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Geremia B Bolli - One of the best experts on this subject based on the ideXlab platform.

  • short term effects of the long acting Insulin Analog detemir and human Insulin on plasma levels of Insulin like growth factor i and its binding proteins in humans
    The Journal of Clinical Endocrinology and Metabolism, 2009
    Co-Authors: Francesca Porcellati, Geremia B Bolli, Paolo Rossetti, Anna Marinelli Andreoli, Paola Candeloro, Paola Lucidi, Patrizia Cioli, E Ghigo, Carmine G Fanelli
    Abstract:

    Objective: The objective of the study was to compare responses of plasma levels of IGF-I and IGF binding proteins (IGFBP-1 and IGFBP-3) induced by human regular Insulin (HI) and the long-acting Insulin Analog detemir (IDet) at doses equivalent with respect to the glucose-lowering effect. Experimental Design: Ten nondiabetic subjects (six males, four females; age, 36 ± 7 yr; body mass index, 22.9 ± 2.6 kg/m2) were studied on four randomized occasions with iv infusion of IDet (2 mU/kg · min for 4 h, followed by 4 mU/kg · min for 1 h) or HI (1 mU/kg · min for 4 h, followed by 2 mU/kg · min for 1 h) in euglycemia [plasma glucose (PG), 90 mg/dl] or during stepped hypoglycemia (PG, 90, 78, 66, 54, and 42 mg/dl). Results: PG was maintained at preselected plateaus, without any significant difference between IDet and HI (P > 0.2). Plasma Insulin concentrations were on average approximately nine times greater with IDet than HI (749 ± 52 vs. 83 ± 19 μU/ml, respectively). Plasma IGF-I concentrations did not change fr...

  • different brain responses to hypoglycemia induced by equipotent doses of the long acting Insulin Analog detemir and human regular Insulin in humans
    Diabetes, 2008
    Co-Authors: Paolo Rossetti, Francesca Porcellati, Geremia B Bolli, Natalia Busciantella Ricci, Paola Candeloro, Patrizia Cioli, Carmine G Fanelli
    Abstract:

    OBJECTIVE— The acylated long-acting Insulin Analog detemir is more lipophilic than human Insulin and likely crosses the blood-to-brain barrier more easily than does human Insulin. The aim of these studies was to assess the brain/hypothalamus responses to euglycemia and hypoglycemia in humans during intravenous infusion of equipotent doses of detemir and human Insulin. RESEARCH DESIGN AND METHODS— Ten normal, nondiabetic subjects (six men, age 36±7 years, and BMI 22.9±2.6 kg/m 2 ) were studied on four occasions at random during intravenous infusion of either detemir or human Insulin in euglycemia (plasma glucose 90 mg/dl) or during stepped hypoglycemia (plasma glucose 90, 78, 66, 54, and 42 mg/dl steps). RESULTS— Plasma counterregulatory hormone response to hypoglycemia did not differ between detemir and human Insulin. The glycemic thresholds for adrenergic symptoms were higher with detemir (51 ± 7.7 mg/dl) versus human Insulin (56 ± 7.8 mg/dl) ( P = 0.029). However, maximal responses were greater with detemir versus human Insulin for adrenergic (3 ± 2.5 vs. 2.4 ± 1.8) and neuroglycopenic (4 ± 3.9 vs. 2.7±2.5) symptoms (score, P P = 0.031), and cognitive function was more deteriorated with detemir versus human Insulin ( P CONCLUSIONS— Compared with human Insulin, responses to hypoglycemia with detemir resulted in higher glycemic thresholds for adrenergic symptoms and greater maximal responses for adrenergic and neuroglycopenic symptoms, with an earlier and greater impairment of cognitive function. Additional studies are needed to establish the effects of detemir on responses to hypoglycemia in subjects with diabetes.

  • pharmacokinetics and pharmacodynamics of the long acting Insulin Analog glargine after 1 week of use compared with its first administration in subjects with type 1 diabetes
    Diabetes Care, 2007
    Co-Authors: Francesca Porcellati, Elisabetta Torlone, S Pampanelli, Geremia B Bolli, Paolo Rossetti, Natalia Busciantella Ricci, Susana Hernandez Campos, Anna Marinelli Andreoli, Carmine G Fanelli
    Abstract:

    Pharmacokinetics and pharmacodynamics of the long-acting Insulin Analog glargine (1) are superior to those of Insulin NPH (2–9). In the clinical setting, this translates into lower risk of nocturnal hypoglycemia (10–13), lower A1C (provided that appropriate requirements of mealtime rapid-acting Insulin are met) (11–13), and the convenience of once (12), compared with multiple, administration of NPH (14). However, no study has examined subjects after several days of its use versus the “first” subcutaneous injection. The present studies were undertaken to establish the pharmacokinetics and pharmacodynamics of Insulin glargine in type 1 diabetes after 1 week of its once-daily use and to compare it with those observed after the first injection. After institutional review board approval, 20 type 1 diabetic subjects (12 male subjects, age 31 ± 2 years, type 1 diabetes duration 11 ± 1 years, BMI 23.3 ± 0.4 kg/m2, fasting plasma C-peptide <0.02 nmol/l, and A1C 7.1 ± 0.2%) using NPH as basal Insulin and human regular Insulin ( n = 7) or lispro Insulin ( n = 13), in combination with NPH at each meal as previously described (14), were studied. During a 2-week run-in period, subjects continued their previous model of Insulin therapy, i.e., human regular Insulin or the rapid-acting Insulin Analog lispro at breakfast, lunch, and dinner and NPH Insulin at bedtime, or even at each meal in those patients ( n = 13) who used lispro (14). Thereafter, subjects were studied with the glucose clamp technique after subcutaneous injection of 0.3 units/kg Insulin glargine as previously described (6). Subjects …

  • pharmacokinetics and pharmacodynamics of subcutaneous injection of long acting human Insulin Analog glargine nph Insulin and ultralente human Insulin and continuous subcutaneous infusion of Insulin lispro
    Diabetes, 2000
    Co-Authors: Marino Lepore, S Pampanelli, Carmine G Fanelli, Francesca Porcellati, L Bartocci, A Di Vincenzo, Cristina Cordoni, P Brunetti, Geremia B Bolli
    Abstract:

    To compare the pharmacokinetics/dynamics of the long-acting Insulin Analog glargine with NPH, ultralente, and continuous subcutaneous (SC) infusion of Insulin lispro (continuous subcutaneous Insulin infusion [CSII]), 20 C-peptide-negative type 1 diabetic patients were studied on four occasions during an isoglycemic 24-h clamp. Patients received SC injection of either 0.3 U/kg glargine or NPH Insulin (random sequence, crossover design). On two subsequent occasions, they received either an SC injection of ultralente (0.3 U/kg) or CSII (0.3 U x kg(-1) x 24 h(-1)) (random sequence, crossover design). After SC Insulin injection or CSII, intravenous (IV) Insulin was tapered, and glucose was infused to clamp plasma glucose at 130 mg/dl for 24 h. Onset of action (defined as reduction of IV Insulin >50%) was earlier with NPH (0.8 +/- 0.2 h), CSII (0.5 +/- 0.1 h), and ultralente (1 +/- 0.2 h) versus glargine (1.5 +/- 0.3 h) (P 150 mg/dl) occurred later with glargine (22 +/- 4 h) than with NPH (14 +/- 3 h) (P < 0.05) but was similar with ultralente (20 +/- 6 h). NPH and ultralente exhibited a peak concentration and action (at 4.5 +/- 0.5 and 10.1 +/- 1 h, respectively) followed by waning, whereas glargine had no peak but had a flat concentration/action profile mimicking CSII. Interindividual variability (calculated as differences in SD of plasma Insulin concentrations and glucose infusion rates in different treatments) was lower with glargine than with NPH and ultralente (P < 0.05) but was similar with glargine and CSII (NS). In conclusion, NPH and ultralente are both peak Insulins. Duration of action of ultralente is greater, but intersubject variability is also greater than that of NPH. Glargine is a peakless Insulin, it lasts nearly 24 h, it has lower intersubject variability than NPH and ultralente, and it closely mimics CSII, the gold standard of basal Insulin replacement.

  • long term intensive treatment of type 1 diabetes with the short acting Insulin Analog lispro in variable combination with nph Insulin at mealtime
    Diabetes Care, 1999
    Co-Authors: Claudia Lalli, P Del Sindaco, Elisabetta Torlone, P Compagnucci, M G Cartechini, S Pampanelli, L Bartocci, M Ciofetta, Paolo Brunetti, Geremia B Bolli
    Abstract:

    OBJECTIVE: To establish whether the short-acting Insulin Analog lispro can be successfully implemented in long-term intensive Insulin therapy in type 1 diabetes, and if so, what its effects are on glycemic control and frequency and awareness of hypoglycemia. RESEARCH DESIGN AND METHODS: We randomized 56 type 1 diabetic patients to treatment with either lispro (n = 28) or human regular Insulin (Hum-R; n = 28) as mealtime Insulin for 1 year (open design, parallel groups). Lispro was injected at mealtime and Hum-R was given 10-40 min before meals (bedtime NPH was continued on both occasions). With lispro, NPH was added at breakfast (approximately 70/30), lunch (approximately 60/40), and supper (approximately 80/20) (mixing percentage of lispro/NPH) to optimize premeal and bedtime blood glucose. RESULTS: Total daily Insulin units were no different in the two treatment groups, but with lispro approximately 30% less short-acting Insulin at meals and approximately 30% more NPH was needed versus Hum-R (P

Michael A Weiss - One of the best experts on this subject based on the ideXlab platform.

  • design of an Insulin Analog with enhanced receptor binding selectivity rationale structure and therapeutic implications
    Journal of Biological Chemistry, 2009
    Co-Authors: Ming Zhao, Nelson B Phillips, Faramarz Ismailbeigi, Zhuli Wan, Linda Whittaker, Panayotis G Katsoyannis, Jonathan Whittaker, Michael A Weiss
    Abstract:

    Insulin binds with high affinity to the Insulin receptor (IR) and with low affinity to the type 1 Insulin-like growth factor (IGF) receptor (IGFR). Such cross-binding, which reflects homologies within the Insulin-IGF signaling system, is of clinical interest in relation to the association between hyperInsulinemia and colorectal cancer. Here, we employ nonstandard mutagenesis to design an Insulin Analog with enhanced affinity for the IR but reduced affinity for the IGFR. Unnatural amino acids were introduced by chemical synthesis at the N- and C-capping positions of a recognition α-helix (residues A1 and A8). These sites adjoin the hormone-receptor interface as indicated by photocross-linking studies. Specificity is enhanced more than 3-fold on the following: (i) substitution of GlyA1 by d-Ala or d-Leu, and (ii) substitution of ThrA8 by diaminobutyric acid (Dab). The crystal structure of [d-AlaA1,DabA8]Insulin, as determined within a T6 zinc hexamer to a resolution of 1.35 A, is essentially identical to that of human Insulin. The nonstandard side chains project into solvent at the edge of a conserved receptor-binding surface shared by Insulin and IGF-I. Our results demonstrate that modifications at this edge discriminate between IR and IGFR. Because hyperInsulinemia is typically characterized by a 3-fold increase in integrated postprandial Insulin concentrations, we envisage that such Insulin Analogs may facilitate studies of the initiation and progression of cancer in animal models. Future development of clinical Analogs lacking significant IGFR cross-binding may enhance the safety of Insulin replacement therapy in patients with type 2 diabetes mellitus at increased risk of colorectal cancer.

  • design of an active ultrastable single chain Insulin Analog synthesis structure and therapeutic implications
    Journal of Biological Chemistry, 2008
    Co-Authors: Qing Xin Hua, Nelson B Phillips, Satoe H Nakagawa, Wenhua Jia, Kun Huang, Michael A Weiss
    Abstract:

    Single-chain Insulin (SCI) Analogs provide insight into the inter-relation of hormone structure, function, and dynamics. Although compatible with wild-type structure, short connecting segments (<3 residues) prevent induced fit upon receptor binding and so are essentially without biological activity. Substantial but incomplete activity can be regained with increasing linker length. Here, we describe the design, structure, and function of a single-chain Insulin Analog (SCI-57) containing a 6-residue linker (GGGPRR). Native receptor-binding affinity (130 +/- 8% relative to the wild type) is achieved as hindrance by the linker is offset by favorable substitutions in the Insulin moiety. The thermodynamic stability of SCI-57 is markedly increased (DeltaDeltaG(u) = 0.7 +/- 0.1 kcal/mol relative to the corresponding two-chain Analog and 1.9 +/- 0.1 kcal/mol relative to wild-type Insulin). Analysis of inter-residue nuclear Overhauser effects demonstrates that a native-like fold is maintained in solution. Surprisingly, the glycine-rich connecting segment folds against the Insulin moiety: its central Pro contacts Val(A3) at the edge of the hydrophobic core, whereas the final Arg extends the A1-A8 alpha-helix. Comparison between SCI-57 and its parent two-chain Analog reveals striking enhancement of multiple native-like nuclear Overhauser effects within the tethered protein. These contacts are consistent with wild-type crystal structures but are ordinarily attenuated in NMR spectra of two-chain Analogs, presumably due to conformational fluctuations. Linker-specific damping of fluctuations provides evidence for the intrinsic flexibility of an Insulin monomer. In addition to their biophysical interest, ultrastable SCIs may enhance the safety and efficacy of Insulin replacement therapy in the developing world.

  • design of an active ultrastable single chain Insulin Analog synthesis structure and therapeutic implications
    Journal of Biological Chemistry, 2008
    Co-Authors: Qing Xin Hua, Nelson B Phillips, Satoe H Nakagawa, Wenhua Jia, Kun Huang, Michael A Weiss
    Abstract:

    Single-chain Insulin (SCI) Analogs provide insight into the inter-relation of hormone structure, function, and dynamics. Although compatible with wild-type structure, short connecting segments (<3 residues) prevent induced fit upon receptor binding and so are essentially without biological activity. Substantial but incomplete activity can be regained with increasing linker length. Here, we describe the design, structure, and function of a single-chain Insulin Analog (SCI-57) containing a 6-residue linker (GGGPRR). Native receptor-binding affinity (130 ± 8% relative to the wild type) is achieved as hindrance by the linker is offset by favorable substitutions in the Insulin moiety. The thermodynamic stability of SCI-57 is markedly increased (ΔΔGu = 0.7 ± 0.1 kcal/mol relative to the corresponding two-chain Analog and 1.9 ± 0.1 kcal/mol relative to wild-type Insulin). Analysis of inter-residue nuclear Overhauser effects demonstrates that a native-like fold is maintained in solution. Surprisingly, the glycine-rich connecting segment folds against the Insulin moiety: its central Pro contacts ValA3 at the edge of the hydrophobic core, whereas the final Arg extends the A1-A8 α-helix. Comparison between SCI-57 and its parent two-chain Analog reveals striking enhancement of multiple native-like nuclear Overhauser effects within the tethered protein. These contacts are consistent with wild-type crystal structures but are ordinarily attenuated in NMR spectra of two-chain Analogs, presumably due to conformational fluctuations. Linker-specific damping of fluctuations provides evidence for the intrinsic flexibility of an Insulin monomer. In addition to their biophysical interest, ultrastable SCIs may enhance the safety and efficacy of Insulin replacement therapy in the developing world.

  • design of an active ultrastable single chain Insulin Analog synthesis structure and therapeutic implications
    Journal of Biological Chemistry, 2008
    Co-Authors: Qing Xin Hua, Nelson B Phillips, Satoe H Nakagawa, Wenhua Jia, Kun Huang, Michael A Weiss
    Abstract:

    Single-chain Insulin (SCI) Analogs provide insight into the inter-relation of hormone structure, function, and dynamics. Although compatible with wild-type structure, short connecting segments (

Nelson B Phillips - One of the best experts on this subject based on the ideXlab platform.

  • solution structure of an ultra stable single chain Insulin Analog connects protein dynamics to a novel mechanism of receptor binding
    Journal of Biological Chemistry, 2018
    Co-Authors: Michael D Glidden, Yanwu Yang, Nicholas A Smith, Nelson B Phillips, Kelley Carr, Nalinda P Wickramasinghe, Faramarz Ismailbeigi, Michael C Lawrence, Brian J Smith
    Abstract:

    Domain-minimized Insulin receptors (IRs) have enabled crystallographic analysis of Insulin-bound "micro-receptors." In such structures, the C-terminal segment of the Insulin B chain inserts between conserved IR domains, unmasking an invariant receptor-binding surface that spans both Insulin A and B chains. This "open" conformation not only rationalizes the inactivity of single-chain Insulin (SCI) Analogs (in which the A and B chains are directly linked), but also suggests that connecting (C) domains of sufficient length will bind the IR. Here, we report the high-resolution solution structure and dynamics of such an active SCI. The hormone's closed-to-open transition is foreshadowed by segmental flexibility in the native state as probed by heteronuclear NMR spectroscopy and multiple conformer simulations of crystallographic protomers as described in the companion article. We propose a model of the SCI's IR-bound state based on molecular-dynamics simulations of a micro-receptor complex. In this model, a loop defined by the SCI's B and C domains encircles the C-terminal segment of the IR α-subunit. This binding mode predicts a conformational transition between an ultra-stable closed state (in the free hormone) and an active open state (on receptor binding). Optimization of this switch within an ultra-stable SCI promises to circumvent Insulin's complex global cold chain. The Analog's biphasic activity, which serendipitously resembles current premixed formulations of soluble Insulin and microcrystalline suspension, may be of particular utility in the developing world.

  • an ultra stable single chain Insulin Analog resists thermal inactivation and exhibits biological signaling duration equivalent to the native protein
    Journal of Biological Chemistry, 2018
    Co-Authors: Michael D Glidden, Nelson B Phillips, Kelley Carr, Nalinda P Wickramasinghe, Jonathan Whittaker, Khadijah Aldabbagh, Yen Shan Chen, Manijeh Phillips, Nischay Rege, Mamuni Swain
    Abstract:

    : Thermal degradation of Insulin complicates its delivery and use. Previous efforts to engineer ultra-stable Analogs were confounded by prolonged cellular signaling in vivo, of unclear safety and complicating mealtime therapy. We therefore sought an ultra-stable Analog whose potency and duration of action on intravenous bolus injection in diabetic rats are indistinguishable from wild-type (WT) Insulin. Here, we describe the structure, function, and stability of such an Analog, a 57-residue single-chain Insulin (SCI) with multiple acidic substitutions. Cell-based studies revealed native-like signaling properties with negligible mitogenic activity. Its crystal structure, determined as a novel zinc-free hexamer at 2.8 A, revealed a native Insulin fold with incomplete or absent electron density in the C domain; complementary NMR studies are described in the accompanying article. The stability of the Analog (ΔGU 5.0(±0.1) kcal/mol at 25 °C) was greater than that of WT Insulin (3.3(±0.1) kcal/mol). On gentle agitation, the SCI retained full activity for >140 days at 45 °C and >48 h at 75 °C. These findings indicate that marked resistance to thermal inactivation in vitro is compatible with native duration of activity in vivo Further, whereas WT Insulin forms large and heterogeneous aggregates above the standard 0.6 mm pharmaceutical strength, perturbing the pharmacokinetic properties of concentrated formulations, dynamic light scattering, and size-exclusion chromatography revealed only limited SCI self-assembly and aggregation in the concentration range 1-7 mm Such a combination of favorable biophysical and biological properties suggests that SCIs could provide a global therapeutic platform without a cold chain.

  • design of an Insulin Analog with enhanced receptor binding selectivity rationale structure and therapeutic implications
    Journal of Biological Chemistry, 2009
    Co-Authors: Ming Zhao, Nelson B Phillips, Faramarz Ismailbeigi, Zhuli Wan, Linda Whittaker, Panayotis G Katsoyannis, Jonathan Whittaker, Michael A Weiss
    Abstract:

    Insulin binds with high affinity to the Insulin receptor (IR) and with low affinity to the type 1 Insulin-like growth factor (IGF) receptor (IGFR). Such cross-binding, which reflects homologies within the Insulin-IGF signaling system, is of clinical interest in relation to the association between hyperInsulinemia and colorectal cancer. Here, we employ nonstandard mutagenesis to design an Insulin Analog with enhanced affinity for the IR but reduced affinity for the IGFR. Unnatural amino acids were introduced by chemical synthesis at the N- and C-capping positions of a recognition α-helix (residues A1 and A8). These sites adjoin the hormone-receptor interface as indicated by photocross-linking studies. Specificity is enhanced more than 3-fold on the following: (i) substitution of GlyA1 by d-Ala or d-Leu, and (ii) substitution of ThrA8 by diaminobutyric acid (Dab). The crystal structure of [d-AlaA1,DabA8]Insulin, as determined within a T6 zinc hexamer to a resolution of 1.35 A, is essentially identical to that of human Insulin. The nonstandard side chains project into solvent at the edge of a conserved receptor-binding surface shared by Insulin and IGF-I. Our results demonstrate that modifications at this edge discriminate between IR and IGFR. Because hyperInsulinemia is typically characterized by a 3-fold increase in integrated postprandial Insulin concentrations, we envisage that such Insulin Analogs may facilitate studies of the initiation and progression of cancer in animal models. Future development of clinical Analogs lacking significant IGFR cross-binding may enhance the safety of Insulin replacement therapy in patients with type 2 diabetes mellitus at increased risk of colorectal cancer.

  • design of an active ultrastable single chain Insulin Analog synthesis structure and therapeutic implications
    Journal of Biological Chemistry, 2008
    Co-Authors: Qing Xin Hua, Nelson B Phillips, Satoe H Nakagawa, Wenhua Jia, Kun Huang, Michael A Weiss
    Abstract:

    Single-chain Insulin (SCI) Analogs provide insight into the inter-relation of hormone structure, function, and dynamics. Although compatible with wild-type structure, short connecting segments (<3 residues) prevent induced fit upon receptor binding and so are essentially without biological activity. Substantial but incomplete activity can be regained with increasing linker length. Here, we describe the design, structure, and function of a single-chain Insulin Analog (SCI-57) containing a 6-residue linker (GGGPRR). Native receptor-binding affinity (130 +/- 8% relative to the wild type) is achieved as hindrance by the linker is offset by favorable substitutions in the Insulin moiety. The thermodynamic stability of SCI-57 is markedly increased (DeltaDeltaG(u) = 0.7 +/- 0.1 kcal/mol relative to the corresponding two-chain Analog and 1.9 +/- 0.1 kcal/mol relative to wild-type Insulin). Analysis of inter-residue nuclear Overhauser effects demonstrates that a native-like fold is maintained in solution. Surprisingly, the glycine-rich connecting segment folds against the Insulin moiety: its central Pro contacts Val(A3) at the edge of the hydrophobic core, whereas the final Arg extends the A1-A8 alpha-helix. Comparison between SCI-57 and its parent two-chain Analog reveals striking enhancement of multiple native-like nuclear Overhauser effects within the tethered protein. These contacts are consistent with wild-type crystal structures but are ordinarily attenuated in NMR spectra of two-chain Analogs, presumably due to conformational fluctuations. Linker-specific damping of fluctuations provides evidence for the intrinsic flexibility of an Insulin monomer. In addition to their biophysical interest, ultrastable SCIs may enhance the safety and efficacy of Insulin replacement therapy in the developing world.

  • design of an active ultrastable single chain Insulin Analog synthesis structure and therapeutic implications
    Journal of Biological Chemistry, 2008
    Co-Authors: Qing Xin Hua, Nelson B Phillips, Satoe H Nakagawa, Wenhua Jia, Kun Huang, Michael A Weiss
    Abstract:

    Single-chain Insulin (SCI) Analogs provide insight into the inter-relation of hormone structure, function, and dynamics. Although compatible with wild-type structure, short connecting segments (<3 residues) prevent induced fit upon receptor binding and so are essentially without biological activity. Substantial but incomplete activity can be regained with increasing linker length. Here, we describe the design, structure, and function of a single-chain Insulin Analog (SCI-57) containing a 6-residue linker (GGGPRR). Native receptor-binding affinity (130 ± 8% relative to the wild type) is achieved as hindrance by the linker is offset by favorable substitutions in the Insulin moiety. The thermodynamic stability of SCI-57 is markedly increased (ΔΔGu = 0.7 ± 0.1 kcal/mol relative to the corresponding two-chain Analog and 1.9 ± 0.1 kcal/mol relative to wild-type Insulin). Analysis of inter-residue nuclear Overhauser effects demonstrates that a native-like fold is maintained in solution. Surprisingly, the glycine-rich connecting segment folds against the Insulin moiety: its central Pro contacts ValA3 at the edge of the hydrophobic core, whereas the final Arg extends the A1-A8 α-helix. Comparison between SCI-57 and its parent two-chain Analog reveals striking enhancement of multiple native-like nuclear Overhauser effects within the tethered protein. These contacts are consistent with wild-type crystal structures but are ordinarily attenuated in NMR spectra of two-chain Analogs, presumably due to conformational fluctuations. Linker-specific damping of fluctuations provides evidence for the intrinsic flexibility of an Insulin monomer. In addition to their biophysical interest, ultrastable SCIs may enhance the safety and efficacy of Insulin replacement therapy in the developing world.

Carmine G Fanelli - One of the best experts on this subject based on the ideXlab platform.

  • short term effects of the long acting Insulin Analog detemir and human Insulin on plasma levels of Insulin like growth factor i and its binding proteins in humans
    The Journal of Clinical Endocrinology and Metabolism, 2009
    Co-Authors: Francesca Porcellati, Geremia B Bolli, Paolo Rossetti, Anna Marinelli Andreoli, Paola Candeloro, Paola Lucidi, Patrizia Cioli, E Ghigo, Carmine G Fanelli
    Abstract:

    Objective: The objective of the study was to compare responses of plasma levels of IGF-I and IGF binding proteins (IGFBP-1 and IGFBP-3) induced by human regular Insulin (HI) and the long-acting Insulin Analog detemir (IDet) at doses equivalent with respect to the glucose-lowering effect. Experimental Design: Ten nondiabetic subjects (six males, four females; age, 36 ± 7 yr; body mass index, 22.9 ± 2.6 kg/m2) were studied on four randomized occasions with iv infusion of IDet (2 mU/kg · min for 4 h, followed by 4 mU/kg · min for 1 h) or HI (1 mU/kg · min for 4 h, followed by 2 mU/kg · min for 1 h) in euglycemia [plasma glucose (PG), 90 mg/dl] or during stepped hypoglycemia (PG, 90, 78, 66, 54, and 42 mg/dl). Results: PG was maintained at preselected plateaus, without any significant difference between IDet and HI (P > 0.2). Plasma Insulin concentrations were on average approximately nine times greater with IDet than HI (749 ± 52 vs. 83 ± 19 μU/ml, respectively). Plasma IGF-I concentrations did not change fr...

  • different brain responses to hypoglycemia induced by equipotent doses of the long acting Insulin Analog detemir and human regular Insulin in humans
    Diabetes, 2008
    Co-Authors: Paolo Rossetti, Francesca Porcellati, Geremia B Bolli, Natalia Busciantella Ricci, Paola Candeloro, Patrizia Cioli, Carmine G Fanelli
    Abstract:

    OBJECTIVE— The acylated long-acting Insulin Analog detemir is more lipophilic than human Insulin and likely crosses the blood-to-brain barrier more easily than does human Insulin. The aim of these studies was to assess the brain/hypothalamus responses to euglycemia and hypoglycemia in humans during intravenous infusion of equipotent doses of detemir and human Insulin. RESEARCH DESIGN AND METHODS— Ten normal, nondiabetic subjects (six men, age 36±7 years, and BMI 22.9±2.6 kg/m 2 ) were studied on four occasions at random during intravenous infusion of either detemir or human Insulin in euglycemia (plasma glucose 90 mg/dl) or during stepped hypoglycemia (plasma glucose 90, 78, 66, 54, and 42 mg/dl steps). RESULTS— Plasma counterregulatory hormone response to hypoglycemia did not differ between detemir and human Insulin. The glycemic thresholds for adrenergic symptoms were higher with detemir (51 ± 7.7 mg/dl) versus human Insulin (56 ± 7.8 mg/dl) ( P = 0.029). However, maximal responses were greater with detemir versus human Insulin for adrenergic (3 ± 2.5 vs. 2.4 ± 1.8) and neuroglycopenic (4 ± 3.9 vs. 2.7±2.5) symptoms (score, P P = 0.031), and cognitive function was more deteriorated with detemir versus human Insulin ( P CONCLUSIONS— Compared with human Insulin, responses to hypoglycemia with detemir resulted in higher glycemic thresholds for adrenergic symptoms and greater maximal responses for adrenergic and neuroglycopenic symptoms, with an earlier and greater impairment of cognitive function. Additional studies are needed to establish the effects of detemir on responses to hypoglycemia in subjects with diabetes.

  • pharmacokinetics and pharmacodynamics of the long acting Insulin Analog glargine after 1 week of use compared with its first administration in subjects with type 1 diabetes
    Diabetes Care, 2007
    Co-Authors: Francesca Porcellati, Elisabetta Torlone, S Pampanelli, Geremia B Bolli, Paolo Rossetti, Natalia Busciantella Ricci, Susana Hernandez Campos, Anna Marinelli Andreoli, Carmine G Fanelli
    Abstract:

    Pharmacokinetics and pharmacodynamics of the long-acting Insulin Analog glargine (1) are superior to those of Insulin NPH (2–9). In the clinical setting, this translates into lower risk of nocturnal hypoglycemia (10–13), lower A1C (provided that appropriate requirements of mealtime rapid-acting Insulin are met) (11–13), and the convenience of once (12), compared with multiple, administration of NPH (14). However, no study has examined subjects after several days of its use versus the “first” subcutaneous injection. The present studies were undertaken to establish the pharmacokinetics and pharmacodynamics of Insulin glargine in type 1 diabetes after 1 week of its once-daily use and to compare it with those observed after the first injection. After institutional review board approval, 20 type 1 diabetic subjects (12 male subjects, age 31 ± 2 years, type 1 diabetes duration 11 ± 1 years, BMI 23.3 ± 0.4 kg/m2, fasting plasma C-peptide <0.02 nmol/l, and A1C 7.1 ± 0.2%) using NPH as basal Insulin and human regular Insulin ( n = 7) or lispro Insulin ( n = 13), in combination with NPH at each meal as previously described (14), were studied. During a 2-week run-in period, subjects continued their previous model of Insulin therapy, i.e., human regular Insulin or the rapid-acting Insulin Analog lispro at breakfast, lunch, and dinner and NPH Insulin at bedtime, or even at each meal in those patients ( n = 13) who used lispro (14). Thereafter, subjects were studied with the glucose clamp technique after subcutaneous injection of 0.3 units/kg Insulin glargine as previously described (6). Subjects …

  • pharmacokinetics and pharmacodynamics of subcutaneous injection of long acting human Insulin Analog glargine nph Insulin and ultralente human Insulin and continuous subcutaneous infusion of Insulin lispro
    Diabetes, 2000
    Co-Authors: Marino Lepore, S Pampanelli, Carmine G Fanelli, Francesca Porcellati, L Bartocci, A Di Vincenzo, Cristina Cordoni, P Brunetti, Geremia B Bolli
    Abstract:

    To compare the pharmacokinetics/dynamics of the long-acting Insulin Analog glargine with NPH, ultralente, and continuous subcutaneous (SC) infusion of Insulin lispro (continuous subcutaneous Insulin infusion [CSII]), 20 C-peptide-negative type 1 diabetic patients were studied on four occasions during an isoglycemic 24-h clamp. Patients received SC injection of either 0.3 U/kg glargine or NPH Insulin (random sequence, crossover design). On two subsequent occasions, they received either an SC injection of ultralente (0.3 U/kg) or CSII (0.3 U x kg(-1) x 24 h(-1)) (random sequence, crossover design). After SC Insulin injection or CSII, intravenous (IV) Insulin was tapered, and glucose was infused to clamp plasma glucose at 130 mg/dl for 24 h. Onset of action (defined as reduction of IV Insulin >50%) was earlier with NPH (0.8 +/- 0.2 h), CSII (0.5 +/- 0.1 h), and ultralente (1 +/- 0.2 h) versus glargine (1.5 +/- 0.3 h) (P 150 mg/dl) occurred later with glargine (22 +/- 4 h) than with NPH (14 +/- 3 h) (P < 0.05) but was similar with ultralente (20 +/- 6 h). NPH and ultralente exhibited a peak concentration and action (at 4.5 +/- 0.5 and 10.1 +/- 1 h, respectively) followed by waning, whereas glargine had no peak but had a flat concentration/action profile mimicking CSII. Interindividual variability (calculated as differences in SD of plasma Insulin concentrations and glucose infusion rates in different treatments) was lower with glargine than with NPH and ultralente (P < 0.05) but was similar with glargine and CSII (NS). In conclusion, NPH and ultralente are both peak Insulins. Duration of action of ultralente is greater, but intersubject variability is also greater than that of NPH. Glargine is a peakless Insulin, it lasts nearly 24 h, it has lower intersubject variability than NPH and ultralente, and it closely mimics CSII, the gold standard of basal Insulin replacement.

Qing Xin Hua - One of the best experts on this subject based on the ideXlab platform.

  • design of an active ultrastable single chain Insulin Analog synthesis structure and therapeutic implications
    Journal of Biological Chemistry, 2008
    Co-Authors: Qing Xin Hua, Nelson B Phillips, Satoe H Nakagawa, Wenhua Jia, Kun Huang, Michael A Weiss
    Abstract:

    Single-chain Insulin (SCI) Analogs provide insight into the inter-relation of hormone structure, function, and dynamics. Although compatible with wild-type structure, short connecting segments (<3 residues) prevent induced fit upon receptor binding and so are essentially without biological activity. Substantial but incomplete activity can be regained with increasing linker length. Here, we describe the design, structure, and function of a single-chain Insulin Analog (SCI-57) containing a 6-residue linker (GGGPRR). Native receptor-binding affinity (130 +/- 8% relative to the wild type) is achieved as hindrance by the linker is offset by favorable substitutions in the Insulin moiety. The thermodynamic stability of SCI-57 is markedly increased (DeltaDeltaG(u) = 0.7 +/- 0.1 kcal/mol relative to the corresponding two-chain Analog and 1.9 +/- 0.1 kcal/mol relative to wild-type Insulin). Analysis of inter-residue nuclear Overhauser effects demonstrates that a native-like fold is maintained in solution. Surprisingly, the glycine-rich connecting segment folds against the Insulin moiety: its central Pro contacts Val(A3) at the edge of the hydrophobic core, whereas the final Arg extends the A1-A8 alpha-helix. Comparison between SCI-57 and its parent two-chain Analog reveals striking enhancement of multiple native-like nuclear Overhauser effects within the tethered protein. These contacts are consistent with wild-type crystal structures but are ordinarily attenuated in NMR spectra of two-chain Analogs, presumably due to conformational fluctuations. Linker-specific damping of fluctuations provides evidence for the intrinsic flexibility of an Insulin monomer. In addition to their biophysical interest, ultrastable SCIs may enhance the safety and efficacy of Insulin replacement therapy in the developing world.

  • design of an active ultrastable single chain Insulin Analog synthesis structure and therapeutic implications
    Journal of Biological Chemistry, 2008
    Co-Authors: Qing Xin Hua, Nelson B Phillips, Satoe H Nakagawa, Wenhua Jia, Kun Huang, Michael A Weiss
    Abstract:

    Single-chain Insulin (SCI) Analogs provide insight into the inter-relation of hormone structure, function, and dynamics. Although compatible with wild-type structure, short connecting segments (<3 residues) prevent induced fit upon receptor binding and so are essentially without biological activity. Substantial but incomplete activity can be regained with increasing linker length. Here, we describe the design, structure, and function of a single-chain Insulin Analog (SCI-57) containing a 6-residue linker (GGGPRR). Native receptor-binding affinity (130 ± 8% relative to the wild type) is achieved as hindrance by the linker is offset by favorable substitutions in the Insulin moiety. The thermodynamic stability of SCI-57 is markedly increased (ΔΔGu = 0.7 ± 0.1 kcal/mol relative to the corresponding two-chain Analog and 1.9 ± 0.1 kcal/mol relative to wild-type Insulin). Analysis of inter-residue nuclear Overhauser effects demonstrates that a native-like fold is maintained in solution. Surprisingly, the glycine-rich connecting segment folds against the Insulin moiety: its central Pro contacts ValA3 at the edge of the hydrophobic core, whereas the final Arg extends the A1-A8 α-helix. Comparison between SCI-57 and its parent two-chain Analog reveals striking enhancement of multiple native-like nuclear Overhauser effects within the tethered protein. These contacts are consistent with wild-type crystal structures but are ordinarily attenuated in NMR spectra of two-chain Analogs, presumably due to conformational fluctuations. Linker-specific damping of fluctuations provides evidence for the intrinsic flexibility of an Insulin monomer. In addition to their biophysical interest, ultrastable SCIs may enhance the safety and efficacy of Insulin replacement therapy in the developing world.

  • design of an active ultrastable single chain Insulin Analog synthesis structure and therapeutic implications
    Journal of Biological Chemistry, 2008
    Co-Authors: Qing Xin Hua, Nelson B Phillips, Satoe H Nakagawa, Wenhua Jia, Kun Huang, Michael A Weiss
    Abstract:

    Single-chain Insulin (SCI) Analogs provide insight into the inter-relation of hormone structure, function, and dynamics. Although compatible with wild-type structure, short connecting segments (