar to nTreg and ameliorate the inflammatory xenograft response of effector T cells in NOD-scid-Il2rgnull (NSG) mice. In the current study, we hypothesized that antigen-specific edTreg would exhibit increased potency in treatment of autoimmune diseases including T1D. As an initial test of feasibility, we generated edTreg from flu- or tetanus-specific human CD4+ T cells and demonstrated antigen-specific suppressive activity. Next, we show proof-of-concept for antigen (Ag)-specific edTreg in a T1D mouse model. Using mouse-specific nucleases and donor templates, we edited CD4+T cells from transgenic NOD mice expressing the diabetogenic, BDC2.5, TCR. BDC2.5 edTreg were similar to nTreg on the basis of key cell markers and cytokine production. BDC2.5 edTreg or polyclonal edTreg from NOD mice were co-transferred with effector BDC2.5 T cells (CD4+CD25-) into NSG mice. Recipients of only effector cells exhibited rapid diabetes onset. In contrast, edTreg delayed disease and, as hypothesized, Ag-specific edTreg exhibited much greater suppression and longer delays in T1D onset. Together, our findings demonstrate the capacity to generate functional, Ag-specific, edTreg with potential therapeutic application in promoting immune tolerance in T1D. Disclosure Y. Xiang: None. K. Sommer: None. Y. Honaker: None. J. Smith: None. T.R. Torgerson: Consultant; Self; CSL Behring, Grifols, Shire, UCB, Inc. Research Support; Self; CSL Behring. J. Buckner: None. D. Rawlings: None. Funding Seattle Children’s Research Institute, Seattle Children's Center for Immunity and Immunotherapies; Seattle Children's Program in Cell and Gene Therapy; Seattle Children's Guild Association (to D.R.); The Leona M. and Harry B. Helmsley Charitable Trust (to D.R.); National Institutes of Health (DP3DK111802-01 to D.R.)

31-LB: Identification of Repurposable Drug Candidate for Diabetic Peripheral Neuropathy Using High-Throughput Drug-Perturbation Data

Diabetic peripheral neuropathy (DPN) is a common complication of prediabetes and type 2 diabetes (T2D) for which there are limited treatment options. We recently demonstrated that dietary reversal (DR) corrects the DPN phenotype using mouse models of prediabetes and T2D. However, it is still important to develop therapeutic agents for treating DPN in addition to life style changes such as DR. In this study, we employed an in silico omics-based systems approach to identify small-molecule drugs with a high potential of reversing or halting DPN. The NIH Library of Integrated Network-based Cellular Signatures (LINCS) drug-perturbation transcriptomic data were obtained, which measured gene expression changes after treatment of 83 human cells with over 20,000 small-molecule compounds using the L1000 assay platform. Gene expression signature of DPN, consisting of highly up- or down-regulated genes, was defined based on the dysregulated genes, identified from sciatic nerves RNA-Seq data of C57BL/6J mice fed with high-fat diet (60% kcal fat for 19 weeks). This DPN signature was compared against the LINCS perturbation data using the CLUE Query app from the Broad Institute and our in-house analysis pipeline. The top small-molecule drugs, demonstrating opposite expression profiles of the DPN signature, included various protein synthesis inhibitors, calcium channel blockers, and adrenergic receptor antagonists such as cephaeline, levetiracetam, and esmolol, respectively. Although the anti-DPN effects of these drugs need to be systematically examined, our systems approach provides a list of drugs with a potential for being used to treat DPN. Disclosure K. Guo: None. E.L. Feldman: None. J. Hur: None. Funding National Institutes of Health (R24DK082841); University of Michigan

359-OR: 12/15-Lipoxygenase in Islets and Macrophages Independently Promotes Autoimmune Diabetes in NOD Mice

The pathogenesis of type 1 diabetes (T1D) involves the interaction of the immune system with β cells. 12/15-lipoxygenase (12/15-LOX), an enzyme involved in arachidonic acid metabolism, is expressed in both β cells and macrophages. Global deletion of the gene encoding 12/15-LOX (Alox15) prevents diabetes in the NOD mouse model of T1D via reduction in production of proinflammatory mediators in islets and macrophages. However, the importance of 12/15-LOX in islets vs. macrophages remains unclear. To address this issue, we generated both inducible islet-cell-specific (NOD-Alox15∆islet) and myeloid-lineage-specific (Alox15∆myel) Alox15 knockout mice on the NOD background. Control female mice (Alox15loxp/loxp, Pdx1PB-CreERTM+, and LysM-Cre+) exhibited diabetes incidence greater than 75%, whereas both Alox15∆islet and Alox15∆myel showed a dramatic decrease in the incidence of diabetes (&amp;lt;10%, P&amp;lt;0.05). During the pre-diabetic phase (8 weeks of age), both control and Alox15∆islet mice exhibited similar β-cell mass (0.70±0.08 g vs. 0.72±0.06 g, P=NS) and insulitis severity (score 1.89±0.17 vs. 1.74±0.19, P=NS), whereas Alox15∆myel mice had increased β-cell mass (1.56±0.02c g, P&amp;lt;0.05) and insulitis (score 1.18±0.08, P&amp;lt;0.05). We next examined the nature of immune cells present in the spleen and pancreatic lymph node (pLN). Alox15∆islet mice showed increased Tregs (CD4+FoxP3; P&amp;lt;0.05) with no changes in Th1 (CD4+IFNγ+) and Th17 (CD4+IL17+) cells in both the spleen and pLN compared to control mice (P=NS). Additionally, Alox15∆islet female mice exhibited decreased IL-1β production by dendritic cells. By contrast, Alox15∆myel mice showed only decreased pLN proinflammatory macrophages (F480+IL1β+) and dendritic cells (CD11c+IL1β+) compared to controls (P&amp;lt;0.05). Together, these data suggest that 12/15-LOX functions independently in both the islet and macrophage through different mechanisms, promoting the destruction of β cells during the pathogenesis of autoimmune T1D. Disclosure A. Pineros Alvarez: None. A. Kulkarni: None. K. Orr: None. L. Glenn: None. C.A. Reissaus: None. M. Hernandez-Perez: None. M. Gannon: None. M.J. McDuffie: Stock/Shareholder; Self; Adenosine Therapeutics, LLC. J. Nadler: None. R. Mirmira: None. M.A. Morris: Stock/Shareholder; Spouse/Partner; Sanofi US. S.A. Tersey: None. Funding National Institutes of Health (R01DK105588 to R.M., J.N.)