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Sample records for biphasic human insulin

  1. Biphasic Insulin Analogues in Type 2 Diabetes: Expert Panel Recommendations

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    Sema Akalın

    2011-09-01

    Full Text Available Recently, the prevalence of type 2 diabetes has reached pandemic levels all over the world, and the problem is still growing. Type 2 diabetes is a progressive disease, in which insulin resistance and decrease in beta cell function accompany obesity. Early disorder, which ensues in clinical progression of the disease, is the defect of early phase insulin secretion. Patients have already lost approximately half of their beta cell reserve at the time of diagnosis. Aims of type 2 diabetes treatment are to eliminate hyperglycemia caused by insufficient insulin secretion and/or insulin resistance, to slow down beta cell destruction/depletion, to improve concomitant metabolic problems and to prevent complications. In treatment algorithms, insulin is evaluated as a replacement therapy at the following stage after life style changes (medical nutrition therapy, exercise and oral anti-diabetic drugs (OADs options. Since beta cell depletion is present at initial stages of the disease, it transforms insulin therapy into an earlier approach in treatment stages. Premixed insulin forms are one of the proposed treatment options in patients with hyperglycemia that is not controlled by OADs. These types of insulins are developed to meet both basal and postprandial insulin requirements of patients. Currently, premixed human insulin forms are replaced by analogue insulin forms, which can mimic the physiological secretion in more acceptable manner. Biphasic analogue insulin is one of the readily available pre-mixed analogue insulin forms, an example of this, Biphasic Insulin aspart 30 which is the one of the premixed analoge insulin forms, contains 30% insulin aspart and 70% protaminated insulin aspart. Consensus recommending the individualized approach in insulin therapy implies that physicians should have more detailed information about the use of different insulin forms. Although a global consensus report about initiation, titration and intensification and the use

  2. Switching from human insulin to biphasic insulin aspart 30 treatment gets more patients with type 2 diabetes to reach target glycosylated hemoglobin 《7%: the results from the China cohort of the PRESENT study

    Institute of Scientific and Technical Information of China (English)

    GAO Yan; GUO Xiao-hui

    2010-01-01

    Background The clinical importance of glycaemic control in patients with diabetes has been well established. This study aimed to explore twice-daily biphasic insulin aspart 30 (BIAsp 30) for insulin initiation in patients with type 2 diabetes mellitus (T2DM) who had poor glycaemic control with human insulins (His). We use data from a Chinese cohort of the PRESENT study.Methods In the 3-month study, Chinese subjects with T2DM started insulin therapy with BIAsp 30 in routine care. Glycaemic control was measured by glycosylated hemoglobin (HbA1c), fasting plasma glucose (FPG) and posting plasma glucose (PPG). The safety assessment included hypoglycaemia and other adverse events.Results A total of 1989 subjects previously treated with His were switched to BIAsp 30 for 3-month treatment. Mean HbA1c, FPG and PPG were significantly improved after the therapy. The overall rate of hypoglycaemia decreased at the end of the trial except for the patients previously treated with long-acting insulin. Most of the events were minor and diurnal hypoglycaemia. Only one serious adverse drug reaction (SADR), a local hypersensitivity, was reported. The majority of the patients (296.7%) and physicians (≥84.7%) were either satisfied or very satisfied with the treatment using BIAsp 30 compared with previous HI therapy.Conclusion The BIAsp 30 treatment improved both glycaemic control and patients' satisfaction without increasing hypoglycaemia in T2DM subjects inadequately controlled by Hls.

  3. Bioavailability and variability of biphasic insulin mixtures

    DEFF Research Database (Denmark)

    Søeborg, Tue; Rasmussen, Christian Hove; Mosekilde, Erik

    2012-01-01

    , the absorption kinetics for mixtures of insulins is described. This requires that the bioavailability of the different insulins is considered. A short review of insulin bioavailability and a description of the subcutaneous depot thus precede the presentation of possible mechanisms associated with subcutaneous...... mixtures. The results can be used in both the development of novel insulin products and in the planning of the treatment of insulin dependent diabetic patients....

  4. Efficacy and safety of biphasic insulin aspart and biphasic insulin lispro mix in patients with type 2 diabetes: A review of the literature

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    Ajay Kumar

    2016-01-01

    Full Text Available Type 2 diabetes (T2D represents an escalating burden worldwide, particularly in China and India. Compared with Caucasians, Asian people with diabetes have lower body mass index, increased visceral adiposity, and postprandial glucose (PPG/insulin resistance. Since postprandial hyperglycemia contributes significantly to total glycemic burden and is associated with heightened cardiovascular risk, targeting PPG early in T2D is paramount. Premixed insulin regimens are widely used in Asia due to their convenience and effectiveness. Data from randomized controlled trials and observational studies comparing efficacy and safety of biphasic insulin aspart 30 (BIAsp 30 with biphasic insulin lispro mix (LM 25/50 and versus other insulin therapies or oral antidiabetic drugs (OADs in T2D demonstrated that BIAsp 30 and LM 25/50 were associated with similar or greater improvements in glycemic control versus comparator regimens, such as basal–bolus insulin, in insulin-naÏve, and prior insulin users. Studies directly comparing BIAsp 30 and LM 25 provided conflicting glycemic control results. Safety data generally showed increased hypoglycemia and weight gain with premixed insulins versus basal–bolus insulin or OADs. However, large observational trials documented improvements in glycated hemoglobin, PPG, and hypoglycemia with BIAsp 30 in multi-ethnic patient populations. In summary, this literature review demonstrates that premixed insulin regimens are an appropriate and effective treatment choice in T2D.

  5. Comparison of a soluble co-formulation of insulin degludec/insulin aspart vs biphasic insulin aspart 30 in type 2 diabetes

    DEFF Research Database (Denmark)

    Niskanen, Leo; Leiter, Lawrence A; Franek, Edward;

    2012-01-01

    Insulin degludec/insulin aspart (IDegAsp) is a soluble co-formulation of insulin degludec (70%) and insulin aspart (IAsp: 30%). Here, we compare the efficacy and safety of IDegAsp, an alternative IDegAsp formulation (AF: containing 45% IAsp), and biphasic IAsp 30 (BIAsp 30)....

  6. Clinical experience with insulin detemir, biphasic insulin aspart and insulin aspart in people with type 2 diabetes: Results from the Hyderabad cohort of the A1chieve study

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    Santosh, R.; Mehrotra, Ravi; Sastry, N. G.

    2013-01-01

    Background: The A1chieve, a multicentric (28 countries), 24-week, non-interventional study evaluated the safety and effectiveness of insulin detemir, biphasic insulin aspart and insulin aspart in people with T2DM (n = 66,726) in routine clinical care across four continents. Materials and Methods: Data was collected at baseline, at 12 weeks and at 24 weeks. This short communication presents the results for patients enrolled from Hyderabad, India. Results: A total of 1249 patients were enrolled in the study. Four different insulin analogue regimens were used in the study. Patients had started on or were switched to biphasic insulin aspart (n = 893), insulin detemir (n = 158), insulin aspart (n = 124), basal insulin plus insulin aspart (n = 19) and other insulin combinations (n = 54). At baseline glycaemic control was poor for both insulin naïve (mean HbA1c: 9.0%) and insulin user (mean HbA1c: 9.5%) groups. After 24 weeks of treatment, both the groups showed improvement in HbA1c (insulin naïve: −0.9%, insulin users: −1.1%). SADRs including major hypoglycaemic events or episodes did not occur in any of the study patients. Conclusion: Starting or switching to insulin analogues was associated with improvement in glycaemic control with a low rate of hypoglycaemia. PMID:24404501

  7. Clinical experience with insulin detemir, biphasic insulin aspart and insulin aspart in people with type 2 diabetes: Results from the Karnataka cohort of the A 1 chieve study

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    Neeta Deshpande

    2013-01-01

    Full Text Available Background: The A 1 chieve, a multicentric (28 countries, 24-week, non-interventional study evaluated the safety and effectiveness of insulin detemir, biphasic insulin aspart and insulin aspart in people with T2DM (n = 66,726 in routine clinical care across four continents. Materials and Methods: Data was collected at baseline, at 12 weeks and at 24 weeks. This short communication presents the results for patients enrolled from Karnataka, India. Results: A total of 2243 patients were enrolled in the study. Four different insulin analogue regimens were used in the study. Patients had started on or were switched to biphasic insulin aspart (n = 1855, insulin detemir (n = 211, insulin aspart (n = 111, basal insulin plus insulin aspart (n = 16 and other insulin combinations (n = 40. At baseline glycaemic control was poor for both insulin naïve (mean HbA 1 c: 9.2% and insulin user (mean HbA 1 c: 9.0% groups. After 24 weeks of treatment, both the groups showed improvement in HbA 1 c (insulin naïve: −1.4%, insulin users: −1.7%. SADRs including major hypoglycaemic events or episodes did not occur in any of the study patients. Conclusion: Starting or switching to insulin analogues was associated with improvement in glycaemic control with a low rate of hypoglycaemia.

  8. Clinical experience with insulin detemir, biphasic insulin aspart and insulin aspart in people with type 2 diabetes: Results from the Kerala cohort of the A 1 chieve study

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    Sreejith N Kumar

    2013-01-01

    Full Text Available Background: The A 1 chieve, a multicentric (28 countries, 24-week, non-interventional study evaluated the safety and effectiveness of insulin detemir, biphasic insulin aspart and insulin aspart in people with T2DM (n = 66,726 in routine clinical care across four continents. Materials and Methods: Data was collected at baseline, at 12 weeks and at 24 weeks. This short communication presents the results for patients enrolled from Kerala, India. Results: A total of 1732 patients were enrolled in the study. Four different insulin analogue regimens were used in the study. Patients had started on or were switched to biphasic insulin aspart (n = 1203, insulin detemir (n = 212, insulin aspart (n = 312, basal insulin plus insulin aspart (n = 1 and other insulin combinations (n = 1. At baseline glycaemic control was poor for both insulin naïve (mean HbA 1 c: 10.0% and insulin user (mean HbA 1 c: 8.3% groups. After 24 weeks of treatment, both the groups showed improvement in HbA 1 c (insulin naïve: −2.4%, insulin users: −0.5%. SADRs including major hypoglycaemic events or episodes did not occur in any of the study patients. Conclusion: Starting or switching to insulin analogues was associated with improvement in glycaemic control with a low rate of hypoglycaemia.

  9. Clinical experience with insulin detemir, biphasic insulin aspart and insulin aspart in people with type 2 diabetes: Results from the Rajasthan cohort of the A 1 chieve study

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    Akhil Joshi

    2013-01-01

    Full Text Available Background: The A 1 chieve, a multicentric (28 countries, 24-week, non-interventional study evaluated the safety and effectiveness of insulin detemir, biphasic insulin aspart and insulin aspart in people with T2DM (n = 66,726 in routine clinical care across four continents. Materials and Methods: Data was collected at baseline, at 12 weeks and at 24 weeks. This short communication presents the results for patients enrolled from Rajasthan, India. Results: A total of 477 patients were enrolled in the study. Four different insulin analogue regimens were used in the study. Patients had started on or were switched to biphasic insulin aspart (n = 340, insulin detemir (n = 90, insulin aspart (n = 37, basal insulin plus insulin aspart (n = 7 and other insulin combinations (n = 2. At baseline glycaemic control was poor for both insulin naïve (mean HbA 1 c: 8.3% and insulin user (mean HbA 1 c: 8.4% groups. After 24 weeks of treatment, both the groups showed improvement in HbA 1 c (insulin naïve: −0.9%, insulin users: −1.2%. Major hypoglycaemic events decreased from 0.5 events/patient-year to 0.0 events/patient-year in insulin naïve group while no change from baseline (1.3 events/patients-year was observed for insulin users. SADRs were not reported in any of the study patients. Conclusion: Starting or switching to insulin analogues was associated with improvement in glycaemic control with a low rate of hypoglycaemia.

  10. P-glycoprotein regulating biphasic insulin secretion in rat pancreatic beta cells

    Institute of Scientific and Technical Information of China (English)

    TANG Yun-zhao; LI Dai-qing; SUN Fu-jun; LI Li; YU De-min

    2009-01-01

    Background A 65-kD mdr1(multi-drug resistance protein 1,P-glycoprotein)-like protein has been suggested to be the regulatory protein to the chloride channel protein 3(CIC-3)mediating insulin granules acidification and release in mouse pancreatic beta cells.But the protein has not been deeply investigated.In this study,we identified existence of the 65-kda protein in rat islets and preliminarily explored its biological functions.Methods Total RNAs of rat kidneys served as positive controls,and pancreas,islets and INS-1 cells were extracted for reverse-transcript PCR(RT-PCR),respectively.The cDNAs were run with specific primers selected from the mRNA of abcblb encoding P-glycoprotein.All PCR products were visualized in agarose gel electrophoresis and sequenced.Homogenates of rat islets and INS-1 cells were applied to SDS-PAGE.P-glycoprotein was detected by a specific monoclonal antibody,C219.Biphasic insulin release was measured in static incubations of rat islets with radioimmunology assay.Results Compared with positive control,expression of the P-glycoprotein mRNA segments were detected in the islets,INS-1 cells and pancreas.Sequence analysis confirmed that the PCR products were matched with mRNA of P-glycoprotein.A 65-kda protein was recognized by the antibody in the islets homogenate but not in that of INS-1 cells in Western-blotting.Instead,the homogenate of INS-1 cells contained a 160-kda protein recognized by the antibody.Insulin secretion of rat islets were stimulated by high glucose(16.7mmol/L),and showed biphasic curve during 60-minute incubation.After co-incubation with cyclosporine A(CsA),specific inhibitor to P-glycoprotein,the second phase of insulin secretion was reduced significantly while the first phase was not influenced.Conclusions The 65-kda protein expressed in rat islets is most likely a mini-P-glycoprotein.It may play a key role regulating biphasic insulin release.

  11. In short photoperiods, human sleep is biphasic.

    Science.gov (United States)

    Wehr

    1992-06-01

    Results of a photoperiod experiment show that human sleep can be unconsolidated and polyphasic, like the sleep of other animals. When normal individuals were transferred from a conventional 16-h photoperiod to an experimental 10-h photo-period, their sleep episodes expanded and usually divided into two symmetrical bouts, several hours in duration, with a 1-3 h waking interval between them. The durations of nocturnal melatonin secretion and of the nocturnal phase of rising sleepiness (measured in a constant routine protocol) also expanded, indicating that the timing of internal processes that control sleep and melatonin, such as circadian rhythms, had been modified by the change in photoperiod. Previous work suggests that the experimental results could be simulated with dual-oscillators, entrained separately to dawn and dusk, or with a two-process model, having a lowered threshold for sleep-onset during the scotoperiod.

  12. Clinical experience with insulin detemir, biphasic insulin aspart and insulin aspart in people with type 2 diabetes: Results from the Eastern Saudi Arabia cohort of the A 1 chieve study

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    Faisal Hashim

    2013-01-01

    Full Text Available Background: The A 1 chieve, a multicentric (28 countries, 24-week, non-interventional study evaluated the safety and effectiveness of insulin detemir, biphasic insulin aspart and insulin aspart in people with T2DM (n = 66,726 in routine clinical care across four continents. Materials and Methods: Data was collected at baseline, at 12 weeks and at 24 weeks. This short communication presents the results for patients enrolled from Eastern Saudi Arabia. Results: A total of 1040 patients were enrolled in the study. Four different insulin analogue regimens were used in the study. Study patients had started on or were switched to biphasic insulin aspart (n = 489, insulin detemir (n = 360, insulin aspart (n = 37, basal insulin plus insulin aspart (n = 96 and other insulin combinations (n = 57. At baseline glycaemic control was poor for both insulin naïve (mean HbA 1 c: 10.0% and insulin user (mean HbA 1 c: 9.2% groups. After 24 weeks of treatment, both the groups showed improvement in HbA 1 c (insulin naïve: −2.7%, insulin users: −1.7%. No major hypoglycaemic episodes were observed at 24 weeks. SADR was reported in 0.6% of insulin users. Conclusion: Starting or switching to insulin analogues was associated with improvement in glycaemic control with a low rate of hypoglycaemia.

  13. Switching from basal or basal-bolus insulin to biphasic insulin aspart 30: Results from the Indian cohort of the A 1 chieve study

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    Arpandev Bhattacharyya

    2014-01-01

    Full Text Available Aim: To determine the safety and efficacy of biphasic insulin aspart 30 (BIAsp 30 therapy in the Indian patients with type 2 diabetes previously on basal or basal-bolus insulin therapies. Materials and Methods: Patients switching from insulin glargine, neutral protamine Hagedorn (NPH insulin, or basal-bolus insulin to BIAsp 30 in the Indian cohort of the A 1 chieve study were included. Safety and efficacy of treatment was evaluated over 24 weeks. Results: A total of 422 patients (pre-study basal-bolus insulin, 49; NPH insulin, 157; insulin glargine, 216 switched to BIAsp 30. Pre-study insulin doses were 0.61 ± 0.26 U/kg, 0.34 ± 0.2 U/kg and 0.40 ± 0.21 U/kg and the mean week 24 BIAsp 30 doses were 0.50 ± 0.21 U/kg, 0.35 ± 0.15 U/kg and 0.42 ± 0.16 U/kg in the prior basal-bolus insulin, NPH insulin and insulin glargine groups, respectively. No serious adverse drug reactions, major or nocturnal hypoglycemia were reported. The proportion of patients experiencing overall hypoglycemia was significantly lower from baseline (5.6% to week 24 (1.0% in the pre-study insulin-glargine group and appeared to be lower in pre-study NPH insulin and basal-bolus insulin groups. Glycemic control improved significantly from baseline week 24 in the pre-study NPH insulin and insulin-glargine groups (P < 0.001, while it appeared to improve in the pre-study basal-bolus group. Quality of life was positively impacted after 24 weeks in all 3 groups. Conclusion: The switch from basal or basal-bolus insulin to BIAsp 30 was safe, well tolerated and improved the glycemic control in this Indian cohort.

  14. Switching from basal or basal-bolus insulin to biphasic insulin aspart 30: Results from the Indian cohort of the A1 chieve study

    Science.gov (United States)

    Bhattacharyya, Arpandev; Shetty, Raman; Rajkumar, C; Bantwal, Ganapathi

    2014-01-01

    Aim: To determine the safety and efficacy of biphasic insulin aspart 30 (BIAsp 30) therapy in the Indian patients with type 2 diabetes previously on basal or basal-bolus insulin therapies. Materials and Methods: Patients switching from insulin glargine, neutral protamine Hagedorn (NPH) insulin, or basal-bolus insulin to BIAsp 30 in the Indian cohort of the A1 chieve study were included. Safety and efficacy of treatment was evaluated over 24 weeks. Results: A total of 422 patients (pre-study basal-bolus insulin, 49; NPH insulin, 157; insulin glargine, 216) switched to BIAsp 30. Pre-study insulin doses were 0.61 ± 0.26 U/kg, 0.34 ± 0.2 U/kg and 0.40 ± 0.21 U/kg and the mean week 24 BIAsp 30 doses were 0.50 ± 0.21 U/kg, 0.35 ± 0.15 U/kg and 0.42 ± 0.16 U/kg in the prior basal-bolus insulin, NPH insulin and insulin glargine groups, respectively. No serious adverse drug reactions, major or nocturnal hypoglycemia were reported. The proportion of patients experiencing overall hypoglycemia was significantly lower from baseline (5.6%) to week 24 (1.0%) in the pre-study insulin-glargine group and appeared to be lower in pre-study NPH insulin and basal-bolus insulin groups. Glycemic control improved significantly from baseline week 24 in the pre-study NPH insulin and insulin-glargine groups (P < 0.001), while it appeared to improve in the pre-study basal-bolus group. Quality of life was positively impacted after 24 weeks in all 3 groups. Conclusion: The switch from basal or basal-bolus insulin to BIAsp 30 was safe, well tolerated and improved the glycemic control in this Indian cohort. PMID:25143902

  15. Insulin Human Inhalation

    Science.gov (United States)

    Insulin inhalation is used in combination with a long-acting insulin to treat type 1 diabetes (condition in which the body does not produce insulin and therefore cannot control the amount of sugar ...

  16. CHRONIC ALCOHOL CONSUMPTION HAS BIPHASIC EFFECTS ON HEPATIC INSULIN SIGNALING DEPENDENT ON DOSE

    Science.gov (United States)

    Epidemiological studies have shown paradoxical biphasic effects of alcohol on health. Moderate drinkers have lower overall mortality than teetotalers or than heavy drinkers. There are protective effects of low levels of alcohol consumption (less than one drink day) on diabetes risk and other chroni...

  17. Initiating or Switching to Biphasic Insulin Aspart 30/70 Therapy in Subjects with Type 2 Diabetes Mellitus. An Observational Study

    DEFF Research Database (Denmark)

    Breum, Leif; Almdal, Thomas; Eiken, Pia;

    2008-01-01

    OBJECTIVE: To investigate tolerability and glycemic control over 26 weeks in patients with type 2 diabetes (T2D) who initiated insulin with, or switched to, biphasic insulin aspart 30/70 (BIAsp 30) in routine clinical care. METHODS: This was a non-randomized, non-interventional, open-label, obser......OBJECTIVE: To investigate tolerability and glycemic control over 26 weeks in patients with type 2 diabetes (T2D) who initiated insulin with, or switched to, biphasic insulin aspart 30/70 (BIAsp 30) in routine clinical care. METHODS: This was a non-randomized, non-interventional, open...... adverse drug reactions (SADR), glycemic parameters and hypoglycemic events were obtained from patients' notes, patients' diaries and recall, and transferred to case report forms by physicians at baseline (during 4 weeks prior to BIAsp 30 therapy) and after 12 and 26 weeks of treatment. RESULTS: 421...

  18. L-cysteine reversibly inhibits glucose-induced biphasic insulin secretion and ATP production by inactivating PKM2.

    Science.gov (United States)

    Nakatsu, Daiki; Horiuchi, Yuta; Kano, Fumi; Noguchi, Yoshiyuki; Sugawara, Taichi; Takamoto, Iseki; Kubota, Naoto; Kadowaki, Takashi; Murata, Masayuki

    2015-03-10

    Increase in the concentration of plasma L-cysteine is closely associated with defective insulin secretion from pancreatic β-cells, which results in type 2 diabetes (T2D). In this study, we investigated the effects of prolonged L-cysteine treatment on glucose-stimulated insulin secretion (GSIS) from mouse insulinoma 6 (MIN6) cells and from mouse pancreatic islets, and found that the treatment reversibly inhibited glucose-induced ATP production and resulting GSIS without affecting proinsulin and insulin synthesis. Comprehensive metabolic analyses using capillary electrophoresis time-of-flight mass spectrometry showed that prolonged L-cysteine treatment decreased the levels of pyruvate and its downstream metabolites. In addition, methyl pyruvate, a membrane-permeable form of pyruvate, rescued L-cysteine-induced inhibition of GSIS. Based on these results, we found that both in vitro and in MIN6 cells, L-cysteine specifically inhibited the activity of pyruvate kinase muscle isoform 2 (PKM2), an isoform of pyruvate kinases that catalyze the conversion of phosphoenolpyruvate to pyruvate. L-cysteine also induced PKM2 subunit dissociation (tetramers to dimers/monomers) in cells, which resulted in impaired glucose-induced ATP production for GSIS. DASA-10 (NCGC00181061, a substituted N,N'-diarylsulfonamide), a specific activator for PKM2, restored the tetramer formation and the activity of PKM2, glucose-induced ATP production, and biphasic insulin secretion in L-cysteine-treated cells. Collectively, our results demonstrate that impaired insulin secretion due to exposure to L-cysteine resulted from its direct binding and inactivation of PKM2 and suggest that PKM2 is a potential therapeutic target for T2D.

  19. Controlled and reversible induction of differentiation and activation of adult human hepatocytes by a biphasic culture technique

    Institute of Scientific and Technical Information of China (English)

    Marcus K.H. Auth; Wolf-Otto Bechstein; Roman A. Blaheta; Kim A. Boost; Kerstin Leckel; Wolf-Dietrich Beecken; Tobias Engl; Dietger Jonas; Elsie Oppermann; Philip Hilgard; Bernd H. Markus

    2005-01-01

    AIM: Clinical application of human hepatocytes (HC) is hampered by the progressive loss of growth and differentiation in vitro. The object of the study was to evaluate the effect of a biphasic culture technique on expression and activation of growth factor receptors and differentiation of human adult HC.METHODS: Isolated HC were sequentially cultured in a hormone enriched differentiation medium (DM) containing nicotinamide, insulin, transferrin, selenium, and dexamethasone or activation medium (AM) containing hepatocyte growth factor (HGF), epidermal growth factor (EGF), andgranulocyte-macrophage colony-stimulating factor (GMCSF). Expression, distribution and activation of the HC receptors (MET and EGFR) and the pattern of characteristic cytokeratin (CK) filaments were measured by fluorometry, confocal microscopy and Western blotting.RESULTS: In the biphasic culture system, HC underwent repeated cycles of activation (characterized by expression and activation of growth factor receptors) and re-differentiation (illustrated by distribution of typical filaments CK-18 but low or absent expression of CK-19). In AM increased expression of MET and EGFR was associated with receptor translocation into the cytoplasm and induction of atypical CK-19. In DM low expression of MET and EGFR was localized on the cell membrane and CK-19 was reduced. Receptor phosphorylation required embedding of HC in collagen type Ⅰ gel.CONCLUSION: Control and reversible modulation of growth factor receptor activation of mature human HC can be accomplishedin vitro, when defined signals from the extracellular matrix and sequential growth stimuli are provided. The biphasic technique helps overcome dedifferentiation, which occurs during continuous stimulation by means of growth factors.

  20. Thrice-daily biphasic insulin aspart 30 may be another therapeutic option for Chinese patients with type 2 diabetes inadequately controlled with oral antidiabetic agents

    Institute of Scientific and Technical Information of China (English)

    YANG Wen-ying; JI Qiu-he; ZHU Da-long; YANG Jin-kui; CHEN Lu-lu; LIU Zhi-min; YU De-min; YAN Li

    2009-01-01

    In subjects with type 2 diabetes inadequately controlled with oral antidiabetic agents (OADs), insulin therapy is usually started to improve glycaemic control after failure of diet, exercise and OADs.1 Although there is no standard way to introduce insulin treatment, premixed formulations are a popular option. They offer an alternative to basal-bolus therapy and provide basal and prandial coverage with a single injection. Indeed, Koivisto et al2 in 1999 reported that 39% of patients with type 2 diabetes worldwide used premixed insulin as part of their therapeutic regimen. The modem premixed insulins, such as biphasic insulin aspart 30 (BIAsp 30) are most frequently prescribed twice-daily (BID) in clinical Department of Endocrinology, China-Japan Friendship Hospital, Beijing 100029, China (Yang WY)

  1. Cortisol Exerts Bi-Phasic Regulation of Inflammation in Humans

    OpenAIRE

    Yeager, Mark P.; Pioli, Patricia A.; Guyre, Paul M.

    2010-01-01

    Natural and synthetic glucocorticoids (GCs) have been used for decades to suppress inflammation. In this paper, we re-examine the role of the endogenous GC, cortisol, as a primary homeostatic regulator of the human inflammatory response to injury. Our data show that cortisol regulation of innate immunity can be both pro-inflammatory and anti-inflammatory. Using a human model of in vivo cortisol depletion, we first show that baseline (diurnal) cortisol concentrations do not exert an anti-infla...

  2. A simulation study of the reaction of human heart to biphasic electrical shocks

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    Seemann Gunnar

    2004-06-01

    Full Text Available Abstract Background This article presents a study, which examines the effects of biphasic electrical shocks on human ventricular tissue. The effects of this type of shock are not yet fully understood. Animal experiments showed the superiority of biphasic shocks over monophasic ones in defibrillation. A mathematical computer simulation can increase the knowledge of human heart behavior. Methods The research presented in this article was done with different models representing a three-dimensional wedge of ventricular myocardium. The electrophysiology was described with Priebe-Beuckelmann model. The realistic fiber twist, which is specific to human myocardium was included. Planar electrodes were placed at the ends of the longest side of the virtual cardiac wedge, in a bath medium. They were sources of electrical shocks, which varied in magnitude from 0.1 to 5 V. In a second arrangement ring electrodes were placed directly on myocardium for getting a better view on secondary electrical sources. The electrical reaction of the tissue was generated with a bidomain model. Results The reaction of the tissue to the electrical shock was specific to the initial imposed characteristics. Depolarization appeared in the first 5 ms in different locations. A further study of the cardiac tissue behavior revealed, which features influence the response of the considered muscle. It was shown that the time needed by the tissue to be totally depolarized is much shorter when a biphasic shock is applied. Each simulation ended only after complete repolarization was achieved. This created the possibility of gathering information from all states corresponding to one cycle of the cardiac rhythm. Conclusions The differences between the reaction of the homogeneous tissue and a tissue, which contains cleavage planes, reveals important aspects of superiority of biphasic pulses. ...

  3. Rapamycin has a biphasic effect on insulin sensitivity in C2C12 myotubes due to sequential disruption of mTORC1 and mTORC2

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    Lan eYe

    2012-09-01

    Full Text Available Rapamycin, an inhibitor of mTOR complex 1 (mTORC1, improves insulin sensitivity in acute studies in vitro and in vivo by disrupting a negative feedback loop mediated by S6 kinase. We find that rapamycin has a clear biphasic effect on insulin sensitivity in C2C12 myotubes, with enhanced responsiveness during the first hour that declines to almost complete insulin resistance by 24-48 hours. We and others have recently observed that chronic rapamycin treatment induces insulin resistance in rodents, at least in part due to disruption of mTORC2, an mTOR-containing complex that is not acutely sensitive to the drug. Chronic rapamycin treatment may also impair insulin action via the inhibition of mTORC1-dependent mitochondrial biogenesis and activity, which could result in a buildup of lipid intermediates that are known to trigger insulin resistance. We confirmed that rapamycin inhibits expression of PGC-1α, a key mitochondrial transcription factor, and acutely reduces respiration rate in myotubes. However, rapamycin did not stimulate phosphorylation of PKCθ, a central mediator of lipid-induced insulin resistance. Instead, we found dramatic disruption of mTORC2, which coincided with the onset of insulin resistance. Selective inhibition of mTORC1 or mTORC2 by shRNA-mediated knockdown of specific components (Raptor and Rictor, respectively confirmed that mitochondrial effects of rapamycin are mTORC1-dependent, whereas insulin resistance was recapitulated only by knockdown of mTORC2. Thus, mTORC2 disruption, rather than inhibition of mitochondria, causes insulin resistance in rapamycin-treated myotubes, and this system may serve as a useful model to understand the effects of rapamycin on mTOR signaling in vivo.

  4. Time-dependent biphasic modulation of human BDNF by antidepressants in neuroblastoma cells

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    Musazzi Laura

    2008-07-01

    Full Text Available Abstract Background Recent rodent studies reported that antidepressant treatments affect the expression of brain-derived neurotrophic factor (BDNF mRNA in a way that is dependent on treatment duration, by selective modulation of different BDNF transcripts. However, no data are available for the human BDNF gene. We studied the effect of different antidepressants on BDNF mRNA expression in human neuroblastoma SH-SY5Y cells. Results Cultured cells were treated with the antidepressants fluoxetine, reboxetine and desipramine for different time lengths (6, 24, 48 hours. Expression of total BDNF mRNA was analyzed by reverse transcription PCR and levels of different BDNF transcripts were detected by hemi-nested PCR with specific primers. Short-term treatment (6 hours with reboxetine or desipramine reduced total BDNF, whereas long-term treatment (48 hours significantly increased total BDNF mRNA levels. These changes were accounted for by differential regulation of BDNF IV and VIa/b transcripts. Fluoxetine showed no significant effects. Conclusion This is the first study showing biphasic changes in the expression of total and specific BDNF transcripts in human cells following antidepressant treatments. These findings suggest that biphasic induction of BDNF by antidepressants could be a feature common to rodents and humans and encourage the use of SH-SY5Y cells as a tool for investigation of drug effects on human genes.

  5. CHEMICAL DERIVATION OF HUMAN INSULIN SUPERAGONISM

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The role of three highly conserved insulin residues TyrB26 was studied to better understand the relationship between insulin and receptor from rat adipose tissue plasma membranes. Insulin analogues with a single amino acid substitution or single N-methylation of the peptide bond in the position B26 were all shortened in the C-terminus of the B-chain by four amino acids. The effect of modifications was followed by the binding to the insulin receptor. From our results, we can deduce several conclusions: (1) the replacement of tyrosine in the position B26 by histidine, [N-MeHisB26]-des-tetrapeptide-(B27~B30)-insulin-B26-amide and [N-MeGluB26]-des-tetrapeptide- (B27~B30)-insulin-B26-amide, have no significant effect on the binding affinity and they show binding affinity 105%, 190% and 208%, respectively, of that of human insulin; (2) [AadB26] -des-tetrapeptide-(B27~B30)-insulin-B26-amide and [Phe(4-carboxyB26)]-des-tetrapeptide- (B27~B30)-insulin-B26-amide affect the potency highly positively in vitro studies; they show binding affinity 529 and 289 %, respectively, of that of human insulin.

  6. CHEMICAL DERIVATION OF HUMAN INSULIN SUPERAGONISM

    Institute of Scientific and Technical Information of China (English)

    MA Baoquan; KANG Wei; YAN Junkai

    2007-01-01

    The role of three highly conserved insulin residues TyrB26 was studied to better understand the relationship between insulin and receptor from rat adipose tissue plasma membranes. Insulin analogues with a single amino acid substitution or single N-methylation of the peptide bond in the position B26 were all shortened in the C-terminus of the B-chain by four amino acids. The effect of modifications was followed by the binding to the insulin receptor. From our results, we can deduce several conclusions: (1) the replacement of tyrosine in the position B26 by histidine,[N-MeHisB26]-des-tetrapeptide-(B27~B30)-insulin-B26-amide and [N-MeGluB26]-des-tetrapeptide(B27~B30)-insulin-B26-amide, have no significant effect on the binding affinity and they show binding affinity 105%, 190% and 208%, respectively, of that of human insulin; (2) [AadB26]-des-tetrapeptide-(B27~B30)-insulin-B26-amide and [Phe(4-carboxyB26)]-des-tetrapeptide(B27~B30)-insulin-B26-amide affect the potency highly positively in vitro studies; they show binding affinity 529 and 289 %, respectively, of that of human insulin.

  7. Initiating therapy or switching to biphasic insulin aspart improves glycaemic control in type 2 diabetes: an Indian experience from the A1chieve study.

    Science.gov (United States)

    Kumar, A; Sharma, S K; Rajput, R; Unnikrishnan, A G

    2013-01-01

    Biphasic insulin aspart 30 (BIAsp 30) has been used in patients for almost a decade; There is a wealth of knowledge from clinical trials to document its efficacy and safety and suggest that BIAsp 30 is an option for initiation and intensification of insulin therapy in patients with type 2 diabetes mellitus (T2DM). The A1chieve was a non-interventional study that explored the safety and effectiveness of initiating or switching to insulin analogues in routine clinical practice in more than 60,000 patients from 28 different countries. In this manuscript, we discuss the findings from the subgroup of the Indian cohort who were treated with BIAsp 30. In a cohort of 15287 who were on BIAsp 30, 12645 (83%) were insulin naive and 2642 (17%) had been on insulin therapy earlier. Glycaemic parameters were high at baseline. Mean (SD) HbA1c was 9.2% (1.3) in the these and was comparable in the insulin naive and insulin experienced groups. After 24 weeks of therapy with BIAsp 30, there were reductions in HbA1c in both the insulin naive group, [-1.8 (1.3)] and insulin experienced group [-1.6 (1.3)]. Fasting plasma glucose (FPG) and postprandial plasma glucose (PPG) levels were also reduced significantly from baseline [-3.4 (2.7) and -4.8 (3.8) mmol/L, respectively, p < 0.05). Overall, hypoglycaemia decreased from 1.33 events/patient years at baseline to 0.19 events/patient years at 24 weeks. There was also an increase in quality of life score as evaluated by EQ-5D questionnaire. Initiating insulin therapy with or switching to BIAsp 30 in patients with poor glycaemic control leads to an improvement in glycaemic profile with no major hypoglycaemia or clinically significant weight gain. Therapy with BIAsp 30 also improves the quality of life in patients with type 2 diabetes.

  8. Palmitic acid but not palmitoleic acid induces insulin resistance in a human endothelial cell line by decreasing SERCA pump expression.

    Science.gov (United States)

    Gustavo Vazquez-Jimenez, J; Chavez-Reyes, Jesus; Romero-Garcia, Tatiana; Zarain-Herzberg, Angel; Valdes-Flores, Jesus; Manuel Galindo-Rosales, J; Rueda, Angelica; Guerrero-Hernandez, Agustin; Olivares-Reyes, J Alberto

    2016-01-01

    Palmitic acid is a negative regulator of insulin activity. At the molecular level, palmitic acid reduces insulin stimulated Akt Ser473 phosphorylation. Interestingly, we have found that incubation with palmitic acid of human umbilical vein endothelial cells induced a biphasic effect, an initial transient elevation followed by a sustained reduction of SERCA pump protein levels. However, palmitic acid produced a sustained inhibition of SERCA pump ATPase activity. Insulin resistance state appeared before there was a significant reduction of SERCA2 expression. The mechanism by which palmitic acid impairs insulin signaling may involve endoplasmic reticulum stress, because this fatty acid induced activation of both PERK, an ER stress marker, and JNK, a kinase associated with insulin resistance. None of these effects were observed by incubating HUVEC-CS cells with palmitoleic acid. Importantly, SERCA2 overexpression decreased the palmitic acid-induced insulin resistance state. All these results suggest that SERCA pump might be the target of palmitic acid to induce the insulin resistance state in a human vascular endothelial cell line. Importantly, these data suggest that HUVEC-CS cells respond to palmitic acid-exposure with a compensatory overexpression of SERCA pump within the first hour, which eventually fades out and insulin resistance prevails.

  9. Step-up therapy with biphasic insulin aspart-70/30--Sapporo 1-2-3 study.

    Science.gov (United States)

    Yoshioka, N; Kurihara, Y; Manda, N; Komori, K; Kato, M; Kijima, H; Wada, N; Yanagisawa, K; Aoki, S; Ono, Y; Koike, T

    2009-07-01

    The effectiveness of BIAsp 30 step-up therapy in achieving glycemic control in Japanese patients with type 2 diabetes mellitus was investigated. Study subjects were 99 patients with type 2 diabetes mellitus aged over 20 years who were judged to require insulin therapy due to poor glucose control (HbA1c level of > or =7.5%). BIAsp 30 dosage was determined by the patient's attending physician; coadministration of hypotensive agents and antilipemic agents was permitted, but OAD coadministration was limited to patients already receiving such drugs at the start of the study. Patients who did not achieve HbA1c <6.5% after 16+/-5 weeks with QD (Phase 1) were stepped up to BID (Phase 2). If patients still had not achieved HbA1c <6.5% after 16+/-5 weeks with BID, they were stepped up to TID (Phase 3). 55 of the 99 enrolled subjects completed the study and the rates of achievement of HbA1c <6.5% and HbA1c <7.0% were 45.5% and 74.5%, respectively. Of all registered subjects, 5.1% (5/99) achieved HbA1c <6.5% in QD, 19.5% (16/82) in BID, and 20.6% (7/34) in TID. Statistically significant reductions in HbA1c levels were recorded at the conclusion of each phase, with no incidents requiring intervention, indicating that BIAsp 30 step-up therapy is a safe, simple therapy that can be useful in achieving better glycemic control for Japanese patients with type 2 diabetes mellitus.

  10. Human Insulin from Recombinant DNA Technology

    Science.gov (United States)

    Johnson, Irving S.

    1983-02-01

    Human insulin produced by recombinant DNA technology is the first commercial health care product derived from this technology. Work on this product was initiated before there were federal guidelines for large-scale recombinant DNA work or commercial development of recombinant DNA products. The steps taken to facilitate acceptance of large-scale work and proof of the identity and safety of such a product are described. While basic studies in recombinant DNA technology will continue to have a profound impact on research in the life sciences, commercial applications may well be controlled by economic conditions and the availability of investment capital.

  11. Intracellular insulin in human tumors: examples and implications

    Directory of Open Access Journals (Sweden)

    Radulescu Razvan T

    2011-04-01

    Full Text Available Abstract Insulin is one of the major metabolic hormones regulating glucose homeostasis in the organism and a key growth factor for normal and neoplastic cells. Work conducted primarily over the past 3 decades has unravelled the presence of insulin in human breast cancer tissues and, more recently, in human non-small cell lung carcinomas (NSCLC. These findings have suggested that intracellular insulin is involved in the development of these highly prevalent human tumors. A potential mechanism for such involvement is insulin's binding and inactivation of the retinoblastoma tumor suppressor protein (RB which in turn is likely controlled by insulin-degrading enzyme (IDE. This model and its supporting data are collectively covered in this survey in order to provide further insight into insulin-driven oncogenesis and its reversal through future anticancer therapeutics.

  12. Human gut microbes impact host serum metabolome and insulin sensitivity

    DEFF Research Database (Denmark)

    Pedersen, Helle Krogh; Gudmundsdottir, Valborg; Nielsen, Henrik Bjørn

    2016-01-01

    Insulin resistance is a forerunner state of ischaemic cardiovascular disease and type 2 diabetes. Here we show how the human gut microbiome impacts the serum metabolome and associates with insulin resistance in 277 non-diabetic Danish individuals. The serum metabolome of insulin-resistant individ......Insulin resistance is a forerunner state of ischaemic cardiovascular disease and type 2 diabetes. Here we show how the human gut microbiome impacts the serum metabolome and associates with insulin resistance in 277 non-diabetic Danish individuals. The serum metabolome of insulin......-resistant individuals is characterized by increased levels of branched-chain amino acids (BCAAs), which correlate with a gut microbiome that has an enriched biosynthetic potential for BCAAs and is deprived of genes encoding bacterial inward transporters for these amino acids. Prevotella copri and Bacteroides vulgatus...

  13. Differences in bioactivity between human insulin and insulin analogues approved for therapeutic use- compilation of reports from the past 20 years

    OpenAIRE

    Werner Haim; Chantelau Ernst A

    2011-01-01

    Abstract In order to provide comprehensive information on the differences in bioactivity between human insulin and insulin analogues, published in vitro comparisons of human insulin and the rapid acting analogues insulin lispro (Humalog®), insulin aspart ( NovoRapid®), insulin glulisine (Apidra®), and the slow acting analogues insulin glargine (Lantus®), and insulin detemir (Levemir®) were gathered from the past 20 years (except for receptor binding studies). A total of 50 reports were retrie...

  14. Effects of biphasic, basal-bolus or basal insulin analogue treatments on carotid intima-media thickness in patients with type 2 diabetes mellitus

    DEFF Research Database (Denmark)

    Lundby-Christensen, Louise; Vaag, Allan; Tarnow, Lise;

    2016-01-01

    in combination with insulin detemir once daily (n=138) versus insulin detemir alone once daily (n=137), aiming at HbA1c≤7.0% (≤53 mmol/mol). OUTCOMES: Primary outcome was change in mean carotid IMT (a marker of subclinical cardiovascular disease). HbA1c, insulin dose, weight, and hypoglycaemic and serious...

  15. Interacting with the Human Insulin Receptor

    DEFF Research Database (Denmark)

    Kidmose, Rune Thomas; Andersen, Gregers Rom

    2016-01-01

    Insulin is an essential regulator of glucose homeostasis. In this issue of Structure, Croll et al. (2016) reports a significantly improved model of the Fab-complexed IR ectodomain refined against a dataset extending to 3.3 Å.......Insulin is an essential regulator of glucose homeostasis. In this issue of Structure, Croll et al. (2016) reports a significantly improved model of the Fab-complexed IR ectodomain refined against a dataset extending to 3.3 Å....

  16. Effect of exercise on insulin action in human skeletal muscle

    DEFF Research Database (Denmark)

    Richter, Erik; Mikines, K J; Galbo, Henrik

    1989-01-01

    The effect of 1 h of dynamic one-legged exercise on insulin action in human muscle was studied in 6 healthy young men. Four hours after one-legged knee extensions, a three-step sequential euglycemic hyperinsulinemic clamp combined with arterial and bilateral femoral vein catheterization was perfo...... recovery of human skeletal muscle.......The effect of 1 h of dynamic one-legged exercise on insulin action in human muscle was studied in 6 healthy young men. Four hours after one-legged knee extensions, a three-step sequential euglycemic hyperinsulinemic clamp combined with arterial and bilateral femoral vein catheterization...... consumption and at some insulin concentrations on potassium exchange. In contrast, no change in insulin effects on limb exchange of free fatty acids, glycerol, alanine or tyrosine were found after exercise. Glycogen concentration in rested vastus lateralis muscle did not increase measurably during the clamp...

  17. Eccentric exercise decreases maximal insulin action in humans

    DEFF Research Database (Denmark)

    Asp, Svend; Daugaard, J R; Kristiansen, S

    1996-01-01

    1. Unaccustomed eccentric exercise decreases whole-body insulin action in humans. To study the effects of one-legged eccentric exercise on insulin action in muscle and systemically, the euglycaemic clamp technique combined with arterial and bilateral femoral venous catheterization was used. Seven...... subjects participated in two euglycaemic clamps, performed in random order. One clamp was preceded 2 days earlier by one-legged eccentric exercise (post-eccentric exercise clamp (PEC)) and one was without the prior exercise (control clamp (CC)). 2. During PEC the maximal insulin-stimulated glucose uptake......) necessary to maintain euglycaemia during maximal insulin stimulation was lower during PEC compared with CC (15.7%, 81.3 +/- 3.2 vs. 96.4 +/- 8.8 mumol kg-1 min-1, P eccentric exercise, muscle and whole-body insulin action is impaired at maximal...

  18. A secretory function of human insulin-producing cellsin vivo

    Institute of Scientific and Technical Information of China (English)

    Yan-Hua Hu; De-Quan Wu; Feng Gao; Guo-Dong Li; Lei Yao; Xin-Chen Zhang

    2009-01-01

    BACKGROUND: Mesenchymal stem cells derived from human umbilical cord blood (UCB-MSCs) have good research and application prospects in the treatment of diabetes. We once induced UCB-MSCs to differentiate into insulin-producing cells (IPCs)in vitro, but we did not know the functions of these cellsin vivo. The aim of this study was to assess the functional effects of IPCs on insulin secretion and their role in the treatment of diabetesin vivo. METHODS: UCB-MSCs were induced to IPCs by an inducing protocol with extracellular matrix gel. BALB/C nude mice were made hyperglycemic by intraperitoneal injection of streptozotocin. The diabetic mice were transplanted with 1×107 IPCs under the renal capsule or with phosphate-buffered saline as a control. After transplantation, the grafts were analyzed by immunocytochemistry for the expression of human insulin; the serum human insulin levels were measured; and blood glucose and body weight status were monitored. RESULTS: Immunolfuorescence showed that numerous IPCs under the kidney capsule were insulin-positive. On day 14 after transplantation, the serum human insulin level of the treatment group (n=9) averaged 0.44±0.12 mU/L, which was higher than that of the control group (n=9) that did not express insulin (t=10.842,P<0.05). The diabetic mice remained hyperglycemic and kept losing body weight after IPC transplantation, and there was no signiifcant difference in the control group. CONCLUSION: IPCs differentiated from UCB-MSCs generate human insulin in diabetic mice, but more research is needed to make further use of them to regulate hyperglycemia and body weightin vivo.

  19. Bovine and human insulin adsorption at lipid monolayers: a comparison

    Directory of Open Access Journals (Sweden)

    Sergio eMauri

    2015-07-01

    Full Text Available Insulin is a widely used peptide in protein research and it is utilised as a model peptide to understand the mechanics of fibril formation, which is believed to be the cause of diseases such as Alzheimer and Creutzfeld-Jakob syndrome. Insulin has been used as a model system due to its biomedical relevance, small size and relatively simple tertiary structure. The adsorption of insu lin on a variety of surfaces has become the focus of numerous studies lately. These works have helped in elucidating the consequence of surface/protein hydrophilic/hydrophobic interaction in terms of protein refolding and aggregation. Unfortunately, such model surfaces differ significantly from physiological surfaces. Here we spectroscopically investigate the adsorption of insulin at lipid monolayers, to further our understanding of the interaction of insulin with biological surfaces.In particular we study the effect of minor mutations of insulin’s primary amino acid sequence on its interaction with 1,2-Dipalmitoyl-sn-glycero-3-phosphoglycerol (DPPG model lipid layers. We probe the structure of bovine and human insulin at the lipid/water interface using sum frequency generation spectroscopy (SFG. The SFG experiments are complemented with XPS analysis of Langmuir-Schaefer deposited lipid/insulin films. We find that bovine and human insulin, even though very similar in sequence, show a substantially different behavior when interacting with lipid films.

  20. Acute pain induces insulin resistance in humans

    DEFF Research Database (Denmark)

    Greisen, J.; Juhl, C.B.; Grøfte, Thorbjørn

    2001-01-01

    Background: Painful trauma results in a disturbed metabolic state with impaired insulin sensitivity, which is related to the magnitude of the trauma. The authors explored whether pain per se influences hepatic and extrahepatic actions of insulin. Methods: Ten healthy male volunteers underwent two...... randomly sequenced hyperinsulinemic–euglycemic (insulin infusion rate, 0.6 mU · kg-1 · min-1 for 180 min) clamp studies 4 weeks apart. Self-controlled painful electrical stimulation was applied to the abdominal skin for 30 min, to a pain intensity of 8 on a visual analog scale of 0–10, just before...... the clamp procedure (study P). In the other study, no pain was inflicted (study C). Results: Pain reduced whole-body insulin-stimulated glucose uptake from 6.37 ± 1.87 mg · kg-1 · min-1 (mean ± SD) in study C to 4.97 ± 1.38 mg · kg-1 · min-1 in study P (P

  1. Influence of PAMAM dendrimers on the human insulin

    Science.gov (United States)

    Nowacka, Olga; Miłowska, Katarzyna; Ionov, Maksim; Bryszewska, Maria

    2015-12-01

    Dendrimers are specific class of polymeric macromolecules with wide spectrum of properties. One of the promising activities of dendrimers involves inhibition of protein fibril formation. Aggregation and fibrillation of insulin occurs in insulin-dependent diabetic patients after repeated administration, due to these processes being very easily triggered by the conditions of drug administration. The aim of this work was to study the influence of various generations PAMAM dendrimers on human insulin zeta potential, secondary structure and dithiotreitol (DTT)-induced aggregation. We observed the dependence between the number of positive charges on the surface of the PAMAM dendrimer and the values of zeta potential. Addition of dendrimers to insulin caused insignificant changes in the secondary structure. There was a small decrease in ellipticity, but it did not result in alterations in the circular dichroism (CD) spectrum shape. Dendrimers neither induced protein aggregation nor inhibited the aggregation process induced by DTT, except for 0.01 µmol/l concentration.

  2. Prevalence of lipodystrophy associated with human recombinant insulin

    Directory of Open Access Journals (Sweden)

    S. Akbarzadeh

    2008-01-01

    Full Text Available AbstractBackground and Purpose: Lipodystrophy is potentially a clinical adverse effect, associated with insulin therapy and is believed that usage of human recombinant insulin’s is associated with decreasing prevalence of Lipodystrophy. The objective of this study was to determine the prevalence of insulin induced Lipodystrophy, among diabetic out-patients referred to Imam Khomeini Hospital, in Sari during 2007.Materials and Methods: In this cross sectional descriptive study, 220 diabetic patients referred to the Diabetes Center at Imam Khomeini Hospital, in Sari, who under treatment by insulin at least three months prior to referral was evaluated.First, the demographic and clinical characteristics of the patients were recorded in a questionnaire; then all patients were examined clinically to evaluate lipodystrophy. In all subjects, glycated hemoglobin (HbA1C was measured to assess the range of blood glucose level control. Recorded data were analyzed by statistical methods, such as descriptive T-test and X².Results: Of 220 diabetic patients studied, thirty-five (15.9% showed clinical evidences of insulin induced Lipodystrophy; 32 out of 35 cases of Lipodystrophic patients (14.5% had Lipohypertrophy, while 3 cases (1.4% had Lipoatrophy.The factors included Age, Sex, Education, BMI (Body mass index, type of Diabetes, The duration of insulin consumption and injection site had statistically significant effects on development of insulin induced Lipodystrophy (P<0.05.Conclusion: The results of this study demonstrated that despite using human recombinant insulin’s, the prevalence of insulin induced lipodystrophy, especially Lipohypertrophy, has remained high up to present. Therefore, regular examination of patients for this side effect is necessary, especially in subjects without good control of blood glucose level.Prevalence of lipodystrophy associated with human recombinant insulinZ. Kashi, M.D. + Z. Hajheydari, M.D.* O. Akha, M.D. * S

  3. Insulin analogues versus human insulin in type 1 diabetes: direct and indirect meta-analyses of efficacy and safety

    Directory of Open Access Journals (Sweden)

    Andréia Cristina Conegero Sanches

    2013-09-01

    Full Text Available All patients with Diabetes Mellitus (DM receive insulin therapy. In this study, we evaluated the efficacy, safety and tolerability of human insulin and insulin analogues. We performed a systematic review of the literature and a meta-analysis according to the Cochrane Collaboration methodology. In the absence of clinical studies comparing insulins, we performed a mixed treatment comparison to establish the differences between the active treatments. We included studies published from 1995 to 2010. HbA1c results, episodes of hypoglycemia and nocturnal hypoglycemia data were extracted and analyzed. Thirty-five randomized clinical trials were selected after examining the abstract and a full text review. These studies included 4,206 patients who received long-acting insulin analogues and 5,733 patients who received short-acting insulin analogues. Pooled data regarding efficacy indicated no significant differences in HbA1c values between glargine or detemir (once daily and NPH insulin. However, a twice-daily dose of detemir produced differences in HbA1c values that favored detemir (-0.14% [95% CI: -0.21 to -0.08]; p<0.0001; I²=0%. Direct and indirect comparisons are consistent and show that there were no significant differences between human insulin and insulin analogues in efficacy or safety. Our results indicate that long- and short-acting insulin analogues offer few clinical advantages over conventional human insulin.

  4. Interleukin-1β inhibits insulin signaling and prevents insulin-stimulated system A amino acid transport in primary human trophoblasts.

    Science.gov (United States)

    Aye, Irving L M H; Jansson, Thomas; Powell, Theresa L

    2013-12-05

    Interleukin-1β (IL-1β) promotes insulin resistance in tissues such as liver and skeletal muscle; however the influence of IL-1β on placental insulin signaling is unknown. We recently reported increased IL-1β protein expression in placentas of obese mothers, which could contribute to insulin resistance. In this study, we tested the hypothesis that IL-1β inhibits insulin signaling and prevents insulin-stimulated amino acid transport in cultured primary human trophoblast (PHT) cells. Cultured trophoblasts isolated from term placentas were treated with physiological concentrations of IL-1β (10pg/ml) for 24h. IL-1β increased the phosphorylation of insulin receptor substrate-1 (IRS-1) at Ser307 (inhibitory) and decreased total IRS-1 protein abundance but did not affect insulin receptor β expression. Furthermore, IL-1β inhibited insulin-stimulated phosphorylation of IRS-1 (Tyr612, activation site) and Akt (Thr308) and prevented insulin-stimulated increase in PI3K/p85 and Grb2 protein expression. IL-1β alone stimulated cRaf (Ser338), MEK (Ser221) and Erk1/2 (Thr202/Tyr204) phosphorylation. The inflammatory pathways nuclear factor kappa B and c-Jun N-terminal kinase, which are involved in insulin resistance, were also activated by IL-1β treatment. Moreover, IL-1β inhibited insulin-stimulated System A, but not System L amino acid uptake, indicating functional impairment of insulin signaling. In conclusion, IL-1β inhibited the insulin signaling pathway by inhibiting IRS-1 signaling and prevented insulin-stimulated System A transport, thereby promoting insulin resistance in cultured PHT cells. These findings indicate that conditions which lead to increased systemic maternal or placental IL-1β levels may attenuate the effects of maternal insulin on placental function and consequently fetal growth.

  5. Effects of tacrolimus (FK506) on human insulin gene expression, insulin mRNA levels, and insulin secretion in HIT-T15 cells.

    OpenAIRE

    1996-01-01

    FK506 (tacrolimus) is an immunosuppressive drug which interrupts Ca2+-calmodulin-calcineurin signaling pathways in T lymphocytes, thereby blocking antigen activation of T cell early activation genes. Regulation of insulin gene expression in the beta cell may also involve Ca2+-signaling pathways and FK506 has been associated with insulin-requiring diabetes mellitus during clinical use. The purpose of this study was to characterize the effects of FK506 on human insulin gene transcription, insul...

  6. Secretory expression of α single-chain insulin precursor in yeast and its conversion into human insulin

    Institute of Scientific and Technical Information of China (English)

    张友尚; 胡红明; 蔡若蓉; 冯佑民; 朱尚权; 贺潜斌; 唐月华; 徐明华; 许英镐; 张新堂; 刘滨; 梁镇和

    1996-01-01

    A synthetic single-chain porcine insulin precursor (PIP) gene and an α-mating factor leader sequence (αMFL) gene obtained by the PCR method are inserted between the promoter and 3’-terminating sequence of the alcohol dehydrogenase gene ADH1 in plasmid pVT102-U to form plasmid pVT102-U/α MFL-PIP. The single-chain insulin precursor is expressed and secreted to the culture medium by Saccharomyces cererisiae transformed by pVT102-U/αMFL-PIP. The precursor is purified and converted into human insulin by tryptic transpeptidation. The purified human insulin is fully active and can be crystallized. The overall yield of human insulin is 25 mg per liter of culture medium.

  7. Calcineurin inhibitors acutely improve insulin sensitivity without affecting insulin secretion in healthy human volunteers

    DEFF Research Database (Denmark)

    Øzbay, Aygen; Møller, Niels; Juhl, Claus;

    2012-01-01

    and tacrolimus has been attributed to both beta cell dysfunction and impaired insulin sensitivity. WHAT THIS STUDY ADDS: This is the first trial to investigate beta cell function and insulin sensitivity using gold standard methodology in healthy human volunteers treated with clinically relevant doses...... of NODAT remains unclear. We sought to compare the impact of CsA and Tac on glucose metabolism in human subjects. METHODS: Ten healthy men underwent 5 h infusions of CsA, Tac and saline in a randomized, double-blind, crossover study. During infusion glucose metabolism was investigated using following...... observed in circulating glucagon, FFA or adiponectin concentrations. Mean blood concentrations of CNIs were 486.9 ± 23.5 µg l(-1) for CsA and 12.8 ± 0.5 µg l(-1) for Tac. CONCLUSIONS: Acute effects of i.v. CsA, and to a lesser degree Tac infusions, in healthy volunteers include increased insulin...

  8. Bimodal effect on pancreatic β-cells of secretory products from normal or insulin-resistant human skeletal muscle

    DEFF Research Database (Denmark)

    Bouzakri, Karim; Plomgaard, Peter; Berney, Thierry;

    2011-01-01

    Type 2 diabetes is characterized by insulin resistance with a relative deficiency in insulin secretion. This study explored the potential communication between insulin-resistant human skeletal muscle and primary (human and rat) ß-cells.......Type 2 diabetes is characterized by insulin resistance with a relative deficiency in insulin secretion. This study explored the potential communication between insulin-resistant human skeletal muscle and primary (human and rat) ß-cells....

  9. Bimodal effect on pancreatic β-cells of secretory products from normal or insulin-resistant human skeletal muscle

    DEFF Research Database (Denmark)

    Bouzakri, Karim; Plomgaard, Peter; Berney, Thierry;

    2011-01-01

    Type 2 diabetes is characterized by insulin resistance with a relative deficiency in insulin secretion. This study explored the potential communication between insulin-resistant human skeletal muscle and primary (human and rat) β-cells.......Type 2 diabetes is characterized by insulin resistance with a relative deficiency in insulin secretion. This study explored the potential communication between insulin-resistant human skeletal muscle and primary (human and rat) β-cells....

  10. Expression profiling of insulin action in human myotubes

    DEFF Research Database (Denmark)

    Hansen, Lars; Gaster, Michael; Oakeley, Edward J

    2004-01-01

    ), 0.5, 1, 2, 4, 8, and 24 h, mRNA contents were analyzed in human myotubes for each time point using Affymetrix DNA chip technology. Insulin treatment induced an inflammatory and pro-angiogenic response in the myotubes, with expression of early response factors followed by inflammatory chemokines......, metabolic enzymes, and finally cell cycle regulating genes. One-hundred-forty-four genes were differentially expressed in myotubes from donors with type 2 diabetes compared with control subjects, including HSP70, apolipoprotein D/E, tropomyosin, myosin, and actin previously reported from in vivo studies...... of diabetic skeletal muscle. We conclude, (i) that insulin induces a time-dependent inflammatory and pro-angiogenic transcriptional response in cultured human myotubes, (ii) that myotubes in vitro retain a gene expression pattern specific for type 2 diabetes and sharing five genes with that of type 2 diabetic...

  11. Studies on the mechanism of insulin resistance in the liver from humans with noninsulin-dependent diabetes. Insulin action and binding in isolated hepatocytes, insulin receptor structure, and kinase activity.

    OpenAIRE

    Caro, J F; Ittoop, O; Pories, W J; Meelheim, D; Flickinger, E G; Thomas, F; Jenquin, M; Silverman, J F; Khazanie, P G; Sinha, M. K.

    1986-01-01

    We have developed a method to isolate insulin-responsive human hepatocytes from an intraoperative liver biopsy to study insulin action and resistance in man. Hepatocytes from obese patients with noninsulin-dependent diabetes were resistant to maximal insulin concentration, and those from obese controls to submaximal insulin concentration in comparison to nonobese controls. Insulin binding per cell number was similar in all groups. However, insulin binding per surface area was decreased in the...

  12. Differences in bioactivity between human insulin and insulin analogues approved for therapeutic use- compilation of reports from the past 20 years

    Directory of Open Access Journals (Sweden)

    Werner Haim

    2011-06-01

    Full Text Available Abstract In order to provide comprehensive information on the differences in bioactivity between human insulin and insulin analogues, published in vitro comparisons of human insulin and the rapid acting analogues insulin lispro (Humalog®, insulin aspart ( NovoRapid®, insulin glulisine (Apidra®, and the slow acting analogues insulin glargine (Lantus®, and insulin detemir (Levemir® were gathered from the past 20 years (except for receptor binding studies. A total of 50 reports were retrieved, with great heterogeneity among study methodology. However, various differences in bioactivity compared to human insulin were obvious (e.g. differences in effects on metabolism, mitogenesis, apoptosis, intracellular signalling, thrombocyte function, protein degradation. Whether or not these differences have clinical bearings (and among which patient populations remains to be determined.

  13. Differences in bioactivity between human insulin and insulin analogues approved for therapeutic use- compilation of reports from the past 20 years.

    Science.gov (United States)

    Werner, Haim; Chantelau, Ernst A

    2011-01-01

    In order to provide comprehensive information on the differences in bioactivity between human insulin and insulin analogues, published in vitro comparisons of human insulin and the rapid acting analogues insulin lispro (Humalog®), insulin aspart ( NovoRapid®), insulin glulisine (Apidra®), and the slow acting analogues insulin glargine (Lantus®), and insulin detemir (Levemir®) were gathered from the past 20 years (except for receptor binding studies). A total of 50 reports were retrieved, with great heterogeneity among study methodology. However, various differences in bioactivity compared to human insulin were obvious (e.g. differences in effects on metabolism, mitogenesis, apoptosis, intracellular signalling, thrombocyte function, protein degradation). Whether or not these differences have clinical bearings (and among which patient populations) remains to be determined.

  14. Ingested human insulin inhibits the mosquito NF-¿B-dependent immune response to Plasmodium falciparum

    Science.gov (United States)

    We showed previously that ingested human insulin activates the insulin/IGF-1 signaling pathway in Anopheles stephensi and increases the susceptibility of these mosquitoes to Plasmodium falciparum. In other organisms insulin can alter immune responsiveness through regulation of NF-kB transcription fa...

  15. Effects of insulin detemir and NPH insulin on body weight and appetite-regulating brain regions in human type 1 diabetes: a randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Larissa W van Golen

    Full Text Available Studies in rodents have demonstrated that insulin in the central nervous system induces satiety. In humans, these effects are less well established. Insulin detemir is a basal insulin analog that causes less weight gain than other basal insulin formulations, including the current standard intermediate-long acting Neutral Protamine Hagedorn (NPH insulin. Due to its structural modifications, which render the molecule more lipophilic, it was proposed that insulin detemir enters the brain more readily than other insulins. The aim of this study was to investigate whether insulin detemir treatment differentially modifies brain activation in response to food stimuli as compared to NPH insulin. In addition, cerebral spinal fluid (CSF insulin levels were measured after both treatments. Brain responses to viewing food and non-food pictures were measured using functional Magnetic Resonance Imaging in 32 type 1 diabetic patients, after each of two 12-week treatment periods with insulin detemir and NPH insulin, respectively, both combined with prandial insulin aspart. CSF insulin levels were determined in a subgroup. Insulin detemir decreased body weight by 0.8 kg and NPH insulin increased weight by 0.5 kg (p = 0.02 for difference, while both treatments resulted in similar glycemic control. After treatment with insulin detemir, as compared to NPH insulin, brain activation was significantly lower in bilateral insula in response to visual food stimuli, compared to NPH (p = 0.02 for right and p = 0.05 for left insula. Also, CSF insulin levels were higher compared to those with NPH insulin treatment (p = 0.003. Our findings support the hypothesis that in type 1 diabetic patients, the weight sparing effect of insulin detemir may be mediated by its enhanced action on the central nervous system, resulting in blunted activation in bilateral insula, an appetite-regulating brain region, in response to food stimuli.ClinicalTrials.gov NCT00626080.

  16. Mecasermin (recombinant human insulin-like growth factor I).

    Science.gov (United States)

    Rosenbloom, Arlan L

    2009-01-01

    Growth hormone (GH) exercises its growth effects by stimulating insulin-like growth factor I (IGF-I) synthesis in the liver (endocrine IGF-I) and by inducing chondrocyte differentiation/replication and local production of IGF-I (paracrine/autocrine IGF-I). Injectable recombinant human (rh)IGF-I (mecasermin) has been available for nearly 20 years for treatment of the rare instances of GH insensitivity caused by GH receptor defects or GH-inhibiting antibodies. Full restoration of normal growth, as occurs with rhGH replacement of GH deficiency, is not seen, presumably because only the endocrine deficiency is addressed. RhIGF-I has also been effective as an insulin-sensitizing agent in severe insulin-resistant conditions. Although the insulin-sensitizing effect may benefit both type 1 and type 2 diabetes, there are no ongoing clinical trials because of concern about risk of retinopathy and other complications. Promotion of rhIGF-I for treatment of idiopathic short stature has been intensive, with neither data nor rationale suggesting that there might be a better response than has been documented with rhGH. Other applications that have either been considered or are undergoing clinical trial are based on the ubiquitous tissue-building properties of IGF-I and include chronic liver disease, cystic fibrosis, wound healing, AIDS muscle wasting, burns, osteoporosis, Crohn's disease, anorexia nervosa, Werner syndrome, X-linked severe combined immunodeficiency, Alzheimer's disease, muscular dystrophy, amyotrophic lateral sclerosis, hearing loss prevention, spinal cord injury, cardiovascular protection, and prevention of retinopathy of prematurity. The most frequent side effect is hypoglycemia, which is readily controlled by administration with meals. Other common adverse effects involve hyperplasia of lymphoid tissue, which may require tonsillectomy/adenoidectomy, accumulation of body fat, and coarsening of facies. The anti-apoptotic properties of IGF-I are implicated in cancer

  17. Preparation and In Vitro and In Vivo Performance of Magnesium Ion Substituted Biphasic Calcium Phosphate Spherical Microscaffolds as Human Adipose Tissue-Derived Mesenchymal Stem Cell Microcarriers

    Directory of Open Access Journals (Sweden)

    Dong-Hyun Kim

    2013-01-01

    Full Text Available Magnesium ion substituted biphasic calcium phosphate (Mg-BCP bioceramic microscaffolds with spherical and porous morphology were successfully prepared using in situ coprecipitation and rotary spray drying atomization process for application of tissue engineering combined with human adipose tissue-derived mesenchymal stem cells (hAT-MSCs. After 4 weeks of immersion in Hanks’ balanced salt solution (HBSS, Mg-BCP micro-scaffolds showed the enhanced biodegradation and bioactivity due to the substituted Mg2+ ion present in the BCP structure. In this study, it was observed that hAT-MSCs have clearly attached on the surface of Mg-BCP micro-scaffolds. In addition, Mg-BCP micro-scaffolds exhibited the improved biocompatibility and osteoconductivity via in vitro and in vivo biological tests with hAT-MSCs. Therefore, these bioceramic micro-scaffolds had potential to be used as hAT-MSCs microcarriers for biomedical applications.

  18. Insulin resistance alters islet morphology in nondiabetic humans

    DEFF Research Database (Denmark)

    Mezza, Teresa; Muscogiuri, Giovanna; Sorice, Gian Pio

    2014-01-01

    Type 2 diabetes is characterized by poor glucose uptake in metabolic tissues and manifests when insulin secretion fails to cope with worsening insulin resistance. In addition to its effects on skeletal muscle, liver, and adipose tissue metabolism, it is evident that insulin resistance also affects...... pancreatic β-cells. To directly examine the alterations that occur in islet morphology as part of an adaptive mechanism to insulin resistance, we evaluated pancreas samples obtained during pancreatoduodenectomy from nondiabetic subjects who were insulin-resistant or insulin-sensitive. We also compared...... insulin sensitivity, insulin secretion, and incretin levels between the two groups. We report an increased islet size and an elevated number of β- and α-cells that resulted in an altered β-cell-to-α-cell area in the insulin- resistant group. Our data in this series of studies suggest that neogenesis from...

  19. Insulin promotes glycogen storage and cell proliferation in primary human astrocytes.

    Directory of Open Access Journals (Sweden)

    Martin Heni

    Full Text Available INTRODUCTION: In the human brain, there are at least as many astrocytes as neurons. Astrocytes are known to modulate neuronal function in several ways. Thus, they may also contribute to cerebral insulin actions. Therefore, we examined whether primary human astrocytes are insulin-responsive and whether their metabolic functions are affected by the hormone. METHODS: Commercially available Normal Human Astrocytes were grown in the recommended medium. Major players in the insulin signaling pathway were detected by real-time RT-PCR and Western blotting. Phosphorylation events were detected by phospho-specific antibodies. Glucose uptake and glycogen synthesis were assessed using radio-labeled glucose. Glycogen content was assessed by histochemistry. Lactate levels were measured enzymatically. Cell proliferation was assessed by WST-1 assay. RESULTS: We detected expression of key proteins for insulin signaling, such as insulin receptor β-subunit, insulin receptor substrat-1, Akt/protein kinase B and glycogen synthase kinase 3, in human astrocytes. Akt was phosphorylated and PI-3 kinase activity increased following insulin stimulation in a dose-dependent manner. Neither increased glucose uptake nor lactate secretion after insulin stimulation could be evidenced in this cell type. However, we found increased insulin-dependent glucose incorporation into glycogen. Furthermore, cell numbers increased dose-dependently upon insulin treatment. DISCUSSION: This study demonstrated that human astrocytes are insulin-responsive at the molecular level. We identified glycogen synthesis and cell proliferation as biological responses of insulin signaling in these brain cells. Hence, this cell type may contribute to the effects of insulin in the human brain.

  20. Transcriptional directionality of the human insulin-degrading enzyme promoter.

    Science.gov (United States)

    Zhang, Lang; Wang, Pan; Ding, Qingyang; Wang, Zhao

    2013-10-01

    Unidirectional promoters dominate among mammalian genomes. However, the mechanism through which the transcriptional directionality of promoters is accomplished remains to be clarified. Insulin-degrading enzyme (IDE) is a ubiquitously expressed zinc metalloprotease, whose promoter contains a CpG island. We previously showed that the basal promoter region of mouse IDE has bidirectional transcriptional activity, but an upstream promoter element blocks its antisense transcription. Therefore, we wonder whether the human IDE promoter contains an analogous element. Similarly, the basal promoter region of human IDE (-102 ~ +173 and -196 ~ +173 relative to the transcription start site) showed bidirectional transcriptional activity. However, the region from -348 to +173 could only be transcribed from the normal orientation, implying that an upstream promoter element between -348 and -196 blocks the antisense transcription of the human IDE promoter. Through promoter deletion and mutagenesis analysis, we mapped this element precisely and found that the upstream promoter element locates between -318 and -304. Furthermore, the transcription-blocking elements in the mouse and human IDE promoters inhibited the transcription of the SV40 promoter when put downstream of it. In conclusion, we identify an upstream promoter element which blocks the antisense transcription of the human IDE promoter. Our studies are helpful to clarify the transcriptional directionality of promoters.

  1. Human insulin dynamics in women: a physiologically based model.

    Science.gov (United States)

    Weiss, Michael; Tura, Andrea; Kautzky-Willer, Alexandra; Pacini, Giovanni; D'Argenio, David Z

    2016-02-01

    Currently available models of insulin dynamics are mostly based on the classical compartmental structure and, thus, their physiological utility is limited. In this work, we describe the development of a physiologically based model and its application to data from 154 patients who underwent an insulin-modified intravenous glucose tolerance test (IM-IVGTT). To determine the time profile of endogenous insulin delivery without using C-peptide data and to evaluate the transcapillary transport of insulin, the hepatosplanchnic, renal, and peripheral beds were incorporated into the circulatory model as separate subsystems. Physiologically reasonable population mean estimates were obtained for all estimated model parameters, including plasma volume, interstitial volume of the peripheral circulation (mainly skeletal muscle), uptake clearance into the interstitial space, hepatic and renal clearance, as well as total insulin delivery into plasma. The results indicate that, at a population level, the proposed physiologically based model provides a useful description of insulin disposition, which allows for the assessment of muscle insulin uptake.

  2. Assessment of intracellular insulin content during all steps of human islet isolation procedure.

    Science.gov (United States)

    Brandhorst, H; Brandhorst, D; Brendel, M D; Hering, B J; Bretzel, R G

    1998-01-01

    This study investigated the recovery of pancreatic insulin content during human islet isolation prior to and after digestion-filtration, continuous Hanks-Ficoll gradient purification (n = 20), and 3-4 day culture at 22 degrees C (n = 6). The native insulin content varied in a wide range from 28.4 U to 360.8 U/pancreas. After digestion the initially measured average insulin content of 115.8 +/- 20.8 U/pancreas (mean +/- SEM) increased to 264.6 +/- 22.8% (p asymetrical distribution of insulin within the pancreas. Sampling of insulin within the pancreatic caput seemed not to be representative for the insulin content of the complete native organ, because the ratio of insulin per gram tissue within the pancreatic cauda compared to the caput (n = 5) was 2.4 +/- 0.4 (p < 0.05). After purification total insulin recovery was 55.3 +/- 4.8% (p < 0.001). Because recovery of islet equivalent number (IEQ) (83.7 +/- 4.4%) exceeded insulin recovery, insulin/IEQ ratio decreased from 656.8 +/- 70.6 microU/IEQ before purification to 436.4 +/- 58.1 microU/IEQ (p < 0.001) after purification. After 22 degrees C culture (n = 6) recovery of insulin and IEQ was 80.1 +/- 8.1% (p < 0.05) and 92.8 +/- 3.5% (p = NS), respectively. Insulin content per IEQ decreased to 85.8 +/- 6.5% (p < 0.05). This study clearly shows that most of islet insulin is lost during purification. This seems to be caused rather by an amplified insulin release than by the loss of islets itself. This release may facilitate the separation of endocrine and exocrine tissue by gradient centrifugation, but may also accelerate islet exhaustion detrimental for long-term insulin independence.

  3. Role of diacylglycerol activation of PKCθ in lipid-induced muscle insulin resistance in humans

    Science.gov (United States)

    Szendroedi, Julia; Yoshimura, Toru; Phielix, Esther; Koliaki, Chrysi; Marcucci, Mellissa; Zhang, Dongyan; Jelenik, Tomas; Müller, Janette; Herder, Christian; Nowotny, Peter; Shulman, Gerald I.; Roden, Michael

    2014-01-01

    Muscle insulin resistance is a key feature of obesity and type 2 diabetes and is strongly associated with increased intramyocellular lipid content and inflammation. However, the cellular and molecular mechanisms responsible for causing muscle insulin resistance in humans are still unclear. To address this question, we performed serial muscle biopsies in healthy, lean subjects before and during a lipid infusion to induce acute muscle insulin resistance and assessed lipid and inflammatory parameters that have been previously implicated in causing muscle insulin resistance. We found that acute induction of muscle insulin resistance was associated with a transient increase in total and cytosolic diacylglycerol (DAG) content that was temporally associated with protein kinase (PKC)θ activation, increased insulin receptor substrate (IRS)-1 serine 1101 phosphorylation, and inhibition of insulin-stimulated IRS-1 tyrosine phosphorylation and AKT2 phosphorylation. In contrast, there were no associations between insulin resistance and alterations in muscle ceramide, acylcarnitine content, or adipocytokines (interleukin-6, adiponectin, retinol-binding protein 4) or soluble intercellular adhesion molecule-1. Similar associations between muscle DAG content, PKCθ activation, and muscle insulin resistance were observed in healthy insulin-resistant obese subjects and obese type 2 diabetic subjects. Taken together, these data support a key role for DAG activation of PKCθ in the pathogenesis of lipid-induced muscle insulin resistance in obese and type 2 diabetic individuals. PMID:24979806

  4. The human insulin gene is part of a large open chromatin domain specific for human islets

    OpenAIRE

    Mutskov, Vesco; Felsenfeld, Gary

    2009-01-01

    Knowledge of how insulin (INS) gene expression is regulated will lead to better understanding of normal and abnormal pancreatic β cell function. We have mapped histone modifications over the INS region, coupled with an expression profile, in freshly isolated islets from multiple human donors. Unlike many other human genes, in which active modifications tend to be concentrated within 1 kb around the transcription start site, these marks are distributed over the entire coding region of INS as w...

  5. An insulin-induced DNA-binding protein for the human growth hormone gene.

    OpenAIRE

    Prager, D; Gebremedhin, S; Melmed, S

    1990-01-01

    The control of gene transcription is usually mediated by transacting transcriptional factors that bind to upstream regulatory elements. As insulin regulates transcription of the growth hormone (GH) gene, we tested nuclear extracts from unstimulated and insulin-stimulated Chinese hamster ovarian (CHO) cells for binding to four human GH (hGH) gene promoter oligonucleotide fragments identified as target-binding sequences by DNAse I footprinting. Using a mobility shift assay, an insulin-induced D...

  6. The effect of feeding frequency on insulin and ghrelin responses in human subjects

    DEFF Research Database (Denmark)

    Solomon, Thomas; Chambers, Edward S; Jeukendrup, Asker E;

    2008-01-01

    Recent work shows that increased meal frequency reduces ghrelin responses in sheep. Human research suggests there is an interaction between insulin and ghrelin. The effect of meal frequency on this interaction is unknown. Therefore, we investigated the effect of feeding frequency on insulin and g...... might be due, at least partially, to the rise in insulin and that high-frequency feeding may disrupt this relationship....

  7. Study of the aggregation of human insulin Langmuir monolayer.

    Science.gov (United States)

    Liu, Wei; Johnson, Sheba; Micic, Miodrag; Orbulescu, Jhony; Whyte, Jeffrey; Garcia, Andrew R; Leblanc, Roger M

    2012-02-21

    The human insulin (HI) Langmuir monolayer at the air-water interface was systematically investigated in the presence and absence of Zn(II) ions in the subphase. HI samples were dissolved in acidic (pH 2) and basic (pH 9) aqueous solutions and then spread at the air-water interface. Spectroscopic data of aqueous solutions of HI show a difference in HI conformation at different pH values. Moreover, the dynamics of the insulin protein showed a dependence on the concentration of Zn(II) ions. In the absence of Zn(II) ions in the subphase, the acidic and basic solutions showed similar behavior at the air-water interface. In the presence of Zn(II) ions in the subphase, the surface pressure-area and surface potential-area isotherms suggest that HI may aggregate at the air-water interface. It was observed that increasing the concentration of Zn(II) ions in the acidic (pH 2) aqueous solution of HI led to an increase of the area at a specific surface pressure. It was also seen that the conformation of HI in the basic (pH 9) medium had a reverse effect (decrease in the surface area) with the increase of the concentration of Zn(II) ions in solution. From the compression-decompression cycles we can conclude that the aggregated HI film at air-water interface is not stable and tends to restore a monolayer of monomers. These results were confirmed from UV-vis and fluorescence spectroscopy analysis. Infrared reflection-absorption and circular dichroism spectroscopy techniques were used to determine the secondary structure and orientation changes of HI by zinc ions. Generally, the aggregation process leads to a conformation change from α-helix to β-strand and β-turn, and at the air-water interface, the aggregation process was likewise seen to induce specific orientations for HI in the acidic and basic media. A proposed surface orientation model is presented here as an explanation to the experimental data, shedding light for further research on the behavior of insulin as a Langmuir

  8. Structure, Aggregation, and Activity of a Covalent Insulin Dimer Formed During Storage of Neutral Formulation of Human Insulin.

    Science.gov (United States)

    Hjorth, Christian Fogt; Norrman, Mathias; Wahlund, Per-Olof; Benie, Andrew J; Petersen, Bent O; Jessen, Christian M; Pedersen, Thomas Å; Vestergaard, Kirsten; Steensgaard, Dorte B; Pedersen, Jan Skov; Naver, Helle; Hubálek, František; Poulsen, Christian; Otzen, Daniel

    2016-04-01

    A specific covalently linked dimeric species of insulin high molecular weight products (HMWPs), formed during prolonged incubation of a neutral pharmaceutical formulation of human insulin, were characterized in terms of tertiary structure, self-association, biological activity, and fibrillation properties. The dimer was formed by a covalent link between A21Asn and B29Lys. It was analyzed using static and dynamic light scattering and small-angle X-ray scattering to evaluate its self-association behavior. The tertiary structure was obtained using nuclear magnetic resonance and X-ray crystallography. The biological activity of HMWP was determined using 2 in vitro assays, and its influence on fibrillation was investigated using Thioflavin T assays. The dimer's tertiary structure was nearly identical to that of the noncovalent insulin dimer, and it was able to form hexamers in the presence of zinc. The dimer exhibited reduced propensity for self-association in the absence of zinc but significantly postponed the onset of fibrillation in insulin formulations. Consistent with its dimeric state, the tested species of HMWP showed little to no biological activity in the used assays. This study is the first detailed characterization of a specific type of human insulin HMWP formed during storage of a marketed pharmaceutical formulation. These results indicate that this specific type of HMWP is unlikely to antagonize the physical stability of the formulation, as HMWP retained a tertiary structure similar to the noncovalent dimer and participated in hexamer assembly in the presence of zinc. In addition, increasing amounts of HMWP reduce the rate of insulin fibrillation.

  9. Protective role of Cys-178 against the inactivation and oligomerization of human insulin-degrading enzyme by oxidation and nitrosylation.

    Science.gov (United States)

    Ralat, Luis A; Ren, Min; Schilling, Alexander B; Tang, Wei-Jen

    2009-12-01

    Insulin-degrading enzyme (IDE), a 110-kDa metalloendopeptidase, hydrolyzes several physiologically relevant peptides, including insulin and amyloid-beta (Abeta). Human IDE has 13 cysteines and is inhibited by hydrogen peroxide and S-nitrosoglutathione (GSNO), donors of reactive oxygen and nitrogen species, respectively. Here, we report that the oxidative burst of BV-2 microglial cells leads to oxidation or nitrosylation of secreted IDE, leading to the reduced activity. Hydrogen peroxide and GSNO treatment of IDE reduces the V(max) for Abeta degradation, increases IDE oligomerization, and decreases IDE thermostability. Additionally, this inhibitory response of IDE is substrate-dependent, biphasic for Abeta degradation but monophasic for a shorter bradykinin-mimetic substrate. Our mutational analysis of IDE and peptide mass fingerprinting of GSNO-treated IDE using Fourier transform-ion cyclotron resonance mass spectrometer reveal a surprising interplay of Cys-178 with Cys-110 and Cys-819 for catalytic activity and with Cys-789 and Cys-966 for oligomerization. Cys-110 is near the zinc-binding catalytic center and is normally buried. The oxidation and nitrosylation of Cys-819 allow Cys-110 to be oxidized or nitrosylated, leading to complete inactivation of IDE. Cys-789 is spatially adjacent to Cys-966, and their nitrosylation and oxidation together trigger the oligomerization and inhibition of IDE. Interestingly, the Cys-178 modification buffers the inhibition caused by Cys-819 modification and prevents the oxidation or nitrosylation of Cys-110. The Cys-178 modification can also prevent the oligomerization-mediated inhibition. Thus, IDE can be intricately regulated by reactive oxygen or nitrogen species. The structure of IDE reveals the molecular basis for the long distance interactions of these cysteines and how they regulate IDE function.

  10. Preparative isolation by high performance liquid chromatography of human insulin B chain produced in escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, N.; Antonio, S.; De Anda, R.; Gosset, G.; Bolivar, F. (Centro de Investigacion sobre Ingenieria Genetica y Biotecnologia, Universidad Nacional Autonoma de Mexico, Apdo. Postal 510-3 Cuernavaca, Mor. 62271 (MX))

    1990-01-01

    This paper reports on a simple method developed for the analytical and preparative purification of human insulin B chain from recombinant origin. Three solvent systems: acetonitrile, isopropanol and methanol, were studied to determine their capacity to resolve the insulin B chain from a mixture of cyanogen bromide generated bacterial peptides. Using a {mu}Bondapak C18 column, it was possible to resolve the insulin B chain in all three systems. On a preparative scale, using a PrePak 500 C18 column with the isopropanol system, it was possible to purify insulin B chain and to obtain a 95% protein recovery.

  11. Structure, antihyperglycemic activity and cellular actions of a novel diglycated human insulin

    DEFF Research Database (Denmark)

    O'Harte, F P; Boyd, A C; McKillop, A M;

    2000-01-01

    Human insulin was glycated under hyperglycemic reducing conditions and a novel diglycated form (M(r) 6135.1 Da) was purified by RP-HPLC. Endoproteinase Glu-C digestion combined with mass spectrometry and automated Edman degradation localized glycation to Gly(1) and Phe(1) of the insulin A- and B......-chains, respectively. Intraperitoneal (i.p.) administration of diglycated insulin to mice alone or in combination with glucose (7 nmol/kg) resulted in a 43-61% and 11-34% reduction in glucose lowering activity, respectively, compared with native insulin. Consistent with these findings, diglycated insulin (10(-9) to 10......(-7) mol/liter) was 22-38% less effective (P insulin in stimulating glucose uptake, glucose oxidation and glycogen production in isolated mouse abdominal muscle....

  12. Common genetic variation in the human CTF1 locus, encoding cardiotrophin-1, determines insulin sensitivity.

    Directory of Open Access Journals (Sweden)

    Stefan Z Lutz

    Full Text Available AIMS/HYPOTHESIS: Recently, cardiotrophin-1, a member of the interleukin-6 family of cytokines was described to protect beta-cells from apoptosis, to improve glucose-stimulated insulin secretion and insulin resistance, and to prevent streptozotocin-induced diabetes in mice. Here, we studied whether common single nucleotide polymorphisms (SNPs in the CTF1 locus, encoding cardiotrophin-1, influence insulin secretion and insulin sensitivity in humans. METHODS: We genotyped 1,771 German subjects for three CTF1 tagging SNPs (rs1046276, rs1458201, and rs8046707. The subjects were metabolically characterized by an oral glucose tolerance test. Subgroups underwent magnetic resonance (MR imaging/spectroscopy and hyperinsulinaemic-euglycaemic clamps. RESULTS: After appropriate adjustment, the minor allele of CTF1 SNP rs8046707 was significantly associated with decreased in vivo measures of insulin sensitivity. The other tested SNPs were not associated with OGTT-derived sensitivity parameters, nor did the three tested SNPs show any association with OGTT-derived parameters of insulin release. In the MR subgroup, SNP rs8046707 was nominally associated with lower visceral adipose tissue. Furthermore, the SNP rs1458201 showed a nominal association with increased VLDL levels. CONCLUSIONS: In conclusion, this study, even though preliminary and awaiting further confirmation by independent replication, provides first evidence that common genetic variation in CTF1 could contribute to insulin sensitivity in humans. Our SNP data indicate an insulin-desensitizing effect of cardiotrophin-1 and underline that cardiotrophin-1 represents an interesting target to influence insulin sensitivity.

  13. Plasma adiponectin concentration is associated with skeletal muscle insulin receptor tyrosine phosphorylation, and low plasma concentration precedes a decrease in whole-body insulin sensitivity in humans

    DEFF Research Database (Denmark)

    Stefan, Norbert; Vozarova, Barbora; Funahashi, Tohru;

    2002-01-01

    -induced tyrosine phosphorylation of the insulin receptor (IR) and also increase whole-body insulin sensitivity. To further characterize the relationship between plasma adiponectin concentration and insulin sensitivity in humans, we examined 1) the cross-sectional association between plasma adiponectin......Adiponectin, the most abundant adipose-specific protein, has been found to be negatively associated with degree of adiposity and positively associated with insulin sensitivity in Pima Indians and other populations. Moreover, adiponectin administration to rodents has been shown to increase insulin...... concentration and skeletal muscle IR tyrosine phosphorylation and 2) the prospective effect of plasma adiponectin concentration at baseline on change in insulin sensitivity. Fasting plasma adiponectin concentration, body composition (hydrodensitometry or dual energy X-ray absorptiometry), insulin sensitivity...

  14. Pretreatment with insulin enhances anticancer functions of 5-fluorouracil in human esophageal and colonic cancer cells

    Institute of Scientific and Technical Information of China (English)

    Ke ZOU; Ji-hang JU; Hong XIE

    2007-01-01

    Aim: To investigate the effects of insulin on enhancing 5-fluorouracil (5-FU) anti-cancer functions and its mechanisms in the human esophageal cancer cell line (Eca 109) and human colonic cancer cell line (Ls-174-t). Methods: The effect of insulin/5-FU combination treatment on the growth of Eca 109 and Ls-174-t cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. After insulin treatment or insulin/5-FU treatment, cell cycle distri-bution of both cell lines was analyzed by flow cytometry. Western blot assay was used to assess the expression of caspase-3 and thymidylate synthase (TS).Apoptosis was detected by flow cytometry, DNA fragmentation assay, and termi-nal transferase dUTP nick end labeling assay (TUNEL). Moreover, the changes of 5-FU uptake after insulin pretreatment were detected by HPLC assay and Western blot analysis. Results: We found that insulin enhanced the inhibitory effect of 5-FU on cell proliferation when Eca 109 cells and Ls- 174-t cells were pretreated with insulin for the appropriate time. Insulin increased the cell number of the S phase and the uptake of 5-FU. Insulin/5-FU treatment enhanced apoptosis of tumor cells and upregulated the expression of cleaved caspase-3 compared with 5-FU treatment.Moreover, insulin/5-FU treatment induced the changes of free TS and the TS ternary complex level compared with 5-FU treatment in Eca 109 and Ls-174-t cells.Conclusion: These data suggest that insulin enhances anticancer functions of 5-FU when it is treated before 5-FU for the appropriate time in human esophageal and colonic cancer cell lines.

  15. MCF-7 human mammary adenocarcinoma cells exhibit augmented responses to human insulin on a collagen IV surface

    DEFF Research Database (Denmark)

    Listov-Saabye, Nicolai; Jensen, Marianne Blirup; Kiehr, Benedicte;

    2009-01-01

    was significantly more mitogenic than native insulin, validating the ability of the assay to identify hypermitogenic human insulin analogs. With MCF-7 cells on a collagen IV surface, the ranking of mitogens was maintained, but fold mitogenic responses and dynamic range and steepness of dose-response curves were...

  16. In nondiabetic, human immunodeficiency virus-infected patients with lipodystrophy, hepatic insulin extraction and posthepatic insulin clearance rate are decreased in proportion to insulin resistance

    DEFF Research Database (Denmark)

    Haugaard, Steen B; Andersen, Ove; Hansen, Birgitte R;

    2005-01-01

    , human immunodeficiency virus (HIV)-infected patients with and without lipodystrophy. We studied 18 HIV-infected patients with lipodystrophy (LIPO) on antiretroviral therapy and 25 HIV-infected patients without lipodystrophy (controls) of whom 18 were on antiretroviral therapy and 7 were not. Posthepatic...... > .1). Our data suggest that HEXi and MCRi are decreased in proportion to the degree of insulin resistance in nondiabetic HIV-infected patients with lipodystrophy....

  17. Polymorphisms of Exon 17 of Insulin-Receptor Gene in Pathogenesis of Human Disorders With Insulin Resistance

    Institute of Scientific and Technical Information of China (English)

    LU WANG; JIE MI; XIAO-YUAN ZHAO; JIAN-XIN WU; HONG CHENG; ZHI-KUN ZHANG; XIU-YUAN DING; DONG-QING HOU; HUILI

    2004-01-01

    To investigate the relationship between polymorphisms of insulin-receptor (INSR) gene and insulin resistance in a population-based study in China. Methods Polymerase Chain Reaction (PCR) was used to the amplify Exon 17 of INSR gene and all amplified products were analyzed by direct sequencing. Results Six single-nucleotide polymorphisms (SNPs) were found at the following loci: T to TC at the locus of 10699 (Tyr984), G to GC at the locus of 10731 (Glu994), Deletion G at the locus of 10798 (Asp1017), C to T/TC at the locus of 10923 (His1058), C to CA at the locus of 10954 (Leu1069), and T to TA at the locus of 10961 (Phe1071), which might not change the amino acid sequence. The data were in agreement with the test of Hardy-Weinberg balance (P>0.05). Among the 345 cases, all clinical indices were higher in males than in females except for HDL cholesterol (P0.05). After sex stratification in analysis,all allele frequencies on the six loci of SNPs of Exon 17 had different distributions between the insulin resistant group and the control group, but P>0.05. Conclusion SNPs of Exon 17 of INSR gene are unlikely to play a direct role in the pathogenesis of human disorders with insulin resistance.

  18. Effect of Human Myotubes-Derived Media on Glucose-Stimulated Insulin Secretion

    Directory of Open Access Journals (Sweden)

    Maria L. Mizgier

    2017-01-01

    Full Text Available Fasting to postprandial transition requires a tight adjustment of insulin secretion to its demand, so tissue (e.g., skeletal muscle glucose supply is assured while hypo-/hyperglycemia are prevented. High muscle glucose disposal after meals is pivotal for adapting to increased glycemia and might drive insulin secretion through muscle-released factors (e.g., myokines. We hypothesized that insulin influences myokine secretion and then increases glucose-stimulated insulin secretion (GSIS. In conditioned media from human myotubes incubated with/without insulin (100 nmol/L for 24 h, myokines were qualitatively and quantitatively characterized using an antibody-based array and ELISA-based technology, respectively. C57BL6/J mice islets and Wistar rat beta cells were incubated for 24 h with control and conditioned media from noninsulin- and insulin-treated myotubes prior to GSIS determination. Conditioned media from insulin-treated versus nontreated myotubes had higher RANTES but lower IL6, IL8, and MCP1 concentration. Qualitative analyses revealed that conditioned media from noninsulin- and insulin-treated myotubes expressed 32 and 23 out of 80 myokines, respectively. Islets incubated with conditioned media from noninsulin-treated myotubes had higher GSIS versus control islets (p<0.05. Meanwhile, conditioned media from insulin-treated myotubes did not influence GSIS. In beta cells, GSIS was similar across conditions. In conclusion, factors being present in noninsulin-stimulated muscle cell-derived media appear to influence GSIS in mice islets.

  19. Effect of Human Myotubes-Derived Media on Glucose-Stimulated Insulin Secretion

    Science.gov (United States)

    Cataldo, Luis R.; Gutierrez, Juan; Santos, José L.; Casas, Mariana; Contreras-Ferrat, Ariel E.; Moro, Cedric; Bouzakri, Karim

    2017-01-01

    Fasting to postprandial transition requires a tight adjustment of insulin secretion to its demand, so tissue (e.g., skeletal muscle) glucose supply is assured while hypo-/hyperglycemia are prevented. High muscle glucose disposal after meals is pivotal for adapting to increased glycemia and might drive insulin secretion through muscle-released factors (e.g., myokines). We hypothesized that insulin influences myokine secretion and then increases glucose-stimulated insulin secretion (GSIS). In conditioned media from human myotubes incubated with/without insulin (100 nmol/L) for 24 h, myokines were qualitatively and quantitatively characterized using an antibody-based array and ELISA-based technology, respectively. C57BL6/J mice islets and Wistar rat beta cells were incubated for 24 h with control and conditioned media from noninsulin- and insulin-treated myotubes prior to GSIS determination. Conditioned media from insulin-treated versus nontreated myotubes had higher RANTES but lower IL6, IL8, and MCP1 concentration. Qualitative analyses revealed that conditioned media from noninsulin- and insulin-treated myotubes expressed 32 and 23 out of 80 myokines, respectively. Islets incubated with conditioned media from noninsulin-treated myotubes had higher GSIS versus control islets (p < 0.05). Meanwhile, conditioned media from insulin-treated myotubes did not influence GSIS. In beta cells, GSIS was similar across conditions. In conclusion, factors being present in noninsulin-stimulated muscle cell-derived media appear to influence GSIS in mice islets. PMID:28286777

  20. In nondiabetic, human immunodeficiency virus-infected patients with lipodystrophy, hepatic insulin extraction and posthepatic insulin clearance rate are decreased in proportion to insulin resistance

    DEFF Research Database (Denmark)

    Haugaard, Steen B; Andersen, Ove; Hansen, Birgitte R;

    2005-01-01

    In healthy, nondiabetic individuals with insulin resistance, fasting insulin is inversely correlated to the posthepatic insulin clearance rate (MCRi) and the hepatic insulin extraction (HEXi). We investigated whether similar early mechanisms to facilitate glucose homeostasis exist in nondiabetic...... > .1). Our data suggest that HEXi and MCRi are decreased in proportion to the degree of insulin resistance in nondiabetic HIV-infected patients with lipodystrophy....

  1. Effect of insulin and glucose on adenosine metabolizing enzymes in human B lymphocytes.

    Science.gov (United States)

    Kocbuch, Katarzyna; Sakowicz-Burkiewicz, Monika; Grden, Marzena; Szutowicz, Andrzej; Pawelczyk, Tadeusz

    2009-01-01

    In diabetes several aspects of immunity are altered, including the immunomodulatory action of adenosine. Our study was undertaken to investigate the effect of different glucose and insulin concentrations on activities of adenosine metabolizing enzymes in human B lymphocytes line SKW 6.4. The activity of adenosine deaminase in the cytosolic fraction was very low and was not affected by different glucose concentration, but in the membrane fraction of cells cultured with 25 mM glucose it was decreased by about 35% comparing to the activity in cells maintained in 5 mM glucose, irrespective of insulin concentration. The activities of 5'-nucleotidase (5'-NT) and ecto-5'-NT in SKW 6.4 cells depended on insulin concentration, but not on glucose. Cells cultured with 10(-8) M insulin displayed an about 60% lower activity of cytosolic 5'-NT comparing to cells maintained at 10(-11) M insulin. The activity of ecto-5'-NT was decreased by about 70% in cells cultured with 10(-8) M insulin comparing to cells grown in 10(-11) M insulin. Neither insulin nor glucose had an effect on adenosine kinase (AK) activity in SKW 6.4 cells or in human B cells isolated from peripheral blood. The extracellular level of adenosine and inosine during accelerated catabolism of cellular ATP depended on glucose, but not on insulin concentration. Concluding, our study demonstrates that glucose and insulin differentially affect the activities of adenosine metabolizing enzymes in human B lymphocytes, but changes in those activities do not correlate with the adenosine level in cell media during accelerated ATP catabolism, implying that nucleoside transport is the primary factor determining the extracellular level of adenosine.

  2. The human insulin gene is part of a large open chromatin domain specific for human islets.

    Science.gov (United States)

    Mutskov, Vesco; Felsenfeld, Gary

    2009-10-13

    Knowledge of how insulin (INS) gene expression is regulated will lead to better understanding of normal and abnormal pancreatic beta cell function. We have mapped histone modifications over the INS region, coupled with an expression profile, in freshly isolated islets from multiple human donors. Unlike many other human genes, in which active modifications tend to be concentrated within 1 kb around the transcription start site, these marks are distributed over the entire coding region of INS as well. Moreover, a region of approximately 80 kb around the INS gene, which contains the {tyrosine hydroxylase (TH)-(INS)-insulin-like growth factor 2 antisense (IGF2AS)-insulin-like growth factor 2 (IGF2)} gene cluster, unusually is marked by almost uniformly elevated levels of histone acetylation and H3K4 dimethylation, extending both downstream into IGF2 and upstream beyond the TH gene. This is accompanied by islet specific coordinate expression with INS of the neighboring TH and IGF2 genes. The presence of islet specific intergenic transcripts suggests their possible function in the maintenance of this unusual large open chromatin domain.

  3. Crystallization of Enantiomerically Pure Proteins from Quasi-Racemic Mixtures: Structure Determination by X-Ray Diffraction of Isotope-Labeled Ester Insulin and Human Insulin.

    Science.gov (United States)

    Mandal, Kalyaneswar; Dhayalan, Balamurugan; Avital-Shmilovici, Michal; Tokmakoff, Andrei; Kent, Stephen B H

    2016-03-01

    As a part of a program aimed towards the study of the dynamics of human insulin-protein dimer formation using two-dimensional infrared spectroscopy, we used total chemical synthesis to prepare stable isotope labeled [(1-(13) C=(18) O)Phe(B24) )] human insulin, via [(1-(13) C=(18) O)Phe(B24) )] ester insulin as a key intermediate product that facilitates folding of the synthetic protein molecule (see preceding article). Here, we describe the crystal structure of the synthetic isotope-labeled ester insulin intermediate and the product synthetic human insulin. Additionally, we present our observations on hexamer formation with these two proteins in the absence of phenol derivatives and/or Zn metal ions. We also describe and discuss the fractional crystallization of quasi-racemic protein mixtures containing each of these two synthetic proteins.

  4. Fetal and perinatal outcomes in type 1 diabetes pregnancy : a randomized study comparing insulin aspart with human insulin in 322 subjects

    NARCIS (Netherlands)

    Hod, Moshe; Damm, Peter; Kaaja, Risto; Visser, Gerard H. A.; Dunne, Fidelma; Demidova, Irina; Hansen, Anne-Sofie Pade; Mersebach, Henriette

    2008-01-01

    OBJECTIVE: The objective of the study was a comparison of insulin aspart (IAsp) with human insulin (HI) in basal-bolus therapy with neutral protamine Hagedorn for fetal and perinatal outcomes of type 1 diabetes in pregnancy. STUDY DESIGN: This was a randomized, parallel, open-label, controlled, mult

  5. Insulin and leptin enhance human sperm motility, acrosome reaction and nitric oxide production

    Institute of Scientific and Technical Information of China (English)

    Fanuel Lampiao; Stefan S. du Plessis

    2008-01-01

    Aim: To investigate the in vitro effects of insulin and leptin on human sperm motility, viability, acrosome reaction and nitric oxide (NO) production. Methods: Washed human spermatozoa from normozoospermic donors were treated with insulin (10 μIU) and leptin (10 nmol). Insulin and leptin effects were blocked by inhibition of their intracellular effector, phosphotidylinositol 3-kinase (PI3K), by wortmannin (10 μmol) 30 min prior to insulin and leptin being given. Computer-assisted semen analysis was used to assess motility after 1, 2 and 3 h of incubation. Viability was assessed by fluorescence-activated cell sorting using propidium iodide as a fluorescent probe. Acrosome-reacted cells were observed under a fluorescent microscope using fluorescein-isothiocyanate-Pisum sativum agglutinin as a probe. NO was measured after treating the sperm with 4,5-diaminofluorescein-2/diacetate (DAF-2/DA) and analyzed by fluorescence-activated cell sorting. Results: Insulin and leptin significantly increased total motility, progressive motility and acrosome reaction, as well as NO production. Conclusion: This study showed the in vitro beneficial effects of insulin and leptin on human sperm function. These hormones could play a role in enhancing the fertilization capacity of human spermatozoa.

  6. Reduced DPP4 activity improves insulin signaling in primary human adipocytes.

    Science.gov (United States)

    Röhrborn, Diana; Brückner, Julia; Sell, Henrike; Eckel, Jürgen

    2016-03-11

    DPP4 is a ubiquitously expressed cell surface protease which is also released to the circulation as soluble DPP4 (sDPP4). Recently, we identified DPP4 as a novel adipokine oversecreted in obesity and thus potentially linking obesity to the metabolic syndrome. Furthermore, sDPP4 impairs insulin signaling in an autocrine and paracrine fashion in different cell types. However, it is still unknown which functional role DPP4 might play in adipocytes. Therefore, primary human adipocytes were treated with a specific DPP4 siRNA. Adipocyte differentiation was not affected by DPP4 silencing. Interestingly, DPP4 reduction improved insulin responsiveness of adipocytes at the level of insulin receptor, proteinkinase B (Akt) and Akt substrate of 160 kDa. To investigate whether the observed effects could be attributed to the enzymatic activity of DPP4, human adipocytes were treated with the DPP4 inhibitors sitagliptin and saxagliptin. Our data show that insulin-stimulated activation of Akt is augmented by DPP4 inhibitor treatment. Based on our previous observation that sDPP4 induces insulin resistance in adipocytes, and that adipose DPP4 levels are higher in obese insulin-resistant patients, we now suggest that the abundance of DPP4 might be a regulator of adipocyte insulin signaling.

  7. Impaired tethering and fusion of GLUT4 vesicles in insulin-resistant human adipose cells.

    Science.gov (United States)

    Lizunov, Vladimir A; Lee, Jo-Ping; Skarulis, Monica C; Zimmerberg, Joshua; Cushman, Samuel W; Stenkula, Karin G

    2013-09-01

    Systemic glucose homeostasis is profoundly influenced by adipose cell function. Here we investigated GLUT4 dynamics in living adipose cells from human subjects with varying BMI and insulin sensitivity index (Si) values. Cells were transfected with hemagglutinin (HA)-GLUT4-green fluorescent protein (GFP)/mCherry (red fluorescence), and were imaged live using total internal reflection fluorescence and confocal microscopy. HA-GLUT4-GFP redistribution to the plasma membrane (PM) was quantified by surface-exposed HA epitope. In the basal state, GLUT4 storage vesicle (GSV) trafficking to and fusion with the PM were invariant with donor subject Si, as was total cell-surface GLUT4. In cells from insulin-sensitive subjects, insulin augmented GSV tethering and fusion approximately threefold, resulting in a corresponding increase in total PM GLUT4. However, with decreasing Si, these effects diminished progressively. All insulin-induced effects on GLUT4 redistribution and trafficking correlated strongly with Si and only weakly with BMI. Thus, while basal GLUT4 dynamics and total cell-surface GLUT4 are intact in human adipose cells, independent of donor Si, cells from insulin-resistant donors show markedly impaired GSV tethering and fusion responses to insulin, even after overnight culture. This altered insulin responsiveness is consistent with the hypothesis that adipose cellular dysfunction is a primary contributor to systemic metabolic dysfunction.

  8. Potential role of TBC1D4 in enhanced post-exercise insulin action in human skeletal muscle

    DEFF Research Database (Denmark)

    Treebak, Jonas Thue; Frøsig, Christian; Pehmøller, Christian

    2009-01-01

    insulin stimulation. CONCLUSION/INTERPRETATION: We provide evidence for site-specific phosphorylation of TBC1D4 in human skeletal muscle in response to physiological hyperinsulinaemia. The data support the idea that TBC1D4 is a nexus for insulin- and exercise-responsive signals that may mediate increased...... insulin action after exercise....

  9. Acute encephalopathy with biphasic seizures and late reduced diffusion

    Directory of Open Access Journals (Sweden)

    Saroj S Yadav

    2013-01-01

    Full Text Available Acute encephalopathy with biphasic seizures and reduced diffusion (AESD is a syndrome of encephalopathy characterized by biphasic seizures and altered consciousness in the acute stage followed in the subacute stage by restricted diffusion in the subcortical white matter on magnetic resonance imaging. The etiology of AESD has been attributed to viral infection like influenza A and human herpes virus 6. The exact pathogenesis of AESD is uncertain. Here we report a case of AESD, diagnosed based on clinicoradiological correlation.

  10. Low-frequency physiological activation of the vestibular utricle causes biphasic modulation of skin sympathetic nerve activity in humans.

    Science.gov (United States)

    Grewal, Tarandeep; Dawood, Tye; Hammam, Elie; Kwok, Kenny; Macefield, Vaughan G

    2012-07-01

    We have previously shown that sinusoidal galvanic vestibular stimulation, a means of selectively modulating vestibular afferent activity, can cause partial entrainment of sympathetic outflow to muscle and skin in human subjects. However, it influences the firing of afferents from the entire vestibular apparatus, including the semicircular canals. Here, we tested the hypothesis that selective stimulation of one set of otolithic organs-those located in the utricle, which are sensitive to displacement in the horizontal axis-could entrain sympathetic nerve activity. Skin sympathetic nerve activity (SSNA) was recorded via tungsten microelectrodes inserted into cutaneous fascicles of the common peroneal nerve in 10 awake subjects, seated (head vertical, eyes closed) on a motorised platform. Slow sinusoidal accelerations-decelerations (~4 mG) were applied in the X (antero-posterior) or Y (medio-lateral) direction at 0.08 Hz; composite movements in both directions were also applied. Subjects either reported feeling a vague sense of movement (with no sense of direction) or no movement at all. Nevertheless, cross-correlation analysis revealed a marked entrainment of SSNA for all types of movements: vestibular modulation was 97 ± 3 % for movements in the X axis and 91 ± 5 % for displacements in the Y axis. For each sinusoidal cycle, there were two major peaks of modulation-one associated with acceleration as the platform moved forward or to the side, and one associated with acceleration in the opposite direction. We interpret these observations as reflecting inertial displacement of the stereocilia within the utricle during acceleration, which causes a robust vestibulosympathetic reflex.

  11. Separation of human, bovine, and porcine insulins, three very closely related proteins, by micellar electrokinetic chromatography.

    Science.gov (United States)

    Lamalle, Caroline; Roland, Diane; Crommen, Jacques; Servais, Anne-Catherine; Fillet, Marianne

    2015-10-01

    Human, bovine, and porcine insulins are small proteins with very closely related amino acid sequences, which makes their separation challenging. In this study, we took advantage of the high-resolution power of CE, and more particularly of micellar electrokinetic chromatography, to separate those biomolecules. Among several surfactants, perfluorooctanoic acid ammonium salt was selected. Then, using a design of experiments approach, the optimal BGE composition was found to consist of 50 mM ammonium acetate pH 9.0, 65 mM perfluorooctanoic acid ammonium salt, and 4% MeOH. The three insulins could be separated within 12 min with a satisfactory resolution. This method could be useful to detect possible counterfeit pharmaceutical formulations. Indeed, it would be easy to determine if human insulin was replaced by bovine or porcine insulin.

  12. Differential roles of CIDEA and CIDEC in insulin-induced anti-apoptosis and lipid droplet formation in human adipocytes.

    Science.gov (United States)

    Ito, Minoru; Nagasawa, Michiaki; Hara, Tomoko; Ide, Tomohiro; Murakami, Koji

    2010-07-01

    Both insulin and the cell death-inducing DNA fragmentation factor-alpha-like effector (CIDE) family play important roles in apoptosis and lipid droplet formation. However, regulation of the CIDE family by insulin and the contribution of the CIDE family to insulin actions remain unclear. Here, we investigated whether insulin regulates expression of the CIDE family and which subtypes contribute to insulin-induced anti-apoptosis and lipid droplet formation in human adipocytes. Insulin decreased CIDEA and increased CIDEC but not CIDEB mRNA expression. Starvation-induced apoptosis in adipocytes was significantly inhibited when insulin decreased the CIDEA mRNA level. Small interfering RNA-mediated depletion of CIDEA inhibited starvation-induced apoptosis similarly to insulin and restored insulin deprivation-reduced adipocyte number, whereas CIDEC depletion did not. Lipid droplet size of adipocytes was increased when insulin increased the CIDEC mRNA level. In contrast, insulin-induced enlargement of lipid droplets was markedly abrogated by depletion of CIDEC but not CIDEA. Furthermore, depletion of CIDEC, but not CIDEA, significantly increased glycerol release from adipocytes. These results suggest that CIDEA and CIDEC are novel genes regulated by insulin in human adipocytes and may play key roles in the effects of insulin, such as anti-apoptosis and lipid droplet formation.

  13. Insulin action in human thighs after one-legged immobilization

    DEFF Research Database (Denmark)

    Richter, Erik; Kiens, Bente; Mizuno, M.;

    1989-01-01

    -acyl-CoA-dehydrogenase in the vastus lateralis muscle by 9 and 14%, respectively, and thigh volume by 5%. After 7 days of immobilization, a two-step euglycemic hyperinsulinemic clamp procedure combined with arterial and bilateral femoral venous catheterization was performed. Insulin action on glucose uptake and tyrosine release...

  14. Transplanted human pancreatic islets after long-term insulin independence

    DEFF Research Database (Denmark)

    Muller, Y D; Gupta, Shashank; Morel, P;

    2013-01-01

    independence. Islets were pooled from two donors with respectively one and five HLA mismatches. Insulin-positive islets were found throughout the right and left liver, and absent in the pancreas. Two- and three-dimensional analysis showed that islets lost their initial rounded and compact morphology, had...

  15. An update on the treatment of type 1 and type 2 diabetes mellitus: focus on insulin detemir, a long-acting human insulin analog

    Directory of Open Access Journals (Sweden)

    Katarina Raslova

    2010-05-01

    Full Text Available Katarina RaslovaMetabolic Center Ltd and Slovak Medical University, Bratislava, Slovak RepublicAbstract: Basal insulin analogs are used to minimize unpredictable processes of NPH insulin. Modification of the human insulin molecule results in a slower distribution to peripheral target tissues, a longer duration of action with stable concentrations and thus a lower rate of hypoglycemia. Insulin detemir is a basal insulin analog that provides effective therapeutic options for patients with type 1 and type 2 diabetes. For glycemic control, no significant differences were found in HbA1c levels compared with NPH and insulin glargine. It is comparable with insulin glargine in significantly reducing rates of all types of hypoglycemia. Clinical studies have demonstrated that detemir is responsible for significantly lower within-subject variability and no or less weight gain than NPH insulin and glargine. Recent pharmacodynamic studies have shown that detemir can be used once daily in many patients with diabetes. Together with patient-friendly injection devices and dose adjustments, it provides a treatment option with the potential to lower the key barriers of adherence to insulin therapy in type 2 diabetes. Recent guidelines for treatment of type 2 diabetes suggest starting intensive therapy of hyperglycemia at an early stage of diabetes and recommend therapeutic options that provide the possibility of reaching HbA1c goals individually, with a low risk of hypoglycemia or other adverse effects of treatment. The properties of insulin detemir match these requirements.Keywords: insulin analog, insulin detemir, diabetes mellitus, hypoglycemia, within-subject variability

  16. Celastrol Protects against Antimycin A-Induced Insulin Resistance in Human Skeletal Muscle Cells

    Directory of Open Access Journals (Sweden)

    Mohamad Hafizi Abu Bakar

    2015-05-01

    Full Text Available Mitochondrial dysfunction and inflammation are widely accepted as key hallmarks of obesity-induced skeletal muscle insulin resistance. The aim of the present study was to evaluate the functional roles of an anti-inflammatory compound, celastrol, in mitochondrial dysfunction and insulin resistance induced by antimycin A (AMA in human skeletal muscle cells. We found that celastrol treatment improved insulin-stimulated glucose uptake activity of AMA-treated cells, apparently via PI3K/Akt pathways, with significant enhancement of mitochondrial activities. Furthermore, celastrol prevented increased levels of cellular oxidative damage where the production of several pro-inflammatory cytokines in cultures cells was greatly reduced. Celastrol significantly increased protein phosphorylation of insulin signaling cascades with amplified expression of AMPK protein and attenuated NF-κB and PKC θ activation in human skeletal muscle treated with AMA. The improvement of insulin signaling pathways by celastrol was also accompanied by augmented GLUT4 protein expression. Taken together, these results suggest that celastrol may be advocated for use as a potential therapeutic molecule to protect against mitochondrial dysfunction-induced insulin resistance in human skeletal muscle cells.

  17. Differential interaction of Apolipoprotein-E isoforms with insulin receptors modulates brain insulin signaling in mutant human amyloid precursor protein transgenic mice.

    Science.gov (United States)

    Chan, Elizabeth S; Chen, Christopher; Cole, Gregory M; Wong, Boon-Seng

    2015-09-08

    It is unclear how human apolipoprotein E4 (ApoE4) increases the risk for Alzheimer's disease (AD). Although Aβ levels can lead to insulin signaling impairment, these experiments were done in the absence of human ApoE. To examine ApoE role, we crossed the human ApoE-targeted replacement mice with mutant human amyloid precursor protein (APP) mice. In 26 week old mice with lower Aβ levels, the expression and phosphorylation of insulin signaling proteins remained comparable among APP, ApoE3xAPP and ApoE4xAPP mouse brains. When the mice aged to 78 weeks, these proteins were markedly reduced in APP and ApoE4xAPP mouse brains. While Aβ can bind to insulin receptor, how ApoE isoforms modulate this interaction remains unknown. Here, we showed that ApoE3 had greater association with insulin receptor as compared to ApoE4, regardless of Aβ42 concentration. In contrast, ApoE4 bound more Aβ42 with increasing peptide levels. Using primary hippocampal neurons, we showed that ApoE3 and ApoE4 neurons are equally sensitive to physiological levels of insulin. However, in the presence of Aβ42, insulin failed to elicit a downstream response only in ApoE4 hippocampal neurons. Taken together, our data show that ApoE genotypes can modulate this Aβ-mediated insulin signaling impairment.

  18. Expression of human insulin gene wrapped with chitosan nanoparticles in NIH3T3 cells and diabetic rats

    Institute of Scientific and Technical Information of China (English)

    Li NIU; Yan-cheng XU; Hai-ying XIE; Zhe DAI; Hui-qin TANG

    2008-01-01

    Aim: To study the expression of human insulin gene wrapped with chitosan nanoparticles in NIH3T3 cells and diabetic rats. Methods: pCMV.Ins, an expression plasmid of the human insulin gene, was constructed. In total, 100 μg pCMV.Ins wrapped with chitosan nanoparticles (chitosan-pCMV.Ins) was transfected to NIH3T3 cells and diabetes rats through lavage and coloclysis, respectively. The transfected cells were grown in Dulbecco's modified Eagle's medium, containing G418, for 72 h after transfection. The clones were selected and continued to grow in G418 medium for 24 d. The expression of human insulin was detected by immunohistochemistry. Human insulin in the culture medium of transfected cells was measured. Fasting blood glucose and plasma human insulin of diabetic rats were measured for 5 d after transfection. RT-PCR and Western blotting were performed to confirm the expression of the human insulin gene in diabetic rats. Results: Approximately 10% of NIH3T3 cells transfected by chitosan-pCMV.Ins expressed human insulin. Human insulin in the culture medium of NIH3T3 cells transfected by chitosan-pCMV.Ins significantly increased compared with that of the control group (P<0.01). Fasting blood glucose levels of the lavage group and the coloclysis group decreased significantly in 5 d (P<0.01) in comparison, while plasma insulin levels were much higher (P<0.01). The human insulin gene mRNA and human insulin were only detected in the lavage and the coloclysis groups. Conclusion: The human insulin gene can be transfected and expressed successfully by chitosan-pCMV.Ins in NIH3T3 cells and diabetes rats, which indicates that chitosan is a promising, non-viral vector for gene expression.

  19. St. John's Wort inhibits insulin signaling in murine and human adipocytes.

    Science.gov (United States)

    Richard, Allison J; Amini, Zhaleh J; Ribnicky, David M; Stephens, Jacqueline M

    2012-04-01

    Adipocytes are insulin-sensitive cells that play a major role in energy homeostasis. Obesity is the primary disease of fat cells and a major risk factor for the development of Type 2 diabetes, cardiovascular disease, and metabolic syndrome. The use of botanicals in the treatment of metabolic diseases is an emerging area of research. In previous studies, we screened over 425 botanical extracts for their ability to modulate adipogenesis and insulin sensitivity. We identified St. John's Wort (SJW) extracts as inhibitors of adipogenesis of 3T3-L1 cells and demonstrated that these extracts also inhibited insulin-sensitive glucose uptake in mature fat cells. In these follow-up studies we have further characterized the effects of SJW on insulin action in both murine and human fat cells. We have shown that SJW also attenuates insulin-sensitive glucose uptake in human adipocytes. Moreover, SJW inhibits IRS-1 tyrosine phosphorylation in both murine and human fat cells. Botanical extracts are complex mixtures. Many bioactive compounds have been identified in SJW, including hypericin (HI) and hyperforin (HF). We have examined the ability of HI and HF, purified from SJW, to modulate adipocyte development and insulin action in mature adipocytes. Our novel studies indicate that the profound effects of SJW on adipogenesis, IRS-1 activation, and insulin-stimulated glucose uptake are not mediated by HI and/or HF. Nonetheless, we propose that extracts of SJW may contribute to adipocyte related diseases by limiting differentiation of preadipocytes and significantly inducing insulin resistance in mature fat cells.

  20. Human muscle fiber type-specific insulin signaling: impact of obesity and type 2 diabetes.

    Science.gov (United States)

    Albers, Peter H; Pedersen, Andreas J T; Birk, Jesper B; Kristensen, Dorte E; Vind, Birgitte F; Baba, Otto; Nøhr, Jane; Højlund, Kurt; Wojtaszewski, Jørgen F P

    2015-02-01

    Skeletal muscle is a heterogeneous tissue composed of different fiber types. Studies suggest that insulin-mediated glucose metabolism is different between muscle fiber types. We hypothesized that differences are due to fiber type-specific expression/regulation of insulin signaling elements and/or metabolic enzymes. Pools of type I and II fibers were prepared from biopsies of the vastus lateralis muscles from lean, obese, and type 2 diabetic subjects before and after a hyperinsulinemic-euglycemic clamp. Type I fibers compared with type II fibers have higher protein levels of the insulin receptor, GLUT4, hexokinase II, glycogen synthase (GS), and pyruvate dehydrogenase-E1α (PDH-E1α) and a lower protein content of Akt2, TBC1 domain family member 4 (TBC1D4), and TBC1D1. In type I fibers compared with type II fibers, the phosphorylation response to insulin was similar (TBC1D4, TBC1D1, and GS) or decreased (Akt and PDH-E1α). Phosphorylation responses to insulin adjusted for protein level were not different between fiber types. Independently of fiber type, insulin signaling was similar (TBC1D1, GS, and PDH-E1α) or decreased (Akt and TBC1D4) in muscle from patients with type 2 diabetes compared with lean and obese subjects. We conclude that human type I muscle fibers compared with type II fibers have a higher glucose-handling capacity but a similar sensitivity for phosphoregulation by insulin.

  1. Influence of glucocorticoids and growth hormone on insulin sensitivity in humans.

    Science.gov (United States)

    Yuen, K C J; Chong, L E; Riddle, M C

    2013-06-01

    The seminal concept proposed by Sir Harold Himsworth more than 75 years ago that a large number of patients with diabetes were 'insulin insensitive', now termed insulin resistance, has now expanded to include several endocrine syndromes, namely those of glucocorticoid excess, and growth hormone excess and deficiency. Synthetic glucocorticoids are increasingly used to treat a wide variety of chronic diseases, whereas the beneficial effects of recombinant growth hormone replacement therapy in children and adults with growth hormone deficiency have now been well-recognized for over 25 years. However, clinical and experimental studies have established that increased circulating levels of glucocorticoids and growth hormone can also lead to worsening of insulin resistance, glucose intolerance, overt diabetes mellitus and cardiovascular disease. Improved understanding of the physiological 24-h rhythmicity of glucocorticoid and growth hormone secretion and its influence on the dawn phenomenon and the Staub-Trauggot effect has therefore led to renewed interest in studies on the mechanisms of insulin resistance induced by exogenous administration of glucocorticoids and growth hormone in humans. In this review, we describe the physiological events that result from the presence of resistance to insulin action at the level of skeletal muscle, adipose tissue, and liver, describe the known mechanisms of glucocorticoid- and growth hormone-mediated insulin resistance, and provide an update of the contributions of glucocorticoids and growth hormone to understanding the pathophysiology of insulin resistance and its effects on several endocrine syndromes.

  2. Human growth hormone binding and stimulation of insulin biosynthesis in cloned rat insulinoma cells

    DEFF Research Database (Denmark)

    Billestrup, Nils

    1985-01-01

    Binding of 125I labelled human growth hormone to cloned insulin producing RIN-5AH cells is described. Binding was specific for somatotropic hormones since both human and rat growth hormone could compete for binding sites, whereas much higher concentrations of lactogenic hormones were needed...

  3. The human insulin-like growth factor II gene contains two development-specific promoters

    NARCIS (Netherlands)

    Pagter-Holthuizen, P. de; Jansen, M.; Schaik, F.M.A.; Kammen, R. van der; Oosterwijk, C.; Brande, J.L. van den; Sussenbach, J.S.

    1987-01-01

    The insulin-like growth factors (IGF) play an important role in fetal and postnatal development. Recently, the nucleotide sequences of the cDNAs encoding IGF-I and IGF-II and part of the human IGF genes were reported. In this communication we describe two distinct IGF-II cDNAs isolated from a human

  4. The Expanding Pathogenic Role of Insulin Resistance in Human Disease.

    Science.gov (United States)

    2014-01-07

    The December 2011 issue of Diabetic Medicine celebrated the outstanding personal contributions of the renowned clinical scientist Prof. Sir Harold Himsworth in characterizing impaired insulin action in relation to phenotypes of diabetes. The commissioned articles in the special issue of the journal were assembled in recognition of the publication in 1936 of a landmark paper in which Himsworth summarized his innovative research, to which much of our current understanding of insulin resistance can be readily traced. The collection of invited articles that marked the 75th anniversary of the Lancet publication provided a state-of-the-art summary from internationally renowned investigators of what has become an increasingly diverse field reaching into myriad aspects of clinical medicine. This article is protected by copyright. All rights reserved.

  5. Structural meta-analysis of regular human insulin in pharmaceutical formulations.

    Science.gov (United States)

    Fávero-Retto, Maely P; Palmieri, Leonardo C; Souza, Tatiana A C B; Almeida, Fábio C L; Lima, Luís Mauricio T R

    2013-11-01

    We have studied regular acting, wild-type human insulin at potency of 100 U/mL from four different pharmaceutical products directly from their final finished formulation by the combined use of mass spectrometry (MS), dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), nuclear magnetic resonance (NMR), and single-crystal protein crystallography (PX). All products showed similar oligomeric assembly in solution as judged by DLS and SAXS measurements. The NMR spectra were compatible with well folded proteins, showing close conformational identity for the human insulin in the four products. Crystallographic assays conducted with the final formulated products resulted in all insulin crystals belonging to the R3 space group with two a dimer in the asymmetric unit, both with the B-chain in the T configuration. Meta-analysis of the 24 crystal structures solved from the four distinct insulin products revealed close similarity between them regardless of variables such as biological origin, product batch, country origin of the product, and analytical approach, revealing a low conformational variability for the converging insulin structural ensemble. We propose the use of MS, SAXS, NMR fingerprint, and PX as a precise chemical and structural proof of folding identity of regular insulin in the final, formulated product.

  6. Human umbilical cord-derived mesenchymal stem cells can secrete insulin in vitro and in vivo.

    Science.gov (United States)

    Boroujeni, Zahra Niki; Aleyasin, Ahmad

    2014-01-01

    Diabetes mellitus is characterized by autoimmune destruction of pancreatic beta cells, leading to decreased insulin production. Differentiation of mesenchymal stem cells (MSCs) into insulin-producing cells offers novel ways of diabetes treatment. MSCs can be isolated from the human umbilical cord tissue and differentiate into insulin-secreting cells. Human umbilical cord-derived stem cells (hUDSCs) were obtained after birth, selected by plastic adhesion, and characterized by flow cytometric analysis. hUDSCs were transduced with nonintegrated lentivirus harboring PDX1 (nonintegrated LV-PDX1) and was cultured in differentiation medium in 21 days. Pancreatic duodenum homeobox protein-1 (PDX1) is a transcription factor in pancreatic development. Significant expressions of PDX1, neurogenin3 (Ngn3), glucagon, glucose transporter2 (Glut2), and somatostatin were detected by quantitative RT-PCR (P insulin proteins were shown by immunocytochemistry analysis. Insulin secretion of hUDSCs(PDX1+) in the high-glucose medium was 1.8 μU/mL. They were used for treatment of diabetic rats and could decrease the blood glucose level from 400 mg/dL to a normal level in 4 days. In conclusion, our results demonstrated that hUDSCs are able to differentiate into insulin-producing cells by transduction with nonintegrated LV-PDX1. These hUDSCs(PDX1+) have the potential to be used as a viable resource in cell-based gene therapy of type 1 diabetes.

  7. Validation of methods for measurement of insulin secretion in humans in vivo

    DEFF Research Database (Denmark)

    Kjems, L L; Christiansen, E; Vølund, A;

    2000-01-01

    of these mathematical techniques for quantification of insulin secretion have been tested in dogs, but not in humans. In the present studies, we examined the validity of both methods to recover the known infusion rates of insulin and C-peptide mimicking ISR during an oral glucose tolerance test. ISR from both......To detect and understand the changes in beta-cell function in the pathogenesis of type 2 diabetes, an accurate and precise estimation of prehepatic insulin secretion rate (ISR) is essential. There are two common methods to assess ISR, the deconvolution method (by Eaton and Polonsky......)-considered the "gold standard"-and the combined model (by Vølund et al.). The deconvolution method is a 2-day method, which generally requires separate assessment of C-peptide kinetics, whereas the combined model is a single-day method that uses insulin and C-peptide data from a single test of interest. The validity...

  8. Insulin resistance and the mitochondrial link. Lessons from cultured human myotubes

    DEFF Research Database (Denmark)

    Gaster, Michael

    2007-01-01

    In order to better understand the impact of reduced mitochondrial function for the development of insulin resistance and cellular metabolism, human myotubes were established from lean, obese, and T2D subjects and exposed to mitochondrial inhibitors, either affecting the electron transport chain...... lipid uptake. The metabolic phenotype during respiratory uncoupling resembled the above picture, except for an increase in glucose and palmitate oxidation. Antimycin A and oligomycin treatment induced insulin resistance at the level of glucose and palmitate uptake in all three study groups while......, at the level of glycogen synthesis, insulin resistance was only seen in lean myotubes. Primary insulin resistance in diabetic myotubes was significantly worsened at the level of glucose and lipid uptake. The present study is the first convincing data linking functional mitochondrial impairment per se...

  9. Glucose-dependent insulinotropic polypeptide induces cytokine expression, lipolysis, and insulin resistance in human adipocytes.

    Science.gov (United States)

    Timper, Katharina; Grisouard, Jean; Sauter, Nadine S; Herzog-Radimerski, Tanja; Dembinski, Kaethi; Peterli, Ralph; Frey, Daniel M; Zulewski, Henryk; Keller, Ulrich; Müller, Beat; Christ-Crain, Mirjam

    2013-01-01

    Obesity-related insulin resistance is linked to a chronic state of systemic and adipose tissue-derived inflammation. Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone also acting on adipocytes. We investigated whether GIP affects inflammation, lipolysis, and insulin resistance in human adipocytes. Human subcutaneous preadipocyte-derived adipocytes, differentiated in vitro, were treated with human GIP to analyze mRNA expression and protein secretion of cytokines, glycerol, and free fatty acid release and insulin-induced glucose uptake. GIP induced mRNA expression of IL-6, IL-1β, and the IL-1 receptor antagonist IL-1Ra, whereas TNFα, IL-8, and monocyte chemotactic protein (MCP)-1 remained unchanged. Cytokine induction involved PKA and the NF-κB pathway as well as an autocrine IL-1 effect. Furthermore, GIP potentiated IL-6 and IL-1Ra secretion in the presence of LPS, IL-1β, and TNFα. GIP induced lipolysis via activation of hormone-sensitive lipase and was linked to NF-κB activation. Finally, chronic GIP treatment impaired insulin-induced glucose uptake possibly due to the observed impaired translocation of glucose transporter GLUT4. In conclusion, GIP induces an inflammatory and prolipolytic response via the PKA -NF-κB-IL-1 pathway and impairs insulin sensitivity of glucose uptake in human adipocytes.

  10. Glucuronidation of edaravone by human liver and kidney microsomes: biphasic kinetics and identification of UGT1A9 as the major UDP-glucuronosyltransferase isoform.

    Science.gov (United States)

    Ma, Liping; Sun, Jianguo; Peng, Ying; Zhang, Rong; Shao, Feng; Hu, Xiaoling; Zhu, Jianping; Wang, Xiaojin; Cheng, Xuefang; Zhu, Yinci; Wan, Ping; Feng, Dong; Wu, Hui; Wang, Guangji

    2012-04-01

    Edaravone was launched in Japan in 2001 and was the first neuroprotectant developed for the treatment of acute cerebral infarction. Edaravone is mainly eliminated as glucuronide conjugate in human urine (approximately 70%), but the mechanism involved in the elimination pathway remains unidentified. We investigated the glucuronidation of edaravone in human liver microsomes (HLM) and human kidney microsomes (HKM) and identified the major hepatic and renal UDP-glucuronosyltransferases (UGTs) involved. As we observed, edaravone glucuronidation in HLM and HKM exhibited biphasic kinetics. The intrinsic clearance of glucuronidation at high-affinity phase (CL(int1)) and low-affinity phase (CL(int2)) were 8.4 ± 3.3 and 1.3 ± 0.2 μl · min(-1) · mg(-1), respectively, for HLM and were 45.3 ± 8.2 and 1.8 ± 0.1 μl · min(-1) · mg(-1), respectively, for HKM. However, in microsomal incubations contained with 2% bovine serum albumin, CL(int1) and CL(int2) were 16.4 ± 1.2 and 3.7 ± 0.3 μl · min(-1) · mg(-1), respectively, for HLM and were 78.5 ± 3.9 and 3.6 ± 0.5 μl · min(-1) · mg(-1), respectively, for HKM. Screening with 12 recombinant UGTs indicated that eight UGTs (UGT1A1, UGT1A6, UGT1A7, UGT1A8, UGT1A9, UGT1A10, UGT2B7, and UGT2B17) produced a significant amount of glucuronide metabolite. Thus, six UGTs (UGT1A1, UGT1A6, UGT1A7, UGT1A9, UGT2B7, and UGT2B17) expressed in human liver or kidney were selected for kinetic studies. Among them, UGT1A9 exhibited the highest activity (CL(int1) = 42.4 ± 9.5 μl · min(-1) · mg(-1)), followed by UGT2B17 (CL(int) = 3.3 ± 0.4 μl · min(-1) · mg(-1)) and UGT1A7 (CL(int) = 1.7 ± 0.2 μl · min(-1) · mg(-1)). Inhibition study found that inhibitor of UGT1A9 (propofol) attenuated edaravone glucuronidation in HLM and HKM. In addition, edaravone glucuronidation in a panel of seven HLM was significantly correlated (r = 0.9340, p = 0.0021) with propofol glucuronidation. Results indicated that UGT1A9 was the main UGT isoform

  11. Caenorhabditis elegans DAF-2 as a Model for Human Insulin Receptoropathies

    Directory of Open Access Journals (Sweden)

    David A. Bulger

    2017-01-01

    Full Text Available Human exome sequencing has dramatically increased the rate of identification of disease-associated polymorphisms. However, examining the functional consequences of those variants has created an analytic bottleneck. Insulin-like signaling in Caenorhabditis elegans has long provided a model to assess consequences of human insulin signaling mutations, but this has not been evaluated in the context of current genetic tools. We have exploited strains derived from the Million Mutation Project (MMP and gene editing to explore further the evolutionary relationships and conservation between the human and C. elegans insulin receptors. Of 40 MMP alleles analyzed in the C. elegans insulin-like receptor gene DAF-2, 35 exhibited insulin-like signaling indistinguishable from wild-type animals, indicating tolerated mutations. Five MMP alleles proved to be novel dauer-enhancing mutations, including one new allele in the previously uncharacterized C-terminus of DAF-2. CRISPR-Cas9 genome editing was used to confirm the phenotypic consequence of six of these DAF-2 mutations and to replicate an allelic series of known human disease mutations in a highly conserved tyrosine kinase active site residue, demonstrating the utility of C. elegans for directly modeling human disease. Our results illustrate the challenges associated with prediction of the phenotypic consequences of amino acid substitutions, the value of assaying mutant isoform function in vivo, and how recently developed tools and resources afford the opportunity to expand our understanding even of highly conserved regulatory modules such as insulin signaling. This approach may prove generally useful for modeling phenotypic consequences of candidate human pathogenic mutations in conserved signaling and developmental pathways.

  12. Effect of insulin catheter wear-time on subcutaneous adipose tissue blood flow and insulin absorption in humans

    DEFF Research Database (Denmark)

    Clausen, Trine Schnedler; Kaastrup, Peter; Stallknecht, Bente

    2009-01-01

    blood flow (ATBF) and absorption of the rapid-acting insulin analog insulin aspart over a period of 4 days. METHODS: Teflon insulin catheters (Medtronic, Minneapolis, MN) were inserted into the abdominal SAT of 10 healthy men without diabetes (mean +/- SEM age, 23.0 +/- 1.1 years; body mass index, 22...... +/- 3 min on day 0 to 45 +/- 4 min on day 4 (P = 0.019). Neither peak plasma concentration nor area under the curve of insulin aspart changed significantly. CONCLUSIONS: Insertion of a Teflon insulin catheter into the SAT results in increased ATBF and faster absorption of insulin aspart in a period of 4...

  13. Simultaneous determination and validated quantification of human insulin and its synthetic analogues in human blood serum by immunoaffinity purification and liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Hess, Cornelius; Thomas, Andreas; Thevis, Mario; Stratmann, Bernd; Quester, Wulf; Tschoepe, Diethelm; Madea, Burkhard; Musshoff, Frank

    2012-10-01

    Possible fatal complications of human insulin and its synthetic analogues like hypoglycemia require precise classification and quantitative determination of these drugs both for clinical purposes as well as for forensic toxicologists. A procedure was developed for the identification and quantification of human insulin and different long-acting as well as short-acting synthetic insulins in human blood serum specimens. After an immunoaffinity purification step and separation by liquid chromatography, the insulins were characterized by their five- or sixfold protonated molecule ions and diagnostic product ions. Clinical samples of 207 diabetic and 50 non-diabetic patients after the administration of human insulin or oral antidiabetics and forensic samples were analyzed for human/synthetic insulin concentrations. The method was validated according to international guidelines. Limits of detection of the insulins ranged between 1.3 and 2.8 μU/ml. Recoveries ranged between 33.2 % and 51.7 %. Precision data was in accordance with international guidelines. Clinical samples showed concentrations of human insulin lower than 301 μU/ml. Our liquid chromatography tandem mass spectrometry procedure allows unambiguous identification and quantification of the intact human insulin and its intact synthetic analogues Humalog®, Novolog®, Apidra®, Lantus®, and Levemir® in human blood serum in clinical and overdose cases. The assay could be successfully tested in patients with diabetes mellitus on therapy with insulins or oral antidiabetics.

  14. Reversal of diabetes with insulin-producing cells derived in vitro from human pluripotent stem cells.

    Science.gov (United States)

    Rezania, Alireza; Bruin, Jennifer E; Arora, Payal; Rubin, Allison; Batushansky, Irina; Asadi, Ali; O'Dwyer, Shannon; Quiskamp, Nina; Mojibian, Majid; Albrecht, Tobias; Yang, Yu Hsuan Carol; Johnson, James D; Kieffer, Timothy J

    2014-11-01

    Transplantation of pancreatic progenitors or insulin-secreting cells derived from human embryonic stem cells (hESCs) has been proposed as a therapy for diabetes. We describe a seven-stage protocol that efficiently converts hESCs into insulin-producing cells. Stage (S) 7 cells expressed key markers of mature pancreatic beta cells, including MAFA, and displayed glucose-stimulated insulin secretion similar to that of human islets during static incubations in vitro. Additional characterization using single-cell imaging and dynamic glucose stimulation assays revealed similarities but also notable differences between S7 insulin-secreting cells and primary human beta cells. Nevertheless, S7 cells rapidly reversed diabetes in mice within 40 days, roughly four times faster than pancreatic progenitors. Therefore, although S7 cells are not fully equivalent to mature beta cells, their capacity for glucose-responsive insulin secretion and rapid reversal of diabetes in vivo makes them a promising alternative to pancreatic progenitor cells or cadaveric islets for the treatment of diabetes.

  15. Acute and chronic effects of glyceryl trinitrate therapy on insulin and glucose regulation in humans.

    Science.gov (United States)

    Jedrzkiewicz, Sean; Parker, John D

    2013-05-01

    This study examined the effect of acute and sustained transdermal glyceryl trinitrate (GTN) therapy on insulin and glucose regulation. Totally, 12 males (18-30 years) underwent a glucose tolerance test at baseline (visit 1), 90 minutes after acute transdermal GTN 0.6 mg/h (visit 2), following 7 days of continuous GTN (visit 3), and 2 to 3 days after stopping GTN (visit 4). At each visit, plasma glucose and insulin concentrations were measured before and 30, 60, 90, and 120 minutes after a 75-g oral glucose load. Indices of glucose metabolism that were examined included the insulin sensitivity index, the homeostasis model assessment of insulin resistance (HOMA-IR), and the insulinogenic index. The acute administration of GTN had no effect on glucose and insulin responses (visit 2). However, after 7 days of GTN exposure (visit 3) there was an increase in the mean glucose concentration measured after the oral glucose load. On visit 1, the mean glucose concentration (± standard deviation) following the 75 g oral glucose challenge was 5.7 ± 0.5 µmol/L. On visit 3, after 7 days of transdermal GTN therapy, the mean glucose concentration after the oral glucose was significantly higher; 6.2 ± 0.5 µmol/L (P GTN therapy modifies glucose metabolism causing evidence of increased insulin resistance during sustained therapy in normal humans.

  16. Cavitation-enhanced delivery of insulin in agar and porcine models of human skin.

    Science.gov (United States)

    Feiszthuber, Helga; Bhatnagar, Sunali; Gyöngy, Miklós; Coussios, Constantin-C

    2015-03-21

    Ultrasound-assisted transdermal insulin delivery offers a less painful and less invasive alternative to subcutaneous insulin injections. However, ultrasound-based drug delivery, otherwise known as sonophoresis, is a highly variable phenomenon, in part dependent on cavitation. The aim of the current work is to investigate the role of cavitation in transdermal insulin delivery. Fluorescently stained, soluble Actrapid insulin was placed on the surface of human skin-mimicking materials subjected to 265 kHz, 10% duty cycle focused ultrasound. A confocally and coaxially aligned 5 MHz broadband ultrasound transducer was used to detect cavitation. Two different skin models were used. The first model, 3% agar hydrogel, was insonated with a range of pressures (0.25-1.40 MPa peak rarefactional focal pressure-PRFP), with and without cavitation nuclei embedded within the agar at a concentration of 0.05% w/v. The second, porcine skin was insonated at 1.00 and 1.40 MPa PRFP. In both models, fluorescence measurements were used to determine penetration depth and concentration of delivered insulin. Results show that in agar gel, both insulin penetration depth and concentration only increased significantly in the presence of inertial cavitation, with up to a 40% enhancement. In porcine skin the amount of fluorescent insulin was higher in the epidermis of those samples that were exposed to ultrasound compared to the control samples, but there was no significant increase in penetration distance. The results underline the importance of instigating and monitoring inertial cavitation during transdermal insulin delivery.

  17. Insulin increases phosphorylation of mitochondrial proteins in human skeletal muscle in vivo

    DEFF Research Database (Denmark)

    Zhao, Xiaolu; Bak, Steffen; Pedersen, Andreas James Thestrup;

    2014-01-01

    There is increasing evidence that multiple proteins involved in key regulatory processes in mitochondria are phosphorylated in mammalian tissues. Insulin regulates glucose metabolism by phosphorylation-dependent signaling and has been shown to stimulate ATP synthesis in human skeletal muscle. Here...... the majority of novel sites. Phosphorylation sites detected more often or exclusively in insulin-stimulated samples include multiple sites in mitochondrial proteins involved in oxidative phosphorylation, tricarboxylic acid cycle, and fatty acid metabolism, as well as several components of the newly defined......, we investigated the effect of insulin on the phosphorylation of mitochondrial proteins in human skeletal muscle in vivo. Using a combination of TiO2 phosphopeptide-enrichment, HILIC fractionation, and LC−MS/MS, we compared the phosphoproteomes of isolated mitochondria from skeletal muscle samples...

  18. PKCδ regulates hepatic insulin sensitivity and hepatosteatosis in mice and humans

    DEFF Research Database (Denmark)

    Bezy, Olivier; Tran, Thien T; Pihlajamäki, Jussi;

    2011-01-01

    PKCδ. Here, we found that PKCδ expression in liver was 2-fold higher in B6 versus 129 mice from birth and was further increased in B6 but not 129 mice in response to a high-fat diet. PRKCD gene expression was also elevated in obese humans and was positively correlated with fasting glucose...... tolerance, and reduced hepatosteatosis with aging. Conversely, mice with liver-specific overexpression of PKCδ developed hepatic insulin resistance characterized by decreased insulin signaling, enhanced lipogenic gene expression, and hepatosteatosis. Therefore, changes in the expression and regulation...... of PKCδ between strains of mice and in obese humans play an important role in the genetic risk of hepatic insulin resistance, glucose intolerance, and hepatosteatosis; and thus PKCδ may be a potential target in the treatment of metabolic syndrome....

  19. The accumulations of HIF-1α and HIF-2α by JNK and ERK are involved in biphasic effects induced by different levels of arsenite in human bronchial epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yuan; Li, Yuan [Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 210029, Jiangsu (China); The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 210029, Jiangsu (China); Li, Huiqiao [Qujing Center for Disease Control and Prevention, Qujing 655000, Yunnan (China); Pang, Ying; Zhao, Yue; Jiang, Rongrong; Shen, Lu [Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 210029, Jiangsu (China); The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 210029, Jiangsu (China); Zhou, Jianwei; Wang, Xinru [The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 210029, Jiangsu (China); Liu, Qizhan, E-mail: drqzliu@hotmail.com [Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 210029, Jiangsu (China); The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 210029, Jiangsu (China)

    2013-01-15

    The biphasic effects of arsenite, in which low levels of arsenite induce cell proliferation and high levels of arsenite induce DNA damage and apoptosis, apparently contribute to arsenite-induced carcinogenesis. However, the mechanisms underlying this phenomenon are not well understood. In this study, we investigated the effects of different levels of arsenite on cell proliferation, DNA damage and apoptosis as well as on signal transduction pathways in human bronchial epithelial (HBE) cells. Our results show that a low level of arsenite activates extracellular signal-regulated kinases (ERK), which probably mediate arsenite-inhibited degradation of ubiquitinated hypoxia-inducible factor-2α (HIF-2α) in HBE cells. ERK inhibition blocks cell proliferation induced by a low level of arsenite, in part via HIF-2α. In contrast, a high level of arsenite activates c-Jun N-terminal kinases (JNK), which provoke a response to suppress ubiquitinated HIF-1α degradation. Down-regulation of HIF-1α by inhibiting JNK, however, increases the DNA damage but decreases the apoptosis induced by a high level of arsenite. Thus, data in the present study suggest that the accumulations of HIF-1α and HIF-2α by JNK and ERK are involved in different levels of arsenite-induced biphasic effects, with low levels of arsenite inducing cell proliferation and high levels of arsenite inducing DNA damage and apoptosis in HBE cells. -- Highlights: ► Biphasic effects induced by different concentrations of arsenite. ► Different regulation of ERK or JNK signal pathway by arsenite. ► Different regulation of HIF1α or HIF 2α by arsenite.

  20. Effect of 5'-flanking sequence deletions on expression of the human insulin gene in transgenic mice

    DEFF Research Database (Denmark)

    Fromont-Racine, M; Bucchini, D; Madsen, O;

    1990-01-01

    Expression of the human insulin gene was examined in transgenic mouse lines carrying the gene with various lengths of DNA sequences 5' to the transcription start site (+1). Expression of the transgene was demonstrated by 1) the presence of human C-peptide in urine, 2) the presence of specific tra...... of the transgene was observed in cell types other than beta-islet cells.......Expression of the human insulin gene was examined in transgenic mouse lines carrying the gene with various lengths of DNA sequences 5' to the transcription start site (+1). Expression of the transgene was demonstrated by 1) the presence of human C-peptide in urine, 2) the presence of specific......, and -168 allowed correct initiation of the transcripts and cell specificity of expression, while quantitative expression gradually decreased. Deletion to -58 completely abolished the expression of the gene. The amount of human product that in mice harboring the longest fragment contributes up to 50...

  1. Biphasic Polyurethane/Polylactide Sponges Doped with Nano-Hydroxyapatite (nHAp Combined with Human Adipose-Derived Mesenchymal Stromal Stem Cells for Regenerative Medicine Applications

    Directory of Open Access Journals (Sweden)

    Krzysztof Marycz

    2016-10-01

    Full Text Available Cartilage and bone tissue injuries are common targets in regenerative medicine. The degeneration of cartilage tissue results in tissue loss with a limited ability to regenerate. However, the application of mesenchymal stem cells in the course of such condition makes it possible to manage this disorder by improving the structure of the remaining tissue and even stimulating its regeneration. Nevertheless, in the case of significant tissue loss, standard local injection of cell suspensions is insufficient, due to the low engraftment of transplanted cells. Introduction of mesenchymal stem cells on the surface of a compatible biomaterial can be a promising tool for inducing the regeneration by both retaining the cells at the desired site and filling the tissue gap. In order to obtain such a cell-biomaterial hybrid, we developed complex, biphasic polymer blend biomaterials composed of various polyurethane (PU-to-polylactide (PLA ratios, and doped with different concentrations of nano-hydroxyapatite (nHAp. We have determined the optimal blend composition and nano-hydroxyapatite concentration for adipose mesenchymal stem cells cultured on the biomaterial. We applied biological in vitro techniques, including cell viability assay, determination of oxidative stress factors level, osteogenic and chondrogenic differentiation potentials as well as cell proteomic analysis. We have shown that the optimal composition of biphasic scaffold was 20:80 of PU:PLA with 20% of nHAp for osteogenic differentiation, and 80:20 of PU:PLA with 10% of nHAp for chondrogenic differentiation, which suggest the optimal composition of final biphasic implant for regenerative medicine applications.

  2. Human pituitary and placental hormones control human insulin-like growth factor II secretion in human granulosa cells

    Energy Technology Data Exchange (ETDEWEB)

    Ramasharma, K.; Li, C.H.

    1987-05-01

    Human granulosa cells cultured with calf serum actively proliferated for 18-20 generations and secreted progesterone into the medium; progesterone levels appeared to decline with increase in generation number. Cells cultured under serum-free conditions secreted significant amounts of progesterone and insulin-like growth factor II (IGF-II). The progesterone secretion was enhanced by the addition of human follitropin, lutropin, and chorionic gonadotropin but not by growth hormone. These cells, when challenged to varying concentrations of human growth hormone, human chorionic somatomammotropin, human prolactin, chorionic gonadotropin, follitropin, and lutropin, secreted IGF-II into the medium as measured by specific IGF-II RIA. Among these human hormones, chorionic gonadotropin, follitropin, and lutropin were most effective in inducing IGF-II secretion from these cells. When synthetic lutropin-releasing hormone and ..cap alpha..-inhibin-92 were tested, only lutropin-releasing hormone was effective in releasing IGF-II. The results described suggest that cultured human granulosa cells can proliferate and actively secrete progesterone and IGF-II into the medium. IGF-II production in human granulosa cells was influenced by a multi-hormonal complex including human growth hormone, human chorionic somatomammotropin, and prolactin.

  3. A sensitive chemiluminescent enzyme immunoassay for the bioanalysis of carboxyl-terminal B-chain analogues of human insulin.

    Science.gov (United States)

    Cao, Y; Smith, W C; Bowsher, R R

    2001-08-01

    Quantification of analogues of human insulin in biological matrices is complicated by differences in their immunoreactivity and the presence of both the analogue and endogenous concentrations of insulin in test samples. To facilitate pharmacokinetic comparisons of carboxyl-terminal B-chain analogues of human insulin, we undertook development of a sensitive ELISA. The ELISA detection method was optimized systematically to permit routine analysis of 10-microl serum samples. Accordingly, a noncompetitive 'sandwich' chemiluminescent ELISA was validated for the quantification of carboxyl-terminal B-chain insulin analogues in human serum over a concentration range from 5 to 3125 pM. The mean bias (RE%) within the validated range varied from -10.3 to 4.3%, with an intermediate precision (inter-assay CV%) from 4.2 to 11.5%. The two-sided 90% expectation tolerance interval for total measurement error was within +/-25% of the nominal concentration for all levels of validation samples. Insulin lispro, human insulin, proinsulin, despentapeptide insulin (DPI) and porcine insulin displayed comparable crossreactivity in the ELISA. Potential utility of the new assay for insulin bioanalysis in nonhuman species was investigated by assessing the pharmacokinetic profile of DPI in rats following administration of a single subcutaneous dose. The sensitive chemiluminescent detection method is simple to perform and should be readily adaptable for ELISAs of other therapeutic proteins.

  4. Oral insulin (human, murine, or porcine) does not prevent diabetes in the non-obese diabetic mouse.

    Science.gov (United States)

    Pham, Minh N; Gibson, Claire; Rydén, Anna K E; Perdue, Nikole; Boursalian, Tamar E; Pagni, Philippe P; Coppieters, Ken; Skonberg, Christian; Porsgaard, Trine; von Herrath, Matthias; Vela, Jose Luis

    2016-03-01

    Studies have shown oral insulin prevents type 1 diabetes (T1D) in mouse models, however human trials were inconclusive. We tested the ability of different insulins to prevent T1D in non-obese diabetic mice. Mice received oral insulin or PBS twice weekly and disease was monitored. Contrary to previous studies, no insulin tested showed significant ability to prevent T1D, nor did testing of linked suppression in a delayed type hypersensitivity model have reproducible effect. To investigate delivery of antigen within the GI tract, blue dye was fed to mice. Dye traveled 5-8 cm from stomach to small intestine within 10s, suggesting orally administered antigen may not get digested in the stomach in mice. Insulin incubated with jejunum extracts was instantly digested. Thus, in humans large doses of insulin may be required to achieve tolerance as antigen may be more vulnerable to digestion in the stomach even before reaching the small intestine.

  5. Gene therapy for type 1 diabetes mellitus in rats by gastrointestinal administration of chitosan nanoparticles containing human insulin gene

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    AIM: To study the expression of human insulin gene in gastrointestinal tracts of diabetic rats. METHODS: pCHV.Ins, an expression plasmid of the human insulin gene, wrapped with chitosan nanoparticles, was transfected to the diabetic rats through lavage and coloclysis, respectively. Fasting blood glucose and plasma insulin levels were measured for 7 d. Reverse transcription polymerase chain reaction (RT-PCR) analysis and Western blot analysis were performed to confirm the expression of human insulin gene. RESULTS: Compared with the control group, the fasting blood glucose levels in the lavage and coloclysis groups were decreased significantly in 4 d (5.63 ± 0.48 mmol/L and 5.07 ± 0.37 mmol/L vs 22.12± 1.31 mmol/L, respectively, P < 0.01), while the plasma insulin levels were much higher (32.26±1.81 μIU/mL and 32.79 ± 1.84 μIU/mL vs 14.23 ± 1.38 μIU/mL, respectively, P<0.01). The human insulin gene mRNA and human insulin were only detected in the lavage and coloclysis groups. CONCLUSION: Human insulin gene wrapped with chitosan nanoparticles can be successfully transfected to rats through gastrointestinal tract, indicating that chitosan is a promising non-viral vector.

  6. Insulin and GH Signaling in Human Skeletal Muscle In Vivo following Exogenous GH Exposure: Impact of an Oral Glucose Load

    OpenAIRE

    Thomas Krusenstjerna-Hafstrøm; Michael Madsen; Vendelbo, Mikkel H.; Pedersen, Steen B.; Christiansen, Jens S.; Niels Møller; Niels Jessen; Jørgensen, Jens O.L.

    2011-01-01

    INTRODUCTION: GH induces acute insulin resistance in skeletal muscle in vivo, which in rodent models has been attributed to crosstalk between GH and insulin signaling pathways. Our objective was to characterize time course changes in signaling pathways for GH and insulin in human skeletal muscle in vivo following GH exposure in the presence and absence of an oral glucose load. METHODS: Eight young men were studied in a single-blinded randomized crossover design on 3 occasions: 1) after an int...

  7. Effect of phorbol and glucose on insulin secretion from the human fetal pancreas.

    Science.gov (United States)

    Tuch, B E; Williams, P F; Handelsman, D; Dunlop, M; Grigoriou, S; Turtle, J R

    1987-04-01

    It has been reported previously that 12-0-tetradecanoylphorbol-13-acetate is capable of stimulating the release of insulin from adult and neonatal pancreatic tissue. The data from this study show that this agent at a concentration of 1.3 uM, in the presence of 2.8 mM glucose, was unable to cause significant secretion of insulin from cultured human fetal pancreatic explants. By contrast 20 mM glucose was able to cause a small but significant immediate increase in secretion of insulin, but was unable to maintain this response beyond ten minutes. When the two agents were combined, a synergistic effect was seen throughout the entire 50 minute period of stimulation. The reason for this synergism is unclear since, whilst both secretagogues were able to cause a rise in the levels of diacylglycerol, together no extra effect was observed.

  8. Seven mutations in the human insulin gene linked to permanent neonatal/infancy-onset diabetes mellitus

    DEFF Research Database (Denmark)

    Colombo, Carlo; Porzio, Ottavia; Liu, Ming;

    2008-01-01

    Permanent neonatal diabetes mellitus (PNDM) is a rare disorder usually presenting within 6 months of birth. Although several genes have been linked to this disorder, in almost half the cases documented in Italy, the genetic cause remains unknown. Because the Akita mouse bearing a mutation...... in the Ins2 gene exhibits PNDM associated with pancreatic beta cell apoptosis, we sequenced the human insulin gene in PNDM subjects with unidentified mutations. We discovered 7 heterozygous mutations in 10 unrelated probands. In 8 of these patients, insulin secretion was detectable at diabetes onset...... of endoplasmic reticulum stress, and with increased apoptosis. Similarly transfected INS-1E insulinoma cells had diminished viability compared with those expressing WT proinsulin. In conclusion, we find that mutations in the insulin gene that promote proinsulin misfolding may cause PNDM....

  9. Human insulin polymorphism upon ligand binding and pH variation: the case of 4-ethylresorcinol

    Directory of Open Access Journals (Sweden)

    S. Fili

    2015-09-01

    Full Text Available This study focuses on the effects of the organic ligand 4-ethylresorcinol on the crystal structure of human insulin using powder X-ray crystallography. For this purpose, systematic crystallization experiments have been conducted in the presence of the organic ligand and zinc ions within the pH range 4.50–8.20, while observing crystallization behaviour around the isoelectric point of insulin. High-throughput crystal screening was performed using a laboratory X-ray diffraction system. The most representative samples were selected for synchrotron X-ray diffraction measurements, which took place at the European Synchrotron Radiation Facility (ESRF and the Swiss Light Source (SLS. Four different crystalline polymorphs have been identified. Among these, two new phases with monoclinic symmetry have been found, which are targets for the future development of microcrystalline insulin drugs.

  10. Effect of training on insulin sensitivity of glucose uptake and lipolysis in human adipose tissue

    DEFF Research Database (Denmark)

    Stallknecht, Bente; Larsen, J J; Mikines, K J;

    2000-01-01

    Training increases insulin sensitivity of both whole body and muscle in humans. To investigate whether training also increases insulin sensitivity of adipose tissue, we performed a three-step hyperinsulinemic, euglycemic clamp in eight endurance-trained (T) and eight sedentary (S) young men...... [insulin infusion rates: 10,000 (step I), 20,000 (step II), and 150,000 (step III) microU x min(-1) x m(-2)]. Glucose and glycerol concentrations were measured in arterial blood and also by microdialysis in interstitial fluid in periumbilical, subcutaneous adipose tissue and in quadriceps femoris muscle...... (glucose only). Adipose tissue blood flow was measured by (133)Xe washout. In the basal state, adipose tissue blood flow tended to be higher in T compared with S subjects, and in both groups blood flow was constant during the clamp. The change from basal in arterial-interstitial glucose concentration...

  11. Validation of methods for measurement of insulin secretion in humans in vivo

    DEFF Research Database (Denmark)

    Kjems, L L; Christiansen, E; Vølund, A;

    2000-01-01

    To detect and understand the changes in beta-cell function in the pathogenesis of type 2 diabetes, an accurate and precise estimation of prehepatic insulin secretion rate (ISR) is essential. There are two common methods to assess ISR, the deconvolution method (by Eaton and Polonsky...... of these mathematical techniques for quantification of insulin secretion have been tested in dogs, but not in humans. In the present studies, we examined the validity of both methods to recover the known infusion rates of insulin and C-peptide mimicking ISR during an oral glucose tolerance test. ISR from both...... the combined model and the deconvolution method were accurate, i.e., recovery of true ISR was not significantly different from 100%. Furthermore, both maximal and total ISRs from the combined model were strongly correlated to those obtained by the deconvolution method (r = 0.89 and r = 0.82, respectively...

  12. A novel Gymnema sylvestre extract stimulates insulin secretion from human islets in vivo and in vitro.

    Science.gov (United States)

    Al-Romaiyan, A; Liu, B; Asare-Anane, H; Maity, C R; Chatterjee, S K; Koley, N; Biswas, T; Chatterji, A K; Huang, G-C; Amiel, S A; Persaud, S J; Jones, P M

    2010-09-01

    Many plant-based products have been suggested as potential antidiabetic agents, but few have been shown to be effective in treating the symptoms of Type 2 diabetes mellitus (T2DM) in human studies, and little is known of their mechanisms of action. Extracts of Gymnema sylvestre (GS) have been used for the treatment of T2DM in India for centuries. The effects of a novel high molecular weight GS extract, Om Santal Adivasi, (OSA(R)) on plasma insulin, C-peptide and glucose in a small cohort of patients with T2DM are reported here. Oral administration of OSA(R) (1 g/day, 60 days) induced significant increases in circulating insulin and C-peptide, which were associated with significant reductions in fasting and post-prandial blood glucose. In vitro measurements using isolated human islets of Langerhans demonstrated direct stimulatory effects of OSA(R) on insulin secretion from human ß-cells, consistent with an in vivo mode of action through enhancing insulin secretion. These in vivo and in vitro observations suggest that OSA(R) may provide a potential alternative therapy for the hyperglycemia associated with T2DM.

  13. RFX6 Regulates Insulin Secretion by Modulating Ca2+ Homeostasis in Human β Cells

    Directory of Open Access Journals (Sweden)

    Vikash Chandra

    2014-12-01

    Full Text Available Development and function of pancreatic β cells involve the regulated activity of specific transcription factors. RFX6 is a transcription factor essential for mouse β cell differentiation that is mutated in monogenic forms of neonatal diabetes. However, the expression and functional roles of RFX6 in human β cells, especially in pathophysiological conditions, are poorly explored. We demonstrate the presence of RFX6 in adult human pancreatic endocrine cells. Using the recently developed human β cell line EndoC-βH2, we show that RFX6 regulates insulin gene transcription, insulin content, and secretion. Knockdown of RFX6 causes downregulation of Ca2+-channel genes resulting in the reduction in L-type Ca2+-channel activity that leads to suppression of depolarization-evoked insulin exocytosis. We also describe a previously unreported homozygous missense RFX6 mutation (p.V506G that is associated with neonatal diabetes, which lacks the capacity to activate the insulin promoter and to increase Ca2+-channel expression. Our data therefore provide insights for understanding certain forms of neonatal diabetes.

  14. Effects of pasteurization on adiponectin and insulin concentrations in donor human milk.

    Science.gov (United States)

    Ley, Sylvia H; Hanley, Anthony J; Stone, Debbie; O'Connor, Deborah L

    2011-09-01

    Although pasteurization is recommended before distributing donor human milk in North America, limited data are available on its impact on metabolic hormones in milk. We aimed to investigate the effects of pasteurization on adiponectin and insulin concentrations in donor human milk. The study investigates concentrations of components in donor human milk before and after Holder pasteurization. After the guidelines of the Human Milk Bank Association of North America, human milk samples were pooled to produce 17 distinct batches (4 individuals per batch) and pasteurized at 62.5°C for 30 min. Adiponectin, insulin, energy, fat, total protein, and glucose concentrations were measured pre- and postpasteurization. Pasteurization reduced milk adiponectin and insulin by 32.8 and 46.1%, respectively (both p milk composition (r = 0.36-0.47; all p milk hormone concentrations remained significant after adjusting for fat and energy (beta ± SEE: -4.11 ± 1.27, p = 0.003 for adiponectin; -70.0 ± 15.0, p human milk. In view of emerging knowledge on the importance of milk components, continued work to find the optimal pasteurization process that mitigates risks but promotes retention of bioactive components is needed.

  15. 双时相门冬胰岛素30每日1次对2型糖尿病患者的疗效和安全性%Efficacy and safety of once-daily biphasic insulin aspart 30 in insulin-na(i)ve patients with type 2 diabetes

    Institute of Scientific and Technical Information of China (English)

    Easy Start Study(ESS)协作组

    2011-01-01

    目的 评价2型糖尿病患者每日1次应用双时相门冬胰岛素30治疗的有效性和安全性.方法 本研究为多中心、开放性、自身对照的临床观察性研究.2008年9月至2009年6月选取未接受降糖治疗或既往口服降糖药治疗血糖控制效果欠佳的2型糖尿病患者621例,平均年龄(56±11)岁,平均糖尿病病程(4.4±4.2)年(0~30年),平均体重指数(25.5±2.9)kg/m2,平均糖化血红蛋白(HbA1c)8.5%±1.2%.使用每日1次双时相门冬胰岛素30,起始剂量和最终剂量分别为(0.16±0.05)U/kg、(0.20±0.07)U/kg.联合口服药治疗12周后评价其有效性和安全性,并探索不同基线因素对于疗效的影响.结果 治疗12周后,HbA1c下降了1.8%±1.1%.HbA1c<6.5%的患者占30.8%,HbA1c<7%的患者占65.5%.空腹血糖和餐后血糖均显著下降,8时点血糖平均值下降了(3.8±2.3)mmol/L.分别按基线糖尿病病程、HbA1c、注射时间和体重指数分层的分析结果显示,HbA1c达标率随着糖尿病病程的延长和HbA1c的升高而降低.在双时相门冬胰岛索30治疗中,非重度低血糖事件每年每例患者的发生率为1.83次.仅有1例(0.2%)患者发生1次重度(夜间)低血糖事件.患者治疗后体重较治疗前显著降低(P=0.0053).结论 在未使用降糖治疗或已用口服降糖药但血糖控制不佳的2型糖尿病患者中,双时相门冬胰岛素30每日1次治疗作为胰岛素起始方案,可安全有效地降低血糖水平,尤其适用于HbA1c水平轻至中度升高,病程相对较短的患者.%Objective To evaluate the efficacy and safety of biphasic insulin aspart 30(BIAsp 30)in the inadequately controlled Chinese patients with type 2 diabetes.Methods Easy Start Study (ESS) was a multi-centre,open-labeled and self-control observational study.From September 2008 to June 2009,a total of 621 insulin-naive patients (pharmacotherapy-na(i)ve patients or patients exposed to oral antidiabetic drugs only) participated in the study

  16. Suspension Culture Alters Insulin Secretion in Induced Human Umbilical Cord Matrix-Derived Mesenchymal Cells

    Directory of Open Access Journals (Sweden)

    Fatemeh Seyedi

    2016-04-01

    Full Text Available Objective: Worldwide, diabetes mellitus (DM is an ever-increasing metabolic disorder. A promising approach to the treatment of DM is the implantation of insulin producing cells (IPC that have been derived from various stem cells. Culture conditions play a pivotal role in the quality and quantity of the differentiated cells. In this experimental study, we have applied various culture conditions to differentiate human umbilical cord matrix-derived mesenchymal cells (hUCMs into IPCs and measured insulin production. Materials and Methods: In this experimental study, we exposed hUCMs cells to pancreatic medium and differentiated them into IPCs in monolayer and suspension cultures. Pancreatic medium consisted of serum-free Dulbecco’s modified eagle’s medium Nutrient mixture F12 (DMEM/F12 medium with 17.5 mM glucose supplemented by 10 mM nicotinamide, 10 nM exendin-4, 10 nM pentagastrin, 100 pM hepatocyte growth factor, and B-27 serum-free supplement. After differentiation, insulin content was analyzed by gene expression, immunocytochemistry (IHC and the chemiluminesence immunoassay (CLIA. Results: Reverse transcription-polymerase chain reaction (RT-PCR showed efficient expressions of NKX2.2, PDX1 and INSULIN genes in both groups. IHC analysis showed higher expression of insulin protein in the hanging drop group, and CLIA revealed a significant higher insulin production in hanging drops compared with the monolayer group following the glucose challenge test. Conclusion: We showed by this novel, simple technique that the suspension culture played an important role in differentiation of hUCMs into IPC. This culture was more efficient than the conventional culture method commonly used in IPC differentiation and cultivation.

  17. Pinitol supplementation does not affect insulin-mediated glucose metabolism and muscle insulin receptor content and phosphorylation in older humans.

    Science.gov (United States)

    Campbell, Wayne W; Haub, Mark D; Fluckey, James D; Ostlund, Richard E; Thyfault, John P; Morse-Carrithers, Hannah; Hulver, Matthew W; Birge, Zonda K

    2004-11-01

    This study assessed the effect of oral pinitol supplementation on oral and intravenous glucose tolerances and on skeletal muscle insulin receptor content and phosphorylation in older people. Fifteen people (6 men, 9 women; age 66 +/- 8 y; BMI 27.9 +/- 3.3 kg/m(2); hemoglobin A1c 5.39 +/- 0.46%, mean +/- SD) completed a 7-wk protocol. Subjects were randomly assigned to groups that during wk 2-7 consumed twice daily either a non-nutritive beverage (Placebo group, n = 8) or the same beverage with 1000 mg pinitol dissolved into it (Pinitol group, n = 7, total dose = 2000 mg pinitol/d). Testing was done at wk 1 and wk 7. In the Pinitol group with supplementation, 24-h urinary pinitol excretion increased 17-fold. The fasting concentrations of glucose, insulin, and C-peptide, and the 180-min area under the curve for these compounds, in response to oral (75 g) and intravenous (300 mg/kg) glucose tolerance challenges, were unchanged from wk 1 to wk 7 and were not influenced by pinitol. Also, pinitol did not affect indices of hepatic and whole-body insulin sensitivity from the oral glucose tolerance test and indices of insulin sensitivity, acute insulin response to glucose, and glucose effectiveness from the intravenous glucose tolerance test, estimated using minimal modeling. Pinitol did not differentially affect total insulin receptor content and insulin receptor phosphotyrosine 1158 and insulin receptor phosphotyrosine 1162/1163 activation in vastus lateralis samples taken during an oral-glucose-induced hyperglycemic and hyperinsulinemic state. These data suggest that pinitol supplementation does not influence whole-body insulin-mediated glucose metabolism and muscle insulin receptor content and phosphorylation in nondiabetic, older people.

  18. Insulin allergy.

    Science.gov (United States)

    Ghazavi, Mohammad K; Johnston, Graham A

    2011-01-01

    Insulin reactions occur rarely but are of tremendous clinical importance. The first was reported in 1922 as a callus reaction at the injection site of insufficiently purified bovine insulin. Porcine insulin was subsequently found to be less allergenic than bovine insulin. Increasingly pure insulins have decreased the risk of adverse reactions, and the production of recombinant insulin with the same amino sequence as human insulin saw a large decrease in adverse reactions. Currently, the prevalence of allergic reactions to insulin products appears to be approximately 2%, and less than one-third of these events have been considered related to the insulin itself. Other reactions occur due to the preservatives added to insulin, including zinc, protamine, and meta-cresol. Allergic reactions can be type I or immunoglobulin E-mediated, type III or Arthus, and type IV or delayed-type hypersensitivity reactions. Type I reactions are the most common and can, rarely, cause anaphylaxis. In contrast, type IV reactions can occur after a delay of several days. Investigations include skin prick testing, patch testing, intradermal testing, and occasionally, skin biopsy.

  19. Variation in the sequence and modification state of the human insulin gene flanking regions.

    Science.gov (United States)

    Ullrich, A; Dull, T J; Gray, A; Philips, J A; Peter, S

    1982-04-10

    The nucleotide sequence of a highly repetitive sequence region upstream from the human insulin gene is reported. The length of this region varies between alleles in the population, and appears to be stably transmitted to the next generation in a Mendelian fashion. There is no significant correlation between the length of this sequence and two types of diabetes mellitus. We observe variation in the cleavability of a BglI recognition site downstream from the human insulin gene, which is probably due to variable nucleotide modification. This presumed modification state appears not to be inherited, and varies between tissues within an individual and between individuals for a given tissue. Both alleles in a given tissue DNA sample are modified to the same extent.

  20. Characterization of lipid metabolism in insulin-sensitive adipocytes differentiated from immortalized human mesenchymal stem cells

    DEFF Research Database (Denmark)

    Prawitt, Janne; Niemeier, Andreas; Kassem, Moustapha

    2008-01-01

    There is a great demand for cell models to study human adipocyte function. Here we describe the adipogenic differentiation of a telomerase-immortalized human mesenchymal stem cell line (hMSC-Tert) that maintains numerous features of terminally differentiated adipocytes even after prolonged......, the presence of the PPARgamma agonist rosiglitazone was not required for the stable expression of lipoprotein lipase, adipocyte fatty acid binding protein and perilipin on mRNA and protein levels. Adiponectin expression was post-transcriptionally down-regulated in the absence of rosiglitazone. Insulin...... sensitivity as measured by insulin-induced phosphorylation of Akt and S6 ribosomal protein was also independent of rosiglitazone. In addition to commonly used adipogenic markers, we investigated further PPARgamma-stimulated proteins with a role in lipid metabolism. We observed an increase of lipoprotein...

  1. Insulin but Not Glucagon Gene is Silenced in Human Pancreas-Derived Mesenchymal Stem Cells

    OpenAIRE

    2009-01-01

    We previously characterized human islet-derived precursor cells (hIPCs) as a specific type of mesenchymal stem cell capable of differentiating to insulin (INS)- and glucagon (GCG)-expressing cells. However, during proliferative expansion, INS transcript becomes undetectable and then cannot be induced, a phenomenon consistent with silencing of the INS gene. We explored this possibility by determining whether ectopic expression of transcription factors known to induce transcription of this gene...

  2. Insulin stimulation regulates AS160 and TBC1D1 phosphorylation sites in human skeletal muscle

    DEFF Research Database (Denmark)

    Middelbeek, R J W; Chambers, M A; Tantiwong, P

    2013-01-01

    Individuals with obesity and type 2 diabetes (T2D) are typically insulin resistant, exhibiting impaired skeletal muscle glucose uptake. Animal and cell culture experiments have shown that site-specific phosphorylation of the Rab-GTPase-activating proteins AS160 and TBC1D1 is critical for GLUT4 tr...... translocation facilitating glucose uptake, but their regulation in human skeletal muscle is not well understood....

  3. Structure based discovery of small molecules to regulate the activity of human insulin degrading enzyme.

    Directory of Open Access Journals (Sweden)

    Bilal Çakir

    Full Text Available BACKGROUND: Insulin-degrading enzyme (IDE is an allosteric Zn(+2 metalloprotease involved in the degradation of many peptides including amyloid-β, and insulin that play key roles in Alzheimer's disease (AD and type 2 diabetes mellitus (T2DM, respectively. Therefore, the use of therapeutic agents that regulate the activity of IDE would be a viable approach towards generating pharmaceutical treatments for these diseases. Crystal structure of IDE revealed that N-terminal has an exosite which is ∼30 Å away from the catalytic region and serves as a regulation site by orientation of the substrates of IDE to the catalytic site. It is possible to find small molecules that bind to the exosite of IDE and enhance its proteolytic activity towards different substrates. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we applied structure based drug design method combined with experimental methods to discover four novel molecules that enhance the activity of human IDE. The novel compounds, designated as D3, D4, D6, and D10 enhanced IDE mediated proteolysis of substrate V, insulin and amyloid-β, while enhanced degradation profiles were obtained towards substrate V and insulin in the presence of D10 only. CONCLUSION/SIGNIFICANCE: This paper describes the first examples of a computer-aided discovery of IDE regulators, showing that in vitro and in vivo activation of this important enzyme with small molecules is possible.

  4. Human muscle fiber type-specific insulin signaling: Impact of obesity and type 2 diabetes

    DEFF Research Database (Denmark)

    Albers, Peter Hjorth; Pedersen, Andreas J T; Birk, Jesper Bratz

    2015-01-01

    /or metabolic enzymes. Pools of type I and II fibers were prepared from biopsies of the vastus lateralis muscles from lean, obese and type 2 diabetic subjects before and after a hyperinsulinemic-euglycemic clamp. Type I fibers compared to type II fibers have higher protein levels of the insulin receptor, GLUT4......-responses to insulin adjusted for protein level were not different between fiber types. Independently of fiber type, insulin signaling was similar (TBC1D1, GS and PDH-E1α) or decreased (Akt and TBC1D4) in muscle from patients with type 2 diabetes compared to lean and obese subjects. We conclude that human type I......, hexokinase II, glycogen synthase (GS), pyruvate dehydrogenase (PDH-E1α) and a lower protein content of Akt2, TBC1D4 and TBC1D1. In type I fibers compared to type II fibers, the phosphorylation-response to insulin was similar (TBC1D4, TBC1D1 and GS) or decreased (Akt and PDH-E1α). Phosphorylation...

  5. Ohgata, the Single Drosophila Ortholog of Human Cereblon, Regulates Insulin Signaling-dependent Organismic Growth.

    Science.gov (United States)

    Wakabayashi, Satoru; Sawamura, Naoya; Voelzmann, André; Broemer, Meike; Asahi, Toru; Hoch, Michael

    2016-11-25

    Cereblon (CRBN) is a substrate receptor of the E3 ubiquitin ligase complex that is highly conserved in animals and plants. CRBN proteins have been implicated in various biological processes such as development, metabolism, learning, and memory formation, and their impairment has been linked to autosomal recessive non-syndromic intellectual disability and cancer. Furthermore, human CRBN was identified as the primary target of thalidomide teratogenicity. Data on functional analysis of CRBN family members in vivo, however, are still scarce. Here we identify Ohgata (OHGT), the Drosophila ortholog of CRBN, as a regulator of insulin signaling-mediated growth. Using ohgt mutants that we generated by targeted mutagenesis, we show that its loss results in increased body weight and organ size without changes of the body proportions. We demonstrate that ohgt knockdown in the fat body, an organ analogous to mammalian liver and adipose tissue, phenocopies the growth phenotypes. We further show that overgrowth is due to an elevation of insulin signaling in ohgt mutants and to the down-regulation of inhibitory cofactors of circulating Drosophila insulin-like peptides (DILPs), named acid-labile subunit and imaginal morphogenesis protein-late 2. The two inhibitory proteins were previously shown to be components of a heterotrimeric complex with growth-promoting DILP2 and DILP5. Our study reveals OHGT as a novel regulator of insulin-dependent organismic growth in Drosophila.

  6. Insulin-producing cells generated from dedifferentiated human pancreatic beta cells expanded in vitro.

    Directory of Open Access Journals (Sweden)

    Holger A Russ

    Full Text Available BACKGROUND: Expansion of beta cells from the limited number of adult human islet donors is an attractive prospect for increasing cell availability for cell therapy of diabetes. However, attempts at expanding human islet cells in tissue culture result in loss of beta-cell phenotype. Using a lineage-tracing approach we provided evidence for massive proliferation of beta-cell-derived (BCD cells within these cultures. Expansion involves dedifferentiation resembling epithelial-mesenchymal transition (EMT. Epigenetic analyses indicate that key beta-cell genes maintain open chromatin structure in expanded BCD cells, although they are not transcribed. Here we investigated whether BCD cells can be redifferentiated into beta-like cells. METHODOLOGY/PRINCIPAL FINDING: Redifferentiation conditions were screened by following activation of an insulin-DsRed2 reporter gene. Redifferentiated cells were characterized for gene expression, insulin content and secretion assays, and presence of secretory vesicles by electron microscopy. BCD cells were induced to redifferentiate by a combination of soluble factors. The redifferentiated cells expressed beta-cell genes, stored insulin in typical secretory vesicles, and released it in response to glucose. The redifferentiation process involved mesenchymal-epithelial transition, as judged by changes in gene expression. Moreover, inhibition of the EMT effector SLUG (SNAI2 using shRNA resulted in stimulation of redifferentiation. Lineage-traced cells also gave rise at a low rate to cells expressing other islet hormones, suggesting transition of BCD cells through an islet progenitor-like stage during redifferentiation. CONCLUSIONS/SIGNIFICANCE: These findings demonstrate for the first time that expanded dedifferentiated beta cells can be induced to redifferentiate in culture. The findings suggest that ex-vivo expansion of adult human islet cells is a promising approach for generation of insulin-producing cells for

  7. Molecular Basis of Catalytic Chamber-assisted Unfolding and Cleavage of Human Insulin by Human Insulin-degrading Enzyme*S⃞

    OpenAIRE

    Manolopoulou, Marika; Guo, Qing; Malito, Enrico; Schilling, Alexander B.; Tang, Wei-Jen

    2009-01-01

    Insulin is a hormone vital for glucose homeostasis, and insulin-degrading enzyme (IDE) plays a key role in its clearance. IDE exhibits a remarkable specificity to degrade insulin without breaking the disulfide bonds that hold the insulin A and B chains together. Using Fourier transform ion cyclotron resonance (FTICR) mass spectrometry to obtain high mass accuracy, and electron capture dissociation (ECD) to selectively break the disulfide bonds in gas phase fragmentatio...

  8. Insulin glargine overdose

    Directory of Open Access Journals (Sweden)

    Fatma Sari Dogan

    2012-01-01

    Full Text Available Insulin glargine is a long acting novel recombinant human insulin analogue indicated to improve glycemic control, in adults and children with type 1 diabetes mellitus and in adults with type 2 diabetes mellitus. The time course of action of insulins including insulin glargine may vary between individuals and/or within the same individual. Insulin glargine is given as a 24-h dosing regimen and has no documented half-life or peak effect. Hypoglycemia is the most common adverse effect of insulin, including insulin glargine. As with all insulins, the timing of hypoglycemia may differ among various insulin formulations. We present a case of a 76-year-old male insulin-dependent diabetic patient with refractory hypoglycemia secondary to an intentional overdose of insulin glargine. We would like to highlight the necessity of prolonging IV glucose infusion, for a much longer period than expected from pharmacokinetic properties of these insulin analogues after intentional massive overdose.

  9. Production of functional human insulin-like growth factor binding proteins (IGFBPs) using recombinant expression in HEK293 cells

    DEFF Research Database (Denmark)

    Wanscher, Anne Sofie Molsted; Williamson, Michael; Ebersole, Tasja Wainani;

    2015-01-01

    Insulin-like growth factor binding proteins (IGFBPs) display many functions in humans including regulation of the insulin-like growth factor (IGF) signaling pathway. The various roles of human IGFBPs make them attractive protein candidates in drug discovery. Structural and functional knowledge...... such as full-length human IGFBPs, still remains a challenge. Here we present a mammalian HEK293 expression method suitable for over-expression of secretory full-length human IGFBP-1 to -7. Protein purification of full-length human IGFBP-1, -2, -3 and -5 was conducted using a two-step chromatography procedure...

  10. High Insulin and Leptin Increase Resistin and Inflammatory Cytokine Production from Human Mononuclear Cells

    Directory of Open Access Journals (Sweden)

    Panayoula C. Tsiotra

    2013-01-01

    Full Text Available Resistin and the proinflammatory cytokines, such as TNF-α, IL-6, and IL-1β, produced by adipocytes, and macrophages, are considered to be important modulators of chronic inflammation contributing to the development of obesity and atherosclerosis. Human monocyte-enriched mononuclear cells, from ten healthy individuals, were exposed to high concentrations of insulin, leptin, and glucose (alone or in combination for 24 hours in vitro. Resistin, TNF-α, IL-6, and IL-1β production was examined and compared to that in untreated cells. High insulin and leptin concentrations significantly upregulated resistin and the cytokines. The subsequent addition of high glucose significantly upregulated resistin and TNF-α mRNA and protein secretion, while it did not have any effect on IL-6 or IL-1β production. By comparison, exposure to dexamethasone reduced TNF-α, IL-6, and IL-1β production, while at this time point it increased resistin protein secretion. These data suggest that the expression of resistin, TNF-α, IL-6, and IL-1β from human mononuclear cells, might be enhanced by the hyperinsulinemia and hyperleptinemia and possibly by the hyperglycemia in metabolic diseases as obesity, type 2 diabetes, and atherosclerosis. Therefore, the above increased production may contribute to detrimental effects of their increased adipocyte-derived circulating levels on systemic inflammation, insulin sensitivity, and endothelial function of these patients.

  11. Chromatin structure, epigenetic mechanisms and long-range interactions in the human insulin locus.

    Science.gov (United States)

    Xu, Z; Lefevre, G M; Felsenfeld, G

    2012-10-01

    Regulation of gene expression in eukaryotes is largely dependent on variations in chromatin structure. More recently, it has become clear that this may involve not only local chromatin organization but also distant regulatory elements that participate in large-scale chromatin architecture within the nucleus. We describe recent methods that make possible the detection of such structures and apply them to analysis of the human insulin (INS) locus in pancreatic islets. We show that the INS gene is part of an extended 'open' chromatin domain that includes adjacent genes as well. We also find that in islets, the INS promoter is in physical contact with distant sites on the same human chromosome and notably, with the SYT8 gene, located nearly 300 kb away. The strength of the contact between INS and SYT8 is increased by glucose, and this results in stimulation of SYT8 expression. Inhibition of INS transcription decreases SYT8 expression. Furthermore, downregulation of SYT8 results in decreased secretion of insulin. Our results thus establish the existence of a regulatory network between the INS gene and other distant genes through long-range physical interactions, and suggest that such networks may have general importance for insulin biology and diabetes.

  12. X-ray investigation of gene-engineered human insulin crystallized from a solution containing polysialic acid

    Science.gov (United States)

    Timofeev, V. I.; Chuprov-Netochin, R. N.; Samigina, V. R.; Bezuglov, V. V.; Miroshnikov, K. A.; Kuranova, I. P.

    2010-01-01

    Attempts to crystallize the noncovalent complex of recombinant human insulin with polysialic acid were carried out under normal and microgravity conditions. Both crystal types belonged to the same space group, I213, with unit-cell parameters a = b = c = 77.365 Å, α = β = γ = 90.00°. The reported space group and unit-cell parameters are almost identical to those of cubic insulin reported in the PDB. The results of X-ray studies confirmed that the crystals obtained were cubic insulin crystals and that they contained no polysialic acid or its fragments. Electron-density maps were calculated using X-ray diffraction sets from earth-grown and microgravity-grown crystals and the three-dimensional structure of the insulin molecule was determined and refined. The conformation and secondary-structural elements of the insulin molecule in different crystal forms were compared. PMID:20208155

  13. Regulation of autophagy in human skeletal muscle: effects of exercise, exercise training and insulin stimulation

    DEFF Research Database (Denmark)

    Fritzen, Andreas Mæchel; Madsen, Agnete Louise Bjerregaard; Kleinert, Maximilian

    2016-01-01

    . The decrease in LC3-II/LC3-I ratio did not correlate with activation of AMPK trimer complexes in human muscle. Consistently, pharmacological AMPK activation with AICAR in mouse muscle did not affect the LC3-II/LC3-I ratio. Four hours after exercise, insulin further reduced (p80......%) in muscle of the exercised and non-exercised leg in man. This coincided with increased Ser-757 phosphorylation of ULK1, which is suggested as an mTORC1 target. Accordingly, inhibition of mTOR signalling in mouse muscle prevented the ability of insulin to reduce the LC3-II/LC3-I ratio. In response to 3 weeks...

  14. Human amnion epithelial cells can be induced to differentiate into functional insulin-producing cells

    Institute of Scientific and Technical Information of China (English)

    Yanan Hou; Qin Huang; Tianjin Liu; Lihe Guo

    2008-01-01

    Pancreatic islet transplantation has demonstrated that long-term insulin independence may be achieved in patients suffering from diabetes mellitus type 1. However, limited availability of islet tissue means that new sources of insulinproducing cells that are responsive to glucose are required. Here, we show that human amnion epithelial cells (HAEC) can be induced to differentiate into functional insulinproducing cells in vitro. After induction of differentiation, HAEC expressed multiple pancreatic --cell genes, including insulin, pancreas duodenum homeobox-1, paired box gene 6,NK2 transcription factor-related locus 2, Islet 1, glucokinase,and glucose transporter-2, and released C-peptide in a glucose-regulated manner in response to other extracellular stimulations. The transplantation of induced HAEC into streptozotocin-induced diabetic C57 mice reversed hyperglycemia, restored body weight, and maintained euglycemia for 30 d. These findings indicated that HAEC may be a new source for cell replacement therapy in type 1 diabetes.

  15. Reactivation of the insulin-like growth factor-Ⅱ signaling pathway in human hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Kai Breuhahn; Peter Schirmacher

    2008-01-01

    Constitutive activation of the insulin-like growth factor (IGF)-signaling axis is frequently observed in human hepatocellular carcinoma (HCC). Especially the over-expression of the fetal growth factor IGF-Ⅱ, IGF-Ⅰ receptor (IGF-IR), and cytoplasmic downstream effectors such as insulin-receptor substrates (IRS) contribute to proliferation, anti-apoptosis, and invasive behavior. This review focuses on the relevant alterations in this signaling pathway and independent in vivo models that support the central role IGF-Ⅱ signaling during HCC development and progression. Since this pathway has become the center of interest as a target for potential anti-cancer therapy in many types of malignancies, various experimental strategies have been developed, including neutralizing antibodies and selective receptor ki-nase inhibitors, with respect to the specific and efficient reduction of oncogenic IGF-Ⅱ/IGF-IR-signaling.

  16. Intake of Lactobacillus reuteri Improves Incretin and Insulin Secretion in Glucose-Tolerant Humans

    DEFF Research Database (Denmark)

    Simon, Marie-Christine; Strassburger, Klaus; Nowotny, Bettina;

    2015-01-01

    OBJECTIVE: Ingestion of probiotics can modify gut microbiota and alter insulin resistance and diabetes development in rodents. We hypothesized that daily intake of Lactobacillus reuteri increases insulin sensitivity by changing cytokine release and insulin secretion via modulation of the release...

  17. Pancreatic Transdifferentiation and Glucose-Regulated Production of Human Insulin in the H4IIE Rat Liver Cell Line

    Directory of Open Access Journals (Sweden)

    Binhai Ren

    2016-04-01

    Full Text Available Due to the limitations of current treatment regimes, gene therapy is a promising strategy being explored to correct blood glucose concentrations in diabetic patients. In the current study, we used a retroviral vector to deliver either the human insulin gene alone, the rat NeuroD1 gene alone, or the human insulin gene and rat NeuroD1 genes together, to the rat liver cell line, H4IIE, to determine if storage of insulin and pancreatic transdifferentiation occurred. Stable clones were selected and expanded into cell lines: H4IIEins (insulin gene alone, H4IIE/ND (NeuroD1 gene alone, and H4IIEins/ND (insulin and NeuroD1 genes. The H4IIEins cells did not store insulin; however, H4IIE/ND and H4IIEins/ND cells stored 65.5 ± 5.6 and 1475.4 ± 171.8 pmol/insulin/5 × 106 cells, respectively. Additionally, several β cell transcription factors and pancreatic hormones were expressed in both H4IIE/ND and H4IIEins/ND cells. Electron microscopy revealed insulin storage vesicles in the H4IIE/ND and H4IIEins/ND cell lines. Regulated secretion of insulin to glucose (0–20 mmol/L was seen in the H4IIEins/ND cell line. The H4IIEins/ND cells were transplanted into diabetic immunoincompetent mice, resulting in normalization of blood glucose. This data shows that the expression of NeuroD1 and insulin in liver cells may be a useful strategy for inducing islet neogenesis and reversing diabetes.

  18. Understanding the structural differences between spherical and rod-shaped human insulin nanoparticles produced by supercritical fluids precipitation.

    Science.gov (United States)

    Park, Yeonju; Seo, Yongil; Chae, Boknam; Pyo, Dongjin; Chung, Hoeil; Hwang, Hyonseok; Jung, Young Mee

    2015-02-01

    In this study, the thermal denaturation mechanism and secondary structures of two types of human insulin nanoparticles produced by a process of solution-enhanced dispersion by supercritical fluids using dimethyl sulfoxide (DMSO) and ethanol (EtOH) solutions of insulin are investigated using spectroscopic approaches and molecular dynamics calculations. First, the temperature-dependent IR spectra of spherical and rod-shaped insulin nanoparticles prepared from DMSO and EtOH solution, respectively, are analyzed using principal component analysis (PCA) and 2D correlation spectroscopy to obtain a deeper understanding of the molecular structures and thermal behavior of the two insulin particle shapes. All-atom molecular dynamics (AAMD) calculations are performed to investigate the influence of the solvent molecules on the production of the insulin nanoparticles and to elucidate the geometric differences between the two types of nanoparticles. The results of the PCA, the 2D correlation spectroscopic analysis, and the AAMD calculations clearly reveal that the thermal denaturation mechanisms and the degrees of hydrogen bonding in the spherical and rod-shaped insulin nanoparticles are different. The polarity of the solvent might not alter the structure or function of the insulin produced, but the solvent polarity does influence the synthesis of different shapes of insulin nanoparticles.

  19. Insulin-like growth factors, insulin-like growth factor-binding proteins, insulin-like growth factor-binding protein-3 protease, and growth hormone-binding protein in lipodystrophic human immunodeficiency virus-infected patients

    DEFF Research Database (Denmark)

    Haugaard, Steen B; Andersen, Ove; Hansen, Birgitte Rønde;

    2004-01-01

    Human immunodeficiency virus (HIV)-lipodystrophy is associated with impaired growth hormone (GH) secretion. It remains to be elucidated whether insulin-like growth factors (IGFs), IGF-binding proteins (IGFBPs), IGFBP-3 protease, and GH-binding protein (GHBP) are abnormal in HIV-lipodystrophy....... These parameters were measured in overnight fasting serum samples from 16 Caucasian males with HIV-lipodystrophy (LIPO) and 15 Caucasian HIV-infected males without lipodystrophy (NONLIPO) matched for age, weight, duration of HIV infection, and antiretroviral therapy. In LIPO, abdominal fat mass and insulin...... of bioactive IGF-I in HIV-lipodystrophy....

  20. Unraveling the Symmetry Ambiguity in a Hexamer: Calculation of the R6 Human Insulin Structure

    DEFF Research Database (Denmark)

    O'Donoghue, Sean I.; Chang, Xiaoqing; Abseher, Roger;

    2000-01-01

    ambiguous distance restraints, insulin hexamer, principal component analysis, solution structure, symmetric oligomers......ambiguous distance restraints, insulin hexamer, principal component analysis, solution structure, symmetric oligomers...

  1. Human umbilical cord mesenchymal stem cells derived from Wharton's jelly differentiate into insulin-producing cells in vitro

    Institute of Scientific and Technical Information of China (English)

    WANG Hong-wu; LIN Li-min; HE Hong-yan; YOU Fang; LI Wei-zhong; HUANG Tian-hua; MA Gui-xia; MA Lian

    2011-01-01

    Background Islet transplantation is an effective way of reversing type Ⅰ diabetes. However, islet transplantation is hampered by issues such as immune rejection and shortage of donor islets. Mesenchymal stem cells can differentiate into insulin-producing cells. However, the potential of human umbilical cord mesenchymal stem cells (huMSCs) to become insulin-producing cells remains undetermined.Methods We isolated and induced cultured huMSCs under islet cell culture conditions. The response of huMSCs were monitored under an inverted phase contrast microscope. Immunocytochemical and immunofluorescence staining methods were used to measure insulin and glucagon protein levels. Reverse transcription-polymerase chain reaction (RT-PCR) was performed to detect gene expression of human insulin and PDX-1. Dithizone-staining was employed to determine the zinc contents in huMSCs. Insulin secretion was also evaluated through radioimmunoassay.Results HuMSCs induced by nicotinamide and β-mercaptoethanol or by neurogenic differentiation 1 gene (NeuroD1)transfection gradually changed morphology from typically elongated fibroblast-shaped cells to round cells. They had a tendency to form clusters. Immunocytochemical studies showed positive expression of human insulin and glucagon in these cells in response to induction. RT-PCR experiments found that huMSCs expressed insulin and PDX-1 genes following induction and dithizone stained the cytoplasm of huMSCs a brownish red color after induction. Insulin secretion in induced huMSCs was significantly elevated compared with the control group (t=6.183, P<0.05).Conclusions HuMSCs are able to differentiate into insulin-producing cells in vitro. The potential use of huMSCs in βcell replacement therapy of diabetes needs to be studied further.

  2. Glucagon-to-insulin ratio is pivotal for splanchnic regulation of FGF-21 in humans

    DEFF Research Database (Denmark)

    Hansen, Jakob Schiøler; Clemmesen, Jens Otto; Secher, Niels Henry

    2015-01-01

    BACKGROUND & AIMS: Fibroblast growth factor 21 (FGF-21) is a liver-derived metabolic regulator induced by energy deprivation. However, its regulation in humans is incompletely understood. We addressed the origin and regulation of FGF-21 secretion in humans. METHODS: By determination of arterial......-to-venous differences over the liver and the leg during exercise, we evaluated the organ-specific secretion of FGF-21 in humans. By four different infusion models manipulating circulating glucagon and insulin, we addressed the interaction of these hormones on FGF-21 secretion in humans. RESULTS: We demonstrate...... that the splanchnic circulation secretes FGF-21 at rest and that it is rapidly enhanced during exercise. In contrast, the leg does not contribute to the systemic levels of FGF-21. To unravel the mechanisms underlying the regulation of exercise-induced hepatic release of FGF-21, we manipulated circulating glucagon...

  3. Solution structure of human insulin-like growth factor II; recognition sites for receptors and binding proteins.

    OpenAIRE

    Terasawa, H; Kohda, D.; Hatanaka, H; Nagata, K.; Higashihashi, N; Fujiwara, H.; Sakano, K; Inagaki, F.

    1994-01-01

    The three-dimensional structure of human insulin-like growth factor II was determined at high resolution in aqueous solution by NMR and simulated annealing based calculations. The structure is quite similar to those of insulin and insulin-like growth factor I, which consists of an alpha-helix followed by a turn and a strand in the B-region and two antiparallel alpha-helices in the A-region. However, the regions of Ala1-Glu6, Pro31-Arg40 and Thr62-Glu67 are not well-defined for lack of distanc...

  4. Differential effects of prednisone and growth hormone on fuel metabolism and insulin antagonism in humans

    Energy Technology Data Exchange (ETDEWEB)

    Horber, F.F.; Marsh, H.M.; Haymond, M.W. (Mayo Clinic, Rochester, MN (USA))

    1991-01-01

    Human growth hormone (hGH) and prednisone cause insulin resistance and glucose intolerance. However, it is unknown whether hGH and prednisone antagonize insulin action on protein, fat, and carbohydrate metabolism by a common or independent mechanism. Therefore, protein, fat, and carbohydrate metabolism was assessed simultaneously in four groups of eight subjects each after 7 days of placebo, recombinant DNA hGH (rhGH; 0.1 mg.kg-1.day-1), prednisone (0.8 mg.kg-1.day-1), or rhGH and prednisone administration after an 18-h fast and during gut infusion of glucose and amino acids (fed state). Fasting plasma glucose concentrations were similar during placebo and rhGH but elevated (P less than 0.001) during combined treatment, whereas plasma insulin concentrations were higher (237 +/- 57 pmol/ml, P less than 0.001) during combined than during placebo, rhGH, or prednisone treatment (34, 52, and 91 pM, respectively). In the fed state, plasma glucose concentrations were elevated only during combined treatment (11.3 +/- 2.1 mM, P less than 0.001). Plasma insulin concentrations were elevated during therapy with prednisone alone and rhGH alone (667 +/- 72 and 564 +/- 65 pmol/ml, respectively, P less than 0.001) compared with placebo (226 +/- 44 pmol/ml) but lower than with the combined rhGH and prednisone treatment (1249 +/- 54 pmol/ml, P less than 0.01). Protein oxidation {sup 14}C leucine increased (P less than 0.001) with prednisone therapy, decreased (P less than 0.001) with rhGH treatment, and was normal during the combined treatment.

  5. Insulin and GH signaling in human skeletal muscle in vivo following exogenous GH exposure: impact of an oral glucose load.

    Directory of Open Access Journals (Sweden)

    Thomas Krusenstjerna-Hafstrøm

    Full Text Available INTRODUCTION: GH induces acute insulin resistance in skeletal muscle in vivo, which in rodent models has been attributed to crosstalk between GH and insulin signaling pathways. Our objective was to characterize time course changes in signaling pathways for GH and insulin in human skeletal muscle in vivo following GH exposure in the presence and absence of an oral glucose load. METHODS: Eight young men were studied in a single-blinded randomized crossover design on 3 occasions: 1 after an intravenous GH bolus 2 after an intravenous GH bolus plus an oral glucose load (OGTT, and 3 after intravenous saline plus OGTT. Muscle biopsies were taken at t = 0, 30, 60, and 120. Blood was sampled at frequent intervals for assessment of GH, insulin, glucose, and free fatty acids (FFA. RESULTS: GH increased AUC(glucose after an OGTT (p<0.05 without significant changes in serum insulin levels. GH induced phosphorylation of STAT5 independently of the OGTT. Conversely, the OGTT induced acute phosphorylation of the insulin signaling proteins Akt (ser(473 and thr(308, and AS160.The combination of OGTT and GH suppressed Akt activation, whereas the downstream expression of AS160 was amplified by GH. WE CONCLUDED THE FOLLOWING: 1 A physiological GH bolus activates STAT5 signaling pathways in skeletal muscle irrespective of ambient glucose and insulin levels 2 Insulin resistance induced by GH occurs without a distinct suppression of insulin signaling proteins 3 The accentuation of the glucose-stimulated activation of AS 160 by GH does however indicate a potential crosstalk between insulin and GH. TRIAL REGISTRATION: ClinicalTrials.gov NCT00477997.

  6. Insulin stimulates translocation of human GLUT4 to the membrane in fat bodies of transgenic Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Georgeta Crivat

    Full Text Available The fruit fly Drosophila melanogaster is an excellent model system for studies of genes controlling development and disease. However, its applicability to physiological systems is less clear because of metabolic differences between insects and mammals. Insulin signaling has been studied in mammals because of relevance to diabetes and other diseases but there are many parallels between mammalian and insect pathways. For example, deletion of Drosophila Insulin-Like Peptides resulted in 'diabetic' flies with elevated circulating sugar levels. Whether this situation reflects failure of sugar uptake into peripheral tissues as seen in mammals is unclear and depends upon whether flies harbor the machinery to mount mammalian-like insulin-dependent sugar uptake responses. Here we asked whether Drosophila fat cells are competent to respond to insulin with mammalian-like regulated trafficking of sugar transporters. Transgenic Drosophila expressing human glucose transporter-4 (GLUT4, the sugar transporter expressed primarily in insulin-responsive tissues, were generated. After expression in fat bodies, GLUT4 intracellular trafficking and localization were monitored by confocal and total internal reflection fluorescence microscopy (TIRFM. We found that fat body cells responded to insulin with increased GLUT4 trafficking and translocation to the plasma membrane. While the amplitude of these responses was relatively weak in animals reared on a standard diet, it was greatly enhanced in animals reared on sugar-restricted diets, suggesting that flies fed standard diets are insulin resistant. Our findings demonstrate that flies are competent to mobilize translocation of sugar transporters to the cell surface in response to insulin. They suggest that Drosophila fat cells are primed for a response to insulin and that these pathways are down-regulated when animals are exposed to constant, high levels of sugar. Finally, these studies are the first to use TIRFM to

  7. Highly efficient differentiation of human ES cells and iPS cells into mature pancreatic insulin-producing cells

    Institute of Scientific and Technical Information of China (English)

    Donghui Zhang; Wei Jiang; Meng Liu; Xin Sui; Xiaolei Yin; Song Chen; Yan Shi; Hongkui Deng

    2009-01-01

    Human pluripotent stem cells represent a potentially unlimited source of functional pancreatic endocrine lineage cells. Here we report a highly efficient approach to induce human embryonic stem (ES) cells and induced pluripotent stem (iPS) cells to differentiate into mature insulin-producing cells in a chemical-defined culture system. The differentiated human ES cells obtained by this approach comprised nearly 25% insulin-positive cells as assayed by flow cytometry analysis, which released insulin/C-peptide in response to glucose stimuli in a manner comparable to that of adult human islets. Most of these insulin-producing cells co-expressed mature β cell-specific markers such as NKX6-1 and PDX1, indicating a similar gene expression pattern to adult islet β cells in vivo. In this study, we also demonstrated that EGF facilitates the expansion of PDX1-positive pancreatic progenitors. Moreover, our protocol also succeeded in efficiently inducing human iPS cells to differentiate into insulin-producing cells. Therefore, this work not only provides a new model to study the mechanism of human pancreatic specialization and maturation in vitro, but also enhances the possibility of utilizing patient-specific iPS cells for the treatment of diabetes.

  8. AMP-activated protein kinase (AMPK) regulates the insulin-induced activation of the nitric oxide synthase in human platelets.

    Science.gov (United States)

    Fleming, Ingrid; Schulz, Christian; Fichtlscherer, Birgit; Kemp, Bruce E; Fisslthaler, Beate; Busse, Rudi

    2003-11-01

    Little is known about the signaling cascades that eventually regulate the activity of the endothelial nitric oxide synthase (eNOS) in platelets. Here, we investigated the effects of insulin on the phosphorylation and activation of eNOS in washed human platelets and in endothelial cells. Insulin activated the protein kinase Akt in cultured endothelial cells and increased the phosphorylation of eNOS on Ser(1177) but failed to increase endothelial cyclic GMP levels or to elicit the relaxation of endothelium-intact porcine coronary arteries. In platelets, insulin also elicited the activation of Akt as well as the phosphorylation of eNOS and initiated NO production which was associated with increased cyclic GMP levels and the inhibition of thrombin-induced aggregation. The insulin-induced inhibition of aggregation was accompanied by a decreased Ca(2+) response to thrombin and was also prevented by N(omega) nitro-L-arginine. In platelets, but not in endothelial cells, insulin induced the activation of the AMP-activated protein kinase (AMPK), a metabolic stress-sensing kinase which was sensitive to the phosphatidylinositol 3-kinase (PI3-K) inhibitor wortmannin and the AMPK inhibitor iodotubercidin. Moreover, the insulin-mediated inhibition of thrombin-induced aggregation was prevented by iodotubercidin. Insulin-independent activation of the AMPK using 5-aminoimidazole-4-carboxamide ribonucleoside, increased platelet eNOS phosphorylation, increased cyclic GMP levels and attenuated platelet aggregation. These results highlight the differences in the signal transduction cascade activated by insulin in endothelial cells and platelets, and demonstrate that insulin stimulates the formation of NO in human platelets, in the absence of an increase in Ca(2+), by acti-vating PI3-K and AMPK which phosphorylates eNOS on Ser(1177).

  9. A prospective randomised cross-over study of the effect of insulin analogues and human insulin on the frequency of severe hypoglycaemia in patients with type 1 diabetes and recurrent hypoglycaemia (the HypoAna trial)

    DEFF Research Database (Denmark)

    Kristensen, Peter Lommer; Pedersen-Bjergaard, Uirik; Beck-Nielsen, Henning

    2012-01-01

    of insulin analogues on glycaemic control has been documented in large trials, while their effect on the frequency of severe hypoglycaemia is less clear, especially in patients with recurrent severe hypoglycaemia. The HypoAna Trial is designed to investigate whether short-acting and long-acting insulin...... analogues in comparison with human insulin are superior in reducing the occurrence of severe hypoglycaemic episodes in patients with recurrent hypoglycaemia. This paper reports the study design of the HypoAna Trial....

  10. Etiske Aspekter Inden For Brugen Af Humane Embryoniske Stamceller til Insulin Fremstillende Forskning

    OpenAIRE

    Kyhnauv, Ida Johanne; Køneke, Casper; Frost, Jeanne Birgit; Berendtsen, Nicolai Tubæk; Knudsen, Peter Alexander

    2016-01-01

    This study focuses on the ethical challenges regarding differentiation and creation of insulin producing cells from human embryonic stem cells (hESCs). We include the development, advantages and disadvantages of using hESCs and induced pluripotent stem cells (iPSCs). We outline the ethical aspects concerning the use of hESC in research, based on our case as well as ethical and biological theories on the making of hESCs and iPSCs. We likewise include legislation and articles, where ethnical di...

  11. Relationship between pancreatic vesicular monoamine transporter 2 (VMAT2) and insulin expression in human pancreas

    OpenAIRE

    Saisho, Yoshifumi; Harris, Paul E.; Butler, Alexandra E.; Galasso, Ryan; GURLO, TATYANA; Rizza, Robert A.; Butler, Peter C.

    2008-01-01

    Vesicular monoamine transporter 2 (VMAT2) is expressed in pancreatic beta cells and has recently been proposed as a target for measurement of beta cell mass in vivo. We questioned, (1) What proportion of beta cells express VMAT2? (2) Is VMAT2 expressed by other pancreatic endocrine or non-endocrine cells? (3) Is the relationship between VMAT2 and insulin expression disturbed in type 1 (T1DM) or type 2 diabetes (T2DM)? Human pancreas (7 non-diabetics, 5 T2DM, 10 T1DM) was immunostained for ins...

  12. Two insulin-like growth factor I messenger RNAs are expressed in human liver.

    OpenAIRE

    Rotwein, P

    1986-01-01

    Through use of a synthetic oligonucleotide probe, human insulin-like growth factor I (IGF-I) cDNA clones were isolated from a liver library. Two types of cDNAs were defined by restriction enzyme analysis and DNA sequencing. Both encode IGF-I precursors of either 195 or 153 amino acids. The two predicted protein precursors are identical from their amino terminus to a lysine residue 16 codons beyond the IGF-I sequence, and then they diverge. Both cDNAs predict additional unique carboxyl-termina...

  13. Structure Based Discovery of Small Molecules to Regulate the Activity of Human Insulin Degrading Enzyme

    OpenAIRE

    Bilal Çakir; Onur Dağliyan; Ezgi Dağyildiz; İbrahim Bariş; Ibrahim Halil Kavakli; Seda Kizilel; Metin Türkay

    2012-01-01

    Structure Based Discovery of Small Molecules to Regulate the Activity of Human Insulin Degrading Enzyme Bilal C¸ akir1, Onur Dag˘ liyan1, Ezgi Dag˘ yildiz1, I˙brahim Baris¸1, Ibrahim Halil Kavakli1,2*, Seda Kizilel1*, Metin Tu¨ rkay3* 1 Department of Chemical and Biological Engineering, Koc¸ University, Sariyer, Istanbul, Turkey, 2 Department of Molecular Biology and Genetics, Koc¸ University, Sariyer, Istanbul, Turkey, 3 Department of Industrial Engineering, Koc¸ University...

  14. Human Liver Cells Expressing Albumin and Mesenchymal Characteristics Give Rise to Insulin-Producing Cells

    Directory of Open Access Journals (Sweden)

    Irit Meivar-Levy

    2011-01-01

    Full Text Available Activation of the pancreatic lineage in the liver has been suggested as a potential autologous cell replacement therapy for diabetic patients. Transcription factors-induced liver-to-pancreas reprogramming has been demonstrated in numerous species both in vivo and in vitro. However, human-derived liver cells capable of acquiring the alternate pancreatic repertoire have never been characterized. It is yet unknown whether hepatic-like stem cells or rather adult liver cells give rise to insulin-producing cells. Using an in vitro experimental system, we demonstrate that proliferating adherent human liver cells acquire mesenchymal-like characteristics and a considerable level of cellular plasticity. However, using a lineage-tracing approach, we demonstrate that insulin-producing cells are primarily generated in cells enriched for adult hepatic markers that coexpress both albumin and mesenchymal markers. Taken together, our data suggest that adult human hepatic tissue retains a substantial level of developmental plasticity, which could be exploited in regenerative medicine approaches.

  15. Expression, content, and localization of insulin-like growth factor I in human achilles tendon

    DEFF Research Database (Denmark)

    Olesen, Jens L; Heinemeier, Katja M; Langberg, Henning;

    2006-01-01

    by immunoflourometric assay, real-time PCR, and immunohistochemistry used to localize and determine expression of IGF-I and IGFBP-4 in 6 postmortem human Achilles tendons. Tendon tissue concentrations of IGF-I were found to be 0.53 +/- 0.10 ng/g. Furthermore, we demonstrated that IGF-I and IGFBP-4 are localized around......In animals insulin-like growth factor I (IGF-I) stimulates collagen production by fibroblasts and is expressed in tendons together with its binding protein 4 (IGFBP-4). However, the presence of IGF-I and IGFBP-4 in human tendon tissue is not described. Tissue IGF-I content was examined...... the tendon fibroblasts and that mRNA for IGF-I and IGFBP-4 can be determined in human tendon tissue. The present study adds support for the roles of IGF-I and IGFBP-4 in the regulation of tendon adaptive responses to mechanical loading....

  16. Inhibition of human insulin gene transcription and MafA transcriptional activity by the dual leucine zipper kinase.

    Science.gov (United States)

    Stahnke, Marie-Jeannette; Dickel, Corinna; Schröder, Sabine; Kaiser, Diana; Blume, Roland; Stein, Roland; Pouponnot, Celio; Oetjen, Elke

    2014-09-01

    Insulin biosynthesis is an essential β-cell function and inappropriate insulin secretion and biosynthesis contribute to the pathogenesis of diabetes mellitus type 2. Previous studies showed that the dual leucine zipper kinase (DLK) induces β-cell apoptosis. Since β-cell dysfunction precedes β-cell loss, in the present study the effect of DLK on insulin gene transcription was investigated in the HIT-T15 β-cell line. Downregulation of endogenous DLK increased whereas overexpression of DLK decreased human insulin gene transcription. 5'- and 3'-deletion human insulin promoter analyses resulted in the identification of a DLK responsive element that mapped to the DNA binding-site for the β-cell specific transcription factor MafA. Overexpression of DLK wild-type but not its kinase-dead mutant inhibited MafA transcriptional activity conferred by its transactivation domain. Furthermore, in the non-β-cell line JEG DLK inhibited MafA overexpression-induced human insulin promoter activity. Overexpression of MafA and DLK or its kinase-dead mutant into JEG cells revealed that DLK but not its mutant reduced MafA protein content. Inhibition of the down-stream DLK kinase c-Jun N-terminal kinase (JNK) by SP600125 attenuated DLK-induced MafA loss. Furthermore, mutation of the serine 65 to alanine, shown to confer MafA protein stability, increased MafA-dependent insulin gene transcription and prevented DLK-induced MafA loss in JEG cells. These data suggest that DLK by activating JNK triggers the phosphorylation and degradation of MafA thereby attenuating insulin gene transcription. Given the importance of MafA for β-cell function, the inhibition of DLK might preserve β-cell function and ultimately retard the development of diabetes mellitus type 2.

  17. Insulin-producing cells from adult human bone marrow mesenchymal stem cells control streptozotocin-induced diabetes in nude mice.

    Science.gov (United States)

    Gabr, Mahmoud M; Zakaria, Mahmoud M; Refaie, Ayman F; Ismail, Amani M; Abou-El-Mahasen, Mona A; Ashamallah, Sylvia A; Khater, Sherry M; El-Halawani, Sawsan M; Ibrahim, Rana Y; Uin, Gan Shu; Kloc, Malgorzata; Calne, Roy Y; Ghoneim, Mohamed A

    2013-01-01

    Harvesting, expansion, and directed differentiation of human bone marrow-derived mesenchymal stem cells (BM-MSCs) could provide an autologous source of surrogate β-cells that would alleviate the limitations of availability and/or allogenic rejection following pancreatic or islet transplantation. Bone marrow cells were obtained from three adult type 2 diabetic volunteers and three nondiabetic donors. After 3 days in culture, adherent MSCs were expanded for two passages. At passage 3, differentiation was carried out in a three-staged procedure. Cells were cultured in a glucose-rich medium containing several activation and growth factors. Cells were evaluated in vitro by flow cytometry, immunolabeling, RT-PCR, and human insulin and c-peptide release in responses to increasing glucose concentrations. One thousand cell clusters were inserted under the renal capsule of diabetic nude mice followed by monitoring of their diabetic status. At the end of differentiation, ∼5-10% of cells were immunofluorescent for insulin, c-peptide or glucagon; insulin, and c-peptide were coexpressed. Nanogold immunolabeling for electron microscopy demonstrated the presence of c-peptide in the rough endoplasmic reticulum. Insulin-producing cells (IPCs) expressed transcription factors and genes of pancreatic hormones similar to those expressed by pancreatic islets. There was a stepwise increase in human insulin and c-peptide release by IPCs in response to increasing glucose concentrations. Transplantation of IPCs into nude diabetic mice resulted in control of their diabetic status for 3 months. The sera of IPC-transplanted mice contained human insulin and c-peptide but negligible levels of mouse insulin. When the IPC-bearing kidneys were removed, rapid return of diabetic state was noted. BM-MSCs from diabetic and nondiabetic human subjects could be differentiated without genetic manipulation to form IPCs that, when transplanted, could maintain euglycemia in diabetic mice for 3 months

  18. Reduced insulin exocytosis in human pancreatic β-cells with gene variants linked to type 2 diabetes

    DEFF Research Database (Denmark)

    Rosengren, Anders H; Braun, Matthias; Mahdi, Taman;

    2012-01-01

    The majority of genetic risk variants for type 2 diabetes (T2D) affect insulin secretion, but the mechanisms through which they influence pancreatic islet function remain largely unknown. We functionally characterized human islets to determine secretory, biophysical, and ultrastructural features...... in relation to genetic risk profiles in diabetic and nondiabetic donors. Islets from donors with T2D exhibited impaired insulin secretion, which was more pronounced in lean than obese diabetic donors. We assessed the impact of 14 disease susceptibility variants on measures of glucose sensing, exocytosis......, and structure. Variants near TCF7L2 and ADRA2A were associated with reduced glucose-induced insulin secretion, whereas susceptibility variants near ADRA2A, KCNJ11, KCNQ1, and TCF7L2 were associated with reduced depolarization-evoked insulin exocytosis. KCNQ1, ADRA2A, KCNJ11, HHEX/IDE, and SLC2A2 variants...

  19. Interactions of short-acting, intermediate-acting and pre-mixed human insulins with free radicals--Comparative EPR examination.

    Science.gov (United States)

    Olczyk, Paweł; Komosinska-Vassev, Katarzyna; Ramos, Paweł; Mencner, Łukasz; Olczyk, Krystyna; Pilawa, Barbara

    2015-07-25

    Electron paramagnetic resonance (EPR) spectroscopy was used to examine insulins interactions with free radicals. Human recombinant DNA insulins of three groups were studied: short-acting insulin (Insuman Rapid); intermediate-acting insulins (Humulin N, Insuman Basal), and pre-mixed insulins (Humulin M3, Gensulin M50, Gensulin M40, Gensulin M30). The aim of an X-band (9.3GHz) study was comparative analysis of antioxidative properties of the three groups of human insulins. DPPH was used as a stable free radical model. Amplitudes of EPR lines of DPPH as the paramagnetic free radical reference, and DPPH interacting with the individual tested insulins were compared. For all the examined insulins kinetics of their interactions with free radicals up to 60 min were obtained. The strongest interactions with free radicals were observed for the short-acting insulin - Insuman Rapid. The lowest interactions with free radicals were characteristic for intermediate-acting insulin - Insuman Basal. The pre-mixed insulins i.e. Humulin M3 and Gensulin M50 revealed the fastest interactions with free radicals. The short acting, intermediate acting and premixed insulins have been found to be effective agents in reducing free radical formation in vitro and should be further considered as potential useful tools in attenuation of oxidative stress in diabetic patients.

  20. Increased bioactive lipids content in human subcutaneous and epicardial fat tissue correlates with insulin resistance.

    Science.gov (United States)

    Błachnio-Zabielska, Agnieszka U; Baranowski, Marcin; Hirnle, Tomasz; Zabielski, Piotr; Lewczuk, Anna; Dmitruk, Iwona; Górski, Jan

    2012-12-01

    Obesity is a risk factor for metabolic diseases. Intramuscular lipid accumulation of ceramides, diacylglycerols, and long chain acyl-CoA is responsible for the induction of insulin resistance. These lipids are probably implicated in obesity-associated insulin resistance not only in skeletal muscle but also in fat tissue. Only few data are available about ceramide content in human subcutaneous adipose tissue. However, there are no data on DAG and LCACoA content in adipose tissue. The aim of our study was to measure the lipids content in human SAT and epicardial adipose tissue we sought to determine the bioactive lipids content by LC/MS/MS in fat tissue from lean non-diabetic, obese non-diabetic, and obese diabetic subjects and test whether the lipids correlate with HOMA-IR. We found, that total content of measured lipids was markedly higher in OND and OD subjects in both types of fat tissue (for all p fat tissue and the particular lipids content positively correlates with HOMA-IR.

  1. Characterization of lipid metabolism in insulin-sensitive adipocytes differentiated from immortalized human mesenchymal stem cells.

    Science.gov (United States)

    Prawitt, Janne; Niemeier, Andreas; Kassem, Moustapha; Beisiegel, Ulrike; Heeren, Joerg

    2008-02-15

    There is a great demand for cell models to study human adipocyte function. Here we describe the adipogenic differentiation of a telomerase-immortalized human mesenchymal stem cell line (hMSC-Tert) that maintains numerous features of terminally differentiated adipocytes even after prolonged withdrawal of the peroxisome proliferator activated receptor gamma (PPARgamma) agonist rosiglitazone. Differentiated hMSC-Tert developed the characteristic monolocular phenotype of mature adipocytes. The expression of adipocyte specific markers was highly increased during differentiation. Most importantly, the presence of the PPARgamma agonist rosiglitazone was not required for the stable expression of lipoprotein lipase, adipocyte fatty acid binding protein and perilipin on mRNA and protein levels. Adiponectin expression was post-transcriptionally down-regulated in the absence of rosiglitazone. Insulin sensitivity as measured by insulin-induced phosphorylation of Akt and S6 ribosomal protein was also independent of rosiglitazone. In addition to commonly used adipogenic markers, we investigated further PPARgamma-stimulated proteins with a role in lipid metabolism. We observed an increase of lipoprotein receptor (VLDLR, LRP1) and apolipoprotein E expression during differentiation. Despite this increased expression, the receptor-mediated endocytosis of lipoproteins was decreased in differentiated adipocytes, suggesting that these proteins may have an additional function in adipose tissue beyond lipoprotein uptake.

  2. Reversal of hyperglycemia in mice by using human expandable insulin-producing cells differentiated from fetal liver progenitor cells

    Science.gov (United States)

    Zalzman, Michal; Gupta, Sanjeev; Giri, Ranjit K.; Berkovich, Irina; Sappal, Baljit S.; Karnieli, Ohad; Zern, Mark A.; Fleischer, Norman; Efrat, Shimon

    2003-06-01

    Beta-cell replacement is considered to be the most promising approach for treatment of type 1 diabetes. Its application on a large scale is hindered by a shortage of cells for transplantation. Activation of insulin expression, storage, and regulated secretion in stem/progenitor cells offers novel ways to overcome this shortage. We explored whether fetal human progenitor liver cells (FH) could be induced to differentiate into insulin-producing cells after expression of the pancreatic duodenal homeobox 1 (Pdx1) gene, which is a key regulator of pancreatic development and insulin expression in beta cells. FH cells possess a considerable replication capacity, and this was further extended by introduction of the gene for the catalytic subunit of human telomerase. Immortalized FH cells expressing Pdx1 activated multiple beta-cell genes, produced and stored considerable amounts of insulin, and released insulin in a regulated manner in response to glucose. When transplanted into hyperglycemic immunodeficient mice, the cells restored and maintained euglycemia for prolonged periods. Quantitation of human C-peptide in the mouse serum confirmed that the glycemia was normalized by the transplanted human cells. This approach offers the potential of a novel source of cells for transplantation into patients with type 1 diabetes.

  3. Beta-cell dysfunction and low insulin clearance in insulin-resistant human immunodeficiency virus (HIV)-infected patients with lipodystrophy

    DEFF Research Database (Denmark)

    Haugaard, Steen B; Andersen, Ove; Vølund, Aage;

    2005-01-01

    with insulin sensitivity) and insulin clearance rate were reduced in lipodystrophic patients (-55%, P clearance rate correlated strongly with insulin sensitivity (r = 0.82, P ... and diabetes mellitus (63%vs. 20%, P clearance....

  4. Lifelong Physical Activity Prevents Aging-Associated Insulin Resistance in Human Skeletal Muscle Myotubes via Increased Glucose Transporter Expression.

    Directory of Open Access Journals (Sweden)

    Tipwadee Bunprajun

    Full Text Available Both aging and physical inactivity are associated with increased development of insulin resistance whereas physical activity has been shown to promote increased insulin sensitivity. Here we investigated the effects of physical activity level on aging-associated insulin resistance in myotubes derived from human skeletal muscle satellite cells. Satellite cells were obtained from young (22 yrs normally active or middle-aged (56.6 yrs individuals who were either lifelong sedentary or lifelong active. Both middle-aged sedentary and middle-aged active myotubes had increased p21 and myosin heavy chain protein expression. Interestingly MHCIIa was increased only in myotubes from middle-aged active individuals. Middle-aged sedentary cells had intact insulin-stimulated Akt phosphorylation however, the same cell showed ablated insulin-stimulated glucose uptake and GLUT4 translocation to the plasma membrane. On the other hand, middle-aged active cells retained both insulin-stimulated increases in glucose uptake and GLUT4 translocation to the plasma membrane. Middle-aged active cells also had significantly higher mRNA expression of GLUT1 and GLUT4 compared to middle-aged sedentary cells, and significantly higher GLUT4 protein. It is likely that physical activity induces a number of stable adaptations, including increased GLUT4 expression that are retained in cells ex vivo and protect, or delay the onset of middle-aged-associated insulin resistance. Additionally, a sedentary lifestyle has an impact on the metabolism of human myotubes during aging and may contribute to aging-associated insulin resistance through impaired GLUT4 localization.

  5. [Association of the insulin-like growth factor II (IGF2) gene with human cognitive functions].

    Science.gov (United States)

    Alfimova, M V; Lezheĭko, T V; Gritsenko, I K; Golimbet, V E

    2012-08-01

    Active search for candidate genes whose polymorphisms are associated with human cognitive functions has been in progress in the past years. The study focused on the role that the insulin-like growth factor II (IGF2) gene may play in the variation of cognitive processes related to executive functions. The ApaI polymorphism of the IGF2 gene was tested for association with selective attention during visual search, working memory/mental control, and semantic verbal fluency in a group of 182 healthy individuals. The ApaI polymorphism was associated with the general cognitive index and selective attention measure. Carriers of genotype AA displayed higher values of the two parameters than carriers of genotype GG. It was assumed that the ApaI polymorphism of the IGF2 gene influences the human cognitive functions, acting possibly via modulation of the IGF-II level in the central nervous system.

  6. Evidence that phosphatidylcholine-specific phospholipase C is a key molecule mediating insulin-induced enhancement of gene expression from human cytomegalovirus promoter in CHO cells

    OpenAIRE

    Zhang, Yingpei; Katakura, Yoshinori; Seto, Perry; Shirahata, Sanetaka

    1997-01-01

    The signal transduction from insulin to its receptors and Ras has been extensively studied, while little has been reported beyond these steps. We found that the expression of human interleukin 6 gene under the control of immediate early gene promoter of human cytomegalovirus was enhanced by insulin sitmulation in Chinese hamster ovary cells. The induction effect of insulin was not significantly affected by inhibitors or activators of conventional protein kinase C, cAMP dependent protein kinas...

  7. Insulin Resistance after a 72 hour Fast is Associated with Impaired AS160 Phosphorylation and Accumulation of Lipid and Glycogen in Human Skeletal Muscle

    DEFF Research Database (Denmark)

    Vendelbo, Mikkel Holm; Clasen, Berthil F F; Treebak, Jonas T;

    2012-01-01

    During fasting, human skeletal muscle depends on lipid oxidation for its energy substrate metabolism. This is associated with the development of insulin resistance and a subsequent reduction of insulin-stimulated glucose uptake. The underlying mechanisms controlling insulin action on skeletal...... of AMPK or insulin regulation of Akt, both of which are established upstream kinases of AS160. These findings show that insulin resistance in muscles from healthy individuals is associated with suppression of site-specific phosphorylation of AS160, without Akt or AMPK being affected. This impairment of AS...

  8. Effect of insulin on human skeletal muscle mitochondrial ATP production, protein synthesis, and mRNA transcripts

    Science.gov (United States)

    Stump, Craig S.; Short, Kevin R.; Bigelow, Maureen L.; Schimke, Jill M.; Sreekumaran Nair, K.

    2003-06-01

    Mitochondria are the primary site of skeletal muscle fuel metabolism and ATP production. Although insulin is a major regulator of fuel metabolism, its effect on mitochondrial ATP production is not known. Here we report increases in vastus lateralis muscle mitochondrial ATP production capacity (32-42%) in healthy humans (P oxidative phosphorylation in skeletal muscle along with synthesis of gene transcripts and mitochondrial protein in human subjects. Skeletal muscle of type 2 diabetic patients has a reduced capacity to increase ATP production with high insulin levels. cytochrome c oxidase | NADH dehydrogenase subunit IV | amino acids | citrate synthase

  9. Cycle modulation of insulin-like growth factor-binding protein 1 in human endometrium

    Directory of Open Access Journals (Sweden)

    Corleta H.

    2000-01-01

    Full Text Available Endometrium is one of the fastest growing human tissues. Sex hormones, estrogen and progesterone, in interaction with several growth factors, control its growth and differentiation. Insulin-like growth factor 1 (IGF-1 interacts with cell surface receptors and also with specific soluble binding proteins. IGF-binding proteins (IGF-BP have been shown to modulate IGF-1 action. Of six known isoforms, IGF-BP-1 has been characterized as a marker produced by endometrial stromal cells in the late secretory phase and in the decidua. In the current study, IGF-1-BP concentration and affinity in the proliferative and secretory phase of the menstrual cycle were measured. Endometrial samples were from patients of reproductive age with regular menstrual cycles and taking no steroid hormones. Cytosolic fractions were prepared and binding of 125I-labeled IGF-1 performed. Cross-linking reaction products were analyzed by SDS-polyacrylamide gel electrophoresis (7.5% followed by autoradiography. 125I-IGF-1 affinity to cytosolic proteins was not statistically different between the proliferative and secretory endometrium. An approximately 35-kDa binding protein was identified when 125I-IGF-1 was cross-linked to cytosol proteins. Secretory endometrium had significantly more IGF-1-BP when compared to proliferative endometrium. The specificity of the cross-linking process was evaluated by the addition of 100 nM unlabeled IGF-1 or insulin. Unlabeled IGF-1 totally abolished the radioactivity from the band, indicating specific binding. Insulin had no apparent effect on the intensity of the labeled band. These results suggest that IGF-BP could modulate the action of IGF-1 throughout the menstrual cycle. It would be interesting to study this binding protein in other pathologic conditions of the endometrium such as adenocarcinomas and hyperplasia.

  10. 门冬胰岛素30治疗初发2型糖尿病的皮下注射方案比较%Different injection frequency with biphasic insulin aspart 30 for newly diagnosed type 2 diabetes

    Institute of Scientific and Technical Information of China (English)

    马波; 李红涛; 王晓东; 包春艳; 李春进; 吴书元; 杨涛

    2012-01-01

    Objective To observe the efficacy of bid and tid biphasic insulin aspart 30(BIAsp30) in patients with type 2 diabetes. Methods A quasi-randomized controlled trial was performed in 73 newly diagnosed patients with type 2 diabetes. They were divided into group A (BIAsp30, subcutaneous injection, bid) and group B (BIAsp30, subcutaneous injection, tid). The effect of changes in fasting plasma glucose(FPG), postprandial blood glucose(PBG), HbAlc and the rate of hypoglycemia were analyzed. Results Afer three months treatment, the glucose level was decreased significantly in both groups. The levels of blood glucose (after breakfast, after lunch, before dinner and after dinner) in group B were lower than those in group A.The level of PBG and the rate of hypoglycemia in group B were lower than those in group A significantly. Conclusion BIAsp30(subcutaneous injection, tid) is effective and safe in the treatment of newly diagnosed type 2 diabetes patients.%目的 观察门冬胰岛素30(BIAsp30)一日2次和3次皮下注射方案对初诊2型糖尿病患者的疗效.方法 73例初诊2型糖尿病患者按半随机原则分为A组和B组,A组予BIAsp30一日2次皮下注射,B组予BIAsp30一日3次皮下注射,观察两组患者空腹血糖(FPG)、餐后血糖(PBG)、糖化血红蛋白(HbA1c)及低血糖发生率的差异等.结果 与治疗前相比,治疗3个月两组患者血糖水平均显著降低,且治疗后B组早餐后、午餐后、晚餐前及晚餐后血糖水平均低于A组;同时B组PBG水平显著低于A组;B组低血糖发生率也低于A组.结论 门冬胰岛素30一日3次治疗初诊2型糖尿病患者疗效显著,安全性高.

  11. Reevaluation of Fatty Acid Receptor 1 as a Drug Target for the Stimulation of Insulin Secretion in Humans

    Science.gov (United States)

    Wagner, Robert; Kaiser, Gabriele; Gerst, Felicia; Christiansen, Elisabeth; Due-Hansen, Maria E.; Grundmann, Manuel; Machicao, Fausto; Peter, Andreas; Kostenis, Evi; Ulven, Trond; Fritsche, Andreas; Häring, Hans-Ulrich; Ullrich, Susanne

    2013-01-01

    The role of free fatty acid receptor 1 (FFAR1/GPR40) in glucose homeostasis is still incompletely understood. Small receptor agonists stimulating insulin secretion are undergoing investigation for the treatment of type 2 diabetes. Surprisingly, genome-wide association studies did not discover diabetes risk variants in FFAR1. We reevaluated the role of FFAR1 in insulin secretion using a specific agonist, FFAR1-knockout mice and human islets. Nondiabetic individuals were metabolically phenotyped and genotyped. In vitro experiments indicated that palmitate and a specific FFAR1 agonist, TUG-469, stimulate glucose-induced insulin secretion through FFAR1. The proapoptotic effect of chronic exposure of β-cells to palmitate was independent of FFAR1. TUG-469 was protective, whereas inhibition of FFAR1 promoted apoptosis. In accordance with the proapoptotic effect of palmitate, in vivo cross-sectional observations demonstrated a negative association between fasting free fatty acids (NEFAs) and insulin secretion. Because NEFAs stimulate secretion through FFAR1, we examined the interaction of genetic variation in FFAR1 with NEFA and insulin secretion. The inverse association of NEFA and secretion was modulated by rs1573611 and became steeper for carriers of the minor allele. In conclusion, FFAR1 agonists support β-cell function, but variation in FFAR1 influences NEFA effects on insulin secretion and therefore could affect therapeutic efficacy of FFAR1 agonists. PMID:23378609

  12. Application of simple fed-batch technique to high-level secretory production of insulin precursor using Pichia pastoris with subsequent purification and conversion to human insulin

    Directory of Open Access Journals (Sweden)

    Chugh Dipti

    2010-05-01

    Full Text Available Abstract Background The prevalence of diabetes is predicted to rise significantly in the coming decades. A recent analysis projects that by the year 2030 there will be ~366 million diabetics around the world, leading to an increased demand for inexpensive insulin to make this life-saving drug also affordable for resource poor countries. Results A synthetic insulin precursor (IP-encoding gene, codon-optimized for expression in P. pastoris, was cloned in frame with the Saccharomyces cerevisiae α-factor secretory signal and integrated into the genome of P. pastoris strain X-33. The strain was grown to high-cell density in a batch procedure using a defined medium with low salt and high glycerol concentrations. Following batch growth, production of IP was carried out at methanol concentrations of 2 g L-1, which were kept constant throughout the remaining production phase. This robust feeding strategy led to the secretion of ~3 gram IP per liter of culture broth (corresponding to almost 4 gram IP per liter of cell-free culture supernatant. Using immobilized metal ion affinity chromatography (IMAC as a novel approach for IP purification, 95% of the secreted product was recovered with a purity of 96% from the clarified culture supernatant. Finally, the purified IP was trypsin digested, transpeptidated, deprotected and further purified leading to ~1.5 g of 99% pure recombinant human insulin per liter of culture broth. Conclusions A simple two-phase cultivation process composed of a glycerol batch and a constant methanol fed-batch phase recently developed for the intracellular production of the Hepatitis B surface antigen was adapted to secretory IP production. Compared to the highest previously reported value, this approach resulted in an ~2 fold enhancement of IP production using Pichia based expression systems, thus significantly increasing the efficiency of insulin manufacture.

  13. Stimulation tests of human growth hormone secretion by insulin, lysine vasopressin, pyrogen and glucagon

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    Ogawa,Norio

    1974-06-01

    Full Text Available Firstly, comparisons have been made of the secretion of human growth hormone (HGH that was induced by insulin, lysine vasopressin and pyrogen injections in order to study whether these substances can be utilized as a rapid test of HGH secretion. In insulin test, a fall of the fasting blood glucose level by 28.6% or more seemed to be sufficient to provoke adequate HGH elevation, and 9.4 ng/ml or higher HGH increment was recognized as being normal, because lysine vasopressin and pyrogen produce varying degrees of side-effects and are less specific and unpredictable in the release of HGH. Secondly, the pharmacologic effects and mechanism of action of exogenous glucagon upon the HGH secretion were studied. In normal subjects after one mg sc glucagon, there was a mean peak blood glucose level of 142. 4±3.l mg/lOO ml at 30 min, HGH levels reached a mean peak level of 22. 6±4. 8 ng/ml at 150 min, and no false negative response was noted. In patients with hypopituitarism, there was no positive response in plasma HGH levels after the sc glucagon. The present study revealed that the rise and subsequent fall of blood glucose are not the sole mechanism responsible for the effct of glucagon on HGH secretion, and that the HGH secretion in response to the sc glucagon was not triggered by cathecholamine via the stimulation of the adrenal medulla.

  14. MicroRNA-223 Expression Is Upregulated in Insulin Resistant Human Adipose Tissue

    Directory of Open Access Journals (Sweden)

    Tung-Yueh Chuang

    2015-01-01

    Full Text Available MicroRNAs (miRNAs are short noncoding RNAs involved in posttranscriptional regulation of gene expression and influence many cellular functions including glucose and lipid metabolism. We previously reported that adipose tissue (AT from women with polycystic ovary syndrome (PCOS or controls with insulin resistance (IR revealed a differentially expressed microRNA (miRNA profile, including upregulated miR-93 in PCOS patients and in non-PCOS women with IR. Overexpressed miR-93 directly inhibited glucose transporter isoform 4 (GLUT4 expression, thereby influencing glucose metabolism. We have now studied the role of miR-223, which is also abnormally expressed in the AT of IR subjects. Our data indicates that miR-223 is significantly overexpressed in the AT of IR women, regardless of whether they had PCOS or not. miR-223 expression in AT was positively correlated with HOMA-IR. Unlike what is reported in cardiomyocytes, overexpression of miR-223 in human differentiated adipocytes was associated with a reduction in GLUT4 protein content and insulin-stimulated glucose uptake. In addition, our data suggests miR-223 regulates GLUT4 expression by direct binding to its 3′ untranslated region (3′UTR. In conclusion, in AT miR-223 is an IR-related miRNA that may serve as a potential therapeutic target for the treatment of IR-related disorders.

  15. Calcification of human vascular smooth muscle cells: associations with osteoprotegerin expression and acceleration by high-dose insulin

    DEFF Research Database (Denmark)

    Olesen, Ping; Knudsen, Kirsten Quyen Nguyen; Wogensen, Lise

    2007-01-01

    Arterial medial calcifications occur often in diabetic individuals as part of the diabetic macroangiopathy. The pathogenesis is unknown, but the presence of calcifications predicts risk of cardiovascular events. We examined the effects of insulin on calcifying smooth muscle cells in vitro...... and measured the expression of the bone-related molecule osteoprotegerin (OPG). Human vascular smooth muscle cells (VSMCs) were grown from aorta from kidney donors. Induction of calcification was performed with beta-glycerophosphate. The influence of insulin (200 microU/ml or 1,000 microU/ml) on calcification...... calcification in human smooth muscle cells from a series of donors after variable time in culture. Decreased OPG amounts were observed from the cells during the accelerated calcification phase. High dose of insulin (1,000 microU/ml) accelerated the calcification, whereas lower concentrations (200 microU/ml) did...

  16. Insulin-like growth factors, insulin-like growth factor-binding proteins, insulin-like growth factor-binding protein-3 protease, and growth hormone-binding protein in lipodystrophic human immunodeficiency virus-infected patients

    DEFF Research Database (Denmark)

    Haugaard, Steen B; Andersen, Ove; Hansen, Birgitte R;

    2004-01-01

    Human immunodeficiency virus (HIV)-lipodystrophy is associated with impaired growth hormone (GH) secretion. It remains to be elucidated whether insulin-like growth factors (IGFs), IGF-binding proteins (IGFBPs), IGFBP-3 protease, and GH-binding protein (GHBP) are abnormal in HIV-lipodystrophy. The......Human immunodeficiency virus (HIV)-lipodystrophy is associated with impaired growth hormone (GH) secretion. It remains to be elucidated whether insulin-like growth factors (IGFs), IGF-binding proteins (IGFBPs), IGFBP-3 protease, and GH-binding protein (GHBP) are abnormal in HIV......-lipodystrophy. These parameters were measured in overnight fasting serum samples from 16 Caucasian males with HIV-lipodystrophy (LIPO) and 15 Caucasian HIV-infected males without lipodystrophy (NONLIPO) matched for age, weight, duration of HIV infection, and antiretroviral therapy. In LIPO, abdominal fat mass and insulin...... study groups, including suppressed GH, and increased GHBP in LIPO, argue against GH resistance of GH-sensitive tissues in LIPO compared with NONLIPO; however, this notion awaits examination in dose-response studies. Furthermore, our data suggest that IGFBP-3 protease is a significant regulator...

  17. The effect of 30 months of low-dose replacement therapy with recombinant human growth hormone (rhGH) on insulin and C-peptide kinetics, insulin secretion, insulin sensitivity, glucose effectiveness, and body composition in GH-deficient adults

    DEFF Research Database (Denmark)

    Rosenfalck, A M; Maghsoudi, S; Fisker, S;

    2000-01-01

    (frequently sampled iv glucose tolerance test) glucose tolerance test, and body composition was estimated by dual-energy x-ray absorptiometry. Treatment with rhGH induced persistent favorable changes in body composition, with a 10% increase in lean body mass (P ...The aim of the present study was to evaluate the long-term (30 months) metabolic effects of recombinant human GH (rhGH) given in a mean dose of 6.7 microg/kg x day (= 1.6 IU/day), in 11 patients with adult GH deficiency. Glucose metabolism was evaluated by an oral glucose tolerance test and an iv...... in glucose tolerance, beta-cell response was still inappropriate. Our conclusion is that long-term rhGH-replacement therapy in GH deficiency adults induced a significant deterioration in glucose tolerance, profound changes in kinetics of C-peptide, and insulin and prehepatic insulin secretion, despite...

  18. mTOR inhibition with rapamycin causes impaired insulin signalling and glucose uptake in human subcutaneous and omental adipocytes.

    Science.gov (United States)

    Pereira, Maria J; Palming, Jenny; Rizell, Magnus; Aureliano, Manuel; Carvalho, Eugénia; Svensson, Maria K; Eriksson, Jan W

    2012-05-15

    Rapamycin is an immunosuppressive agent used after organ transplantation, but its molecular effects on glucose metabolism needs further evaluation. We explored rapamycin effects on glucose uptake and insulin signalling proteins in adipocytes obtained via subcutaneous (n=62) and omental (n=10) fat biopsies in human donors. At therapeutic concentration (0.01 μM) rapamycin reduced basal and insulin-stimulated glucose uptake by 20-30%, after short-term (15 min) or long-term (20 h) culture of subcutaneous (n=23 and n=10) and omental adipocytes (n=6 and n=7). Rapamycin reduced PKB Ser473 and AS160 Thr642 phosphorylation, and IRS2 protein levels in subcutaneous adipocytes. Additionally, it reduced mTOR-raptor, mTOR-rictor and mTOR-Sin1 interactions, suggesting decreased mTORC1 and mTORC2 formation. Rapamycin also reduced IR Tyr1146 and IRS1 Ser307/Ser616/Ser636 phosphorylation, whereas no effects were observed on the insulin stimulated IRS1-Tyr and TSC2 Thr1462 phosphorylation. This is the first study to show that rapamycin reduces glucose uptake in human adipocytes through impaired insulin signalling and this may contribute to the development of insulin resistance associated with rapamycin therapy.

  19. Human ketone body production and utilization studied using tracer techniques: Regulation by free fatty acids, insulin, catecholamines, and thyroid hormones

    Energy Technology Data Exchange (ETDEWEB)

    Keller, U.; Lustenberger, M.; Mueller-Brand, J.G.; Gerber, P.P.; Stauffacher, W.

    1989-05-01

    Ketone body concentrations fluctuate markedly during physiological and pathological conditions. Tracer techniques have been developed in recent years to study production, utilization, and the metabolic clearance rate of ketone bodies. This review describes data on the roles of insulin, catecholamines, and thyroid hormones in the regulation of ketone body kinetics. The data indicate that insulin lowers ketone body concentrations by three independent mechanisms: first, it inhibits lipolysis, and thus lowers free fatty acid availability for ketogenesis; second, it restrains ketone body production within the liver; third, it enhances peripheral ketone body utilization. To assess these effects in humans in vivo, experimental models were developed to study insulin effects with controlled concentrations of free fatty acids, insulin, glucagon, and ketone bodies. Presently available data also support an important role of catecholamines in increasing ketone body concentrations. Evidence was presented that norepinephrine increases ketogenesis not only by stimulating lipolysis, and thus releasing free fatty acids, but also by increasing intrahepatic ketogenesis. Thyroid hormone availability was associated with lipolysis and ketogenesis. Ketone body concentrations after an overnight fast were only modestly elevated in hyperthyroidism resulting from increased peripheral ketone body clearance. There was a significant correlation between serum triiodothyronine levels and the ketone body metabolic clearance rate. Thus, ketone body homeostasis in human subjects resulted from the interaction of hormones such as insulin, catecholamines, and thyroid hormones regulating lipolysis, intrahepatic ketogenesis, and peripheral ketone body utilization. 58 references.

  20. Characterisation of adiponectin multimers and the IGF axis in humans with a heterozygote mutation in the tyrosine kinase domain of the insulin receptor gene

    DEFF Research Database (Denmark)

    Højlund, Kurt; Beck-Nielsen, Henning; Flyvbjerg, Allan;

    2012-01-01

    Objective: Low levels of adiponectin, IGF-binding protein (IGFBP)-1, and IGFBP-2, and high levels of leptin correlate with several indices of insulin resistance and risk of type 2 diabetes. However, in insulin receptoropathies plasma adiponectin is paradoxically increased despite severe insulin r...... in insulin receptor deficient individuals.......Objective: Low levels of adiponectin, IGF-binding protein (IGFBP)-1, and IGFBP-2, and high levels of leptin correlate with several indices of insulin resistance and risk of type 2 diabetes. However, in insulin receptoropathies plasma adiponectin is paradoxically increased despite severe insulin...... resistance, whereas the IGF-axis is sparsely described. Here, we aimed to characterize the multimeric distribution of adiponectin and the IGF-axis in humans with a heterozygous INSR mutation (Arg1174Gln).Methods: Blood samples obtained in six Arg1174Gln-carriers and 10 lean, healthy controls before and after...

  1. Crystal structure of human insulin-regulated aminopeptidase with specificity for cyclic peptides.

    Science.gov (United States)

    Hermans, Stefan J; Ascher, David B; Hancock, Nancy C; Holien, Jessica K; Michell, Belinda J; Chai, Siew Yeen; Morton, Craig J; Parker, Michael W

    2015-02-01

    Insulin-regulated aminopeptidase (IRAP or oxytocinase) is a membrane-bound zinc-metallopeptidase that cleaves neuroactive peptides in the brain and produces memory enhancing effects when inhibited. We have determined the crystal structure of human IRAP revealing a closed, four domain arrangement with a large, mostly buried cavity abutting the active site. The structure reveals that the GAMEN exopeptidase loop adopts a very different conformation from other aminopeptidases, thus explaining IRAP's unique specificity for cyclic peptides such as oxytocin and vasopressin. Computational docking of a series of IRAP-specific cognitive enhancers into the crystal structure provides a molecular basis for their structure-activity relationships and demonstrates that the structure will be a powerful tool in the development of new classes of cognitive enhancers for treating a variety of memory disorders such as Alzheimer's disease.

  2. Cost-effectiveness of biphasic insulin aspart 30 combined with metformin in patients with type 2 diabetes mellitus%双时相门冬胰岛素联用二甲双胍治疗2型糖尿病的成本-效果分析

    Institute of Scientific and Technical Information of China (English)

    李洪超; 徐菲; 王藩

    2011-01-01

    Objectives; To evaluate the long-term cost-effectiveness of switching from basal insulin to bi-phasic insulin aspart 30 ( BIAsp30) in patients with type 2 diabetes mellitus (T2DM) in China. Methods: A published and validated computer simulation model of diabetes (CORE Diabetes Model) was used to project long-term (30 years) of health and economic outcomes. Simulated cohorts and treatment effects were derived from a 16-week, multi-centre, and single-arm trial-NCT00669864, which investigated the efficacy and safety of BIAsp30Chinese Journal of New Drugs 2011,20(21)+ / - metformin in T2DM patients inadequately controlled with basal insulin. Two subgroups of basal insulin treatment were categorized as insulin glargine (Iglar) +/ - metformin and neutral protamine hagedorn (NPH) insulin+ / - metformin. The market retail prices of medications were calculated to estimate treatment costs. The diabetes management and complication costs were obtained from the published data in China. An annual discounting rate of 3% was used for both costs and health outcomes. One-way sensitivity analysis was performed. Results; Therapy conversion to BIAsp30 was projected to improve life expectancy significantly in comparison with Iglar (0.347 ± 0.245) years and NPH (0.452 ±0.242) years. Transfer to BIAsp30 was associated with improvements in 0.327 quality-adjusted life years (QALY) over Iglar, and 0.393 QALYs over NPH. Therapy conversion to BIAsp30 reduced medical costs by Chinese Yuan (CNY) 46 540 per patient compared to Iglar. However, it increased CNY 19 525 compared to NPH, and was associated with an incremental cost-effectiveness ratio (ICER) of CNY 49 730 per QALY gained. Conclusion; Therapy conversion from basal insulin to BIAsp30 in T2DM patients in China is associated with improvements in life expectancy and QALYs. Transfer to BIAsp30 is cost-saving treatment strategy in T2DM patients managed with Iglar, and the cost-effective in T2DM patients managed with NPH would be considered

  3. Effect of Sfrp5 on cytokine release and insulin action in primary human adipocytes and skeletal muscle cells.

    Directory of Open Access Journals (Sweden)

    Maren Carstensen

    Full Text Available Secreted frizzled-related protein 5 (Sfrp5 is an adipokine with anti-inflammatory and insulin-sensitizing properties in mice. However, the mechanism of Sfrp5 action, especially in humans, is largely unknown. Therefore, cytokine release and insulin signaling were analyzed to investigate the impact of Sfrp5 on inflammation and insulin signaling in primary human adipocytes and skeletal muscle cells (hSkMC. Sfrp5 neither affected interleukin (IL-6, monocyte chemoattractant protein-1 (MCP-1 and adiponectin release from human adipocytes, nor IL-6 and IL-8 release from hSkMC. In tumor necrosis factor (TNF α-treated adipocytes, Sfrp5 reduced IL-6 release by 49% (p<0.05, but did not affect MCP-1 and adiponectin release. In MCP-1-treated hSkMC, Sfrp5 did not affect cytokine secretion. In untreated adipocytes, Sfrp5 decreased the insulin-mediated phosphorylation of Akt-Ser473, Akt-Thr308, GSK3α-Ser21 and PRAS40-Thr246 by 34% (p<0.01, 31% (p<0.05, 37% (p<0.05 and 34% (p<0.01, respectively, and the stimulation of glucose uptake by 25% (p<0.05. Incubation with TNFα increased the phosphorylation of JNK and NFκB, and impaired insulin signaling. When Sfrp5 and TNFα were combined, there was no additional effect on insulin signaling and JNK phosphorylation, but phosphorylation of NFκB was reversed to basal levels. Sfrp5 had no effect on insulin signaling in untreated or in MCP-1 treated hSkMC. Thus, Sfrp5 lowered IL-6 release and NFκB phosphorylation in cytokine-treated human adipocytes, but not under normal conditions, and decreased insulin signaling in untreated human adipocytes. Sfrp5 did not act on hSkMC. Therefore, the cellular actions of Sfrp5 seem to depend on the type of tissue as well as its inflammatory and metabolic state.

  4. Effect of Sfrp5 on Cytokine Release and Insulin Action in Primary Human Adipocytes and Skeletal Muscle Cells

    Science.gov (United States)

    Röhrig, Karin; Fahlbusch, Pia; Roden, Michael; Herder, Christian; Ouwens, D. Margriet

    2014-01-01

    Secreted frizzled-related protein 5 (Sfrp5) is an adipokine with anti-inflammatory and insulin-sensitizing properties in mice. However, the mechanism of Sfrp5 action, especially in humans, is largely unknown. Therefore, cytokine release and insulin signaling were analyzed to investigate the impact of Sfrp5 on inflammation and insulin signaling in primary human adipocytes and skeletal muscle cells (hSkMC). Sfrp5 neither affected interleukin (IL)-6, monocyte chemoattractant protein-1 (MCP-1) and adiponectin release from human adipocytes, nor IL-6 and IL-8 release from hSkMC. In tumor necrosis factor (TNF) α-treated adipocytes, Sfrp5 reduced IL-6 release by 49% (p<0.05), but did not affect MCP-1 and adiponectin release. In MCP-1-treated hSkMC, Sfrp5 did not affect cytokine secretion. In untreated adipocytes, Sfrp5 decreased the insulin-mediated phosphorylation of Akt-Ser473, Akt-Thr308, GSK3α-Ser21 and PRAS40-Thr246 by 34% (p<0.01), 31% (p<0.05), 37% (p<0.05) and 34% (p<0.01), respectively, and the stimulation of glucose uptake by 25% (p<0.05). Incubation with TNFα increased the phosphorylation of JNK and NFκB, and impaired insulin signaling. When Sfrp5 and TNFα were combined, there was no additional effect on insulin signaling and JNK phosphorylation, but phosphorylation of NFκB was reversed to basal levels. Sfrp5 had no effect on insulin signaling in untreated or in MCP-1 treated hSkMC. Thus, Sfrp5 lowered IL-6 release and NFκB phosphorylation in cytokine-treated human adipocytes, but not under normal conditions, and decreased insulin signaling in untreated human adipocytes. Sfrp5 did not act on hSkMC. Therefore, the cellular actions of Sfrp5 seem to depend on the type of tissue as well as its inflammatory and metabolic state. PMID:24465779

  5. Adsorption of human insulin on single-crystal gold surfaces investigated by in situ scanning tunnelling microscopy and electrochemistry

    DEFF Research Database (Denmark)

    Welinder, Anna Christina; Zhang, Jingdong; Steensgaard, D.B.;

    2010-01-01

    We have explored the adsorption of zinc-free human insulin on the three low-index single-crystalline Au(111)-, Au(100)- and Au(110)-surfaces in aqueous buffer (KH2PO4, pH 5) by a combination of electrochemical scanning tunnelling microscopy (in situ STM) at single-molecule resolution and linear s...

  6. Long-term tolerability of inhaled human insulin (Exubera) in patients with poorly controlled type 2 diabetes

    DEFF Research Database (Denmark)

    Barnett, A H; Lange, P; Dreyer, M;

    2007-01-01

    OBJECTIVE: Inhaled human insulin (Exubera; EXU) has shown encouraging tolerability in short-term trials. We evaluated the safety profile of EXU after long-term exposure. DESIGN: In two, open-label, 2-year studies patients poorly controlled on a sulphonylurea were randomised to adjunctive EXU or m...

  7. Angiopoietin-Like Protein 4 is Differentially Regulated by Glucocorticoids and Insulin in vitro and in vivo in Healthy Humans

    NARCIS (Netherlands)

    Raalte, D.H. van; Brands, M.; Serlie, M.J.; Mudde, K.; Stienstra, R.; Sauerwein, H.P.; Kersten, S.; Diamant, M.

    2012-01-01

    Angiopoietin-like protein 4 (Angptl4) is a circulating inhibitor of plasma triglyceride clearance via inhibition of lipoprotein lipase. The aim of the present study was to examine the regulation of Angptl4 by glucocorticoids and insulin in vivo in humans, since these factors regulate Angptl4 express

  8. Changes in glucose tolerance and insulin sensitivity following 2 weeks of daily cinnamon ingestion in healthy humans

    DEFF Research Database (Denmark)

    Solomon, Thomas; Blannin, Andrew K

    2009-01-01

    Cinnamon can improve fasting glucose in humans yet data on insulin sensitivity are limited and controversial. Eight male volunteers (aged 25 +/- 1 years, body mass 76.5 +/- 3.0 kg, BMI 24.0 +/- 0.7 kg m(-2); mean +/- SEM) underwent two 14-day interventions involving cinnamon or placebo supplement...

  9. Lipodystrophy in human immunodeficiency virus patients impairs insulin action and induces defects in beta-cell function

    DEFF Research Database (Denmark)

    Andersen, Ove; Haugaard, Steen B; Andersen, Ulrik B;

    2003-01-01

    The pathophysiology of insulin resistance in human immunodeficiency virus (HIV)-associated lipodystrophy syndrome (HALS) is not fully clarified. We investigated 18 men with HALS and 18 HIV-positive males without lipodystrophy (control subjects). Duration and modality of antiretroviral therapy were...

  10. Glucose Homeostatic Law: Insulin Clearance Predicts the Progression of Glucose Intolerance in Humans.

    Directory of Open Access Journals (Sweden)

    Kaoru Ohashi

    Full Text Available Homeostatic control of blood glucose is regulated by a complex feedback loop between glucose and insulin, of which failure leads to diabetes mellitus. However, physiological and pathological nature of the feedback loop is not fully understood. We made a mathematical model of the feedback loop between glucose and insulin using time course of blood glucose and insulin during consecutive hyperglycemic and hyperinsulinemic-euglycemic clamps in 113 subjects with variety of glucose tolerance including normal glucose tolerance (NGT, impaired glucose tolerance (IGT and type 2 diabetes mellitus (T2DM. We analyzed the correlation of the parameters in the model with the progression of glucose intolerance and the conserved relationship between parameters. The model parameters of insulin sensitivity and insulin secretion significantly declined from NGT to IGT, and from IGT to T2DM, respectively, consistent with previous clinical observations. Importantly, insulin clearance, an insulin degradation rate, significantly declined from NGT, IGT to T2DM along the progression of glucose intolerance in the mathematical model. Insulin clearance was positively correlated with a product of insulin sensitivity and secretion assessed by the clamp analysis or determined with the mathematical model. Insulin clearance was correlated negatively with postprandial glucose at 2h after oral glucose tolerance test. We also inferred a square-law between the rate constant of insulin clearance and a product of rate constants of insulin sensitivity and secretion in the model, which is also conserved among NGT, IGT and T2DM subjects. Insulin clearance shows a conserved relationship with the capacity of glucose disposal among the NGT, IGT and T2DM subjects. The decrease of insulin clearance predicts the progression of glucose intolerance.

  11. Acute Biphasic Effects of Ayahuasca.

    Directory of Open Access Journals (Sweden)

    Eduardo Ekman Schenberg

    Full Text Available Ritual use of ayahuasca, an amazonian Amerindian medicine turned sacrament in syncretic religions in Brazil, is rapidly growing around the world. Because of this internationalization, a comprehensive understanding of the pharmacological mechanisms of action of the brew and the neural correlates of the modified states of consciousness it induces is important. Employing a combination of electroencephalogram (EEG recordings and quantification of ayahuasca's compounds and their metabolites in the systemic circulation we found ayahuasca to induce a biphasic effect in the brain. This effect was composed of reduced power in the alpha band (8-13 Hz after 50 minutes from ingestion of the brew and increased slow- and fast-gamma power (30-50 and 50-100 Hz, respectively between 75 and 125 minutes. Alpha power reductions were mostly located at left parieto-occipital cortex, slow-gamma power increase was observed at left centro-parieto-occipital, left fronto-temporal and right frontal cortices while fast-gamma increases were significant at left centro-parieto-occipital, left fronto-temporal, right frontal and right parieto-occipital cortices. These effects were significantly associated with circulating levels of ayahuasca's chemical compounds, mostly N,N-dimethyltryptamine (DMT, harmine, harmaline and tetrahydroharmine and some of their metabolites. An interpretation based on a cognitive and emotional framework relevant to the ritual use of ayahuasca, as well as it's potential therapeutic effects is offered.

  12. Acute Biphasic Effects of Ayahuasca

    Science.gov (United States)

    Schenberg, Eduardo Ekman; Alexandre, João Felipe Morel; Filev, Renato; Cravo, Andre Mascioli; Sato, João Ricardo; Muthukumaraswamy, Suresh D.; Yonamine, Maurício; Waguespack, Marian; Lomnicka, Izabela; Barker, Steven A.; da Silveira, Dartiu Xavier

    2015-01-01

    Ritual use of ayahuasca, an amazonian Amerindian medicine turned sacrament in syncretic religions in Brazil, is rapidly growing around the world. Because of this internationalization, a comprehensive understanding of the pharmacological mechanisms of action of the brew and the neural correlates of the modified states of consciousness it induces is important. Employing a combination of electroencephalogram (EEG) recordings and quantification of ayahuasca's compounds and their metabolites in the systemic circulation we found ayahuasca to induce a biphasic effect in the brain. This effect was composed of reduced power in the alpha band (8–13 Hz) after 50 minutes from ingestion of the brew and increased slow- and fast-gamma power (30–50 and 50–100 Hz, respectively) between 75 and 125 minutes. Alpha power reductions were mostly located at left parieto-occipital cortex, slow-gamma power increase was observed at left centro-parieto-occipital, left fronto-temporal and right frontal cortices while fast-gamma increases were significant at left centro-parieto-occipital, left fronto-temporal, right frontal and right parieto-occipital cortices. These effects were significantly associated with circulating levels of ayahuasca’s chemical compounds, mostly N,N-dimethyltryptamine (DMT), harmine, harmaline and tetrahydroharmine and some of their metabolites. An interpretation based on a cognitive and emotional framework relevant to the ritual use of ayahuasca, as well as it's potential therapeutic effects is offered. PMID:26421727

  13. Acute Biphasic Effects of Ayahuasca.

    Science.gov (United States)

    Schenberg, Eduardo Ekman; Alexandre, João Felipe Morel; Filev, Renato; Cravo, Andre Mascioli; Sato, João Ricardo; Muthukumaraswamy, Suresh D; Yonamine, Maurício; Waguespack, Marian; Lomnicka, Izabela; Barker, Steven A; da Silveira, Dartiu Xavier

    2015-01-01

    Ritual use of ayahuasca, an amazonian Amerindian medicine turned sacrament in syncretic religions in Brazil, is rapidly growing around the world. Because of this internationalization, a comprehensive understanding of the pharmacological mechanisms of action of the brew and the neural correlates of the modified states of consciousness it induces is important. Employing a combination of electroencephalogram (EEG) recordings and quantification of ayahuasca's compounds and their metabolites in the systemic circulation we found ayahuasca to induce a biphasic effect in the brain. This effect was composed of reduced power in the alpha band (8-13 Hz) after 50 minutes from ingestion of the brew and increased slow- and fast-gamma power (30-50 and 50-100 Hz, respectively) between 75 and 125 minutes. Alpha power reductions were mostly located at left parieto-occipital cortex, slow-gamma power increase was observed at left centro-parieto-occipital, left fronto-temporal and right frontal cortices while fast-gamma increases were significant at left centro-parieto-occipital, left fronto-temporal, right frontal and right parieto-occipital cortices. These effects were significantly associated with circulating levels of ayahuasca's chemical compounds, mostly N,N-dimethyltryptamine (DMT), harmine, harmaline and tetrahydroharmine and some of their metabolites. An interpretation based on a cognitive and emotional framework relevant to the ritual use of ayahuasca, as well as it's potential therapeutic effects is offered.

  14. Effects of low-dose recombinant human insulin-like growth factor-I on insulin sensitivity, growth hormone and glucagon levels in young adults with insulin-dependent diabetes mellitus.

    Science.gov (United States)

    Acerini, C L; Harris, D A; Matyka, K A; Watts, A P; Umpleby, A M; Russell-Jones, D L; Dunger, D B

    1998-12-01

    Despite recent interest in the therapeutic potential of recombinant human insulin-like growth factor-I (rhIGF-I) in the treatment of diabetes mellitus, its mechanism of action is still not defined. We have studied the effects of low-dose bolus subcutaneous rhIGF-I (40 microg/kg and 20 microg/kg) on insulin sensitivity, growth hormone (GH) and glucagon levels in seven young adults with insulin-dependent diabetes mellitus (IDDM) using a randomized double-blind placebo-controlled crossover study design. Each was subjected to a euglycemic clamp (5 mmol/L) protocol consisting of a variable-rate insulin infusion clamp (6:00 PM to 8:00 AM) followed by a two-dose hyperinsulinemic clamp (insulin infusion of 0.75 mU x kg(-1) x min(-1) from 8 to 10 AM and 1.5 mU x kg(-1) x min(-1) from 10 AM to 12 noon) incorporating [6,6 2H2]glucose tracer for determination of glucose production/utilization rates. Following rhIGF-I administration, the serum IGF-I level (mean +/- SEM) increased (40 microg/kg, 655 +/- 90 ng/mL, P overnight GH level (40 microg/kg, 9.1 +/- 1.4 mU/L, P = .04; 20 microg/kg, 9.6 +/- 2.0 mU/L, P = .12; placebo, 11.3 +/- 1.7 mU/L) and GH pulse amplitude (40 microg/kg, 18.8 +/- 2.9 mU/L, P = .04; 20 microg/kg, 17.0 +/- 3.4 mU/L, P > .05; placebo, 23.0 +/- 3.7 mU/L) were also reduced. No differences in glucagon, IGF binding protein-1 (IGFBP-1), acetoacetate, or beta-hydroxybutyrate levels were found. During the hyperinsulinemic clamp conditions, no differences in glucose utilization were noted, whereas hepatic glucose production was reduced by rhIGF-I 40 microg/kg (P = .05). Our data demonstrate that in subjects with IDDM, low-dose subcutaneous rhIGF-I leads to a dose-dependent reduction in the insulin level for euglycemia overnight that parallels the decrease in overnight GH levels, but glucagon and IGFBP-1 levels remain unchanged. The decreases in hepatic glucose production during the hyperinsulinemic clamp study observed the following day are likely related to GH

  15. Lipodystrophy in human immunodeficiency virus patients impairs insulin action and induces defects in beta-cell function

    DEFF Research Database (Denmark)

    Andersen, Ove; Haugaard, Steen B; Andersen, Ulrik B

    2003-01-01

    The pathophysiology of insulin resistance in human immunodeficiency virus (HIV)-associated lipodystrophy syndrome (HALS) is not fully clarified. We investigated 18 men with HALS and 18 HIV-positive males without lipodystrophy (control subjects). Duration and modality of antiretroviral therapy wer...... =.006), whereas levels of basal and insulin-stimulated oxidative glucose metabolism (OGM) (2.4 v 2.3, P =.55, and 3.3 v 4.0, P =.064, respectively) were not significantly different between groups. Despite comparable total fat masses, dual energy x-ray absorptiometry (DEXA) scans showed...

  16. Engineering of a Novel Simplified Human Insulin-Like Peptide 5 Agonist.

    Science.gov (United States)

    Patil, Nitin A; Hughes, Richard A; Rosengren, K Johan; Kocan, Martina; Ang, Sheng Yu; Tailhades, Julien; Separovic, Frances; Summers, Roger J; Grosse, Johannes; Wade, John D; Bathgate, Ross A D; Hossain, Mohammed Akhter

    2016-03-10

    Insulin-like peptide 5 (INSL5) has recently been discovered as only the second orexigenic gut hormone after ghrelin. As we have previously reported, INSL5 is extremely difficult to assemble and oxidize into its two-chain three-disulfide structure. The focus of this study was to generate structure-activity relationships (SARs) of INSL5 and use it to develop a potent and simpler INSL5 mimetic with RXFP4 agonist activity. A series of human and mouse INSL5 (hINSL5/mINSL5) analogues were designed and chemically synthesized, resulting in a chimeric INSL5 analogue exhibiting more than 10-fold higher potency (0.35 nM) at human RXFP4 compared with native hINSL5 (4.57 nM). The SAR study also identified a key residue (K(A15)) in the A-chain of mINSL5 that contributes to improved RXFP4 affinity and potency of mINSL5 compared with hINSL5. This knowledge ultimately led us to engineer a minimized hINSL5 mimetic agonist that retains native hINSL5-like RXFP4 affinity and potency at human RXFP4. This minimized analogue was synthesized in 17.5-fold higher yield and in less time compared with hINSL5.

  17. Protein kinase C is differentially regulated by thrombin, insulin, and epidermal growth factor in human mammary tumor cells

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, M.L.; Tellez-Inon, M.T. (Instituto de Ingenieria Genetica y Biologia Molecular, Buenos Aires (Argentina)); Medrano, E.E.; Cafferatta, E.G.A. (Instituto de Investigaciones Bioquimicas Fundacion Campomar, Buenos Aires (Argentina))

    1988-03-01

    The exposure of serum-deprived mammary tumor cells MCF-7 and T-47D to insulin, thrombin, and epidermal growth factor (EGF) resulted in dramatic modifications in the activity and in the translocation capacity of protein kinase C from cytosol to membrane fractions. Insulin induces a 600% activation of the enzyme after 5 h of exposure to the hormone in MCF-7 cells; thrombin either activates (200% in MCF-7) or down-regulates (in T-47D), and EGF exerts only a moderate effect. Thus, the growth factors studied modulate differentially the protein kinase C activity in human mammary tumor cells. The physiological significance of the results obtained are discussed in terms of the growth response elicited by insulin, thrombin, and EGF.

  18. Human iPS cell-derived insulin producing cells form vascularized organoids under the kidney capsules of diabetic mice.

    Directory of Open Access Journals (Sweden)

    Sudhanshu P Raikwar

    Full Text Available Type 1 diabetes (T1D is caused by autoimmune disease that leads to the destruction of pancreatic β-cells. Transplantation of cadaveric pancreatic organs or pancreatic islets can restore normal physiology. However, there is a chronic shortage of cadaveric organs, limiting the treatment of the majority of patients on the pancreas transplantation waiting list. Here, we hypothesized that human iPS cells can be directly differentiated into insulin producing cells (IPCs capable of secreting insulin. Using a series of pancreatic growth factors, we successfully generated iPS cells derived IPCs. Furthermore, to investigate the capability of these cells to secrete insulin in vivo, the differentiated cells were transplanted under the kidney capsules of diabetic immunodeficient mice. Serum glucose levels gradually declined to either normal or near normal levels over 150 days, suggesting that the IPCs were secreting insulin. In addition, using MRI, a 3D organoid appeared as a white patch on the transplanted kidneys but not on the control kidneys. These organoids showed neo-vascularization and stained positive for insulin and glucagon. All together, these data show that a pancreatic organ can be created in vivo providing evidence that iPS cells might be a novel option for the treatment of T1D.

  19. Synergistic bombesin and insulin stimulation of DNA synthesis in human fetal kidney in serum-free culture.

    Science.gov (United States)

    Brière, N; Chailler, P

    1993-05-01

    The respective influences of growth factors during kidney development can be directly evaluated using the chemically-defined serum-free culture system perfected in our laboratory. Since, in this culture model, conditions are minimal for growth and differentiation, DNA synthesis sharply decreases during the first 48 h. The addition of epidermal growth factor (EGF, 100 ng/ml), insulin (5 micrograms/ml) and transferrin (5 micrograms/ml) significantly restores this important cellular function. The objective of the present study was to determine the influence of bombesin, a potent mitogen, supplemented alone or in combination with insulin, transferrin and/or EGF. Cortical explants of human fetal kidneys (17-20 weeks) were maintained during 5 days in culture. When compared with 5 day controls (L-15 medium only), bombesin generated a maximal though weak effect on DNA synthesis at a concentration of 0.3 nM, corresponding to a stimulation index (SI) of 22%. When combined with either transferrin or EGF, or with transferrin plus EGF, bombesin did not alter the SI of individual factors. Insulin, in turn, greatly increased DNA synthesis (SI = 169%), while bombesin strongly potentiated this effect (SI = 275%). Transferrin also enhanced insulin SI from 169 to 240%. When added as a third factor, bombesin further potentiated the effectiveness (SI = 338%) of the combination insulin plus transferrin. These results indicate that bombesin controls cell proliferation in synergism with other regulators and hence may act as a competence growth factor during nephrogenesis.

  20. Differentiation of Human Mesenchymal Stem Cells into Insulin Producing Cells by Using A Lentiviral Vector Carrying PDX1

    Directory of Open Access Journals (Sweden)

    Amir Allahverdi

    2015-07-01

    Full Text Available Objective: Type I diabetes is an immunologically-mediated devastation of insulin producing cells (IPCs in the pancreatic islet. Stem cells that produce β-cells are a new promising tool. Adult stem cells such as mesenchymal stem cells (MSCs are self renewing multi potent cells showing capabilities to differentiate into ectodermal, mesodermal and endodermal tissues. Pancreatic and duodenal homeobox factor 1 (PDX1 is a master regulator gene required for embryonic development of the pancreas and is crucial for normal pancreatic islets activities in adults. Materials and Methods: We induced the over-expression of the PDX1 gene in human bone marrow MSCs (BM-MSCs by Lenti-PDX1 in order to generate IPCs. Next, we examine the ability of the cells by measuring insulin/c-peptide production and INSULIN and PDX1 gene expressions. Results: After transduction, MSCs changed their morphology at day 5 and gradually differentiated into IPCs. INSULIN and PDX1 expressions were confirmed by real time polymerase chain reaction (RT-PCR and immunostaining. IPC secreted insulin and C-peptide in the media that contained different glucose concentrations. Conclusion: MSCs differentiated into IPCs by genetic manipulation. Our result showed that lentiviral vectors could deliver PDX1 gene to MSCs and induce pancreatic differentiation.

  1. Activation of IGF-1 and insulin signaling pathways ameliorate mitochondrial function and energy metabolism in Huntington's Disease human lymphoblasts.

    Science.gov (United States)

    Naia, Luana; Ferreira, I Luísa; Cunha-Oliveira, Teresa; Duarte, Ana I; Ribeiro, Márcio; Rosenstock, Tatiana R; Laço, Mário N; Ribeiro, Maria J; Oliveira, Catarina R; Saudou, Frédéric; Humbert, Sandrine; Rego, A Cristina

    2015-02-01

    Huntington's disease (HD) is an inherited neurodegenerative disease caused by a polyglutamine repeat expansion in the huntingtin protein. Mitochondrial dysfunction associated with energy failure plays an important role in this untreated pathology. In the present work, we used lymphoblasts obtained from HD patients or unaffected parentally related individuals to study the protective role of insulin-like growth factor 1 (IGF-1) versus insulin (at low nM) on signaling and metabolic and mitochondrial functions. Deregulation of intracellular signaling pathways linked to activation of insulin and IGF-1 receptors (IR,IGF-1R), Akt, and ERK was largely restored by IGF-1 and, at a less extent, by insulin in HD human lymphoblasts. Importantly, both neurotrophic factors stimulated huntingtin phosphorylation at Ser421 in HD cells. IGF-1 and insulin also rescued energy levels in HD peripheral cells, as evaluated by increased ATP and phosphocreatine, and decreased lactate levels. Moreover, IGF-1 effectively ameliorated O2 consumption and mitochondrial membrane potential (Δψm) in HD lymphoblasts, which occurred concomitantly with increased levels of cytochrome c. Indeed, constitutive phosphorylation of huntingtin was able to restore the Δψm in lymphoblasts expressing an abnormal expansion of polyglutamines. HD lymphoblasts further exhibited increased intracellular Ca(2+) levels before and after exposure to hydrogen peroxide (H2O2), and decreased mitochondrial Ca(2+) accumulation, being the later recovered by IGF-1 and insulin in HD lymphoblasts pre-exposed to H2O2. In summary, the data support an important role for IR/IGF-1R mediated activation of signaling pathways and improved mitochondrial and metabolic function in HD human lymphoblasts.

  2. Evaluation of non-isothermal methods in stability studies of human insulin pharmaceutical preparations.

    Science.gov (United States)

    Oliva, Alexis; Suárez, Marta; Hernández, Juan Ramón; Llabrés, Matías; Fariña, José B

    2009-05-01

    The purpose of this research was to study the thermal stability of a human insulin pharmaceutical preparation using non-isothermal conditions and comparison with classical isothermal experiments. The isothermal studies were performed in the temperature range 20-60 degrees C, whereas non-isothermal stability studies were performed using a linear increasing temperature program, heating rate 0.25 degrees C per hour and temperature interval 30-70 degrees C. Under isothermal conditions, an apparent first-order degradation process was observed at all temperatures. The linear Arrhenius plot suggested that the insulin degradation mechanism was the same within the studied temperature range, with quite large uncertainties due to the small number of degrees of freedom based only on the scatter in the plot, giving an estimated shelf-life at 25 degrees C of 199.1 days. In non-isothermal conditions, the integral approach was used to estimate the activation parameters. It provides results in good agreement with those of the traditional method, but with the advantage that the uncertainty in the final result directly reflects the goodness of fit of the experimental data, since it takes into account the scatter in the original data. The estimated shelf-life in non-isothermal conditions was quite close to the value derived from isothermal data, 191.4 days, although the 95% confidence interval estimated were slightly higher. This is due to the differences in the estimation method and the nature of the experimental errors. The bootstrap technique is also applied to estimating confidence limits for the Arrhenius parameters and shelf-life. This method is very useful when the underlying distribution function of the parameters is unknown. The results obtained indicate that the Arrhenius parameters follow a normal distribution, whereas the shelf-life follows a log-normal distribution. In any case, the results obtained show that there is no difference between the asymptotic and bootstrap

  3. Size-dependent cytotoxicity of Fe3O4 nanoparticles induced by biphasic regulation of oxidative stress in different human hepatoma cells.

    Science.gov (United States)

    Xie, Yuexia; Liu, Dejun; Cai, Chenlei; Chen, Xiaojing; Zhou, Yan; Wu, Liangliang; Sun, Yongwei; Dai, Huili; Kong, Xianming; Liu, Peifeng

    2016-01-01

    The application of Fe3O4 nanoparticles (NPs) has made great progress in the diagnosis of disease and in the drug delivery system for cancer therapy, but the relative mechanisms of potential toxicity induced by Fe3O4 have not kept pace with its development in the application, which has hampered its further clinical application. In this article, we used two kinds of human hepatoma cell lines, SK-Hep-1 and Hep3B, to investigate the cytotoxic effects and the involved mechanisms of small Fe3O4 NPs with different diameters (6 nm, 9 nm, and 14 nm). Results showed that the size of NPs effectively influences the cytotoxicity of hepatoma cells: 6 nm Fe3O4 NPs exhibited negligible cytotoxicity and 9 nm Fe3O4 NPs affected cytotoxicity via cellular mitochondrial dysfunction and by inducing necrosis mediated through the mitochondria-dependent intracellular reactive oxygen species generation. Meanwhile, 14 nm Fe3O4 NPs induced cytotoxicity by impairing the integrity of plasma membrane and promoting massive lactate dehydrogenase leakage. These results explain the detailed mechanism of different diameters of small Fe3O4 NPs-induced cytotoxicity. We anticipate that this study will provide different insights into the cytotoxicity mechanism of Fe3O4 NPs, so as to make them safer to use in clinical application.

  4. Bi-phasic effect of interferon (IFN)-alpha: IFN-alpha up- and down-regulates interleukin-4 signaling in human T cells

    DEFF Research Database (Denmark)

    Eriksen, Karsten Wessel; Sommer, Viveca Horst; Woetmann, Anders

    2003-01-01

    Interferon (IFN)-alpha/beta is produced by virally infected cells and is believed to play an important role in early phases of the innate immune response. In addition, IFN-alpha/beta inhibits interleukin (IL)-4 signaling in B cells and monocytes, suggesting that IFN-alpha/beta (like IFN-gamma) is......Interferon (IFN)-alpha/beta is produced by virally infected cells and is believed to play an important role in early phases of the innate immune response. In addition, IFN-alpha/beta inhibits interleukin (IL)-4 signaling in B cells and monocytes, suggesting that IFN-alpha/beta (like IFN......-gamma) is a Th1 cytokine. Here, we study cross-talk between IFN-alpha and IL-4 in human T cells. As expected, stimulation with IFN-alpha for 12-24 h inhibits IL-4 signaling. Surprisingly, however, IFN-alpha has the opposite effect on IL-4 signaling at earlier time points (up to 6 h). Thus, IFN-alpha enhances IL...

  5. Biphasic influence of PGE2 on the resorption activity of osteoclast-like cells derived from human peripheral blood monocytes and mouse RAW264.7 cells.

    Science.gov (United States)

    Lutter, Anne-Helen; Hempel, Ute; Anderer, Ursula; Dieter, Peter

    2016-08-01

    Osteoclasts are large bone-resorbing cells of hematopoietic origin. Their main function is to dissolve the inorganic component hydroxyapatite and to degrade the organic bone matrix. Prostaglandin E2 (PGE2) indirectly affects osteoclasts by stimulating osteoblasts to release factors that influence osteoclast activity. The direct effect of PGE2 on osteoclasts is still controversial. To study the influence of PGE2 on osteoclast activity, human peripheral blood monocytes (hPBMC) and mouse RAW264.7 cells were cultured on osteoblast-derived extracellular matrix. hPBMC and RAW264.7 cells were differentiated by the addition of macrophage colony-stimulation factor and receptor activator of NFκB ligand and treated with PGE2 before and after differentiation induction. The pit area, an indicator of resorption activity, and the activity of tartrate-resistant acid phosphatase were dose-dependently inhibited when PGE2 was present ab initio, whereas the resorption activity remained unchanged when the cells were exposed to PGE2 from day 4 of culture. These results lead to the conclusion that PGE2 treatment inhibits only the differentiation of precursor osteoclasts whereas differentiated osteoclasts are not affected.

  6. A histomorphometric and micro-computed tomography study of bone regeneration in the maxillary sinus comparing biphasic calcium phosphate and deproteinized cancellous bovine bone in a human split-mouth model

    NARCIS (Netherlands)

    de Lange, G.L.; Overman, J.R.; Farre-Guasch, E.; Korstjens, C.M.; Hartman, B.; Langenbach, G.E.J.; van Duin, M.A.; Klein-Nulend, J.

    2014-01-01

    Objective The gain of mineralized bone was compared between deproteinized bovine bone allograft (DBA) and biphasic calcium phosphate (BCP) for dental implant placement. Study Design Five patients with atrophic maxillae underwent bilateral sinus elevation with DBA (Bio-Oss) and BCP (Straumann BoneCer

  7. How does insulin resistance arise, and how does it cause disease?: Human genetic lessons

    OpenAIRE

    Semple, Robert Kenneth

    2016-01-01

    This is the author accepted manuscript. The final version is available from BioScientifica via http://dx.doi.org/10.1530/EJE-15-1131 Insulin orchestrates physiological responses to ingested nutrients, however although it elicits widely ramifying metabolic and trophic responses from diverse tissues, "insulin resistance", a pandemic metabolic derangement commonly associated with obesity, is usually defined solely by blunting of insulin's hypoglycaemic effect. Recent study of monogenic forms ...

  8. Insulin Resistance

    DEFF Research Database (Denmark)

    Jensen, Benjamin Anderschou Holbech

    Insulin resistance (IR) is escalating with alarming pace and is no longer restricted to westernized countries. As a forerunner for some of the most serious threats to human health including metabolic syndrome, cardiovascular diseases, and type 2-diabetes, the need for new treatment modalities...... interventions. We further show that improving the inflammatory toning, using fish oil as fat source, protects mice against diet induced obesity and -inflammation while preserving insulin sensitivity, even in the absence of free fatty acid receptor 4. Conversely, HFD-induced intestinal dysbiosis is associated...

  9. Immature transformed rat islet beta-cells differentially express C-peptides derived from the genes coding for insulin I and II as well as a transfected human insulin gene

    DEFF Research Database (Denmark)

    Blume, N; Petersen, J S; Andersen, L C;

    1992-01-01

    Synthetic peptides representing unique sequences in rat proinsulin C-peptide I and II were used to generate highly specific antisera, which, when applied on sections of normal rat pancreas, confirm a homogeneous coexpression of the two C-peptides in all islet beta-cells. Insulin gene expression...... is induced in the transformed heterogeneous rat islet cell clone, NHI-6F, by transient in vivo passage. During this process a transfected human insulin gene is coactivated with the endogenous nonallelic rat insulin I and II genes. Newly established cultures from NHI-6F insulinomas having a high frequency...

  10. Size-dependent cytotoxicity of Fe3O4 nanoparticles induced by biphasic regulation of oxidative stress in different human hepatoma cells

    Directory of Open Access Journals (Sweden)

    Xie Y

    2016-07-01

    Full Text Available Yuexia Xie,1,2,* Dejun Liu,3,* Chenlei Cai,1,* Xiaojing Chen,1 Yan Zhou,1 Liangliang Wu,1 Yongwei Sun,3 Huili Dai,1,2 Xianming Kong,1,2 Peifeng Liu1,2 1Central Laboratory, 2State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, 3Department of Biliary-Pancreatic Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: The application of Fe3O4 nanoparticles (NPs has made great progress in the diagnosis of disease and in the drug delivery system for cancer therapy, but the relative mecha­nisms of potential toxicity induced by Fe3O4 have not kept pace with its development in the application, which has hampered its further clinical application. In this article, we used two kinds of human hepatoma cell lines, SK-Hep-1 and Hep3B, to investigate the cytotoxic effects and the involved mechanisms of small Fe3O4 NPs with different diameters (6 nm, 9 nm, and 14 nm. Results showed that the size of NPs effectively influences the cytotoxicity of hepatoma cells: 6 nm Fe3O4 NPs exhibited negligible cytotoxicity and 9 nm Fe3O4 NPs affected cytotoxicity via cellular mitochondrial dysfunction and by inducing necrosis mediated through the mitochondria-dependent intracellular reactive oxygen species generation. Meanwhile, 14 nm Fe3O4 NPs induced cytotoxicity by impairing the integrity of plasma membrane and promoting massive lactate dehydrogenase leakage. These results explain the detailed mechanism of different diameters of small Fe3O4 NPs-induced cytotoxicity. We anticipate that this study will provide different insights into the cytotoxicity mechanism of Fe3O4 NPs, so as to make them safer to use in clinical application. Keywords: hepatoma cells, nanoparticles, cytotoxicity, mechanism, oxidative stress

  11. Insulin sensitivity is independent of lipid binding protein trafficking at the plasma membrane in human skeletal muscle

    DEFF Research Database (Denmark)

    Jordy, Andreas Børsting; Serup, Annette Karen; Karstoft, Kristian

    2014-01-01

    The aim of the present study was to investigate lipid-induced regulation of lipid binding proteins in human skeletal muscle and the impact hereof on insulin sensitivity. Eleven healthy male subjects underwent a 3-day hyper-caloric and high-fat diet regime. Muscle biopsies were taken before......-regulated by increased fatty acid availability. This suggests a time dependency in the up-regulation of FAT/CD36 and FABPpm protein during high availability of plasma fatty acids. Furthermore, we did not detect FATP1 and FATP4 protein in giant sarcolemmal vesicles obtained from human skeletal muscle. In conclusion......, this study shows that a short-term lipid-load increases mRNA content of key lipid handling proteins in human muscle. However, decreased insulin sensitivity after high-fat diet is not accompanied with relocation of FAT/CD36 or FABPpm protein to the sarcolemma. Finally, FATP1 and FATP4 protein could...

  12. Regeneration of insulin-producing pancreatic cells using a volatile bioactive compound and human teeth.

    Science.gov (United States)

    Okada, Mio; Imai, Toshio; Yaegaki, Ken; Ishkitiev, Nikolay; Tanaka, Tomoko

    2014-10-30

    Transplantation of insulin (INS)-secreting cells differentiated in vitro from stem cells promises a safer and easier treatment of severe diabetes mellitus. A volatile bioactive compound, hydrogen sulfide (H2S), promotes cell differentiation; human tooth-pulp stem cells undergo hepatic differentiation. The aim of this study is to develop a novel protocol using H2S to enhance pancreatic differentiation from the CD117(+) cell fraction of human tooth pulp. During the differentiation, the cells were exposed to 0.1 ng ml(-1) H2S. Immunocytochemistry, RT-PCR, determination of INS c-peptide content and flow cytometry of pancreatically related markers were carried out. Expression of WNT and the PI3K/AKT signaling pathway were also determined by PCR array. After differentiation, INS, glucagon (GCG), somatostatin (SST) and pancreatic polypeptide (PPY) were positive when examined by immunofluorescence. INS and GCG were also determined flow-cytometrically. Only the cells expressing INS increased after H2S exposure. The number of cells expressing GCG was significantly decreased. Genes involved in canonical WNT and the WNT/calcium pathways were highly expressed after H2S exposure. H2S accelerated INS synthesis and secretion by regenerated INS-producing cells from human teeth. All signaling pathway functions of the PI3K-AKT pathway were extremely activated by H2S exposure. The matured INS-producing cells originating in human teeth were increased by H2S in order to control blood-glucose level.

  13. Computer-aided process analysis and economic evaluation for biosynthetic human insulin production-A case study.

    Science.gov (United States)

    Petrides, D; Sapidou, E; Calandranis, J

    1995-12-05

    Human insulin was the first mammalian protein produced in bacteria using recombinant DNA technology. Two technologies were developed; the first based on the separate expression of precursors of chains A and B of insulin, and the second based on the expression of a precursor of proinsulin as a Trp-E fusion protein. Both technologies utilized Escherichia coli as an expression system. Later, a third technology was developed based on a strain of yeast that can secrete a precursor of insulin. The second E. coli process, a variation of which has been commercialized by Eli Lilly and Co., is analyzed in this article from a process design and economic evaluation viewpoint. The objective of this work is to elucidate the technical complexity and high cost associated with the manufacturing of biopharmaceuticals. Human insulin is a good example of a protein-based biopharmaceutical produced in large quantities (a fex tons per year) that requires large scale equipment and presents a multitude of scale-up challenges. Based onthe analysis, a number of conclusions are drawn regarding the cost breakdown and cost dependency on process parameters. Recommendations are made for cost reduction and environmental impact minimization. This analysis was performed using a software tool for computer-aided bioprocess design. (c) 1995 John Wiley & Sons, Inc.

  14. Rac1 signaling is required for insulin-stimulated glucose uptake and is dysregulated in insulin-resistant murine and human skeletal muscle

    DEFF Research Database (Denmark)

    Sylow, Lykke; Jensen, Thomas Elbenhardt; Kleinert, Maximilian

    2013-01-01

    The actin-cytoskeleton-regulating GTPase Rac1 is required for insulin-stimulated GLUT4 translocation in cultured muscle cells. However, involvement of Rac1 and its downstream signaling in glucose transport in insulin sensitive and insulin resistant mature skeletal muscle has not previously been...

  15. Beta-cell dysfunction and low insulin clearance in insulin-resistant human immunodeficiency virus (HIV)-infected patients with lipodystrophy

    DEFF Research Database (Denmark)

    Haugaard, Steen B; Andersen, Ove; Vølund, Aage;

    2005-01-01

    of diabetes mellitus or impaired glucose tolerance. Prehepatic insulin secretion rates were estimated by deconvolution of C-peptide concentrations. A composite measure of insulin sensitivity was derived from the OGTT. RESULTS: Beta-cell secretory capacity (i.e. the rate of change in insulin secretion per unit...

  16. Lipodystrophy in human immunodeficiency virus patients impairs insulin action and induces defects in beta-cell function.

    Science.gov (United States)

    Andersen, Ove; Haugaard, Steen B; Andersen, Ulrik B; Friis-Møller, Nina; Storgaard, Heidi; Vølund, Aage; Nielsen, Jens Ole; Iversen, Johan; Madsbad, Sten

    2003-10-01

    The pathophysiology of insulin resistance in human immunodeficiency virus (HIV)-associated lipodystrophy syndrome (HALS) is not fully clarified. We investigated 18 men with HALS and 18 HIV-positive males without lipodystrophy (control subjects). Duration and modality of antiretroviral therapy were similar between study groups. A hyperinsulinemic euglycemic clamp showed an impaired glucose disposal rate (GDR) in HALS patients (5.6 v 8.3 mg glucose/min. kg(FFM), P =.0006). As demonstrated by indirect calorimetry, HALS patients showed an impaired nonoxidative glucose metabolism (NOGM, 2.2 v 4.2, P =.006), whereas levels of basal and insulin-stimulated oxidative glucose metabolism (OGM) (2.4 v 2.3, P =.55, and 3.3 v 4.0, P =.064, respectively) were not significantly different between groups. Despite comparable total fat masses, dual energy x-ray absorptiometry (DEXA) scans showed that the percentage of limb fat (ie, peripheral-fat-mass/[peripheral-fat-mass + trunk-fat-mass]. 100%) was reduced in HALS patients (36% v 46%, P =.0002). Multiple linear regression analysis indicated that percentage of limb fat explained 53% of the variability of GDR and 45% of the variability of NOGM in HALS patients. In HALS patients, leg fat mass correlated positively with NOGM (r =.51, P <.05), whereas abdominal fat mass and NOGM did not correlate (P =.91). Analyzing the relationship between first phase insulin secretion and insulin sensitivity, 6 HALS patients compared with none of the control subjects exhibited impaired insulin secretion (P <.05). Our data suggest that fat redistribution independently of antiretroviral therapy is highly related to insulin resistance in HALS patients. Furthermore, in HALS patients, impaired glucose metabolism most likely relates to decreased NOGM and to defects in beta-cell function.

  17. Human insulin-like growth factor II leader 2 mediates internal initiation of translation

    DEFF Research Database (Denmark)

    Pedersen, Susanne K; Christiansen, Jan; Hansen, Thomas v O

    2002-01-01

    Insulin-like growth factor II (IGF-II) is a fetal growth factor, which belongs to the family of insulin-like peptides. During fetal life, the IGF-II gene generates three mRNAs with different 5' untranslated regions (UTRs), but identical coding regions and 3' UTRs. We have shown previously that IG...

  18. Growth hormone-induced insulin resistance in human subjects involves reduced pyruvate dehydrogenase activity

    DEFF Research Database (Denmark)

    Nellemann, Birgitte; Vendelbo, Mikkel H; Nielsen, Thomas S

    2014-01-01

    Insulin resistance induced by growth hormone (GH) is linked to promotion of lipolysis by unknown mechanisms. We hypothesized that suppression of the activity of pyruvate dehydrogenase in the active form (PDHa) underlies GH-induced insulin resistance similar to what is observed during fasting....

  19. Prolonged Fasting Identifies Skeletal Muscle Mitochondrial Dysfunction as Consequence Rather Than Cause of Human Insulin Resistance

    NARCIS (Netherlands)

    Hoeks, J.; Herpen, N.A.; Mensink, M.R.; Moonen-Kornips, E.; Beurden, van D.; Hesselink, M.K.C.; Schrauwen, P.

    2010-01-01

    OBJECTIVE-Type 2 diabetes and insulin resistance have been associated with mitochondrial dysfunction, but it is debated whether this is a primary factor in the pathogenesis of the disease. To test the concept that mitochondrial dysfunction is secondary to the development of insulin resistance, we em

  20. Incretin hormone and insulin responses to oral versus intravenous lipid administration in humans

    DEFF Research Database (Denmark)

    Lindgren, Ola; Carr, Richard D; Deacon, Carolyn F;

    2011-01-01

    Context: The incretin effect is responsible for the higher insulin response to oral glucose than to iv glucose at matching glucose levels. It is notknownwhetherthis effect is restricted to glucose only. Objective: The aim of the study was to examine whether insulin and incretin hormone responses ...

  1. Protamine coated proliposomes of recombinant human insulin encased in Eudragit S100 coated capsule offered improved peptide delivery and permeation across Caco-2 cells.

    Science.gov (United States)

    Sharma, Shiva; Jyoti, Kiran; Sinha, Richa; Katyal, Anju; Jain, Upendra Kumar; Madan, Jitender

    2016-10-01

    In present investigation, recombinant human insulin loaded proliposomes and protamine sulphate coated proliposomes (rh insulin-proliposomes and Pt-rh insulin proliposomes) were encased in Eudragit S100 coated capsule to offer peptide release in simulated intestinal conditions. The particle size and zeta potential of Pt-rh insulin proliposomes were measured to be 583.2±10.2nm/+28.3±3.7mV significantly (P<0.05) higher than 569.7±14.9nm/-37.9±4.3mV and 534.6±24.6nm/-42.7±2.8mV of rh insulin proliposomes and proliposomes, respectively. Next, shape and surface morphology analysis pointed out the successful transformation of proliposomes in to spherical shaped liposomes. Furthermore, in vitro release study specified that free rh insulin solution encapsulated in uncoated gelatine capsule released 97.8% of peptide within 1h in SGF (pH~1.2). On other hand, rh insulin-proliposomes and Pt-rh insulin proliposomes encased in Eudragit S100 coated capsule released 93.2% and 81.6% of peptide, up to 24 h in SIF (pH~7.2). SDS-PAGE and circular dichroism (CD) ascertained the stability and intactness of isolated rh insulin from tailored dosage forms. In last, cellular uptake in Caco-2 cells indicating the superiority of Pt-rh insulin proliposomes in comparison to rh-insulin proliposomes and free rh insulin solution, respectively. In conclusion, Pt-rh insulin proliposomes displayed promising results and may be considered for further investigations.

  2. Glucose turnover and hormonal changes during insulin-induced hypoglycemia in trained humans

    DEFF Research Database (Denmark)

    Kjær, Michael; Mikines, K J; Christensen, N J;

    1984-01-01

    Eight athletes (T), studied the third morning after the last exercise session, and seven sedentary males (C) (maximal O2 consumption 65 +/- 4 vs. 49 +/- 4 (SE) ml X kg-1 X min-1, for T and C men, respectively) had insulin infused until plasma glucose, at an insulin level of 1,600 pmol X l-1, was ...... of heart rate, free fatty acid, and glycerol was faster. Responses of norepinephrine, cortisol, C-peptide, and lactate were similar in the two groups. Training radically changes hormonal responses but not glucose kinetics in insulin hypoglycemia.......Eight athletes (T), studied the third morning after the last exercise session, and seven sedentary males (C) (maximal O2 consumption 65 +/- 4 vs. 49 +/- 4 (SE) ml X kg-1 X min-1, for T and C men, respectively) had insulin infused until plasma glucose, at an insulin level of 1,600 pmol X l-1, was 1...

  3. Insulin Secretagogues

    Science.gov (United States)

    ... Your Body in Balance › Insulin Secretagogues Fact Sheet Insulin Secretagogues March, 2012 Download PDFs English Espanol Editors ... medicines can help you stay healthy. What are insulin secretagogues? Insulin secretagogues (pronounced seh-KREET-ah-gogs) ...

  4. Surface-expressed insulin receptors as well as IGF-I receptors both contribute to the mitogenic effects of human insulin and its analogues

    DEFF Research Database (Denmark)

    Lundby, Anders; Bolvig, Pernille; Hegelund, Anne Charlotte;

    2015-01-01

    therefore optimized mitogenicity assay conditions for a panel of five cell lines. All cell lines expressed insulin receptors (IR), IGF-I receptors (IGF-IR) and hybrid receptors, and in all cell lines, insulin as well as the comparator compounds X10 and IGF-I caused phosphorylation of the IR as well as IGF......There is a medical need for new insulin analogues. Yet, molecular alterations to the insulin molecule can theoretically result in analogues with carcinogenic effects. Preclinical carcinogenicity risk assessment for insulin analogues rests to a large extent on mitogenicity assays in cell lines. We......-IR. Insulin exhibited mitogenicity EC50 values in the single-digit nanomolar to picomolar range. We observed correlations across cell types between (i) mitogenic potency of insulin and IGF-IR/IR ratio, (ii) Akt phosphorylation and mitogenic potency and (iii) Akt phosphorylation and IR phosphorylation. Using...

  5. Insulin and Insulin Resistance

    OpenAIRE

    Wilcox, Gisela

    2005-01-01

    As obesity and diabetes reach epidemic proportions in the developed world, the role of insulin resistance and its consequences are gaining prominence. Understanding the role of insulin in wide-ranging physiological processes and the influences on its synthesis and secretion, alongside its actions from the molecular to the whole body level, has significant implications for much chronic disease seen in Westernised populations today. This review provides an overview of insulin, its history, stru...

  6. Novel recombinant insulin analogue with flexible C-terminus in B chain. NMR structure of biosynthetic engineered A22G-B31K-B32R human insulin monomer in water/acetonitrile solution.

    Science.gov (United States)

    Borowicz, Piotr; Bocian, Wojciech; Sitkowski, Jerzy; Bednarek, Elżbieta; Mikiewicz-Syguła, Diana; Błażej-Sosnowska, Sylwia; Bogiel, Monika; Rusek, Dorota; Kurzynoga, Dariusz; Kozerski, Lech

    2011-11-01

    A tertiary structure of recombinant A22(G)-B31(K)-B32(R)-human insulin monomer (insulin GKR) has been characterized by (1)H, (13)C NMR at natural isotopic abundance using NOESY, TOCSY, (1)H/(13)C-GHSQC, and (1)H/(13)C-GHSQC-TOCSY spectra. Translational diffusion studies indicate the monomer structure in water/acetonitrile (65/35vol.%). CSI analysis confirms existence of secondary structure motifs present in human insulin standard (HIS). Both techniques allow to establish that in this solvent recombinant insulin GKR exists as a monomer. Starting from structures calculated by the program CYANA, two different refinement protocols used molecular dynamics simulated annealing with the program AMBER; in vacuum (AMBER_VC), and including a generalized Born solvent model (AMBER_GB). From these calculations an ensemble of 20 structures of lowest energy was chosen which represents the tertiary structure of studied insulin. Here we present novel insulin with added A22(G) amino acid which interacts with β-turn environment resulting in high flexibility of B chain C-terminus.

  7. Mechanisms Underlying the Onset of Oral Lipid–Induced Skeletal Muscle Insulin Resistance in Humans

    Science.gov (United States)

    Nowotny, Bettina; Zahiragic, Lejla; Krog, Dorothea; Nowotny, Peter J.; Herder, Christian; Carstensen, Maren; Yoshimura, Toru; Szendroedi, Julia; Phielix, Esther; Schadewaldt, Peter; Schloot, Nanette C.; Shulman, Gerald I.; Roden, Michael

    2013-01-01

    Several mechanisms, such as innate immune responses via Toll-like receptor-4, accumulation of diacylglycerols (DAG)/ceramides, and activation of protein kinase C (PKC), are considered to underlie skeletal muscle insulin resistance. In this study, we examined initial events occurring during the onset of insulin resistance upon oral high-fat loading compared with lipid and low-dose endotoxin infusion. Sixteen lean insulin-sensitive volunteers received intravenous fat (iv fat), oral fat (po fat), intravenous endotoxin (lipopolysaccharide [LPS]), and intravenous glycerol as control. After 6 h, whole-body insulin sensitivity was reduced by iv fat, po fat, and LPS to 60, 67, and 48%, respectively (all P < 0.01), which was due to decreased nonoxidative glucose utilization, while hepatic insulin sensitivity was unaffected. Muscle PKCθ activation increased by 50% after iv and po fat, membrane Di-C18:2 DAG species doubled after iv fat and correlated with PKCθ activation after po fat, whereas ceramides were unchanged. Only after LPS, circulating inflammatory markers (tumor necrosis factor-α, interleukin-6, and interleukin-1 receptor antagonist), their mRNA expression in subcutaneous adipose tissue, and circulating cortisol were elevated. Po fat ingestion rapidly induces insulin resistance by reducing nonoxidative glucose disposal, which associates with PKCθ activation and a rise in distinct myocellular membrane DAG, while endotoxin-induced insulin resistance is exclusively associated with stimulation of inflammatory pathways. PMID:23454694

  8. Expression of a synthetic gene encoding human insulin-like growth factor I in cultured mouse fibroblasts.

    OpenAIRE

    Bayne, M L; Cascieri, M A; Kelder, B; Applebaum, J; Chicchi, G; Shapiro, J A; Pasleau, F.; Kopchick, J. J.

    1987-01-01

    A synthetic gene encoding human insulin-like growth factor I (hIGF-I) was assembled and inserted into an expression vector containing the cytomegalovirus immediate early (CMV-IE) transcriptional regulatory region and portions of the bovine growth hormone gene. The recombinant plasmid encodes a 97 amino acid fusion protein containing the first 27 amino acids of the bovine growth hormone precursor and the 70 amino acids of hIGF-I. This plasmid, when transiently introduced into cultured mouse fi...

  9. Long-term exposure to abnormal glucose levels alters drug metabolism pathways and insulin sensitivity in primary human hepatocytes

    Science.gov (United States)

    Davidson, Matthew D.; Ballinger, Kimberly R.; Khetani, Salman R.

    2016-06-01

    Hyperglycemia in type 2 diabetes mellitus has been linked to non-alcoholic fatty liver disease, which can progress to inflammation, fibrosis/cirrhosis, and hepatocellular carcinoma. Understanding how chronic hyperglycemia affects primary human hepatocytes (PHHs) can facilitate the development of therapeutics for these diseases. Conversely, elucidating the effects of hypoglycemia on PHHs may provide insights into how the liver adapts to fasting, adverse diabetes drug reactions, and cancer. In contrast to declining PHH monocultures, micropatterned co-cultures (MPCCs) of PHHs and 3T3-J2 murine embryonic fibroblasts maintain insulin-sensitive glucose metabolism for several weeks. Here, we exposed MPCCs to hypo-, normo- and hyperglycemic culture media for ~3 weeks. While albumin and urea secretion were not affected by glucose level, hypoglycemic MPCCs upregulated CYP3A4 enzyme activity as compared to other glycemic states. In contrast, hyperglycemic MPCCs displayed significant hepatic lipid accumulation in the presence of insulin, while also showing decreased sensitivity to insulin-mediated inhibition of glucose output relative to a normoglycemic control. In conclusion, we show for the first time that PHHs exposed to hypo- and hyperglycemia can remain highly functional, but display increased CYP3A4 activity and selective insulin resistance, respectively. In the future, MPCCs under glycemic states can aid in novel drug discovery and mechanistic investigations.

  10. Blood-based biomarkers of age-associated epigenetic changes in human islets associate with insulin secretion and diabetes.

    Science.gov (United States)

    Bacos, Karl; Gillberg, Linn; Volkov, Petr; Olsson, Anders H; Hansen, Torben; Pedersen, Oluf; Gjesing, Anette Prior; Eiberg, Hans; Tuomi, Tiinamaija; Almgren, Peter; Groop, Leif; Eliasson, Lena; Vaag, Allan; Dayeh, Tasnim; Ling, Charlotte

    2016-03-31

    Aging associates with impaired pancreatic islet function and increased type 2 diabetes (T2D) risk. Here we examine whether age-related epigenetic changes affect human islet function and if blood-based epigenetic biomarkers reflect these changes and associate with future T2D. We analyse DNA methylation genome-wide in islets from 87 non-diabetic donors, aged 26-74 years. Aging associates with increased DNA methylation of 241 sites. These sites cover loci previously associated with T2D, for example, KLF14. Blood-based epigenetic biomarkers reflect age-related methylation changes in 83 genes identified in human islets (for example, KLF14, FHL2, ZNF518B and FAM123C) and some associate with insulin secretion and T2D. DNA methylation correlates with islet expression of multiple genes, including FHL2, ZNF518B, GNPNAT1 and HLTF. Silencing these genes in β-cells alter insulin secretion. Together, we demonstrate that blood-based epigenetic biomarkers reflect age-related DNA methylation changes in human islets, and associate with insulin secretion in vivo and T2D.

  11. Estrogens and Insulin-Like Growth Factor 1 Modulate Neoplastic Cell Growth in Human Cholangiocarcinoma

    Science.gov (United States)

    Alvaro, Domenico; Barbaro, Barbara; Franchitto, Antonio; Onori, Paolo; Glaser, Shannon S.; Alpini, Gianfranco; Francis, Heather; Marucci, Luca; Sterpetti, Paola; Ginanni-Corradini, Stefano; Onetti Muda, Andrea; Dostal, David E.; De Santis, Adriano; Attili, Adolfo F.; Benedetti, Antonio; Gaudio, Eugenio

    2006-01-01

    We investigated the expression of estrogen receptors (ERs), insulin-like growth factor 1 (IGF-1), and IGF-1R (receptor) in human cholangiocarcinoma and cholangiocarcinoma cell lines (HuH-28, TFK-1, Mz-ChA-1), evaluating the role of estrogens and IGF-1 in the modulation of neoplastic cell growth. ER-α, ER-β, IGF-1, and IGF-1R were expressed (immunohistochemistry) in all biopsies (18 of 18) of intrahepatic cholangiocarcinoma. ER-α was expressed (Western blot) only by the HuH-28 cell line (intrahepatic cholangiocarcinoma), whereas ER-β, IGF-1, and IGF-1R were expressed in the three cell lines examined. In serum-deprived HuH-28 cells, serum readmission induced stimulation of cell proliferation that was inhibited by ER and IGF-1R antagonists. 17β-Estradiol and IGF-1 stimulated proliferation of HuH-28 cells to a similar extent to that of MCF7 (breast cancer) but greater than that of TFK-1 and Mz-ChA-1, inhibiting apoptosis and exerting additive effects. These effects of 17β-estradiol and IGF-1 were associated with enhanced protein expression of ER-α, phosphorylated (p)-ERK1/2 and pAKT but with decreased expression of ER-β. Finally, transfection of IGF-1R anti-sense oligonucleotides in HuH-28 cells markedly decreased cell proliferation. In conclusion, human intrahepatic cholangiocarcinomas express receptors for estrogens and IGF-1, which cooperate in the modulation of cell growth and apoptosis. Modulation of ER and IGF-1R could represent a strategy for the management of cholangiocarcinoma. PMID:16936263

  12. Inflammation and insulin resistance induced by trans-10, cis-12 conjugated linoleic acid depend on intracellular calcium levels in primary cultures of human adipocytes

    DEFF Research Database (Denmark)

    Kennedy, Arion; Martinez, Kristina; Chung, Soonkyu;

    2010-01-01

    We previously demonstrated that trans-10, cis-12 (10,12) conjugated linoleic acid (CLA) induced inflammation and insulin resistance in primary human adipocytes by activating nuclear factor kappaB (NFkappaB) and extracellular signal-related kinase (ERK) signaling. In this study, we demonstrated......, and suppression of peroxisome proliferator activated receptor gamma protein levels and insulin-stimulated glucose uptake. These data suggest that 10,12 CLA increases inflammation and insulin resistance in human adipocytes, in part by increasing [Ca2+]i levels, particularly calcium from the ER....

  13. Metformin and insulin receptors

    Energy Technology Data Exchange (ETDEWEB)

    Vigneri, R.; Gullo, D.; Pezzino, V.

    The authors evaluated the effect of metformin (N,N-dimethylbiguanide), a biguanide known to be less toxic than phenformin, on insulin binding to its receptors, both in vitro and in vivo. Specific /sup 125/I-insulin binding to cultured IM-9 human lymphocytes and MCF-7 human breast cancer cells was determined after preincubation with metformin. Specific /sup 125/I-insulin binding to circulating monocytes was also evaluated in six controls, eight obese subjects, and six obese type II diabetic patients before and after a short-term treatment with metformin. Plasma insulin levels and blood glucose were also measured on both occasions. Metformin significantly increased insulin binding in vitro to both IM-9 lymphocytes and MCF-7 cells; the maximum increment was 47.1% and 38.0%, respectively. Metformin treatment significantly increased insulin binding in vivo to monocytes of obese subjects and diabetic patients. Scatchard analysis indicated that the increased binding was mainly due to an increase in receptor capacity. Insulin binding to monocytes of normal controls was unchanged after metformin as were insulin levels in all groups; blood glucose was significantly reduced after metformin only in diabetic patients. These data indicate that metformin increases insulin binding to its receptors in vitro and in vivo. The effect in vivo is observed in obese subjects and in obese type II diabetic patients, paralleling the clinical effectiveness of this antidiabetic agent, and is not due to receptor regulation by circulating insulin, since no variation in insulin levels was recorded.

  14. Maternal serum placental growth hormone, but not human placental lactogen or insulin growth factor-1, is positively associated with fetal growth in the first half of pregnancy

    DEFF Research Database (Denmark)

    Pedersen, N G; Juul, A; Christiansen, M

    2010-01-01

    To investigate if maternal levels of human placental lactogen (hPL), placental growth hormone (PGH) and insulin-like growth factor-1 (IGF-1) are associated with growth rate of the biparietal diameter (BPD) in the first half of pregnancy.......To investigate if maternal levels of human placental lactogen (hPL), placental growth hormone (PGH) and insulin-like growth factor-1 (IGF-1) are associated with growth rate of the biparietal diameter (BPD) in the first half of pregnancy....

  15. Enhanced insulin signaling in human skeletal muscle and adipose tissue following gastric bypass surgery

    DEFF Research Database (Denmark)

    Albers, Peter H; Bojsen-Møller, Kirstine N; Dirksen, Carsten

    2015-01-01

    12 months post-surgery. Adipose tissue from glucose tolerant subjects was the most responsive to RYGB compared to type 2 diabetic patients, whereas changes in skeletal muscle were largely similar in these two groups. In conclusion, an improved molecular insulin sensitive phenotype of skeletal muscle......Roux-en-Y gastric bypass (RYGB) leads to increased peripheral insulin sensitivity. The aim of this study was to investigate the effect of RYGB on expression and regulation of proteins involved in regulation of peripheral glucose metabolism. Skeletal muscle and adipose tissue biopsies from glucose...... tolerant and type 2 diabetic subjects at fasting and during a hyperinsulinemic-euglycemic clamp before as well as 1 week, 3 and 12 months after RYGB were analyzed for relevant insulin effector proteins/signaling components. Improvement in peripheral insulin sensitivity mainly occurred at 12 months post...

  16. A Validated RP-HPLC Method for the Determination of Recombinant Human Insulin in Bulk and Pharmaceutical Dosage Form

    Directory of Open Access Journals (Sweden)

    B. A. Moussa

    2010-01-01

    Full Text Available A modified RP-HPLC method was developed for the quantitative determination of recombinant human insulin in bulk and pharmaceutical dosage form with reduced retention time. Study of the effects of the column temperature, pH of the mobile phase and presence of vial additives (phenol and m-cresol, or impurities (A-21 Disamido on the accuracy of the assay were assessed. Separation was achieved using a Hypersil BDS C-18 column and the mobile phase was composed of solution A (aqueous solution of 28.3 anhydrous Na2SO4g/L, pH 2.3 and solution B (28.5 g anhydrous Na2SO4 g/L in 50:50 mixture of water and acetonitrile, pH 2.3 in a ratio 48:52 (v/v at 45–50 °C. The column temperature was 40 °C, the flow rate was 1 mL/min and detection was performed at 216 nm. The procedures were validated according to international conference on harmonization (ICH guidelines. Recovery study was done applying standard addition technique for further validation of the procedure. The retention time of recombinant human insulin was 19.7 min as compared to 29 min obtained by the reference method. Analytical conditions fluctuations or presence of vial additives or impurities did not show any significant effect on the accuracy of the method. The prepared standard insulin solution in 0.01 N HCl was found to be stable for 5 days. Statistical comparison showed no significant difference between the described method and reference method regarding the accuracy and precision. The modified method can be applied for routine quality control applications for determination of recombinant human insulin.

  17. Short- and long-term metabolic effects of recombinant human IGF-I treatment in patients with severe insulin resistance and diabetes mellitus

    DEFF Research Database (Denmark)

    Vestergaard, H; Rossen, M; Urhammer, S A

    1997-01-01

    the metabolic and hormonal responses to an unchanged insulin therapy with the addition of a subcutaneous administration of recombinant human IGF-I (rhIGF-I) during (a) a short-term (2 weeks) period with rhIGF-I given twice a day in a high dose (80 micrograms/kg body weight) in four patients with extreme insulin....... In conclusion: 2 weeks of high-dose rhIGF-I therapy in insulin-treated patients with severe insulin resistance has a marked lowering effect on fasting plasma glucose and serum insulin levels whereas the metabolic and glycaemic effects of 10 weeks of treatment with low-dose rhIGF-I may be modest and transient....

  18. Insulin enhances apoptosis induced by cisplatin in human esophageal squamous cell carcinoma EC9706 cells related to inhibition of autophagy

    Institute of Scientific and Technical Information of China (English)

    Yang Yang; Wen Fengbiao; Dang Lifeng; Fan Yuxia; Liu Donglei; Wu Kai; Zhao Song

    2014-01-01

    Background Chemoresistance is common among patients with esophageal squamous cell carcinoma (ESCC).We investigated the effect and mechanism of insulin on enhancing anticancer functions of cisplatin in human esophageal cancer cell line EC9706.Methods The viability of EC9706 cells exposed to cisplatin was assessed using MTT assay.The times T1,when the number of living cells reached a plateau and T2,when the number of living cells reached a new plateau after the addition of insulin were found.T1 and T2 plateau cells were stained by Annexin V-FITC/PI and monodansylcadaverin (MDC).Fluorescent microscopy was used to observe the expression of apoptosis and autophagy intuitively.Apoptotic ratio and fluorescent intensity were analysed by flow cytometry (FCM) quantitatively.Western blotting analysis was used to estimate the protein expression levels of AKT,mTOR,PI3K,PTEN,autophage related indicator LC3-Ⅱ and autophage related protein Beclin1 changes that occurred in the course of treatment.Results A larger number of typical autophagosomes were detected in EC9706 cells exposed to cisplatin.Insulin can increase the apoptosis induced by cisplatin.Apoptotic ratio of T1 plateau cells ((32.6±4.3)%) is significantly less than T2 plateau ((47.5±5.6)%).MDC fluorescent intensity at T1 plateau (104.9±13.2) was significantly higher than intensity at T2 plateau (82.6±10.3).After cotreatment with insulin,the expression level of LC3-Ⅱ,Beclin1 and PTEN in T2 plateau cells were significantly downregulated,but AKT,mTOR and PI3K expressions significantly upregulated compared with T1 plateau.Conclusions Insulin could enhance cisplatin-induced apoptosis in human esophageal squamous cell carcinoma EC9706 cells related to inhibition of autophagy.The activation of PI3K/Akt/mTOR signaling pathway induced by insulin resulted in the suppression of autophagy in EC9706 cells,which may be attributed to the anticancer effects of cisplatin.

  19. Insulin but not glucagon gene is silenced in human pancreas-derived mesenchymal stem cells.

    Science.gov (United States)

    Wilson, Leah M; Wong, Stephen H K; Yu, Ningpu; Geras-Raaka, Elizabeth; Raaka, Bruce M; Gershengorn, Marvin C

    2009-11-01

    We previously characterized human islet-derived precursor cells (hIPCs) as a specific type of mesenchymal stem cell capable of differentiating to insulin (INS)- and glucagon (GCG)-expressing cells. However, during proliferative expansion, INS transcript becomes undetectable and then cannot be induced, a phenomenon consistent with silencing of the INS gene. We explored this possibility by determining whether ectopic expression of transcription factors known to induce transcription of this gene in beta cells, pancreatic and duodenal homeobox factor 1 (Pdx1), V-maf musculoaponeurotic fibrosarcoma oncogene homolog A (Mafa), and neurogenic differentiation 1 (Neurod1), would activate INS gene expression in long-term hIPC cultures. Coexpression of all three transcription factors had little effect on INS mRNA levels but unexpectedly increased GCG mRNA at least 100,000-fold. In contrast to the endogenous promoter, an exogenous rat INS promoter was activated by expression of Pdx1 and Mafa in hIPCs. Chromatin immunoprecipitation (ChIP) assays using antibodies directed at posttranslationally modified histones show that regions of the INS and GCG genes have similar levels of activation-associated modifications but the INS gene has higher levels of repression-associated modifications. Furthermore, the INS gene was found to be less accessible to micrococcal nuclease digestion than the GCG gene. Lastly, ChIP assays show that exogenously expressed Pdx1 and Mafa bind at very low levels to the INS promoter and at 20- to 25-fold higher levels to the GCG promoter in hIPCs. We conclude that the INS gene in hIPCs is modified epigenetically ("silenced") so that it is resistant to activation by transcription factors.

  20. A biphasic scaffold based on silk and bioactive ceramic with stratified properties for osteochondral tissue regeneration.

    Science.gov (United States)

    Li, Jiao Jiao; Kim, Kyungsook; Roohani-Esfahani, Seyed-Iman; Guo, Jin; Kaplan, David L; Zreiqat, Hala

    2015-07-14

    Significant clinical challenges encountered in the effective long-term treatment of osteochondral defects have inspired advancements in scaffold-based tissue engineering techniques to aid repair and regeneration. This study reports the development of a biphasic scaffold produced via a rational combination of silk fibroin and bioactive ceramic with stratified properties to satisfy the complex and diverse regenerative requirements of osteochondral tissue. Structural examination showed that the biphasic scaffold contained two phases with different pore morphologies to match the cartilage and bone segments of osteochondral tissue, which were joined at a continuous interface. Mechanical assessment showed that the two phases of the biphasic scaffold imitated the load-bearing behaviour of native osteochondral tissue and matched its compressive properties. In vitro testing showed that different compositions in the two phases of the biphasic scaffold could direct the preferential differentiation of human mesenchymal stem cells towards the chondrogenic or osteogenic lineage. By featuring simple and reproducible fabrication and a well-integrated interface, the biphasic scaffold strategy established in this study circumvented the common problems experienced with integrated scaffold designs and could provide an effective approach for the regeneration of osteochondral tissue.

  1. In vitro cultivation of human fetal pancreatic ductal stem cells and their differentiation into insulin-producing cells

    Institute of Scientific and Technical Information of China (English)

    Zhong-Xiang Yao; Mao-Lin Qin; Jian-Jun Liu; Xing-Shu Chen; De-Shan Zhou

    2004-01-01

    AIM: To isolate, culture and identify the human fetal pancreatic ductal stem cells in vitro, and to observe the potency of these multipotential cells differentiation into insulin-producing cells.METHODS: The human fetal pancreas was digested by 1 g/L collagease type Ⅳ and then 2.5 g/L trypsin was used to isolate the pancreatic ducta stem cells, followed by culture in serum-free, glucose-free DMEM media with some additional chemical substrates in vitro (according to the different Stage). The cells were induced by glucose-free (control),5 mmol/L, 17.8 mmol/L and 25 mmol/L glucose, respectively.The cell types of differentiated cells were identified using immunocytochemical staining.RESULTS: The shape of human fetal pancreatic ductal stem cells culturedin vitro was firstly fusiform in the first 2 wk,and became monolayer and cobblestone pattern after another 3 to 4 wk. After induced and differentiated by the glucose of different concentrations for another 1 to 2 wk,the cells formed the pancreatic islet-like structures. The identification and potency of these cells were then identified by using the pancreatic ductal stem cell marker, cytokeratin-19 (CK-19), pancreatic β cell marker, insulin and pancreatic α cell marker, glucagons with immunocytochemical staining.At the end of the second week, 95.2% of the cells were positive for CK-19 immunoreactivity. Up to 22.7% of the cells induced by glucose were positive for insulin immunoreactivity, and less than 3.8% of the cells were positive for glucagon immunoreactivity in pancreatic isletlike structures. The positive ratio of immunoreactive staining was dependent on the concentration of glucose, and it was observed that the 17.8 mmol/L glucose stimulated effectively to produce insulin- and glucagons-producing cells.CONCLUSION: The human fetal pancreatic ductal stem cells are capable of proliferation in vitro. These cells have multidifferentiation potential and can be induced by glucose and differentiated into insulin

  2. Identification of the ectonucleotidases expressed in mouse, rat, and human Langerhans islets: potential role of NTPDase3 in insulin secretion.

    Science.gov (United States)

    Lavoie, Elise G; Fausther, Michel; Kauffenstein, Gilles; Kukulski, Filip; Künzli, Beat M; Friess, Helmut; Sévigny, Jean

    2010-10-01

    Extracellular nucleotides and adenosine regulate endocrine pancreatic functions such as insulin secretion by Langerhans islet β-cells via the activation of specific P2 and P1 receptors. Membrane-bound ectonucleotidases regulate the local concentration of these ligands and consequently control the activation of their receptors. The objective of this study was to identify and localize the major ectonucleotidases, namely NTPDases and ecto-5'-nucleotidase, present in the endocrine pancreas. In addition, the potential implication of ecto-ATPase activity on insulin secretion was investigated in the rat β-cell line INS-1 (832/13). The localization of ectonucleotidase activity and protein was carried out in situ by enzyme histochemistry and immunolocalization in mouse, rat, and human pancreas sections. NTPDase1 was localized in all blood vessels and acini, and NTPDase2 was localized in capillaries of Langerhans islets and in peripheral conjunctive tissue, whereas NTPDase3 was detected in all Langerhans islet cell types. Interestingly, among the mammalian species tested, ecto-5'-nucleotidase was present only in rat Langerhans islet cells, where it was coexpressed with NTPDase3. Notably, the inhibition of NTPDase3 activity by BG0136 and NF279 facilitated insulin release from INS-1 (832/13) cells under conditions of low glycemia, probably by affecting P2 receptor activation. NTPDase3 activity also regulated the inhibitory effect of exogenous ATP in the presence of a high glucose concentration most likely by controlling adenosine production. In conclusion, all pancreatic endocrine cells express NTPDase3 that was shown to modulate insulin secretion in rat INS-1 (832/13) β-cells. Ecto-5'-nucleotidase is expressed in rat Langerhans islet cells but absent in human and mouse endocrine cells.

  3. The in vitro effects of dexamethasone, insulin and triiodothyronine on degenerative human intervertebral disc cells under normoxic and hypoxic conditions

    Directory of Open Access Journals (Sweden)

    A Bertolo

    2011-02-01

    Full Text Available Degeneration of intervertebral discs (IVD is one of the main causes of back pain and tissue engineering has been proposed as a treatment. Tissue engineering requires the use of highly expensive growth factors, which might, in addition, lack regulatory approval for human use. In an effort to find readily available differentiation factors, we tested three molecules – dexamethasone, triiodothyronine (T3 and insulin – on human IVD cells isolated after surgery, expanded in vitro and transferred into alginate beads. Triplicates containing 40 ng/ml dexamethasone, 10 nM T3 and 10 µg/ml insulin, together with a positive control (10 ng/mL transforming growth factor (TGF-beta 1, were sampled weekly over six weeks and compared to a negative control. Furthermore, we compared the results to cultures with optimized chondrogenic media and under hypoxic condition (2% O2. Glycosaminoglycan (GAG determination by Alcian Blue assay and histological staining showed dexamethasone to be more effective than T3 and insulin, but less than TGF-beta1. DNA quantification showed that only dexamethasone stimulated cell proliferation. qPCR demonstrated that TGF-beta1 and the optimized chondrogenic groups increased the expression of collagen type II, while aggrecan was stimulated in cultures containing dexamethasone. Hypoxia increased GAG accumulation, collagen type II and aggrecan expression, but had no effect on or even lowered cell number. In conclusion, dexamethasone is a valuable and cost-effective molecule for chondrogenic and viability induction of IVD cells under normoxic and hypoxic conditions, while insulin and T3 did not show significant differences.

  4. Insulin resistance is associated with MCP1-mediated macrophage accumulation in skeletal muscle in mice and humans.

    Directory of Open Access Journals (Sweden)

    David Patsouris

    Full Text Available Inflammation is now recognized as a major factor contributing to type 2 diabetes (T2D. However, while the mechanisms and consequences associated with white adipose tissue inflammation are well described, very little is known concerning the situation in skeletal muscle. The aim of this study was to investigate, in vitro and in vivo, how skeletal muscle inflammation develops and how in turn it modulates local and systemic insulin sensitivity in different mice models of T2D and in humans, focusing on the role of the chemokine MCP1. Here, we found that skeletal muscle inflammation and macrophage markers are increased and associated with insulin resistance in mice models and humans. In addition, we demonstrated that intra-muscular TNFα expression is exclusively restricted to the population of intramuscular leukocytes and that the chemokine MCP1 was associated with skeletal muscle inflammatory markers in these models. Furthermore, we demonstrated that exposure of C2C12 myotubes to palmitate elevated the production of the chemokine MCP1 and that the muscle-specific overexpression of MCP1 in transgenic mice induced the local recruitment of macrophages and altered local insulin sensitivity. Overall our study demonstrates that skeletal muscle inflammation is clearly increased in the context of T2D in each one of the models we investigated, which is likely consecutive to the lipotoxic environment generated by peripheral insulin resistance, further increasing MCP1 expression in muscle. Consequently, our results suggest that MCP1-mediated skeletal muscle macrophages recruitment plays a role in the etiology of T2D.

  5. Negative regulation of human growth hormone gene expression by insulin is dependent on hypoxia-inducible factor binding in primary non-tumor pituitary cells.

    Science.gov (United States)

    Vakili, Hana; Jin, Yan; Cattini, Peter A

    2012-09-28

    Insulin controls growth hormone (GH) production at multiple levels, including via a direct effect on pituitary somatotrophs. There are no data, however, on the regulation of the intact human (h) GH gene (hGH1) by insulin in non-tumor pituitary cells, but the proximal promoter region (nucleotides -496/+1) responds negatively to insulin in transfected pituitary tumor cells. A DNA-protein interaction was also induced by insulin at nucleotides -308/-235. Here, we confirmed the presence of a hypoxia-inducible factor 1 (HIF-1) binding site within these sequences (-264/-259) and investigated whether HIF-1 is associated with insulin regulation of "endogenous" hGH1. In the absence of primary human pituitary cells, transgenic mice expressing the intact hGH locus in a somatotroph-specific manner were generated. A significant and dose-dependent decrease in hGH and mouse GH RNA levels was detected in primary pituitary cell cultures from these mice with insulin treatment. Increasing HIF-1α availability with a hypoxia mimetic significantly decreased hGH RNA levels and was accompanied by recruitment of HIF-1α to the hGH1 promoter in situ as seen with insulin. Both inhibition of HIF-1 DNA binding by echinomycin and RNA interference of HIF-1α synthesis blunted the negative effect of insulin on hGH1 but not mGH. The insulin response is also sensitive to histone deacetylase inhibition/trichostatin A and associated with a decrease in H3/H4 hyperacetylation in the proximal hGH1 promoter region. These data are consistent with HIF-1-dependent down-regulation of hGH1 by insulin via chromatin remodeling specifically in the proximal promoter region.

  6. Biphasic Dependence of Glioma Survival and Cell Migration on CD44 Expression Level.

    Science.gov (United States)

    Klank, Rebecca L; Decker Grunke, Stacy A; Bangasser, Benjamin L; Forster, Colleen L; Price, Matthew A; Odde, Thomas J; SantaCruz, Karen S; Rosenfeld, Steven S; Canoll, Peter; Turley, Eva A; McCarthy, James B; Ohlfest, John R; Odde, David J

    2017-01-03

    While several studies link the cell-surface marker CD44 to cancer progression, conflicting results show both positive and negative correlations with increased CD44 levels. Here, we demonstrate that the survival outcomes of genetically induced glioma-bearing mice and of high-grade human glioma patients are biphasically correlated with CD44 level, with the poorest outcomes occurring at intermediate levels. Furthermore, the high-CD44-expressing mesenchymal subtype exhibited a positive trend of survival with increased CD44 level. Mouse cell migration rates in ex vivo brain slice cultures were also biphasically associated with CD44 level, with maximal migration corresponding to minimal survival. Cell simulations suggest that cell-substrate adhesiveness is sufficient to explain this biphasic migration. More generally, these results highlight the potential importance of non-monotonic relationships between survival and biomarkers associated with cancer progression.

  7. IFN-β is a potent inhibitor of insulin and insulin like growth factor stimulated proliferation and migration in human pancreatic cancer cells

    NARCIS (Netherlands)

    S. Booy (Stephanie); C.H.J. van Eijck (Casper); J.A.M.J.L. Janssen (Joseph); F. Dogan (Fadime); P.M. van Koetsveld (Peter); L.J. Hofland (Leo)

    2015-01-01

    textabstractIntroduction: Pancreatic cancer is a highly aggressive malignancy with few treatment options. The overexpression of several growth factors, including insulin and insulin-like growth factors (IGFs), can underlie the aggressive nature of this disease. Previous research has demonstrated pot

  8. Insulin does not stimulate muscle protein synthesis during increased plasma branched-chain amino acids alone but still decreases whole body proteolysis in humans.

    Science.gov (United States)

    Everman, Sarah; Meyer, Christian; Tran, Lee; Hoffman, Nyssa; Carroll, Chad C; Dedmon, William L; Katsanos, Christos S

    2016-10-01

    Insulin stimulates muscle protein synthesis when the levels of total amino acids, or at least the essential amino acids, are at or above their postabsorptive concentrations. Among the essential amino acids, branched-chain amino acids (BCAA) have the primary role in stimulating muscle protein synthesis and are commonly sought alone to stimulate muscle protein synthesis in humans. Fourteen healthy young subjects were studied before and after insulin infusion to examine whether insulin stimulates muscle protein synthesis in relation to the availability of BCAA alone. One half of the subjects were studied in the presence of postabsorptive BCAA concentrations (control) and the other half in the presence of increased plasma BCAA (BCAA). Compared with that prior to the initiation of the insulin infusion, fractional synthesis rate of muscle protein (%/h) did not change (P > 0.05) during insulin in either the control (0.04 ± 0.01 vs 0.05 ± 0.01) or the BCAA (0.05 ± 0.02 vs. 0.05 ± 0.01) experiments. Insulin decreased (P BCAA (0.89 ± 0.07 vs 0.61 ± 0.03) experiments, but the change was not different between the two experiments (P > 0.05). In conclusion, insulin does not stimulate muscle protein synthesis in the presence of increased circulating levels of plasma BCAA alone. Insulin's suppressive effect on proteolysis is observed independently of the levels of circulating plasma BCAA.

  9. Insulin fails to enhance mTOR phosphorylation, mitochondrial protein synthesis, and ATP production in human skeletal muscle without amino acid replacement.

    Science.gov (United States)

    Barazzoni, Rocco; Short, Kevin R; Asmann, Yan; Coenen-Schimke, Jill M; Robinson, Matthew M; Nair, K Sreekumaran

    2012-11-01

    Systemic insulin administration causes hypoaminoacidemia by inhibiting protein degradation, which may in turn inhibit muscle protein synthesis (PS). Insulin enhances muscle mitochondrial PS and ATP production when hypoaminoacidemia is prevented by exogenous amino acid (AA) replacement. We determined whether insulin would stimulate mitochondrial PS and ATP production in the absence of AA replacement. Using l-[1,2-¹³C]leucine as a tracer, we measured the fractional synthetic rate of mitochondrial as well as sarcoplasmic and mixed muscle proteins in 18 participants during sustained (7-h) insulin or saline infusion (n = 9 each). We also measured muscle ATP production, mitochondrial enzyme activities, mRNA levels of mitochondrial genes, and phosphorylation of signaling proteins regulating protein synthesis. The concentration of circulating essential AA decreased during insulin infusion. Mitochondrial, sarcoplasmic, and mixed muscle PS rates were also lower during insulin (2-7 h) than during saline infusions despite increased mRNA levels of selected mitochondrial genes. Under these conditions, insulin did not alter mitochondrial enzyme activities and ATP production. These effects were associated with enhanced phosphorylation of Akt but not of protein synthesis activators mTOR, p70(S6K), and 4EBP1. In conclusion, sustained physiological hyperinsulinemia without AA replacement did not stimulate PS of mixed muscle or protein subfractions and did not alter muscle mitochondrial ATP production in healthy humans. These results support that insulin and AA act in conjunction to stimulate muscle mitochondrial function and mitochondrial protein synthesis.

  10. Counter-regulatory hormone responses to spontaneous hypoglycaemia during treatment with insulin Aspart or human soluble insulin. A double-blinded randomised cross-over study

    DEFF Research Database (Denmark)

    Brock-Jacobsen, Iben; Vind, B F; Korsholm, L;

    2011-01-01

    .9 0.1 events per patient per week, ns), nocturnal hypoglycaemia, severe hypoglycaemic events, dosages of bolus insulin (31.8 0.4 vs. 30.0 0.6 IU day)1, ns), or NPH insulin (26.7 1.8 vs. 26.0 1.7 IU day)1, ns) or in patients satisfaction (ns). Modest differences existed in the counter......-regulatory responses regarding growth hormone, glucagon and ghrelin whereas no differences were found in relation to free fatty acid, cortisol, insulin-like growth factor (IGF)-I, IGF-II and IGF-binding proteins 1 and 2. Treatment with insulin Aspart resulted in well-defined peaks in serum insulin concentrations...

  11. Binding of insulin-like growth factors to Tera-2 human embryonal carcinoma cells during differentiation.

    Science.gov (United States)

    Fleck, J F; Sledge, G W; Benenati, S V; Frolik, C A; Roth, B J; Hirsch, K S

    1991-08-15

    Differentiation of Tera-2 human embryonal carcinoma cells by exposure to 2.1 mM alpha-difluoromethylornithine resulted in changes in morphology, a decrease in growth rate, and changes in the expression of SSEA-1 differentiation antigen. While the binding of 125I-insulin-like growth factor I (IGF-I) remained relatively constant during differentiation, binding of 125I-IGF-II increased 2-3-fold. Further, the binding of IGF-II was 87 times greater than IGF-I in both undifferentiated and differentiated cells. Undifferentiated Tera-2 cells exhibited a single class of binding sites for both IGF-I (KD = 1.2 nM, 7.0 x 10(3) sites/cell) and IGF-II (KD = 8.3 nM, 3.4 x 10(5) sites/cell). Following differentiation, IGF-I continued to bind to a single class of binding sites (KD 1.0 nM, 6.7 x 10(3) sites/cell) whereas IGF-II bound to both high-affinity sites (KDH 0.3 nM, 2.2 x 10(5) sites/cell) and low-affinity sites (KDL 15.1 nM, 1.6 x 10(7) sites/cell). The binding of iodinated IGF-II was blocked by unlabeled IGF-II but not IGF-I. In contrast, 125I-IGF-I binding was prevented by either IGF-I or IGF-II. Affinity cross-linking experiments demonstrated the presence of both type I and type II IGF receptors along with a number of IGF binding proteins. IGF-I failed to stimulate the incorporation of [3H]thymidine in both undifferentiated and differentiated cells. Although IGF-II caused a significant increase in [3H]thymidine incorporation in both undifferentiated and differentiated Tera-2 cells, the magnitude of the response and the sensitivity of the cells to IGF-II stimulation was diminished following differentiation. The observed changes in IGF-II binding, which occur in conjunction with cellular differentiation, may be an important feature of the expression of the differentiated phenotype by human germ cell tumors.

  12. Effects of Lactobacillus acidophilus NCFM on insulin sensitivity and the systemic inflammatory response in human subjects

    DEFF Research Database (Denmark)

    Andreasen, Anne Sofie; Larsen, Nadja; Pedersen-Skovsgaard, Theis

    2010-01-01

    According to animal studies, intake of probiotic bacteria may improve glucose homeostasis. We hypothesised that probiotic bacteria improve insulin sensitivity by attenuating systemic inflammation. Therefore, the effects of oral supplementation with the probiotic bacterium Lactobacillus acidophilus...... course with either L. acidophilus NCFM or placebo. L. acidophilus was detected in stool samples by denaturating gradient gel electrophoresis and real-time PCR. Separated by the 4-week intervention period, two hyperinsulinaemic-euglycaemic clamps were performed to estimate insulin sensitivity. Furthermore......, the systemic inflammatory response was evaluated by subjecting the participants to Escherichia coli lipopolysaccharide injection (0·3 ng/kg) before and after the treatment course. L. acidophilus NCFM was detected in 75 % of the faecal samples after treatment with the probiotic bacterium. Insulin sensitivity...

  13. Unprecedented high insulin secretion in a healthy human subject after intravenous glucagon-like peptide-1

    DEFF Research Database (Denmark)

    Knop, Filip K; Lund, Asger; Madsbad, Sten

    2014-01-01

    to as one of the most insulinotropic substances known. CASE PRESENTATION: Plasma insulin and C-peptide concentrations were measured in a healthy Caucasian male (age: 53 years; body mass index: 28.6 kg/m2; fasting plasma glucose: 5.7 mM; 2 h plasma glucose value following 75 g-oral glucose tolerance test: 3...... insulin and C-peptide responses were observed during meal test (peak concentrations: 300 and 3,278 pM) and glucagon test (peak concentrations: 250 and 2,483 pM). During the hyperglycaemic clamp with continuous intravenous infusion of GLP-1 the subject exhibited plasma insulin and C-peptide concentrations...

  14. Differentiating of banked human umbilical cord blood-derived mesenchymal stem cells into insulin-secreting cells.

    Science.gov (United States)

    Phuc, Pham Van; Nhung, Truong Hai; Loan, Dang Thi Tung; Chung, Doan Chinh; Ngoc, Phan Kim

    2011-01-01

    Umbilical cord blood (UCB)-derived mesenchymal stem cells (MSCs) are multipotent cells. They are able to differentiate into functional cells from not only mesoderm but also endoderm. Many researches showed that cells derived from fresh human UCB could transdifferentiate into insulin-secreting cells. In this study, transdifferentiating potential of cryopreserved human UCB-derived MSCs into insulin-secreting cell was investigated. Fresh human UCB was enriched the mononuclear cells by Ficoll-Paque centrifugation. The mononuclear cell population was cryopreserved in cryo-medium containing Iscove's modified Dulbecco's media (IMDM) with 10% DMSO at -196°C for 1 yr. After thawing, mononuclear cells were cultured to isolate MSCs in medium IMDM with 20% FBS supplemented with growth factors. At the fifth passages, MSCs were confirmed by flow cytometry about expression of CD13, CD14, CD34, CD45, CD166, and HLA-DR markers; after that, they were induced to differentiate into adipocytes and osteoblasts. After inducing with specific medium for islet differentiation, there were many clusters of cell like islet at day 14-28. Using real-time reverse transcription polymerase chain reaction (RT-PCR) to analyze the expression of functional genes, the result showed that Nestin, Pdx-1, Ngn3, Ils-1, Pax6, Pax4, Nkx2.2, Nkx6.1, Glut-2, Insulin genes expressed. The results showed that MSCs derived from banked cord blood can differentiate into functional pancreatic islet-like cells in vitro. If human MSCs, especially MSCs from banked cord blood of diabetes patients themselves can be isolated, proliferated, differentiated into functional pancreatic islet-like cells, and transplanted back into them (autologous transplantation), their high-proliferation potency and rejection avoidance will provide one promising therapy for diabetes.

  15. Vasodilator effects of L-arginine are stereospecific and augmented by insulin in humans.

    Science.gov (United States)

    Dallinger, Susanne; Sieder, Anna; Strametz, Jeanette; Bayerle-Eder, Michaela; Wolzt, Michael; Schmetterer, Leopold

    2003-06-01

    The amino acid l-arginine, the precursor of nitric oxide (NO) synthesis, induces vasodilation in vivo, but the mechanism behind this effect is unclear. There is, however, some evidence to assume that the l-arginine membrane transport capacity is dependent on insulin plasma levels. We hypothesized that vasodilator effects of l-arginine may be dependent on insulin plasma levels. Accordingly, we performed two randomized, double-blind crossover studies in healthy male subjects. In protocol 1 (n = 15), subjects received an infusion of insulin (6 mU x kg(-1) x min(-1) for 120 min) or placebo and, during the last 30 min, l-arginine or d-arginine (1 g/min for 30 min) x In protocol 2 (n = 8), subjects received l-arginine in stepwise increasing doses in the presence (1.5 mU x kg(-1) x min(-1)) or absence of insulin. Renal plasma flow and glomerular filtration rate were assessed by the para-aminohippurate and inulin plasma clearance methods, respectively. Pulsatile choroidal blood flow was assessed with laser interferometric measurement of fundus pulsation, and mean flow velocity in the ophthalmic artery was measured with Doppler sonography. l-arginine, but not d-arginine, significantly increased renal and ocular hemodynamic parameters. Coinfusion of l-arginine with insulin caused a dose-dependent leftward shift of the vasodilator effect of l-arginine. This stereospecific renal and ocular vasodilator potency of l-arginine is enhanced by insulin, which may result from facilitated l-arginine membrane transport, enhanced intracellular NO formation, or increased NO bioavailability.

  16. Reduced malonyl-CoA content in recovery from exercise correlates with improved insulin-stimulated glucose uptake in human skeletal muscle

    DEFF Research Database (Denmark)

    Frøsig, Christian; Roepstorff, Carsten; Brandt, Nina

    2009-01-01

    This study evaluated whether improved insulin-stimulated glucose uptake in recovery from acute exercise coincides with reduced malonyl-CoA (MCoA) content in human muscle. Furthermore, we investigated whether a high-fat diet [65 energy-% (Fat)] would alter the content of MCoA and insulin action...... to be compromised, although to a minor extent, by the Fat diet. Collectively, this study indicates that reduced muscle MCoA content in recovery from exercise may be part of the adaptive response leading to improved insulin action on glucose uptake after exercise in human muscle....... legs during a euglycemic-hyperinsulinemic clamp. Muscle biopsies were obtained in both legs before and after the clamp. Four hours after exercise, insulin-stimulated glucose uptake was improved (approximately 70%, P

  17. Impact of the Xba1-polymorphism of the human muscle glycogen synthase gene on parameters of the insulin resistance syndrome in a Danish twin population

    DEFF Research Database (Denmark)

    Fenger, M; Poulsen, P; Beck-Nielsen, H;

    2000-01-01

    : The Xba1-polymorphism of the human muscle glycogen synthase gene is correlated to insulin resistance and to diastolic blood pressure. The polymorphism does not involve any known transcription factor or any structural change in GYS1, and these correlations are therefore most probably caused by linkage......AIMS: To establish the impact on the insulin resistance syndrome of the intron 14 Xba1-polymorphism in human muscle glycogen synthase (GYS1). METHODS: Parameters related to the insulin resistance syndrome were measured in 244 monozygotic twins and 322 dizygotic twins with or without impaired...... and the remainder had the genotype A1A2. No A2A2-genotypes were detected. In 11 genotypic discordant dizygotic twin pairs the insulin resistance was significantly increased in the twins carrying the A1A2 genotype regardless of sex (HOMA index 1.81 (A1A1) vs. 2.57 (A1A2), P

  18. The effect of 30 months of low-dose replacement therapy with recombinant human growth hormone (rhGH) on insulin and C-peptide kinetics, insulin secretion, insulin sensitivity, glucose effectiveness, and body composition in GH-deficient adults

    DEFF Research Database (Denmark)

    Rosenfalck, A M; Maghsoudi, S; Fisker, S

    2000-01-01

    the insulin sensitivity index, calculated from the frequently sampled iv glucose tolerance test, only decreased slightly. The clearance of C-peptide and insulin increased 100% and 60%, respectively, and the prehepatic insulin secretion was tripled during rhGH treatment; but related to the impairment...... an increase in lean body mass and a reduction of fat mass. Therefore, rhGH treatment may precipitate diabetes in some patients already susceptible to the disorder....

  19. Glutamine:fructose-6-phosphate amidotransferase activity in cultured human skeletal muscle cells: relationship to glucose disposal rate in control and non-insulin-dependent diabetes mellitus subjects and regulation by glucose and insulin.

    OpenAIRE

    1996-01-01

    We examined the activity of the rate-limiting enzyme for hexosamine biosynthesis, glutamine:fructose-6-phosphate amidotransferase (GFA) in human skeletal muscle cultures (HSMC), from 17 nondiabetic control and 13 subjects with non-insulin-dependent diabetes. GFA activity was assayed from HSMC treated with low (5 mM) or high (20 mM) glucose and low (22 pM) or high (30 microM) concentrations of insulin. In control subjects GFA activity decreased with increasing glucose disposal rate (r = -0.68,...

  20. Identification of direct and indirect social network effects in the pathophysiology of insulin resistance in obese human subjects.

    Directory of Open Access Journals (Sweden)

    Christian H C A Henning

    Full Text Available OBJECTIVE: The aim of the present study was to examine to what extent different social network mechanisms are involved in the pathogenesis of obesity and insulin-resistance. DESIGN: We used nonparametric and parametric regression models to analyse whether individual BMI and HOMA-IR are determined by social network characteristics. SUBJECTS AND METHODS: A total of 677 probands (EGO and 3033 social network partners (ALTER were included in the study. Data gathered from the probands include anthropometric measures, HOMA-IR index, health attitudes, behavioural and socio-economic variables and social network data. RESULTS: We found significant treatment effects for ALTERs frequent dieting (p<0.001 and ALTERs health oriented nutritional attitudes (p<0.001 on EGO's BMI, establishing a significant indirect network effect also on EGO's insulin resistance. Most importantly, we also found significant direct social network effects on EGO's insulin resistance, evidenced by an effect of ALTERs frequent dieting (p = 0.033 and ALTERs sport activities (p = 0.041 to decrease EGO's HOMA-IR index independently of EGO's BMI. CONCLUSIONS: Social network phenomena appear not only to be relevant for the spread of obesity, but also for the spread of insulin resistance as the basis for type 2 diabetes. Attitudes and behaviour of peer groups influence EGO's health status not only via social mechanisms, but also via socio-biological mechanisms, i.e. higher brain areas might be influenced not only by biological signals from the own organism, but also by behaviour and knowledge from different human individuals. Our approach allows the identification of peer group influence controlling for potential homophily even when using cross-sectional observational data.

  1. Effects of Acute Pinitol Supplementation on Plasma Pinitol Concentration, Whole Body Glucose Tolerance, and Activation of the Skeletal Muscle Insulin Receptor in Older Humans

    OpenAIRE

    Stull, A. J.; Wood, K V; Thyfault, J. P.; Campbell, W.W.

    2009-01-01

    Limited research with rodents and humans suggests that oral ingestion of pinitol (3-O-methyl-d-chiro-inositol) might positively influence glucose tolerance. This double-blinded, placebo-controlled, and cross-over study assessed the effects of acute pinitol supplementation on plasma pinitol concentration, glucose tolerance, insulin sensitivity, and activation of the skeletal muscle insulin receptor. Fifteen older, nondiabetic subjects (62 ± 1 years, mean ± SEM) completed four, 1-day trials. Su...

  2. Metal separations using aqueous biphasic partitioning systems

    Energy Technology Data Exchange (ETDEWEB)

    Chaiko, D.J.; Zaslavsky, B.; Rollins, A.N.; Vojta, Y.; Gartelmann, J.; Mego, W. [Argonne National Lab., IL (United States). Chemical Technology Div.

    1996-05-01

    Aqueous biphasic extraction (ABE) processes offer the potential for low-cost, highly selective separations. This countercurrent extraction technique involves selective partitioning of either dissolved solutes or ultrafine particulates between two immiscible aqueous phases. The extraction systems that the authors have studied are generated by combining an aqueous salt solution with an aqueous polymer solution. They have examined a wide range of applications for ABE, including the treatment of solid and liquid nuclear wastes, decontamination of soils, and processing of mineral ores. They have also conducted fundamental studies of solution microstructure using small angle neutron scattering (SANS). In this report they review the physicochemical fundamentals of aqueous biphase formation and discuss the development and scaleup of ABE processes for environmental remediation.

  3. Caffeine's impairment of insulin-mediated glucose disposal cannot be solely attributed to adrenaline in humans

    DEFF Research Database (Denmark)

    Battram, D S; Graham, T E; Dela, F

    2007-01-01

    Caffeine (CAF) impedes insulin-mediated glucose disposal (IMGD) and increases plasma adrenaline concentrations ([ADR]; 0.6 nm). While the antagonism of ADR abolishes the CAF effect, infusion of ADR (0.75 nm) has no effect on IMGD. We have now examined CAF and ADR in concert to determine whether...

  4. Insulin, catecholamines, glucose and antioxidant enzymes in oxidative damage during different loads in healthy humans.

    Science.gov (United States)

    Koska, J; Blazícek, P; Marko, M; Grna, J D; Kvetnanský, R; Vigas, M

    2000-01-01

    Exercise, insulin-induced hypoglycemia and oral glucose loads (50 g and 100 g) were used to compare the production of malondialdehyde and the activity of antioxidant enzymes in healthy subjects. Twenty male volunteers participated in the study. Exercise consisted of three consecutive work loads on a bicycle ergometer of graded intensity (1.5, 2.0, and 2.5 W/kg, 6 min each). Hypoglycemia was induced by insulin (Actrapid MC Novo, 0.1 IU/kg, i.v.). Oral administration of 50 g and 100 g of glucose was given to elevate plasma glucose. The activity of superoxide dismutase (SOD) was determined in red blood cells, whereas glutathione peroxidase (GSH-Px) activity was measured in whole blood. The concentration of malondialdehyde (MDA) was determined by HPLC, catecholamines were assessed radioenzymatically and glucose was measured by the glucose-oxidase method. Exercise increased MDA concentrations, GSH-Px and SOD activities as well as plasma noradrenaline and adrenaline levels. Insulin hypoglycemia increased plasma adrenaline levels, but the concentrations of MDA and the activities of GSH-Px and SOD were decreased. Hyperglycemia increased plasma MDA concentrations, but the activities of GSH-Px and SOD were significantly higher after a larger dose of glucose only. Plasma catecholamines were unchanged. These results indicate that the transient increase of plasma catecholamine and insulin concentrations did not induce oxidative damage, while glucose already in the low dose was an important triggering factor for oxidative stress.

  5. The role of dietary acid load and mild metabolic acidosis in insulin resistance in humans.

    Science.gov (United States)

    Williams, Rebecca S; Kozan, Pinar; Samocha-Bonet, Dorit

    2016-05-01

    Type 2 diabetes is increasingly being recognised as a global health crisis (World Health Organisation). Insulin resistance is closely associated with obesity and precedes the development of type 2 diabetes. However, there is now increasing evidence to suggest that diet itself may independently be associated with type 2 diabetes risk. A diet with a high acid load (or high potential renal net acid load, PRAL) can result in a decrease in pH towards the lower end of the normal physiological range, which may in turn lead to the development of insulin resistance. Conversely, reducing dietary acid load (the so called 'alkaline diet') may be protective and prevent the onset of type 2 diabetes. Here, we explore the influence of dietary acid load on the development of mild metabolic acidosis and induction of insulin resistance. Whilst large prospective cohort studies link high dietary acid load or low serum bicarbonate with the development of type 2 diabetes, the effect of a diet with a low acid (or high alkaline) load remains unclear. Further interventional studies are required to investigate the influence of dietary composition on the body's acid/base balance, insulin resistance and incidence of type 2 diabetes.

  6. Thylakoids promote release of the satiety hormone cholecystokinin while reducing insulin in healthy humans

    DEFF Research Database (Denmark)

    Köhnke, Rickard; Lindbo, Agnes; Larsson, Therese

    2009-01-01

    (CCK, leptin and ghrelin), insulin and blood metabolites (glucose and free fatty acids). RESULTS: The CCK level increased, in particular between the 120 min time-point and onwards, the ghrelin level was reduced at 120 min and leptin level increased at 360 min after intake of the thylakoid-enriched meal...

  7. Role of incretin hormones in the regulation of insulin secretion in diabetic and nondiabetic humans

    DEFF Research Database (Denmark)

    Holst, Jens Juul; Gromada, Jesper

    2004-01-01

    of GIP is near normal, whereas the secretion of GLP-1 is decreased. On the other hand, the insulintropic effect of GLP-1 is preserved, whereas the effect of GIP is greatly reduced, mainly because of a complete loss of the normal GIP-induced potentiation of second-phase insulin secretion. These two...

  8. Cx36 makes channels coupling human pancreatic beta-cells, and correlates with insulin expression

    NARCIS (Netherlands)

    Serre-Beinier, Veronique; Bosco, Domenico; Zulianello, Laurence; Charollais, Anne; Caille, Dorothee; Charpantier, Eric; Gauthier, Benoit R.; Diaferia, Giuseppe R.; Giepmans, Ben N.; Lupi, Roberto; Marchetti, Piero; Deng, Shaoping; Buhler, Leo; Berney, Thierry; Cirulli, Vincenzo; Meda, Paolo

    2009-01-01

    Previous studies have documented that the insulin-producing beta-cells of laboratory rodents are coupled by gap junction channels made solely of the connexin36 (Cx36) protein, and have shown that loss of this protein desynchronizes beta-cells, leading to secretory defects reminiscent of those observ

  9. Insulin-like growth factors and the multiplication of Tera-2, a human teratoma-derived cell line.

    Science.gov (United States)

    Biddle, C; Li, C H; Schofield, P N; Tate, V E; Hopkins, B; Engstrom, W; Huskisson, N S; Graham, C F

    1988-07-01

    A human teratoma cell line (Tera-2) was grown in serum-free medium, and the population multiplication was stimulated by the addition of somatomedins/insulin-like growth factors (IGFs). Both IGF-I and IGF-II gave maximal stimulation when added daily at 10 ng ml-1. The IGFs did not substantially change the labelling index of the cells, and the IGFs appeared to exert their effect on population multiplication by increasing cell survival. Membranes isolated from Tera-2 cells displayed both type 1 and type 2 IGF receptors.

  10. NMR structure of biosynthetic engineered human insulin monomer B31(Lys)-B32(Arg) in water/acetonitrile solution. Comparison with the solution structure of native human insulin monomer.

    Science.gov (United States)

    Bocian, Wojciech; Borowicz, Piotr; Mikołajczyk, Jerzy; Sitkowski, Jerzy; Tarnowska, Anna; Bednarek, Elzbieta; Głabski, Tadeusz; Tejchman-Małecka, Bozena; Bogiel, Monika; Kozerski, Lech

    2008-10-01

    A solution NMR-derived structure of a new long -acting, B31(Lys)-B32(Arg) (LysArg), engineered human insulin monomer, in H(2)O/CD(3)CN, 65/35 vol %, pH 3.6, is presented and compared with the available X-ray structure of a monomer that forms part of a hexamer (Smith, et al., Acta Crystallogr D 2003, 59, 474) and with NMR structure of human insulin in the same solvent (Bocian, et al., J Biomol NMR 2008, 40, 55-64). Detailed analysis using PFGSE NMR (Pulsed Field Gradient Spin Echo NMR) in dilution experiments and CSI analysis prove that the structure is monomeric in the concentration range 0.1-3 mM. The presence of long-range interstrand NOEs in a studied structure, relevant to the distances found in the crystal structure of the monomer, provides the evidence for conservation of the tertiary structure. Therefore the results suggest that this solvent system is a suitable medium for studying the native conformation of the protein, especially in situations (as found for insulins) in which extensive aggregation renders structure elucidations in water difficult or impossible. Starting from the structures calculated by the program CYANA, two different molecular dynamics (MD) simulated annealing refinement protocols were applied, either using the program AMBER in vacuum (AMBER_VC), or including a generalized Born solvent model (AMBER_GB). Here we present another independent evidence to the one presented recently by us (Bocian et al., J Biomol NMR 2008, 40, 55-64), that in water/acetonitrile solvent detailed structural and dynamic information can be obtained for important proteins that are naturally present as oligomers under native conditions.

  11. Unraveling the symmetry ambiguity in a hexamer: Calculation of the R6 human insulin structure

    Energy Technology Data Exchange (ETDEWEB)

    O' Donoghue, Sean I. [European Molecular Biology Laboratory (Germany); Chang Xiaoqing [University of Copenhagen, H.C. Orsted Institute, Department of Chemistry (Denmark); Abseher, Roger; Nilges, Michael [European Molecular Biology Laboratory (Germany); Led, Jens J. [University of Copenhagen, H.C. Orsted Institute, Department of Chemistry (Denmark)

    2000-02-15

    Crystallographic and NMR studies of insulin have revealed a highly flexible molecule with a range of different aggregation and structural states; the importance of these states for the function of the hormone is still unclear. To address this question, we have studied the solution structure of the insulin R{sub 6} symmetric hexamer using NMR spectroscopy. Structure determination of symmetric oligomers by NMR is complicated due to 'symmetry ambiguity' between intra- and intermonomer NOEs, and between different classes of intermonomer NOEs. Hence, to date, only two symmetric tetramers and one symmetric pentamer (VTB, B subunit of verotoxin) have been solved by NMR; there has been no other symmetric hexamer or higher-order oligomer. Recently, we reported a solution structure for R{sub 6} insulin hexamer. However, in that study, a crystal structure was used as a reference to resolve ambiguities caused by the threefold symmetry; the same method was used in solving VTB. Here, we have successfully recalculated R{sub 6} insulin using the symmetry-ADR method, a computational strategy in which ambiguities are resolved using the NMR data alone. Thus the obtained structure is a refinement of the previous R{sub 6} solution structure. Correlated motions in the final structural ensemble were analysed using a recently developed principal component method; this suggests the presence of two major conformational substates. The study demonstrates that the solution structure of higher-order symmetric oligomers can be determined unambiguously from NMR data alone, using the symmetry-ADR method. This success bodes well for future NMR studies of higher-order symmetric oligomers. The correlated motions observed in the structural ensemble suggest a new insight into the mechanism of phenol exchange and the T{sub 6} {r_reversible} R{sub 6} transition of insulin in solution.

  12. Liposomal insulin promoter-thymidine kinase gene therapy followed by ganciclovir effectively ablates human pancreatic cancer in mice.

    Science.gov (United States)

    Wu, James X; Liu, Shi-He; Nemunaitis, John J; Brunicardi, F Charles

    2015-04-10

    PDX1 is overexpressed in pancreatic cancer, and activates the insulin promoter (IP). Adenoviral IP-thymidine kinase and ganciclovir (TK/GCV) suppresses human pancreatic ductal carcinoma (PDAC) in mice, but repeated doses carry significant toxicity. We hypothesized that multiple cycles of liposomal IP-TK/GCV ablate human PDAC in SCID mice with minimal toxicity compared to adenoviral IP-TK/GCV. SCID mice with intraperitoneal human pancreatic cancer PANC-1 tumor implants were given a single cycle of 35 µg iv L-IP-TK, or four cycles of 1, 10, 20, 30, or 35 µg iv L-IP-TK (n = 20 per group), followed by intraperitoneal GCV. Insulin and glucose levels were monitored in mice treated with four cycles of 35 µg iv L-IP-TK. We found that four cycles of 10-35 µg L-IP-TK/GCV ablated more PANC-1 tumor volume compared to a single cycle with 35 µg. Mice that received four cycles of 10 µg L-IP-TK demonstrated the longest survival (P SCID mice with minimal toxicity, suggesting non-viral vectors are superior to adenoviral vectors for IP-gene therapy.

  13. Insulin aspart pharmacokinetics

    DEFF Research Database (Denmark)

    Rasmussen, Christian Hove; Roge, Rikke Meldgaard; Ma, Zhulin;

    2014-01-01

    Background: Insulin aspart (IAsp) is used by many diabetics as a meal-time insulin to control postprandial glucose levels. As is the case with many other insulin types, the pharmacokinetics (PK), and consequently the pharmacodynamics (PD), is associated with clinical variability, both between...... to investigate and quantify the properties of the subcutaneous depot. Data from Brange et al. (1990) are used to determine the effects of insulin chemistry in subcutis on the absorption rate. Intravenous (i.v.) bolus and infusion PK data for human insulin are used to understand and quantify the systemic...... distribution and elimination (Porksen et al., 1997; Sjostrand et al., 2002). PK and PD profiles for type 1 diabetics from Chen et al. (2005) are analyzed to demonstrate the effects of IAsp antibodies in terms of bound and unbound insulin. PK profiles from Thorisdottir et al. (2009) and Ma et al. (2012b...

  14. Type 1 Ig-E mediated allergy to human insulin, insulin analogues and beta-lactam antibiotics Hipersensibilidade imediata a insulina humana, análogos de insulina e a antibióticos beta-lactâmicos

    Directory of Open Access Journals (Sweden)

    Pedro Andrade

    2012-12-01

    Full Text Available Insulin, a crucial therapeutic agent for diabetes mellitus, has been rarely associated with hypersensitivity events. We present a 69-year-old type-2 diabetic patient with urticariform lesions on the sites of subcutaneous injection of insulin. The patient denied any known allergies, except for an unspecific cutaneous reaction after intramuscular penicillin administration in childhood. Prick tests revealed positive reactions to all tested human insulins and insulin analogues. Serum IgE levels were above normal range and RAST tests were positive for human, bovine and porcine insulins, as well as beta-lactams. Type 1 IgEmediated allergy to insulin analogues demands a prompt diagnosis and represents a significant therapeutic challenge in diabetic patients.A insulina é um agente indispensável para o controlo da diabetes mellitus. Os efeitos adversos da sua administração, em particular fenómenos de hipersensibilidade, são raros. Apresentamos um doente de 69 anos, diabético do tipo 2, com episódios recorrentes de lesões urticariformes nos locais de administração subcutânea de insulina. Negava alergias medicamentosas, à excepção de reacção não especificada na infância após penicilina intramuscular. Foram realizados testes cutâneos por puntura (prick tests com diversos tipos de insulina humana e análogos, todos com reacções positivas, associando elevação dos níveis de IgE sérica e provas RAST positivas para as insulinas humana, bovina e porcina e para os antibióticos beta-lactâmicos. A alergia a análogos de insulina exige um diagnóstico precoce, originando um desafio terapêutico importante no doente diabético.

  15. Zinc-α2-Glycoprotein Modulates AKT-Dependent Insulin Signaling in Human Adipocytes by Activation of the PP2A Phosphatase.

    Directory of Open Access Journals (Sweden)

    Victòria Ceperuelo-Mallafré

    Full Text Available Evidence from mouse models suggests that zinc-α2-glycoprotein (ZAG is a novel anti-obesity adipokine. In humans, however, data are controversial and its physiological role in adipose tissue (AT remains unknown. Here we explored the molecular mechanisms by which ZAG regulates carbohydrate metabolism in human adipocytes.ZAG action on glucose uptake and insulin action was analyzed. β1 and β2-adrenoreceptor (AR antagonists and siRNA targeting PP2A phosphatase were used to examine the mechanisms by which ZAG modulates insulin sensitivity. Plasma levels of ZAG were measured in a lean patient cohort stratified for HOMA-IR.ZAG treatment increased basal glucose uptake, correlating with an increase in GLUT expression, but induced insulin resistance in adipocytes. Pretreatment of adipocytes with propranolol and a specific β1-AR antagonist demonstrated that ZAG effects on basal glucose uptake and GLUT4 expression are mediated via β1-AR, whereas inhibition of insulin action is dependent on β2-AR activation. ZAG treatment correlated with an increase in PP2A activity. Silencing of the PP2A catalytic subunit abrogated the negative effect of ZAG on insulin-stimulated AKT phosphorylation and glucose uptake but not on GLUT4 expression and basal glucose uptake. ZAG circulating levels were unchanged in a lean patient cohort stratified for HOMA-IR. Neither glucose nor insulin was associated with plasma ZAG.ZAG inhibits insulin-induced glucose uptake in human adipocytes by impairing insulin signaling at the level of AKT in a β2-AR- and PP2A-dependent manner.

  16. Insulin pump therapy in pregnancy.

    Science.gov (United States)

    Kesavadev, Jothydev

    2016-09-01

    Control of blood glucose during pregnancy is difficult because of wide variations, ongoing hormonal changes and mood swings. The need for multiple injections, pain at the injection site, regular monitoring and skillful handling of the syringes/pen further makes insulin therapy inconvenient. Insulin pump is gaining popularity in pregnancy because it mimics the insulin delivery of a healthy human pancreas. Multiple guidelines have also recommended the use of insulin pump in pregnancy to maintain the glycaemic control. The pump can release small doses of insulin continuously (basal), or a bolus dose close to mealtime to control the spike in blood glucose after a meal and the newer devices can shut down insulin delivery before the occurrence of hypoglycaemia. Pump insulin of choice is rapid acting analogue insulin. This review underscores the role of insulin pump in pregnancy, their usage, advantages and disadvantages in the light of existing literature and clinic experience.

  17. Thermal dissociation and unfolding of insulin

    DEFF Research Database (Denmark)

    Huus, Kasper; Havelund, Svend; Olsen, Helle B;

    2005-01-01

    dimeric at room temperature, unfolded at approximately 70 degrees C. The two monomeric insulin mutants Asp(B28) and Asp(B9),Glu(B27) unfolded at higher temperatures, but with enthalpies of unfolding that were approximately 30% smaller. Small amounts of zinc caused a biphasic thermal denaturation pattern...... of insulin. The biphasic denaturation is caused by a redistribution of zinc ions during the heating process and results in two distinct transitions with T(m)'s of approximately 70 and approximately 87 degrees C corresponding to monomer/dimer and hexamer, respectively. At high zinc concentrations (>or=5 Zn(2...... denaturants where it has been shown that monomer unfolding takes place at much higher denaturant concentrations than the dissociation of higher oligomers [Ahmad, A., et al. (2004) J. Biol. Chem. 279, 14999-15013]....

  18. Potential Epigenetic Biomarkers of Obesity Related Insulin Resistance in Human Whole-blood.

    Science.gov (United States)

    Day, Samantha E; Coletta, Richard L; Kim, Joon Young; Garcia, Luis A; Campbell, Latoya E; Benjamin, Tonya R; Roust, Lori R; De Filippis, Elena A; Mandarino, Lawrence J; Coletta, Dawn K

    2017-01-20

    Obesity can increase the risk of complex metabolic diseases, including insulin resistance. Moreover, obesity can be caused by environmental and genetic factors. However, the epigenetic mechanisms of obesity are not well defined. Therefore, the identification of novel epigenetic biomarkers of obesity allows for a more complete understanding of the disease and its underlying insulin resistance. The aim of our study was to identify DNA methylation changes in whole-blood that were strongly associated with obesity and insulin resistance. Whole-blood was obtained from lean (n = 10; BMI = 23.6 ± 0.7 kg/m(2)) and obese (n = 10; BMI = 34.4 ± 1.3 kg/m(2)) participants in combination with euglycemic hyperinsulinemic clamps to assess insulin sensitivity. We performed reduced representation bisulfite sequencing on genomic DNA isolated from the blood. We identified 49 differentially methylated cytosines (DMCs; qobese compared to lean participants. We identified two sites (Chr.21:46,957,981 and Chr.21:46,957,915) in the 5' untranslated region of solute carrier family 19 member 1 (SLC19A1) with decreased in methylation in obese participants (lean 0.73 ± 0.11 vs. obese 0.09 ± 0.05; lean 0.68 ± 0.10 vs. obese 0.09 ± 0.05, respectively). These two DMCs identified by obesity were also significantly predicted by insulin sensitivity (r = 0.68, P = 0.003; r = 0.66; P = 0.004). In addition, we performed a differentially methylated region (DMR) analysis and demonstrated a decrease in methylation of Chr.21:46,957,915-46,958,001 in SLC19A1 of -34.9% (70.4% lean vs. 35.5% obese). The decrease in whole-blood SLC19A1 methylation in our obese participants was similar to the change observed in skeletal muscle (Chr.21:46,957,981, lean 0.70 ± 0.09 vs. obese 0.31 ± 0.11 and Chr.21:46,957,915, lean 0.72 ± 0.11 vs. obese 0.31 ± 0.13). Pyrosequencing analysis further demonstrated a decrease in methylation at Chr.21:46,957,915 in both whole-blood (lean 0.71 ± 0.10 vs. obese 0.18 ± 0

  19. Transgenic expression of human INS gene in Ins1/Ins2 double knockout mice leads to insulin underproduction and diabetes in some male mice.

    Science.gov (United States)

    Karaca, Melis; Durel, Béatrice; Languille, Laëtitia; Lamotte, Luciane; Tourrel-Cuzin, Cécile; Leroux, Loïc; Abou Sleymane, Gretta; Saint-Just, Susan; Bucchini, Danielle; Ktorza, Alain; Joshi, Rajiv L

    2007-01-01

    We have generated transgenic mouse lines expressing exclusively a human INS transgene on an Ins1/Ins2 double knockout (mIKO) background. The transgene expression was driven by either a 4000 bp or a 353 bp promoter. These transgenic lines, designated mIKO:INS4000 and mIKO:INS353, were viable and fertile. Determination of the amounts of insulin transcripts and total pancreatic insulin content revealed relative insulin underproduction in both lines, from birth to adulthood. Total pancreatic insulin stores in mIKO:INS4000 and mIKO:INS353 mice represented only about 50% and 27%, respectively, as compared to wild-type mice. Morphometric analysis of pancreas did not show any compensatory beta-cell hyperplasia. The majority of animals in both lines remained normoglycemic throughout their lives. Nevertheless, glucose tolerance tests revealed glucose intolerance in nearly half of mIKO:INS4000 male mice, likely due to impaired insulin secretion detected in those animals. In addition, a small fraction (2-4%) of male mice in both lines spontaneously developed diabetes with very distinct pathophysiological features. Diabetes was never seen in female animals. The diabetes developed by mIKO:INS353 mice was rapidly lethal, accompanied by a dramatic depletion of pancreatic insulin stores whereas the mIKO:INS4000 diabetic animals could live for several months. This suggests a possible link between the structure of the human INS gene promoter and the type of diabetes developed in these lines.

  20. Impact of the Xba1-polymorphism of the human muscle glycogen synthase gene on parameters of the insulin resistance syndrome in a Danish twin population

    DEFF Research Database (Denmark)

    Fenger, M; Poulsen, P; Beck-Nielsen, H;

    2000-01-01

    was increased in female carriers of the A2-allele with impaired glucose tolerance or Type 2 diabetes mellitus (79 +/- 1 vs. 94 +/- 4 mmHg, P insulin resistance syndrome were associated with the polymorphism. CONCLUSIONS......AIMS: To establish the impact on the insulin resistance syndrome of the intron 14 Xba1-polymorphism in human muscle glycogen synthase (GYS1). METHODS: Parameters related to the insulin resistance syndrome were measured in 244 monozygotic twins and 322 dizygotic twins with or without impaired...... and the remainder had the genotype A1A2. No A2A2-genotypes were detected. In 11 genotypic discordant dizygotic twin pairs the insulin resistance was significantly increased in the twins carrying the A1A2 genotype regardless of sex (HOMA index 1.81 (A1A1) vs. 2.57 (A1A2), P

  1. Effect of pulmonary surfactant and phospholipid hexadecanol tyloxapol on recombinant human-insulin absorption from intratracheally administered dry powders in diabetic rats.

    Science.gov (United States)

    Zheng, Jianheng; Zhang, Ge; Lu, Yang; Fang, Fang; He, Jiake; Li, Ning; Talbi, Amer; Zhang, Ying; Tang, Yue; Zhu, Jiabi; Chen, Xijing

    2010-12-01

    The purpose of the present study was to evaluate the enhancement effect of the natural pulmonary surfactant (PS) or its artificial substitute, phospholipid hexadecanol tyloxapol (PHT) on the bioavailability and hypoglycemic activity of recombinant human insulin (rh-insulin) in a pulmonary delivery system. PS- or PHT-loaded insulin formulation was administered to streptozotocin induced diabetic rats, at doses of 5 U/kg, 10 U/kg and 20 U/kg insulin, respectively. The hypoglycemic effect caused by PS or PHT containing rh-insulin was analyzed and the area above the curves (AAC) of serum glucose levels versus time, the minimum glucose concentration (C(min)), the time to C(min) (T(min)) and the pharmacological availability (PA%) were derived from the serum glucose profiles. Results showed that PS and PHT caused significantly decrease in serum glucose levels. The decrease in plasma glucose levels continued for about 5 h after the nadir. The highest AAC value was obtained when 20 U/kg rh-insulin with PS or PHT as absorption enhancer was administered to rats. AAC(0-360 min) of PS- or PHT-loaded rh-insulin was 2-3 times as much as that without PS or PHT and PA% increased by 1.3-2 fold. Thus, the extent of oral absorption of insulin from PS- or PHT-loaded particles was significantly greater when compared with that without them. In addition, PHT as well as PS did not change the lactate dehydrogenase (LDH) activity, alkaline phosphatase (AKP) activity and N-acetyl-β-D-glucoaminidase (NAG) activity in bronch fluid which are sensitive indicators of acute toxicity to lung cells in bronchoalveolar lavage (BAL). It is concluded that PS and PHT is a promising absorption enhancer for pulmonary delivery systems of large molecule drugs as rh-insulin.

  2. The influence of insulin on the raised plasma fibronectin concentration in human obesity

    DEFF Research Database (Denmark)

    Dejgård, A; Andersen, T; Gluud, C

    1986-01-01

    in the controls (obese r = 0.06, controls r = 0.02; p greater than 0.05). Plasma fibronectin was insignificantly correlated with body weight (obese r = 0.21, controls r = 0.15; p greater than 0.05) and percentage overweight (obese r = 0.27, controls r = 0.04; p greater than 0.05). The raised level of circulating...... insulin may in part explain the excess of plasma fibronectin obese subjects....

  3. Effects of glucose and insulin on secretion of amyloid‐β by human adipose tissue cells

    OpenAIRE

    2016-01-01

    Objective Obesity and type 2 diabetes mellitus are risk factors for developing Alzheimer disease. Overlapping patterns of metabolic dysfunction may be common molecular links between these complex diseases. Amyloid‐β (Aβ) precursor protein and associated β‐ and γ‐secretases are expressed in adipose tissue. Aβ precursor protein is up‐regulated with obesity and correlated to insulin resistance. Aβ may be secreted by adipose tissue, its production may be regulated through metabolic pathways, and ...

  4. Human adipose cells in vitro are either refractory or responsive to insulin, reflecting host metabolic state.

    Directory of Open Access Journals (Sweden)

    Vladimir A Lizunov

    Full Text Available While intercellular communication processes are frequently characterized by switch-like transitions, the endocrine system, including the adipose tissue response to insulin, has been characterized by graded responses. Yet here individual cells from adipose tissue biopsies are best described by a switch-like transition between the basal and insulin-stimulated states for the trafficking of the glucose transporter GLUT4. Two statistically-defined populations best describe the observed cellular heterogeneity, representing the fractions of refractive and responsive adipose cells. Furthermore, subjects exhibiting high systemic insulin sensitivity indices (SI have high fractions of responsive adipose cells in vitro, while subjects exhibiting decreasing SI have increasing fractions of refractory cells in vitro. Thus, a two-component model best describes the relationship between cellular refractory fraction and subject SI. Since isolated cells exhibit these different response characteristics in the presence of constant culture conditions and milieu, we suggest that a physiological switching mechanism at the adipose cellular level ultimately drives systemic SI.

  5. Action of a semi-synthetic human insulin preparation (30/70 NPH insulin Organon): comparison with another 30/70 NPH (Actraphane Novo).

    Science.gov (United States)

    Gin, H; Nivet, A M; Morlat, P; Aubertin, J

    1989-01-01

    The action of a new semi-synthetic insulin preparation (30% soluble, 70% NPH insulin from Organon Laboratories Eragny sur Epte France) was studied in 6 healthy male volunteers using the euglycemic clamp technique (Biostator GCIIS) and compared with another 30/70 NPH (Actraphane Novo). Insulin levels, inhibition of C peptide secretion and glucose consumption were determined. There was a time lag between the maximum glucose need (167 +/- 18 mg/Kg/15 min at the 195th minute after the injection) and the peak plasma insulin level (98.3 +/- 8.5 uu/ml at the 105th minute following the injection). The maximum glucose need was followed by a slow fall in insulin levels with a duration of action of 17 hours. The total glucose need was the same as for Actraphane, although Actraphane had a slower action with a lower peak glucose need (144 +/- 18 mg/Kg/15 min at the 280th minute after injection). The two preparations had the same duration of action.

  6. Blood-based biomarkers of age-associated epigenetic changes in human islets associate with insulin secretion and diabetes

    DEFF Research Database (Denmark)

    Bacos, Karl; Gillberg, Linn; Volkov, Petr;

    2016-01-01

    Aging associates with impaired pancreatic islet function and increased type 2 diabetes (T2D) risk. Here we examine whether age-related epigenetic changes affect human islet function and if blood-based epigenetic biomarkers reflect these changes and associate with future T2D. We analyse DNA...... methylation genome-wide in islets from 87 non-diabetic donors, aged 26-74 years. Aging associates with increased DNA methylation of 241 sites. These sites cover loci previously associated with T2D, for example, KLF14. Blood-based epigenetic biomarkers reflect age-related methylation changes in 83 genes...... demonstrate that blood-based epigenetic biomarkers reflect age-related DNA methylation changes in human islets, and associate with insulin secretion in vivo and T2D....

  7. Local administration of insulin-like growth factor-I (IGF-I) stimulates tendon collagen synthesis in humans

    DEFF Research Database (Denmark)

    Hansen, Mette; Boesen, A; Holm, L

    2012-01-01

    Collagen is the predominant structural protein in tendons and ligaments, and can be controlled by hormonal changes. In animals, injections of insulin-like growth factor I (IGF-I) has been shown to increase collagen synthesis in tendons and ligaments and to improve structural tissue healing......, but the effect of local IGF-I administration on tendon collagen synthesis in human has not been studied. The purpose of this study was to study whether local injections of IGF-I would have a stimulating effect on tendon collagen synthesis. Twelve healthy nonsmoking men [age 62 ± 1 years (mean ± SEM), BMI 27 ± 1......] participated. Two injections of either human recombinant IGF-I (0.1 mL Increlex©) or saline (control) into each patellar tendon were performed 24-h apart, respectively. Tendon collagen fractional synthesis rate (FSR) was measured by stable isotope technique in the hours after the second injection...

  8. [Expression of human insulin in lactic acid bacteria and its oral administration in non-obese diabetic mice].

    Science.gov (United States)

    Chen, Si-Wei; Zhong, Jin; Huan, Lian-Dong

    2007-12-01

    Type 1 diabetes mellitus (T1DM) is an auto-immune disease while oral administrating its autoantigens could be a treatment of T1DM. To express human insulin gene (ins) in lactic acid bacteria (LAB) for oral vaccine, ins gene was replaced by LAB bias codon and an 8-amino-acid-residue linker peptide forming a beta-turn was designed to link insulin chain A and B. After synthesized by primer annealing method, the whole ins gene was fused with signal peptide sequence SP(Usp45), subcloned into a LAB secretory expressive vector pSW501 and then introduced to Lactococcus lactis (L. lactis) MG1363 and Lactobacillus casei (Lb. casei ) ATCC27092 respectively. Western blot showed that the expression product (SP(Usp45)-INS protein) targeted mainly at the cell wall while little was found in cytoplasm or supernatant. The highest expression level emerged in exponential phase when the optical density at 600nm of the culture was 0.4. The culture of the recombinant strain Lb. casei/pSW501 was administered to non-obese diabetic (NOD) mice orally. ELISA and Western blot results showed that the recombinant strain could induce SP(Usp45)-INS-specific antibodies and raise IL-4 level (38.583 +/- 2.083 pg/mL, P < 0.05) in the mice' s sera. Expression of insulin in the food-grade vehicle LAB could induce oral immune tolerance in NOD mice and protect it from pancreas injury, suggesting it might be a new way to the treatment of T1DM.

  9. Modeling Biphasic Environmental Decay of Pathogens and Implications for Risk Analysis.

    Science.gov (United States)

    Brouwer, Andrew F; Eisenberg, Marisa C; Remais, Justin V; Collender, Philip A; Meza, Rafael; Eisenberg, Joseph N S

    2017-02-21

    As the appreciation for the importance of the environment in infectious disease transmission has grown, so too has interest in pathogen fate and transport. Fate has been traditionally described by simple exponential decay, but there is increasing recognition that some pathogens demonstrate a biphasic pattern of decay-fast followed by slow. While many have attributed this behavior to population heterogeneity, we demonstrate that biphasic dynamics can arise through a number of plausible mechanisms. We examine the identifiability of a general model encompassing three such mechanisms: population heterogeneity, hardening off, and the existence of viable-but-not-culturable states. Although the models are not fully identifiable from longitudinal sampling studies of pathogen concentrations, we use a differential algebra approach to determine identifiable parameter combinations. Through case studies using Cryptosporidium and Escherichia coli, we show that failure to consider biphasic pathogen dynamics can lead to substantial under- or overestimation of disease risks and pathogen concentrations, depending on the context. More reliable models for environmental hazards and human health risks are possible with an improved understanding of the conditions in which biphasic die-off is expected. Understanding the mechanisms of pathogen decay will ultimately enhance our control efforts to mitigate exposure to environmental contamination.

  10. Zinc Up-Regulates Insulin Secretion from β Cell-Like Cells Derived from Stem Cells from Human Exfoliated Deciduous Tooth (SHED)

    Science.gov (United States)

    Kim, Gyuyoup; Shin, Ki-Hyuk; Pae, Eung-Kwon

    2016-01-01

    Stem cells from human exfoliated deciduous tooth (SHED) offer several advantages over other stem cell sources. Using SHED, we examined the roles of zinc and the zinc uptake transporter ZIP8 (Zrt- and irt-like protein 8) while inducing SHED into insulin secreting β cell-like stem cells (i.e., SHED-β cells). We observed that ZIP8 expression increased as SHED differentiated into SHED-β cells, and that zinc supplementation at day 10 increased the levels of most pancreatic β cell markers—particularly Insulin and glucose transporter 2 (GLUT2). We confirmed that SHED-β cells produce insulin successfully. In addition, we note that zinc supplementation significantly increases insulin secretion with a significant elevation of ZIP8 transporters in SHED-β cells. We conclude that SHED can be converted into insulin-secreting β cell-like cells as zinc concentration in the cytosol is elevated. Insulin production by SHED-β cells can be regulated via modulation of zinc concentration in the media as ZIP8 expression in the SHED-β cells increases. PMID:27983594

  11. Zinc Up-Regulates Insulin Secretion from β Cell-Like Cells Derived from Stem Cells from Human Exfoliated Deciduous Tooth (SHED

    Directory of Open Access Journals (Sweden)

    Gyuyoup Kim

    2016-12-01

    Full Text Available Stem cells from human exfoliated deciduous tooth (SHED offer several advantages over other stem cell sources. Using SHED, we examined the roles of zinc and the zinc uptake transporter ZIP8 (Zrt- and irt-like protein 8 while inducing SHED into insulin secreting β cell-like stem cells (i.e., SHED-β cells. We observed that ZIP8 expression increased as SHED differentiated into SHED-β cells, and that zinc supplementation at day 10 increased the levels of most pancreatic β cell markers—particularly Insulin and glucose transporter 2 (GLUT2. We confirmed that SHED-β cells produce insulin successfully. In addition, we note that zinc supplementation significantly increases insulin secretion with a significant elevation of ZIP8 transporters in SHED-β cells. We conclude that SHED can be converted into insulin-secreting β cell-like cells as zinc concentration in the cytosol is elevated. Insulin production by SHED-β cells can be regulated via modulation of zinc concentration in the media as ZIP8 expression in the SHED-β cells increases.

  12. Paternally transmitted IDDM2 influences diabetes susceptibility despite biallelic expression of the insulin gene in human pancreas.

    Science.gov (United States)

    Bui, M M; Luo, D F; She, J Y; Maclaren, N K; Muir, A; Thomson, G; She, J X

    1996-02-01

    Whereas it is well known that the insulin gene (INS) region at 11p15.5 (IDDM2) confers susceptibility to insulin-dependent diabetes mellitus (IDDM), it is still controversial whether the parental origin of IDDM2 influences IDDM susceptibility. We have analysed the Pst I + 1127 polymorphism in 123 USA multiplex families and detected linkage only in male meioses using the affected sibpair analysis (P = 0.009). Application of the transmission/disequilibrium test (TDT) found significantly increased transmission of the IDDM-associated INS allele from fathers heterozygous for INS to their diabetic offspring (P = 0.00002), but the transmission from heterozygous mothers was not significantly different from random expectation. In non-diabetic families, the transmission from parents heterozygous for INS was not significantly different from random expectation in either paternal or maternal meioses. Maternal imprinting of the INS gene in pancreatic islets was originally considered the most favorable explanation for the observed gender-related difference. However, our study has demonstrated biallelic expression of INS in pancreatic tissues from the human fetuses and thus suggests that INS is probably not imprinted in the pancreatic islets.

  13. In-vitro evaluation of the effect of polymer structure on uptake of novel polymer-insulin polyelectrolyte complexes by human epithelial cells.

    Science.gov (United States)

    Ibie, C; Knott, R; Thompson, C J

    2015-02-01

    The biocompatibility and cellular uptake of polymer, insulin polyelectrolyte complexes (PECs) prepared using polyallylamine-based polymers was evaluated in-vitro using Caco-2 cell monolayers as a predictive model for human small intestinal epithelial cells. Poly(allyl amine) (PAA) and Quaternised PAA (QPAA) were thiolated using either carbodiimide mediated conjugation to N-acetylcysteine (NAC) or reaction with 2-iminothiolane hydrochloride yielding their NAC and 4-thiobutylamidine (TBA) conjugates, respectively. The effect of polymer quaternisation and/or thiolation on the IC50 of PAA was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay carried out on Caco-2 cells (with and without a 24 h recovery period after samples were removed). Uptake of PECs by Caco-2 cells was monitored by microscopy using fluorescein isothiocyanate (FITC) labelled insulin and rhodamine-labelled polymers at polymer:insulin ratios (4:5) after 0.5, 1, 2 and 4 h incubation in growth media (±calcium) and following pre-incubation with insulin. MTT results indicated that quaternisation of PAA was associated with an improvement in IC50 values; cells treated with QPAA (0.001-4 mg mL(-1)) showed no signs of toxicity following a 24 h cell recovery period, while thiolation of QPAA resulted in a decrease in the IC50. Cellular uptake studies showed that within 2-4 h, QPAA and QPAA-TBA insulin PECs were taken up intracellularly, with PECs being localised within the perinuclear area of cells. Further investigation showed that uptake of PECs was unaffected when calcium-free media was used, while presaturating insulin receptors affected the uptake of QPAA, insulin PECs, but not QPAA-TBA PECs. The biocompatibility of PAA and uptake of insulin was improved by both thiol and quaternary substitution.

  14. Induction of human umbilical cord blood-derived stem cells with embryonic stem cell phenotypes into insulin producing islet-like structure.

    Science.gov (United States)

    Sun, Bo; Roh, Kyung-Hwan; Lee, Sae-Rom; Lee, Yong-Soon; Kang, Kyung-Sun

    2007-03-23

    Success in islet-transplantation-based therapies for type I diabetes, coupled with a worldwide shortage of transplant-ready islets, has motivated efforts to develop renewable sources of islet-replacement tissue. Embryonic stem cells (ESCs) have been successfully induced into insulin producing islet-like structure in several studies. However, the source of the ESCs has presented ethical and technical concerns. Here, we isolated a population of stem cells from human cord blood (UCB), which expressed embryo stage specific maker, SSEA-4, and the multi-potential stem cell marker, Oct4. Subsequently, we successfully induced them into insulin-producing islet-like structures, which co-express insulin and C-peptide. These findings might have a significant potential to advance human UCB derived stem-cell-based therapeutics for diabetes.

  15. Dissociation of GLP-1 and insulin association with food processing in the brain: GLP-1 sensitivity despite insulin resistance in obese humans

    Directory of Open Access Journals (Sweden)

    Martin Heni

    2015-12-01

    Conclusions: The postprandial release of GLP-1 might alter reward processes in the orbitofrontal cortex and might thereby support the termination of food intake and reduce hunger. While obese persons showed brain insulin resistance, no GLP-1 resistance was observed. Our study provides novel insight into the central regulation of food intake by the incretin hormone GLP-1.

  16. Coordinated Defects in Hepatic Long Chain Fatty Acid Metabolism and Triglyceride Accumulation Contribute to Insulin Resistance in Non-Human Primates

    Science.gov (United States)

    Gastaldelli, Amalia; Casiraghi, Francesca; Halff, Glenn A.; Abrahamian, Gregory A.; Davalli, Alberto M.; Bastarrachea, Raul A.; Comuzzie, Anthony G.; Guardado-Mendoza, Rodolfo; Jimenez-Ceja, Lilia M.; Mattern, Vicki; Paez, Ana Maria; Ricotti, Andrea; Tejero, Mary E.; Higgins, Paul B.; Rodriguez-Sanchez, Iram Pablo; Tripathy, Devjit; DeFronzo, Ralph A.; Dick, Edward J.; Cline, Gary W.; Folli, Franco

    2011-01-01

    Non-Alcoholic fatty liver disease (NAFLD) is characterized by accumulation of triglycerides (TG) in hepatocytes, which may also trigger cirrhosis. The mechanisms of NAFLD are not fully understood, but insulin resistance has been proposed as a key determinant. Aims To determine the TG content and long chain fatty acyl CoA composition profile in liver from obese non-diabetic insulin resistant (IR) and lean insulin sensitive (IS) baboons in relation with hepatic and peripheral insulin sensitivity. Methods Twenty baboons with varying grades of adiposity were studied. Hepatic (liver) and peripheral (mainly muscle) insulin sensitivity was measured with a euglycemic clamp and QUICKI. Liver biopsies were performed at baseline for TG content and LCFA profile by mass spectrometry, and histological analysis. Findings were correlated with clinical and biochemical markers of adiposity and insulin resistance. Results Obese IR baboons had elevated liver TG content compared to IS. Furthermore, the concentration of unsaturated (LC-UFA) was greater than saturated (LC-SFA) fatty acyl CoA in the liver. Interestingly, LC-FA UFA and SFA correlated with waist, BMI, insulin, NEFA, TG, QUICKI, but not M/I. Histological findings of NAFLD ranging from focal to diffuse hepatic steatosis were found in obese IR baboons. Conclusion Liver TG content is closely related with both hepatic and peripheral IR, whereas liver LC-UFA and LC-SFA are closely related only with hepatic IR in non-human primates. Mechanisms leading to the accumulation of TG, LC-UFA and an altered UFA: LC-SFA ratio may play an important role in the pathophysiology of fatty liver disease in humans. PMID:22125617

  17. Coordinated defects in hepatic long chain fatty acid metabolism and triglyceride accumulation contribute to insulin resistance in non-human primates.

    Directory of Open Access Journals (Sweden)

    Subhash Kamath

    Full Text Available Non-alcoholic fatty liver disease (NAFLD is characterized by accumulation of triglycerides (TG in hepatocytes, which may also trigger cirrhosis. The mechanisms of NAFLD are not fully understood, but insulin resistance has been proposed as a key determinant.To determine the TG content and long chain fatty acyl CoA composition profile in liver from obese non-diabetic insulin resistant (IR and lean insulin sensitive (IS baboons in relation with hepatic and peripheral insulin sensitivity.Twenty baboons with varying grades of adiposity were studied. Hepatic (liver and peripheral (mainly muscle insulin sensitivity was measured with a euglycemic clamp and QUICKI. Liver biopsies were performed at baseline for TG content and LCFA profile by mass spectrometry, and histological analysis. Findings were correlated with clinical and biochemical markers of adiposity and insulin resistance.Obese IR baboons had elevated liver TG content compared to IS. Furthermore, the concentration of unsaturated (LC-UFA was greater than saturated (LC-SFA fatty acyl CoA in the liver. Interestingly, LC-FA UFA and SFA correlated with waist, BMI, insulin, NEFA, TG, QUICKI, but not M/I. Histological findings of NAFLD ranging from focal to diffuse hepatic steatosis were found in obese IR baboons.Liver TG content is closely related with both hepatic and peripheral IR, whereas liver LC-UFA and LC-SFA are closely related only with hepatic IR in non-human primates. Mechanisms leading to the accumulation of TG, LC-UFA and an altered UFA: LC-SFA ratio may play an important role in the pathophysiology of fatty liver disease in humans.

  18. Effects of acute pinitol supplementation on plasma pinitol concentration, whole body glucose tolerance, and activation of the skeletal muscle insulin receptor in older humans.

    Science.gov (United States)

    Stull, A J; Wood, K V; Thyfault, J P; Campbell, W W

    2009-05-01

    Limited research with rodents and humans suggests that oral ingestion of pinitol (3- O-methyl- D- CHIRO-inositol) might positively influence glucose tolerance. This double-blinded, placebo-controlled, and cross-over study assessed the effects of acute pinitol supplementation on plasma pinitol concentration, glucose tolerance, insulin sensitivity, and activation of the skeletal muscle insulin receptor. Fifteen older, nondiabetic subjects (62+/-1 years, mean+/-SEM) completed four, 1-day trials. Subjects consumed a non-nutritive beverage with nothing (placebo) or 1,000 mg pinitol. Sixty minutes later, the subjects consumed beverages that were either energy- and carbohydrate-free (Sham) or contained 75 g glucose (OGTT). Blood samples were collected frequently over the 240-min testing period. For the OGTT trials only, vastus lateralis samples were obtained before the placebo and pinitol supplementation and 60 min after consuming the 75 g glucose beverage. Plasma pinitol concentration increased and was maintained for 240 min. Pinitol did not influence the fasting state and 180-min area under the curves for plasma glucose and insulin during the Sham and OGTT trials or hepatic (placebo 0.83+/-0.08; pinitol 0.80+/-0.08) and whole-body (placebo 6.10+/-0.54; pinitol 6.22+/-0.52) insulin sensitivities. Activation of the muscle insulin receptor was increased by 140% with glucose ingestion (Pre 0.62+/-0.12; Post 1.49+/-0.35), but pinitol did not influence this response. These results show that the pinitol supplement was quickly absorbed, but did not acutely influence indices of whole-body glucose tolerance and insulin sensitivity, or the activation of the skeletal muscle insulin receptor in older, nondiabetic humans.

  19. Application of PK/PD modeling and simulation to dosing regimen optimization of high-dose human regular U-500 insulin.

    Science.gov (United States)

    de la Peña, Amparo; Ma, Xiaosu; Reddy, Shobha; Ovalle, Fernando; Bergenstal, Richard M; Jackson, Jeffrey A

    2014-07-01

    Pharmacokinetic/pharmacodynamic (PK/PD) studies of human regular U-500 insulin (U-500R) at high doses commonly used in clinical practice (>100 units) have not been performed. The current analysis applied PK/PD modeling/simulation to fit the data and simulate single-dose and steady-state PK/PD of U-500R high-dose regimens. Data from 3 single-dose euglycemic clamp studies in healthy obese and normal-weight patients, and normal-weight patients with type 1 diabetes were used to build the model. The model was sequential (PK inputs fed into PD component). PK was described using a 1-compartment model with first-order absorption and elimination. The model estimated separate absorption rate constants for U-500R and human regular U-100 insulin. The PD component used an effect compartment model, parameterized in terms of maximum pharmacologic effect (E(max)) and concentration to achieve 50% of E(max). The model described the data well. Steady-state PK for once-daily (QD), twice-daily (BID), or thrice-daily (TID) administration appeared to be reached 24 hours after the first dose. At steady-state, QD dosing showed the greatest fluctuations in PK/PD. BID dosing showed a gradual increase in insulin action with each dose and a fairly stable basal insulin effect. For TID dosing, activity was maintained throughout the dosing interval. PK/PD modeling/simulation of high U-500R doses supports BID or TID administration with an extended duration of activity relative to QD. TID dosing may provide slightly better full-day insulin effect. Additional PK/PD studies and randomized controlled trials of U-500R are needed to validate model predictions in patients with insulin-resistant diabetes requiring high-dose insulin.

  20. 胰岛素泵联合人胰岛素在妊娠糖尿病治疗中的应用及护理%Application and Nursing Experience of Insulin Pump Combined with Human Insulin for Gestational Diabetes Mellitus

    Institute of Scientific and Technical Information of China (English)

    董淑芬; 姜廷辉; 那昕; 冯瑞平; 赵艳荣

    2011-01-01

    目的 探讨胰岛素泵联合人胰岛素治疗妊娠糖尿病的临床疗效及护理经验。方法 选择昌黎县人民医院62例妊娠糖尿病患者,在进行糖尿病健康教育、饮食和运动指导、监测血糖的基础上,随机分为胰岛素泵组(32例)和对照组(30例)。胰岛素泵组使用胰岛素泵持续皮下输注人胰岛素(诺和灵R),并加强用泵护理;对照组应用人胰岛素(诺和灵30R)早、晚餐前30 min皮下注射。观察2组患者治疗后血糖控制情况、血糖达标时间、每日胰岛素用量、低血糖发生率和孕产妇、围生儿死亡率。结果 2组患者治疗后空腹血糖(FBG)及平均三餐后2 h血糖(2 hBG)均较治疗前明显降低,且胰岛素泵组较对照组降低更明显,差异有统计学意义(P<0.01);胰岛素泵组较对照组在血糖达标时间、每日胰岛素用量上差异有统计学意义(P<0.01);胰岛素泵组低血糖发生率、孕产妇和围生儿死亡率较对照组降低。结论 用胰岛素泵联合人胰岛素治疗妊娠糖尿病,可使患者血糖控制稳定,增加母婴安全系数。%[Objective] To investigate the therapeutic effect and nursing experience of insulin pump combined with human insulin for gestational diabetes meUitus. [Methods]62 patients with gestational diabetes mellitus in Changli Peopled Hospital were randomly divided into the insulin pump group (32 cases) and the control group ( 30 cases). All of patients were given health education of diabetes mellitus, guidance for dietary and exercise, and monitoring of blood glucose. The insulin pump group was treated with continuous subcutaneous human insulin ( Novolin R) injection by insulin pump, and the nursing for insulin pump was strengthened. The control group was treated with human insulin (Novolin 30R) hypodermic injection 30 min before breakfast and dinner. After the treatment, blood glucose, time of reaching normal glucose, daily insulin dosage, the incidence

  1. Insulin Injection

    Science.gov (United States)

    ... or buttocks. Do not inject insulin into muscles, scars, or moles. Use a different site for each ... you are using insulin.Alcohol may cause a decrease in blood sugar. Ask your doctor about the ...

  2. Quantitative variation in obesity-related traits and insulin precursors linked to the OB gene region on human chromosome 7

    Energy Technology Data Exchange (ETDEWEB)

    Duggirala, R.; Stern, M.P.; Reinhart, L.J. [Univ. of Texas Health Science Center, San Antonio, TX (United States)] [and others

    1996-09-01

    Despite the evidence that human obesity has strong genetic determinants, efforts at identifying specific genes that influence human obesity have largely been unsuccessful. Using the sibship data obtained from 32 low-income Mexican American pedigrees ascertained on a type II diabetic proband and a multipoint variance-components method, we tested for linkage between various obesity-related traits plus associated metabolic traits and 15 markers on human chromosome 7. We found evidence for linkage between markers in the OB gene region and various traits, as follows: D7S514 and extremity skinfolds (LOD = 3.1), human carboxypeptidase A1 (HCPA1) and 32,33-split proinsulin level (LOD = 4.2), and HCPA1 and proinsulin level (LOD = 3.2). A putative susceptibility locus linked to the marker D7S514 explained 56% of the total phenotypic variation in extremity skinfolds. Variation at the HCPA1 locus explained 64% of phenotypic variation in proinsulin level and {approximately}73% of phenotypic variation in split proinsulin concentration, respectively. Weaker evidence for linkage to several other obesity-related traits (e.g., waist circumference, body-mass index, fat mass by bioimpedance, etc.) was observed for a genetic location, which is {approximately}15 cM telomeric to OB. In conclusion, our study reveals that the OB region plays a significant role in determining the phenotypic variation of both insulin precursors and obesity-related traits, at least in Mexican Americans. 66 refs., 3 figs., 4 tabs.

  3. AQUEOUS BIPHASE EXTRACTION FOR PROCESSING OF FINE COAL

    Energy Technology Data Exchange (ETDEWEB)

    K. Osseo-Asare; X. Zeng

    2002-01-01

    The objective of this research project is to develop an aqueous biphase extraction process for the treatment of fine coals. Aqueous biphase extraction is an advanced separation technology that relies on the ability of an aqueous system consisting of a water-soluble polymer and another component, e.g., another polymer, an inorganic salt, or a nonionic surfactant, to separate into two immiscible aqueous phases. The principle behind the partition of solid particles in aqueous biphase systems is the physicochemical interaction between the solid surface and the surrounding liquid solution. In order to remove sulfur and mineral matter from fine coal with aqueous biphasic extraction, it is necessary to know the partitioning behavior of coal, as well as the inorganic mineral components. Therefore, in this research emphasis was placed on the partitioning behavior of fine coal particles as well as model fine inorganic particles in aqueous biphase systems.

  4. Human insulin analogues modified at the B26 site reveal a hormone conformation that is undetected in the receptor complex

    Energy Technology Data Exchange (ETDEWEB)

    Žáková, Lenka; Kletvíková, Emília; Lepšík, Martin; Collinsová, Michaela [Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10 Prague 6 (Czech Republic); Watson, Christopher J.; Turkenburg, Johan P. [The University of York, Heslington, York YO10 5DD (United Kingdom); Jiráček, Jiří [Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10 Prague 6 (Czech Republic); Brzozowski, Andrzej M., E-mail: marek.brzozowski@york.ac.uk [The University of York, Heslington, York YO10 5DD (United Kingdom); Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10 Prague 6 (Czech Republic)

    2014-10-01

    [AsnB26]- and [GlyB26]-insulin mutants attain a B26-turn like fold without assistance of chemical modifications. Their structures match the insulin receptor interface and expand the spectrum of insulin conformations. The structural characterization of the insulin–insulin receptor (IR) interaction still lacks the conformation of the crucial B21–B30 insulin region, which must be different from that in its storage forms to ensure effective receptor binding. Here, it is shown that insulin analogues modified by natural amino acids at the TyrB26 site can represent an active form of this hormone. In particular, [AsnB26]-insulin and [GlyB26]-insulin attain a B26-turn-like conformation that differs from that in all known structures of the native hormone. It also matches the receptor interface, avoiding substantial steric clashes. This indicates that insulin may attain a B26-turn-like conformation upon IR binding. Moreover, there is an unexpected, but significant, binding specificity of the AsnB26 mutant for predominantly the metabolic B isoform of the receptor. As it is correlated with the B26 bend of the B-chain of the hormone, the structures of AsnB26 analogues may provide the first structural insight into the structural origins of differential insulin signalling through insulin receptor A and B isoforms.

  5. Tumor necrosis factor-alpha inhibits insulin's stimulating effect on glucose uptake and endothelium-dependent vasodilation in humans

    DEFF Research Database (Denmark)

    Rask-Madsen, Christian; Domínguez, Helena; Ihlemann, Nikolaj

    2003-01-01

    -alpha was smaller (PTNF-alpha had no effect on the SNP response without insulin infusion. Thus, TNF-alpha inhibition of the combined response to insulin and ACh was likely mediated through inhibition of NO production. CONCLUSIONS: These results support the concept that TNF-alpha could play a role......BACKGROUND: Inflammatory mechanisms could be involved in the pathogenesis of both insulin resistance and atherosclerosis. Therefore, we aimed at examining whether the proinflammatory cytokine tumor necrosis factor (TNF)-alpha inhibits insulin-stimulated glucose uptake and insulin....../or TNF-alpha were coinfused. During infusion of insulin alone for 20 minutes, forearm glucose uptake increased by 220+/-44%. This increase was completely inhibited during coinfusion of TNF-alpha (started 10 min before insulin) with a more pronounced inhibition of glucose extraction than of blood flow...

  6. Inhibition of insulin amyloid fibril formation by cyclodextrins.

    Science.gov (United States)

    Kitagawa, Keisuke; Misumi, Yohei; Ueda, Mitsuharu; Hayashi, Yuya; Tasaki, Masayoshi; Obayashi, Konen; Yamashita, Taro; Jono, Hirofumi; Arima, Hidetoshi; Ando, Yukio

    2015-01-01

    Localized insulin-derived amyloid masses occasionally form at the site of repeated insulin injections in patients with insulin-dependent diabetes and cause subcutaneous insulin resistance. Various kinds of insulin including porcine insulin, human insulin, and insulin analogues reportedly formed amyloid fibrils in vitro and in vivo, but the impact of the amino acid replacement in insulin molecules on amyloidogenicity is largely unknown. In the present study, we demonstrated the difference in amyloid fibril formation kinetics of human insulin and insulin analogues, which suggests an important role of the C-terminal domain of the insulin B chain in nuclear formation of amyloid fibrils. Furthermore, we determined that cyclodextrins, which are widely used as drug carriers in the pharmaceutical field, had an inhibitory effect on the nuclear formation of insulin amyloid fibrils. These findings have significant implications for the mechanism underlying insulin amyloid fibril formation and for developing optimal additives to prevent this subcutaneous adverse effect.

  7. Conformational states and recognition of amyloidogenic peptides of human insulin-degrading enzyme.

    Science.gov (United States)

    McCord, Lauren A; Liang, Wenguang G; Dowdell, Evan; Kalas, Vasilios; Hoey, Robert J; Koide, Akiko; Koide, Shohei; Tang, Wei-Jen

    2013-08-20

    Insulin-degrading enzyme (IDE) selectively degrades the monomer of amyloidogenic peptides and contributes to clearance of amyloid β (Aβ). Thus, IDE retards the progression of Alzheimer's disease. IDE possesses an enclosed catalytic chamber that engulfs and degrades its peptide substrates; however, the molecular mechanism of IDE function, including substrate access to the chamber and recognition, remains elusive. Here, we captured a unique IDE conformation by using a synthetic antibody fragment as a crystallization chaperone. An unexpected displacement of a door subdomain creates an ~18-Å opening to the chamber. This swinging-door mechanism permits the entry of short peptides into the catalytic chamber and disrupts the catalytic site within IDE door subdomain. Given the propensity of amyloidogenic peptides to convert into β-strands for their polymerization into amyloid fibrils, they also use such β-strands to stabilize the disrupted catalytic site resided at IDE door subdomain for their degradation by IDE. Thus, action of the swinging door allows IDE to recognize amyloidogenicity by substrate-induced stabilization of the IDE catalytic cleft. Small angle X-ray scattering (SAXS) analysis revealed that IDE exists as a mixture of closed and open states. These open states, which are distinct from the swinging door state, permit entry of larger substrates (e.g., Aβ, insulin) to the chamber and are preferred in solution. Mutational studies confirmed the critical roles of the door subdomain and hinge loop joining the N- and C-terminal halves of IDE for catalysis. Together, our data provide insights into the conformational changes of IDE that govern the selective destruction of amyloidogenic peptides.

  8. Human placental growth hormone, insulin-like growth factor I and -II, and insulin requirements during pregnancy in type 1 diabetes

    DEFF Research Database (Denmark)

    Fuglsang, Jens; Lauszus, Finn; Flyvbjerg, Allan

    2003-01-01

    influence of hPGH on placental weight was found. Serum IGF-I values decreased significantly from the first to the second trimester (P changes in IGF-I followed the increase in hPGH between wk 26-35 (r(s) = 0.53; P ...-II (r(s) = 0.37; P = 0.008). Changes in IGF-I and IGF-II between wk 26-35 also correlated to the birth weight z-score (P ...PGH was not correlated to the increase in insulin requirements, nor was any consistent relationship revealed during each gestational period. In conclusion, our study suggests a role for hPGH in the regulation of both IGFs and fetal growth in type 1 diabetes. In contrast, the increase in insulin requirements during...

  9. A Branched-Chain Amino Acid-Related Metabolic Signature that Differentiates Obese and Lean Humans and Contributes to Insulin Resistance

    OpenAIRE

    Newgard, Christopher B.; An, Jie; Bain, James R.; Muehlbauer, Michael J.; Robert D. Stevens; Lien, Lillian F.; Haqq, Andrea M.; Shah, Svati H.; Arlotto, Michelle; Slentz, Cris A.; Rochon, James; Gallup, Dianne; Ilkayeva, Olga; Brett R. Wenner; Yancy, William E

    2009-01-01

    Metabolomic profiling of obese versus lean humans reveals a branched-chain amino acid (BCAA)-related metabolite signature that is suggestive of increased catabolism of BCAA and correlated with insulin resistance. To test its impact on metabolic homeostasis, we fed rats on high-fat (HF), HF with supplemented BCAA (HF/BCAA) or standard chow (SC) diets. Despite having reduced food intake and weight gain equivalent to the SC group, HF/BCAA rats were equally insulin resistant as HF rats. Pair-feed...

  10. 4-Hydroxy-2-nonenal induces endothelial cell injury via PKCdelta and biphasic JNK activation

    OpenAIRE

    Goya, Sho; Hirata, Haruhiko; Hoshino, Shigenori; Inoue, Koji; Kashiwa, Yozo; Kawase, Ichiro; Kijima, Takashi; Kumagai, Toru; Mayumi, Masahiko; Osaki, Tadashi; Suzuki, Mayumi; Tachibana, Isao; Takeda, Yoshito; Takimoto, Takayuki; Yano, Yukihiro

    2008-01-01

    4-Hydroxy-2-nonenal (4-HNE), a major product generated during oxidative stress, exhibits cytotoxic effects; however, the mechanisms of 4-HNE-induced endothelial cell injury are not well defined. To explore this issue, we examined how 4-HNE damages human umbilical vein endothelial cells (HUVECs) and found that 4-HNE induced biphasic activation of c-Jun N-terminal kinase (JNK). Both pre- and post-treatment of HUVECs with SP600125, a specific JNK inhibitor, significantly suppresse...

  11. Protein phosphatase 1 (PP-1)-dependent inhibition of insulin secretion by leptin in INS-1 pancreatic β-cells and human pancreatic islets.

    Science.gov (United States)

    Kuehnen, Peter; Laubner, Katharina; Raile, Klemens; Schöfl, Christof; Jakob, Franz; Pilz, Ingo; Päth, Günter; Seufert, Jochen

    2011-05-01

    Leptin inhibits insulin secretion from pancreatic β-cells, and in turn, insulin stimulates leptin biosynthesis and secretion from adipose tissue. Dysfunction of this adipoinsular feedback loop has been proposed to be involved in the development of hyperinsulinemia and type 2 diabetes mellitus. At the molecular level, leptin acts through various pathways, which in combination confer inhibitory effects on insulin biosynthesis and secretion. The aim of this study was to identify molecular mechanisms of leptin action on insulin secretion in pancreatic β-cells. To identify novel leptin-regulated genes, we performed subtraction PCR in INS-1 β-cells. Regulated expression of identified genes was confirmed by RT-PCR and Northern and Western blotting. Furthermore, functional impact on β-cell function was characterized by insulin-secretion assays, intracellular Ca²(+) concentration measurements, and enzyme activity assays. PP-1α, the catalytic subunit of protein phosphatase 1 (PP-1), was identified as a novel gene down-regulated by leptin in INS-1 pancreatic β-cells. Expression of PP-1α was verified in human pancreatic sections. PP-1α mRNA and protein expression is down-regulated by leptin, which culminates in reduction of PP-1 enzyme activity in β-cells. In addition, glucose-induced insulin secretion was inhibited by nuclear inhibitor of PP-1 and calyculin A, which was in part mediated by a reduction of PP-1-dependent calcium influx into INS-1 β-cells. These results identify a novel molecular pathway by which leptin confers inhibitory action on insulin secretion, and impaired PP-1 inhibition by leptin may be involved in dysfunction of the adipoinsular axis during the development of hyperinsulinemia and type 2 diabetes mellitus.

  12. Orthologs of Human Disease Associated Genes and RNAi Analysis of Silencing Insulin Receptor Gene in Bombyx mori

    Directory of Open Access Journals (Sweden)

    Zan Zhang

    2014-10-01

    Full Text Available The silkworm, Bombyx mori L., is an important economic insect that has been domesticated for thousands of years to produce silk. It is our great interest to investigate the possibility of developing the B. mori as human disease model. We searched the orthologs of human disease associated genes in the B. mori by bi-directional best hits of BLAST and confirmed by searching the OrthoDB. In total, 5006 genes corresponding to 1612 kinds of human diseases had orthologs in the B. mori, among which, there are 25 genes associated with diabetes mellitus. Of these, we selected the insulin receptor gene of the B. mori (Bm-INSR to study its expression in different tissues and at different developmental stages and tissues. Quantitative PCR showed that Bm-INSR was highly expressed in the Malpighian tubules but expressed at low levels in the testis. It was highly expressed in the 3rd and 4th instar larvae, and adult. We knocked down Bm-INSR expression using RNA interference. The abundance of Bm-INSR transcripts were dramatically reduced to ~4% of the control level at 6 days after dsRNA injection and the RNAi-treated B. mori individuals showed apparent growth inhibition and malformation such as abnormal body color in black, which is the typical symptom of diabetic patients. Our results demonstrate that B. mori has potential use as an animal model for diabetic mellitus research.

  13. The SNARE protein SNAP23 and the SNARE-interacting protein Munc18c in human skeletal muscle are implicated in insulin resistance/type 2 diabetes

    DEFF Research Database (Denmark)

    Boström, Pontus; Andersson, Linda; Vind, Birgitte

    2010-01-01

    /cytosolic compartment in the patients with the type 2 diabetes. Expression of the SNARE-interacting protein Munc18c was higher in skeletal muscle from patients with type 2 diabetes. Studies in L6 cells showed that Munc18c promoted the expression of SNAP23. CONCLUSIONS: We have translated our previous in vitro results......OBJECTIVE: Our previous studies suggest that the SNARE protein synaptosomal-associated protein of 23 kDa (SNAP23) is involved in the link between increased lipid levels and insulin resistance in cardiomyocytes. The objective was to determine whether SNAP23 may also be involved in the known...... association between lipid accumulation in skeletal muscle and insulin resistance/type 2 diabetes in humans, as well as to identify a potential regulator of SNAP23. RESEARCH DESIGN AND METHODS: We analyzed skeletal muscle biopsies from patients with type 2 diabetes and healthy, insulin-sensitive control...

  14. Molecularly imprinted polymer cartridges coupled on-line with high performance liquid chromatography for simple and rapid analysis of human insulin in plasma and pharmaceutical formulations.

    Science.gov (United States)

    Moein, Mohammad Mahdi; Javanbakht, Mehran; Akbari-adergani, Behrouz

    2014-04-01

    In this paper, a novel method is described for automated determination of human insulin in biological fluids using principle of sequential injection on a molecularly imprinted solid-phase extraction (MISPE) cartridge as a sample clean-up technique combined with high performance liquid chromatography (HPLC). The water-compatible molecularly imprinted polymers (MIPs) were prepared using methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, chloroform as a porogen and insulin as a template molecule. The imprinted polymers were then employed as the solid-phase extraction sorbent for on-line extraction of insulin from human plasma samples. To achieve the best condition, influential parameters on the extraction efficiency were thoroughly investigated. Rapid and simple analysis of the hormone was successfully accomplished through the good selectivity of the prepared sorbent coupled with HPLC. Limits of detection (LOD) and quantification (LOQ) of 0.2 ng mL(-1), 0.7 ng mL(-1), and 0.03 ng mL(-1), 0.1 ng mL(-1) were obtained in plasma and urine respectively. The obtained data exhibited the great recoveries for extraction of insulin from human plasma and pharmaceutical samples, higher than 87%.

  15. Bisphenol-A impairs insulin action and up-regulates inflammatory pathways in human subcutaneous adipocytes and 3T3-L1 cells.

    Science.gov (United States)

    Valentino, Rossella; D'Esposito, Vittoria; Passaretti, Federica; Liotti, Antonietta; Cabaro, Serena; Longo, Michele; Perruolo, Giuseppe; Oriente, Francesco; Beguinot, Francesco; Formisano, Pietro

    2013-01-01

    Current evidence indicates that chemical pollutants may interfere with the homeostatic control of nutrient metabolism, thereby contributing to the increased prevalence of metabolic disorders. Bisphenol-A (BPA) is a lipophilic compound contained in plastic which is considered a candidate for impairing energy and glucose metabolism. We have investigated the impact of low doses of BPA on adipocyte metabolic functions. Human adipocytes derived from subcutaneous adipose tissue and differentiated 3T3-L1 cells were incubated with BPA, in order to evaluate the effect on glucose utilization, insulin sensitivity and cytokine secretion. Treatment with 1 nM BPA significantly inhibited insulin-stimulated glucose utilization, without grossly interfering with adipocyte differentiation. Accordingly, mRNA levels of the adipogenic markers PPARγ and GLUT4 were unchanged upon BPA exposure. BPA treatment also impaired insulin-activated receptor phosphorylation and signaling. Moreover, adipocyte incubation with BPA was accompanied by increased release of IL-6 and IFN-γ, as assessed by multiplex ELISA assays, and by activation of JNK, STAT3 and NFkB pathways. Treatment of the cells with the JNK inhibitor SP600125 almost fully reverted BPA effect on insulin signaling and glucose utilization. In conclusion, low doses of BPA interfere with inflammatory/insulin signaling pathways, leading to impairment of adipose cell function.

  16. Bisphenol-A impairs insulin action and up-regulates inflammatory pathways in human subcutaneous adipocytes and 3T3-L1 cells.

    Directory of Open Access Journals (Sweden)

    Rossella Valentino

    Full Text Available Current evidence indicates that chemical pollutants may interfere with the homeostatic control of nutrient metabolism, thereby contributing to the increased prevalence of metabolic disorders. Bisphenol-A (BPA is a lipophilic compound contained in plastic which is considered a candidate for impairing energy and glucose metabolism. We have investigated the impact of low doses of BPA on adipocyte metabolic functions. Human adipocytes derived from subcutaneous adipose tissue and differentiated 3T3-L1 cells were incubated with BPA, in order to evaluate the effect on glucose utilization, insulin sensitivity and cytokine secretion. Treatment with 1 nM BPA significantly inhibited insulin-stimulated glucose utilization, without grossly interfering with adipocyte differentiation. Accordingly, mRNA levels of the adipogenic markers PPARγ and GLUT4 were unchanged upon BPA exposure. BPA treatment also impaired insulin-activated receptor phosphorylation and signaling. Moreover, adipocyte incubation with BPA was accompanied by increased release of IL-6 and IFN-γ, as assessed by multiplex ELISA assays, and by activation of JNK, STAT3 and NFkB pathways. Treatment of the cells with the JNK inhibitor SP600125 almost fully reverted BPA effect on insulin signaling and glucose utilization. In conclusion, low doses of BPA interfere with inflammatory/insulin signaling pathways, leading to impairment of adipose cell function.

  17. Human Monoclonal Islet Cell Antibodies From a Patient with Insulin- Dependent Diabetes Mellitus Reveal Glutamate Decarboxylase as the Target Antigen

    Science.gov (United States)

    Richter, Wiltrud; Endl, Josef; Eiermann, Thomas H.; Brandt, Michael; Kientsch-Engel, Rosemarie; Thivolet, Charles; Jungfer, Herbert; Scherbaum, Werner A.

    1992-09-01

    The autoimmune phenomena associated with destruction of the β cell in pancreatic islets and development of type 1 (insulin-dependent) diabetes mellitus (IDDM) include circulating islet cell antibodies. We have immortalized peripheral blood lymphocytes from prediabetic individuals and patients with newly diagnosed IDDM by Epstein-Barr virus transformation. IgG-positive cells were selected by anti-human IgG-coupled magnetic beads and expanded in cell culture. Supernatants were screened for cytoplasmic islet cell antibodies using the conventional indirect immunofluorescence test on cryostat sections of human pancreas. Six islet cell-specific B-cell lines, originating from a patient with newly diagnosed IDDM, could be stabilized on a monoclonal level. All six monoclonal islet cell antibodies (MICA 1-6) were of the IgG class. None of the MICA reacted with human thyroid, adrenal gland, anterior pituitary, liver, lung, stomach, and intestine tissues but all six reacted with pancreatic islets of different mammalian species and, in addition, with neurons of rat cerebellar cortex. MICA 1-6 were shown to recognize four distinct antigenic epitopes in islets. Islet cell antibody-positive diabetic sera but not normal human sera blocked the binding of the monoclonal antibodies to their target epitopes. Immunoprecipitation of 35S-labeled human islet cell extracts revealed that a protein of identical size to the enzyme glutamate decarboxylase (EC 4.1.1.15) was a target of all MICA. Furthermore, antigen immunotrapped by the MICA from brain homogenates showed glutamate decarboxylase enzyme activity. MICA 1-6 therefore reveal glutamate decarboxylase as the predominant target antigen of cytoplasmic islet cell autoantibodies in a patient with newly diagnosed IDDM.

  18. Expression of human apolipoprotein E4 reduces insulin-receptor substrate 1 expression and Akt phosphorylation in the ageing liver

    Directory of Open Access Journals (Sweden)

    Qi-Rui Ong

    2014-01-01

    Full Text Available The diabetic drug rosiglitazone was reported to improve glucose tolerance in insulin-resistant ApoE3 but not ApoE4 knock-in mice. We therefore examined whether apolipoprotein E (ApoE has genotype-specific effects on liver insulin function. At 12 weeks, no difference in liver insulin signaling was detected between fasting ApoE3 and ApoE4 mice. At 72 weeks however, ApoE4 mice had lower IRS-1 and PI3K expression, and reduced Akt phosphorylation. This decline was associated with lower insulin and higher glucose in ApoE4 mouse liver. Liver cholesterol was not affected. These results show that ApoE4 expression reduces liver insulin signaling and insulin levels, leading to higher glucose content.

  19. Structural and functional characterization of pathogenic non- synonymous genetic mutations of human insulin-degrading enzyme by in silico methods.

    Science.gov (United States)

    Shaik, Noor A; Kaleemuddin, Mohammed; Banaganapalli, Babajan; Khan, Fazal; Shaik, Nazia S; Ajabnoor, Ghada; Al-Harthi, Sameer E; Bondagji, Nabeel; Al-Aama, Jumana Y; Elango, Ramu

    2014-04-01

    Insulin-degrading enzyme (IDE) is a key protease involved in degrading insulin and amyloid peptides in human body. Several non-synonymous genetic mutations of IDE gene have been recently associated with susceptibility to both diabetes and Alzheimer's diseases. However, the consequence of these mutations on the structure of IDE protein and its substrate binding characteristics is not well elucidated. The computational investigation of genetic mutation consequences on structural level of protein is recently found to be an effective alternate to traditional in vivo and in vitro approaches. Hence, by using a combination of empirical rule and support vector machine based in silico algorithms, this study was able to identify that the pathogenic nonsynonymous genetic mutations corresponding to p.I54F, p.P122T, p.T533R, p.P581A and p.Y609A have more potential role in structural and functional deviations of IDE activity. Moreover, molecular modeling and secondary structure analysis have also confirmed their impact on the stability and secondary properties of IDE protein. The molecular docking analysis of IDE with combinational substrates has revealed that peptide inhibitors compared to small non-peptide inhibitor molecules possess good inhibitory activity towards mutant IDE. This finding may pave a way to design novel potential small peptide inhibitors for mutant IDE. Additionally by un-translated region (UTR) scanning analysis, two regulatory pathogenic genetic mutations i.e., rs5786997 (3' UTR) and rs4646954 (5' UTR), which can influence the translation pattern of IDE gene through sequence alteration of upstream-Open Reading Frame and Internal Ribosome Entry Site elements were identified. Our findings are expected to help in narrowing down the number of IDE genetic variants to be screened for disease association studies and also to select better competitive inhibitors for IDE related diseases.

  20. Human conditions of insulin-like growth factor-I (IGF-I deficiency

    Directory of Open Access Journals (Sweden)

    Puche Juan E

    2012-11-01

    Full Text Available Abstract Insulin-like growth factor I (IGF-I is a polypeptide hormone produced mainly by the liver in response to the endocrine GH stimulus, but it is also secreted by multiple tissues for autocrine/paracrine purposes. IGF-I is partly responsible for systemic GH activities although it possesses a wide number of own properties (anabolic, antioxidant, anti-inflammatory and cytoprotective actions. IGF-I is a closely regulated hormone. Consequently, its logical therapeutical applications seems to be limited to restore physiological circulating levels in order to recover the clinical consequences of IGF-I deficiency, conditions where, despite continuous discrepancies, IGF-I treatment has never been related to oncogenesis. Currently the best characterized conditions of IGF-I deficiency are Laron Syndrome, in children; liver cirrhosis, in adults; aging including age-related-cardiovascular and neurological diseases; and more recently, intrauterine growth restriction. The aim of this review is to summarize the increasing list of roles of IGF-I, both in physiological and pathological conditions, underlying that its potential therapeutical options seem to be limited to those proven states of local or systemic IGF-I deficiency as a replacement treatment, rather than increasing its level upper the normal range.

  1. Insulin aspart in diabetic pregnancy

    DEFF Research Database (Denmark)

    Mathiesen, Elisabeth R

    2008-01-01

    Pregnancy in women with diabetes is associated with an increased risk of obstetric complications and perinatal mortality. Maintenance of near-normal glycemia during pregnancy can bring the prevalence of fetal, neonatal and maternal complications closer to that of the nondiabetic population. Changes...... hyperglycemia with a tendency towards fewer episodes of severe hypoglycemia compared with human insulin. Treatment with insulin aspart was associated with a tendency toward fewer fetal losses and preterm deliveries than treatment with human insulin. Insulin aspart could not be detected in the fetal circulation...

  2. Site-specific covalent modifications of human insulin by catechol estrogens: Reactivity and induced structural and functional changes

    Science.gov (United States)

    Ku, Ming-Chun; Fang, Chieh-Ming; Cheng, Juei-Tang; Liang, Huei-Chen; Wang, Tzu-Fan; Wu, Chih-Hsing; Chen, Chiao-Chen; Tai, Jung-Hsiang; Chen, Shu-Hui

    2016-06-01

    Proteins, covalently modified by catechol estrogens (CEs), were identified recently from the blood serum of diabetic patients and referred to as estrogenized proteins. Estrogenization of circulating insulin may occur and affect its molecular functioning. Here, the chemical reactivity of CEs towards specific amino acid residues of proteins and the structural and functional changes induced by the estrogenization of insulin were studied using cyclic voltammetry, liquid chromatography-mass spectrometry, circular dichroism spectroscopy, molecular modeling, and bioassays. Our results indicate that CEs, namely, 2- and 4-hydroxyl estrogens, were thermodynamically and kinetically more reactive than the catechol moiety. Upon co-incubation, intact insulin formed a substantial number of adducts with one or multiple CEs via covalent conjugation at its Cys 7 in the A or B chain, as well as at His10 or Lys29 in the B chain. Such conjugation was coupled with the cleavage of inter-chain disulfide linkages. Estrogenization on these sites may block the receptor-binding pockets of insulin. Insulin signaling and glucose uptake levels were lower in MCF-7 cells treated with modified insulin than in cells treated with native insulin. Taken together, our findings demonstrate that insulin molecules are susceptible to active estrogenization, and that such modification may alter the action of insulin.

  3. Pinitol Supplementation Does Not Affect Insulin-Mediated Glucose Metabolism and Muscle Insulin Receptor Content and Phosphorylation in Older Humans12

    OpenAIRE

    Campbell, Wayne W.; Haub, Mark D.; Fluckey, James D.; Ostlund, Richard E.; Thyfault, John P.; Morse-Carrithers, Hannah; Hulver, Matthew W.; Birge, Zonda K.

    2004-01-01

    This study assessed the effect of oral pinitol supplementation on oral and intravenous glucose tolerances and on skeletal muscle insulin receptor content and phosphorylation in older people. Fifteen people (6 men, 9 women; age 66 ± 8 y; BMI 27.9 ± 3.3 kg/m2; hemoglobin A1c 5.39 ± 0.46%, mean ± SD) completed a 7-wk protocol. Subjects were randomly assigned to groups that during wk 2−7 consumed twice daily either a non-nutritive beverage (Placebo group, n = 8) or the same beverage with 1000 mg ...

  4. Interaction between Fibrinogen and Insulin-Like Growth Factor-Binding Protein-1 in Human Plasma under Physiological Conditions.

    Science.gov (United States)

    Gligorijević, N; Nedić, O

    2016-02-01

    Fibrinogen is a plasma glycoprotein and one of the principle participants in blood coagulation. It interacts with many proteins during formation of a blood clot, including insulin-like growth factors (IGFs) and their binding proteins (IGFBP). Fibrinogen complexes were found as minor fractions in fibrinogen preparations independently of the coagulation process, and their presence influences the kinetics of polymerization. The idea of this work was to investigate whether fibrinogen in human plasma interacts with IGFBPs independently of the tissue injury or coagulation process. The results have shown that fibrinogen forms complexes with IGFBP-1 under physiological conditions. Several experimental approaches have confirmed that complexes are co-isolated with fibrinogen from plasma, they are relatively stable, and they appear as a general feature of human plasma. Several other experiments excluded the possibility that alpha-2 macroglobulin/IGFBP-1 complexes or IGFBP-1 oligomers contributed to IGFBP-1 immunoreactivity. The role of fibrinogen/IGFBP-1 complexes is still unknown. Further investigation in individuals expressing both impaired glucose control and coagulopathy could contribute to identification and understanding of their possible physiological role.

  5. Differential half-maximal effects of human insulin and its analogs for in situ glucose transport and protein synthesis in rat soleus muscle

    Science.gov (United States)

    Weinstein, Randi B.; Eleid, Noura; LeCesne, Catherine; Durando, Bianca; Crawford, Julie T.; Heffner, Michelle; Layton, Christle; O'Keefe, Matthew; Robinson, Jennifer; Rudinsky, Suzy; Henriksen, Erik J.; Tischler, Marc E.

    2002-01-01

    Analogs of human insulin have been used to discriminate between responses of metabolic and mitogenic (growth-related) pathways. This study compared the stimulatory effects of human insulin (HI) and 2 analogs (X2, B-Asp(9), B-Glu(27) and H2, A-His(8),B-His(4),B-Glu(10), B-His(27)) on glucose uptake and protein synthesis in rat soleus muscle in situ. Glucose uptake, estimated by intramuscular (IM) injection of 2-deoxy[1,2-3H]glucose with or without insulin, was maximally increased at 10(-6) mol/L for HI and X2 and 10(-7) mol/L for H2. HI had a larger effect (318%) than either X2 (156%) or H2 (124%). The half-maximal effect (ED(50)) values for HI, X2, and H2 were 3.3 x10(-8) mol/L, 1.7 x 10(-7) mol/L, and 1.6 x 10(-9) mol/L, respectively. Protein synthesis, estimated by protein incorporation of [(3)H]phenylalanine injected into muscles with or without insulin, was maximally increased at 10(-5) mol/L for HI and 10(-6) for X2 and H2. HI had a larger effect in stimulating protein synthesis (34%) than either X2 (25%) or H2 (19.8%). The ED(50) values for HI, X2, and H2 were 3.0 x 10(-7) mol/L, 3.2 x 10(-7) mol/L, and 1.0 x 10(-9) mol/L, respectively. The biological potency of each analog (ED(50)insulin/ED(50)analog) showed X2 to be less potent than HI for both glucose uptake (0.2) and protein synthesis (0.9), whereas H2 is more potent than HI with ratios of 20 and 300, respectively. These data suggest that this approach for studying insulin responsiveness in a single muscle in situ may be a useful tool for investigating insulin signaling in muscle in vivo. Copyright 2002, Elsevier Science (USA). All rights reserved.

  6. Leptin replacement improves postprandial glycemia and insulin sensitivity in human immunodeficiency virus-infected lipoatrophic men treated with pioglitazone: a pilot study.

    Science.gov (United States)

    Magkos, Faidon; Brennan, Aoife; Sweeney, Laura; Kang, Eun Seok; Doweiko, John; Karchmer, Adolf W; Mantzoros, Christos S

    2011-07-01

    Highly active antiretroviral therapy (HAART)-induced lipoatrophy is characterized by hypoleptinemia and insulin resistance. Evidence suggests that pioglitazone and recombinant methionyl human leptin (metreleptin) administration has beneficial effects in human immunodeficiency virus (HIV)-infected lipoatrophic patients. This proof-of-concept study aimed at evaluating whether the combination of metreleptin and pioglitazone has favorable effects, above and beyond pioglitazone alone, on both metabolic outcomes and peripheral lipoatrophy in HIV-infected patients on HAART. Nine HIV-positive men with at least 6 months of HAART exposure, clinical evidence of lipoatrophy, and low leptin concentrations (≤4 ng/mL) were placed on pioglitazone treatment (30 mg/d per os) and were randomized to receive either metreleptin (0.04 mg/kg subcutaneously once daily; n = 5) or placebo (n = 4) for 3 months in a double-blinded fashion. Compared with placebo, metreleptin reduced fasting serum insulin concentration, increased adiponectin concentration, reduced the homeostasis model assessment index of insulin resistance, and attenuated postprandial glycemia in response to a mixed meal (all P ≤ .02), but did not affect trunk and peripheral fat mass. HIV control was not affected, and no major adverse effects were observed. Metreleptin administration in HIV-positive, leptin-deficient patients with lipoatrophy treated with pioglitazone improves postprandial glycemia and insulin sensitivity. Results from this pilot study should be confirmed in larger clinical trials.

  7. The proteomic signature of insulin-resistant human skeletal muscle reveals increased glycolytic and decreased mitochondrial enzymes

    DEFF Research Database (Denmark)

    Giebelstein, J; Poschmann, G; Højlund, K

    2012-01-01

    The molecular mechanisms underlying insulin resistance in skeletal muscle are incompletely understood. Here, we aimed to obtain a global picture of changes in protein abundance in skeletal muscle in obesity and type 2 diabetes, and those associated with whole-body measures of insulin action....

  8. Insulin and Glucose Alter Death-Associated Protein Kinase 3 (DAPK3) DNA Methylation in Human Skeletal Muscle

    DEFF Research Database (Denmark)

    Mudry, Jonathan M; Lassiter, David G; Nylén, Carolina

    2016-01-01

    DNA methylation is altered by environmental factors. We hypothesized DNA methylation is altered in skeletal muscle in response to either insulin or glucose exposure. We performed a genome-wide DNA methylation analysis in muscle from healthy men before and after insulin exposure. DNA methylation...... of selected genes was determined in muscle from healthy and type 2 diabetic men before and after a glucose tolerance test. Insulin altered DNA methylation in the 3'UTR of the calcium pump ATP2A3 gene. Insulin increased DNA methylation in the gene body of DAPK3, a gene involved in cell proliferation, apoptosis...... glucose incorporation to glycogen was unaltered by siRNA against DAPK3, palmitate oxidation was increased. In conclusion, insulin and glucose exposure acutely alter the DNA methylation profile of skeletal muscle, indicating DNA methylation constitutes a rapidly and adaptive epigenetic mark. Furthermore...

  9. Genetically Determined Insulin Resistance is Characterized by Down-Regulation of Mitochondrial Oxidative Metabolism in Human Skeletal Muscle

    DEFF Research Database (Denmark)

    Kristensen, Jonas M; Skov, Vibe; Wojtaszewski, Jørgen

    2010-01-01

    Transcriptional profiling of skeletal muscle from patients with type 2 diabetes and high-risk individuals have demonstrated a co-ordinated down-regulation of oxidative phosphorylation (OxPhos) genes, suggesting a link between insulin resistance and mitochondrial dysfunction. However, whether...... mitochondrial dysfunction is a cause or consequence of insulin resistance remains to be clarified. In the present study, we tested the hypothesis that mitochondrial oxidative metabolism was down-regulated in skeletal muscle of patients with genetically determined insulin resistance. Skeletal muscle biopsies.......02), and complex V (ATP5B; p=0.005). Our data demonstrate that genetically determined insulin resistance is associated with a co-ordinated down-regulation of OxPhos components both at the transcriptional and translational level. These findings suggest that an impaired biological response to insulin in skeletal...

  10. Inconsistent formation and nonfunction of insulin-positive cells from pancreatic endoderm derived from human embryonic stem cells in athymic nude rats.

    Science.gov (United States)

    Matveyenko, Aleksey V; Georgia, Senta; Bhushan, Anil; Butler, Peter C

    2010-11-01

    Embryonic stem cell therapy has been proposed as a therapeutic strategy to restore β-cell mass and function in T1DM. Recently, a group from Novocell (now ViaCyte) reported successful development of glucose-responsive islet-like structures after implantation of pancreatic endoderm (PE) derived from human embryonic stem cells (hESC) into immune-deficient mice. Our objective was to determine whether implantation of hESC-derived pancreatic endoderm from Novocell into athymic nude rats results in development of viable glucose-responsive pancreatic endocrine tissue. Athymic nude rats were implanted with PE derived from hESC either via implantation into the epididymal fat pads or by subcutaneous implantation into TheraCyte encapsulation devices for 20 wk. Blood glucose, weight, and human insulin/C-peptide secretion were monitored by weekly blood draws. Graft β-cell function was assessed by a glucose tolerance test, and graft morphology was assessed by immunohistochemistry and immunofluorescence. At 20 wk postimplantation, epididymal fat-implanted PE progressed to develop islet-like structures in 50% of implants, with a mean β-cell fractional area of 0.8 ± 0.3%. Human C-peptide and insulin were detectable, but at very low levels (C-peptide = 50 ± 26 pmol/l and insulin = 15 ± 7 pmol/l); however, there was no increase in human C-peptide/insulin levels after glucose challenge. There was no development of viable pancreatic tissue or meaningful secretory function when human PE was implanted in the TheraCyte encapsulation devices. These data confirm that islet-like structures develop from hESC differentiated to PE by the protocol developed by NovoCell. However, the extent of endocrine cell formation and secretory function is not yet sufficient to be clinically relevant.

  11. KU-32, a Novel Drug for Diabetic Neuropathy, Is Safe for Human Islets and Improves In Vitro Insulin Secretion and Viability

    Directory of Open Access Journals (Sweden)

    Kevin Farmer

    2012-01-01

    Full Text Available KU-32 is a novel, novobiocin-based Hsp90 inhibitor that protects against neuronal glucotoxicity and reverses multiple clinical indices of diabetic peripheral neuropathy in a rodent model. However, any drug with potential for treating diabetic complications must also have no adverse effects on the function of pancreatic islets. Thus, the goal of the current study was to assess the effect of KU-32 on the in vitro viability and function of human islets. Treating human islets with KU-32 for 24 hours showed no toxicity as assessed using the alamarBlue assay. Confocal microscopy confirmed that with a minimum of 2-day exposure, KU-32 improved cellular viability by blocking apoptosis. Functionally, isolated human islets released more glucose-stimulated insulin when preincubated in KU-32. However, diabetic BKS-db/db mice, a model for type 2 diabetes, administered KU-32 for 10 weeks did not show any significant changes in blood glucose and insulin levels, despite having greater insulin staining/beta cell in the pancreas compared to untreated BKS db/db mice. In summary, KU-32 did not harm isolated human islets and may even be protective. However, the effect does not appear significant enough to alter the in vivo metabolic parameters of diabetic mice.

  12. KU-32, a novel drug for diabetic neuropathy, is safe for human islets and improves in vitro insulin secretion and viability.

    Science.gov (United States)

    Farmer, Kevin; Williams, S Janette; Novikova, Lesya; Ramachandran, Karthik; Rawal, Sonia; Blagg, Brian S J; Dobrowsky, Rick; Stehno-Bittel, Lisa

    2012-01-01

    KU-32 is a novel, novobiocin-based Hsp90 inhibitor that protects against neuronal glucotoxicity and reverses multiple clinical indices of diabetic peripheral neuropathy in a rodent model. However, any drug with potential for treating diabetic complications must also have no adverse effects on the function of pancreatic islets. Thus, the goal of the current study was to assess the effect of KU-32 on the in vitro viability and function of human islets. Treating human islets with KU-32 for 24 hours showed no toxicity as assessed using the alamarBlue assay. Confocal microscopy confirmed that with a minimum of 2-day exposure, KU-32 improved cellular viability by blocking apoptosis. Functionally, isolated human islets released more glucose-stimulated insulin when preincubated in KU-32. However, diabetic BKS-db/db mice, a model for type 2 diabetes, administered KU-32 for 10 weeks did not show any significant changes in blood glucose and insulin levels, despite having greater insulin staining/beta cell in the pancreas compared to untreated BKS db/db mice. In summary, KU-32 did not harm isolated human islets and may even be protective. However, the effect does not appear significant enough to alter the in vivo metabolic parameters of diabetic mice.

  13. Evaluation of the maximum beyond-use-date stability of regular human insulin extemporaneously prepared in 0.9% sodium chloride in a polyvinyl chloride bag

    Directory of Open Access Journals (Sweden)

    Rocchio MA

    2013-10-01

    Full Text Available Megan A Rocchio, Caryn D Belisle, Bonnie C Greenwood, Michael C Cotugno, Paul M SzumitaDepartment of Pharmacy, Brigham and Women's Hospital, Boston, MA, USABackground: Regular human insulin 100 units added to a sufficient quantity of 0.9% sodium chloride, to yield a total volume of 100 mL within a polyvinylchloride bag, is accepted to be stable for 24 hours due to physical denaturation and chemical modification. The objective of this study was to evaluate the extended stability of such extemporaneously prepared regular human insulin, stored under refrigeration, to the maximum beyond-use-date allowed by United States Pharmacopeia chapter 797.Methods: At time “0” three admixtures of regular human insulin were prepared by withdrawing 1 mL of regular human insulin with a concentration of 100 units/mL and adding it to a sufficient quantity of 0.9% sodium chloride for injection in a polyvinylchloride bag to yield a total volume of 100 mL. The three admixtures were stored under refrigeration (2°C–8°C [36°F–46°F], and one sample of each admixture was withdrawn and tested in duplicate at 0, 6, 24, 48, 72, 144, 168, 192, 216, 240, 312, and 336 hours. Utilizing high performance liquid chromatography, each sample underwent immediate testing. The time points were stable if the mean concentration of the samples exceeded 90% of the equilibrium concentration at 6 hours.Results: The equilibrium concentration was 0.89 units/mL. Time points were stable if the mean concentration was at least 0.80 units/mL. All time points retained at least 90% of the equilibrium concentration, with the exception of hour 168 (0.79 ± 0.03 units/mL. At 192 hours the mean concentration was 0.88 ± 0.03 units/mL. At 336 hours the mean concentration was 0.91 ± 0.02 units/mL.Conclusion: Based on these results, regular human insulin 100 units added to 0.9% sodium chloride for injection in a polyvinylchloride bag to yield a total volume of 100 mL is stable for up to 336 hours

  14. Efficacy and safety of insulin aspart versus regular human insulin for women with gestational diabetes mellitus%门冬胰岛素治疗妊娠期糖尿病的疗效观察

    Institute of Scientific and Technical Information of China (English)

    周莉; 范玲

    2012-01-01

    Objective To explore the efficacy and safety of human aspart versus regular human insulin in women with gestational diabetes mellitus (GDM).Methods A total of 80 women with GDM during pregnancy delivered at our hospital divided into 2 groups:Group 1 with human aspart and regular human insulin N while Group 2 with regular human insulin R and N.The levels of glucose were compared before and after 2 h at breakfast,lunch and supper at Day 1,3 and 5.And the outcomes of women and their babies were evaluated.Results No significant difference in general characteristics existed between two groups.Except for breakfast of Day 3,no significant difference was found in terms of the amount of insulin,the time of satisfactory glucose level and delivery time point,etc.There was no significant inter-group difference in the outcomes of pregnant women and their babies.Conclusion The efficacy and safety of human aspart or regular human insulin are comparable for the women with gestational diabetes mellitus.%目的 探讨门冬胰岛素在治疗妊娠期糖尿病孕妇(GDM)的疗效.方法 经医院伦理委员会审核通过,孕妇自愿签署统一的知情同意书.将需要胰岛素治疗的GDM孕妇按1∶1配对,共80例孕妇,分为门冬胰岛素组和生物合成人胰岛素组各40例,比较两组第1、3、5天3餐餐后2h血糖以及母婴结局.结果 两组孕妇比较使用胰岛素治疗后第1、3、5天3餐后2h血糖,仅第3天早餐后2h血糖门冬胰岛素组(6.9±0.9)mmol/L,生物合成胰岛素组(7.5±1.4) mmol/L,两组比较差异有统计学意义,P<0.05.两组孕妇胰岛素用量、血糖达标时间、分娩孕周等差异无统计学意义,P>0.05,孕妇满意度门冬胰岛素组87.5%,生物合成人胰岛素组75%,差异有统计学意义,P<0.01.两组孕妇并发症及新生儿结局差异均无统计学意义(均P>0.05).结论 门冬胰岛素治疗GDM孕妇安全有效.

  15. Insulin-like growth factor I enhances collagen synthesis in engineered human tendon tissue

    DEFF Research Database (Denmark)

    Herchenhan, Andreas; Bayer, Monika L.; Eliasson, Pernilla

    2015-01-01

    OBJECTIVE: Isolated human tendon cells form 3D tendon constructs that demonstrate collagen fibrillogenesis and feature structural similarities to tendon when cultured under tensile load. The exact role of circulating growth factors for collagen formation in tendon is sparsely examined. We investi...

  16. Cephalic phase secretion of insulin and other enteropancreatic hormones in humans

    DEFF Research Database (Denmark)

    Veedfald, Simon; Plamboeck, Astrid; Deacon, Carolyn F

    2016-01-01

    Enteropancreatic hormone secretion is thought to include a cephalic phase, but the evidence in humans is ambiguous. We studied vagally induced gut hormone responses with and without muscarinic blockade in 10 glucose-clamped healthy men (age: 24.5 ± 0.6 yr, means ± SE; body mass index: 24.0 ± 0.5 ...

  17. Human insulin-like growth factor 1-transfected umbilical cord blood neural stem cell transplantation improves hypoxic-ischemic brain injury

    Institute of Scientific and Technical Information of China (English)

    Dengna Zhu; Yanjie Jia; Jun Wang; Boai Zhang; Guohui Niu; Yazhen Fan

    2011-01-01

    Human insulin-like growth factor 1-transfected umbilical cord blood neural stem cells were transplanted into a hypoxic-ischemic neonatal rat model via the tail vein.BrdU-positive cells at day 7post-transplantation,as well as nestin-and neuron specific enolase-positive cells at day 14 wereincreased compared with those of the single neural stem cell transplantation group.In addition,theproportion of neuronal differentiation was enhanced.The genetically modified cell-transplanted ratsexhibited enhanced performance in correctly crossing a Y-maze and climbing an angled slope compared with those of the single neural stem cell transplantation group.These results showed that human insulin-like growth factor 1-transfected neural stem cell transplantation promotes therecovery of the learning,memory and motor functions in hypoxic-ischemic rats.

  18. Human tumor cells induce angiogenesis through positive feedback between CD147 and insulin-like growth factor-I.

    Directory of Open Access Journals (Sweden)

    Yanke Chen

    Full Text Available Tumor angiogenesis is a complex process based upon a sequence of interactions between tumor cells and endothelial cells. Previous studies have shown that CD147 was correlated with tumor angiogenesis through increasing tumor cell secretion of vascular endothelial growth factor (VEGF and matrix metalloproteinases (MMPs. In this study, we made a three-dimensional (3D tumor angiogenesis model using a co-culture system of human hepatocellular carcinoma cells SMMC-7721 and humanumbilical vein endothelial cells (HUVECs in vitro. We found that CD147-expressing cancer cells could promote HUVECs to form net-like structures resembling the neo-vasculature, whereas the ability of proliferation, migration and tube formation of HUVECs was significantly decreased in tumor conditioned medium (TCM of SMMC-7721 cells transfected with specific CD147-siRNA. Furthermore, by assaying the change of pro-angiogenic factors in TCM, we found that the inhibition of CD147 expression led to significant decrease of VEGF and insulin-like growth factor-I (IGF-I secretion. Interestingly, we also found that IGF-I up-regulated the expression of CD147 in both tumor cells and HUVECs. These findings suggest that there is a positive feedback between CD147 and IGF-I at the tumor-endothelial interface and CD147 initiates the formation of an angiogenesis niche.

  19. HNF4α Antagonists Discovered by a High-Throughput Screen for Modulators of the Human Insulin Promoter

    Science.gov (United States)

    Kiselyuk, Alice; Lee, Seung-Hee; Farber-Katz, Suzette; Zhang, Mingjun; Athavankar, Sonalee; Cohen, Tom; Pinkerton, Anthony B.; Ye, Mao; Bushway, Paul; Richardson, Adam D.; Hostetler, Heather A.; Rodriguez-Lee, Mariam; Huang, Li; Spangler, Benjamin; Smith, Layton; Higginbotham, Jennifer; Cashman, John; Freeze, Hudson; Itkin-Ansari, Pamela; Dawson, Marcia I.; Schroeder, Friedhelm; Cang, Yong; Mercola, Mark; Levine, Fred

    2012-01-01

    SUMMARY Hepatocyte Nuclear Factor (HNF)4α is a central regulator of gene expression in cell types that play a critical role in metabolic homeostasis, including hepatocytes, enterocytes, and pancreatic β-cells. Although fatty acids were found to occupy the HNF4α ligand-binding pocket and proposed to act as ligands, there is controversy about both the nature of HNF4α ligands as well as the physiological role of the binding. Here, we report the discovery of potent synthetic HNF4α antagonists through a high-throughput screen for effectors of the human insulin promoter. These molecules bound to HNF4α with high affinity and modulated the expression of known HNF4α target genes. Notably, they were found to be selectively cytotoxic to cancer cell lines in vitro and in vivo, although in vivo potency was limited by suboptimal pharmacokinetic properties. The discovery of bioactive modulators for HNF4α raises the possibility that diseases involving HNF4α, such as diabetes and cancer, might be amenable to pharmacologic intervention by modulation of HNF4α activity. PMID:22840769

  20. Roles of sulfonylurea receptor 1 and multidrug resistance protein 1 in modulating insulin secretion in human insulinoma

    Institute of Scientific and Technical Information of China (English)

    Cheng-Jiang Li; Hua-Li Zhou; Jun Li; Hong-TianYao; Rong Su; Wen-Peng Li

    2011-01-01

    BACKGROUND: Sulfonylurea receptor 1 (SUR1) and multidrug resistance protein 1 (MRP1) are two prominent members of multidrug resistance proteins associated with insulin secretion. The aims of this study were to investigate their expression in insulinomas and their sole and synergistic effects in modulating abnormalinsulinsecretion. METHODS: Fasting glucose, insulin and C-peptide were measured in 11 insulinoma patients and 11 healthy controls. Prolonged oral glucose tolerance tests were performed in 6 insulinoma patients. Insulin content, SUR1 and MRP1 were detected in 11 insulinoma patients by immunohistochemistry. SUR1 and MRP1 were also detected in 6 insulinoma patients by immunofluorescence. RESULTS: Insulinoma patients presented the typical demons-trations of Whipple's triad. Fasting glucose of each insulinoma patient was lower than 2.8 mmol/L, and simultaneous insulin and C-peptide were increased in insulinoma patients. Prolonged oral glucose tolerance tests showed that insulin secretion in insulinoma patients were also stimulated by high glucose. Immunohistochemistry and immunofluorescence staining showed that SUR1 increased, but MRP1 decreased in insulinoma compared with the adjacent islets. CONCLUSIONS: The hypersecretion of insulin in insulinomas might be, at least partially, due to the enrichment of SUR1. In contrast, MRP1, which is down-regulated in insulinomas, might reflect a negative feedback in insulin secretion.

  1. Obesity-insulin targeted genes in the 3p26-25 region in human studies and LG/J and SM/J mice.

    Science.gov (United States)

    Kraja, Aldi T; Lawson, Heather A; Arnett, Donna K; Borecki, Ingrid B; Broeckel, Ulrich; de las Fuentes, Lisa; Hunt, Steven C; Province, Michael A; Cheverud, James; Rao, D C

    2012-08-01

    Identifying metabolic syndrome (MetS) genes is important for novel drug development and health care. This study extends the findings on human chromosome 3p26-25 for an identified obesity-insulin factor QTL, with an LOD score above 3. A focused association analysis comprising up to 9578 African American and Caucasian subjects from the HyperGEN Network (908 African Americans and 1025 whites), the Family Heart Study (3035 whites in time 1 and 1943 in time 2), and the Framingham Heart Study (1317 in Offspring and 1320 in Generation 3) was performed. The homologous mouse region was explored in an F(16) generation of an advanced intercross between the LG/J and SM/J inbred strains, in an experiment where 1002 animals were fed low-fat (247 males; 254 females) or high-fat (253 males; 248 females) diets. Association results in humans indicate pleiotropic effects for SNPs within or surrounding CNTN4 on obesity, lipids and blood pressure traits and for SNPs near IL5RA, TRNT1, CRBN, and LRRN1 on central obesity and blood pressure. Linkage analyses of this region in LG/J×SM/J mice identify a highly significant pleiotropic QTL peak for insulin and glucose levels, as well as response to glucose challenge. The mouse results show that insulin and glucose levels interact with high and low fat diets and differential gene expression was identified for Crbn and Arl8b. In humans, ARL8B resides ~137kbps away from BHLHE40, expression of which shows up-regulation in response to insulin treatment. This focused human genetic analysis, incorporating mouse research evidenced that 3p26-25 has important genetic contributions to MetS components. Several of the candidate genes have functions in the brain. Their interaction with MetS and the brain warrants further investigation.

  2. Obesity–insulin targeted genes in the 3p26-25 region in human studies and LG/J and SM/J mice

    Science.gov (United States)

    Kraja, Aldi T.; Lawson, Heather A.; Arnett, Donna K.; Borecki, Ingrid B.; Broeckel, Ulrich; de las Fuentes, Lisa; Hunt, Steven C.; Province, Michael A.; Cheverud, James; Rao, D.C.

    2012-01-01

    Identifying metabolic syndrome (MetS) genes is important for novel drug development and health care. This study extends the findings on human chromosome 3p26-25 for an identified obesity–insulin factor QTL, with an LOD score above 3. A focused association analysis comprising up to 9578 African American and Caucasian subjects from the HyperGEN Network (908 African Americans and 1025 whites), the Family Heart Study (3035 whites in time 1 and 1943 in time 2), and the Framingham Heart Study (1317 in Offspring and 1320 in Generation 3) was performed. The homologous mouse region was explored in an F16 generation of an advanced intercross between the LG/J and SM/J inbred strains, in an experiment where 1002 animals were fed low-fat (247 males; 254 females) or high-fat (253 males; 248 females) diets. Association results in humans indicate pleiotropic effects for SNPs within or surrounding CNTN4 on obesity, lipids and blood pressure traits and for SNPs near IL5RA, TRNT1, CRBN, and LRRN1 on central obesity and blood pressure. Linkage analyses of this region in LG/J × SM/J mice identify a highly significant pleiotropic QTL peak for insulin and glucose levels, as well as response to glucose challenge. The mouse results show that insulin and glucose levels interact with high and low fat diets and differential gene expression was identified for Crbn and Arl8b. In humans, ARL8B resides ~137 kbps away from BHLHE40, expression of which shows up-regulation in response to insulin treatment. This focused human genetic analysis, incorporating mouse research evidenced that 3p26-25 has important genetic contributions to MetS components. Several of the candidate genes have functions in the brain. Their interaction with MetS and the brain warrants further investigation. PMID:22386932

  3. Carob pulp preparation rich in insoluble dietary fibre and polyphenols increases plasma glucose and serum insulin responses in combination with a glucose load in humans.

    Science.gov (United States)

    Gruendel, Sindy; Otto, Baerbel; Garcia, Ada L; Wagner, Karen; Mueller, Corinna; Weickert, Martin O; Heldwein, Walter; Koebnick, Corinna

    2007-07-01

    Dietary fibre consumption is associated with improved glucose homeostasis. In contrast, dietary polyphenols have been suggested to exert both beneficial and detrimental effects on glucose and insulin metabolism. Recently, we reported that a polyphenol-rich insoluble dietary fibre preparation from carob pulp (carob fibre) resulted in lower postprandial acylated ghrelin levels after a liquid meal challenge test compared with a control meal without supplementation. The effects may, however, differ when a different food matrix is used. Thus, we investigated the effects of carob fibre on glucose, insulin and ghrelin responses in healthy humans in combination with a glucose load. In a randomized single-blind cross-over study involving twenty healthy subjects (aged 22-62 years), plasma glucose, total and acylated ghrelin, and serum insulin were repeatedly assessed before and after the ingestion of 200 ml water with 50 g glucose and 0, 5, 10 or 20 g carob fibre over a period of 180 min. The intake of 5 and 10 g carob fibre increased the plasma glucose by 47 % and 64 % (P carob-enriched glucose solution. Total ghrelin decreased only after 10 g carob fibre (P carob fibre, administered within a water-glucose solution, increases postprandial glucose and insulin responses, suggesting a deterioration in glycaemic control.

  4. The Role of Human Factors in the Design and Development of an Insulin Pump

    OpenAIRE

    Schaeffer, Noel E.

    2012-01-01

    This article discusses human factors (HF) processes and how they are applied during the development of a medical device to minimize the risk that the user interface design could lead to patient errors, adverse events, and product recalls. This process is best defined as “prevention through design.” The HF design process is exemplified by three distinct phases: (1) preliminary analysis, (2) formative design evaluation and modification, and (3) design validation. Additional benefits of employin...

  5. Insulin-like growth factor binding protein 1 and human embryonic development during 6-10 gestational weeks

    Institute of Scientific and Technical Information of China (English)

    方群; 王艳霞; 周祎

    2004-01-01

    Background Insulin-like growth factor binding protein-1 (IGFBP-1), which is a carrier of Insulin-like growth factors (IGFs) regulates the fetal development by working as an active factor controlling the combination of IGFs with their receptors. This study was designed to investigate the relationship between IGFBP-1 and human embryonic development during weeks 6 -10 of gestation.Methods A total of 44 pregnant women with singleton pregnancy were divided into two groups: one with abnormal embryo development (n = 32) and the other with normal embryo development (n = 12).Enzyme-linked immunosorbent assay (ELISA) was employed to detect IGFBP-1 levels in maternal serum and decidual tissue. The expression of IGFBP-1 mRNA in deciduas was examined by reverse transcription polymerase chain reaction (RT-PCR) technique.Results The level of IGFBP-1 protein in maternal serum was significantly higher in the abnormal group [ (125.36 ± 47.93) μg/ml] than in the normal group [(70.72 ± 21.21) μg/ml ]. Both of IGFBP-1 and IGFBP-1 mRNA in deciduas were higher in abnormal group [ (1.60 ± 1.39) μg/ml and 1.66 ± 1.64, respectively ] than in the normal group [ (0.35 ± 0.23) μg/mi and 0.40 ± 0.20,respectively]. The level of IGFBP-1 in maternal serum was positively correlated with IGFBP-1 mRNA (r=0. 90, P<0.05) and IGFBP-1 protein (r=0.92, P<0.05) in decidual tissue.Conclusions During weeks 6 -10 of gestation, abnormal embryonic development is correlated with elevated IGFBP-1. The level of IGFBP-1 in maternal serum is related to the concentrations of IGFBP1 mRNA and IGFBP-1 in decidual tissue. The IGFBP-1 level in maternal serum may be used as a predictive marker to evaluate embryonic development.

  6. A review of piscine islet xenotransplantation using wild-type tilapia donors and the production of transgenic tilapia expressing a "humanized" tilapia insulin.

    Science.gov (United States)

    Wright, James R; Yang, Hua; Hyrtsenko, Olga; Xu, Bao-You; Yu, Weiming; Pohajdak, Bill

    2014-01-01

    Most islet xenotransplantation laboratories have focused on porcine islets, which are both costly and difficult to isolate. Teleost (bony) fish, such as tilapia, possess macroscopically visible distinct islet organs called Brockmann bodies which can be inexpensively harvested. When transplanted into diabetic nude mice, tilapia islets maintain long-term normoglycemia and provide human-like glucose tolerance profiles. Like porcine islets, when transplanted into euthymic mice, they are rejected in a CD4 T-cell-dependent manner. However, unlike pigs, tilapia are so phylogenetically primitive that their cells do not express α(1,3)Gal and, because tilapia are highly evolved to live in warm stagnant waters nearly devoid of dissolved oxygen, their islet cells are exceedingly resistant to hypoxia, making them ideal for transplantation within encapsulation devices. Encapsulation, especially when combined with co-stimulatory blockade, markedly prolongs tilapia islet xenograft survival in small animal recipients, and a collaborator has shown function in diabetic cynomolgus monkeys. In anticipation of preclinical xenotransplantation studies, we have extensively characterized tilapia islets (morphology, embryologic development, cell biology, peptides, etc.) and their regulation of glucose homeostasis. Because tilapia insulin differs structurally from human insulin by 17 amino acids, we have produced transgenic tilapia whose islets stably express physiological levels of humanized insulin and have now bred these to homozygosity. These transgenic fish can serve as a platform for further development into a cell therapy product for diabetes.

  7. [Local lipohypertrophy in insulin treatment].

    Science.gov (United States)

    Herold, D A; Albrecht, G

    1993-01-01

    Local lipoatrophy and lipohypertrophy at injection sites are well known side effects of treatment with insulin. Conditions favouring these local complications are created when repeated or continuous injections are given into the same areas. We report on a 27-year-old female patient who suffered from persistent local swellings after use of an external pump which continuously injected human insulin via indwelling cannulas.

  8. The role of human factors in the design and development of an insulin pump.

    Science.gov (United States)

    Schaeffer, Noel E

    2012-03-01

    This article discusses human factors (HF) processes and how they are applied during the development of a medical device to minimize the risk that the user interface design could lead to patient errors, adverse events, and product recalls. This process is best defined as "prevention through design." The HF design process is exemplified by three distinct phases: (1) preliminary analysis, (2) formative design evaluation and modification, and (3) design validation. Additional benefits of employing HF principles during medical device development are briefly reviewed, including reduced patient risk by eliminating design flaws, increased patient adherence through the reduction in the complexity of therapeutic regimes, and reduced likelihood for product recalls.

  9. Neurotransmitters act as paracrine signals to regulate insulin secretion from the human pancreatic islet.

    Science.gov (United States)

    Rodriguez-Diaz, Rayner; Menegaz, Danusa; Caicedo, Alejandro

    2014-08-15

    In this symposium review we discuss the role of neurotransmitters as paracrine signals that regulate pancreatic islet function. A large number of neurotransmitters and their receptors has been identified in the islet, but relatively little is known about their involvement in islet biology. Interestingly, neurotransmitters initially thought to be present in autonomic axons innervating the islet are also present in endocrine cells of the human islet. These neurotransmitters can thus be released as paracrine signals to help control hormone release. Here we propose that the role of neurotransmitters may extend beyond controlling endocrine cell function to work as signals modulating vascular flow and immune responses within the islet.

  10. Lifelong Physical Activity Prevents Aging-Associated Insulin Resistance in Human Skeletal Muscle Myotubes via Increased Glucose Transporter Expression

    DEFF Research Database (Denmark)

    Bunprajun, Tipwadee; Henriksen, Tora Ida; Scheele, Camilla

    2013-01-01

    chain protein expression. Interestingly MHCIIa was increased only in myotubes from middle-aged active individuals. Middle-aged sedentary cells had intact insulin-stimulated Akt phosphorylation however, the same cell showed ablated insulin-stimulated glucose uptake and GLUT4 translocation to the plasma...... membrane. On the other hand, middle-aged active cells retained both insulin-stimulated increases in glucose uptake and GLUT4 translocation to the plasma membrane. Middle-aged active cells also had significantly higher mRNA expression of GLUT1 and GLUT4 compared to middle-aged sedentary cells......, and significantly higher GLUT4 protein. It is likely that physical activity induces a number of stable adaptations, including increased GLUT4 expression that are retained in cells ex vivo and protect, or delay the onset of middle-aged-associated insulin resistance. Additionally, a sedentary lifestyle has an impact...

  11. Mitogenic properties of insulin-like growth factors I and II, insulin-like growth factor binding protein-3 and epidermal growth factor on human breast stromal cells in primary culture.

    Science.gov (United States)

    Strange, Karen S; Wilkinson, Darcy; Edin, Glenn; Emerman, Joanne T

    2004-03-01

    Insulin-like growth factors I and II (IGF-I and IGF-II) are growth factors implicated in both normal mammary gland development and breast cancer. We have previously reported on the effects of components of the IGF system on breast epithelial cells. Since data suggests that stromal-epithelial interactions play a crucial role in breast cancer, we have now investigated the mitogenic properties of IGF-I, IGF-II, insulin-like growth factor binding protein-3 (IGFBP-3) and epidermal growth factor (EGF) on human breast stromal cells in primary culture. We show that, under serum-free conditions, stromal cells are stimulated to grow in response to IGF-I and IGF-II in a dose-dependent manner. IGF-I and EGF, a potent stimulator of human breast epithelial cell growth in primary culture and also associated with breast cancer, appear to stimulate stromal cell growth in a synergistic manner. IGFBP-3 does not inhibit the stimulation of growth by IGF-I, or IGF-I plus EGF. However, IGFBP-3 does inhibit the stimulation of growth by IGF-II. In contrast to our previous results with human breast epithelial cells, IGFBP-3 does not have an IGF-independent inhibitory effect on stromal cell growth. This study is the first to address the effects of IGF-I, IGF-II and IGFBP-3 alone and in combination with EGF on human breast stromal cell growth in primary culture. Characterizing the role of the IGF system in both normal breast epithelial cells and stromal cells will aid in our understanding of the mechanisms behind the role of the IGF system in breast cancer.

  12. Model of the Glucose-Insulin-Glucagon Dynamics after Subcutaneous Administration of a Glucagon Rescue Bolus in Healthy Humans

    DEFF Research Database (Denmark)

    Wendt, Sabrina Lyngbye; Møller, Jan Kloppenborg; Haidar, Ahmad;

    In healthy individuals, insulin and glucagon work in a complex fashion to maintain blood glucose levels within a narrow range. This regulation is distorted in patients with diabetes. The hepatic glucose response due to an elevated glucagon level depends on the current insulin concentration and thus......IU/L). The model can be used for simulation of glucagon bolus strategies for treatment of hypoglycemia and for in silico simulation of dual-hormone artificial pancreas algorithms....

  13. 21 CFR 522.1160 - Insulin.

    Science.gov (United States)

    2010-04-01

    ...) Specifications—(1) Each milliliter (mL) of porcine insulin zinc suspension contains 40 international units (IU) of insulin. (2) Each mL of protamine zinc recombinant human insulin suspension contains 40 IU of... clinical signs in dogs with diabetes mellitus. (iii) Limitations. Federal law restricts this drug to use...

  14. Novel covalently linked insulin dimer engineered to investigate the function of insulin dimerization

    DEFF Research Database (Denmark)

    Vinther, Tine N.; Norrman, Mathias; Strauss, Holger M.;

    2012-01-01

    An ingenious system evolved to facilitate insulin binding to the insulin receptor as a monomer and at the same time ensure sufficient stability of insulin during storage. Insulin dimer is the cornerstone of this system. Insulin dimer is relatively weak, which ensures dissociation into monomers...... in the circulation, and it is stabilized by hexamer formation in the presence of zinc ions during storage in the pancreatic ß-cell. Due to the transient nature of insulin dimer, direct investigation of this important form is inherently difficult. To address the relationship between insulin oligomerization...... and insulin stability and function, we engineered a covalently linked insulin dimer in which two monomers were linked by a disulfide bond. The structure of this covalent dimer was identical to the self-association dimer of human insulin. Importantly, this covalent dimer was capable of further oligomerization...

  15. Quantification of adipose tissue insulin sensitivity.

    Science.gov (United States)

    Søndergaard, Esben; Jensen, Michael D

    2016-06-01

    In metabolically healthy humans, adipose tissue is exquisitely sensitive to insulin. Similar to muscle and liver, adipose tissue lipolysis is insulin resistant in adults with central obesity and type 2 diabetes. Perhaps uniquely, however, insulin resistance in adipose tissue may directly contribute to development of insulin resistance in muscle and liver because of the increased delivery of free fatty acids to those tissues. It has been hypothesized that insulin adipose tissue resistance may precede other metabolic defects in obesity and type 2 diabetes. Therefore, precise and reproducible quantification of adipose tissue insulin sensitivity, in vivo, in humans, is an important measure. Unfortunately, no consensus exists on how to determine adipose tissue insulin sensitivity. We review the methods available to quantitate adipose tissue insulin sensitivity and will discuss their strengths and weaknesses.

  16. Insulin receptor what role in breast cancer?

    Science.gov (United States)

    Papa, V; Costantino, A; Belfiore, A

    1997-10-01

    It is commonly believed that the insulin receptor mainly mediates the metabolic effects of insulin, whereas the closely related IGF-I receptor is considered a major factor for the regulation of cell proliferation. Experimental and epidemiological evidence indicates, however, that insulin and insulin receptors may play an important role in breast cancer. This article reviews evidence indicating that (a) insulin receptors are overexpressed in human breast cancer, (b) insulin stimulates growth in breast cancer cells, (c) cells transfected with human insulin receptor may acquire a ligand-dependent transformed phenotype, and (d) breast cancer is associated with insulin resistance and hyperinsulinemia. These findings may open new possibilities in breast cancer prevention, prognosis assessment, and therapy. (Trends Endocrinol Metab 1997; 8:306-312). (c) 1997, Elsevier Science Inc.

  17. Two Cases of Allergy to Insulin in Gestational Diabetes

    Directory of Open Access Journals (Sweden)

    Gi Jun Kim

    2015-09-01

    Full Text Available Allergic reaction to insulin is uncommon since the introduction of human recombinant insulin preparations and is more rare in pregnant than non-pregnant females due to altered immune reaction during pregnancy. Herein, we report two cases of allergic reaction to insulin in gestational diabetes that were successfully managed. One case was a 33-year-old female using isophane-neutral protamine Hagedorn human insulin and insulin lispro. She experienced dyspnea, cough, urticaria and itching sensation at the sites of insulin injection immediately after insulin administration. We discontinued insulin therapy and started oral hypoglycemic agents with metformin and glibenclamide. The other case was a 32-year-old female using insulin lispro and insulin detemer. She experienced pruritus and burning sensation and multiple nodules at the sites of insulin injection. We changed the insulin from insulin lispro to insulin aspart. Assessments including immunoglobulin E (IgE, IgG, eosinophil, insulin antibody level and skin biopsy were performed. In the two cases, the symptoms were resolved after changing the insulin to oral agents or other insulin preparations. We report two cases of allergic reaction to human insulin in gestational diabetes due to its rarity.

  18. Effects of recombinant retroviral vector mediated human insulin like growth factor-1 gene transfection on skeletal muscle growth in rat

    Institute of Scientific and Technical Information of China (English)

    RONG Shu-Ling; LU Yong-Xin; LIAO Yu-Hua; WANG Xiao-Lin; GUO He-Ping; CHANG Chao; GAO Yan-Zhang; MI Shao-Hua; Wan Jian-Ping

    2006-01-01

    Background This study transferred a recombinant gene encoding human insulin like growth factor-1 (hIGF-1)into modified primary skeletal myoblasts with a retroviral vector (pLgXSN) and determined whether the hIGF-1 promoted growth of skeletal muscle in rat.Methods hIGF-lcDNA was amplified in vitro from normal human liver cells by using RT-PCR and cloned into plasmid vector pLgXSN. The recombinant vector pLghIGF-1SN and control vector pLgGFPSN were transfected into packaging cell PT67 and G418 was used to select positive colony. Myoblasts were infected with a high titre viral supernatant and transduction efficiency was evaluated as GFP expression. The expression of hIGF-1 mRNA in myoblasts was investigated by immunocytochemistry and RT-PCR. MTT assays detected the growth of myoblasts in vitro. Myoblasts transduced with pLghIGF-1SN were injected into hind limb muscles of 10-12 week male SD rats. Formed tissues were harvested 4 weeks later. Myocyte diameter, mean weight of hind limb and body were measured to evaluate the skeletal muscle growth.Results Recombinant retroviral plasmid vector pLghIGF-1SN was constructed successfully. The titre of the packaged recombinant retrovirus was 1 × 106 cfu/ml. The transfection rate of PT67 cells reached 100% after G418 screening. hIGF-1 expression was positive in myoblast-IGF-1. The proliferation rate of myoblast-IGF-1 in vitro was higher than GFP-myoblast or myoblast (P< 0.05). The mean weights of hind limb and body of rats injected myoblast-IGF-1 were higher than those of the rats injected with myoblast-GFP or myoblast (P< 0.05). Myocyte diameter had a significant increase in IGF-1 group compared to GFP group and myoblast group (P< 0.05).Conclusions The transfection of the human IGF- 1 gene mediated by a retroviral vector can promote the growth of skeletal muscle in rats. Genetically modified primary skeletal myoblasts provide a possibly effective approach to treat some skeletal muscle diseases.

  19. Biphasic catalysis in water/carbon dioxide micellar systems

    Science.gov (United States)

    Jacobson, Gunilla B.; Tumas, William; Johnston, Keith P.

    2002-01-01

    A process is provided for catalyzing an organic reaction to form a reaction product by placing reactants and a catalyst for the organic reaction, the catalyst of a metal complex and at least one ligand soluble within one of the phases of said aqueous biphasic system, within an aqueous biphasic system including a water phase, a dense phase fluid, and a surfactant adapted for forming an emulsion or microemulsion within the aqueous biphasic system, the reactants soluble within one of the phases of the aqueous biphasic system and convertible in the presence of the catalyst to a product having low solubility in the phase in which the catalyst is soluble; and, maintaining the aqueous biphasic system under pressures, at temperatures, and for a period of time sufficient for the organic reaction to occur and form the reaction product and to maintain sufficient density on the dense phase fluid, the reaction product characterized as having low solubility in the phase in which the catalyst is soluble.

  20. Human Cortical Neural Stem Cells Expressing Insulin-Like Growth Factor-I: A Novel Cellular Therapy for Alzheimer's Disease.

    Science.gov (United States)

    McGinley, Lisa M; Sims, Erika; Lunn, J Simon; Kashlan, Osama N; Chen, Kevin S; Bruno, Elizabeth S; Pacut, Crystal M; Hazel, Tom; Johe, Karl; Sakowski, Stacey A; Feldman, Eva L

    2016-03-01

    Alzheimer's disease (AD) is the most prevalent age-related neurodegenerative disorder and a leading cause of dementia. Current treatment fails to modify underlying disease pathologies and very little progress has been made to develop effective drug treatments. Cellular therapies impact disease by multiple mechanisms, providing increased efficacy compared with traditional single-target approaches. In amyotrophic lateral sclerosis, we have shown that transplanted spinal neural stem cells (NSCs) integrate into the spinal cord, form synapses with the host, improve inflammation, and reduce disease-associated pathologies. Our current goal is to develop a similar "best in class" cellular therapy for AD. Here, we characterize a novel human cortex-derived NSC line modified to express insulin-like growth factor-I (IGF-I), HK532-IGF-I. Because IGF-I promotes neurogenesis and synaptogenesis in vivo, this enhanced NSC line offers additional environmental enrichment, enhanced neuroprotection, and a multifaceted approach to treating complex AD pathologies. We show that autocrine IGF-I production does not impact the cell secretome or normal cellular functions, including proliferation, migration, or maintenance of progenitor status. However, HK532-IGF-I cells preferentially differentiate into gamma-aminobutyric acid-ergic neurons, a subtype dysregulated in AD; produce increased vascular endothelial growth factor levels; and display an increased neuroprotective capacity in vitro. We also demonstrate that HK532-IGF-I cells survive peri-hippocampal transplantation in a murine AD model and exhibit long-term persistence in targeted brain areas. In conclusion, we believe that harnessing the benefits of cellular and IGF-I therapies together will provide the optimal therapeutic benefit to patients, and our findings support further preclinical development of HK532-IGF-I cells into a disease-modifying intervention for AD.

  1. The human leukocyte antigen genotype has a modest effect on the insulin gene polymorphism-associated susceptibility to type 1 diabetes in the Finnish population.

    Science.gov (United States)

    Laine, A P; Hermann, R; Knip, M; Simell, O; Akerblom, H K; Ilonen, J

    2004-01-01

    In addition to the known human leukocyte antigen (HLA)-associated risk, polymorphisms of insulin gene region show association with type 1 diabetes. We analyzed possible interactions between the HLA class II genotypes and -2221 MspI (insulin) INS gene polymorphism in Finnish population, using a series of 1331 diabetic children and 2222 healthy newborns. C/C genotype was increased among diabetic children compared to the controls (83.2 vs 70.1%). This genotype was slightly more common in diabetic children with low or moderate HLA-associated risk than in those with high risk, but INS gene effect was clear in all major HLA-risk genotypes and, thus, can be used as an additional risk prediction marker, irrespective of HLA genotypes.

  2. Le medicament du mois. Insuline glargine (Lantus).

    OpenAIRE

    Scheen, André

    2004-01-01

    Insulin glargine (Lantus) is a human insulin analogue produced by recombinant DNA technology and recently launched by Aventis. Modification of the human insulin molecule at position A21 and at the C-terminus of the B-chain results in the formation of a stable compound that is soluble at pH 4.0, but forms amorphous microprecipitates in subcutaneous tissue (pH > 7,4) from which small amounts of insulin glargine are gradually released. The plasma concentration versus time profile of insulin glar...

  3. Extracellular matrix gel is necessary for in vitro cultivation of insulin producing cells from human umbilical cord blood derived mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    GAO Feng; WU De-quan; HU Yan-hua; JIN Guang-xin

    2008-01-01

    Background Pancreatic islet cell transplantation is an effective approach to treat type 1 diabetes. However, this therapy is not widely used because of the severe shortage of transplantable donor islets. This study investigated whether mesenchymal stem cells (MSCs) derived from human umbilical cord blood (UCB) could be transdifferentiated into insulin producing cells in vitro and the role of extracellular matrix (ECM) gel in this procedure.Methods Human UCB samples were collected and MSCs were isolated. MSCs specific marker proteins were analyzed by a flow cytometer. The capacities of osteoblast and adipocyte to differentiate were tested. Differentiation into islet like cell was induced by a 15-day protocol with or without ECM gel. Pancreatic characteristics were evaluated with immunofluorescence, reverse transcription polymerase chain reaction (RT-PCR) and flow cytometry. Insulin content and release in response to glucose stimulation were detected with chemiluminescent immunoassay system.Results Sixteen MSCs were isolated from 42 term human UCB units (38%). Human UCB-MSCs expressed MSCs specific markers and could be induced in vitro into osteoblast and adipocyte. Islet like cell clusters appeared about 9 days after pancreatic differentiation in the inducing system with ECM gel. The insulin positive cells accounted for (25.2±3.4)% of the induced cells. The induced cells expressed islet related genes and hormones, but were not very responsive to glucose challenge. When MSCs were induced without ECM gel, clusters formation and secretion of functional islet proteins could not be observed.Conclusions Human UCB-MSCs can differentiate into islet like cells in vitro and ECM gel plays an important role in pancreatic endocrine cell maturation and formation of three dimensional structures.

  4. Notch signaling: a novel regulating differentiation mechanism of human umbilical cord blood-derived mesenchymal stem cells into insulin-producing cells in vitro

    Institute of Scientific and Technical Information of China (English)

    HU Yan-hua; WU De-quan; GAO Feng; LI Guo-dong; ZHANG Xin-chen

    2010-01-01

    Background Human umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) could be induced to differentiate into insulin producing cells (IPCs) in vitro, which have good application potential in the cell replacement treatment of type-1 diabetes. However, the mechanisms regulating this differentiation have remained largely unknown. Notch signaling is critical in cell differentiation. This study investigated whether Notch signaling could regulate the IPCs differentiation of human UCB-MSCs. Methods Using an interfering Notch signaling protocol in vitro, we studied the role of Notch signaling in differentiation of human UCB-MSCs into IPCs. In a control group the induction took place without interfering Notch signaling. Results Human UCB-MSCs expressed the genes of Notch receptors (Notch 1 and Notch 2) and ligands (Jagged 1 and Deltalike 1). Human UCB-MSCs with over-expressing Notch signaling in differentiation resulted in the down-regulation of insulin gene level, proinsulin protein expression, and insulin-positive cells percentage compared with the control group. These results showed that over-expressing Notch signaling inhibited IPCs differentiation. Conversely, when Notch signaling was attenuated by receptor inhibitor, the induced cells increased on average by 3.06-fold (n=4, P<0.001) in insulin gene level, 2.60-fold (n=3, P <0.02) in proinsulin protein expression, and 1.62-fold (n=6, P <0.001) in the rate of IPCs compared with the control group. Notch signaling inhibition significantly promoted IPCs differentiation with about 40% of human UCB-MSCs that converted to IPCs, but these IPCs were not responsive to glucose challenge very well both in vitro and in vivo. Hence, further research has to be carried out in the future. Conclusions Notch signaling may be an important mechanism regulating IPCs differentiation of human UCB-MSCs in vitro and Notch signaling inhibition may be an efficient way to increase the number of IPCs, which may resolve the shortage of

  5. The Placental Variant of Human Growth Hormone Reduces Maternal Insulin Sensitivity in a Dose-Dependent Manner in C57BL/6J Mice.

    Science.gov (United States)

    Liao, Shutan; Vickers, Mark H; Stanley, Joanna L; Ponnampalam, Anna P; Baker, Philip N; Perry, Jo K

    2016-03-01

    The human placental GH variant (GH-V) is secreted continuously from the syncytiotrophoblast layer of the placenta during pregnancy and is thought to play a key role in the maternal adaptation to pregnancy. Maternal GH-V concentrations are closely related to fetal growth in humans. GH-V has also been proposed as a potential candidate to mediate insulin resistance observed later in pregnancy. To determine the effect of maternal GH-V administration on maternal and fetal growth and metabolic outcomes during pregnancy, we examined the dose-response relationship for GH-V administration in a mouse model of normal pregnancy. Pregnant C57BL/6J mice were randomized to receive vehicle or GH-V (0.25, 1, 2, or 5 mg/kg · d) by osmotic pump from gestational days 12.5 to 18.5. Fetal linear growth was slightly reduced in the 5 mg/kg dose compared with vehicle and the 0.25 mg/kg groups, respectively, whereas placental weight was not affected. GH-V treatment did not affect maternal body weights or food intake. However, treatment with 5 mg/kg · d significantly increased maternal fasting plasma insulin concentrations with impaired insulin sensitivity observed at day 18.5 as assessed by homeostasis model assessment. At 5 mg/kg · d, there was also an increase in maternal hepatic GH receptor/binding protein (Ghr/Ghbp) and IGF binding protein 3 (Igfbp3) mRNA levels, but GH-V did not alter maternal plasma IGF-1 concentrations or hepatic Igf-1 mRNA expression. Our findings suggest that at higher doses, GH-V treatment can cause hyperinsulinemia and is a likely mediator of the insulin resistance associated with late pregnancy.

  6. Progress on the biphase turbine at Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Cerini, D.; Hays, L.; Studhalter, W. [Douglas Energy Company, Placentia, CA (United States)

    1997-12-31

    The status of a Biphase turbine power plant being installed at the Cerro Prieto geothermal field is presented. The major modules for the power plant are completed except for a back pressure steam turbine. The power plant will be started in April 1997 with the Biphase turbine alone followed by the addition of the steam turbine module two months later. The current power plant performance level is 2780 kWe due to a decline in the well. An increase in power output to 4060 kWe by adding the flow from another well is planned. The addition of five Biphase power plants with a total power output of 21.2 megawatts is described.

  7. Molecular biocoding of insulin

    Directory of Open Access Journals (Sweden)

    Lutvo Kuric

    2010-07-01

    Full Text Available Lutvo KuricNovi Travnik, Kalinska, Bosnia and Herzegovina Abstract: This paper discusses cyberinformation studies of the amino acid composition of insulin, in particular the identification of scientific terminology that could describe this phenomenon, ie, the study of genetic information, as well as the relationship between the genetic language of proteins and theoretical aspects of this system and cybernetics. The results of this research show that there is a matrix code for insulin. It also shows that the coding system within the amino acid language gives detailed information, not only on the amino acid “record”, but also on its structure, configuration, and various shapes. The issue of the existence of an insulin code and coding of the individual structural elements of this protein are discussed. Answers to the following questions are sought. Does the matrix mechanism for biosynthesis of this protein function within the law of the general theory of information systems, and what is the significance of this for understanding the genetic language of insulin? What is the essence of existence and functioning of this language? Is the genetic information characterized only by biochemical principles or it is also characterized by cyberinformation principles? The potential effects of physical and chemical, as well as cybernetic and information principles, on the biochemical basis of insulin are also investigated. This paper discusses new methods for developing genetic technologies, in particular more advanced digital technology based on programming, cybernetics, and informational laws and systems, and how this new technology could be useful in medicine, bioinformatics, genetics, biochemistry, and other natural sciences.Keywords: human insulin, insulin model, biocode, genetic code, amino acids

  8. Anti-insulin antibody test

    Science.gov (United States)

    Insulin antibodies - serum; Insulin Ab test; Insulin resistance - insulin antibodies; Diabetes - insulin antibodies ... You appear to have an allergic response to insulin Insulin no longer seems to control your diabetes

  9. Receptor binding characteristics and cytotoxicity of insulin-methotrexate

    Institute of Scientific and Technical Information of China (English)

    Xiao-Hong Ou; An-Ren Kuang; Zheng-Lu Liang; Xian Peng; Yu-Guo Zhong

    2004-01-01

    AIM: To characterize the receptor binding affinity and cytotoxicity of insulin-methotrexate (MTX) for the potential utilization of insulin as carriers for carcinoma target drugs.METHODS: MTX was covalently linked to insulin. InsulinMTX conjugate was purified by Sephadex G-25 column and analyzed by high performance liquid chromatography.Hepatocellular carcinoma cell membrane fractions were isolated by sucrose density gradient centrifugation.Competitive displacement of 125I-insulin with insulin and insulin-MTX binding to insulin receptors were carried out.Cytoreductive effect of insulin-MTX on human hepatoma BEL7402 cells and human hepatocyte cell line HL7702 was evaluated using the MTT assay.RESULTS: Insulin-MTX competed as effectively as insulin with 125I-insulin for insulin receptors. The values of Kd for insulin-MTX and insulin were 93.82±19.32 nmol/L and 5.01±1.24 nmol/L, respectively. The value of Kd for insulinMTX was significantly increased in comparison with insulin (t=7.2532,n=4, P<0.005). Insulin-MTX inhibited the growth of human hepatoma cells (BEL7402) almost as potently as MTX. The inhibitory effect reached a peak on the 5 th day when the growth of cells was inhibited by 79% at a concentration of 5.0 μg/mL insulin-MTX. Treatment with 5.0 μg/mL of MTX and 5.0 μg/mL of insulin-MTX merely resulted in inhibition of HL7702 cells by 31.5% and 7.8%on the 5 th day.CONCLUSION: Insulin-MTX specifically recognizes insulin receptors and inhibits the growth of BEL7402 cells. These results suggest that insulin can be used as a carrier in receptor mediated carcinoma-targeting therapy.

  10. The transcriptional response in human umbilical vein endothelial cells exposed to insulin: a dynamic gene expression approach.

    Directory of Open Access Journals (Sweden)

    Barbara Di Camillo

    Full Text Available BACKGROUND: In diabetes chronic hyperinsulinemia contributes to the instability of the atherosclerotic plaque and stimulates cellular proliferation through the activation of the MAP kinases, which in turn regulate cellular proliferation. However, it is not known whether insulin itself could increase the transcription of specific genes for cellular proliferation in the endothelium. Hence, the characterization of transcriptional modifications in endothelium is an important step for a better understanding of the mechanism of insulin action and the relationship between endothelial cell dysfunction and insulin resistance. METHODOLOGY AND PRINCIPAL FINDINGS: The transcriptional response of endothelial cells in the 440 minutes following insulin stimulation was monitored using microarrays and compared to a control condition. About 1700 genes were selected as differentially expressed based on their treated minus control profile, thus allowing the detection of even small but systematic changes in gene expression. Genes were clustered in 7 groups according to their time expression profile and classified into 15 functional categories that can support the biological effects of insulin, based on Gene Ontology enrichment analysis. In terms of endothelial function, the most prominent processes affected were NADH dehydrogenase activity, N-terminal myristoylation domain binding, nitric-oxide synthase regulator activity and growth factor binding. Pathway-based enrichment analysis revealed "Electron Transport Chain" significantly enriched. Results were validated on genes belonging to "Electron Transport Chain" pathway, using quantitative RT-PCR. CONCLUSIONS: As far as we know, this is the first systematic study in the literature monitoring transcriptional response to insulin in endothelial cells, in a time series microarray experiment. Since chronic hyperinsulinemia contributes to the instability of the atherosclerotic plaque and stimulates cellular proliferation

  11. Biphasic Malignant Pleural Mesothelioma Masquerading as a Primary Skeletal Tumor

    Science.gov (United States)

    Diacovo, Maria Julia

    2016-01-01

    Biphasic malignant pleural mesothelioma is a rare malignant tumor, usually presenting as a pleural-based mass in a patient with history of chronic asbestos exposure. We herein report a case of a 41-year-old man who presented with chest pain and had a chest computed tomography (CT) scan suggestive of a primary skeletal tumor originating from the ribs (chondrosarcoma or osteosarcoma), with no history of asbestos exposure. CT-guided core needle biopsies were diagnosed as malignant sarcomatoid mesothelioma. Surgical resection and chest wall reconstruction were performed, confirming the diagnosis and revealing a secondary histologic component (epithelioid), supporting the diagnosis of biphasic malignant mesothelioma. PMID:27660729

  12. Biphasic Malignant Pleural Mesothelioma Masquerading as a Primary Skeletal Tumor

    Directory of Open Access Journals (Sweden)

    James Benjamin Gleason

    2016-01-01

    Full Text Available Biphasic malignant pleural mesothelioma is a rare malignant tumor, usually presenting as a pleural-based mass in a patient with history of chronic asbestos exposure. We herein report a case of a 41-year-old man who presented with chest pain and had a chest computed tomography (CT scan suggestive of a primary skeletal tumor originating from the ribs (chondrosarcoma or osteosarcoma, with no history of asbestos exposure. CT-guided core needle biopsies were diagnosed as malignant sarcomatoid mesothelioma. Surgical resection and chest wall reconstruction were performed, confirming the diagnosis and revealing a secondary histologic component (epithelioid, supporting the diagnosis of biphasic malignant mesothelioma.

  13. Acute exercise and physiological insulin induce distinct phosphorylation signatures on TBC1D1 and TBC1D4 in human skeletal muscle

    DEFF Research Database (Denmark)

    Treebak, Jonas Thue; Pehmøller, Christian; Kristensen, Jonas Møller

    2014-01-01

    We investigated the phosphorylation signatures of two Rab GTPase activating proteins TBC1D1 and TBC1D4 in human skeletal muscle in response to physical exercise and physiological insulin levels induced by a carbohydrate rich meal using a paired experimental design. Eight healthy male volunteers...... in response to physiological stimuli in human skeletal muscle and support the idea that Akt and AMPK are upstream kinases. TBC1D1 phosphorylation signatures were comparable between in vitro contracted mouse skeletal muscle and exercised human muscle, and we show that AMPK was regulating phosphorylation...... of these sites in mouse muscle. Contraction and exercise elicited a different phosphorylation pattern of TBC1D4 in mouse compared with human muscle, and although different circumstances in our experimental setup may contribute to this difference, the observation exemplifies that transferring findings between...

  14. Munc18b Increases Insulin Granule Fusion, Restoring Deficient Insulin Secretion in Type-2 Diabetes Human and Goto-Kakizaki Rat Islets with Improvement in Glucose Homeostasis

    Directory of Open Access Journals (Sweden)

    Tairan Qin

    2017-02-01

    Infusion of Ad-Munc18b into GK rat pancreas led to sustained improvement in glucose homeostasis. However, Munc18b overexpression in normal islets increased only newcomer SG fusion. Therefore, Munc18b could potentially be deployed in human T2D to rescue the deficient GSIS.

  15. Insulin therapy and quality of life. A review

    DEFF Research Database (Denmark)

    Pouwer, Francois; Hermanns, Norbert

    2009-01-01

    Three central goals in the treatment of diabetes mellitus are (1) the avoidance of hyperglycaemia to prevent the development or progression of diabetes complications over time, (2) the avoidance of hypoglycaemia and (3) the maintenance or achievement of good quality of life. Insulin is the most...... powerful agent that can be used to control blood glucose levels. This article reviews the studies that have investigated the effects of different types of insulin and insulin delivery techniques on quality of life of patients with type 1 or type 2 diabetes. First, the concept of 'quality of life' (Qo......-acting insulin analogues or biphasic mixtures; (3) multiple daily injections versus pump therapy. Having multiple complications of diabetes is clearly associated with decreased QoL. Results from large studies such as the Diabetes Control and Complications Trial (DCCT) and United Kingdom Prospective Diabetes...

  16. Apigenin modulates the expression levels of pro-inflammatory mediators to reduce the human insulin amyloid-induced oxidant damages in SK-N-MC cells.

    Science.gov (United States)

    Amini, R; Yazdanparast, R; Ghaffari, S H

    2015-06-01

    Amyloid depositions of proteins play crucial roles in a wide variety of degenerative disorders called amyloidosis. Although the exact mechanisms involved in amyloid-mediated cytotoxicity remain unknown, increased formation of reactive oxygen species (ROS) and nitrogen species and overproduction of pro-inflammatory cytokines are believed to play key roles in the process. In that regard, we investigated the effect of apigenin, a common dietary flavonoid with high antioxidant and anti-inflammatory properties on potential factors involved in cytotoxicity of human insulin amyloids. Pretreatment of SK-N-MC neuroblastoma cells with apigenin increased cell viability and reduced the apoptosis induced by insulin fibrils. In addition, apigenin attenuated insulin fibril-induced ROS production and lipid peroxidation. Our result also demonstrated that pretreatment of the fibril-affected cells with apigenin caused an increase in catalase activity and the intracellular glutathione content along with reduction in nitric oxide production and nuclear factor κB, tumor necrosis factor α, and interleukin 6 gene expression based on real-time polymerase chain reaction evaluation. In accordance with these results, apigenin could be a promising candidate in the design of natural-based drugs for treatment or prevention of amyloid-related disorders.

  17. Sustained Brown Fat Stimulation and Insulin Sensitization by a Humanized Bispecific Antibody Agonist for Fibroblast Growth Factor Receptor 1/βKlotho Complex

    Directory of Open Access Journals (Sweden)

    Ganesh Kolumam

    2015-07-01

    Full Text Available Dissipating excess calories as heat through therapeutic stimulation of brown adipose tissues (BAT has been proposed as a potential treatment for obesity-linked disorders. Here, we describe the generation of a humanized effector-less bispecific antibody that activates fibroblast growth factor receptor (FGFR 1/βKlotho complex, a common receptor for FGF21 and FGF19. Using this molecule, we show that antibody-mediated activation of FGFR1/βKlotho complex in mice induces sustained energy expenditure in BAT, browning of white adipose tissue, weight loss, and improvements in obesity-associated metabolic derangements including insulin resistance, hyperglycemia, dyslipidemia and hepatosteatosis. In mice and cynomolgus monkeys, FGFR1/βKlotho activation increased serum high-molecular-weight adiponectin, which appears to contribute over time by enhancing the amplitude of the metabolic benefits. At the same time, insulin sensitization by FGFR1/βKlotho activation occurs even before the onset of weight loss in a manner that is independent of adiponectin. Together, selective activation of FGFR1/βKlotho complex with a long acting therapeutic antibody represents an attractive approach for the treatment of type 2 diabetes and other obesity-linked disorders through enhanced energy expenditure, insulin sensitization and induction of high-molecular-weight adiponectin.

  18. Effects of Probiotics and Synbiotics on Obesity, Insulin Resistance Syndrome, Type 2 Diabetes and Non-Alcoholic Fatty Liver Disease: A Review of Human Clinical Trials.

    Science.gov (United States)

    Sáez-Lara, Maria Jose; Robles-Sanchez, Candido; Ruiz-Ojeda, Francisco Javier; Plaza-Diaz, Julio; Gil, Angel

    2016-06-13

    The use of probiotics and synbiotics in the prevention and treatment of different disorders has dramatically increased over the last decade. Both probiotics and synbiotics are well known ingredients of functional foods and nutraceuticals and may provide beneficial health effects because they can influence the intestinal microbial ecology and immunity. The present study reviews the effects of probiotics and synbiotics on obesity, insulin resistance syndrome (IRS), type 2 diabetes (T2D) and non-alcoholic fatty liver disease (NAFLD) in human randomized clinical trials. Select probiotics and synbiotics provided beneficial effects in patients with obesity, mainly affecting the body mass index and fat mass. Some probiotics had beneficial effects on IRS, decreasing the cell adhesion molecule-1 levels, and the synbiotics decreased the insulin resistance and plasma lipid levels. Moreover, select probiotics improved the carbohydrate metabolism, fasting blood glucose, insulin sensitivity and antioxidant status and also reduced metabolic stress in subjects with T2D. Some probiotics and synbiotics improved the liver and metabolic parameters in patients with NAFLD. The oral intake of probiotics and synbiotics as co-adjuvants for the prevention and treatment of obesity, IRS, T2D and NAFLD is partially supported by the data shown in the present review. However, further studies are required to understand the precise mechanism of how probiotics and synbiotics affect these metabolic disorders.

  19. Effects of Probiotics and Synbiotics on Obesity, Insulin Resistance Syndrome, Type 2 Diabetes and Non-Alcoholic Fatty Liver Disease: A Review of Human Clinical Trials

    Directory of Open Access Journals (Sweden)

    Maria Jose Sáez-Lara

    2016-06-01

    Full Text Available The use of probiotics and synbiotics in the prevention and treatment of different disorders has dramatically increased over the last decade. Both probiotics and synbiotics are well known ingredients of functional foods and nutraceuticals and may provide beneficial health effects because they can influence the intestinal microbial ecology and immunity. The present study reviews the effects of probiotics and synbiotics on obesity, insulin resistance syndrome (IRS, type 2 diabetes (T2D and non-alcoholic fatty liver disease (NAFLD in human randomized clinical trials. Select probiotics and synbiotics provided beneficial effects in patients with obesity, mainly affecting the body mass index and fat mass. Some probiotics had beneficial effects on IRS, decreasing the cell adhesion molecule-1 levels, and the synbiotics decreased the insulin resistance and plasma lipid levels. Moreover, select probiotics improved the carbohydrate metabolism, fasting blood glucose, insulin sensitivity and antioxidant status and also reduced metabolic stress in subjects with T2D. Some probiotics and synbiotics improved the liver and metabolic parameters in patients with NAFLD. The oral intake of probiotics and synbiotics as co-adjuvants for the prevention and treatment of obesity, IRS, T2D and NAFLD is partially supported by the data shown in the present review. However, further studies are required to understand the precise mechanism of how probiotics and synbiotics affect these metabolic disorders.

  20. Effects of Probiotics and Synbiotics on Obesity, Insulin Resistance Syndrome, Type 2 Diabetes and Non-Alcoholic Fatty Liver Disease: A Review of Human Clinical Trials

    Science.gov (United States)

    Sáez-Lara, Maria Jose; Robles-Sanchez, Candido; Ruiz-Ojeda, Francisco Javier; Plaza-Diaz, Julio; Gil, Angel

    2016-01-01

    The use of probiotics and synbiotics in the prevention and treatment of different disorders has dramatically increased over the last decade. Both probiotics and synbiotics are well known ingredients of functional foods and nutraceuticals and may provide beneficial health effects because they can influence the intestinal microbial ecology and immunity. The present study reviews the effects of probiotics and synbiotics on obesity, insulin resistance syndrome (IRS), type 2 diabetes (T2D) and non-alcoholic fatty liver disease (NAFLD) in human randomized clinical trials. Select probiotics and synbiotics provided beneficial effects in patients with obesity, mainly affecting the body mass index and fat mass. Some probiotics had beneficial effects on IRS, decreasing the cell adhesion molecule-1 levels, and the synbiotics decreased the insulin resistance and plasma lipid levels. Moreover, select probiotics improved the carbohydrate metabolism, fasting blood glucose, insulin sensitivity and antioxidant status and also reduced metabolic stress in subjects with T2D. Some probiotics and synbiotics improved the liver and metabolic parameters in patients with NAFLD. The oral intake of probiotics and synbiotics as co-adjuvants for the prevention and treatment of obesity, IRS, T2D and NAFLD is partially supported by the data shown in the present review. However, further studies are required to understand the precise mechanism of how probiotics and synbiotics affect these metabolic disorders. PMID:27304953

  1. Direct effects of TNF-α on local fuel metabolism and cytokine levels in the placebo controlled bilaterally infused human leg; increased insulin sensitivity, increased net protein breakdown and increased IL-6 release

    DEFF Research Database (Denmark)

    Bach, Ermina; Nielsen, Bent Roni Ranghøj; Vendelbo, Mikkel H;

    2013-01-01

    Tumor necrosis factor-α (TNF-α) has widespread metabolic actions. Systemic TNF-α administration, however, generates a complex hormonal and metabolic response. Our study was designed to test whether regional, placebo-controlled TNF-α infusion directly affects insulin resistance and protein breakdo...... interest and may concurrently act to provide adequate tissue fuel supply and contribute to the occurrence of systemic hypoglycemia. This distinct metabolic feature places TNF-α among the rare insulin mimetics of human origin....

  2. Novel covalently linked insulin dimer engineered to investigate the function of insulin dimerization

    DEFF Research Database (Denmark)

    Vinther, Tine N.; Norrman, Mathias; Strauss, Holger M.;

    2012-01-01

    and insulin stability and function, we engineered a covalently linked insulin dimer in which two monomers were linked by a disulfide bond. The structure of this covalent dimer was identical to the self-association dimer of human insulin. Importantly, this covalent dimer was capable of further oligomerization...... to form the structural equivalent of the classical hexamer. The covalently linked dimer neither bound to the insulin receptor, nor induced a metabolic response in vitro. However, it was extremely thermodynamically stable and did not form amyloid fibrils when subjected to mechanical stress, underlining......An ingenious system evolved to facilitate insulin binding to the insulin receptor as a monomer and at the same time ensure sufficient stability of insulin during storage. Insulin dimer is the cornerstone of this system. Insulin dimer is relatively weak, which ensures dissociation into monomers...

  3. Determination of free insulin-like growth factor-I in human serum: comparison of ultrafiltration and direct immunoradiometric assay

    DEFF Research Database (Denmark)

    Frystyk, J; Ivarsen, P; Støving, R K;

    2001-01-01

    Two fundamentally different methods are currently used for the determination of free insulin-like growth factor-I (IGF-I): ultrafiltration by centrifugation (UF) and direct immunoradiometric assay (IRMA). The aim was to evaluate a commercial IRMA (DSL, Webster, TX, USA) and to compare it with UF....

  4. Acute administration of unacylated ghrelin has no effect on Basal or stimulated insulin secretion in healthy humans.

    Science.gov (United States)

    Tong, Jenny; Davis, Harold W; Summer, Suzanne; Benoit, Stephen C; Haque, Ahrar; Bidlingmaier, Martin; Tschöp, Matthias H; D'Alessio, David

    2014-07-01

    Unacylated ghrelin (UAG) is the predominant ghrelin isoform in the circulation. Despite its inability to activate the classical ghrelin receptor, preclinical studies suggest that UAG may promote β-cell function. We hypothesized that UAG would oppose the effects of acylated ghrelin (AG) on insulin secretion and glucose tolerance. AG (1 µg/kg/h), UAG (4 µg/kg/h), combined AG+UAG, or saline were infused to 17 healthy subjects (9 men and 8 women) on four occasions in randomized order. Ghrelin was infused for 30 min to achieve steady-state levels and continued through a 3-h intravenous glucose tolerance test. The acute insulin response to glucose (AIRg), insulin sensitivity index (SI), disposition index (DI), and intravenous glucose tolerance (kg) were compared for each subject during the four infusions. AG infusion raised fasting glucose levels but had no effect on fasting plasma insulin. Compared with the saline control, AG and AG+UAG both decreased AIRg, but UAG alone had no effect. SI did not differ among the treatments. AG, but not UAG, reduced DI and kg and increased plasma growth hormone. UAG did not alter growth hormone, cortisol, glucagon, or free fatty acid levels. UAG selectively decreased glucose and fructose consumption compared with the other treatments. In contrast to previous reports, acute administration of UAG does not have independent effects on glucose tolerance or β-cell function and neither augments nor antagonizes the effects of AG.

  5. Fibronectin and laminin promote differentiation of human mesenchymal stem cells into insulin producing cells through activating Akt and ERK

    Directory of Open Access Journals (Sweden)

    Chiou Shih-Hwa

    2010-07-01

    Full Text Available Abstract Background Islet transplantation provides a promising cure for Type 1 diabetes; however it is limited by a shortage of pancreas donors. Bone marrow-derived multipotent mesenchymal stem cells (MSCs offer renewable cells for generating insulin-producing cells (IPCs. Methods We used a four-stage differentiation protocol, containing neuronal differentiation and IPC-conversion stages, and combined with pellet suspension culture to induce IPC differentiation. Results Here, we report adding extracellular matrix proteins (ECM such as fibronectin (FN or laminin (LAM enhances pancreatic differentiation with increases in insulin and Glut2 gene expressions, proinsulin and insulin protein levels, and insulin release in response to elevated glucose concentration. Adding FN or LAM induced activation of Akt and ERK. Blocking Akt or ERK by adding LY294002 (PI3K specific inhibitor, PD98059 (MEK specific inhibitor or knocking down Akt or ERK failed to abrogate FN or LAM-induced enhancement of IPC differentiation. Only blocking both of Akt and ERK or knocking down Akt and ERK inhibited the enhancement of IPC differentiation by adding ECM. Conclusions These data prove IPC differentiation by MSCs can be modulated by adding ECM, and these stimulatory effects were mediated through activation of Akt and ERK pathways.

  6. Do nutrient-gut-microbiota interactions play a role in human obesity, insulin resistance and type 2 diabetes?

    NARCIS (Netherlands)

    Diamant, M.; Vaughan, E.E.; Vos, de W.M.

    2011-01-01

    The current obesity and type 2 diabetes pandemics have causes beyond changes in eating and exercise habits against a susceptible genetic background. Gut bacteria seem to additionally contribute to the differences in body weight, fat distribution, insulin sensitivity and glucose- and lipid-metabolism

  7. A novel syndrome of autosomal-dominant hyperinsulinemic hypoglycemia linked to a mutation in the human insulin receptor gene

    DEFF Research Database (Denmark)

    Højlund, Kurt; Hansen, Torben; Lajer, Maria

    2004-01-01

    a missense mutation (Arg1174Gln) in the tyrosine kinase domain of the insulin receptor gene that cosegregated with the disease phenotype (logarithm of odds [LOD] score 3.21). In conclusion, we report a novel syndrome of autosomal-dominant hyperinsulinemic hypoglycemia. The findings demonstrate...

  8. Diabetes and Insulin

    Science.gov (United States)

    ... in the abdomen just behind the stomach, produces insulin. Insulin is a hormone that takes glucose from the ... occurs when the pancreas does not produce enough insulin or when the body doesn’t use insulin ...

  9. Insulin-responsiveness of tumor growth.

    Science.gov (United States)

    Chantelau, Ernst

    2009-05-01

    In October 2008, the 2nd International Insulin & Cancer Workshop convened roughly 30 researchers from eight countries in Düsseldorf/Germany. At this meeting, which was industry-independent like the preceding one in 2007, the following issues were discussed a) association between certain cancers and endogenous insulin production in humans, b) growth-promoting effects of insulin in animal experiments, c) mitogenic and anti-apoptotic activity of pharmaceutic insulin and insulin analogues in in vitro experiments, d) potential mechanisms of insulin action on cell growth, mediated by IGF-1 receptor and insulin receptor signaling, and e) IGF-1 receptor targeting for inhibition of tumor growth. It was concluded that further research is necessary to elucidate the clinical effects of these observations, and their potential for human neoplastic disease and treatment.

  10. Evaluation of the maximum beyond-use-date stability of regular human insulin extemporaneously prepared in 0.9% sodium chloride in a polyvinyl chloride bag

    OpenAIRE

    Rocchio MA; Belisle CD; Greenwood BC; Cotugno MC; Szumita PM

    2013-01-01

    Megan A Rocchio, Caryn D Belisle, Bonnie C Greenwood, Michael C Cotugno, Paul M SzumitaDepartment of Pharmacy, Brigham and Women's Hospital, Boston, MA, USABackground: Regular human insulin 100 units added to a sufficient quantity of 0.9% sodium chloride, to yield a total volume of 100 mL within a polyvinylchloride bag, is accepted to be stable for 24 hours due to physical denaturation and chemical modification. The objective of this study was to evaluate the extended stability of suc...

  11. Correction of Murine Diabetic Hyperglycaemia With A Single Systemic Administration of An AAV2/8 Vector Containing A Novel Codon Optimized Human Insulin Gene.

    Science.gov (United States)

    Gan, Shu Uin; Notaridou, Maria; Fu, Zhen Ying; Lee, Kok Onn; Sia, Kian Chuan; Nathwani, Amit Chunilal; Della Peruta, Marco; Calne, Roy Yorke

    2016-01-01

    We report the correction of hyperglycemia of STZ induced diabetic mice using one intravenous systemic administration of a single stranded serotype 8 pseudotyped adeno-associated virus (ssAAV2/8) vector encoding the human proinsulin gene under a constitutive liver specific promoter. In vivo dose titration experiments were carried out and we identified an optimal range that achieved maintenance of euglycaemia or a mild diabetic condition for at least 9 months and ongoing to beyond 1 year for some animals, accompanied by human C-peptide secretion and weight gain. Further DNA codon optimization of the insulin gene construct resulted in approximately 3-10 times more human C-peptide secreted in the blood of codon optimized treated animals thereby reducing the number of vector particles required to achieve the same extent of reduction in blood glucose levels as the non-codon optimized vector. The constitutive secretion of insulin achieved with a single administration of the vector could be of therapeutic value for some diabetic patients.

  12. Excess exposure to insulin is the primary cause of insulin resistance and its associated atherosclerosis.

    Science.gov (United States)

    Cao, Wenhong; Ning, Jie; Yang, Xuefeng; Liu, Zhenqi

    2011-11-01

    The main goal of this review is to provide more specific and effective targets for prevention and treatment of insulin resistance and associated atherosclerosis. Modern technologies and medicine have vastly improved human health and prolonged the average life span of humans primarily by eliminating various premature deaths and infectious diseases. The modern technologies have also provided us abundant food and convenient transportation tools such as cars. As a result, more people are becoming overfed and sedentary. People are generally ingesting more calories than their bodies' need, leading to the so-called "positive energy imbalance", which is inseparable from the development of insulin resistance and its associated atherosclerosis. A direct consequence of insulin resistance is hyperinsulinemia. The current general view is that insulin is not functional properly in the presence of insulin resistance. Thus, the role of insulin itself in the development of insulin resistance and associated atherosclerosis has not been recognized. We have recently observed that the basal level of insulin signaling is increased in the presence of insulin resistance and hyperinsulinemia. In this review, we will explain how the increased basal insulin signaling contributes to the development of insulin resistance and associated atherosclerosis. We will first explain how insulin causes insulin resistance through two arbitrary stages (before and after the presence of obvious insulin resistance), and, then, explain how the excess exposure to insulin and the relative insulin insufficiency contributes to the atherosclerotic diseases. We propose that blockade of the excess insulin signaling is a viable approach to prevent and/or reverse insulin resistance and its associated atherosclerosis.

  13. A docking study of insulin with LI-CR-L2 ecto domain of insulin receptor: an easy way for preliminary screening of novel anti-diabetic peptides

    OpenAIRE

    Bhattacharyya, Rajasri; Banerjee, Dibyajyoti

    2012-01-01

    Although interaction of human insulin with its receptor is studied to considerable extent such studies are currently lacking with recombinant insulin in-spite of its rampant clinical use. It is known that at molecular level the interaction of recombinant insulin with insulin receptor is similar to human insulin but not exactly same. With the increasing incidence of diabetes throughout the globe use of recombinant insulin is also increasing at a considerable rate. Therefore it is need of the h...

  14. Parallel-to-serial biphase-data converter

    Science.gov (United States)

    Truelove, R. D.

    1968-01-01

    Data converter produces a serial biphase output signal from parallel input data. Alternate bits are loaded into a shift register in complement form so that the bits appear at the end of the shift register in a true-complement form sequence.

  15. Biphasic dose response in low level light therapy - an update.

    Science.gov (United States)

    Huang, Ying-Ying; Sharma, Sulbha K; Carroll, James; Hamblin, Michael R

    2011-01-01

    Low-level laser (light) therapy (LLLT) has been known since 1967 but still remains controversial due to incomplete understanding of the basic mechanisms and the selection of inappropriate dosimetric parameters that led to negative studies. The biphasic dose-response or Arndt-Schulz curve in LLLT has been shown both in vitro studies and in animal experiments. This review will provide an update to our previous (Huang et al. 2009) coverage of this topic. In vitro mediators of LLLT such as adenosine triphosphate (ATP) and mitochondrial membrane potential show biphasic patterns, while others such as mitochondrial reactive oxygen species show a triphasic dose-response with two distinct peaks. The Janus nature of reactive oxygen species (ROS) that may act as a beneficial signaling molecule at low concentrations and a harmful cytotoxic agent at high concentrations, may partly explain the observed responses in vivo. Transcranial LLLT for traumatic brain injury (TBI) in mice shows a distinct biphasic pattern with peaks in beneficial neurological effects observed when the number of treatments is varied, and when the energy density of an individual treatment is varied. Further understanding of the extent to which biphasic dose responses apply in LLLT will be necessary to optimize clinical treatments.

  16. Mitogenic properties of insulin-like growth factors I and II, insulin-like growth factor binding protein-3 and epidermal growth factor on human breast epithelial cells in primary culture.

    Science.gov (United States)

    Strange, Karen S; Wilkinson, Darcy; Emerman, Joanne T

    2002-10-01

    Insulin-like growth factor-I (IGF-I) and insulin-like growth factor-II (IGF-II) are growth factors implicated in mammary gland development and are believed to be involved in breast cancer. However, the interactions between components of the IGF system and breast epithelial cells, which give rise to breast cancer, are not well understood. We have investigated the mitogenic properties of IGF-I, IGF-II, IGF binding protein-3 (IGFBP-3) and epidermal growth factor (EGF) on human breast epithelial cells (HBEC) in primary culture. We show that, under serum-free conditions, HBEC are stimulated to grow in response to IGF-I and IGF-II in a dose-dependent manner. IGF-I and EGF, a potent stimulator of HBEC growth in primary culture and also associated with breast cancer, appear to stimulate HBEC in a synergistic manner. IGFBP-3 inhibits the stimulation by IGF-I, IGF-II and IGF-I plus EGE In addition, it appears that IGFBP-3 has an inhibitory effect on HBEC growth that is IGF-independent. This study is the first to address the effects of IGF-I, IGF-II and IGFBP-3 alone and in combination with EGF on HBEC growth in primary culture. Characterizing the role of the IGF system in normal breast biology is significant because the system has been implicated in breast cancer and a number of the anti-estrogens used in treatment are believed to function through the IGF system.

  17. Insulin biosynthesis and diabetes mellitus.

    Science.gov (United States)

    Permutt, A; Chirgwin, J; Giddings, S; Kakita, K; Rotwein, P

    1981-10-01

    This review reports the use of recombinant DNA techniques in the study of the structure and regulation of expression of insulin genes in man and experimental animals. Insulin biosynthesis by pancreatic islet cells is predominantly regulated by change in plasma glucose concentration. Using a cell-free protein synthesizing system as an assay of functional proinsulin messenger RNA (mRNA), and hybridization analysis with a cloned DNA complementary to proinsulin mRNA, it has been determined that through changes in proinsulin mRNA levels. Insulin genes of the rat, chicken and human have been isolated and sequenced. The 5' ends of the genes have similar sequences suggesting areas important for regulation of transcription. There are two non-allelic insulin genes in the rat, but only one in chickens and humans. Intervening sequences, areas of DNA transcribed into precursor mRNA but which do not appear in mature mRNA, have been described within insulin genes. The insulin gene resides on chromosome 11 of humans as determined by DNA hybridization analysis of mouse human hybrid cells. The structure of the insulin gene in genomic DNA of humans has been analyzed in diabetics and non-diabetics. Insertions of DNA between 1500 and 3400 base pairs have been detected near the transcription initiation site in 65% of type II diabetics, and 25-30% of non-diabetics (this difference is significant at the p less than 0.001 level). Limitation of these insertions to this potential promotor region of the insulin gene suggests that they may alter gene expression in type II diabetes. These insertions of DNA may prove to be useful genetic markers for diabetes.

  18. Isoorientin reverts TNF-α-induced insulin resistance in adipocytes activating the insulin signaling pathway.

    Science.gov (United States)

    Alonso-Castro, Angel Josabad; Zapata-Bustos, Rocio; Gómez-Espinoza, Guadalupe; Salazar-Olivo, Luis A

    2012-11-01

    Isoorientin (ISO) is a plant C-glycosylflavonoid with purported antidiabetic effects but unexplored mechanisms of action. To gain insight into its antidiabetic mechanisms, we assayed nontoxic ISO concentrations on the 2-(N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl) amino)-2-deoxy-d-glucose (2-NBDG) uptake by murine 3T3-F442A and human sc adipocytes. In insulin-sensitive adipocytes, ISO stimulated the 2-NBDG uptake by 210% (murine) and 67% (human), compared with insulin treatment. Notably, ISO also induced 2-NBDG uptake in murine (139%) and human (60%) adipocytes made resistant to insulin by treatment with TNF-α, compared with the incorporation induced in these cells by rosiglitazone. ISO induction of glucose uptake in adipocytes was abolished by inhibitors of the insulin signaling pathway. These inhibitors also blocked the proper phosphorylation of insulin signaling pathway components induced by ISO in both insulin-sensitive and insulin-resistant adipocytes. Additionally, ISO stimulated the transcription of genes encoding components of insulin signaling pathway in murine insulin-sensitive and insulin-resistant adipocytes. In summary, we show here that ISO exerts its antidiabetic effects by activating the insulin signaling pathway in adipocytes, reverts the insulin resistance caused in these cells by TNF-α by stimulating the proper phosphorylation of proteins in this signaling pathway, and induces the expression of genes encoding these proteins.

  19. A Lagrange multiplier mixed finite element formulation for three-dimensional contact of biphasic tissues.

    Science.gov (United States)

    Yang, Taiseung; Spilker, Robert L

    2007-06-01

    A three-dimensional (3D) contact finite element formulation has been developed for biological soft tissue-to-tissue contact analysis. The linear biphasic theory of Mow, Holmes, and Lai (1984, J. Biomech., 17(5), pp. 377-394) based on continuum mixture theory, is adopted to describe the hydrated soft tissue as a continuum of solid and fluid phases. Four contact continuity conditions derived for biphasic mixtures by Hou et al. (1989, ASME J. Biomech. Eng., 111(1), pp. 78-87) are introduced on the assumed contact surface, and a weighted residual method has been used to derive a mixed velocity-pressure finite element contact formulation. The Lagrange multiplier method is used to enforce two of the four contact continuity conditions, while the other two conditions are introduced directly into the weighted residual statement. Alternate formulations are possible, which differ in the choice of continuity conditions that are enforced with Lagrange multipliers. Primary attention is focused on a formulation that enforces the normal solid traction and relative fluid flow continuity conditions on the contact surface using Lagrange multipliers. An alternate approach, in which the multipliers enforce normal solid traction and pressure continuity conditions, is also discussed. The contact nonlinearity is treated with an iterative algorithm, where the assumed area is either extended or reduced based on the validity of the solution relative to contact conditions. The resulting first-order system of equations is solved in time using the generalized finite difference scheme. The formulation is validated by a series of increasingly complex canonical problems, including the confined and unconfined compression, the Hertz contact problem, and two biphasic indentation tests. As a clinical demonstration of the capability of the contact analysis, the gleno-humeral joint contact of human shoulders is analyzed using an idealized 3D geometry. In the joint, both glenoid and humeral head

  20. Identification of Direct and Indirect Social Network Effects in the Pathophysiology of Insulin Resistance in Obese Human Subjects

    OpenAIRE

    Henning, Christian H.C.A.; Nana Zarnekow; Johannes Hedtrich; Sascha Stark; Kathrin Türk; Matthias Laudes

    2014-01-01

    OBJECTIVE: The aim of the present study was to examine to what extent different social network mechanisms are involved in the pathogenesis of obesity and insulin-resistance. DESIGN: We used nonparametric and parametric regression models to analyse whether individual BMI and HOMA-IR are determined by social network characteristics. SUBJECTS AND METHODS: A total of 677 probands (EGO) and 3033 social network partners (ALTER) were included in the study. Data gathered from the probands include ant...

  1. Effects of cake made from whole soy powder on postprandial blood glucose and insulin levels in human subjects.

    Science.gov (United States)

    Oku, Tsuneyuki; Nakamura, Mariko; Takasugi, Ayako; Hashiguchi-Ishiguro, Michiru; Tanabe, Kenichi; Nakamura, Sadako

    2009-01-01

    We investigated the glycemic index (GI) and the insulinemic index (II) of cake made from whole soy powder (SBC) and the suppressive effects of SBC on the postprandial blood glucose and insulin by other carbohydrate foods. Furthermore, breath hydrogen excretion was simultaneously investigated. Twenty subjects were given 114 g SBC, 144 g cooked paddy-rice, and 60 g SBC with 144 g cooked paddy-rice in random order using a within-subject, repeated-measures design. Blood and end-expiratory gas were collected at the indicated periods after ingestion. The GI and the II of SBC were 22+/-6 and 48+/-29, respectively. The elevation of blood glucose by cooked paddy-rice was significantly suppressed by the addition of 60 g SBC, although the insulin secretion did not decrease. Breath hydrogen excretion by the addition of SBC to 144 g cooked paddy-rice was not significantly increased in comparison with cooked paddy-rice alone. SBC was of low GI and low II, but the postprandial insulin secretion in response to cooked paddy-rice was not suppressed.

  2. Chromium-Insulin Reduces Insulin Clearance and Enhances Insulin Signaling by Suppressing Hepatic Insulin-Degrading Enzyme and Proteasome Protein Expression in KKAy Mice.

    Science.gov (United States)

    Wang, Zhong Q; Yu, Yongmei; Zhang, Xian H; Komorowski, James

    2014-01-01

    JDS-chromium-insulin (CRI)-003 is a novel form of insulin that has been directly conjugated with chromium (Cr) instead of zinc. Our hypothesis was that CRI enhances insulin's effects by altering insulin-degrading enzyme (IDE) and proteasome enzymes. To test this hypothesis, we measured hepatic IDE content and proteasome parameters in a diabetic animal model. Male KKAy mice were randomly divided into three groups (n = 8/group); Sham (saline), human regular insulin (Reg-In), and chromium conjugated human insulin (CRI), respectively. Interventions were initiated at doses of 2 U insulin/kg body weight daily for 8-weeks. Plasma glucose and insulin were measured. Hepatic IDE, proteasome, and insulin signaling proteins were determined by western blotting. Insulin tolerance tests at week 7 showed that both insulin treatments significantly reduced glucose concentrations and increased insulin levels compared with the Sham group, CRI significantly reduced glucose at 4 and 6 h relative to Reg-In (P < 0.05), suggesting the effects of CRI on reducing glucose last longer than Reg-In. CRI treatment significantly increased hepatic IRS-1 and Akt1 and reduced IDE, 20S as well as 19S protein abundance (P < 0.01, P < 0.05, and P < 0.001, respectively), but Reg-In only significantly increased Akt1 (P < 0.05). Similar results were also observed in Reg-In- and CRI-treated HepG2 cells. This study, for the first time, demonstrates that CRI reduces plasma insulin clearance by inhibition of hepatic IDE protein expression and enhances insulin signaling as well as prevents degradation of IRS-1 and IRS-2 by suppressing ubiquitin-proteasome pathway in diabetic mice.

  3. Baculovirus-mediated gene transfer and recombinant protein expression do not interfere with insulin dependent phosphorylation of PKB/Akt in human SHSY-5Y and C3A cells

    Directory of Open Access Journals (Sweden)

    Selander Martin

    2007-02-01

    Full Text Available Abstract Background Recombinant adenovirus vectors and transfection agents comprising cationic lipids are widely used as gene delivery vehicles for functional expression in cultured cells. Consequently, these tools are utilized to investigate the effects of functional over-expression of proteins on insulin mediated events. However, we have previously reported that cationic lipid reagents cause a state of insulin unresponsiveness in cell cultures. In addition, we have found that cultured cells often do not respond to insulin stimulation following adenovirus treatment. Infection with adenovirus compromises vital functions of the host cell leading to the activation of protein kinases central to insulin signalling, such as protein kinase B/Akt. Therefore, we investigated the effect of adenovirus infection on insulin unresponsiveness by means of Akt activation in cultured cells. Moreover, we investigated the use of baculovirus as a heterologous viral gene delivery vehicle to circumvent these phenomena. Since the finding that baculovirus can efficiently transduce mammalian cells, the applications of this viral system in gene delivery has greatly expanded and one advantage is the virtual absence of cytotoxicity in mammalian cells. Results We show that infection of human neuroblastoma SHSY-5Y and liver C3A cells with recombinant adenovirus results in the activation of Akt in a dose dependent manner. In addition, this activation makes treated cells unresponsive to insulin stimulation as determined by an apparent lack of differential phosphorylation of Akt on serine-473. Our data further indicate that the use of recombinant baculovirus does not increase the phosphorylation of Akt in SHSY-5Y and C3A cells. Moreover, following infection with baculovirus, SHSY-5Y and C3A cells respond to insulin by means of phosphorylation of Akt on serine-473 in the same manner as uninfected cells. Conclusion Widely-used adenovirus vectors for gene delivery cause a state of

  4. Thermoreversible (Ionic-Liquid-Based) Aqueous Biphasic Systems.

    Science.gov (United States)

    Passos, Helena; Luís, Andreia; Coutinho, João A P; Freire, Mara G

    2016-02-04

    The ability to induce reversible phase transitions between homogeneous solutions and biphasic liquid-liquid systems, at pre-defined and suitable operating temperatures, is of crucial relevance in the design of separation processes. Ionic-liquid-based aqueous biphasic systems (IL-based ABS) have demonstrated superior performance as alternative extraction platforms, and their thermoreversible behaviour is here disclosed by the use of protic ILs. The applicability of the temperature-induced phase switching is further demonstrated with the complete extraction of two value-added proteins, achieved in a single-step. It is shown that these temperature-induced mono(bi)phasic systems are significantly more versatile than classical liquid-liquid systems which are constrained by their critical temperatures. IL-based ABS allow to work in a wide range of temperatures and compositions which can be tailored to fit the requirements of a given separation process.

  5. New resource for the computation of cartilage biphasic material properties with the interpolant response surface method.

    Science.gov (United States)

    Keenan, Kathryn E; Kourtis, Lampros C; Besier, Thor F; Lindsey, Derek P; Gold, Garry E; Delp, Scott L; Beaupre, Gary S

    2009-08-01

    Cartilage material properties are important for understanding joint function and diseases, but can be challenging to obtain. Three biphasic material properties (aggregate modulus, Poisson's ratio and permeability) can be determined using an analytical or finite element model combined with optimisation to find the material properties values that best reproduce an experimental creep curve. The purpose of this study was to develop an easy-to-use resource to determine biphasic cartilage material properties. A Cartilage Interpolant Response Surface was generated from interpolation of finite element simulations of creep indentation tests. Creep indentation tests were performed on five sites across a tibial plateau. A least-squares residual search of the Cartilage Interpolant Response Surface resulted in a best-fit curve for each experimental condition with corresponding material properties. These sites provided a representative range of aggregate moduli (0.48-1.58 MPa), Poisson's ratio (0.00-0.05) and permeability (1.7 x 10(- 15)-5.4 x 10(- 15) m(4)/N s) values found in human cartilage. The resource is freely available from https://simtk.org/home/va-squish.

  6. Higher-Resolution Structure of the Human Insulin Receptor Ectodomain: Multi-Modal Inclusion of the Insert Domain.

    Science.gov (United States)

    Croll, Tristan I; Smith, Brian J; Margetts, Mai B; Whittaker, Jonathan; Weiss, Michael A; Ward, Colin W; Lawrence, Michael C

    2016-03-01

    Insulin receptor (IR) signaling is critical to controlling nutrient uptake and metabolism. However, only a low-resolution (3.8 Å) structure currently exists for the IR ectodomain, with some segments ill-defined or unmodeled due to disorder. Here, we revise this structure using new diffraction data to 3.3 Å resolution that allow improved modeling of the N-linked glycans, the first and third fibronectin type III domains, and the insert domain. A novel haptic interactive molecular dynamics strategy was used to aid fitting to low-resolution electron density maps. The resulting model provides a foundation for investigation of structural transitions in IR upon ligand binding.

  7. Resolution of lipohypertrophy following change of short-acting insulin to insulin lispro (Humalog).

    Science.gov (United States)

    Roper, N A; Bilous, R W

    1998-12-01

    Lipohypertrophy as a local complication of insulin therapy is well recognized. Despite improvements in insulin purity and the introduction of recombinant human insulin its prevalence has remained high. Rotation of injection sites can reduce the frequency of the problem but does not abolish it. The importance of this complication is not only cosmetic but also in its impact on insulin absorption, and hence glycaemic control. We report a patient who had intractable lipohypertrophy with human recombinant insulin but experienced no such problem when converted onto the insulin analogue lispro. We suggest that the faster speed of absorption of insulin lispro may lead to less hypertrophic stimulation of subcutaneous adipocytes. This difference may be clinically useful in susceptible individuals.

  8. Integrative Genomics Outlines a Biphasic Glucose Response and a ChREBP-RORγ Axis Regulating Proliferation in β Cells

    DEFF Research Database (Denmark)

    Schmidt, Søren Fisker; Madsen, Jesper Grud Skat; Frafjord, Kari Østerli

    2016-01-01

    activity in response to glucose in the INS-1E pancreatic β cell line. Our data outline a biphasic response with a first transcriptional wave during which metabolic genes are activated, and a second wave where cell-cycle genes are activated and β cell identity genes are repressed. The glucose......Glucose is an important inducer of insulin secretion, but it also stimulates long-term adaptive changes in gene expression that can either promote or antagonize the proliferative potential and function of β cells. Here, we have generated time-resolved profiles of enhancer and transcriptional...... regulators of the second wave. These include RORγ, the activity of which is important for glucose-induced proliferation of both INS-1E and primary rat β cells....

  9. Alteration in insulin action

    DEFF Research Database (Denmark)

    Tanti, J F; Gual, P; Grémeaux, T;

    2004-01-01

    Insulin resistance, when combined with impaired insulin secretion, contributes to the development of type 2 diabetes. Insulin resistance is characterised by a decrease in insulin effect on glucose transport in muscle and adipose tIssue. Tyrosine phosphorylation of insulin receptor substrate 1 (IR...

  10. Actinide recovery using aqueous biphasic extraction: Initial developmental studies

    Energy Technology Data Exchange (ETDEWEB)

    Chaiko, D.J.; Mensah-Biney, R.; Mertz, C.J.; Rollins, A.N.

    1992-08-01

    Aqueous biphasic extraction systems are being developed to treat radioactive wastes. The separation technique involves the selective partitioning of either solutes or colloid-size particles between two scible aqueous phases. Wet grinding of plutonium residues to an average particle size of one micron will be used to liberate the plutonium from the bulk of the particle matrix. The goal is to produce a plutonium concentrate that will integrate with existing and developing chemical recovery processes. Ideally, the process would produce a nonTRU waste stream. Coupling physical beneficiation with chemical processing will result in a substantial reduction in the volume of mixed wastes generated from dissolution recovery processes. As part of this program, we will also explore applications of aqueous biphasic extraction that include the separation and recovery of dissolved species such as metal ions and water-soluble organics. The expertise and data generated in this work will form the basis for developing more cost-effective processes for handling waste streams from environmental restoration and waste management activities within the DOE community. This report summarizes the experimental results obtained during the first year of this effort. Experimental efforts were focused on elucidating the surface and solution chemistry variables which govern partitioning behavior of plutonium and silica in aqueous biphasic extraction systems. Additional efforts were directed toward the development of wet grinding methods for producing ultrafine particles with diameters of one micron or less.

  11. Comparison of In Vivo Effects of Insulin on SREBP-1c Activation and INSIG-1/2 in Rat Liver and Human and Rat Adipose Tissue

    OpenAIRE

    Boden, Guenther; Salehi, Sajad; Cheung, Peter; Homko, Carol; Song, Weiwei; Loveland-Jones, Catherine; Jayarajan, Senthil

    2013-01-01

    The stimulatory effects of insulin on de novo lipogenesis (DNL) in the liver, where it is an important contributor to non-alcoholic fatty liver disease (NAFLD), hepatic and systemic insulin resistance, is strong and well established. In contrast, insulin plays only a minor role in DNL in adipose tissue. The reason why insulin stimulates DNL more in liver than in fat is not known but may be due to differential regulation of the transcription and post-translational activation of sterol regulato...

  12. Insulin-producing cells derived from human embryonic stem cells: comparison of definitive endoderm- and nestin-positive progenitor-based differentiation strategies.

    Directory of Open Access Journals (Sweden)

    Rui Wei

    Full Text Available Human embryonic stem cells (hESCs are pluripotent and capable of undergoing multilineage differentiation into highly specialized cells including pancreatic islet cells. Thus, they represent a novel alternative source for targeted therapies and regenerative medicine for diabetes. Significant progress has been made in differentiating hESCs toward pancreatic lineages. One approach is based on the similarities of pancreatic β cell and neuroepithelial development. Nestin-positive cells are selected as pancreatic β cell precursors and further differentiated to secrete insulin. The other approach is based on our knowledge of developmental biology in which the differentiation protocol sequentially reproduces the individual steps that are known in normal β cell ontogenesis during fetal pancreatic development. In the present study, the hESC cell line PKU1.1 was induced to differentiate into insulin-producing cells (IPCs using both protocols. The differentiation process was dynamically investigated and the similarities and differences between both strategies were explored. Our results show that IPCs can be successfully induced with both differentiation strategies. The resulting IPCs from both protocols shared many similar features with pancreatic islet cells, but not mature, functional β cells. However, these differently-derived IPC cell types displayed specific morphologies and different expression levels of pancreatic islet development-related markers. These data not only broaden our outlook on hESC differentiation into IPCs, but also extend the full potential of these processes for regenerative medicine in diabetes.

  13. A PGC-1α- and muscle fibre type-related decrease in markers of mitochondrial oxidative metabolism in skeletal muscle of humans with inherited insulin resistance

    DEFF Research Database (Denmark)

    Kristensen, Jonas Møller; Skov, Vibe; Petersson, Stine Juhl;

    2014-01-01

    Insulin resistance in obesity and type 2 diabetes is related to abnormalities in mitochondrial oxidative phosphorylation (OxPhos) in skeletal muscle. We tested the hypothesis that mitochondrial oxidative metabolism is impaired in muscle of patients with inherited insulin resistance and defective...... insulin signalling....

  14. The natural PPAR agonist linoleic acid stimulated insulin release in the rat pancreas.

    Science.gov (United States)

    Lai, Min-Chuan; Teng, Tzu-Hua; Yang, Chi

    2013-11-01

    Free fatty acids play an important role in regulating animal insulin secretion response. Acute elevated free fatty acids increased animal insulin secretion and glucose-stimulated insulin secretion. In the present study, we perfused the rat pancreas to explore the effect of unsaturated fatty acids on insulin secretion. The results showed that linoleic acid, γ-linolenic acid and arachidonic acid significantly stimulated insulin secretion. Glucose (10 mM) alone induced a biphasic insulin secretion response. The peak effluent insulin concentrations increased by 444% and 800% compared with the baseline in the first and second insulin secretion phases, respectively. Based on comparison of the percentage increases, arachidonic acid, γ-linolenic acid or linoleic acid increased glucose-induced insulin release by 555% and 934%, 522% and 995% and 463% and 1,105% in the first and second insulin secretion phases, respectively. However, the percentage increases of insulin secretion decreased significantly to 402% and 564% in the first and second phases in the rats fed a high-fat diet for 13 weeks. Linoleic acid alone stimulated a 391% increase in the peak insulin concentration compared with the baseline in the rats fed a normal diet. The peak insulin concentration decreased significantly to 183% in the rats fed a long-term high-fat diet. All the results suggested that unsaturated fatty acids stimulated insulin secretion and additively increased glucose-induced insulin secretion in the perfused rat pancreas. However, the rats fed a high-fat diet had a decreased linoleic acid-induced insulin secretion response.

  15. B Lymphocyte Stimulator (BLyS is expressed in human adipocytes in vivo and is related to obesity but not to insulin resistance.

    Directory of Open Access Journals (Sweden)

    Nike Müller

    Full Text Available Inflammation and metabolism have been shown to be evolutionary linked and increasing evidence exists that pro-inflammatory factors are involved in the pathogenesis of obesity and type 2 diabetes. Until now, most data suggest that within adipose tissue these factors are secreted by cells of the innate immune system, e. g. macrophages. In the present study we demonstrate that B lymphocyte stimulator (BLyS is increased in human obesity. In contrast to several pro-inflammatory factors, we found the source of BLyS in human adipose tissue to be the adipocytes rather than immune cells. In grade 3 obese human subjects, expression of BLyS in vivo in adipose tissue is significantly increased (p<0.001. Furthermore, BLyS serum levels are elevated in grade 3 human obesity (862.5+222.0 pg/ml vs. 543.7+60.7 pg/ml in lean controls, p<0.001 and are positively correlated to the BMI (r = 0.43, p<0.0002. In the present study, bariatric surgery significantly altered serum BLyS concentrations. In contrast, weight loss due to a very-low-calorie-formula-diet (800 kcal/d had no such effect. To examine metabolic activity of BLyS, in a translational research approach, insulin sensitivity was measured in human subjects in vivo before and after treatment with the human recombinant anti-BLyS antibody belimumab. Since BLyS is known to promote B-cell proliferation and immunoglobulin secretion, the present data suggest that adipocytes of grade 3 obese human subjects are able to activate the adaptive immune system, suggesting that in metabolic inflammation in humans both, innate and adaptive immunity, are of pathophysiological relevance.

  16. A simple, economical method of converting gene expression products of insulin into recombinant insulin and its application

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhou; CHEN Hui; TANG Yuehua; FENG Youmin

    2003-01-01

    A method, by which the gene expression product of recombinant single chain insulin can be converted into insulin by directly digesting with trypsin, has been established. This method has been used in process of porcine insulin precursor (PIP), [B16Ala]PIP and [B26Ala]PIP into (desB30)insulin, (desB30)[B16Ala]insulin and (desB30)[B26Ala]insulin, respectively, and all of them retain full biological activity of that of their corresponding parent, recombinant human insulin, [B16Ala]insulin and [B26Ala]insulin. The results further demonstrate that the C-terminal residue of B chain is not necessary for insulin's biological activity. Compared with the method of transpeptidation, this method is simple, with a high yield, and avoids the use of organic reagents, and in comparison with the trypsin/carboxypeptidase method, it omits the use of carboxylpeptidase. Besides, (desB30)[B16Ala]insulin and (desB30)[B26Ala]insulin still remained without self-association property as that of their parents, which demonstrate that they are monomeric insulin. So they can be used for substituting for monomeric insulin, [B16Ala]insulin and [B26Ala]insulin, in clinical applications.

  17. Biphasic role of chondroitin sulfate in cardiac differentiation of embryonic stem cells through inhibition of Wnt/β-catenin signaling.

    Directory of Open Access Journals (Sweden)

    Robert D Prinz

    Full Text Available The glycosaminoglycan chondroitin sulfate is a critical component of proteoglycans on the cell surface and in the extracellular matrix. As such, chondroitin sulfate side chains and the sulfation balance of chondroitin play important roles in the control of signaling pathways, and have a functional importance in human disease. In contrast, very little is known about the roles of chondroitin sulfate molecules and sulfation patterns during mammalian development and cell lineage specification. Here, we report a novel biphasic role of chondroitin sulfate in the specification of the cardiac cell lineage during embryonic stem cell differentiation through modulation of Wnt/beta-catenin signaling. Lineage marker analysis demonstrates that enzymatic elimination of endogenous chondroitin sulfates leads to defects specifically in cardiac differentiation. This is accompanied by a reduction in the number of beating cardiac foci. Mechanistically, we show that endogenous chondroitin sulfate controls cardiac differentiation in a temporal biphasic manner through inhibition of the Wnt/beta-catenin pathway, a known regulatory pathway for the cardiac lineage. Treatment with a specific exogenous chondroitin sulfate, CS-E, could mimic these biphasic effects on cardiac differentiation and Wnt/beta-catenin signaling. These results establish chondroitin sulfate and its sulfation balance as important regulators of cardiac cell lineage decisions through control of the Wnt/beta-catenin pathway. Our work suggests that targeting the chondroitin biosynthesis and sulfation machinery is a novel promising avenue in regenerative strategies after heart injury.

  18. Small angle X-ray scattering-based elucidation of the self-association mechanism of human insulin analogue lys(B29)(N(e)¿-carboxyheptadecanoyl) des(B30)

    DEFF Research Database (Denmark)

    Jensen, Malene Hillerup; Wahlund, Per-Olof; Toft, Katrine Nørgaard;

    2013-01-01

    Lys(B29)(N(e)¿-carboxyheptadecanoyl) des(B30) human insulin is an insulin analogue belonging to a class of analogues designed to form soluble depots in subcutis by self-association, aiming at a protracted action. On the basis of small angle X-ray scattering (SAXS) supplemented by a range of bioph......Lys(B29)(N(e)¿-carboxyheptadecanoyl) des(B30) human insulin is an insulin analogue belonging to a class of analogues designed to form soluble depots in subcutis by self-association, aiming at a protracted action. On the basis of small angle X-ray scattering (SAXS) supplemented by a range...... provide evidence of the in solution structure of the self-associated oligomer, which is a long straight rod composed of "tense" state insulin hexamers (T(6)-hexamers) as the smallest repeating unit. The smallest oligomer building block in the process is a T(6)T(6)-dihexamer. This tense dihexamer is formed...

  19. Different short-term effect of protein and carbohydrate intake on TSH, growth hormone (GH), insulin, C-peptide, and glucagon in humans

    DEFF Research Database (Denmark)

    Matzen, L E; Andersen, B B; Jensen, B G

    1990-01-01

    hormone (GH) and thyroid stimulating hormone (TSH) to protein and carbohydrate was identical, with a reduction in both GH and TSH, and nadir occurring after 45-60 min and 120 min, respectively. During the next 120 min TSH returned to starting level after carbohydrate intake but was still reduced after...... protein intake (p less than 0.04). After both diets GH increased after the initial decline, the increase was greatest after protein intake and maximum was reached at 180 min (p less than 0.02). It has been reported that the 5'-deiodination of T4 is stimulated by insulin and inhibited by glucagon......The effect of isocaloric (500 kcal) protein and carbohydrate ingestion was studied in a crossover study in nine healthy humans. Subjects were studied twice after overnight fasting, with an interval of 3 to 7 days. Blood was collected for 240 min after food ingestion. The initial reaction of growth...

  20. Novel covalently linked insulin dimer engineered to investigate the function of insulin dimerization.

    Directory of Open Access Journals (Sweden)

    Tine N Vinther

    Full Text Available An ingenious system evolved to facilitate insulin binding to the insulin receptor as a monomer and at the same time ensure sufficient stability of insulin during storage. Insulin dimer is the cornerstone of this system. Insulin dimer is relatively weak, which ensures dissociation into monomers in the circulation, and it is stabilized by hexamer formation in the presence of zinc ions during storage in the pancreatic β-cell. Due to the transient nature of insulin dimer, direct investigation of this important form is inherently difficult. To address the relationship between insulin oligomerization and insulin stability and function, we engineered a covalently linked insulin dimer in which two monomers were linked by a disulfide bond. The structure of this covalent dimer was identical to the self-association dimer of human insulin. Importantly, this covalent dimer was capable of further oligomerization to form the structural equivalent of the classical hexamer. The covalently linked dimer neither bound to the insulin receptor, nor induced a metabolic response in vitro. However, it was extremely thermodynamically stable and did not form amyloid fibrils when subjected to mechanical stress, underlining the importance of oligomerization for insulin stability.

  1. Insulin analogues in pregnancy and specific congenital anomalies

    DEFF Research Database (Denmark)

    de Jong, Josta; Garne, Ester; Wender-Ozegowska, Ewa

    2016-01-01

    in the congenital anomaly rate among foetuses exposed to insulin analogues (lispro, aspart, glargine or detemir) compared with those exposed to human insulin or Neutral Protamine Hagedorn insulin. The total prevalence of congenital anomalies was not increased for foetuses exposed to insulin analogues. The small...... included 1286 foetuses of mothers using short-acting insulin analogues with 1089 references of mothers using human insulin and 768 foetuses of mothers using long-acting insulin analogues with 685 references of mothers using long-acting human insulin (Neutral Protamine Hagedorn). The congenital anomaly rate...... samples in the included studies provided insufficient statistical power to identify a moderate increased risk of specific congenital anomalies. Copyright © 2015 John Wiley & Sons, Ltd....

  2. Concentrated insulins: the new basal insulins

    Directory of Open Access Journals (Sweden)

    Lamos EM

    2016-03-01

    Full Text Available Elizabeth M Lamos,1 Lisa M Younk,2 Stephen N Davis3 1Division of Endocrinology, Diabetes and Nutrition, 2Department of Medicine, University of Maryland School of Medicine, 3Department of Medicine, University of Maryland Medical Center, Baltimore, MD, USA Introduction: Insulin therapy plays a critical role in the treatment of type 1 and type 2 diabetes mellitus. However, there is still a need to find basal insulins with 24-hour coverage and reduced risk of hypoglycemia. Additionally, with increasing obesity and insulin resistance, the ability to provide clinically necessary high doses of insulin at low volume is also needed. Areas covered: This review highlights the published reports of the pharmacokinetic (PK and glucodynamic properties of concentrated insulins: Humulin-R U500, insulin degludec U200, and insulin glargine U300, describes the clinical efficacy, risk of hypoglycemic, and metabolic changes observed, and finally, discusses observations about the complexity of introducing a new generation of concentrated insulins to the therapeutic market. Conclusion: Humulin-R U500 has a similar onset but longer duration of action compared with U100 regular insulin. Insulin glargine U300 has differential PK/pharmacodynamic effects when compared with insulin glargine U100. In noninferiority studies, glycemic control with degludec U200 and glargine U300 is similar to insulin glargine U100 and nocturnal hypoglycemia is reduced. Concentrated formulations appear to behave as separate molecular entities when compared with earlier U100 insulin analog compounds. In the review of available published data, newer concentrated basal insulins may offer an advantage in terms of reduced intraindividual variability as well as reducing the injection burden in individuals requiring high-dose and large volume insulin therapy. Understanding the PK and pharmacodynamic properties of this new generation of insulins is critical to safe dosing, dispensing, and administration

  3. Update on insulin treatment for dogs and cats: insulin dosing pens and more

    Directory of Open Access Journals (Sweden)

    Thompson A

    2015-04-01

    Full Text Available Ann Thompson,1 Patty Lathan,2 Linda Fleeman3 1School of Veterinary Science, The University of Queensland, Gatton, QLD, Australia; 2College of Veterinary Medicine Mississippi State University, Starkville, MS, USA; 3Animal Diabetes Australia, Melbourne, VIC, Australia Abstract: Insulin therapy is still the primary therapy for all diabetic dogs and cats. Several insulin options are available for each species, including veterinary registered products and human insulin preparations. The insulin chosen depends on the individual patient's requirements. Intermediate-acting insulin is usually the first choice for dogs, and longer-acting insulin is the first choice for cats. Once the insulin type is chosen, the best method of insulin administration should be considered. Traditionally, insulin vials and syringes have been used, but insulin pen devices have recently entered the veterinary market. Pens have different handling requirements when compared with standard insulin vials including: storage out of the refrigerator for some insulin preparations once pen cartridges are in use; priming of the pen to ensure a full dose of insulin is administered; and holding the pen device in place for several seconds during the injection. Many different types of pen devices are available, with features such as half-unit dosing, large dials for visually impaired people, and memory that can display the last time and dose of insulin administered. Insulin pens come in both reusable and disposable options. Pens have several benefits over syringes, including improved dose accuracy, especially for low insulin doses. Keywords: diabetes, mellitus, canine, feline, NPH, glargine, porcine lente

  4. [B17-D-leucine]insulin and [B17-norleucine]insulin: synthesis and biological properties.

    Science.gov (United States)

    Knorr, R; Danho, W; Büllesbach, E E; Gattner, H G; Zahn, H; King, G L; Kahn, C R

    1983-11-01

    The chemical synthesis of two porcine insulin analogues is described. Leucine in position B17 of the native molecule was substituted by its D-enantiomer and by L-norleucine, respectively. Both B-chain derivatives were synthesized by fragment condensation and purified as di-S-sulphonates by gel filtration followed by ion exchange chromatography on SP-Sephadex at pH3. Combination with native sulphhydryl A-chain yielded [DLeuB17]insulin and [NleB17]insulin. Both insulin analogues were isolated by gel filtration followed by ion exchange chromatography on CM-cellulose at pH 4.0. Biological activities of the analogues were determined relative to native pork insulin: 1) glucose oxidation in rat epididymal adipocytes was 6% for [DLeuB17]insulin and 16% for [NleB17]insulin, 2) receptor-binding affinity tested with cultured human fibroblasts and with rat adipocytes was 3% for [DLeuB17]insulin and 26% for [NleB17]insulin, and 3) thymidine incorporation into DNA of human fibroblasts was 35% for [DLeuB17]insulin and 100% for [NleB17]insulin.

  5. The acid-labile subunit of human ternary insulin-like growth factor binding protein complex in serum

    DEFF Research Database (Denmark)

    Juul, A; Møller, S; Mosfeldt-Laursen, E;

    1998-01-01

    Circulating insulin-like growth factor-I (IGF-I) is predominantly bound in the trimeric complex comprised of IGF binding protein-3 (IGFBP-3) and acid-labile subunit (ALS). Circulating concentrations of IGF-I, IGFBP-3 and ALS are believed to reflect the GH secretory status, but the clinical use...... of ALS determination is not known. We therefore, determined the: 1) hepatosplanchnic release of ALS by liver vein catheterization (n=30); 2) 24-h diurnal variation of ALS (n=8); 3) normal age-related ranges of circulating ALS (n=1158); 4) diagnostic value of ALS in 108 patients with childhood-onset GH...... deficiency (GHD). We found: 1) no significant arteriovenous gradient over the liver ofALS, IGF-I, and IGFBP-3; 2) the diurnal variation of ALS was 12% (mean coefficient of variation percent); 3) ALS levels increased throughout childhood with maximal levels in puberty, with a subsequent decrease with age...

  6. Lipid mobilization in subcutaneous adipose tissue during exercise in lean and obese humans. Roles of insulin and natriuretic peptides

    DEFF Research Database (Denmark)

    Koppo, Katrien; Larrouy, Dominique; Marques, Marie A;

    2010-01-01

    to 2 microU/ml), blunted the exercise-induced rise in plasma GH and epinephrine levels in both groups, and enhanced the exercise-induced natriuretic peptide (NP) levels in lean but not in obese subjects. In both groups, octreotide infusion resulted in higher exercise-induced increases in dialysate...... glycerol concentrations in the phentolamine-containing probe while no difference in lipolytic response was found in the aminophylline-containing probe. The results suggest that insulin antilipolytic action plays a role in the regulation of lipolysis during exercise in lean as well as in obese subjects....... The octreotide-induced enhancement of exercise lipolysis in lean subjects was associated with an increased exercise-induced plasma NP response. Adenosine may contribute to the inhibition of basal lipolysis in both subject groups....

  7. The effect of different alcoholic beverages on blood alcohol levels, plasma insulin and plasma glucose in humans.

    Science.gov (United States)

    Nogueira, L C; Couri, S; Trugo, N F; Lollo, P C B

    2014-09-01

    In the present work we studied the effects of four alcoholic beverages on blood alcohol levels, plasma insulin concentrations and plasma glucose concentrations in men and women. The volunteers were healthy non-smokers and they were divided according to sex into two groups of ten individuals. The alcoholic beverages used in the study were beer, red wine, whisky and "cachaça". In men, ingestion of the distilled drinks promoted a spike in blood alcohol levels more quickly than ingestion of the fermented drinks. In women, beer promoted the lowest blood alcohol levels over the 6h of the experiment. Whisky promoted highest blood alcohol levels in both sexes. The ingestion of wine promoted a significant difference in relation to the blood alcohol concentration (BAC) as a function of gender. The ingestion of cachaça by women produced BAC levels significantly smaller than those obtained for wine.

  8. Lipid mobilization in subcutaneous adipose tissue during exercise in lean and obese humans. Roles of insulin and natriuretic peptides.

    Science.gov (United States)

    Koppo, Katrien; Larrouy, Dominique; Marques, Marie A; Berlan, Michel; Bajzova, Magda; Polak, Jan; Van de Voorde, Johan; Bülow, Jens; Lafontan, Max; Crampes, François; Langin, Dominique; Stich, Vladimir; de Glisezinski, Isabelle

    2010-08-01

    The aim of this study was to evaluate the relative contributions of various hormones involved in the regulation of lipid mobilization in subcutaneous adipose tissue (SCAT) during exercise and to assess the impact of obesity on this regulation. Eight lean and eight obese men performed a 60-min cycle exercise bout at 50% of their peak oxygen uptake on two occasions: during intravenous infusion of octreotide (a somatostatin analog) or physiological saline (control condition). Lipolysis in SCAT was evaluated using in situ microdialysis. One microdialysis probe was perfused with the adrenergic blockers phentolamine and propranolol while another probe was perfused with the phosphodiesterase and adenosine receptor inhibitor aminophylline. Compared with the control condition, infusion of octreotide reduced plasma insulin levels in lean (from approximately 3.5 to 0.5 microU/ml) and in obese (from approximately 9 to 2 microU/ml), blunted the exercise-induced rise in plasma GH and epinephrine levels in both groups, and enhanced the exercise-induced natriuretic peptide (NP) levels in lean but not in obese subjects. In both groups, octreotide infusion resulted in higher exercise-induced increases in dialysate glycerol concentrations in the phentolamine-containing probe while no difference in lipolytic response was found in the aminophylline-containing probe. The results suggest that insulin antilipolytic action plays a role in the regulation of lipolysis during exercise in lean as well as in obese subjects. The octreotide-induced enhancement of exercise lipolysis in lean subjects was associated with an increased exercise-induced plasma NP response. Adenosine may contribute to the inhibition of basal lipolysis in both subject groups.

  9. Angiotensin and insulin resistance: conspiracy theory.

    Science.gov (United States)

    Townsend, Raymond R

    2003-04-01

    Resistance to the metabolic effects of insulin is a contender for the short list of major cardiovascular risk factors. Since the elements of the syndrome of insulin resistance were first articulated together in 1988, numerous epidemiologic investigations and treatment endeavors have established a relationship between the metabolic disarray of impaired insulin action and cardiovascular disease. Angiotensin II, the primary effector of the renin-angiotensin system, has also achieved a place in the chronicles of cardiovascular risk factors. Conspiracy mechanisms by which angiotensin II and insulin resistance interact in the pathogenesis of cardiovascular disease are reviewed, with particular attention to recent developments in this engaging area of human research.

  10. Ghrelin- and GH-induced insulin resistance

    DEFF Research Database (Denmark)

    Vestergaard, Esben Thyssen; Krag, Morten B; Poulsen, Morten M

    2013-01-01

    Supraphysiological levels of ghrelin and GH induce insulin resistance. Serum levels of retinol-binding protein-4 (RBP4) correlate inversely with insulin sensitivity in patients with type 2 diabetes. We aimed to determine whether ghrelin and GH affect RBP4 levels in human subjects....

  11. Effect on peripheral nerve regeneration by transgene in vivo with human insulin-like growth factor-1

    Institute of Scientific and Technical Information of China (English)

    Jiaxiang Gu; Yufa Wang; Shanhe Dai

    2006-01-01

    BACKGROUND: Human insulin-like growth factor (hIGF-1) has been successful in treating peripheral nerve injury, but it is still unclear whether hlGF-1 after transgene in vivo has the effect on promoting the regeneration of peripheral nerve. OBJECTIVE: To observe the effect of hlGF-1 on the regeneration of peripheral nerve by transgene in vivo with electrophysiology, histological morphology and ultromicro morphology. DESIGN: A univariate design. SETTINGS: Jilin Institute of Surgery, China-Japan Friendship Hospital Affiliated to Jilin University; School of Basic Medical Sciences, Jilin University. MATERIALS: Thirty male adult Wistar rats of grade Ⅱ, weighing 200-250 g, were provided by the Animal Experimental Center of Jilin University [certification number: SCXK-(Ji)20030001]. The rats were raised in the environment at the temperature of 25 ℃ and humidity of 70%. All the rats were randomly divided into hlGF-1-treated group, treatment control group and blank control group, 10 rats in each group. Positive liposomes (mass concentration of 2 g/L) and pcDNA3.1 (mass concentration of 1 g/L) were purchased from Beijing Yuanpinghao Company; pcDNAhlGF-1 (mass concentration of 1 g/L) was provided by Dr. Shen from the School of Public Health of Jilin University. The liposomes were mixed with plasmids with the mass ratio of 1.5 to 10.Operative microscope was made by Jiangsu Zhenjiang Microsurgical Instrument Factory; EMB-5304K electromyogram (EMG) evoked potential meter by Nihon Kohden Corporation. HPIAS-1 000 high-acuity color pathological imaging analytical system (Japan) and JEM-1200EX transmission electron microscope (Japan) were also used. METHODS: The experiments were carried out in Jilin Institute of Surgery from April to June in 2004. ① All the rats were anesthetized, and the right sciatic nerve was exposed, and it was clipped with a clip at 5 mm below the piriform muscle for 3 times, 10 s for each time. The pressed width was 3 mm, and formed as membrane under

  12. Insulin analogues: have they changed insulin treatment and improved glycaemic control?

    DEFF Research Database (Denmark)

    Madsbad, Sten

    2002-01-01

    To improve insulin therapy, new insulin analogues have been developed. Two fast-acting analogues with a more rapid onset of effect and a shorter duration of action combined with a low day-to-day variation in absorption rate are now available. Despite this favourable time-action profile most studies....... This is probably the main explanation for the absence of improvement in overall glycaemic control when compared with regular human insulin. A tendency to a reduction in hypoglycaemic events during treatment with fast-acting analogues has been observed in most studies. Recent studies have indicated that NPH insulin...... administered several times daily at mealtimes can improve glycaemic control without increasing the risk of hypoglycaemia. The fast-acting analogues are now also available as insulin mixed with NPH. Insulin glargine is a new long-acting insulin which is soluble and precipitates after injection, resulting...

  13. [Beyond immunopathogenesis. Insulin resistance and "epidermal dysfunction"].

    Science.gov (United States)

    Boehncke, W-H; Boehncke, S; Buerger, C

    2012-03-01

    Insulin is a central player in the regulation of metabolic as well as non-metabolic cells: inefficient signal transduction (insulin resistance) not only represents the cornerstone in the pathogenesis of type 2 diabetes mellitus, but also drives atherosclerosis through inducing endothelial dysfunction. Last but not least epidermal homeostasis depends on insulin. We summarize the effects of insulin on proliferation and differentiation of human keratinocytes as well as the relevance of cytokine-induced insulin resistance for alterations in epidermal homeostasis characteristic for psoriasis. Kinases involved in both insulin- as well as cytokine-receptor signaling represent potential targets for innovative therapeutics. Such small molecules would primarily normalize "epidermal dysfunction", thus complementing the immunomodulatory strategies of today's biologics.

  14. Animal models of insulin resistance: A review.

    Science.gov (United States)

    Sah, Sangeeta Pilkhwal; Singh, Barinder; Choudhary, Supriti; Kumar, Anil

    2016-12-01

    Insulin resistance can be seen as a molecular and genetic mystery, with a role in the pathophysiology of type 2 diabetes mellitus. It is a basis for a number of chronic diseases like hypertension, dyslipidemia, glucose intolerance, coronary heart disease, cerebral vascular disease along with T2DM, thus the key is to cure and prevent insulin resistance. Critical perspicacity into the etiology of insulin resistance have been gained by the use of animal models where insulin action has been modulated by various transgenic and non-transgenic models which is not possible in human studies. The following review comprises the pathophysiology involved in insulin resistance, various factors causing insulin resistance, their screening and various genetic and non-genetic animal models highlighting the pathological and metabolic characteristics of each.

  15. Accelerated Maturation of Human Stem Cell-Derived Pancreatic Progenitor Cells into Insulin-Secreting Cells in Immunodeficient Rats Relative to Mice

    Directory of Open Access Journals (Sweden)

    Jennifer E. Bruin

    2015-12-01

    Full Text Available Pluripotent human embryonic stem cells (hESCs are a potential source of transplantable cells for treating patients with diabetes. To investigate the impact of the host recipient on hESC-derived pancreatic progenitor cell maturation, cells were transplanted into immunodeficient SCID-beige mice or nude rats. Following the transplant, basal human C-peptide levels were consistently higher in mice compared with rats, but only rats showed robust meal- and glucose-responsive human C-peptide secretion by 19–21 weeks. Grafts from rats contained a higher proportion of insulin:glucagon immunoreactivity, fewer exocrine cells, and improved expression of mature β cell markers compared with mice. Moreover, ECM-related genes were enriched, the collagen network was denser, and blood vessels were more intricately integrated into the engrafted endocrine tissue in rats relative to mice. Overall, hESC-derived pancreatic progenitor cells matured faster in nude rats compared with SCID-beige mice, indicating that the host recipient can greatly influence the fate of immature pancreatic progenitor cells post-transplantation.

  16. Effect of nanostructure on osteoinduction of porous biphasic calcium phosphate ceramics.

    Science.gov (United States)

    Li, Bo; Liao, Xiaoling; Zheng, Li; Zhu, Xiangdong; Wang, Zhe; Fan, Hongsong; Zhang, Xingdong

    2012-10-01

    In order to evaluate the effect of the nanostructure of calcium phosphate ceramics on osteoinductive potential, porous biphasic calcium phosphate (BCP) ceramics with a nano- or submicron structure were prepared via microwave sintering and compared to conventional BCP ceramics. The selective protein adsorption of bovine serum albumin and lysozyme (LSZ) and the osteogenic differentiation of human mesenchymal stem cells in vitro was investigated. Porous BCP nanoceramics showed higher ability to adsorb proteins, especially low molecular weight protein of LSZ, than conventional BCP ceramics, and the BCP nanoceramics promoted bone sialoprotein expression more than conventional BCP did. Further in vivo study to investigate ectopic bone formation and bone repair efficiency proved the highly osteoinductive potential of nanostructured BCP ceramics. The results suggest that nanostructured BCP ceramics have the potential to become a new generation of bioceramics for bone tissue engineering grafts.

  17. Inhibition of human MCF-7 breast cancer cells and HT-29 colon cancer cells by rice-produced recombinant human insulin-like growth binding protein-3 (rhIGFBP-3.

    Directory of Open Access Journals (Sweden)

    Stanley C K Cheung

    Full Text Available BACKGROUND: Insulin-like growth factor binding protein-3 (IGFBP-3 is a multifunctional molecule which is closely related to cell growth, apoptosis, angiogenesis, metabolism and senescence. It combines with insulin-like growth factor-I (IGF-I to form a complex (IGF-I/IGFBP-3 that can treat growth hormone insensitivity syndrome (GHIS and reduce insulin requirement in patients with diabetes. IGFBP-3 alone has been shown to have anti-proliferation effect on numerous cancer cells. METHODOLOGY/PRINCIPAL FINDINGS: We reported here an expression method to produce functional recombinant human IGFBP-3 (rhIGFBP-3 in transgenic rice grains. Protein sorting sequences, signal peptide and endoplasmic reticulum retention tetrapeptide (KDEL were included in constructs for enhancing rhIGFBP-3 expression. Western blot analysis showed that only the constructs with signal peptide were successfully expressed in transgenic rice grains. Both rhIGFBP-3 proteins, with or without KDEL sorting sequence inhibited the growth of MCF-7 human breast cancer cells (65.76 ± 1.72% vs 45.00 ± 0.86%, p < 0.05; 50.84 ± 1.97% vs 45.00 ± 0.86%, p < 0.01 respectively and HT-29 colon cancer cells (65.14 ± 3.84% vs 18.01 ± 13.81%, p < 0.05 and 54.7 ± 9.44% vs 18.01 ± 13.81%, p < 0.05 respectively when compared with wild type rice. CONCLUSION/SIGNIFICANCE: These findings demonstrated the feasibility of producing biological active rhIGFBP-3 in rice using a transgenic approach, which will definitely encourage more research on the therapeutic use of hIGFBP-3 in future.

  18. A new kinetic biphasic approach applied to biodiesel process intensification

    Energy Technology Data Exchange (ETDEWEB)

    Russo, V.; Tesser, R.; Di Serio, M.; Santacesaria, E. [Naples Univ. (Italy). Dept. of Chemistry

    2012-07-01

    Many different papers have been published on the kinetics of the transesterification of vegetable oil with methanol, in the presence of alkaline catalysts to produce biodiesel. All the proposed approaches are based on the assumption of a pseudo-monophasic system. The consequence of these approaches is that some experimental aspects cannot be described. For the reaction performed in batch conditions, for example, the monophasic approach is not able to reproduce the different plateau obtained by using different amount of catalyst or the induction time observed at low stirring rates. Moreover, it has been observed by operating in continuous reactors that micromixing has a dramatic effect on the reaction rate. At this purpose, we have recently observed that is possible to obtain a complete conversion to biodiesel in less than 10 seconds of reaction time. This observation is confirmed also by other authors using different types of reactors like: static mixers, micro-reactors, oscillatory flow reactors, cavitational reactors, microwave reactors or centrifugal contactors. In this work we will show that a recently proposed biphasic kinetic approach is able to describe all the aspects before mentioned that cannot be described by the monophasic kinetic model. In particular, we will show that the biphasic kinetic model can describe both the induction time observed in the batch reactors, at low stirring rate, and the very high conversions obtainable in a micro-channel reactor. The adopted biphasic kinetic model is based on a reliable reaction mechanism that will be validated by the experimental evidences reported in this work. (orig.)

  19. The Streptococcus pneumoniae pilus-1 displays a biphasic expression pattern.

    Directory of Open Access Journals (Sweden)

    Gabriella De Angelis

    Full Text Available The Streptococcus pneumoniae pilus-1 is encoded by pilus islet 1 (PI-1, which has three clonal variants (clade I, II and III and is present in about 30% of clinical pneumococcal isolates. In vitro and in vivo assays have demonstrated that pilus-1 is involved in attachment to epithelial cells and virulence, as well as protection in mouse models of infection. Several reports suggest that pilus-1 expression is tightly regulated and involves the interplay of numerous genetic regulators, including the PI-1 positive regulator RlrA. In this report we provide evidence that pilus expression, when analyzed at the single-cell level in PI-1 positive strains, is biphasic. In fact, the strains present two phenotypically different sub-populations of bacteria, one that expresses the pilus, while the other does not. The proportions of these two phenotypes are variable among the strains tested and are not influenced by genotype, serotype, growth conditions, colony morphology or by the presence of antibodies directed toward the pilus components. Two sub-populations, enriched in pilus expressing or not expressing bacteria were obtained by means of colony selection and immuno-detection methods for five strains. PI-1 sequencing in the two sub-populations revealed the absence of mutations, thus indicating that the biphasic expression observed is not due to a genetic modification within PI-1. Microarray expression profile and western blot analyses on whole bacterial lysates performed comparing the two enriched sub-populations, revealed that pilus expression is regulated at the transcriptional level (on/off regulation, and that there are no other genes, in addition to those encoded by PI-1, concurrently regulated across the strains tested. Finally, we provide evidence that the over-expression of the RrlA positive regulator is sufficient to induce pilus expression in pilus-1 negative bacteria. Overall, the data presented here suggest that the observed biphasic pilus

  20. Effects of metformin on body weight in patients with type 2 diabetes mellitus,receiving insulin analogue treatment

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    T I Romantsova

    2013-03-01

    Full Text Available Aims. To study the dynamics of body weight, waist circumference, blood lipid and insulin demand in patients with type 2 diabetes mellitus (T2DM during first year of combined treatment with metformin and insulin analogues, compared with insulin analogue monotherapy.Materials and Methods. We examined 78 patients with T2DM on newly initiated insulin therapy, including 54 females and 24 males. Median age was 56 [51.0; 64.0] years, median disease duration – 9 [6.8;14.0] years. Participants were subdivided in two groups. First group was comprised of 48 subjects (33 females and 15 males, who received monotherapy with insulin analogues (glargine, de- temir, biphasic Aspart 30 and Humalog Mix 25 or rapid-acting lispro and aspart. Second group included 30 patients (18 females and12 males, who were treated with combined therapy (insulin analogues plus metformin. We measured HbA1c, plasma lipid composition, BMI, waist circumference and insulin demand initially and after one year of follow-up.Results. We showed that combined therapy vs. insulin monotherapy allows better glycemic compensation while reducing insulin demand and lowering risks for weight gain.Conclusions. Combined insulin analogue plus metformin treatment delivers better metabolic control in patients with T2DM and is as- sociated with lower risks for body weight gain and increase in insulin demand against monotherapy with insulin analogues.

  1. Chromium-insulin reduces insulin clearance and enhances insulin signaling by suppressing hepatic insulin-degrading enzyme and proteasome protein expression in KKAy mice

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    Zhong Q Wang

    2014-07-01

    Full Text Available JDS-CRI-003 (CRI is a novel form of insulin that has been directly conjugated with chromium (Cr instead of zinc. Our hypothesis was that CRI enhances insulin’s effects by altering insulin degrading enzyme (IDE and proteasome enzymes. To test this hypothesis, we measured hepatic IDE content and proteasome parameters in a diabetic animal model. Male KKAy mice were randomly divided into three groups (n=8/group; Sham (saline, human insulin (Reg-In and chromium conjugated human insulin (CRI, respectively. Interventions were initiated at doses of 2 U insulin/kg body weight daily for eight-weeks. Plasma glucose and insulin were measured. Hepatic IDE, proteasome and insulin signaling proteins were determined by western blotting. Insulin tolerance tests at week 7 showed that both insulin treatments significantly reduced glucose concentrations and increased insulin levels compared with the Sham group, CRI significantly reduced glucose at 4 and 6 hours relative to Reg-In (P<0.05, suggesting the effects of CRI on reducing glucose last longer than Reg-In. CRI treatment significantly increased hepatic IRS-1 and Akt1 and reduced IDE, 20S as well as 19S protein abundance (P<0.01, P<0.05, and P<0.001, respectively, but Reg-In only significantly increased Akt1 (P<0.05. Similar results were also observed in Reg-In and CRI treated HepG2 cells. This study, for the first time, demonstrates that CRI reduces plasma insulin clearance by inhibition of hepatic IDE protein expression and enhances insulin signaling as well as prevents degradation of IRS-1 and IRS-2 by suppressing ubiquitin-proteasome pathway in diabetic mice.

  2. Epidermal growth factor suppresses insulin-like growth factor binding protein 3 levels in human papillomavirus type 16-immortalized cervical epithelial cells and thereby potentiates the effects of insulin-like growth factor 1.

    Science.gov (United States)

    Hembree, J R; Agarwal, C; Eckert, R L

    1994-06-15

    Human ectocervical epithelial cells are a primary target for infection by oncogenic papillomaviruses, which are strongly implicated as causative agents in the genesis of cervical cancer. Growth factors have been implicated as agents that stimulate proliferation and enhance the possibility of malignant transformation. In the present study we utilize several human papillomavirus (HPV) type 16-immortalized ectocervical epithelial cell lines to investigate the effects of epidermal growth factor (EGF) and insulin-like growth factor I (IGF-I) on cell proliferation and the production of IGF binding proteins (IGFBPs). ECE16-1 cells, an HPV16-immortalized/nontumorigenic cell line, maintained in defined medium, produce and release high levels of IGFBP-3 (38/42 kDa) as well as smaller amounts of a 24-kDa IGFBP. Supplementation of defined medium with EGF causes a dose-dependent increase in cell growth and a concomitant decrease in the levels of IGFBP-3 released into the culture medium. EGF suppression of IGFBP-3 is maintained even when EGF-stimulated cell growth is suppressed 67% due to the simultaneous presence of 3 ng/ml of TGF beta 1, indicating that EGF suppression of IGFBP-3 levels is independent of EGF effects on cell growth. EGF suppression of IGFBP-3 production is correlated with a reduction in IGFBP-3 mRNA level. In the presence of EGF, the growth response of the cells to ng amounts of IGF-I is significantly enhanced. Moreover, the simultaneous presence of both EGF and IGF-I reduces the level of IGFBP-3 more efficiently than EGF alone. We also observe that the IGFBP-3 level is decreased and the 24-kDa IGFBP level is increased in HPV16-positive tumorigenic versus nontumorigenic cell lines. This is the first report of EGF acting as a positive regulator of IGF-I action via the IGFBPs. On the basis of these findings, we propose that EGF stimulates ECE16-1 cell growth via a dual-action mechanism by (a) stimulating growth directly via the EGF mitogenic pathway and (b

  3. Effects of insulin detemir and NPH insulin on renal handling of sodium, fluid retention and weight in type 2 diabetic patients

    DEFF Research Database (Denmark)

    Hendriksen, K V; Jensen, Tonny Joran; Oturai, P;

    2012-01-01

    In type 2 diabetic patients, insulin detemir (B29Lys(ε-tetradecanoyl),desB30 human insulin) induces less weight gain than NPH insulin. Due to the proposed reduction of tubular action by insulin detemir, type 2 diabetic patients should have increased urinary sodium excretion, thereby reducing extr...

  4. Insulin analogues and severe hypoglycaemia in type 1 diabetes

    DEFF Research Database (Denmark)

    Kristensen, P L; Hansen, L S; Jespersen, M J

    2012-01-01

    The effect of insulin analogues on glycaemic control is well-documented, whereas the effect on avoidance of severe hypoglycaemia remains tentative. We studied the frequency of severe hypoglycaemia in unselected patients with type 1 diabetes treated with insulin analogues, human insulin, or mixed...

  5. Glucose lowering effect of transgenic human insulin-like growth factor-I from rice: in vitro and in vivo studies

    Directory of Open Access Journals (Sweden)

    Sun Samuel SM

    2011-04-01

    Full Text Available Abstract Background Human insulin-like growth factor-I (hIGF-I is a growth factor which is highly resemble to insulin. It is essential for cell proliferation and has been proposed for treatment of various endocrine-associated diseases including growth hormone insensitivity syndrome and diabetes mellitus. In the present study, an efficient plant expression system was developed to produce biologically active recombinant hIGF-I (rhIGF-I in transgenic rice grains. Results The plant-codon-optimized hIGF-I was introduced into rice via Agrobacterium-mediated transformation. To enhance the stability and yield of rhIGF-I, the endoplasmic reticulum-retention signal and glutelin signal peptide were used to deliver rhIGF-I to endoplasmic reticulum for stable accumulation. We found that only glutelin signal peptide could lead to successful expression of hIGF-I and one gram of hIGF-I rice grain possessed the maximum activity level equivalent to 3.2 micro molar of commercial rhIGF-I. In vitro functional analysis showed that the rice-derived rhIGF-I was effective in inducing membrane ruffling and glucose uptake on rat skeletal muscle cells. Oral meal test with rice-containing rhIGF-I acutely reduced blood glucose levels in streptozotocin-induced and Zucker diabetic rats, whereas it had no effect in normal rats. Conclusion Our findings provided an alternative expression system to produce large quantities of biologically active rhIGF-I. The provision of large quantity of recombinant proteins will promote further research on the therapeutic potential of rhIGF-I.

  6. Identification and localization of insulin-like growth factor-binding protein (IGFBP) messenger RNAs in human hair follicle dermal papilla.

    Science.gov (United States)

    Batch, J A; Mercuri, F A; Werther, G A

    1996-03-01

    The role of the insulin-like growth factors (IGFs) in hair follicle biology has recently been recognized, although their actions, sites of production, and modulation by the insulin-like growth factor-binding proteins (IGFBPs) have not to date been defined. IGF-I is essential for normal hair growth and development, and may be important in regulation of the hair growth cycle. In many culture systems, IGF-I actions are modulated by the IGFBPs. Thus, if IGFBPs are produced in the human hair follicle, they may play a role in targeting IGF-I to its receptor or may modulate IGF-I action by interaction with matrix proteins. We have used in situ hybridization to localize messenger RNA for the six IGFBPs in anagen hair follicles. Anti-sense and sense RNA probes for the IGFBPs (IGFBP-1 to -6) were produced, and 5-micrometer sections of adult facial skin were probed. Messenger RNA for IGFBP-3, -4, and -5 were identified, with predominantly IGFBP-3 and -5 mRNA found in the dermal papilla, and to a lesser extent IGFBP-4 mRNA. IGFBP-4 mRNA was also found at the dermal papilla/epithelial matrix border. Messenger RNAs for both IGFBP-4 and -5 were also demonstrated in the dermal sheath surrounding the hair follicle. Messenger RNAs for IGFBP-1, -2, and -6 were not identified. These studies demonstrate specific localization of IGFBP mRNAs in hair follicles, suggesting that they each play specific roles in the local modulation of IGF action during the hair growth cycle.

  7. Relationship between Insuline-like Growth Factor-Ⅰ and Progesterone Secretion of Cultured Human Trophoblast Cells in Vitro

    Institute of Scientific and Technical Information of China (English)

    Xiao-jin ZHANG; Sui-qi GUI; Lin CAO; Zu-yue SUN

    2007-01-01

    Objective To investigate the effect of insuline-like growth factor-Ⅰ(IGF-Ⅰ) on progesterone genesis and regulation.Methods Cytotrophoblast cells were collected by trypsin-collagenase digestion and percoll gradient centrifugation for primary culture.After stimulated with different concentrations(1 00 μg/ml,10 μg/ml,1μg/ml,0.1 μg/ml) of IGF-Ⅰat the same time and with different duration(12 h, 24 h, 48 h,72 h) of IGF-Ⅰ with the same concentration, progesterone levels in the media were measured by radioimmunoassay.Simultaneously,semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) was applied to determine the expression of low density lipoprotein receptor (LDLR) mRNA.Results Progesterone levels correlated positively with IGF-Ⅰalong with the IGF-Ⅰconcentration increasing,progesterone level began to increase at 12 h,and reached the climax at 48 h when cultured with 100 μg/L IGF-Ⅰ. The expression of LDLR mRNA was detectable in every group and accordant with variation of progesterone level.Conclusion Progesterone secretion has time- and dose-dependent effect on IGF-Ⅰ,and IGF-Ⅰcan up-regulate the expression of LDLR mRNA. IGF-Ⅰmay play an important role in promoting secretion of progesterone in trophoblast cells.

  8. Do nutrient-gut-microbiota interactions play a role in human obesity, insulin resistance and type 2 diabetes?

    Science.gov (United States)

    Diamant, M; Blaak, E E; de Vos, W M

    2011-04-01

    The current obesity and type 2 diabetes pandemics have causes beyond changes in eating and exercise habits against a susceptible genetic background. Gut bacteria seem to additionally contribute to the differences in body weight, fat distribution, insulin sensitivity and glucose- and lipid-metabolism. Data, mostly derived from preclinical studies, suggest that gut microbiota play an important role in conditions such as obesity, diabetes, metabolic syndrome and non-alcoholic fatty liver disease. Regulation of energy uptake from the gut, by digesting otherwise indigestible common polysaccharides in our diet, production or activation of signalling molecules involved in host metabolism, modification of gut permeability, the release of gut hormones and inflammation, are among the mechanisms by which gut microbiota may influence the host cardiometabolic phenotype. Recent evidence suggests that quantitative and qualitative differences in gut microbiota exist between lean and obese, and between diabetic and non-diabetic individuals. Modification of the gut microbiota composition and/or its biochemical capacity by specific dietary or pharmacological interventions may favourably affect host metabolism. Large-scale intervention trials, investigating the potential benefit of prebiotics and probiotics in improving cardiometabolic health in high-risk populations, are eagerly awaited.

  9. Insulin sensitivity and hemodynamic responses to insulin in Wistar-Kyoto and spontaneously hypertensive rats.

    Science.gov (United States)

    Pître, M; Nadeau, A; Bachelard, H

    1996-10-01

    The insulin-mediated vasodilator effect has been proposed as an important physiological determinant of insulin action on glucose disposal in normotensive humans. The present study was designed to further examine the acute regional hemodynamic effects of insulin in different vascular beds and to explore the relationships between insulin vascular effects and insulin sensitivity during euglycemic hyperinsulinemic clamps in conscious normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). The rats were instrumented with intravascular catheters and pulsed Doppler flow probes to measure blood pressure, heart rate, and regional blood flows. In WKY rats, the euglycemic infusion of insulin (4 and 16 mU.kg-1.min-1) causes vasodilations in renal and hindquarter vascular beds but no changes in mean blood pressure, heart rate, or superior mesenteric vascular conductance. In contrast, in SHR, the same doses of insulin produce vasoconstrictions in superior mesenteric and hindquarter vascular beds and, at high doses, increase blood pressure. Moreover, at the lower dose of insulin tested, we found a reduction in the insulin sensitivity index in the SHR compared with the WKY rats. The present findings provide further evidence for an association between insulin sensitivity and insulin-mediated hemodynamic responses.

  10. Pathophysiological mechanisms of insulin resistance

    NARCIS (Netherlands)

    Brands, M.

    2013-01-01

    In this thesis we studied pathophysiological mechanisms of insulin resistance in different conditions in humans, i.e. in obesity, during lipid infusions, after hypercaloric feeding, and glucocorticoid treatment. We focused on 3 important hypotheses that are suggested to be implicated in the pathophy

  11. miR-503 inhibits platelet-derived growth factor-induced human aortic vascular smooth muscle cell proliferation and migration through targeting the insulin receptor.

    Science.gov (United States)

    Bi, Rui; Ding, Fangbao; He, Yi; Jiang, Lianyong; Jiang, Zhaolei; Mei, Ju; Liu, Hao

    2016-12-01

    Abnormal proliferation and migration of vascular smooth muscle cells (VSMC) is a common feature of disease progression in atherosclerosis. Here, we investigated the potential role of miR-503 in platelet-derived growth factor (PDGF)-induced proliferation and migration of human aortic smooth muscle cells and the underlying mechanisms of action. miR-503 expression was significantly downregulated in a dose- and time-dependent manner following PDGF treatment. Introduction of miR-503 mimics into cultured SMCs significantly attenuated cell proliferation and migration induced by PDGF. Bioinformatics analyses revealed that the insulin receptor (INSR) is a target candidate of miR-503. miR-503 suppressed luciferase activity driven by a vector containing the 3'-untranslated region of INSR in a sequence-specific manner. Downregulation of INSR appeared critical for miR-503-mediated inhibitory effects on PDGF-induced cell proliferation and migration in human aortic SMCs. Based on the collective data, we suggest a novel role of miR-503 as a regulator of VSMC proliferation and migration through modulating INSR.

  12. Gestational Diabetes Alters Offspring DNA Methylation Profiles in Human and Rat: Identification of Key Pathways Involved in Endocrine System Disorders, Insulin Signaling, Diabetes Signaling, and ILK Signaling.

    Science.gov (United States)

    Petropoulos, Sophie; Guillemin, Claire; Ergaz, Zivanit; Dimov, Sergiy; Suderman, Matthew; Weinstein-Fudim, Liza; Ornoy, Asher; Szyf, Moshe

    2015-06-01

    Gestational diabetes is associated with risk for metabolic disease later in life. Using a cross-species approach in rat and humans, we examined the hypothesis that gestational diabetes during pregnancy triggers changes in the methylome of the offspring that might be mediating these risks. We show in a gestation diabetes rat model, the Cohen diabetic rat, that gestational diabetes triggers wide alterations in DNA methylation in the placenta in both candidate diabetes genes and genome-wide promoters, thus providing evidence for a causal relationship between diabetes during pregnancy and DNA methylation alterations. There is a significant overlap between differentially methylated genes in the placenta and the liver of the rat offspring. Several genes differentially methylated in rat placenta exposed to maternal diabetes are also differentially methylated in the human placenta of offspring exposed to gestational diabetes in utero. DNA methylation changes inversely correlate with changes in expression. The changes in DNA methylation affect known functional gene pathways involved in endocrine function, metabolism, and insulin responses. These data provide support to the hypothesis that early-life exposures and their effects on metabolic disease are mediated by DNA methylation changes. This has important diagnostic and therapeutic implications.

  13. IMC-A12, a human IgG1 monoclonal antibody to the insulin-like growth factor I receptor.

    Science.gov (United States)

    Rowinsky, Eric K; Youssoufian, Hagop; Tonra, James R; Solomon, Phillip; Burtrum, Douglas; Ludwig, Dale L

    2007-09-15

    Targeted monoclonal antibody therapy is an important strategy in cancer therapeutics. Among the most promising characteristics of therapeutic targets are those that modulate the growth and survival of malignant neoplasms and their sensitivity to anticancer therapies. The insulin-like growth factor-I receptor (IGF-IR) is overexpressed in many types of solid and hematopoietic malignancies, and has been implicated as a principal cause of heightened proliferative and survival signaling. IGF-IR has also been shown to confer resistance to cytotoxic, hormonal, and targeted therapies, suggesting that therapeutics targeting IGF-IR may be effective against a broad range of malignancies. IMC-A12 (ImClone Systems Incorporated), a fully human monoclonal IgG1 antibody that binds with high affinity to the IGF-IR, inhibits ligand-dependent receptor activation and downstream signaling. IMC-A12 also mediates robust internalization and degradation of the IGF-IR. In human tumor xenograft models, IGF-IR blockade by IMC-A12 results in rapid and profound growth inhibition of cancers of the breast, lung, colon, and pancreas, and many other neoplasms. Although promising single-agent activity has been observed, the most impressive effects of targeting the IGF-IR with IMC-A12 have been noted when this agent was combined with cytotoxic agents or other targeted therapeutics. The results with IMC-A12 to date suggest that it may be an effective therapeutic in a diverse array of oncologic indications.

  14. Development and Characterization of Biphasic Hydroxyapatite/β-TCP Cements.

    Science.gov (United States)

    Gallinetti, Sara; Canal, Cristina; Ginebra, Maria-Pau; Ferreira, J

    2014-04-01

    Biphasic calcium phosphate bioceramics composed of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) have relevant properties as synthetic bone grafts, such as tunable resorption, bioactivity, and intrinsic osteoinduction. However, they have some limitations associated to their condition of high-temperature ceramics. In this work self-setting Biphasic Calcium Phosphate Cements (BCPCs) with different HA/β-TCP ratios were obtained from self-setting α-TCP/β-TCP pastes. The strategy used allowed synthesizing BCPCs with modulated composition, compressive strength, and specific surface area. Due to its higher solubility, α-TCP was fully hydrolyzed to a calcium-deficient HA (CDHA), whereas β-TCP remained unreacted and completely embedded in the CDHA matrix. Increasing amounts of the non-reacting β-TCP phase resulted in a linear decrease of the compressive strength, in association to the decreasing amount of precipitated HA crystals, which are responsible for the mechanical consolidation of apatitic cements. Ca(2+) release and degradation in acidic medium was similar in all the BCPCs within the timeframe studied, although differences might be expected in longer term studies once β-TCP, the more soluble phase was exposed to the surrounding media.

  15. Biphasic Chromatin Structure and FISH Signals Reflect Intranuclear Order

    Directory of Open Access Journals (Sweden)

    Jyoti P. Chaudhuri

    2005-01-01

    Full Text Available Background and Aim: One of the two parental allelic genes may selectively be expressed, regulated by imprinting, X-inactivation or by other less known mechanisms. This study aims to reflect on such genetic mechanisms. Materials and Methods: Slides from short term cultures or direct smears of blood, bone marrow and amniotic fluids were hybridized with FISH probes singly, combined or sequentially. Two to three hundred cells were examined from each preparation. Results and Aignificance: A small number of cells (up to about 5%, more frequent in leukemia cases, showed the twin features: (1 nuclei with biphasic chromatin, one part decondensed and the other condensed; and (2 homologous FISH signals distributed equitably in those two regions. The biphasic chromatin structure with equitable distribution of the homologous FISH signals may correspond to the two sets of chromosomes, supporting observations on ploidywise intranuclear order. The decondensed chromatin may relate to enhanced transcriptions or advanced replications. Conclusions: Transcriptions of only one of the two parental genomes cause allelic exclusion. Genomes may switch with alternating monoallelic expression of biallelic genes as an efficient genetic mechanism. If genomes fail to switch, allelic exclusion may lead to malignancy. Similarly, a genome-wide monoallelic replication may tilt the balance of heterozygosity resulting in aneusomy, initiating early events in malignant transformation and in predicting cancer mortality.

  16. New ways of insulin delivery.

    Science.gov (United States)

    Heinemann, L

    2011-02-01

    The predominant number of papers published from the middle of 2009 to the middle of 2010 about alternative routes of insulin administration (ARIA) were still about inhaled insulin. Long-term experience with Exubera was the topic of a number of publications that are also of relevance for inhaled insulin in general. The clinical trials performed with AIR insulin by Eli Lilly were published in a supplement issue of one diabetes technology journal and most of these will be presented. A number of other publications (also one in a high ranked journal) about their inhaled insulin were from another company: MannKind. The driving force behind Technosphere insulin (TI) - which is the only one still in clinical development - is Al Mann; he has put a lot of his personal fortune in this development. We will know the opinion of the regulatory authorities about TI in the near future; however, I am personally relatively confident that the Food and Drug Administration will provide TI with market approval. The more critical question for me is: will diabetologists and patients jump on this product once it becomes commercially available? Will it become a commercial success? In view of many negative feelings in the scientific community about inhaled insulin, it might be of help that MannKind publish their studies with TI systematically. Acknowledging being a believer in this route of insulin administration myself, one has to state that Exubera and AIR insulin had not offered profound advantages in terms of pharmacokinetic (PK) and pharmacodynamic (PD) properties in comparison with subcutaneously (SC) applied regular human insulin (RHI) and rapid-acting insulin analogues. The time-action profiles of these inhaled insulins were more or less comparable with that of rapid-acting insulin analogues. This is clearly different with TI which exhibits a strong metabolic effect shortly after application and a rapid decline in the metabolic effect thereafter; probably the duration of action is

  17. Dauricine inhibits insulin-like growth factor-Ⅰ-induced hypoxia inducible factor 1α protein accumulation and vascular endothelial growth factor expression in human breast cancer cells

    Institute of Scientific and Technical Information of China (English)

    Xu-dong TANG; Xin ZHOU; Ke-yuan ZHOU

    2009-01-01

    Aim: To investigate the effects of dauricine (Dau) on insulin-like growth factor-Ⅰ (IGF-Ⅰ)-induced hypoxia inducible factor 1α (HIF-1α) and vascular endothelial growth factor (VEGF) expression in human breast cancer cells (MCF-7).Methods: Serum-starved MCF-7 cells were pretreated for 1 h with different concentrations of Dau, followed by incubation with IGF-Ⅰ for 6 h. HIF-1α and VEGF protein expression levels were analyzed by Western blotting and ELISA, respectively.HIF-1α and VEGF mRNA levels were determined by real-time PCR. In vitro angiogenesis was observed via the human umbilical vein endothelial cell (HUVEC) tube formation assay. An in vitro invasion assay on HUVECs was performed.Results: Dau significantly inhibited IGF-Ⅰ-induced HIF-1α protein expression but had no effect on HIF-1α mRNA expression. However, Dau remarkably suppressed VEGF expression at both protein and mRNA levels in response to IGF-Ⅰ.Mechanistically, Dau suppressed IGF-Ⅰ-induced HIF-1α and VEGF protein expression mainly by blocking the activation of PI-3K/AKT/mTOR signaling pathway. In addition, Dan reduced IGF-Ⅰ-induced HIF-1α protein accumulation by inhibiting its synthesis as well as by promoting its degradation. Functionally, Dau inhibited angiogenesis in vitro. Moreover, Dau had a direct effect on IGF-Ⅰ-induced invasion of HUVECs.Conclusion: Dau inhibits human breast cancer angiogenesis by suppressing HIF-1α protein accumulation and VEGF expression, which may provide a novel potential mechanism for the anticancer activities of Dau in human breast cancer.

  18. The effect of exercise on the absorption of inhaled human insulin via the AERx(R) iDMS in people with type 1 diabetes

    DEFF Research Database (Denmark)

    Petersen, Astrid Heide; Kohler, G; Korsatko, S

    2007-01-01

    OBJECTIVE - This study investigated the effect of moderate exercise on the absorption of inhaled insulin via the AERx(R) insulin Diabetes Management System (iDMS). RESEARCH DESIGN AND METHODS - In this randomized, open-label, 4-period cross-over, glucose clamp study 23 non-smoking subjects...

  19. Studies of relationships between variation of the human G protein-coupled receptor 40 Gene and Type 2 diabetes and insulin release

    DEFF Research Database (Denmark)

    Hamid, Y H; Vissing, H; Holst, B

    2005-01-01

    -aged subjects from the Inter99 cohort showed no significant differences in oral glucose tolerance test (OGTT)-derived estimates of insulin release between carriers of various GPR40 genotypes. CONCLUSIONS: Variations in the coding region of GPR40 do not appear to be associated with Type 2 diabetes or insulin...

  20. Randomized trial on the effects of a 7-d low-glycemic diet and exercise intervention on insulin resistance in older obese humans

    DEFF Research Database (Denmark)

    Solomon, Thomas; Haus, Jacob M; Kelly, Karen R

    2009-01-01

    The optimal combination of diet and exercise that produces the greatest reversal of obesity-related insulin resistance is unknown.......The optimal combination of diet and exercise that produces the greatest reversal of obesity-related insulin resistance is unknown....

  1. Enterovirus infection of human islets of Langerhans affects β-cell function resulting in disintegrated islets, decreased glucose stimulated insulin secretion and loss of Golgi structure

    NARCIS (Netherlands)

    Hodik, M; Skog, O; Lukinius, A; Isaza-Correa, J M; Kuipers, J; Giepmans, B N G; Frisk, G

    2016-01-01

    AIMS/HYPOTHESIS: In type 1 diabetes (T1D), most insulin-producing β cells are destroyed, but the trigger is unknown. One of the possible triggers is a virus infection and the aim of this study was to test if enterovirus infection affects glucose stimulated insulin secretion and the effect of virus r

  2. Selective insulin resistance in hepatocyte senescence

    Energy Technology Data Exchange (ETDEWEB)

    Aravinthan, Aloysious [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Challis, Benjamin [Institute of Metabolic Sciences, University of Cambridge, Cambridge (United Kingdom); Shannon, Nicholas [Cancer Research UK Cambridge Institute, Cambridge (United Kingdom); Hoare, Matthew [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Cancer Research UK Cambridge Institute, Cambridge (United Kingdom); Heaney, Judith [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Foundation for Liver Research, Institute of Hepatology, London (United Kingdom); Alexander, Graeme J.M., E-mail: gja1000@doctors.org.uk [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom)

    2015-02-01

    Insulin resistance has been described in association with chronic liver disease for decades. Hepatocyte senescence has been demonstrated in chronic liver disease and as many as 80% of hepatocytes show a senescent phenotype in advanced liver disease. The aim of this study was to understand the role of hepatocyte senescence in the development of insulin resistance. Senescence was induced in HepG2 cells via oxidative stress. The insulin metabolic pathway was studied in control and senescent cells following insulin stimulation. GLUT2 and GLUT4 expressions were studied in HepG2 cells and human liver tissue. Further, GLUT2 and GLUT4 expressions were studied in three independent chronic liver disease cohorts. Signalling impairment distal to Akt in phosphorylation of AS160 and FoxO1 was evident in senescent HepG2 cells. Persistent nuclear localisation of FoxO1 was demonstrated in senescent cells despite insulin stimulation. Increased GLUT4 and decreased GLUT2 expressions were evident in senescent cells, human cirrhotic liver tissue and publically available liver disease datasets. Changes in GLUT expressions were associated with a poor clinical prognosis. In conclusion, selective insulin resistance is evident in senescent HepG2 cells and changes in GLUT expressions can be used as surrogate markers of hepatocyte senescence. - Highlights: • Senescent hepatocytes demonstrate selective insulin resistance. • GLUT changes act as markers of hepatocyte senescence and have prognostic value. • Study offers insight into long noticed intimacy of cirrhosis and insulin resistance.

  3. Evaluation of Biphasic Culture System for Mycobacterial Isolation from the Sputum of Patients with Pulmonary Tuberculosis

    Directory of Open Access Journals (Sweden)

    Ghatole M

    2005-01-01

    Full Text Available Mycobacterial diseases continue to cause high morbidity and mortality. Isolation, identification and sensitivity testing form the backbone of laboratory investigations. M. tuberculosis isolation needs 6-8 weeks on conventional egg containing media. For rapid isolation various methods have been evaluated. We evaluated biphasic system (Middlebrook 7H11 agar slant + Middlebrook 9H broth in comparison with Lowenstein - Jensen (LJ medium. In smear positive cases biphasic system showed the recovery rate of 97.05% as against 79.41% on LJ on incubation for 21± 4.44 and 28±3.76 days respectively. In smear negative and culture positive cases biphasic system and LJ showed isolation rates of 91.66% and 66.6% after 36±3.44 and 41± 4.09 days respectively. Biphasic system showed lower contamination rate (1.33%. Biphasic medium is superior to LJ medium in isolation of M. tuberculosis .

  4. Intranasal insulin therapy

    DEFF Research Database (Denmark)

    Hilsted, J; Madsbad, S; Hvidberg, A;

    1995-01-01

    To evaluate metabolic control and safety parameters (hypoglycaemia frequency and nasal mucosa physiology), 31 insulin-dependent diabetic patients were treated with intranasal insulin at mealtimes for 1 month and with subcutaneous fast-acting insulin at meals for another month in an open, crossover...... randomized trial. During both treatment periods the patients were treated with intermediate-acting insulin at bedtime. Six of the patients were withdrawn from the study during intranasal insulin therapy due to metabolic dysregulation. Serum insulin concentrations increased more rapidly and decreased more...... quickly during intranasal as compared with subcutaneous insulin administration. Metabolic control deteriorated, as assessed by haemoglobin A1c concentrations, slightly but significantly after intranasal as compared with subcutaneous insulin therapy. The bioavailability of intranasally applied insulin...

  5. Safety and Efficacy of Modern Insulin Analogues

    Directory of Open Access Journals (Sweden)

    Hye Jin Yoo

    2013-06-01

    Full Text Available BackgroundA1chieve® was a noninterventional study evaluating the clinical safety and efficacy of biphasic insulin aspart 30, insulin detemir, and insulin aspart.MethodsKorean type 2 diabetes patients who have not been treated with the study insulin or have started it within 4 weeks before enrollment were eligible for the study. The patient selection and the choice of regimen were at the discretion of the physician. The safety and efficacy information was collected from the subjects at baseline, week 12, and week 24. The number of serious adverse drug reactions (SADRs was the primary endpoint. The changes of clinical diabetic markers at week 12 and/or at week 24 compared to baseline were the secondary endpoints.ResultsOut of 4,058 exposed patients, 3,003 completed the study. During the study period, three SADRs were reported in three patients (0.1%. No major hypoglycemic episodes were observed and the rate of minor hypoglycemic episodes marginally decreased during 24 weeks (from 2.77 to 2.42 events per patient-year. The overall quality of life score improved (from 66.7±15.9 to 72.5±13.5 while the mean body weight was slightly increased (0.6±3.0 kg. The 24-week reductions in glycated hemoglobin, fasting plasma glucose and postprandial plasma glucose were 1.6%±2.2%, 2.5±4.7 mmol/L, and 4.0±6.4 mmol/L, respectively.ConclusionThe studied regimens showed improvements in glycemic control with low incidence of SADRs, including no incidence of major hypoglycemic episodes in Korean patients with type 2 diabetes.

  6. Notch2 controls prolactin and insulin-like growth factor binding protein-1 expression in decidualizing human stromal cells of early pregnancy.

    Directory of Open Access Journals (Sweden)

    Gerlinde R Otti

    Full Text Available Decidualization, the transformation of the human uterine mucosa into the endometrium of pregnancy, is critical for successful implantation and embryonic development. However, key regulatory factors controlling differentiation of uterine stromal cells into hormone-secreting decidual cells have not been fully elucidated. Hence, we herein investigated the role of the Notch signaling pathway in human decidual stromal cells (HDSC isolated from early pregnancy samples. Immunofluorescence of first trimester decidual tissues revealed expression of Notch2 receptor and its putative, membrane-anchored interaction partners Jagged1, Delta-like (DLL 1 and DLL4 in stromal cells whereas other Notch receptors and ligands were absent from these cells. During in vitro differentiation with estrogen/progesterone (E2P4 and/or cyclic adenosine monophosphate (cAMP HDSC constitutively expressed Notch2 and weakly downregulated Jagged1 mRNA and protein, measured by quantitative PCR (qPCR and Western blotting, respectively. However, increased levels of DLL1 and DLL4 were observed in the decidualizing cultures. Transfection of a Notch luciferase reporter and qPCR of the Notch target gene hairy and enhancer of split 1 (HES1 revealed an induction of canonical Notch activity during in vitro differentiation. In contrast, treatment of HDSC with a chemical Notch/γ-secretase inhibitor decreased cAMP/E2P4-stimulated Notch luciferase activity, HES1 transcript levels and mRNA expression of the decidual marker genes prolactin (PRL and insulin-like growth factor binding protein 1 (IGFBP1. Similarly, siRNA-mediated gene silencing or antibody-mediated blocking of Notch2 diminished HES1, PRL and IGFBP1 mRNA levels as well as secreted PRL protein. In summary, the data suggest that canonical, Notch2-dependent signaling plays a role in human decidualization.

  7. Mathematical modeling and statistical analysis of calcium-regulated insulin granule exocytosis in ß-cells from mice and humans

    DEFF Research Database (Denmark)

    Pedersen, Morten Gram; Cortese, Giuliana; Eliasson, Lena

    2011-01-01

    on depolarization-evoked Ca2+-currents and corresponding capacitance measurements. Using a statistical mixed-effects model, we show that the data indicate that pool depletion is negligible in response to short depolarizations in mouse ß-cells. We then review mathematical models of granule dynamics and exocytosis...... in rodent ß-cells and present a mathematical description of Ca2+-evoked exocytosis in human ß-cells, which show clear differences to their rodent counterparts. The model suggests that L- and P/Q-type Ca2+-channels are involved to a similar degree in exocytosis during electrical activity in human ß-cells....

  8. Insulin Receptor Substrate 2 Is a Negative Regulator of Memory Formation

    Science.gov (United States)

    Irvine, Elaine E.; Drinkwater, Laura; Radwanska, Kasia; Al-Qassab, Hind; Smith, Mark A.; O'Brien, Melissa; Kielar, Catherine; Choudhury, Agharul I.; Krauss, Stefan; Cooper, Jonathan D.; Withers, Dominic J.; Giese, Karl Peter

    2011-01-01

    Insulin has been shown to impact on learning and memory in both humans and animals, but the downstream signaling mechanisms involved are poorly characterized. Insulin receptor substrate-2 (Irs2) is an adaptor protein that couples activation of insulin- and insulin-like growth factor-1 receptors to downstream signaling pathways. Here, we have…

  9. Changing the insulin receptor to possess insulin-like growth factor I ligand specificity

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, A.S.; Kjeldsen, T.; Wiberg, F.C.; Christensen, P.M.; Rasmussen, J.S.; Norris, K.; Moeller, K.B.; Moeller, N.P.H. (Biopharmaceuticals Div., Bagsvaerd (Denmark))

    1990-08-14

    To examine the role of the N-terminal part of the insulin-like growth factor I (IGF-I) receptor and insulin receptor in determining ligand specificity, the authors prepared an expression vector encoding a hybrid receptor where exon 1 (encoding the signal peptide and seven amino acids of the {alpha}-subunit), exon 2, and exon 3 of the insulin receptor were replaced with the corresponding IGF-I receptor cDNA (938 nucleotides). To allow direct quantitative comparison of the binding capabilities of this hybrid receptor with those of the human IGF-I receptor and the insulin receptor, all three receptors were expressed in baby hamster kidney (BHK) cells as soluble molecules and partially purified before characterization. The hybrid IGF-I/insulin receptor bound IGF-I with an affinity comparable to that of the wild-type IGF-I receptor. In contrast, the hybrid receptor no longer displayed high-affinity binding of insulin. These results directly demonstrate that it is possible to change the specificity of the insulin receptor to that of the IGF-I receptor and, furthermore, that the binding specificity for IGF-I is encoded within the nucleotide sequence from 135 to 938 of the IGF-I receptor cDNA. Since the hybrid receptor only bound insulin with low affinity, the insulin binding region is likely to be located within exons 2 and 3 of the insulin receptor.

  10. Severe insulin resistance secondary to insulin antibodies: successful treatment with the immunosuppressant MMF.

    Science.gov (United States)

    Segal, T; Webb, Ea; Viner, R; Pusey, C; Wild, G; Allgrove, J

    2008-06-01

    We have evaluated the use of the immunosuppressant mycophenolate mofetil (MMF) in the treatment of severe insulin resistance caused by neutralising anti-insulin antibodies in type 1 diabetes mellitus (T1DM). A 12-yr-old boy with a 5-month history of T1DM developed severe immunological insulin resistance secondary to human insulin antibodies. Various different treatment modalities, including lispro insulin, intravenous insulin, prednisolone and immunoabsorption, were tried, all without a sustained response to treatment. Although the introduction of the immunosuppressant MMF only resulted in a small reduction in haemoglobin A1c (from 10.9 to 9.8%), it did result in a significant reduction in insulin requirements from 6000 to 250 U/d (75 to 3.1 U/kg/d), disappearance of the severe nocturnal hypoglycaemia associated with high titres of insulin antibodies and a reduction in the level of these antibodies from 34.6 to 2.7 mg/dL. MMF may be considered as a means of immunosuppression in patients with markedly raised insulin antibodies whose diabetes cannot be controlled with insulin alone.

  11. A novel unidirectional cross-talk from the insulin-like growth factor-I receptor to leptin receptor in human breast cancer cells.

    Science.gov (United States)

    Ozbay, Tuba; Nahta, Rita

    2008-06-01

    Obesity is a major risk factor for the development and progression of breast cancer. Increased circulating levels of the obesity-associated hormones leptin and insulin-like growth factor-I (IGF-I) and overexpression of the leptin receptor (Ob-R) and IGF-I receptor (IGF-IR) have been detected in a majority of breast cancer cases and during obesity. Due to correlations between increased leptin, Ob-R, IGF-I, and IGF-IR in breast cancer, we hypothesized that molecular interactions may exist between these two signaling pathways. Coimmunoprecipitation and immunoblotting showed that IGF-IR and Ob-R interact in the breast cancer cell lines MDA-MB-231, MCF7, BT474, and SKBR3. Stimulation of cells with IGF-I promoted Ob-R phosphorylation, which was blocked by IGF-IR kinase inhibition. In addition, IGF-I activated downstream signaling molecules in the leptin receptor and IGF-IR pathways. In contrast to IGF-I, leptin did not induce phosphorylation of IGF-IR, indicating that receptor cross-signaling is unidirectional, occurring from IGF-IR to Ob-R. Our results show, for the first time, a novel interaction and cross-talk between the IGF-I and leptin receptors in human breast cancer cells.

  12. The role of copper(II) and zinc(II) in the degradation of human and murine IAPP by