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Schweighofer N, Strasser M, Obermayer A, Trummer O, Sourij H, Sourij C, Obermayer-Pietsch B. Identification of Novel Intronic SNPs in Transporter Genes Associated with Metformin Side Effects. Genes (Basel) 2023; 14:1609. [PMID: 37628660 PMCID: PMC10454417 DOI: 10.3390/genes14081609] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/08/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
Metformin is a widely used and effective medication in type 2 diabetes (T2DM) as well as in polycystic ovary syndrome (PCOS). Single nucleotide polymorphisms (SNPs) contribute to the occurrence of metformin side effects. The aim of the present study was to identify intronic genetic variants modifying the occurrence of metformin side effects and to replicate them in individuals with T2DM and in women with PCOS. We performed Next Generation Sequencing (Illumina Next Seq) of 115 SNPs in a discovery cohort of 120 metformin users and conducted a systematic literature review. Selected SNPs were analysed in two independent cohorts of individuals with either T2DM or PCOS, using 5'-3'exonucleaseassay. A total of 14 SNPs in the organic cation transporters (OCTs) showed associations with side effects in an unadjusted binary logistic regression model, with eight SNPs remaining significantly associated after appropriate adjustment in the discovery cohort. Five SNPs were confirmed in a combined analysis of both replication cohorts but showed different association patterns in subgroup analyses. In an unweighted polygenic risk score (PRS), the risk for metformin side effects increased with the number of risk alleles. Intronic SNPs in the OCT cluster contribute to the development of metformin side effects in individuals with T2DM and in women with PCOS and are therefore of interest for personalized therapy options.
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Affiliation(s)
- Natascha Schweighofer
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria; (N.S.); (M.S.); (A.O.); (H.S.); barbar (B.O.-P.)
- Center for Biomarker Research in Medicine, CBmed, 8010 Graz, Austria
| | - Moritz Strasser
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria; (N.S.); (M.S.); (A.O.); (H.S.); barbar (B.O.-P.)
- Department of Health Studies, Institute of Biomedical, FH Joanneum University of Applied Sciences, 8020 Graz, Austria
| | - Anna Obermayer
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria; (N.S.); (M.S.); (A.O.); (H.S.); barbar (B.O.-P.)
- Interdisciplinary Metabolic Medicine Trials Unit, Medical University of Graz, 8036 Graz, Austria
| | - Olivia Trummer
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria; (N.S.); (M.S.); (A.O.); (H.S.); barbar (B.O.-P.)
| | - Harald Sourij
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria; (N.S.); (M.S.); (A.O.); (H.S.); barbar (B.O.-P.)
- Interdisciplinary Metabolic Medicine Trials Unit, Medical University of Graz, 8036 Graz, Austria
| | - Caren Sourij
- Division of Cardiology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria;
| | - Barbara Obermayer-Pietsch
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria; (N.S.); (M.S.); (A.O.); (H.S.); barbar (B.O.-P.)
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Schweighofer N, Colantonio C, Haudum CW, Hutz B, Schmidt A, Zirlik A, Pieber TR, Verheyen N, Obermayer-Pietsch B. Dp-ucMGP – a modulator in disease with an inflammatory component? Bone Rep 2022. [DOI: 10.1016/j.bonr.2022.101312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Haudum CW, Kolesnik E, Colantonio C, Mursic I, Url-Michitsch M, Tomaschitz A, Glantschnig T, Hutz B, Lind A, Schweighofer N, Reiter C, Ablasser K, Wallner M, Tripolt NJ, Pieske-Kraigher E, Madl T, Springer A, Seidel G, Wedrich A, Zirlik A, Krahn T, Stauber R, Pieske B, Pieber TR, Verheyen N, Obermayer-Pietsch B, Schmidt A. Cohort profile: 'Biomarkers of Personalised Medicine' (BioPersMed): a single-centre prospective observational cohort study in Graz/Austria to evaluate novel biomarkers in cardiovascular and metabolic diseases. BMJ Open 2022; 12:e058890. [PMID: 35393327 PMCID: PMC8991072 DOI: 10.1136/bmjopen-2021-058890] [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] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
PURPOSE Accumulating evidence points towards a close relationship between cardiovascular, endocrine and metabolic diseases. The BioPersMed Study (Biomarkers of Personalised Medicine) is a single-centre prospective observational cohort study with repetitive examination of participants in 2-year intervals. The aim is to evaluate the predictive impact of various traditional and novel biomarkers of cardiovascular, endocrine and metabolic pathways in asymptomatic individuals at risk for cardiovascular and/or metabolic disease. PARTICIPANTS Between 2010 and 2016, we recruited 1022 regional individuals into the study. Subjects aged 45 years or older presenting with at least one traditional cardiovascular risk factor or manifest type 2 diabetes mellitus (T2DM) were enrolled. The mean age of the participants was 57±8 years, 55% were female, 18% had T2DM, 33% suffered from arterial hypertension, 15% were smokers, 42% had hyperlipidaemia, and only 26% were at low cardiovascular risk according to the Framingham 'Systematic COronary Risk Evaluation'. FINDINGS TO DATE Study procedures during screening and follow-up visits included a physical examination and comprehensive cardiovascular, endocrine, metabolic, ocular and laboratory workup with biobanking of blood and urine samples. The variety of assessed biomarkers allows a full phenotyping of individuals at cardiovascular and metabolic risk. Preliminary data from the cohort and relevant biomarker analyses were already used as control population for genomic studies in local and international research cooperation. FUTURE PLANS Participants will undergo comprehensive cardiovascular, endocrine and metabolic examinations for the next decades and clinical outcomes will be adjudicated prospectively.
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Affiliation(s)
- Christoph Walter Haudum
- Center for Biomarker Research in Medicine, Graz, Austria
- Department of Internal Medicine, Medical University, Graz, Austria
| | - Ewald Kolesnik
- Department of Internal Medicine, Medical University and University Heart Center, Graz, Austria
| | - Caterina Colantonio
- Department of Internal Medicine, Medical University and University Heart Center, Graz, Austria
| | - Ines Mursic
- Department of Internal Medicine, Medical University, Graz, Austria
| | - Marion Url-Michitsch
- Department of Internal Medicine, Medical University and University Heart Center, Graz, Austria
| | - Andreas Tomaschitz
- Department of Internal Medicine, Medical University and University Heart Center, Graz, Austria
| | - Theresa Glantschnig
- Department of Internal Medicine, Medical University and University Heart Center, Graz, Austria
| | - Barbara Hutz
- Department of Internal Medicine, Medical University, Graz, Austria
| | - Alice Lind
- Department of Internal Medicine, Medical University, Graz, Austria
| | | | - Clemens Reiter
- Department of Internal Medicine, Medical University and University Heart Center, Graz, Austria
- Department of Radiology, Medizinische Universitat, Graz, Austria
| | - Klemens Ablasser
- Department of Internal Medicine, Medical University and University Heart Center, Graz, Austria
| | - Markus Wallner
- Department of Internal Medicine, Medical University and University Heart Center, Graz, Austria
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | | | | | - Tobias Madl
- Gottfried Schatz Research Center, Medical University, Graz, Austria
- BioTechMed, Graz, Austria
| | - Alexander Springer
- Gottfried Schatz Research Center, Medical University, Graz, Austria
- BioTechMed, Graz, Austria
| | - Gerald Seidel
- Department of Ophthalmology, Medical University, Graz, Austria
| | - Andreas Wedrich
- Department of Ophthalmology, Medizinische Universitat, Graz, Austria
| | - Andreas Zirlik
- Department of Internal Medicine, Medical University and University Heart Center, Graz, Austria
| | - Thomas Krahn
- Department of Internal Medicine, Medical University, Graz, Austria
- Department of Pharmacology and Personalised Medicine, Maastricht University, Maastricht, The Netherlands
| | - Rudolf Stauber
- Department of Internal Medicine, Medizinische Universitat, Graz, Austria
| | - Burkert Pieske
- Department of Internal Medicine and Cardiology, Charité University Medicine, Berlin, Germany
| | - Thomas R Pieber
- Center for Biomarker Research in Medicine, Graz, Austria
- Department of Internal Medicine, Medical University, Graz, Austria
| | - Nicolas Verheyen
- Department of Internal Medicine, Medical University and University Heart Center, Graz, Austria
| | | | - Albrecht Schmidt
- Department of Internal Medicine, Medical University and University Heart Center, Graz, Austria
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Fuchs-Neuhold B, Staubmann W, Peterseil M, Rath A, Schweighofer N, Kronberger A, Riederer M, van der Kleyn M, Martin J, Hörmann-Wallner M, Waldner I, Konrad M, Aufschnaiter AL, Siegmund B, Berghold A, Holasek S, Pail E. Investigating New Sensory Methods Related to Taste Sensitivity, Preferences and Diet of Mother-Infant Pairs and its Relationship to Body Composition and Biomarkers: Protocol for an Explorative Study (Preprint). JMIR Res Protoc 2022; 11:e37279. [PMID: 35475790 PMCID: PMC9096638 DOI: 10.2196/37279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/08/2022] [Accepted: 03/23/2022] [Indexed: 11/13/2022] Open
Abstract
Background Early experiences with different flavors play an important role in infant development, including food and taste acceptance. Flavors are already perceived in utero with the development of the taste and olfactory system and are passed on to the child through breast and bottle feeding. Therefore, the first 1000 days of life are considered a critical window for infant developmental programming. Objective The objective of our study is to investigate, both in the prenatal and postnatal period, taste sensitivity, preferences, and dietary diversity of mother-infant pairs. The explorative study design will also report on the impact of these variables on body composition (BC) and biomarkers. In contrast to conventional methods, this study involves long-term follow-up data collection from mother-infant pairs; moreover, the integration of audiovisual tools for recording infants' expressions pertaining to taste stimuli is a novelty of this study. Considering these new methodological approaches, the study aims to assess taste-related data in conjunction with BC parameters like fat-free mass or fat mass, biomarkers, and nutritional intake in infants and children. Methods Healthy pregnant women aged between 18 and 50 years (BMI≥18.5 kg/m2 to ≤30 kg/m2; <28 weeks of gestation) were recruited from January 2014 to October 2014. The explorative design implies 2 center visits during pregnancy (24-28 weeks of gestation and 32-34 weeks of gestation) and 2 center visits after delivery (6-8 weeks postpartum and 14-16 weeks postpartum) as well as follow-up visits at 1, 3-3.5, and 6 years after delivery. Data collection encompasses anthropometric and biochemical measurements as well as BC analyses with air displacement plethysmography, taste perception assessments, and multicomponent questionnaires on demographics, feeding practices, and nutritional and lifestyle behaviors. Audiovisual data from infants’ reactions to sensory stimuli are collected and coded by trained staff using Baby Facial Action Coding and the Body Action Posture System. Birth outcomes and weight development are obtained from medical records, and additional qualitative data are gathered from 24 semistructured interviews. Results Our cohort represents a homogenous group of healthy women with stringent exclusion criteria. A total of 54 women met the eligibility criteria, whereas 47 mother-child pairs completed data collection at 4 center visits during and after pregnancy. Follow-up phases, data analyses, and dissemination of the findings are scheduled for the end of 2023. The study was approved by the ethics committee of the Medical University of Graz (EC No 26–066 ex 13/14), and all participants provided informed consent. Conclusions The results of this study could be useful for elucidating the connections between maternal and infant statuses regarding diet, taste, biomarkers, and prenatal and postnatal weight development. This study may also be relevant to the establishment of further diagnostic and interventional strategies targeting childhood obesity and early body fat development. International Registered Report Identifier (IRRID) DERR1-10.2196/37279
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Affiliation(s)
- Bianca Fuchs-Neuhold
- Health Perception Lab, Institute of Dietetics and Nutrition, FH JOANNEUM GmbH - University of Applied Sciences, Graz, Austria
- Otto Loewi Research Center, Medical University of Graz, Graz, Austria
| | - Wolfgang Staubmann
- Health Perception Lab, Institute of Dietetics and Nutrition, FH JOANNEUM GmbH - University of Applied Sciences, Graz, Austria
| | - Marie Peterseil
- Health Perception Lab, Institute of Dietetics and Nutrition, FH JOANNEUM GmbH - University of Applied Sciences, Graz, Austria
| | - Anna Rath
- Institute of Midwifery, FH JOANNEUM GmbH - University of Applied Sciences, Graz, Austria
| | - Natascha Schweighofer
- Institute of Biomedical Science, FH JOANNEUM GmbH - University of Applied Sciences, Graz, Austria
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, Graz, Austria
| | - Anika Kronberger
- Institute of Design and Communication, FH JOANNEUM GmbH - University of Applied Sciences, Graz, Austria
| | - Monika Riederer
- Institute of Biomedical Science, FH JOANNEUM GmbH - University of Applied Sciences, Graz, Austria
| | - Moenie van der Kleyn
- Institute of Midwifery, FH JOANNEUM GmbH - University of Applied Sciences, Graz, Austria
| | - Jochen Martin
- Institute of Design and Communication, FH JOANNEUM GmbH - University of Applied Sciences, Graz, Austria
| | - Marlies Hörmann-Wallner
- Health Perception Lab, Institute of Dietetics and Nutrition, FH JOANNEUM GmbH - University of Applied Sciences, Graz, Austria
| | - Irmgard Waldner
- Institute of Midwifery, FH JOANNEUM GmbH - University of Applied Sciences, Graz, Austria
| | - Manuela Konrad
- Health Perception Lab, Institute of Dietetics and Nutrition, FH JOANNEUM GmbH - University of Applied Sciences, Graz, Austria
| | - Anna Lena Aufschnaiter
- Health Perception Lab, Institute of Dietetics and Nutrition, FH JOANNEUM GmbH - University of Applied Sciences, Graz, Austria
| | - Barbara Siegmund
- Institute of Analytical Chemistry and Food Chemistry, Graz University of Technology, Graz, Austria
| | - Andrea Berghold
- Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz, Graz, Austria
| | - Sandra Holasek
- Otto Loewi Research Center, Medical University of Graz, Graz, Austria
| | - Elisabeth Pail
- Health Perception Lab, Institute of Dietetics and Nutrition, FH JOANNEUM GmbH - University of Applied Sciences, Graz, Austria
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Schweighofer N, Colantonio C, Haudum CW, Hutz B, Kolesnik E, Mursic I, Pilz S, Schmidt A, Stadlbauer V, Zirlik A, Pieber TR, Verheyen N, Obermayer-Pietsch B. DXA-Derived Indices in the Characterisation of Sarcopenia. Nutrients 2021; 14:186. [PMID: 35011061 PMCID: PMC8747660 DOI: 10.3390/nu14010186] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [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] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 12/27/2021] [Accepted: 12/28/2021] [Indexed: 12/18/2022] Open
Abstract
Sarcopenia is linked with increased risk of falls, osteoporosis and mortality. No consensus exists about a gold standard "dual-energy X-ray absorptiometry (DXA) index for muscle mass determination" in sarcopenia diagnosis. Thus, many indices exist, but data on sarcopenia diagnosis agreement are scarce. Regarding sarcopenia diagnosis reliability, the impact of influencing factors on sarcopenia prevalence, diagnosis agreement and reliability are almost completely missing. For nine DXA-derived muscle mass indices, we aimed to evaluate sarcopenia prevalence, diagnosis agreement and diagnosis reliability, and investigate the effects of underlying parameters, presence or type of adjustment and cut-off values on all three outcomes. The indices were analysed in the BioPersMed cohort (58 ± 9 years), including 1022 asymptomatic subjects at moderate cardiovascular risk. DXA data from 792 baselines and 684 follow-up measurements (for diagnosis agreement and reliability determination) were available. Depending on the index and cut-off values, sarcopenia prevalence varied from 0.6 to 36.3%. Height-adjusted parameters, independent of underlying parameters, showed a relatively high level of diagnosis agreement, whereas unadjusted and adjusted indices showed low diagnosis agreement. The adjustment type defines which individuals are recognised as sarcopenic in terms of BMI and sex. The investigated indices showed comparable diagnosis reliability in follow-up examinations.
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Affiliation(s)
- Natascha Schweighofer
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, 8036 Graz, Austria; (C.W.H.); (B.H.); (I.M.); (S.P.); (T.R.P.); (B.O.-P.)
- CBmed, Center for Biomarker Research in Medicine, 8010 Graz, Austria;
| | - Caterina Colantonio
- Department of Internal Medicine, Division of Cardiology, Medical University of Graz, 8036 Graz, Austria; (C.C.); (E.K.); (A.S.); (A.Z.); (N.V.)
| | - Christoph W. Haudum
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, 8036 Graz, Austria; (C.W.H.); (B.H.); (I.M.); (S.P.); (T.R.P.); (B.O.-P.)
- CBmed, Center for Biomarker Research in Medicine, 8010 Graz, Austria;
| | - Barbara Hutz
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, 8036 Graz, Austria; (C.W.H.); (B.H.); (I.M.); (S.P.); (T.R.P.); (B.O.-P.)
| | - Ewald Kolesnik
- Department of Internal Medicine, Division of Cardiology, Medical University of Graz, 8036 Graz, Austria; (C.C.); (E.K.); (A.S.); (A.Z.); (N.V.)
| | - Ines Mursic
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, 8036 Graz, Austria; (C.W.H.); (B.H.); (I.M.); (S.P.); (T.R.P.); (B.O.-P.)
| | - Stefan Pilz
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, 8036 Graz, Austria; (C.W.H.); (B.H.); (I.M.); (S.P.); (T.R.P.); (B.O.-P.)
| | - Albrecht Schmidt
- Department of Internal Medicine, Division of Cardiology, Medical University of Graz, 8036 Graz, Austria; (C.C.); (E.K.); (A.S.); (A.Z.); (N.V.)
| | - Vanessa Stadlbauer
- CBmed, Center for Biomarker Research in Medicine, 8010 Graz, Austria;
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Medical University of Graz, 8036 Graz, Austria
| | - Andreas Zirlik
- Department of Internal Medicine, Division of Cardiology, Medical University of Graz, 8036 Graz, Austria; (C.C.); (E.K.); (A.S.); (A.Z.); (N.V.)
| | - Thomas R. Pieber
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, 8036 Graz, Austria; (C.W.H.); (B.H.); (I.M.); (S.P.); (T.R.P.); (B.O.-P.)
- CBmed, Center for Biomarker Research in Medicine, 8010 Graz, Austria;
| | - Nicolas Verheyen
- Department of Internal Medicine, Division of Cardiology, Medical University of Graz, 8036 Graz, Austria; (C.C.); (E.K.); (A.S.); (A.Z.); (N.V.)
| | - Barbara Obermayer-Pietsch
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, 8036 Graz, Austria; (C.W.H.); (B.H.); (I.M.); (S.P.); (T.R.P.); (B.O.-P.)
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Riederer M, Schweighofer N, Trajanoski S, Stelzer C, Zehentner M, Fuchs-Neuhold B, Kashofer K, Mayr JA, Hörmann-Wallner M, Holasek S, van der Kleyn M. Free threonine in human breast milk is related to infant intestinal microbiota composition. Amino Acids 2021; 54:365-383. [PMID: 34477981 PMCID: PMC8948153 DOI: 10.1007/s00726-021-03057-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 07/26/2021] [Indexed: 12/19/2022]
Abstract
BACKGROUND Accumulating evidence indicates that free amino acids (FAA) might be bioactive compounds with potential immunomodulatory capabilities. However, the FAA composition in human milk is still poorly characterized with respect to its correlation to maternal serum levels and its physiological significance for the infant. Studies addressing the relation of human milk FAA to the infants' intestinal microbiota are still missing. METHODS As part of a pilot study, maternal serum and breast milk FAA concentrations as well as infant intestinal microbiota (16S rRNA) were determined 2 months after birth. The study cohort consisted of 41 healthy mothers and their term delivered, healthy infants with normal birthweight. The relationship between maternal serum and milk FAA was determined by correlation analyses. Associations between (highly correlated) milk FAA and infant intestinal beta diversity were tested using PERMANOVA, LefSe and multivariate regression models adjusted for common confounders. RESULTS Seven breast milk FAA correlated significantly with serum concentrations. One of these, threonine showed a negative association with abundance of members of the class Gammaproteobacteria (R2adj = 17.1%, p = 0.006; β= - 0.441). In addition, on the level of families and genera, threonine explained 23.2% of variation of the relative abundance of Enterobacteriaceae (R2adj; p = 0.001; β = - 0.504) and 11.1% of variability in the abundance of Escherichia/Shigella (R2adj, p = 0.025; β = - 0.368), when adjusted for confounders. CONCLUSION Our study is the first to suggest potential interactions between breast milk FAA and infant gut microbiota composition during early lactation. The results might be indicative of a potential protective role of threonine against members of the Enterobacteriaceae family in breast-fed infants. Still, results are based on correlation analyses and larger cohorts are needed to support the findings and elucidate possible underlying mechanisms to assess the complex interplay between breast milk FAA and infant intestinal microbiota in detail.
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Affiliation(s)
- Monika Riederer
- Institute of Biomedical Science, University of Applied Sciences JOANNEUM, Graz, Austria.
| | | | - Slave Trajanoski
- Core Facility Computational Bioanalytics, Center for Medical Research (ZMF), Medical University of Graz, Graz, Austria
| | - Claudia Stelzer
- Institute of Biomedical Science, University of Applied Sciences JOANNEUM, Graz, Austria
| | - Miriam Zehentner
- Institute of Biomedical Science, University of Applied Sciences JOANNEUM, Graz, Austria
| | - Bianca Fuchs-Neuhold
- Institute of Dietetics and Nutrition, Health Perception Lab, University of Applied Sciences JOANNEUM, Graz, Austria
| | - Karl Kashofer
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Auenbruggerpl. 2, 8036, Graz, Austria
| | - Johannes A Mayr
- Department of Pediatrics, Salzburger Landeskliniken and Paracelsus Medical University, Salzburg, Austria
| | - Marlies Hörmann-Wallner
- Institute of Dietetics and Nutrition, Health Perception Lab, University of Applied Sciences JOANNEUM, Graz, Austria
| | - Sandra Holasek
- Department of Pathophysiology, Medical University Graz, Graz, Austria
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Lajin B, Schweighofer N, Goessler W, Obermayer-Pietsch B. The determination of the Paraxanthine/Caffeine ratio as a metabolic biomarker for CYP1A2 activity in various human matrices by UHPLC-ESIMS/MS. Talanta 2021; 234:122658. [PMID: 34364467 DOI: 10.1016/j.talanta.2021.122658] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 06/22/2021] [Accepted: 06/23/2021] [Indexed: 11/16/2022]
Abstract
The Cytochrome P450 CYP1A2 is a central enzyme in the metabolism of drugs and xenobiotics. The overall activity of this enzyme is influenced by a complex array of biochemical, dietary, and genetic factors. One of the simplest ways to probe the overall output of CYP1A2 is to measure the ratio between the concentration of a precursor and a product of its activity. With the growing interest in the Paraxanthine/Caffeine ratio, the need arises to develop improved analytical methods specifically optimized for the rapid and sensitive determination of paraxanthine and caffeine in biological samples. We report a new optimized method for the determination of caffeine and paraxanthine in various human matrices. The method involved direct determination following protein precipitation based on ultra high performance liquid chromatographic separation with tandem mass spectrometric detection (UHPLC-ESIMS/MS). The method offers an improvement in the detection limit over previously published methods by at least 10-fold (0.1 pg), rapid chromatographic separation (ca. 5 min), the utilization of a green chromatographic solvent (5% v/v ethanol), direct determination with little sample preparation, and the employment of isotopically labeled internal standards and qualifier ions to ensure accuracy. Method validation in urine, saliva, and plasma was performed by spiking at various concentration levels where the recovery and repeatability were within ±15% and ±10%, respectively. The method was applied to investigate the levels of caffeine and paraxanthine in volunteers following controlled caffeine administration and to investigate the inter- and intra-individual variability in the paraxanthine/caffeine ratio in volunteers following an unrestricted caffeine diet. In conclusion, the developed UHPLC-ESIMS/MS method is optimized specifically for the simultaneous determination of the paraxanthine/caffeine ratio in multiple biological matrices, offers several advantages over the current methods, and is well suitable for application in large clinical studies.
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Affiliation(s)
- Bassam Lajin
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria.
| | - Natascha Schweighofer
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria; CBmed, Center for Biomarker Research in Medicine, Stiftingtalstrasse 5, 8010, Graz, Austria
| | - Walter Goessler
- Institute of Chemistry, Analytical Chemistry for the Health and Environment, University of Graz, Universitaetsplatz 1, 8010, Graz, Austria
| | - Barbara Obermayer-Pietsch
- Division of Endocrinology and Diabetology, Endocrinology Lab Platform, Department of Internal Medicine and Gynecology and Obstetrics, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria
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Schweighofer N, Strasser M, Haudum C, Schmidt A, Pieber T, Obermayer-Pietsch B. Characterisation of sarcopenia via DXA measured muscle/fat mass parameters and uc-dpMGP serum levels. Bone Rep 2021. [DOI: 10.1016/j.bonr.2021.100874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Riederer M, Wallner M, Schweighofer N, Fuchs-Neuhold B, Rath A, Berghold A, Eberhard K, Groselj-Strele A, Staubmann W, Peterseil M, Waldner I, Mayr JA, Rothe M, Holasek S, Maunz S, Pail E, van der Kleyn M. Distinct maternal amino acids and oxylipins predict infant fat mass and fat-free mass indices. Arch Physiol Biochem 2020; 129:563-574. [PMID: 33283558 DOI: 10.1080/13813455.2020.1846204] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Interested in maternal determinants of infant fat mass index (FMI) and fat-free mass index (FFMI), considered as predictors for later development of obesity, we analysed amino acids (AA) and oxylipins in maternal serum and breast milk (BM). FMI and FFMI were calculated in 47 term infants aged 4 months (T4). Serum AA were analysed in pregnancy (T1, T2) and 6-8 weeks postpartum (T3). At T3, AA and oxylipins were analysed in BM. Biomarker-index-associations were identified by regression analysis. Infant FMI (4.1 ± 1.31 kg/m2; MW ± SD) was predicted by T2 proline (R2 adj.: 7.6%, p = .036) and T3 BM 11-hydroxy-eicosatetraenoic-acid (11-HETE) and 13-hydroxy-docosahexaenoic-acid (13-HDHA; together:35.5% R2 adj., p < .001). Maternal peripartum antibiotics (AB) emerged as confounders (+AB: 23.5% higher FMI; p = .025). Infant FFMI (12.1 ± 1.19 kg/m2; MW ± SD) was predicted by histidine (R2 adj.: 14.5%, p < .001) and 17-HDHA (BM, R2 adj.:19.3%, p < .001), determined at T3. Confirmed in a larger cohort, the parameters could elucidate connections between maternal metabolic status, nutrition, and infant body development.
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Affiliation(s)
- Monika Riederer
- Institute of Biomedical Science, University of Applied Sciences JOANNEUM, Graz, Austria
| | - Marlies Wallner
- Institute of Dietetics and Nutrition, Health Perception Lab, University of Applied Sciences JOANNEUM, Graz, Austria
| | | | - Bianca Fuchs-Neuhold
- Institute of Dietetics and Nutrition, Health Perception Lab, University of Applied Sciences JOANNEUM, Graz, Austria
| | - Anna Rath
- Institute of Midwifery, University of Applied Sciences JOANNEUM, Graz, Austria
| | - Andrea Berghold
- Institute for Medical Informatics, Statistics and Documentation, Medical University Graz, Graz, Austria
| | - Katharina Eberhard
- Core Facility Computational Bioanalytics, Center for Medical Research (ZMF), Medical University of Graz, Graz, Austria
| | - Andrea Groselj-Strele
- Core Facility Computational Bioanalytics, Center for Medical Research (ZMF), Medical University of Graz, Graz, Austria
| | - Wolfgang Staubmann
- Institute of Dietetics and Nutrition, Health Perception Lab, University of Applied Sciences JOANNEUM, Graz, Austria
| | - Marie Peterseil
- Institute of Dietetics and Nutrition, Health Perception Lab, University of Applied Sciences JOANNEUM, Graz, Austria
| | - Irmgard Waldner
- Institute of Midwifery, University of Applied Sciences JOANNEUM, Graz, Austria
| | - Johannes A Mayr
- University Clinic for Pediatrics and Adolescent Medicine Salzburg, Salzburg, Austria
| | | | - Sandra Holasek
- Department of Pathophysiology, Medical University Graz, Graz, Austria
| | - Susanne Maunz
- Institute of Dietetics and Nutrition, Health Perception Lab, University of Applied Sciences JOANNEUM, Graz, Austria
| | - Elisabeth Pail
- Institute of Dietetics and Nutrition, Health Perception Lab, University of Applied Sciences JOANNEUM, Graz, Austria
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Schweighofer N, Strasser M, Haudum CW, Schmidt A, Mursic I, Pieske B, Pieber TR, Obermayer-Pietsch B. Body composition and anthropometric data - influence of total and uc-dpMGP. Bone Rep 2020. [DOI: 10.1016/j.bonr.2020.100480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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11
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Schweighofer N, Strasser M, Haudum CW, Schmidt A, Kolesnik E, Pieske B, Pieber TR, Obermayer-Pietsch B. Total versus uc-dpMGP: Associations with cardiovascular parameters. Bone Rep 2020. [DOI: 10.1016/j.bonr.2020.100481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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12
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Schweighofer N, Genser B, Maerz W, Kleber ME, Trummer O, Pieber TR, Obermayer-Pietsch B. Intronic Variants in OCT1 are Associated with All-Cause and Cardiovascular Mortality in Metformin Users with Type 2 Diabetes. Diabetes Metab Syndr Obes 2020; 13:2069-2080. [PMID: 32606866 PMCID: PMC7308180 DOI: 10.2147/dmso.s235663] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 05/01/2020] [Indexed: 12/16/2022] Open
Abstract
PURPOSE Organic cation transporters (Octs) use cations like endogenous compounds, toxins, and drugs, such as metformin, as substrates. Therefore, these proteins determine the pharmacokinetics and -dynamics of metformin and thus its efficacy. Of note, metformin is today the most commonly used pharmaceutical in the treatment of type 2 diabetes (T2DM) with nevertheless a great variability in clinical response, which attributes to genetic variances. The aim of this study was to determine the influence of intronic OCT1 SNPs on prevalence of all-cause and cardiovascular death. PATIENTS AND METHODS Genotypes of 27 intronic SNPs in OCT1 were investigated in the LURIC study, a prospective cohort of 3316 participants scheduled for coronary angiography. We investigated whether these variants were associated with all-cause and cardiovascular death in 73 individuals with T2DM under metformin therapy, in individuals without diabetes, individuals with T2DM and individuals with T2DM without metformin therapy. RESULTS In a multivariate Cox regression analysis adjusted for classical cardiovascular risk factors, 4 intronic OCT1 SNPs were significantly associated with all-cause and cardiovascular mortality in individuals with T2DM on metformin therapy. CONCLUSION According to their OCT1 genotype, some individuals with T2DM on metformin therapy might be prone to an increased risk of cardiovascular death.
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Affiliation(s)
- Natascha Schweighofer
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University Graz, Graz, Austria
- CBmed GmbH, Center for Biomarker Research in Medicine, Graz, Austria
| | - Bernd Genser
- BG Stats Consulting, Vienna, Austria
- Institute of Public Health, Social and Preventive Medicine, Medical Faculty of Mannheim, University of Heidelberg, Mannheim, Germany
| | - Winfried Maerz
- Medical Clinic V (Nephrology, Hypertensiology, Rheumatology, Endocrinology, Diabetology), Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
- SynLaboratory Academy, SynLaboratory Holding Deutschland GmbH, Mannheim and Augsburg, Germany
| | - Marcus E Kleber
- Medical Clinic V (Nephrology, Hypertensiology, Rheumatology, Endocrinology, Diabetology), Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Olivia Trummer
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University Graz, Graz, Austria
| | - Thomas R Pieber
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University Graz, Graz, Austria
- CBmed GmbH, Center for Biomarker Research in Medicine, Graz, Austria
| | - Barbara Obermayer-Pietsch
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University Graz, Graz, Austria
- CBmed GmbH, Center for Biomarker Research in Medicine, Graz, Austria
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13
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Trummer O, Schweighofer N, Haudum CW, Trummer C, Pilz S, Theiler-Schwetz V, Keppel MH, Grübler M, Pieber TR, Renner W, Obermayer-Pietsch B, Lerchbaum E. Genetic Components of 25-Hydroxyvitamin D Increase in Three Randomized Controlled Trials. J Clin Med 2020; 9:jcm9020570. [PMID: 32093012 PMCID: PMC7074051 DOI: 10.3390/jcm9020570] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/11/2020] [Accepted: 02/14/2020] [Indexed: 12/30/2022] Open
Abstract
The 25-Hydroxyvitamin D (25[OH)D) serum concentration depends on vitamin D intake, endogenous vitamin D production and genetic factors. The latter have been demonstrated in large genome-wide association studies indicating that single nucleotide polymorphisms (SNPs) in genes related to the vitamin D metabolism are as important for serum 25(OH)D levels as the influence of season. The mechanism on how these SNPs influence serum 25(OH)D levels are still unclear. The aim of the present study was to investigate the genetic effects of ten selected SNPs related to vitamin D metabolism on 25-hydroxyvitamin D increase (∆25(OH)D) after vitamin D supplementation in three randomized controlled trials. Genotypes of SNPs related to vitamin D metabolism were determined in 411 participants with 25(OH)D concentrations < 75 nmol/l receiving 20,000 IU cholecalciferol per week for 8 or 12 weeks after study inclusion. For the vitamin D receptor (VDR) rs10783219 polymorphism, the minor A-allele was associated with lower ∆25(OH)D values in the entire study population (p = 0.022), which was not consistent in all three cohorts when analysed separately. VDR rs10783219 might therefore be a genetic modulator of increasing 25-hydroxyvitamin D concentrations. Considering the wide-spread use of vitamin D supplementation, future large and well-designed randomized controlled trials (RCTs) should investigate the clinical impact of this polymorphism.
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Affiliation(s)
- Olivia Trummer
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria; (N.S.); (C.W.H.); (C.T.); (S.P.); (V.T.-S.); (M.G.); (T.R.P.); (B.O.-P.); (E.L.)
- Correspondence: ; Tel.: +43-316-385-72935
| | - Natascha Schweighofer
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria; (N.S.); (C.W.H.); (C.T.); (S.P.); (V.T.-S.); (M.G.); (T.R.P.); (B.O.-P.); (E.L.)
- Center for Biomarker Research in Medicine, CBmed, 8010 Graz, Austria
| | - Christoph W. Haudum
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria; (N.S.); (C.W.H.); (C.T.); (S.P.); (V.T.-S.); (M.G.); (T.R.P.); (B.O.-P.); (E.L.)
- Center for Biomarker Research in Medicine, CBmed, 8010 Graz, Austria
| | - Christian Trummer
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria; (N.S.); (C.W.H.); (C.T.); (S.P.); (V.T.-S.); (M.G.); (T.R.P.); (B.O.-P.); (E.L.)
| | - Stefan Pilz
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria; (N.S.); (C.W.H.); (C.T.); (S.P.); (V.T.-S.); (M.G.); (T.R.P.); (B.O.-P.); (E.L.)
| | - Verena Theiler-Schwetz
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria; (N.S.); (C.W.H.); (C.T.); (S.P.); (V.T.-S.); (M.G.); (T.R.P.); (B.O.-P.); (E.L.)
| | - Martin H. Keppel
- Department of Laboratory Medicine, Paracelsus Medical University Salzburg, 5020 Salzburg, Austria;
| | - Martin Grübler
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria; (N.S.); (C.W.H.); (C.T.); (S.P.); (V.T.-S.); (M.G.); (T.R.P.); (B.O.-P.); (E.L.)
| | - Thomas R. Pieber
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria; (N.S.); (C.W.H.); (C.T.); (S.P.); (V.T.-S.); (M.G.); (T.R.P.); (B.O.-P.); (E.L.)
- Center for Biomarker Research in Medicine, CBmed, 8010 Graz, Austria
| | - Wilfried Renner
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, 8036 Graz, Austria;
| | - Barbara Obermayer-Pietsch
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria; (N.S.); (C.W.H.); (C.T.); (S.P.); (V.T.-S.); (M.G.); (T.R.P.); (B.O.-P.); (E.L.)
| | - Elisabeth Lerchbaum
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria; (N.S.); (C.W.H.); (C.T.); (S.P.); (V.T.-S.); (M.G.); (T.R.P.); (B.O.-P.); (E.L.)
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Bakhti K, Mottet D, Schweighofer N, Froger J, Laffont I. Proximal arm non-use when reaching after a stroke. Neurosci Lett 2017; 657:91-96. [DOI: 10.1016/j.neulet.2017.07.055] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 07/07/2017] [Accepted: 07/30/2017] [Indexed: 11/25/2022]
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15
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Ulbing M, Kirsch AH, Leber B, Lemesch S, Münzker J, Schweighofer N, Hofer D, Trummer O, Rosenkranz AR, Müller H, Eller K, Stadlbauer V, Obermayer-Pietsch B. MicroRNAs 223-3p and 93-5p in patients with chronic kidney disease before and after renal transplantation. Bone 2017; 95:115-123. [PMID: 27866993 PMCID: PMC6326349 DOI: 10.1016/j.bone.2016.11.016] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 10/24/2016] [Accepted: 11/16/2016] [Indexed: 01/18/2023]
Abstract
Chronic kidney disease (CKD) is associated with a multifactorial dysregulation of bone and vascular calcification and closely linked to increased cardiovascular mortality and concomitant bone disease. We aimed to investigate specific microRNA (miRNA) signatures in CKD patients to find indicators for vascular calcification and/or bone mineralization changes during CKD and after kidney transplantation (KT). A miRNA array was used to investigate serum miRNA profiles in CKD patients, then selected miRNAs were quantified in a validation cohort comprising 73 patients in CKD stages 3 to 5, 67 CKD patients after KT, and 36 healthy controls. A spectrum of biochemical parameters including markers for kidney function, inflammation, glucose, and mineral metabolism was determined. The relative expression of miR-223-3p and miR-93-5p was down-regulated in patients with CKD stage 4 and 5 compared to healthy controls. This down-regulation disappeared after kidney transplantation even when lower glomerular filtration rates (eGFR) persisted. MiR-223-3p and miR-93-5p were associated with interleukin-6 (IL-6) and eGFR levels, and by trend with interleukin-8 (IL-8), C-peptide, hematocrit, and parathyroid hormone (PTH). This study contributes new knowledge of serum miRNA expression profiles in CKD, potentially reflecting pathophysiological changes of bone and calcification pathways associated with inflammation, vascular calcification, mineral and glucose metabolism. Identified miRNA signatures can contribute to future risk markers or future therapeutic targets in bone and kidney disease.
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Affiliation(s)
- M Ulbing
- Dept. of Internal Medicine, Clinical Division of Endocrinology and Diabetology, Medical University of Graz, Austria.
| | - A H Kirsch
- Dept. of Internal Medicine, Clinical Division of Nephrology, Medical University of Graz, Austria
| | - B Leber
- Dept. of Surgery, Clinical Division of Transplantation Surgery, Medical University of Graz, Austria
| | - S Lemesch
- Dept. of Internal Medicine, Clinical Division of Gastroenterology and Hepatology, Medical University of Graz, Austria
| | - J Münzker
- Dept. of Internal Medicine, Clinical Division of Endocrinology and Diabetology, Medical University of Graz, Austria
| | - N Schweighofer
- Dept. of Internal Medicine, Clinical Division of Endocrinology and Diabetology, Medical University of Graz, Austria
| | - D Hofer
- Dept. of Internal Medicine, Clinical Division of Endocrinology and Diabetology, Medical University of Graz, Austria
| | - O Trummer
- Dept. of Internal Medicine, Clinical Division of Endocrinology and Diabetology, Medical University of Graz, Austria
| | - A R Rosenkranz
- Dept. of Internal Medicine, Clinical Division of Nephrology, Medical University of Graz, Austria
| | - H Müller
- Dept. of Surgery, Clinical Division of Transplantation Surgery, Medical University of Graz, Austria
| | - K Eller
- Dept. of Internal Medicine, Clinical Division of Nephrology, Medical University of Graz, Austria
| | - V Stadlbauer
- Dept. of Internal Medicine, Clinical Division of Gastroenterology and Hepatology, Medical University of Graz, Austria.
| | - B Obermayer-Pietsch
- Dept. of Internal Medicine, Clinical Division of Endocrinology and Diabetology, Medical University of Graz, Austria
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16
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Schwetz V, Lerchbaum E, Schweighofer N, Hacker N, Trummer O, Borel O, Pieber TR, Chapurlat R, Obermayer-Pietsch B. Osteocalcin levels on oral glucose load in women being investigated for polycystic ovary syndrome. Endocr Pract 2016; 20:5-14. [PMID: 24013985 DOI: 10.4158/ep13110.or] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Osteocalcin (OC) might play a hormone-like role in energy metabolism and the regulatory circuit between the pancreas and osteoblasts. Effects of a 75-g oral glucose tolerance test (OGTT) on total OC, undercarboxylated (ucOC), and carboxylated osteocalcin (cOC) in insulin-resistant (IR) and noninsulin-resistant (nIR) premenopausal women was evaluated, and the relationships of changes in OC, ucOC, and cOC with area under the curve (AUC) insulin and the Matsuda index were examined. METHODS In this cross-sectional study, 105 premenopausal women underwent OGTT; 18 were IR (homeostatic model assessment of insulin resistance [HOMA-IR] > 2.6; (2 with type 2 diabetes, 2 with impaired glucose tolerance), and 87 were nIR (3 with impaired glucose tolerance). Changes in total OC, ucOC, and cOC were evaluated 60 and 120 minutes after glucose loading. RESULTS At baseline, IR subjects had significantly lower levels of total OC, cOC, and ucOC. In nIR women, total OC decreased by 19% from 18.0 ng/mL (14.5-24.7) at baseline to 14.6 ng/mL (10.9-17.8) after 120 minutes, ucOC decreased by 22% from 3.2 ng/mL (2.1-4.5) to 2.5 ng/mL (1.7-3.5), and cOC decreased by 26% from 14.9 ng/mL (12.1-20.4) to 11.1 ng/mL (9.0-14.5) (P < .001, respectively). No significant decreases were noted in IR subjects. The declines in OC and cOC predicted AUCinsulin (ΔOC: β = 0.301, P = .001; ΔcOC: β = 0.315, P < .001) and the Matsuda index (ΔOC: β = -0.235, P = .003; ΔcOC: β = -0.245, P = .002). CONCLUSIONS Glucose intake lowers levels of OC, ucOC, and cOC in nIR women, the extent of which predicts IR and insulin sensitivity in premenopausal women. OC parameters seem suppressed in IR women. There might be a differential osteoblast response to oral glucose in IR and nIR women, with OC reflecting this finding.
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Affiliation(s)
- Verena Schwetz
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Elisabeth Lerchbaum
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Natascha Schweighofer
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Nicole Hacker
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Olivia Trummer
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Olivier Borel
- Hôpital Edouard Herriot, Université de Lyon, INSERM UMR 1033, France
| | - Thomas R Pieber
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Roland Chapurlat
- Hôpital Edouard Herriot, Université de Lyon, INSERM UMR 1033, France
| | - Barbara Obermayer-Pietsch
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Graz, Austria
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Schweighofer N, Aigelsreiter A, Trummer O, Graf-Rechberger M, Hacker N, Kniepeiss D, Wagner D, Stiegler P, Trummer C, Pieber T, Obermayer-Pietsch B, Müller H. Direct comparison of regulators of calcification between bone and vessels in humans. Bone 2016; 88:31-38. [PMID: 27108945 DOI: 10.1016/j.bone.2016.04.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 11/30/2015] [Accepted: 04/16/2016] [Indexed: 01/16/2023]
Abstract
Calcification is not only physiologically present in bone but is a main pathophysiological process in vasculature, favouring cardiovascular diseases. Our aim was to investigate changes in the expression of calcification regulators during vascular calcification in bone and vasculature. Levels of gene expression of osteoprotegerin (OPG), receptor activator of NF-κB ligand (RANKL), osteopontin (OPN), matrix gla protein (MGP), bone sialoprotein (BSP), SMAD6, and runt-related transcription factor 2 (RUNX2) were determined in bone, aorta, and external iliac artery tissue samples of transplant donors. Histological stages of atherosclerosis (AS) in vessels are defined as "no changes", "intima thickening", or "intima calcification". Patients' bone samples were subgrouped accordingly. We demonstrate that in vessels BSP and OPN expression significantly increased during intima thickening and decreased during intima calcification, whereas the expression of regulators of calcification did not significantly change in bone during intima thickening and intima calcification. At the stage of intima thickening, MGP, OPG, and SMAD6 expression and at stage of intima calcification only MGP expression was lower in bone than in vessel. The expression of BSP and RANKL was regulated in opposite ways in bone and vessels, whereas the expression of MGP, OC, RUNX2, and OPN was regulated in a tissue-specific manner. Our study is the first direct comparison of gene expression changes during AS progression in bone and vessels. Our results indicate that changes in the expression of regulators of calcification in the vessel wall as well as in bone occur early in the calcification process, even prior to deposition of calcium/phosphate precipitation.
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Affiliation(s)
- N Schweighofer
- Department of Internal Medicine, Divison of Endocrinology and Diabetology, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - A Aigelsreiter
- Institute of Pathology, Medical University of Graz, Auenbruggerplatz 25, 8036 Graz, Austria
| | - O Trummer
- Department of Internal Medicine, Divison of Endocrinology and Diabetology, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - M Graf-Rechberger
- Institute of Pathology, Medical University of Graz, Auenbruggerplatz 25, 8036 Graz, Austria
| | - N Hacker
- Department of Internal Medicine, Divison of Endocrinology and Diabetology, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - D Kniepeiss
- Department of Surgery, Division of Transplantation Surgery, Medical University of Graz, Auenbruggerplatz 29, 8036 Graz, Austria
| | - D Wagner
- Department of Surgery, Division of Transplantation Surgery, Medical University of Graz, Auenbruggerplatz 29, 8036 Graz, Austria
| | - P Stiegler
- Department of Surgery, Division of Transplantation Surgery, Medical University of Graz, Auenbruggerplatz 29, 8036 Graz, Austria
| | - C Trummer
- Department of Internal Medicine, Divison of Endocrinology and Diabetology, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - T Pieber
- Department of Internal Medicine, Divison of Endocrinology and Diabetology, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria; Joanneum Research Health, Elisabethstrasse 5, 8010 Graz, Austria
| | - B Obermayer-Pietsch
- Department of Internal Medicine, Divison of Endocrinology and Diabetology, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria.
| | - H Müller
- Department of Surgery, Division of Transplantation Surgery, Medical University of Graz, Auenbruggerplatz 29, 8036 Graz, Austria
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18
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Bakhti K, Mottet D, Schweighofer N, Froger J, Laffont I. Quantification of learned non-use of the upper limb after a stroke. Ann Phys Rehabil Med 2015. [DOI: 10.1016/j.rehab.2015.07.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
PURPOSE OF REVIEW Polycystic ovary syndrome (PCOS) is a very common endocrine disease in women all over the world. A variety of symptoms such as hirsutism and hyperandrogenism, irregular menstrual cycles and anovulatory infertility together with metabolic dysfunction, insulin resistance, and type 2 diabetes mellitus in lean and obese individuals and the development of consecutive diseases are key problems in this heterogeneous syndrome. RECENT FINDINGS Disease-modifying and potentially disease-causing candidate genes are described. A number of genetic associations have been investigated, whereby genes related to normal-weight insulin resistance and chronic inflammation are of central interest for PCOS pathomechanisms. New insights in the pharmacogenetics of PCOS might help to individualize therapeutic options. SUMMARY Enormous progress has been made in the genetics of insulin resistance in PCOS. However, because of the individual heterogeneity of PCOS and the lack of evident functional studies, the syndrome is only partly understood to date. Large studies on selected phenotypes and therapy aspects are ongoing.
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Affiliation(s)
- Barbara Obermayer-Pietsch
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Graz, Austria
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Laffont I, Bakhti K, Coroian F, van Dokkum L, Mottet D, Schweighofer N, Froger J. Innovative technologies applied to sensorimotor rehabilitation after stroke. Ann Phys Rehabil Med 2014; 57:543-551. [PMID: 25261273 DOI: 10.1016/j.rehab.2014.08.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Accepted: 08/10/2014] [Indexed: 10/24/2022]
Abstract
Innovative technologies for sensorimotor rehabilitation after stroke have dramatically increased these past 20 years. Based on a review of the literature on "Medline" and "Web of Science" between 1990 and 2013, we offer an overview of available tools and their current level of validation. Neuromuscular electric stimulation and/or functional electric stimulation are widely used and highly suspected of being effective in upper or lower limb stroke rehabilitation. Robotic rehabilitation has yielded various results in the literature. It seems to have some effect on functional capacities when used for the upper limb. Its effectiveness in gait training is more controversial. Virtual reality is widely used in the rehabilitation of cognitive and motor impairments, as well as posture, with admitted benefits. Non-invasive brain stimulation (rTMS and TDCS) are promising in this indication but clinical evidence of their effectiveness is still lacking. In the same manner, these past five years, neurofeedback techniques based on brain signal recordings have emerged with a special focus on their therapeutic relevance in rehabilitation. Technological devices applied to rehabilitation are revolutionizing our clinical practices. Most of them are based on advances in neurosciences allowing us to better understand the phenomenon of brain plasticity, which underlies the effectiveness of rehabilitation. The acceptation and "real use" of those devices is still an issue since most of them are not easily available in current practice.
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Affiliation(s)
- I Laffont
- Département de médecine physique et de réadaptation, hôpital Lapeyronie, CHU de Montpellier, 191, boulevard du Doyen-Gaston-Giraud, 34295 Montpellier cedex 5, France; Movement to Health, Euromov, université Montpellier 1, 700, avenue du Pic-Saint-Loup, 34090 Montpellier, France.
| | - K Bakhti
- Département de médecine physique et de réadaptation, hôpital Lapeyronie, CHU de Montpellier, 191, boulevard du Doyen-Gaston-Giraud, 34295 Montpellier cedex 5, France; Movement to Health, Euromov, université Montpellier 1, 700, avenue du Pic-Saint-Loup, 34090 Montpellier, France
| | - F Coroian
- Département de médecine physique et de réadaptation, hôpital Lapeyronie, CHU de Montpellier, 191, boulevard du Doyen-Gaston-Giraud, 34295 Montpellier cedex 5, France; Movement to Health, Euromov, université Montpellier 1, 700, avenue du Pic-Saint-Loup, 34090 Montpellier, France
| | - L van Dokkum
- Département de médecine physique et de réadaptation, hôpital Lapeyronie, CHU de Montpellier, 191, boulevard du Doyen-Gaston-Giraud, 34295 Montpellier cedex 5, France; Movement to Health, Euromov, université Montpellier 1, 700, avenue du Pic-Saint-Loup, 34090 Montpellier, France
| | - D Mottet
- Movement to Health, Euromov, université Montpellier 1, 700, avenue du Pic-Saint-Loup, 34090 Montpellier, France
| | - N Schweighofer
- Movement to Health, Euromov, université Montpellier 1, 700, avenue du Pic-Saint-Loup, 34090 Montpellier, France; Computational Neuro-Rehabilitation Laboratory, University of Southern California, 1540 Alcazar Street, CHP 155, Los Angeles, CA 90089-9006, USA
| | - J Froger
- Movement to Health, Euromov, université Montpellier 1, 700, avenue du Pic-Saint-Loup, 34090 Montpellier, France; Département de médecine physique et de réadaptation, hôpital universitaire de rééducation et de réadaptation, CHU de Nîmes, Le Boucanet, 30240 Le-Grau-du-Roi, France
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Rossmann C, Windpassinger C, Brunner D, Kovacevic A, Schweighofer N, Malli R, Schuligoi R, Prokesch A, Kluve-Beckerman B, Graier WF, Kratky D, Sattler W, Malle E. Characterization of rat serum amyloid A4 (SAA4): a novel member of the SAA superfamily. Biochem Biophys Res Commun 2014; 450:1643-9. [PMID: 25044109 PMCID: PMC4145149 DOI: 10.1016/j.bbrc.2014.07.054] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 07/11/2014] [Indexed: 11/16/2022]
Abstract
The full length rat SAA4 (rSAA4) mRNA was characterized by rapid amplification of cDNA ends. rSAA4 mRNA has 1830 bases including a GA dinucleotide tandem repeat in the 5′UTR. Three consecutive C/EBP promoter elements are crucial for transcription of rSAA4. rSAA4 is abundantly expressed in the liver on mRNA and protein level.
The serum amyloid A (SAA) family of proteins is encoded by multiple genes, which display allelic variation and a high degree of homology in mammals. The SAA1/2 genes code for non-glycosylated acute-phase SAA1/2 proteins, that may increase up to 1000-fold during inflammation. The SAA4 gene, well characterized in humans (hSAA4) and mice (mSaa4) codes for a SAA4 protein that is glycosylated only in humans. We here report on a previously uncharacterized SAA4 gene (rSAA4) and its product in Rattus norvegicus, the only mammalian species known not to express acute-phase SAA. The exon/intron organization of rSAA4 is similar to that reported for hSAA4 and mSaa4. By performing 5′- and 3′RACE, we identified a 1830-bases containing rSAA4 mRNA (including a GA-dinucleotide tandem repeat). Highest rSAA4 mRNA expression was detected in rat liver. In McA-RH7777 rat hepatoma cells, rSAA4 transcription was significantly upregulated in response to LPS and IL-6 while IL-1α/β and TNFα were without effect. Luciferase assays with promoter-truncation constructs identified three proximal C/EBP-elements that mediate expression of rSAA4 in McA-RH7777 cells. In line with sequence prediction a 14-kDa non-glycosylated SAA4 protein is abundantly expressed in rat liver. Fluorescence microscopy revealed predominant localization of rSAA4-GFP-tagged fusion protein in the ER.
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Affiliation(s)
- Christine Rossmann
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | | | - Daniela Brunner
- Institute of Human Genetics, Medical University of Graz, Graz, Austria
| | - Alenka Kovacevic
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Natascha Schweighofer
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Roland Malli
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Rufina Schuligoi
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
| | - Andreas Prokesch
- Institute of Cell Biology, Histology and Embryology, Medical University of Graz, Graz, Austria; Institute of Biochemistry, Graz University of Technology, Graz, Austria
| | - Barbara Kluve-Beckerman
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Wolfgang F Graier
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Dagmar Kratky
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Wolfgang Sattler
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Ernst Malle
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria.
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Lam UD, Lerchbaum E, Schweighofer N, Trummer O, Eberhard K, Genser B, Pieber TR, Obermayer-Pietsch B. Association of MEP1A gene variants with insulin metabolism in central European women with polycystic ovary syndrome. Gene 2014; 537:245-52. [DOI: 10.1016/j.gene.2013.12.055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 11/25/2013] [Accepted: 12/23/2013] [Indexed: 10/25/2022]
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Schweighofer N, Lerchbaum E, Trummer O, Schwetz V, Pieber T, Obermayer-Pietsch B. Metformin resistance alleles in polycystic ovary syndrome: pattern and association with glucose metabolism. Pharmacogenomics 2014; 15:305-17. [DOI: 10.2217/pgs.13.223] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Insulin-sensitizer treatment with metformin is common in polycystic ovary syndrome (PCOS). OCT alleles were investigated in PCOS patients to identify genetic ‘bad responders’ and ‘nonresponders’ to metformin including their possible effects on glucose metabolism without treatment. We genotyped eight SNPs in OCT1, OCT2 and ATM genes in 676 women with PCOS and 90 control women, we also measured oral glucose tolerance tests prior to treatment. Nonfunctional alleles were present in 29.8% and low-functional alleles in 57.9% of our PCOS cohort. OCT variants were significantly associated with elevated baseline and glucose-induced C-peptide levels in PCOS. Metformin bad responders or nonresponders based on OCT genotypes might be relevant in clinical practice – their modulation of metformin pharmacokinetics and pharmacodynamics and metformin-independent glucose effects remain to be elucidated. Original submitted 7 June 2013; Revision submitted 28 October 2013
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Affiliation(s)
- Natascha Schweighofer
- Division of Endocrinology & Metabolism, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Elisabeth Lerchbaum
- Division of Endocrinology & Metabolism, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Olivia Trummer
- Division of Endocrinology & Metabolism, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Verena Schwetz
- Division of Endocrinology & Metabolism, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Thomas Pieber
- Division of Endocrinology & Metabolism, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Barbara Obermayer-Pietsch
- Division of Endocrinology & Metabolism, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
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24
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Schweighofer N, Mottet D, Bakhti K, Reinkensmeyer D, Rémy Néris O, Laffont I. Intérêt de l’analyse cinématique du point de travail et de l’étude des synergies articulaires dans l’évaluation de la récupération du membre supérieur à la phase subaiguë d’un AVC. Ann Phys Rehabil Med 2013. [DOI: 10.1016/j.rehab.2013.07.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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25
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Schweighofer N, Mottet D, Bakhti K, Reinkensmeyer D, Rémy Néris O, Laffont I. Hand and joint kinematics: Significance for the assessment of recovery in the sub-acute phase post-stroke. Ann Phys Rehabil Med 2013. [DOI: 10.1016/j.rehab.2013.07.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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26
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Schwetz V, Gumpold R, Graupp M, Hacker N, Schweighofer N, Trummer O, Pieber TR, Ballon M, Lerchbaum E, Obermayer-Pietsch B. Osteocalcin is not a strong determinant of serum testosterone and sperm count in men from infertile couples. Andrology 2013; 1:590-4. [DOI: 10.1111/j.2047-2927.2013.00095.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 04/10/2013] [Accepted: 04/16/2013] [Indexed: 12/14/2022]
Affiliation(s)
- V. Schwetz
- Division of Endocrinology and Metabolism; Department of Internal Medicine; Medical University of Graz; Graz; Austria
| | - R. Gumpold
- Division of Endocrinology and Metabolism; Department of Internal Medicine; Medical University of Graz; Graz; Austria
| | - M. Graupp
- Department of Otorhinolaryngology; Medical University of Graz; Graz; Austria
| | - N. Hacker
- Division of Endocrinology and Metabolism; Department of Internal Medicine; Medical University of Graz; Graz; Austria
| | - N. Schweighofer
- Division of Endocrinology and Metabolism; Department of Internal Medicine; Medical University of Graz; Graz; Austria
| | - O. Trummer
- Division of Endocrinology and Metabolism; Department of Internal Medicine; Medical University of Graz; Graz; Austria
| | - T. R. Pieber
- Division of Endocrinology and Metabolism; Department of Internal Medicine; Medical University of Graz; Graz; Austria
| | - M. Ballon
- Department of Obstetrics and Gynecology; Medical University of Graz; Graz; Austria
| | - E. Lerchbaum
- Division of Endocrinology and Metabolism; Department of Internal Medicine; Medical University of Graz; Graz; Austria
| | - B. Obermayer-Pietsch
- Division of Endocrinology and Metabolism; Department of Internal Medicine; Medical University of Graz; Graz; Austria
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Schweighofer N, Lerchbaum E, Trummer O, Schwetz V, Pilz S, Pieber TR, Obermayer-Pietsch B. Androgen levels and metabolic parameters are associated with a genetic variant of F13A1 in women with polycystic ovary syndrome. Gene 2012; 504:133-9. [PMID: 22565190 DOI: 10.1016/j.gene.2012.04.050] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 03/08/2012] [Accepted: 04/18/2012] [Indexed: 12/31/2022]
Abstract
The polycystic ovary syndrome (PCOS), characterized by hyperandrogenism, is one of the most common hormonal disorders among premenopausal women and is associated with infertility, obesity, and insulin resistance. Accumulating evidence suggests a role of the blood coagulation factor gene F13A1 in obesity (GeneBank ID: NM_000129.3). The aim of this study was to investigate the association of intronic allelic variants of the F13A1 gene with PCOS susceptibility and metabolic parameters in lean and obese PCOS women. In a case-control study, we determined an intronic F13A1 single nucleotide polymorphism (SNP) (dbSNP ID: rs7766109) in 585 PCOS and 171 control women and tested for PCOS susceptibility and associations with anthropometric, metabolic and hormonal parameters. Genotype frequencies of the F13A1 SNP rs7766109 were equivalent in PCOS and control women. In PCOS women, F13A1 gene variants were significantly associated with body mass index (BMI) (p=0.013), systolic blood pressure (p=0.042), insulin response (AUCins) (p=0.015), triglycerides (TG) (p=0.001), and high density lipoprotein cholesterol (HDL) (p=0.012). In the subgroup of obese PCOS women free androgen index (FAI), free testosterone and sex hormone binding globulin (SHBG) as well as glucose measurements showed a significantly different pattern across F13A1 gene variants (p=0.043; p=0.039 and p=0.013, respectively). We report for the first time an association of the F13A1 SNP rs7766109 with BMI, androgens, and insulin resistance in PCOS women. Further studies are needed to confirm our findings and to evaluate whether F13A1 is causally involved in the pathogenesis of PCOS related metabolic and hormonal disturbances.
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Affiliation(s)
- N Schweighofer
- Medical University of Graz, Division of Endocrinology and Metabolism, Department of Internal Medicine, Auenbruggerplatz 15, 8036 Graz, Austria
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Wehr E, Schweighofer N, Möller R, Giuliani A, Pieber TR, Obermayer-Pietsch B. Association of FTO gene with hyperandrogenemia and metabolic parameters in women with polycystic ovary syndrome. Metabolism 2010; 59:575-80. [PMID: 19913856 DOI: 10.1016/j.metabol.2009.08.023] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 07/27/2009] [Accepted: 08/31/2009] [Indexed: 11/26/2022]
Abstract
Variants in the fat mass and obesity-associated gene (FTO) are associated with obesity and type 2 diabetes mellitus. Women with polycystic ovary syndrome (PCOS) are frequently affected by obesity and impaired glucose tolerance. The aim of this study was to investigate the impact of FTO variants (rs9939609) on metabolic and endocrine parameters in PCOS women. We genotyped the single nucleotide polymorphism rs9939609 (T/A) in 288 PCOS women and performed metabolic and hormonal measurements, oral glucose tolerance test, hirsutism score, and lipometry. The A/T + A/A genotype showed an increased prevalence in overweight/obese PCOS patients (odds ratio [OR] = 1.91, P = .028) and in PCOS women with impaired glucose tolerance (OR = 3.23, P = .009). The A allele was associated with a significant increase in free testosterone (P = .042), weight (P = .024), body mass index (P = .011), 2-hour glucose (P = .047), 1-hour insulin (P = .032), and AUCins (area under the curve insulin) (P = .038). In a logistic regression analysis, the A allele was associated with free testosterone (P = .025; OR = 1.54; 95% confidence interval, 1.06-2.25; B = 0.86). Total body fat (percentage) (P = .016), total fat mass (P = .013), visceral adipose tissue mass (P = .044), and subcutaneous fat mass (P = .011) were significantly increased in PCOS women carrying the A allele. We demonstrated that variants within the FTO gene influence hyperandrogenemia and anthropometric parameters in women with PCOS, indicating an important role of FTO variants not only in obesity and diabetes but also in hyperandrogenism in women with PCOS.
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Affiliation(s)
- Elisabeth Wehr
- Division of Endocrinology and Nuclear Medicine, Department of Internal Medicine, Medical University Graz, A-8036 Graz, Austria.
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Wehr E, Pilz S, Schweighofer N, Giuliani A, Kopera D, Pieber TR, Obermayer-Pietsch B. Association of hypovitaminosis D with metabolic disturbances in polycystic ovary syndrome. Eur J Endocrinol 2009; 161:575-82. [PMID: 19628650 DOI: 10.1530/eje-09-0432] [Citation(s) in RCA: 160] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVES Women with polycystic ovary syndrome (PCOS) frequently suffer from metabolic disturbances, in particular from insulin resistance. Accumulating evidence suggests that vitamin D deficiency may contribute to the development of the metabolic syndrome (MS). Hence, the aim of our study was to investigate the association of 25(OH)D levels and the components of the MS in PCOS women. METHODS 25(OH)D levels were measured by means of ELISA in 206 women affected by PCOS. Metabolic, endocrine, and anthropometric measurements and oral glucose tolerance tests were performed. RESULTS The prevalence of insufficient 25(OH)D levels (<30 ng/ml) was 72.8% in women with PCOS. PCOS women with the MS had lower 25(OH)D levels than PCOS women without these features (17.3 vs 25.8 ng/ml respectively; P<0.05). In multivariate regression analysis including 25(OH)D, season, body mass index (BMI), and age, 25(OH)D and BMI were independent predictors of homeostatic model assessment-insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI; P<0.05 for all). In binary logistic regression analyses, 25(OH)D (OR 0.86, P=0.019) and BMI (OR 1.28, P<0.001) were independent predictors of the MS in PCOS women. We found significantly negative correlations of 25(OH)D levels with BMI, waist circumference, waist-to-hip ratio, systolic and diastolic blood pressure, fasting and stimulated glucose, area under the glucose response curve, fasting insulin, HOMA-IR, HOMA-beta, triglycerides, and quotient total cholesterol/high-density lipoprotein (HDL) and positive correlations of 25(OH)D levels with QUICKI and HDL (P<0.05 for all). CONCLUSION We demonstrate that low 25(OH)D levels are associated with features of the MS in PCOS women. Large intervention trials are warranted to evaluate the effect of vitamin D supplementation on metabolic disturbances in PCOS women.
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Affiliation(s)
- E Wehr
- Divison of Endocrinology and Nuclear Medicine, Department of Internal Medicine, Medical University Graz, Auenbruggerplatz 15, A-8036 Graz, Austria.
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Younggeun Choi, Gordon J, Duckho Kim, Schweighofer N. An Adaptive Automated Robotic Task-Practice System for Rehabilitation of Arm Functions After Stroke. IEEE T ROBOT 2009. [DOI: 10.1109/tro.2009.2019787] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Pilz S, Tomaschitz A, Stepan V, Obermayer-Pietsch B, Fahrleitner-Pammer A, Schweighofer N, Portugaller HR, Sourij H, Dobnig H, Meinitzer A, Pieber TR. Graz Endocrine Causes of Hypertension (GECOH) study: a diagnostic accuracy study of aldosterone to active renin ratio in screening for primary aldosteronism. BMC Endocr Disord 2009; 9:11. [PMID: 19351411 PMCID: PMC2671510 DOI: 10.1186/1472-6823-9-11] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2008] [Accepted: 04/07/2009] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Primary aldosteronism (PA) affects approximately 5 to 10% of all patients with arterial hypertension and is associated with an excess rate of cardiovascular complications that can be significantly reduced by a targeted treatment. There exists a general consensus that the aldosterone to renin ratio should be used as a screening tool but valid data about the accuracy of the aldosterone to renin ratio in screening for PA are sparse. In the Graz endocrine causes of hypertension (GECOH) study we aim to prospectively evaluate diagnostic procedures for PA. METHODS AND DESIGN In this single center, diagnostic accuracy study we will enrol 400 patients that are routinely referred to our tertiary care center for screening for endocrine hypertension. We will determine the aldosterone to active renin ratio (AARR) as a screening test. In addition, all study participants will have a second determination of the AARR and will undergo a saline infusion test (SIT) as a confirmatory test. PA will be diagnosed in patients with at least one AARR of >or= 5.7 ng/dL/ng/L (including an aldosterone concentration of >or= 9 ng/dL) who have an aldosterone level of >or= 10 ng/dL after the saline infusion test. As a primary outcome we will calculate the receiver operating characteristic curve of the AARR in diagnosing PA. Secondary outcomes include the test characteristics of the saline infusion test involving a comparison with 24 hours urine aldosterone levels and the accuracy of the aldosterone to renin activity ratio in diagnosing PA. In addition we will evaluate whether the use of beta-blockers significantly alters the accuracy of the AARR and we will validate our laboratory methods for aldosterone and renin. CONCLUSION Screening for PA with subsequent targeted treatment is of great potential benefit for hypertensive patients. In the GECOH study we will evaluate a standardised procedure for screening and diagnosing of this disease.
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Affiliation(s)
- Stefan Pilz
- Department of Internal Medicine, Division of Endocrinology and Nuclear Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Andreas Tomaschitz
- Department of Internal Medicine, Division of Endocrinology and Nuclear Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Vinzenz Stepan
- Department of Internal Medicine, Division of Endocrinology and Nuclear Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Barbara Obermayer-Pietsch
- Department of Internal Medicine, Division of Endocrinology and Nuclear Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Astrid Fahrleitner-Pammer
- Department of Internal Medicine, Division of Endocrinology and Nuclear Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Natascha Schweighofer
- Department of Internal Medicine, Division of Endocrinology and Nuclear Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Horst R Portugaller
- Department of Radiology, Medical University of Graz, Auenbruggerplatz 9, 8036 Graz, Austria
| | - Harald Sourij
- Department of Internal Medicine, Division of Endocrinology and Nuclear Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Harald Dobnig
- Department of Internal Medicine, Division of Endocrinology and Nuclear Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Andreas Meinitzer
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Thomas R Pieber
- Department of Internal Medicine, Division of Endocrinology and Nuclear Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
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Kovacevic A, Hammer A, Stadelmeyer E, Windischhofer W, Sundl M, Ray A, Schweighofer N, Friedl G, Windhager R, Sattler W, Malle E. Expression of serum amyloid A transcripts in human bone tissues, differentiated osteoblast-like stem cells and human osteosarcoma cell lines. J Cell Biochem 2008; 103:994-1004. [PMID: 17849429 PMCID: PMC4861207 DOI: 10.1002/jcb.21472] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Although the liver is the primary site of cytokine-mediated expression of acute-phase serum amyloid A (SAA) protein, extrahepatic production has also been reported. Besides its role in amyloidosis and lipid homeostasis during the acute-phase, SAA has recently been assumed to contribute to bone and cartilage destruction. However, expression of SAA in human osteogenic tissue has not been studied. Therefore, we first show that SAA1 (coding for the major SAA isoform) but not SAA2 transcripts are expressed in human trabecular and cortical bone fractions and bone marrow. Next, we show expression of (i) IL-1, IL-6, and TNF receptor transcripts; (ii) the human homolog of SAA-activating factor-1 (SAF-1, a transcription factor involved in cytokine-mediated induction of SAA genes); and (iii) SAA1/2 transcripts in non-differentiated and, to a higher extent, in osteoblast-like differentiated human mesenchymal stem cells. Third, we provide evidence that human osteoblast-like cells of tumor origin (MG-63 and SAOS-2) express SAF-1 under basal conditions. SAA1/2 transcripts are expressed under basal conditions (SAOS-2) and cytokine-mediated conditions (MG-63 and SAOS-2). RT-PCR, Western blot analysis, and immunofluorescence technique confirmed cytokine-mediated expression of SAA on RNA and protein level in osteosarcoma cell lines while SAA4, a protein of unknown function, is constitutively expressed in all osteogenic tissues investigated.
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Affiliation(s)
- Alenka Kovacevic
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Center of Molecular Medicine, Graz, Austria
| | - Astrid Hammer
- Institute of Cell Biology, Histology and Embryology, Center of Molecular Medicine, Medical University of Graz, Center of Molecular Medicine, Graz, Austria
| | - Elke Stadelmeyer
- Department of Orthopaedics, Graz University Hospital, Medical University of Graz, Graz, Austria
| | - Werner Windischhofer
- Department of Pediatrics, Research Unit of Osteological Research and Analytical Mass Spectrometry, Medical University of Graz, Graz, Austria
| | - Monika Sundl
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Center of Molecular Medicine, Graz, Austria
| | - Alpana Ray
- Department of Veterinary Pathobiology, University of Missouri-Columbia, Columbia, MO 65211
| | - Natascha Schweighofer
- Division of Endocrinology and Nuclear Medicine, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Gerald Friedl
- Department of Orthopaedics, Graz University Hospital, Medical University of Graz, Graz, Austria
| | - Reinhard Windhager
- Department of Orthopaedics, Graz University Hospital, Medical University of Graz, Graz, Austria
| | - Wolfgang Sattler
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Center of Molecular Medicine, Graz, Austria
| | - Ernst Malle
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Center of Molecular Medicine, Graz, Austria
- Correspondence to: Ernst Malle, Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, A-8010 Graz, Austria.
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Meilinger M, Schweighofer N, Forjanics A, Dobnig H, Fahrleitner-Pammer A, Obermayer-Pietsch B. Autoimmune thyroid disease, genetic predisposition and environment – case-control and family studies. Exp Clin Endocrinol Diabetes 2007. [DOI: 10.1055/s-2007-972423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Schweighofer N, Shishida K, Han CE, Okamoto Y, Tanaka SC, Yamawaki S, Doya K. Humans can adopt optimal discounting strategy under real-time constraints. PLoS Comput Biol 2006; 2:e152. [PMID: 17096592 PMCID: PMC1635539 DOI: 10.1371/journal.pcbi.0020152] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Accepted: 10/04/2006] [Indexed: 11/19/2022] Open
Abstract
Critical to our many daily choices between larger delayed rewards, and smaller more immediate rewards, are the shape and the steepness of the function that discounts rewards with time. Although research in artificial intelligence favors exponential discounting in uncertain environments, studies with humans and animals have consistently shown hyperbolic discounting. We investigated how humans perform in a reward decision task with temporal constraints, in which each choice affects the time remaining for later trials, and in which the delays vary at each trial. We demonstrated that most of our subjects adopted exponential discounting in this experiment. Further, we confirmed analytically that exponential discounting, with a decay rate comparable to that used by our subjects, maximized the total reward gain in our task. Our results suggest that the particular shape and steepness of temporal discounting is determined by the task that the subject is facing, and question the notion of hyperbolic reward discounting as a universal principle.
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Affiliation(s)
- N Schweighofer
- Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, United States of America.
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35
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Schmidt H, Aulchenko YS, Schweighofer N, Schmidt R, Frank S, Kostner GM, Ott E, van Duijn C. Angiotensinogen promoter B-haplotype associated with cerebral small vessel disease enhances basal transcriptional activity. Stroke 2004; 35:2592-7. [PMID: 15472104 DOI: 10.1161/01.str.0000144646.96121.d2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Previously, we described the presence of 5 haplotypes (A to E) at the angiotensinogen (AGT) promoter and reported a significant association between the B-haplotype (nucleotide substitutions -6:G-->A and -20:A-->C compared with the wild-type A-haplotype) and magnetic resonance imaging correlates of cerebral small vessel disease (cSVD). The association was independent of hypertension, suggesting a brain-specific effect of this haplotype. In the current study, we investigated transcriptional activities of the 5 promoter haplotypes in astrocytes, the main source of cerebral AGT, and in hepatocytes, the main source of systemic AGT, as well as determined the evolutionary relatedness of the promoter haplotypes. METHODS Transcriptional activity depending on the haplotypes and the -6:A and -20:C substitutions was measured in transiently transfected A172 and HepG2 cells. We genotyped 5 new single nucleotide polymorphisms (SNPs) at the AGT gene and measured linkage disequilibrium (LD) among SNPs and the promoter haplotypes. An evolution-based haplotype tree was constructed. RESULTS The B-haplotype increased transcriptional activity in both cell types. Its effect was stronger in astrocytes than in hepatocytes (2.4+/-0.09-fold, P<0.001 versus 1.6+/-0.06-fold, P=0.014). Importantly, in astrocytes the combination of the -6:A and the -20:C was mandatory for increased activity, whereas in hepatocytes the -20:C on its own was sufficient. Strong LD between the 5 new SNPs and the promoter haplotypes allowed the reconstruction of 9 haplotypes over the AGT gene. Cladistic analyses suggest that the B-haplotype represents an ancient promoter variant. CONCLUSIONS Combination of the -6:A and -20:C substitutions in the B-haplotype may promote the development of cSVD by enhancing cerebral angiotensinogen expression.
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Affiliation(s)
- Helena Schmidt
- Institute of Medical Molecular Biology and Biochemistry, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria.
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36
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Leber R, Fuchsbichler S, Klobucníková V, Schweighofer N, Pitters E, Wohlfarter K, Lederer M, Landl K, Ruckenstuhl C, Hapala I, Turnowsky F. Molecular mechanism of terbinafine resistance in Saccharomyces cerevisiae. Antimicrob Agents Chemother 2004; 47:3890-900. [PMID: 14638499 PMCID: PMC296195 DOI: 10.1128/aac.47.12.3890-3900.2003] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ten mutants of the yeast Saccharomyces cerevisiae resistant to the antimycotic terbinafine were isolated after chemical or UV mutagenesis. Molecular analysis of these mutants revealed single base pair exchanges in the ERG1 gene coding for squalene epoxidase, the target of terbinafine. The mutants did not show cross-resistance to any of the substrates of various pleiotropic drug resistance efflux pumps tested. The ERG1 mRNA levels in the mutants did not differ from those in the wild-type parent strains. Terbinafine resistance was transmitted with the mutated alleles in gene replacement experiments, proving that single amino acid substitutions in the Erg1 protein were sufficient to confer the resistance phenotype. The amino acid changes caused by the point mutations were clustered in two regions of the Erg1 protein. Seven mutants carried the amino acid substitutions F402L (one mutant), F420L (one mutant), and P430S (five mutants) in the C-terminal part of the protein; and three mutants carried an L251F exchange in the central part of the protein. Interestingly, all exchanges identified involved amino acids which are conserved in the squalene epoxidases of yeasts and mammals. Two mutations that were generated by PCR mutagenesis of the ERG1 gene and that conferred terbinafine resistance mapped in the same regions of the Erg1 protein, with one resulting in an L251F exchange and the other resulting in an F433S exchange. The results strongly indicate that these regions are responsible for the interaction of yeast squalene epoxidase with terbinafine.
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Affiliation(s)
- Regina Leber
- Institute of Molecular Biology, Biochemistry and Microbiology, Karl-Franzens-Universität Graz, Graz, Austria
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Klobucníková V, Kohút P, Leber R, Fuchsbichler S, Schweighofer N, Turnowsky F, Hapala I. Terbinafine resistance in a pleiotropic yeast mutant is caused by a single point mutation in the ERG1 gene. Biochem Biophys Res Commun 2003; 309:666-71. [PMID: 12963042 DOI: 10.1016/j.bbrc.2003.08.051] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A terbinafine-resistant mutant of the yeast Saccharomyces cerevisiae with a complex pleiotropic phenotype (resistance to terbinafine and itraconazole, sensitivity to several antifungal compounds, respiration deficiency, and temperature sensitivity) has been isolated after chemical mutagenesis. Detailed analysis revealed that some of its traits (thermosensitive growth, sensitivity to the polyene antimycotic nystatin and to calcofluor white) are linked to alterations in the cell wall. A single C1288G base change in the ERG1 gene resulting in the substitution of proline by alanine at position 430 in the enzyme squalene epoxidase (Erg1p) was identified as the sole cause of terbinafine resistance. This novel mutation in the ERG1 gene confers only partial resistance of Erg1p to terbinafine, however, even the low level of resistance enables terbinafine-treated mutant cells to maintain adequate ergosterol levels over longer cultivation periods. Lack of interference of squalene accumulation with growth of terbinafine-treated mutant cells indicates that the antimycotic effect of terbinafine in S. cerevisiae may be linked primarily to ergosterol depletion.
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Affiliation(s)
- Vlasta Klobucníková
- Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, Ivanka pri Dunaji, Slovak Republic
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Kuroda S, Schweighofer N, Kawato M. Exploration of signal transduction pathways in cerebellar long-term depression by kinetic simulation. J Neurosci 2001; 21:5693-702. [PMID: 11466441 PMCID: PMC6762656] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
Because multiple molecular signal transduction pathways regulate cerebellar long-term depression (LTD), which is thought to be a possible molecular and cellular basis of cerebellar learning, the systematic relationship between cerebellar LTD and the currently known signal transduction pathways remains obscure. To address this issue, we built a new diagram of signal transduction pathways and developed a computational model of kinetic simulation for the phosphorylation of AMPA receptors, known as a key step for expressing cerebellar LTD. The phosphorylation of AMPA receptors in this model consists of an initial phase and an intermediate phase. We show that the initial phase is mediated by the activation of linear cascades of protein kinase C (PKC), whereas the intermediate phase is mediated by a mitogen-activated protein (MAP) kinase-dependent positive feedback loop pathway that is responsible for the transition from the transient phosphorylation of the AMPA receptors to the stable phosphorylation of the AMPA receptors. These phases are dually regulated by the PKC and protein phosphatase pathways. Both phases also require nitric oxide (NO), although NO per se does not show any ability to induce LTD; this is consistent with a permissive role as reported experimentally (Lev-Ram et al., 1997). Therefore, the kinetic simulation is a powerful tool for understanding and exploring the behaviors of complex signal transduction pathways involved in cerebellar LTD.
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Affiliation(s)
- S Kuroda
- Kawato Dynamic Brain Project, ERATO, Japan Science and Technology, Kyoto 619-0288, Japan.
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Abstract
Marr [J. Physiol. (1969) 202, 437-470] and Albus [Math. Biosci. (1971) 10, 25-61] hypothesized that cerebellar learning is facilitated by a granule cell sparse code, i.e. a neural code in which the fraction of active neurons is low at any one time. In this paper, we re-examine this hypothesis in light of recent experimental and theoretical findings. We argue that cerebellar motor learning is enhanced by a sparse code that simultaneously maximizes information transfer between mossy fibers and granule cells, minimizes redundancies between granule cell discharges, and re-codes the mossy fiber inputs with an adaptive resolution such that inputs corresponding to large errors are finely encoded. We then propose that a set of biologically plausible unsupervised learning rules can produce such a code. To maintain a low mean firing rate compatible with a sparse code, an activity-dependent homeostatic mechanism sets the cells' thresholds. Then, to maximize information transfer, the mossy fiber--granule cell synapses are adjusted by a Hebbian rule. Furthermore, to minimize redundancies between granule cell discharges, the inhibitory Golgi cell--granule cell synapses are tuned by an anti-Hebbian rule. Finally, to allow adaptive resolution, a performance-based neuromodulator-like signal gates these three plastic processes. We integrate these gated learning rules into a simplified model of the cerebellum for arm movement control, and show that unsupervised learning of granule cell sparse codes greatly improves cerebellar adaptive motor control in comparison to a "fixed" Marr--Albus-type model. Until recently, activity-dependent cerebellar plasticity was thought to be largely confined to the granule cell--Purkinje cell synapses. This static view of the cerebellum is, however, quickly being replaced by an extremely dynamic view in which plasticity is omnipresent. The present theoretical study shows how several forms of plasticity in the granular layer of the cerebellum can produce fast, accurate and stable cerebellar learning.
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Affiliation(s)
- N Schweighofer
- ERATO Japan Science and Technology Corporation, 2-2, Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-0288, Japan.
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Abstract
The gaseous second messenger nitric oxide (NO), which readily diffuses in brain tissue, has been implicated in cerebellar long-term depression (LTD), a form of synaptic plasticity thought to be involved in cerebellar learning. Can NO diffusion facilitate cerebellar learning? The inferior olive (IO) cells, which provide the error signals necessary for modifying the granule cell-Purkinje cell (PC) synapses by LTD, fire at ultra-low firing rates in vivo, rarely more than 2-4 spikes within a second. In this paper, we show that NO diffusion can improve the transmission of sporadic IO error signals to PCs within cerebellar cortical functional units, or microzones. To relate NO diffusion to adaptive behavior, we add NO diffusion and a "volumic" LTD learning rule, i.e., a learning rule that depends both on the synaptic activity and on the NO concentration at the synapse, to a cerebellar model for arm movement control. Our results show that biologically plausible diffusion leads to an increase in information transfer of the error signals to the PCs when the IO firing rate is ultra-low. This, in turn, enhances cerebellar learning as shown by improved performance in an arm-reaching task.
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Affiliation(s)
- N Schweighofer
- Exploratory Research for Advanced Technology, Japan Science and Technology, ATR, 2-2, Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-0288, Japan.
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Abstract
Long conduction delays in the nervous system prevent the accurate control of movements by feedback control alone. We present a new, biologically plausible cerebellar model to study how fast arm movements can be executed in spite of these delays. To provide a realistic test-bed of the cerebellar neural model, we embed the cerebellar network in a simulated biological motor system comprising a spinal cord model and a six-muscle two-dimensional arm model. We argue that if the trajectory errors are detected at the spinal cord level, memory traces in the cerebellum can solve the temporal mismatch problem between efferent motor commands and delayed error signals. Moreover, learning is made stable by the inclusion of the cerebello-nucleo-olivary loop in the model. It is shown that the cerebellar network implements a nonlinear predictive regulator by learning part of the inverse dynamics of the plant and spinal circuit. After learning, fast accurate reaching movements can be generated.
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Affiliation(s)
- J Spoelstra
- Department of Computer Sciences, University of Southern California, Los Angeles 90089-2520, USA
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Abstract
As a step in exploring the functions of the inferior olive, we constructed a biophysical model of the olivary neurons to examine their unique electrophysiological properties. The model consists of two compartments to represent the known distribution of ionic currents across the cell membrane, as well as the dendritic location of the gap junctions and synaptic inputs. The somatic compartment includes a low-threshold calcium current (I(Ca_l)), an anomalous inward rectifier current (I(h)), a sodium current (I(Na)), and a delayed rectifier potassium current (I(K_dr)). The dendritic compartment contains a high-threshold calcium current (I(Ca_h)), a calcium-dependent potassium current (I(K_Ca)), and a current flowing into other cells through electrical coupling (I(c)). First, kinetic parameters for these currents were set according to previously reported experimental data. Next, the remaining free parameters were determined to account for both static and spiking properties of single olivary neurons in vitro. We then performed a series of simulated pharmacological experiments using bifurcation analysis and extensive two-parameter searches. Consistent with previous studies, we quantitatively demonstrated the major role of I(Ca_l) in spiking excitability. In addition, I(h) had an important modulatory role in the spike generation and period of oscillations, as previously suggested by Bal and McCormick. Finally, we investigated the role of electrical coupling in two coupled spiking cells. Depending on the coupling strength, the hyperpolarization level, and the I(Ca_l) and I(h) modulation, the coupled cells had four different synchronization modes: the cells could be in-phase, phase-shifted, or anti-phase or could exhibit a complex desynchronized spiking mode. Hence these simulation results support the counterintuitive hypothesis that electrical coupling can desynchronize coupled inferior olive cells.
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Affiliation(s)
- N Schweighofer
- ERATO, Kawato Dynamic Brain Project, Japan Science and Technology Corporation, Kyoto 619-0288 Japan
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Abstract
According to modern views of the cerebellum in motor control, each cerebellar functional unit, or microzone, learns how to execute predictive and coordinative control, based on long-term depression of the granule cell-Purkinje cell synapses. In the present paper, in light of recent experimental and theoretical studies on synaptic elimination and cerebellar motor learning, a model of the formation of cerebellar microzones by climbing fiber synaptic elimination is proposed. It is shown that competition for an activity-dependent supply of neurotrophic factor can reproduce the spatio-temporal characteristics of climbing fiber synaptic elimination. It is further shown that when this elimination is accurate, motor coordination can be acquired in an arm reaching task. In view of the results of the present study, several predictions are proposed.
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Affiliation(s)
- N Schweighofer
- ERATO, Kawato Dynamic Brain Project, Japan Science and Technology Corporation, Kyoto, Japan.
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Abstract
The cerebellum is essential for the control of multijoint movements; when the cerebellum is lesioned, the performance error is more than the summed errors produced by single joints. In the companion paper (Schweighofer et al., 1998), a functional anatomical model for visually guided arm movement was proposed. The model comprised a basic feedforward/feedback controller with realistic transmission delays and was connected to a two-link, six-muscle, planar arm. In the present study, we examined the role of the cerebellum in reaching movements by embedding a novel, detailed cerebellar neural network in this functional control model. We could derive realistic cerebellar inputs and the role of the cerebellum in learning to control the arm was assessed. This cerebellar network learned the part of the inverse dynamics of the arm not provided by the basic feedforward/feedback controller. Despite realistically low inferior olive firing rates and noisy mossy fibre inputs, the model could reduce the error between intended and planned movements. The responses of the different cell groups were comparable to those of biological cell groups. In particular, the modelled Purkinje cells exhibited directional tuning after learning and the parallel fibres, due to their length, provide Purkinje cells with the input required for this coordination task. The inferior olive responses contained two different components; the earlier response, locked to movement onset, was always present and the later response disappeared after learning. These results support the theory that the cerebellum is involved in motor learning.
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Affiliation(s)
- N Schweighofer
- Centre for Neural Engineering, University of Southern California, Los Angeles 90089-2520, USA.
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Abstract
The term "learning rule" in neural network theory usually refers to a rule for the plasticity of a given synapse, whereas metaplasticity involves a "metalearning algorithm" describing higher level control mechanisms for apportioning plasticity across a population of synapses. We propose here that the cerebellar cortex may use metaplasticity, and we demonstrate this by introducing the Cerebellar Adaptive Rate Learning (CARL) algorithm that concentrates learning on those Purkinje cell synapses whose adaptation is most relevant to learning an overall pattern. Our results show that this biologically plausible metalearning algorithm not only improves significantly the learning capability of the cerebellum but is very robust. Finally, we identify several putative neurochemicals that could be involved in a cascade of events leading to adaptive learning rates in Purkinje cell synapses.
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Affiliation(s)
- N Schweighofer
- USC Brain Project, University of Southern California, Los Angeles 90089-2520, USA
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Abstract
This study focuses on the role of the motor cortex, the spinal cord and the cerebellum in the dynamics stage of the control of arm movement. Currently, two classes of models have been proposed for the neural control of movements, namely the virtual trajectory control hypothesis and the acquisition of internal models of the motor apparatus hypothesis. In the present study, we expand the virtual trajectory model to whole arm reaching movements. This expanded model accurately reproduced slow movements, but faster reaching movements deviated significantly from the planned trajectories, indicating that for fast movements, this model was not sufficient. These results led us to propose a new distributed functional model consistent with behavioural, anatomical and neurophysiological data, which takes into account arm muscles, spinal cord, motor cortex and cerebellum and is consistent with the view that the central nervous system acquires a distributed inverse dynamics model of the arm. Previous studies indicated that the cerebellum compensates for the interaction forces that arise during reaching movements. We show here how the cerebellum may increase the accuracy of reaching movements by compensating for the interaction torques by learning a portion of an inverse dynamics model that refines a basic inverse model in the motor cortex and spinal cord.
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Affiliation(s)
- N Schweighofer
- Centre for Neural Engineering, University of Southern California, Los Angeles 90089-2520, USA.
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Abstract
A large, realistic cerebellar neural network has been incorporated into a previously developed saccade model. Using this model, in the present paper, we simulate the complex spatiotemporal behavior of the neuronal subpopulations implicated in adaptive saccadic control. Our simulation results are in good agreement with neurophysiological and behavioral data. Furthermore, we suggest several new experiments to test the validity of our predictions on adaptive saccadic control.
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Affiliation(s)
- N Schweighofer
- Center for Neural Engineering, University of Southern California, Los Angeles 90089-2520, USA.
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Schweighofer N, Arbib MA, Dominey PF. A model of the cerebellum in adaptive control of saccadic gain. I. The model and its biological substrate. Biol Cybern 1996; 75:19-28. [PMID: 8765653 DOI: 10.1007/bf00238736] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We review data showing that the cerebellum is required for adaptation of saccadic gain to repeated presentations of dual-step visual targets and thus, presumably, for providing adaptive corrections for the brainstem saccade generator in response to any error created by the open-loop saccadic system. We model the adaptability of the system in terms of plasticity of synapses from parallel fibers to Purkinje cells in cerebellar cortex, stressing the integration of cerebellar cortex and nuclei in microzones as the units for correction of motor pattern generators. We propose a model of the inferior olive as an error detector, and use a 'window of eligibility' to insure that error signals that elicit a corrective movement are used to adjust the original movement, not the secondary movement. In a companion paper we simulate this large, realistic network of neural-like units to study the complex spatiotemporal behavior of neuronal subpopulations implicated in the control and adaptation of saccades.
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Affiliation(s)
- N Schweighofer
- Center for Neural Engineering, University of Southern California, Los Angeles 90089-2520, USA.
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