Browsing by Subject "Glucose"
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Item 12-Lipoxygenase Inhibitor Improves Functions of Cytokine-Treated Human Islets and Type 2 Diabetic Islets(Oxford University Press, 2017-08-01) Ma, Kaiwen; Xiao, An; Park, So Hyun; Glenn, Lindsey; Jackson, Laura; Barot, Tatvam; Weaver, Jessica R.; Taylor-Fishwick, David A.; Luci, Diane K.; Maloney, David J.; Mirmira, Raghavendra G.; Imai, Yumi; Nadler, Jerry L.; Pediatrics, School of MedicineContext: The 12-lipoxygenase (12-LO) pathway produces proinflammatory metabolites, and its activation is implicated in islet inflammation associated with type 1 and type 2 diabetes (T2D). Objectives: We aimed to test the efficacy of ML355, a highly selective, small molecule inhibitor of 12-LO, for the preservation of islet function. Design: Human islets from nondiabetic donors were incubated with a mixture of tumor necrosis factor α , interluekin-1β, and interferon-γ to model islet inflammation. Cytokine-treated islets and human islets from T2D donors were incubated in the presence and absence of ML355. Setting: In vitro study. Participants: Human islets from organ donors aged >20 years of both sexes and any race were used. T2D status was defined from either medical history or most recent hemoglobin A1c value >6.5%. Intervention: Glucose stimulation. Main Outcome Measures: Static and dynamic insulin secretion and oxygen consumption rate (OCR). Results: ML355 prevented the reduction of insulin secretion and OCR in cytokine-treated human islets and improved both parameters in human islets from T2D donors. Conclusions: ML355 was efficacious in improving human islet function after cytokine treatment and in T2D islets in vitro. The study suggests that the blockade of the 12-LO pathway may serve as a target for both form of diabetes and provides the basis for further study of this small molecule inhibitor in vivo.Item Accurate and sensitive quantitation of glucose and glucose phosphates derived from storage carbohydrates by mass spectrometry(Elsevier, 2020-02-15) Young, Lyndsay E.A.; Brizzee, Corey O.; Macedo, Jessica K. A.; Murphy, Robert D.; Contreras, Christopher J.; DePaoli-Roach, Anna A.; Roach, Peter J.; Gentry, Matthew S.; Sun, Ramon C.; Biochemistry and Molecular Biology, School of MedicineThe addition of phosphate groups into glycogen modulates its branching pattern and solubility which all impact its accessibility to glycogen interacting enzymes. As glycogen architecture modulates its metabolism, it is essential to accurately evaluate and quantify its phosphate content. Simultaneous direct quantitation of glucose and its phosphate esters requires an assay with high sensitivity and a robust dynamic range. Herein, we describe a highly-sensitive method for the accurate detection of both glycogen-derived glucose and glucose-phosphate esters utilizing gas-chromatography coupled mass spectrometry. Using this method, we observed higher glycogen levels in the liver compared to skeletal muscle, but skeletal muscle contained many more phosphate esters. Importantly, this method can detect femtomole levels of glucose and glucose phosphate esters within an extremely robust dynamic range with excellent accuracy and reproducibility. The method can also be easily adapted for the quantification of plant starch, amylopectin or other biopolymers.Item The altered mononuclear cell-derived cytokine response to glucose ingestion is not regulated by excess adiposity in polycystic ovary syndrome(The Endocrine Society, 2014-11) González, Frank; Sia, Chang Ling; Shepard, Marguerite K.; Rote, Neal S.; Minium, Judi; Department of Obstetrics & Gynecology, IU School of MedicineCONTEXT: Excess adipose tissue is a source of inflammation. Polycystic ovary syndrome (PCOS) is a proinflammatory state and is often associated with excess abdominal adiposity (AA) alone and/or frank obesity. OBJECTIVE: To determine the effect of glucose ingestion on cytokine release from mononuclear cells (MNC) in women with PCOS with and without excess AA and/or obesity. DESIGN: A cross-sectional study. SETTING: Academic medical center. PATIENTS: Twenty-three women with PCOS (seven normal weight with normal AA, eight normal weight with excess AA, eight obese) and 24 ovulatory controls (eight normal weight with normal AA, eight normal weight with excess AA, eight obese). INTERVENTION: Three-hour 75-g oral glucose tolerance test (OGTT). MAIN OUTCOME MEASURES: Body composition was measured by dual energy x-ray absorptiometry. Insulin sensitivity was derived from the OGTT (ISOGTT). TNFα, IL-6, and IL-1β release was measured in supernatants of cultured MNC isolated from blood samples drawn while fasting and 2 hours after glucose ingestion. RESULTS: Insulin sensitivity was lower in obese subjects regardless of PCOS status and in normal-weight women with PCOS compared with normal-weight controls regardless of body composition status. In response to glucose ingestion, MNC-derived TNFα, IL-6, and IL-1β release decreased in both normal-weight control groups but failed to suppress in either normal-weight PCOS group and in obese women regardless of PCOS status. For the combined groups, the cytokine responses were negatively correlated with insulin sensitivity and positively correlated with abdominal fat and androgens. CONCLUSIONS: Women with PCOS fail to suppress MNC-derived cytokine release in response to glucose ingestion, and this response is independent of excess adiposity. Nevertheless, a similar response is also a feature of obesity per se. Circulating MNC and excess adipose tissue are separate and distinct sources of inflammation in this population.Item Aspects of regulation of hepatic metabolism(1979) Ochs, RaymonItem Assessment and Management of Hypertension among Patients on Peritoneal Dialysis(American Society of Nephrology., 2019-02-07) Vaios, Vasilios; Georgianos, Panagiotis I.; Liakopoulos, Vassilios; Agarwal, Rajiv; Medicine, School of MedicineApproximately 7%-10% of patients with ESKD worldwide undergo peritoneal dialysis (PD) as kidney replacement therapy. The continuous nature of this dialytic modality and the absence of acute shifts in pressure and volume parameters is an important differentiation between PD and in-center hemodialysis. However, the burden of hypertension and prognostic association of BP with mortality follow comparable patterns in both modalities. Although management of hypertension uses similar therapeutic principles, long-term preservation of residual diuresis and longevity of peritoneal membrane function require particular attention in the prescription of the appropriate dialysis regimen among those on PD. Dietary sodium restriction, appropriate use of icodextrin, and limited exposure of peritoneal membrane to bioincompatible solutions, as well as adaptation of the PD regimen to the peritoneal transport characteristics, are first-line therapeutic strategies to achieve adequate volume control with a potential long-term benefit on technique survival. Antihypertensive drug therapy is a second-line therapeutic approach, used when BP remains unresponsive to the above volume management strategies. In this article, we review the available evidence on epidemiology, diagnosis, and treatment of hypertension among patients on PD and discuss similarities and differences between PD and in-center hemodialysis. We conclude with a call for randomized trials aiming to elucidate several areas of uncertainty in management of hypertension in the PD population.Item Associations among osteocalcin, leptin and metabolic health in children ages 9-13 years in the United States(BioMed Central, 2017-03-07) Virecoulon Giudici, Kelly; Kindler, Joseph M.; Martin, Berdine R.; Laing, Emma M.; McCabe, George P.; McCabe, Linda D.; Hausman, Dorothy B.; Martini, Lígia Araújo; Lewis, Richard D.; Weaver, Connie M.; Peacock, Munro; Hill Gallant, Kathleen M.; Department of Medicine, IU School of MedicineBACKGROUND: This study aimed to investigate the relationships among osteocalcin, leptin and metabolic health outcomes in children ages 9-13 years. METHODS: This was a cross-sectional analysis of baseline data from 161 boys and 157 girls (ages 9-13 years) who previously participated in a double-blinded randomized placebo controlled trial of vitamin D supplementation. Relationships among fasting serum total osteocalcin (tOC), undercarboxylated osteocalcin (ucOC), leptin, and metabolic health outcomes were analyzed. RESULTS: Approximately 52% of study participants were obese based on percent body fat cutoffs (>25% for boys and >32% for girls) and about 5% had fasting serum glucose within the prediabetic range (i.e. 100 to 125 mg/dL). Serum tOC was not correlated with leptin, glucose, insulin, HOMA-IR, or HOMA-β after adjusting for percent body fat. However, serum ucOC negatively correlated with leptin (partial r = -0.16; p = 0.04) and glucose (partial r = -0.16; p = 0.04) after adjustment for percent body fat. Leptin was a positive predictor of insulin, glucose, HOMA-IR, and HOMA-β after adjusting for age, sex and percent body fat (all p < 0.001). CONCLUSIONS: These data depict an inverse relationship between leptin and various metabolic health outcomes in children. However, the notion that tOC or ucOC link fat with energy metabolism in healthy children was not supported.Item Biomarker Risk Score Algorithm and Preoperative Stratification of Patients with Pancreatic Cystic Lesions(Wolters Kluwer, 2021) Yip-Schneider, Michele T.; Wu, Huangbing; Allison, Hannah R.; Easler, Jeffrey J.; Sherman, Stuart; Al-Haddad, Mohammad A.; Dewitt, John M.; Schmidt, C. Max; Surgery, School of MedicineBackground: Pancreatic cysts are incidentally detected in up to 13% of patients undergoing radiographic imaging. Of the most frequently encountered types, mucin-producing (mucinous) pancreatic cystic lesions may develop into pancreatic cancer, while nonmucinous ones have little or no malignant potential. Accurate preoperative diagnosis is critical for optimal management, but has been difficult to achieve, resulting in unnecessary major surgery. Here, we aim to develop an algorithm based on biomarker risk scores to improve risk stratification. Study design: Patients undergoing surgery and/or surveillance for a pancreatic cystic lesion, with diagnostic imaging and banked pancreatic cyst fluid, were enrolled in the study after informed consent (n = 163 surgical, 67 surveillance). Cyst fluid biomarkers with high specificity for distinguishing nonmucinous from mucinous pancreatic cysts (vascular endothelial growth factor [VEGF], glucose, carcinoembryonic antigen [CEA], amylase, cytology, and DNA mutation) were selected. Biomarker risk scores were used to design an algorithm to predict preoperative diagnosis. Performance was tested using surgical (retrospective) and surveillance (prospective) cohorts. Results: In the surgical cohort, the biomarker algorithm outperformed the preoperative clinical diagnosis in correctly predicting the final pathologic diagnosis (91% vs 73%; p < 0.000001). Specifically, nonmucinous serous cystic neoplasms (SCN) and mucinous cystic neoplasms (MCN) were correctly classified more frequently by the algorithm than clinical diagnosis (96% vs 30%; p < 0.000008 and 92% vs 69%; p = 0.04, respectively). In the surveillance cohort, the algorithm predicted a preoperative diagnosis with high confidence based on a high biomarker score and/or consistency with imaging from ≥1 follow-up visits. Conclusions: A biomarker risk score-based algorithm was able to correctly classify pancreatic cysts preoperatively. Importantly, this tool may improve initial and dynamic risk stratification, reducing overdiagnosis and underdiagnosis.Item Checkpoint kinase 2 controls insulin secretion and glucose homeostasis(Springer Nature, 2024) Chong, Angie Chi Nok; Vandana, J. Jeya; Jeng, Ginnie; Li, Ge; Meng, Zihe; Duan, Xiaohua; Zhang, Tuo; Qiu, Yunping; Duran-Struuck, Raimon; Coker, Kimberly; Wang, Wei; Li, Yanjing; Min, Zaw; Zuo, Xi; de Silva, Neranjan; Chen, Zhengming; Naji, Ali; Hao, Mingming; Liu, Chengyang; Chen, Shuibing; Urology, School of MedicineAfter the discovery of insulin, a century ago, extensive work has been done to unravel the molecular network regulating insulin secretion. Here we performed a chemical screen and identified AZD7762, a compound that potentiates glucose-stimulated insulin secretion (GSIS) of a human β cell line, healthy and type 2 diabetic (T2D) human islets and primary cynomolgus macaque islets. In vivo studies in diabetic mouse models and cynomolgus macaques demonstrated that AZD7762 enhances GSIS and improves glucose tolerance. Furthermore, genetic manipulation confirmed that ablation of CHEK2 in human β cells results in increased insulin secretion. Consistently, high-fat-diet-fed Chk2-/- mice show elevated insulin secretion and improved glucose clearance. Finally, untargeted metabolic profiling demonstrated the key role of the CHEK2-PP2A-PLK1-G6PD-PPP pathway in insulin secretion. This study successfully identifies a previously unknown insulin secretion regulating pathway that is conserved across rodents, cynomolgus macaques and human β cells in both healthy and T2D conditions.Item Comment on Liu et al. Aberrant Expression of FBXO2 Disrupts Glucose Homeostasis Through Ubiquitin-Mediated Degradation of Insulin Receptor in Obese Mice. Diabetes 2017;66:689–698(American Diabetes Association, 2020-02) Wong, Siauyen; Nelson, Rick F.; Lu, Peiran; Paulson, Henry; Lin, Dingbo; Otolaryngology -- Head and Neck Surgery, School of MedicineItem Comparisons of Metabolic Measures to Predict T1D vs Detect a Preventive Treatment Effect in High-Risk Individuals(Oxford University Press, 2024) Sims, Emily K.; Cuthbertson, David; Jacobsen, Laura; Ismail, Heba M.; Nathan, Brandon M.; Herold, Kevan C.; Redondo, Maria J.; Sosenko, Jay; Pediatrics, School of MedicineContext: 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.