1
|
Fischer A, Martirosian P, Machann J, Fränkle B, Schick F. Frequency shifts of free water signals from compact bone: Simulations and measurements using a UTE-FID sequence. Magn Reson Med 2024; 92:257-268. [PMID: 38282291 DOI: 10.1002/mrm.30027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/22/2023] [Accepted: 01/09/2024] [Indexed: 01/30/2024]
Abstract
PURPOSE Free water in cortical bone is either contained in nearly cylindrical structures (mainly Haversian canals oriented parallel to the bone axis) or in more spherically shaped pores (lacunae). Those cavities have been reported to crucially influence bone quality and mechanical stability. Susceptibility differences between bone and water can lead to water frequency shifts dependent on the geometric characteristics. The purpose of this study is to calculate and measure the frequency distribution of the water signal in MRI in dependence of the microscopic bone geometry. METHODS Finite element modeling and analytical approaches were performed to characterize the free water components of bone. The previously introduced UTE-FID technique providing spatially resolved FID-spectra was used to measure the frequency distribution pixel-wise for different orientations of the bone axis. RESULTS The frequency difference between free water in spherical pores and in canals parallel to B0 amounts up to approximately 100 Hz at 3T. Simulated resonance frequencies showed good agreement with the findings in UTE-FID spectra. The intensity ratio of the two signal components (parallel canals and spherical pores) was found to vary between periosteal and endosteal regions. CONCLUSION Spatially resolved UTE-FID examinations allow the determination of the frequency distribution of signals from free water in cortical bone. This frequency distribution indicates the composition of the signal contributions from nearly spherical cavities and cylindrical canals which allows for further characterization of bone structure and status.
Collapse
Affiliation(s)
- Anja Fischer
- Section on Experimental Radiology, University Hospital Tübingen, Tübingen, Germany
- Institute for Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz, Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
| | - Petros Martirosian
- Section on Experimental Radiology, University Hospital Tübingen, Tübingen, Germany
| | - Jürgen Machann
- Section on Experimental Radiology, University Hospital Tübingen, Tübingen, Germany
- Institute for Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz, Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
| | - Bernd Fränkle
- Karlsruhe Institute of Technology, Institute of Mechanical Process Engineering and Mechanics, Karlsruhe, Germany
| | - Fritz Schick
- Section on Experimental Radiology, University Hospital Tübingen, Tübingen, Germany
| |
Collapse
|
2
|
Gerst F, Kemter E, Lorza-Gil E, Kaiser G, Fritz AK, Nano R, Piemonti L, Gauder M, Dahl A, Nadalin S, Königsrainer A, Fend F, Birkenfeld AL, Wagner R, Heni M, Stefan N, Wolf E, Häring HU, Ullrich S. The hepatokine fetuin-A disrupts functional maturation of pancreatic beta cells. Diabetologia 2021; 64:1358-1374. [PMID: 33765181 PMCID: PMC8099843 DOI: 10.1007/s00125-021-05435-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 01/19/2021] [Indexed: 01/02/2023]
Abstract
AIMS/HYPOTHESIS Neonatal beta cells carry out a programme of postnatal functional maturation to achieve full glucose responsiveness. A partial loss of the mature phenotype of adult beta cells may contribute to a reduction of functional beta cell mass and accelerate the onset of type 2 diabetes. We previously found that fetuin-A, a hepatokine increasingly secreted by the fatty liver and a determinant of type 2 diabetes, inhibits glucose-stimulated insulin secretion (GSIS) of human islets. Since fetuin-A is a ubiquitous fetal glycoprotein that declines peripartum, we examined here whether fetuin-A interferes with the functional maturity of beta cells. METHODS The effects of fetuin-A were assessed during in vitro maturation of porcine neonatal islet cell clusters (NICCs) and in adult human islets. Expression alterations were examined via microarray, RNA sequencing and reverse transcription quantitative real-time PCR (qRT-PCR), proteins were analysed by western blotting and immunostaining, and insulin secretion was quantified in static incubations. RESULTS NICC maturation was accompanied by the gain of glucose-responsive insulin secretion (twofold stimulation), backed up by mRNA upregulation of genes governing beta cell identity and function, such as NEUROD1, UCN3, ABCC8 and CASR (Log2 fold change [Log2FC] > 1.6). An active TGFβ receptor (TGFBR)-SMAD2/3 pathway facilitates NICC maturation, since the TGFBR inhibitor SB431542 counteracted the upregulation of aforementioned genes and de-repressed ALDOB, a gene disallowed in mature beta cells. In fetuin-A-treated NICCs, upregulation of beta cell markers and the onset of glucose responsiveness were suppressed. Concomitantly, SMAD2/3 phosphorylation was inhibited. Transcriptome analysis confirmed inhibitory effects of fetuin-A and SB431542 on TGFβ-1- and SMAD2/3-regulated transcription. However, contrary to SB431542 and regardless of cMYC upregulation, fetuin-A inhibited beta cell proliferation (0.27 ± 0.08% vs 1.0 ± 0.1% Ki67-positive cells in control NICCs). This effect was sustained by reduced expression (Log2FC ≤ -2.4) of FOXM1, CENPA, CDK1 or TOP2A. In agreement, the number of insulin-positive cells was lower in fetuin-A-treated NICCs than in control NICCs (14.4 ± 1.2% and 22.3 ± 1.1%, respectively). In adult human islets fetuin-A abolished glucose responsiveness, i.e. 1.7- and 1.1-fold change over 2.8 mmol/l glucose in control- and fetuin-A-cultured islets, respectively. In addition, fetuin-A reduced SMAD2/3 phosphorylation and suppressed expression of proliferative genes. Of note, in non-diabetic humans, plasma fetuin-A was negatively correlated (p = 0.013) with islet beta cell area. CONCLUSIONS/INTERPRETATION Our results suggest that the perinatal decline of fetuin-A relieves TGFBR signalling in islets, a process that facilitates functional maturation of neonatal beta cells. Functional maturity remains revocable in later life, and the occurrence of a metabolically unhealthy milieu, such as liver steatosis and elevated plasma fetuin-A, can impair both function and adaptive proliferation of beta cells. DATA AVAILABILITY The RNAseq datasets and computer code produced in this study are available in the Gene Expression Omnibus (GEO): GSE144950; https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE144950.
Collapse
Affiliation(s)
- Felicia Gerst
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany.
- Internal Medicine IV, Endocrinology, Diabetology and Nephrology, University Hospital Tuebingen, Tuebingen, Germany.
- German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany.
| | - Elisabeth Kemter
- Department of Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, Ludwig Maximilians University, Munich, Germany
| | - Estela Lorza-Gil
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany
- Internal Medicine IV, Endocrinology, Diabetology and Nephrology, University Hospital Tuebingen, Tuebingen, Germany
- German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany
| | - Gabriele Kaiser
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany
- Internal Medicine IV, Endocrinology, Diabetology and Nephrology, University Hospital Tuebingen, Tuebingen, Germany
- German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany
| | - Ann-Kathrin Fritz
- Internal Medicine IV, Endocrinology, Diabetology and Nephrology, University Hospital Tuebingen, Tuebingen, Germany
| | - Rita Nano
- Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Lorenzo Piemonti
- Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Marie Gauder
- Quantitative Biology Center (QBiC) Eberhard Karls University of Tuebingen, Tuebingen, Germany
| | - Andreas Dahl
- Biotechnology Center TU Dresden, Dresden, Germany
| | - Silvio Nadalin
- Department of General, Visceral and Transplant Surgery, University Hospital Tuebingen, Tuebingen, Germany
| | - Alfred Königsrainer
- Department of General, Visceral and Transplant Surgery, University Hospital Tuebingen, Tuebingen, Germany
| | - Falko Fend
- Department of General Pathology and Pathological Anatomy, University Hospital Tuebingen, Tuebingen, Germany
| | - Andreas L Birkenfeld
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany
- Internal Medicine IV, Endocrinology, Diabetology and Nephrology, University Hospital Tuebingen, Tuebingen, Germany
- German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany
| | - Robert Wagner
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany
- Internal Medicine IV, Endocrinology, Diabetology and Nephrology, University Hospital Tuebingen, Tuebingen, Germany
- German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany
| | - Martin Heni
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany
- Internal Medicine IV, Endocrinology, Diabetology and Nephrology, University Hospital Tuebingen, Tuebingen, Germany
- German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany
| | - Norbert Stefan
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany
- Internal Medicine IV, Endocrinology, Diabetology and Nephrology, University Hospital Tuebingen, Tuebingen, Germany
- German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany
| | - Eckhard Wolf
- Department of Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, Ludwig Maximilians University, Munich, Germany
| | - Hans-Ulrich Häring
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany
- Internal Medicine IV, Endocrinology, Diabetology and Nephrology, University Hospital Tuebingen, Tuebingen, Germany
- German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany
| | - Susanne Ullrich
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany
- Internal Medicine IV, Endocrinology, Diabetology and Nephrology, University Hospital Tuebingen, Tuebingen, Germany
- German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany
| |
Collapse
|
3
|
Abstract
The aim of this work was to review studies in which genetic variants were assessed with respect to metabolic response to treatment with novel glucose-lowering drugs: dipeptidyl peptidase-4 inhibitors (DPP-4i), glucagon-like peptide-1 receptor agonists (GLP-1 RA) and sodium-glucose cotransporter 2 inhibitors (SGLT2i). In total, 22 studies were retrieved from the literature (MEDLINE). Variants of the GLP-1 receptor gene (GLP1R) were associated with a smaller reduction in HbA1c in response to DPP-4i. Variants of a number of other genes (KCNQ1, KCNJ11, CTRB1/2, PRKD1, CDKAL1, IL6 promoter region, TCF7L2, DPP4, PNPLA3) have also been related to DPP-4i response, although replication studies are lacking. The GLP1R gene was also reported to play a role in the response to GLP-1 RA, with larger weight reductions being reported in carriers of GLP1R variant alleles. There were variants of a few other genes (CNR1, TCF7L2, SORCS1) described to be related to GLP-1 RA. For SGLT2i, studies have focused on genes affecting renal glucose reabsorption (e.g. SLC5A2) but no relationship between SLC5A2 variants and response to empagliflozin has been found. The relevance of the included studies is limited due to small genetic effects, low sample sizes, limited statistical power, inadequate statistics (lack of gene-drug interactions), inadequate accounting for confounders and effects modifiers, and a lack of replication studies. Most studies have been based on candidate genes. Genome-wide association studies, in that respect, may be a more promising approach to providing novel insights. However, the identification of distinct subgroups of type 2 diabetes might also be necessary before pharmacogenetic studies can be successfully used for a stratified prescription of novel glucose-lowering drugs.
Collapse
Affiliation(s)
- Wolfgang Rathmann
- Institute for Biometrics and Epidemiology, German Diabetes Center, Leibniz Institute for Diabetes Research at Heinrich Heine University, Düsseldorf, Germany.
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany.
| | - Brenda Bongaerts
- Institute for Biometrics and Epidemiology, German Diabetes Center, Leibniz Institute for Diabetes Research at Heinrich Heine University, Düsseldorf, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| |
Collapse
|
4
|
Assfalg R, Knoop J, Hoffman KL, Pfirrmann M, Zapardiel-Gonzalo JM, Hofelich A, Eugster A, Weigelt M, Matzke C, Reinhardt J, Fuchs Y, Bunk M, Weiss A, Hippich M, Halfter K, Hauck SM, Hasford J, Petrosino JF, Achenbach P, Bonifacio E, Ziegler AG. Oral insulin immunotherapy in children at risk for type 1 diabetes in a randomised controlled trial. Diabetologia 2021; 64:1079-1092. [PMID: 33515070 PMCID: PMC8012335 DOI: 10.1007/s00125-020-05376-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/12/2020] [Indexed: 12/13/2022]
Abstract
AIMS/HYPOTHESIS Oral administration of antigen can induce immunological tolerance. Insulin is a key autoantigen in childhood type 1 diabetes. Here, oral insulin was given as antigen-specific immunotherapy before the onset of autoimmunity in children from age 6 months to assess its safety and immune response actions on immunity and the gut microbiome. METHODS A phase I/II randomised controlled trial was performed in a single clinical study centre in Germany. Participants were 44 islet autoantibody-negative children aged 6 months to 2.99 years who had a first-degree relative with type 1 diabetes and a susceptible HLA DR4-DQ8-containing genotype. Children were randomised 1:1 to daily oral insulin (7.5 mg with dose escalation to 67.5 mg) or placebo for 12 months using a web-based computer system. The primary outcome was immune efficacy pre-specified as induction of antibody or T cell responses to insulin and measured in a central treatment-blinded laboratory. RESULTS Randomisation was performed in 44 children. One child in the placebo group was withdrawn after the first study visit and data from 22 insulin-treated and 21 placebo-treated children were analysed. Oral insulin was well tolerated with no changes in metabolic variables. Immune responses to insulin were observed in children who received both insulin (54.5%) and placebo (66.7%), and the trial did not demonstrate an effect on its primary outcome (p = 0.54). In exploratory analyses, there was preliminary evidence that the immune response and gut microbiome were modified by the INS genotype Among children with the type 1 diabetes-susceptible INS genotype (n = 22), antibody responses to insulin were more frequent in insulin-treated (72.7%) as compared with placebo-treated children (18.2%; p = 0.03). T cell responses to insulin were modified by treatment-independent inflammatory episodes. CONCLUSIONS/INTERPRETATION The study demonstrated that oral insulin immunotherapy in young genetically at-risk children was safe, but was not associated with an immune response as predefined in the trial primary outcome. Exploratory analyses suggested that antibody responses to oral insulin may occur in children with a susceptible INS genotype, and that inflammatory episodes may promote the activation of insulin-responsive T cells. TRIAL REGISTRATION Clinicaltrials.gov NCT02547519 FUNDING: The main funding source was the German Center for Diabetes Research (DZD e.V.).
Collapse
Affiliation(s)
- Robin Assfalg
- Institute of Diabetes Research, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich-Neuherberg, Germany
- Forschergruppe Diabetes, Technical University Munich, at Klinikum rechts der Isar, Munich, Germany
- German Center for Diabetes Research (DZD), Munich, Germany
| | - Jan Knoop
- Institute of Diabetes Research, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich-Neuherberg, Germany
| | - Kristi L Hoffman
- Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Markus Pfirrmann
- Institute for Medical Information Processing, Biometry, and Epidemiology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Jose Maria Zapardiel-Gonzalo
- Institute of Diabetes Research, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich-Neuherberg, Germany
| | - Anna Hofelich
- Forschergruppe Diabetes, Technical University Munich, at Klinikum rechts der Isar, Munich, Germany
| | - Anne Eugster
- Technische Universität Dresden, Center for Regenerative Therapies Dresden, Dresden, Germany
- Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital Carl Gustav Carus and Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Marc Weigelt
- Technische Universität Dresden, Center for Regenerative Therapies Dresden, Dresden, Germany
| | - Claudia Matzke
- Institute of Diabetes Research, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich-Neuherberg, Germany
| | - Julia Reinhardt
- Technische Universität Dresden, Center for Regenerative Therapies Dresden, Dresden, Germany
| | - Yannick Fuchs
- Technische Universität Dresden, Center for Regenerative Therapies Dresden, Dresden, Germany
| | - Melanie Bunk
- Institute of Diabetes Research, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich-Neuherberg, Germany
| | - Andreas Weiss
- Institute of Diabetes Research, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich-Neuherberg, Germany
| | - Markus Hippich
- Institute of Diabetes Research, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich-Neuherberg, Germany
| | - Kathrin Halfter
- Institute for Medical Information Processing, Biometry, and Epidemiology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Stefanie M Hauck
- Research Unit Protein Science, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich-Neuherberg, Germany
| | - Jörg Hasford
- Institute for Medical Information Processing, Biometry, and Epidemiology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Joseph F Petrosino
- Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Peter Achenbach
- Institute of Diabetes Research, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich-Neuherberg, Germany
- Forschergruppe Diabetes, Technical University Munich, at Klinikum rechts der Isar, Munich, Germany
- German Center for Diabetes Research (DZD), Munich, Germany
| | - Ezio Bonifacio
- German Center for Diabetes Research (DZD), Munich, Germany
- Technische Universität Dresden, Center for Regenerative Therapies Dresden, Dresden, Germany
- Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital Carl Gustav Carus and Faculty of Medicine, TU Dresden, Dresden, Germany
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, Munich-Neuherberg, Germany
| | - Anette-Gabriele Ziegler
- Institute of Diabetes Research, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich-Neuherberg, Germany.
- Forschergruppe Diabetes, Technical University Munich, at Klinikum rechts der Isar, Munich, Germany.
- German Center for Diabetes Research (DZD), Munich, Germany.
| |
Collapse
|