bluuebunny/crossref_metadata_2025_split huggingface dataset:
Melatonin Improves Neovascularization after Hind-Limb Ischemia Surgery in Streptozocin-Induced Diabetic Mice by Enhancing Endothelial Progenitor Cells Functions
Authors: KUO CHIN-SUNG , HUANG PO-HSUN , LIN SHING-JONG 
Published: June 2018

Objective: Diabetic patients show poor endothelial progenitor cell (EPC) functions and are prone to ischemic micro-vascular or macro-vascular complications. Melatonin has been shown to have protective effects in ischemic injury, possibly in part by modulating the functioning of EBCs. We investigated whether pretreatment with melatonin can restore the impaired functions of EPCs in diabetes.
Methods: Human EPC were isolated and cultured in a high-glucose medium for functional testing. Cell proliferation, nitric oxide (NO) production, and apoptosis assay were examined. A streptozocin (STZ)-induced diabetic mouse model was established to evaluate the actions of chronic hyperglycemia on ischemia-induced blood flow recovery. The circulating EPC number in the peripheral blood was determined by flow cytometry (Sca-1+/Flk-1+).
Results: Incubation with a high-glucose medium (25 mM) significantly suppressed EPC proliferation, reduced NO production, and lessened phosphorylations of Akt and eNOS. Moreover, EPC treated with high-glucose medium increased reactive oxygen species production, promoted cellular apoptosis and senescence, and also inhibited EPC tube formation. Treatment of melatonin could recover these harmful effects. Four weeks after hindlimb ischemia surgery, the STZ-induced diabetic mice had significantly reduced tissue reperfusion, EPC mobilization, and impaired neovascularization in the ischemic hindlimbs compared with the nondiabetic mice. In STZ-induced diabetic mice, the melatonin group showed significantly increased ischemic/non-ischemic limb blood perfusion ratios, higher capillary densities, and improved EPC mobilization.
Conclusion: Chronic hyperglycemia impaired blood flow recovery and EPC mobilization in response to tissue ischemia, and pretreatment of melatonin could reduce these effects.

Disclosure
C. Kuo: None. P. Huang: None. S. Lin: None.
Dietary Fat Quality and Genetic Risk of Type 2 Diabetes
Authors: MERINO JORDI , DASHTI HASSAN S. , GUASCH MARTA , ELLERVIK CHRISTINA , SMITH CAREN , KILPELAINEN TUOMAS O. , CHASMAN DANIEL , FLOREZ JOSE C. 
Published: June 2018

Background: Type 2 diabetes (T2D) is a complex disease driven by lifestyle and genetic factors. The extent to which dietary fat quality may modify T2D genetic burden on the incidence of T2D is unknown.
Methods: We used Cox proportional-hazards models to calculate adjusted hazard ratios (HRs) for T2D among 103,2participants of European descent from 15 prospective cohort studies. T2D genetic risk profile was characterized by a 68-variant genetic risk score (GRS) weighted by published effect sizes. Diet was recorded using validated cohort-specific dietary assessment tools.
Findings: During a median follow-up of 12 years, 20,451 participants developed T2D. The relative risk of T2D per increment of 10 risk alleles in the GRS was 1.68 (95% confidence interval [CI] 1.62-1.74). Increasing monounsaturated fat intake in place of carbohydrates was associated with a higher risk of T2D (HR per 5% of energy 1.08, 95% CI 1.02-1.15), while increasing polyunsaturated or total ω-3 fat intake in place of carbohydrates was associated with a lower risk of T2D (HR per 5% of energy 0.92, 95% CI 0.85-1.00; and HR per increment of 1g/d 0.95, 95% CI, 0.92-0.99, respectively). We did not observe evidence of significant interactions between dietary fat subtypes and GRS on the risk of T2D.
Interpretation: In the present long-term prospective study including 103,2participants, our results support that genetic risk profile and monounsaturated fat intake were each associated with a higher risk of T2D, whereas polyunsaturated fat intake was associated with a lower risk of T2D. Findings from this study suggest that dietary fat recommendations do not need to be tailored to individual T2D genetic risk profile for the primary prevention of T2D, and that dietary fat subtypes associate with the risk of T2D across the spectrum of T2D genetic risk.

Disclosure
J. Merino: None. H.S. Dashti: None. M. Guasch: None. C. Ellervik: None. C. Smith: None. T.O. Kilpelainen: None. D. Chasman: None. J.C. Florez: Consultant; Self; Intarcia Therapeutics, Inc.. Consultant; Spouse/Partner; Santen.
Wnt Pathway Inhibitor DKK1—A Potential Novel Biomarker for Ectopic Skeletal Muscle Adiposity
Authors: ALI HIRA , ZMUDA JOSEPH M. , CVEJKUS RYAN , KERSHAW ERIN E. , KUIPERS ALLISON L. , BUNKER CLAREANN H. , MILJKOVIC IVA 
Published: June 2018

Background: Emerging evidence indicates that ectopic skeletal muscle adiposity (i.e., myosteatosis) is greater in African than in European ancestry individuals, and may be a novel risk factor contributing to increased diabetes risk. However, the biological mechanisms underlying myosteatosis are largely unknown. In vitro studies suggest that a Wnt pathway inhibitor, Dickkopf related protein 1 (DKK1), could be a novel biomarker with a role in adiposity regulation.
Methods: We measured fasting serum DKK1 in a pilot study of 159 elderly Afro-Caribbean men (mean age 63.4 years, mean BMI 27.8 kg/m2), a random subset of a population-based study comprising ∼3000 African Ancestry men with fasting morning blood collections for biomarker analyses. DKK1 was measured in duplicate in previously unthawed serum with ELISA.Also assessed were anthropometrics, DXA measured adiposity, and lower leg CT measured myosteatosis (intermuscular adiposity (mm2)) and skeletal muscle density (which reflects the intra-muscular fat content ((mg/cm3) such that greater intra-muscular adiposity reflects lower muscle density).
Results: In Spearman correlation analysis DKK1 was positively associated with BMI (R=0.19, p=0.01), waist circumference (R=0.15, p=0.05), DXA total body fat (R=0.22, p=0.004), and DXA trunk fat (R=0.19, p=0.01), independent of age. In addition, DKK1 was associated positively with intermuscular fat (R=0.19, p=0.01), and inversely with muscle density (R=-0.29, p=&lt;0.001), independent of age and BMI. No significant association was found between DKK1 and fasting serum glucose and insulin levels, and HOMA-IR.
Conclusion: Our findings suggest for the first time that lower serum levels of DKK1 may be associated with greater overall adiposity, and ectopic skeletal muscle adiposity. Further studies are needed to unravel the potential role of DKK1 in the regulation of body fat among African ancestry and other population groups with a high risk of developing obesity and related metabolic disorders.

Disclosure
H. Ali: None. J.M. Zmuda: None. R. Cvejkus: None. E.E. Kershaw: Consultant; Self; Regeneron Pharmaceuticals, Inc.. A.L. Kuipers: None. C.H. Bunker: None. I. Miljkovic: None.
IER3IP1 Regulates Beta-Cell Survival
Authors: SUN JUAN , POLONSKY KENNETH , REN DECHENG 
Published: June 2018

Mutations in the gene for Immediate Early Response 3 Interacting Protein 1 (IER3IP1) cause permanent neonatal diabetes mellitus in human. The mechanisms involved have not been determined and the role of IER3IP1 in β-cell survival has not been characterized. In order to determine if there is a molecular link between IER3IP1 deficiency and β-cell survival, we knocked down IER3IP1 gene expression in mouse MIN6 insulinoma cells. IER3IP1 suppression induced apoptotic cell death which was associated with an increase in expression of the BH3-only molecule Bim. Knockdown of Bim reduced apoptotic β-cell death induced by IER3IP1 suppression. Overexpression of the anti-apoptotic molecule Bcl-xL prevents β-cell death induced by IER3IP1 suppression. Moreover, IER3IP1 also regulates activation of the unfolded protein response (UPR). IER3IP1 suppression impairs the IRE1α and PERK arms of UPR. These results suggest that IER3IP1 suppression induces β-cell death by upregulating Bim and decreasing UPR activation. The studies in vivo also show the beta cell specific knockout IER3IP1 mice develop diabetes related to beta cell death and insulin secretion defect.

Disclosure
J. Sun: None. K. Polonsky: None. D. Ren: None.
Targeted Deletion of ATF4 in ß Cells Leads to the Vulnerability and Dedifferentiation during ER Stress
Authors: KITAKAZE KEISUKE , KURAHASHI KIYOE , MIYAKE MASATO , HAMADA YOSHIMASA , OYADOMARI MIHO , OYADOMARI SEIICHI 
Published: June 2018

ATF4 is the main transcriptional regulator of the Unfolded Protein Response (UPR) that promote restoration of normal ER function, although the contribution of ATF4 on β-cells remains poorly understood. Therefore, we developed mature β-cell specific ATF4 knockout mice (βATF4KO), were crossed with mice expressing Cre recombinase under the control of insulin promoter. ATF4-deleted β-cells were comparable to WT under normal condition but were susceptible to ER stress. To examine the role of ATF4 in vivo, we bred the Akita insulin folding mutation onto βATF4KO background. Akita/βATF4KO were dramatically compromised as shown by overt hyperglycemia in their early age and remarkable short life span due to ketoacidosis. Interestingly, we found that increased number of cells staining for glucagon, somatostatin or pancreatic polypeptide in the islets of Akita/βATF4KO, suggesting the increased β-cell dedifferentiation. We further employed the gain-of-function study using β-cell specific transgenic mice expressing Fv2E-PERK, which can activate PERK/ATF4 signaling upon addition of the artificial ligand. The induced activation of PERK/ATF4 signaling resulted in reduced insulin secretion without any sign of β-cell apoptosis. Microarray analysis revealed that several key β-cell specific transcription genes such as Pdx1 and MafA were inhibited by the activation of PERK/ATF4 signaling. We demonstrated that ATF4-deleted β-cells are more vulnerable to dedifferentiation during ER stress and excess ATF4 has inhibitory effect in β-cell function. Overall, our study has uncovered that the importance of ATF4 in governing β-cell adaptation and resilience during ER stress.

Disclosure
K. Kitakaze: None. K. Kurahashi: None. M. Miyake: None. Y. Hamada: None. M. Oyadomari: None. S. Oyadomari: None.
Targeting Cellular Calcium Homeostasis to Prevent Beta-Cell Death in Type 1 Diabetes
Authors: CLARK AMY L. , ABREU DAMIEN , BROWN CRIS M. , URANO FUMIHIKO 
Published: June 2018

Cytokines are important mediators of beta cell death leading to type 1 diabetes (T1DM). The mechanism of cytokine-mediated beta cell death has been previously shown to involve alterations in beta cell calcium homeostasis and increases in endoplasmic reticulum (ER) stress. Our group has previously established that pharmacologic modulation of cellular calcium levels with dantrolene and sitagliptin can significantly decrease cytokine and ER stress-mediated activation of the calpain and thioredoxin interacting protein pro-apoptotic pathways and suppress cell death in vitro using INS-1E rat insulinoma cells.
The current study was designed to determine if dantrolene and sitagliptin can prevent beta cell death and diabetes in the low dose streptozotocin (STZ) model of T1DM. Male C57Bl/6 mice were treated with 5 doses of STZ (50 mg/kg) daily by 10 days of intraperitoneal (IP) injections of placebo, dantrolene, or sitagliptin. Blood sugar was monitored via tail vein blood using a glucometer. Blood glucose and insulin levels in response to 2g/kg IP dextrose injection were obtained on day 10. Unmethylated insulin DNA was also measured from plasma drawn on day 0, 8 and 15 to monitor beta cell death.
Sitagliptin treated mice were resistant to low dose STZ induced diabetes as indicated by lower random blood glucose levels and normalization of blood glucose and insulin levels in response to IP dextrose infusion compared to placebo treated animals. In addition, sitagliptin treated animals had significantly lower levels of circulating unmethylated insulin DNA suggesting lower incidence of beta cell death as compared to placebo treated animals.
In summary, in the low dose STZ model of diabetes, sitagliptin lowered random blood sugar, normalized blood glucose and insulin response to IP glucose tolerance testing and significantly decreased STZ mediated beta cell death. This study supports further study on the effect of sitagliptin and DPP-4 inhibition on beta cell function and survival in T1DM.

Disclosure
A.L. Clark: None. D. Abreu: None. C.M. Brown: None. F. Urano: Research Support; Self; Eli Lilly and Company. Stock/Shareholder; Self; CytRx.
Role of NumbL:Mig6 Interactions in Beta-Cell Death during Glucolipotoxicity
Authors: BASAVARAJAPPA HALESHA D. , IRIMIA-DOMINGUEZ JOSE M. , FUEGER PATRICK T. 
Published: June 2018

As the development of type 2 diabetes (T2D) requires a loss of functional beta cell mass, preserving functional beta cell mass is essential for preventing T2D. We have focused our efforts on EGF receptor (EGFR) signaling because it controls cellular proliferation, survival, and repair mechanisms—all features relevant to maintaining beta cell mass—and is dampened during glucolipotoxic conditions (GLT) similar to those in T2D. We have established that Mig6, an endogenous feedback inhibitor of EGFR, is induced in both rodent islets cultured in GLT and human T2D islets. In addition, GLT impairs EGFR signaling in rodent and human islets. Further, Mig6 overexpression promotes apoptosis in both rodent beta cell lines and islets. Because Mig6 is an adapter protein and likely functions as a molecular scaffold, here we aimed to define the molecular mechanisms of Mig6 in GLT by identifying the interacting partners of Mig6. We performed mass spectrometry analysis using low-level, flag-tagged Mig6 expression with immunoprecipitation from Ins1-derived 832/13 cells cultured in normal conditions and GLT. We identified that Mig6 interacted with Numb and NumbL, regulators of Notch signaling, in a context dependent manner. Specifically, Mig6 interacted with Numb and NumbL in normal glucose conditions whereas these interactions were disrupted by GLT. However, roles for Numb and NumbL in beta cell function or death are largely unknown. We observed that Numb and NumbL are expressed in both rodent and human islets, and whereas their expression is not altered in GLT, their localization and aforementioned interactions were. To examine their impact in beta cell death, we used siRNA-mediated suppression of Numb and NumbL in 832/13 cells during control and GLT conditions. Whereas Numb suppression had no effect, NumbL suppression reduced apoptosis in GLT. These results suggest that NumbL plays an important role in beta cell survival. Hence, the differential interactions of Mig6 and NumbL may determine beta cell fate during stress.

Disclosure
H.D. Basavarajappa: None. J.M. Irimia-Dominguez: None. P.T. Fueger: None.
Use of Live Murine Pancreatic Slices for the Study of ß-Cell Regeneration
Authors: QADIR FAHD , WEITZ JONATHAN , ALVAREZ-CUBELA SILVIA , KLEIN DAGMAR , LANZONI GIACOMO , GARCIA-SANTANA CARLOS A. , MONTALVO ABELARDO , RICORDI CAMILLO , INVERARDI LUCA , CAICEDO ALEJANDRO , PASTORI RICARDO , DOMÍNGUEZ-BENDALA JUAN 
Published: June 2018

Introduction: Bone morphogenetic protein 7 (BMP-7), a protein with BMP-activating and TGF-β inactivating properties, induces the proliferation of a unique population of progenitor-like cells characterized by the expression of PDX1 and the BMP receptor activin-like kinase 3 (ALK3/BMPR1A). These cells can be sorted using ALK3 and the purinergic receptor P2Y1 (P2RY1) as a novel surrogate surface marker for PDX1. Sorted P2RY1+/ALK3bright+ cells form BMP-7 expandable colonies. Upon BMP-7 withdrawal, they differentiate into cells of all three lineages (endocrine, acinar and ductal) of the adult pancreas. PDX1+/ALK3+ cells absent from islets are represented in the major pancreatic ducts and pancreatic duct glands. Preliminary evidence indicates that these cells are also present in the murine pancreas. We hypothesized that islet β-cell regeneration could be studied in real time using live murine pancreatic slices transduced with a loxP-dsRed-loxP-EGFP reporter + insulin promoter-Cre adenovirus. If new β-cells arise from preexisting insulin-expressing-cells they would remain green. However, if neogenesis occurs from non-β-cells, there is a window of time during which the degrading red and the new green protein co-localize in the cell. Allowing us to discriminate between neogenesis and β-cell proliferation.
Methods: Low melting point (LMP) agarose-embedded, vibratome-sectioned live pancreatic slices were generated from CD-1 mice. Transduction with a loxP-dsRed-loxP-EGFP reporter + insulin promoter-Cre adenovirus was done in slices cultured atop optically clear membranes. Slices were treated for 4 days with an ALK3 agonist (THR-123) or saline at the same time of the co-transduction. Bright field and fluorescence images of them were taken every 24h for 7 days.
Conclusions: This is the first report on the use of live pancreatic slices as a novel tool for the study of pancreatic regeneration. Our preliminary results suggest that there are quantifiable β-cell neogenic events in response to BMP-7-like agents.

Disclosure
F. Qadir: None. J. Weitz: None. S. Alvarez-Cubela: None. D. Klein: None. G. Lanzoni: None. C.A. Garcia-Santana: Employee; Self; Ophysio Incorporated. A. Montalvo: None. C. Ricordi: None. L. Inverardi: None. A. Caicedo: None. R. Pastori: None. J. Domínguez-Bendala: Stock/Shareholder; Self; Ophysio.
E-Cadherin Downregulation by Cathepsin L Plays a Role in the Proliferation of Insulin-Producing Cells following Inhibition of Serpin B13
Authors: LO CHI-WEN , SHEU TZONG-JEN , CZYZYK JAN 
Published: June 2018

Experimental targeting of the exocrine pancreatic ductal tree stimulates beta-cell rejuvenation thereby underscoring the importance of functional crosstalk between the exocrine and endocrine pancreas. We recently found that antibody directed against serpin B13, a protease inhibitor expressed in the ductal epithelium of the exocrine pancreas, increased the catalytic activity of it’s protease target, cathepsin L (CatL) and subsequently upregulated Reg-mediated cellular proliferation in the islets. However, the exact molecular events that link catL activity to upregulated Reg and islet cell proliferation remain unclear. As increased E-cadherin levels during islet formation mediate a decline in beta-cell proliferation, and Reg upregulation has been linked to activation of beta-catenin, we hypothesized that the functional crosstalk between pancreatic ductal epithelium and the islets may involve CatL-mediated activation of the E-cadherin/β-catenin pathway. In support of this we found that E-cadherin was downregulated with a concomitant increase in Reg1 in mice treated with serpin B13 monoclonal antibody (mAb). Likewise, exposure to recombinant CatL or ductal epithelium extract treated with serpin B13 mAb caused decreased E-cadherin expression in the pancreatic islets during in vitro culture. On the other hand, this expression was recovered with CatL inhibitor. Moreover, treatment of MIN-6 insulinoma cells with ductal epithelium extract and serpin B13 mAb stimulated intranuclear accumulation of β-catenin, while Reg gene expression in the islets was markedly reduced in the presence of the β-catenin chemical inhibitor, FH535. These data establish E-cadherin as a potential target of CatL in the regulation of islet cell proliferation by an immunological response to serpin B13, and implicate the E-cadherin/β-catenin pathway as an islet sensing mechanism of the signals that are generated in the pancreatic exocrine milieu.

Disclosure
C. Lo: None. T. Sheu: None. J. Czyzyk: None.
GLP-1 Controls Pancreatic Endocrine Development
Authors: CRAS-MÉNEUR CORENTIN M.H. , SEELEY RANDY J. 
Published: June 2018

Glucagon-like peptide 1 (GLP-1) has been successfully leveraged as a treatment of type 2 diabetes mellitus. Its beneficial effects on β-cell growth and function are documented in the adult rodents but its role during pancreatic organogenesis remains unexplored. GLP-1 has numerous targets in vivo and has been shown to regulate key signaling pathways in β-cells. In the mature islets, GLP-1 modulates the MAPK and Akt signaling pathways, controls glucose sensing and responsiveness and increases Pdx-1 levels. All these processes are also known to be instrumental in the regulation of the proper growth, differentiation and maturation of the early endocrine progenitors. A few studies indirectly implied that GLP-1 could also have some impact on pancreatic organogenesis, promoting endocrine development in in vitro models. However, adult GLP-1 receptor (GLP-1R) knock out mice only display mild metabolic impairments mostly triggered by exposure to high-fat diet, but the phenotype of these animals had not been studied during early development.
Using our total body knockout of the GLP-1 receptor, we found that total size of the pancreas of the newborn knocked-out animals appears to be reduced at birth and the β-cell mass is diminished by 89%. These results support that GLP-1R signaling is crucial for normal pancreatic development but that catch up growth can takes place between birth and adulthood to compensate for reduced GLP-1R signaling. These data illustrate that in addition to its insulinotropic effects in mature islets, GLP-1 signaling plays a central role during pancreatic development and the acquisition of a normal β-cell mass.

Disclosure
C.M.H. Cras-Méneur: None. R.J. Seeley: Research Support; Self; Novo Nordisk Inc., Novo Nordisk Inc., Ethicon US, LLC.. Consultant; Self; Janssen Pharmaceuticals, Inc.. Research Support; Self; Zafgen, MedImmune. Consultant; Self; Kallyope, Scohia.
Glis3 Regulates Pancreatic ß-Cell Development in Part through Coordination with Other Islet Transcription Factors
Authors: SCOVILLE DAVID 
Published: June 2018

Pancreatic β-cells play a central role in regulating glucose homeostasis. One prominent regulator of both β-cell fate and function is Glis3, a transcription factor with both co-activating and co-repressive roles. Both humans and mice lacking a functional copy of Glis3 are diabetic from birth, with a near complete absence of β-cells. Interestingly, Glis3 is expressed relatively early during pancreas development prior to the differentiation of ductal and endocrine cells from a common lineage, and is maintained in both β-cells as well as ductal cells. Furthermore, postnatal deletion of Glis3 also results in hyperglycemia, suggesting Glis3 as a critical regulator of postnatal β-cell function as well. Yet, while much is known about the phenotype of Glis3 deletions, little is known about its molecular function.
My research focuses on how Glis3 regulates β-cell development and function. To determine which genes are regulated by Glis3, a mouse model with a pancreas-specific deletion of Glis3 was utilized. RNA-seq analysis of isolated islets revealed a large number of both upregulated and downregulated genes, and ChIP-seq analysis of Glis3 in islets revealed many of these genes are direct targets of Glis3 regulation. Interestingly, Glis3 binding largely overlaps with binding of the transcription factor Nkx6.1, and partially overlaps with transcription factors Pdx1 and Nkx2.2, but shows less overlap with other islet-enriched transcription factors. This indicates that Glis3 could function in distinct regulatory complexes, and that better understanding of Glis3 gene regulation within the pancreatic β-cell will lead to a better understanding of how β-cell fate is controlled and maintained, as well as which genes are essential for postnatal function.

Disclosure
D. Scoville: None.