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Galimov A, Hartung A, Trepp R, Mader A, Flück M, Linke A, Blüher M, Christ E, Krützfeldt J. Growth hormone replacement therapy regulates microRNA-29a and targets involved in insulin resistance. J Mol Med (Berl) 2015. [PMID: 26199111 PMCID: PMC4661224 DOI: 10.1007/s00109-015-1322-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Abstract Replacement of growth hormone (GH) in patients suffering from GH deficiency (GHD) offers clinical benefits on body composition, exercise capacity, and skeletal integrity. However, GH replacement therapy (GHRT) is also associated with insulin resistance, but the mechanisms are incompletely understood. We demonstrate that in GH-deficient mice (growth hormone-releasing hormone receptor (Ghrhr)lit/lit), insulin resistance after GHRT involves the upregulation of the extracellular matrix (ECM) and the downregulation of microRNA miR-29a in skeletal muscle. Based on RNA deep sequencing of skeletal muscle from GH-treated Ghrhrlit/lit mice, we identified several upregulated genes as predicted miR-29a targets that are negative regulators of insulin signaling or profibrotic/proinflammatory components of the ECM. Using gain- and loss-of-function studies, five of these genes were confirmed as endogenous targets of miR-29a in human myotubes (PTEN, COL3A1, FSTL1, SERPINH1, SPARC). In addition, in human myotubes, IGF1, but not GH, downregulated miR-29a expression and upregulated COL3A1. These results were confirmed in a group of GH-deficient patients after 4 months of GHRT. Serum IGF1 increased, skeletal muscle miR-29a decreased, and miR-29a targets were upregulated in patients with a reduced insulin response (homeostatic model assessment of insulin resistance (HOMA-IR)) after GHRT. We conclude that miR-29a could contribute to the metabolic response of muscle tissue to GHRT by regulating ECM components and PTEN. miR-29a and its targets might be valuable biomarkers for muscle metabolism following GH replacement. Key messages GHRT most significantly affects the ECM cluster in skeletal muscle from mice. GHRT downregulates miR-29a and upregulates miR-29a targets in skeletal muscle from mice. PTEN, COL3A1, FSTL1, SERPINH1, and SPARC are endogenous miR-29a targets in human myotubes. IGF1 decreases miR-29a levels in human myotubes. miR-29a and its targets are regulated during GHRT in skeletal muscle from humans.
Electronic supplementary material The online version of this article (doi:10.1007/s00109-015-1322-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Artur Galimov
- Division of Endocrinology, Diabetes, and Clinical Nutrition, University of Zurich and University Hospital, Rämistrasse 100, 8091, Zurich, Switzerland.,Competence Center Personalized Medicine, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Angelika Hartung
- Division of Endocrinology, Diabetes, and Clinical Nutrition, University of Zurich and University Hospital, Rämistrasse 100, 8091, Zurich, Switzerland
| | - Roman Trepp
- Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Bern Inselspital, Bern, Switzerland
| | - Alexander Mader
- Division of Trauma Surgery, University Hospital, Zurich, Switzerland
| | - Martin Flück
- Department of Orthopedics, University Hospital Balgrist, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Axel Linke
- Heart Center Leipzig, University of Leipzig, Leipzig, Germany
| | - Matthias Blüher
- Department of Medicine, University of Leipzig, Leipzig, Germany
| | - Emanuel Christ
- Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Bern Inselspital, Bern, Switzerland
| | - Jan Krützfeldt
- Division of Endocrinology, Diabetes, and Clinical Nutrition, University of Zurich and University Hospital, Rämistrasse 100, 8091, Zurich, Switzerland. .,Competence Center Personalized Medicine, ETH Zurich and University of Zurich, Zurich, Switzerland. .,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
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Haberl Meglic S, Marolt T, Miklavcic D. Protein Extraction by Means of Electroporation from E. coli with Preserved Viability. J Membr Biol 2015. [PMID: 26201287 DOI: 10.1007/s00232-015-9824-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Extracting proteins by means of electroporation from different microorganisms is gaining on its importance, as electroporation is a quick, chemical-free, and cost-effective method. Since complete cell destruction (to obtain proteins) necessitates additional work, and cost of purifying the end-product is high, pulses have to be adjusted in order to prevent total disintegration. Namely, total disintegration of the cell releases bacterial membrane contaminants in the final sample. Therefore, our goal was to study different electric pulse parameters in order to extract as much proteins as possible from E. coli bacteria, while preserving bacterial viability. Our results show that by increasing electric field strength the concentration of extracted proteins increases and viability reduces. The correlation is reasonable, since high electric field destroys bacterial envelope, releasing all intracellular components into surrounding media. The strong correlation was also found with pulse duration. However, at longer pulses we obtained more proteins, while bacterial viability was not as much affected. Pulse number and/or pulse repetition frequency at our conditions have no or little effect on concentration of extracted proteins and/or bacterial viability. We can conclude that the most promising pulse protocol for protein extraction by means of electroporation based on our experience would be longer pulses with lower pulse amplitude assuring high protein yield and low effect on bacterial viability.
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Affiliation(s)
- Sasa Haberl Meglic
- Laboratory of Biocybernetics, Faculty of Electrical Engineering, University of Ljubljana, Trzaska 25, 1000, Ljubljana, Slovenia
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53
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Scranton RA, Baskin DS. Impaired Pituitary Axes Following Traumatic Brain Injury. J Clin Med 2015; 4:1463-79. [PMID: 26239686 PMCID: PMC4519800 DOI: 10.3390/jcm4071463] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 06/29/2015] [Accepted: 07/06/2015] [Indexed: 12/24/2022] Open
Abstract
Pituitary dysfunction following traumatic brain injury (TBI) is significant and rarely considered by clinicians. This topic has received much more attention in the last decade. The incidence of post TBI anterior pituitary dysfunction is around 30% acutely, and declines to around 20% by one year. Growth hormone and gonadotrophic hormones are the most common deficiencies seen after traumatic brain injury, but also the most likely to spontaneously recover. The majority of deficiencies present within the first year, but extreme delayed presentation has been reported. Information on posterior pituitary dysfunction is less reliable ranging from 3%-40% incidence but prospective data suggests a rate around 5%. The mechanism, risk factors, natural history, and long-term effect of treatment are poorly defined in the literature and limited by a lack of standardization. Post TBI pituitary dysfunction is an entity to recognize with significant clinical relevance. Secondary hypoadrenalism, hypothyroidism and central diabetes insipidus should be treated acutely while deficiencies in growth and gonadotrophic hormones should be initially observed.
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Affiliation(s)
- Robert A Scranton
- Department of Neurosurgery and the Kenneth R. Peak Brain and Pituitary Tumor Treatment Center, Houston Methodist Neurological Institute, 6560 Fannin St. Suite 944, Houston, TX 77030, USA.
| | - David S Baskin
- Department of Neurosurgery and the Kenneth R. Peak Brain and Pituitary Tumor Treatment Center, Houston Methodist Neurological Institute, 6560 Fannin St. Suite 944, Houston, TX 77030, USA.
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54
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Lubrano C, Tenuta M, Costantini D, Specchia P, Barbaro G, Basciani S, Mariani S, Pontecorvi A, Lenzi A, Gnessi L. Severe growth hormone deficiency and empty sella in obesity: a cross-sectional study. Endocrine 2015; 49:503-11. [PMID: 25614038 DOI: 10.1007/s12020-015-0530-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 01/10/2015] [Indexed: 12/29/2022]
Abstract
Obesity is associated with blunted growth hormone (GH) secretion. In some individuals, hypothalamic-pituitary (HP) structural lesions may contribute to GH deficiency (GHD). We explored pituitary morphology in obese patients with suspected GHD and its association with cardiovascular risk factors, body composition, and cardiac morphology. One hundred and eighty-four adults obese patients with symptoms and signs of GHD (147 females and 37 males; mean age 46.31 ± 12.11 years), out of 906 consecutive white obese outpatients, were evaluated. The main measures were anthropometric data, blood pressure, lipid profile, glycemic parameters, pituitary hormones, and insulin-like growth factor-1 values, echocardiography, magnetic resonance imaging (MRI) of the HP region, body composition, and growth hormone-releasing hormone plus arginine test. Seventy patients had GHD (GH peak values <4.2 μg/mL). GHD patients showed significantly higher body mass index and fat mass, lower lumbar bone mineral density, increased left ventricular mass index, and epicardial fat thickness. The MRI of the HP region showed empty sella (ES) in 69 and normal pituitary in one of the 70 GHD patients; the 114 patients with normal GH response had ES (n = 62, 54 %), normal pituitary (n = 37, 32 %), microadenomas (n = 10, 8 %), and other pituitary abnormalities (n = 5, 4 %). ES was a significant independent predictor of GH secretory capacity as determined by multiple regression analysis. The close relationship between ES and GH secretory capacity points out to the possibility of the organic nature of GHD in a portion of obese individuals and opens a new scenario with regard to the potential of GH treatment on metabolic consequences of obesity.
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Affiliation(s)
- Carla Lubrano
- Section of Medical Pathophysiology, Food Science and Endocrinology, Department of Experimental Medicine, University of Rome "La Sapienza", Policlinico Umberto I, 00161, Rome, Italy
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Kristensen M, de Groot AM, Berthelsen J, Franzyk H, Sijts A, Nielsen HM. Conjugation of cell-penetrating peptides to parathyroid hormone affects its structure, potency, and transepithelial permeation. Bioconjug Chem 2015; 26:477-88. [PMID: 25611217 DOI: 10.1021/bc5005763] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Delivery of therapeutic peptides and proteins by the use of cell-penetrating peptides (CPPs) as carriers has been suggested as a feasible strategy. The aim of the present study was to investigate the effect of conjugating a series of well-known CPPs to the biologically active part of parathyroid hormone, i.e., PTH(1-34), and to evaluate the effect with regard to secondary structure, potency in Saos-2 cells, immunogenicity, safety, as well as the transepithelial permeation across monolayers by using the Caco-2 cell culture model. Further, co-administration of CPP and PTH(1-34) as an alternative to covalent conjugation was compared with regard to the transepithelial permeation. CPP-conjugated PTH(1-34) fusion peptides were successfully expressed in Escherichia coli and purified from inclusion bodies. No clear correlation between the degree of secondary structure of the CPP-conjugated PTH(1-34) fusion peptides and their potency was found, albeit a general decrease in permeation was observed for both N- and C-terminally CPP-conjugated PTH(1-34) as compared to native PTH(1-34). However, attachment of CPP to the N-terminus significantly increased permeation across Caco-2 cell monolayers as compared to the corresponding C-terminally CPP-conjugated PTH(1-34). In addition, the nonaarginine sequence proved to be the only CPP capable of increasing permeation when conjugated to PTH(1-34) as compared to co-administration of CPP and PTH(1-34). This enhancement effect was, however, associated with an unacceptably low level of cell viability. In conclusion, covalent conjugation of CPPs to PTH(1-34) influenced the secondary structure, potency, and transepithelial permeation efficiency of the resulting conjugate, and hence this approach appears not to be favorable as compared to co-administration when optimizing CPP-mediated permeation of PTH(1-34) across an intestinal epithelium.
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Affiliation(s)
- Mie Kristensen
- †Section for Biologics, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Anne Marit de Groot
- §Division of Immunology, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University. Yalelaan 1, 3584 CL Utrecht, The Netherlands
| | - Jens Berthelsen
- ‡Department of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen, Denmark
| | - Henrik Franzyk
- ∥Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Alice Sijts
- §Division of Immunology, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University. Yalelaan 1, 3584 CL Utrecht, The Netherlands
| | - Hanne Mørck Nielsen
- †Section for Biologics, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
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Shimatsu A, Iwamoto N, Tanaka T, Teramoto A, Taketsuna M, Ihara K, Funai J, Irie M, Chihara K. Possible predictors for QOL improvement following GH replacement therapy in adult GHD. Endocr J 2015; 62:749-56. [PMID: 26073867 DOI: 10.1507/endocrj.ej14-0616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
In addition to impaired physical activity, adult GH deficiency (GHD) can decrease quality of life (QOL). Hence, assessment of QOL is important to evaluate the efficacy of GH replacement therapy. This study aimed to identify factors that may be predictive of long-term improvement in QOL among clinical/laboratory variables during GH replacement therapy. The analysis included 83 Japanese adults with GHD who participated in the Hypopituitary Control and Complications Study (HypoCCS). Correlations between the change from baseline in clinical/laboratory variables at 6 months and the change from baseline in Quality of life (Short-Form 36 [SF-36] component scores) at 12 months were examined. Unexpectedly, all component scores were negatively correlated with the change in fasting plasma glucose concentration (FPG) (physical component summary [PCS], r = -0.456; mental component summary [MCS], r = -0.523; role/social component summary [RCS], r = -0.433). The change in MCS was positively correlated with the change in insulin-like growth factor-1 standard deviation score (IGF-1 SDS) (r = 0.417). The change in PCS was positively correlated with the change in body fat (r = 0.551). The change in RCS was positively correlated with the change in waist circumference (r = 0.528). Short-term changes in several clinical/laboratory variables, most notably FPG and IGF-1 SDS, were correlated with long-term changes in QOL. The clinical importance of these correlations for predicting GH replacement treatment efficacy warrants further investigation.
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Affiliation(s)
- Akira Shimatsu
- Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Kyoto, Japan
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57
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Bielohuby M, Zarkesh-Esfahani SH, Manolopoulou J, Wirthgen E, Walpurgis K, Toghiany Khorasgani M, Aghili ZS, Wilkinson IR, Hoeflich A, Thevis M, Ross RJ, Bidlingmaier M. Validation of serum IGF-I as a biomarker to monitor the bioactivity of exogenous growth hormone agonists and antagonists in rabbits. Dis Model Mech 2014; 7:1263-73. [PMID: 25239917 PMCID: PMC4213730 DOI: 10.1242/dmm.016519] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The development of new growth hormone (GH) agonists and growth hormone antagonists (GHAs) requires animal models for pre-clinical testing. Ideally, the effects of treatment are monitored using the same pharmacodynamic marker that is later used in clinical practice. However, intact rodents are of limited value for this purpose because serum IGF-I, the most sensitive pharmacodynamic marker for the action of GH in humans, shows no response to treatment with recombinant human GH and there is little evidence for the effects of GHAs, except when administered at very high doses or when overexpressed. As an alternative, more suitable model, we explored pharmacodynamic markers of GH action in intact rabbits. We performed the first validation of an IGF-I assay for the analysis of rabbit serum and tested precision, sensitivity, linearity and recovery using an automated human IGF-I assay (IDS-iSYS). Furthermore, IGF-I was measured in rabbits of different strains, age groups and sexes, and we monitored IGF-I response to treatment with recombinant human GH or the GHA Pegvisomant. For a subset of samples, we used LC-MS/MS to measure IGF-I, and quantitative western ligand blot to analyze IGF-binding proteins (IGFBPs). Although recovery of recombinant rabbit IGF-I was only 50% in the human IGF-I assay, our results show that the sensitivity, precision (1.7–3.3% coefficient of variation) and linearity (90.4–105.6%) were excellent in rabbit samples. As expected, sex, age and genetic background were major determinants of IGF-I concentration in rabbits. IGF-I and IGFBP-2 levels increased after single and multiple injections of recombinant human GH (IGF-I: 286±22 versus 434±26 ng/ml; P<0.01) and were highly correlated (P<0.0001). Treatment with the GHA lowered IGF-I levels from the fourth injection onwards (P<0.01). In summary, we demonstrated that the IDS-iSYS IGF-I immunoassay can be used in rabbits. Similar to rodents, rabbits display variations in IGF-I depending on sex, age and genetic background. Unlike in rodents, the IGF-I response to treatment with recombinant human GH or a GHA closely mimics the pharmacodynamics seen in humans, suggesting that rabbits are a suitable new model to test human GH agonists and antagonists.
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Affiliation(s)
- Maximilian Bielohuby
- Endocrine Research Unit, Medizinische Klinik und Poliklinik IV, Ludwig-Maximilians University, 80336 Munich, Germany
| | - Sayyed Hamid Zarkesh-Esfahani
- Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan 81746-73695, Iran. Department of Immunology, Medical School, Isfahan University of Medical Sciences, Isfahan 81746-73461, Iran. The Department of Human Metabolism, The University of Sheffield, Sheffield S10 2JF, UK
| | | | - Elisa Wirthgen
- Ligandis GbR, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - Katja Walpurgis
- German Sport University Cologne, Institute of Biochemisty/Center for Preventive Doping Research, 50933 Cologne, Germany
| | | | - Zahra Sadat Aghili
- Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan 81746-73695, Iran
| | - Ian Robert Wilkinson
- The Department of Human Metabolism, The University of Sheffield, Sheffield S10 2JF, UK
| | - Andreas Hoeflich
- Leibniz Institute for Farm Animal Biology (FBN), Institute of Genome Biology, 18196 Dummerstorf, Germany
| | - Mario Thevis
- German Sport University Cologne, Institute of Biochemisty/Center for Preventive Doping Research, 50933 Cologne, Germany
| | - Richard J Ross
- The Department of Human Metabolism, The University of Sheffield, Sheffield S10 2JF, UK
| | - Martin Bidlingmaier
- Endocrine Research Unit, Medizinische Klinik und Poliklinik IV, Ludwig-Maximilians University, 80336 Munich, Germany.
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Reed ML, Merriam GR, Kargi AY. Adult growth hormone deficiency - benefits, side effects, and risks of growth hormone replacement. Front Endocrinol (Lausanne) 2013; 4:64. [PMID: 23761782 PMCID: PMC3671347 DOI: 10.3389/fendo.2013.00064] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 05/18/2013] [Indexed: 11/26/2022] Open
Abstract
Deficiency of growth hormone (GH) in adults results in a syndrome characterized by decreased muscle mass and exercise capacity, increased visceral fat, impaired quality of life, unfavorable alterations in lipid profile and markers of cardiovascular risk, decrease in bone mass and integrity, and increased mortality. When dosed appropriately, GH replacement therapy (GHRT) is well tolerated, with a low incidence of side effects, and improves most of the alterations observed in GH deficiency (GHD); beneficial effects on mortality, cardiovascular events, and fracture rates, however, remain to be conclusively demonstrated. The potential of GH to act as a mitogen has resulted in concern over the possibility of increased de novo tumors or recurrence of pre-existing malignancies in individuals treated with GH. Though studies of adults who received GHRT in childhood have produced conflicting reports in this regard, long-term surveillance of adult GHRT has not demonstrated increased cancer risk or mortality.
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Affiliation(s)
- Mary L. Reed
- Geriatrics and Extended Care, VA Puget Sound Health Care System, Madigan Health Care System, Tacoma, WA, USA
| | - George R. Merriam
- Division of Metabolism, Endocrinology, and Nutrition, VA Puget Sound Health Care System, University of Washington School of Medicine, Tacoma, WA, USA
| | - Atil Y. Kargi
- Division of Endocrinology, Diabetes, and Metabolism, University of Miami Miller School of Medicine, Miami, FL, USA
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