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Polachek WS, Baker HP, Dahm JS, Strelzow JA, Hynes KK. Diabetic Kidney Disease Is Associated With Increased Complications Following Operative Management of Ankle Fractures. FOOT & ANKLE ORTHOPAEDICS 2022; 7:24730114221112106. [PMID: 35898793 PMCID: PMC9309779 DOI: 10.1177/24730114221112106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background: Diabetes mellitus and peripheral neuropathy are established risk factors for complications in operatively treated ankle fractures. Generally, the presence of peripheral neuropathy and diabetic nephropathy have been used as independent variables in studies of diabetic ankle fracture cohorts but are typically treated as binary risk factors. Our purpose was to quantify the effects of risk factors on complication rate specific to diabetic patients undergoing ankle fracture fixation. Methods: We identified 617 rotational ankle fractures treated operatively at a single academic medical center from 2010 to 2019, of which 160 were identified as diabetic. Of these, 91 ankle fractures in 90 diabetic patients met criteria for retrospective review of clinical and radiographic data. Criteria included perioperative laboratory studies, including glycated hemoglobin (HbA1c) and estimated glomerular filtration rate (eGFR), as well as follow-up radiographs in the electronic record. We defined complications in this surgical cohort as deep surgical site infection, unplanned return to the operating room, and failure of fixation. Logistic regression was performed and odds ratios (ORs) calculated. Results: The overall complication rate was 28.6% (26/91) in this cohort. Median follow-up was 29 weeks (range: 5-520 weeks). Mean perioperative HbA1c in patients who experienced postoperative complications was 7.6% (range: 5.1%-14.2%) compared with 7.8% (range: 5.6%-13.5%) who did not ( P = .69). Diabetic patients with chronic kidney disease (eGFR <60 mL/min per body surface area) (OR 5.29, P = .006) and peripheral neuropathy (OR 4.61, P = .003) were at significantly higher risk of all complications compared with diabetic patients without these comorbidities. Of note, we did not find an association between perioperative HbA1c or body mass index and complication rate. Conclusion: Patients with diabetes complicated by chronic kidney disease are at significantly higher risk of complications following operative management of ankle fractures. Our study also corroborated previous reports that within this high-risk cohort, the presence of peripheral neuropathy is a significant risk factor for complications. These sequalae of diabetic disease are manifestations of microvascular disease, glycosylation of soft tissues, and impaired metabolic pathways. Identifying these risk factors in diabetic patients allows for patient-specific risk stratification, education, and management decisions of ankle fractures. Level of Evidence: Level III, retrospective cohort study.
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Affiliation(s)
- William S. Polachek
- University of Chicago Department of Orthopaedic Surgery and Rehabilitation Medicine, Chicago, IL, USA
| | - Hayden P. Baker
- University of Chicago Department of Orthopaedic Surgery and Rehabilitation Medicine, Chicago, IL, USA
| | - James S. Dahm
- University of Chicago Department of Orthopaedic Surgery and Rehabilitation Medicine, Chicago, IL, USA
| | - Jason A. Strelzow
- University of Chicago Department of Orthopaedic Surgery and Rehabilitation Medicine, Chicago, IL, USA
| | - Kelly K. Hynes
- University of Chicago Department of Orthopaedic Surgery and Rehabilitation Medicine, Chicago, IL, USA
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2
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Abstract
INTRODUCTION The prevalence of metabolic syndrome has been reported to extremely vary depending on the gender, age, and ethnicity studied. Approximately, 25% of the worldwide adult population is affected by metabolic syndrome, indicating it as a significantly important public health challenge. Likewise, fragility fracture represents an important public health issue too, and the lifetime residual risk of its occurrence has been established in 50% in women and 30% in men over 50 years of age, respectively. Dysmobility syndrome summarizes a cluster of co-existing conditions such as osteoporosis, sarcopenia, obesity. Currently, clinical research focuses essentially on the cardiovascular risks associated with metabolic syndrome. Today, it is conceivable to incorporate all these conditions under a generic "disorder of energy metabolism." EVIDENCE ACQUISITION Animal and human studies suggest metabolic and dysmobility syndromes negatively impact on the risk for fragility fracture, contributing to increase the associated mortality rate. EVIDENCE SYNTHESIS In recent years, strong correlation between type 2 diabetes, a frequent constitutive part of metabolic syndrome and fragility fracture risk has been reported, but the possible molecular mechanisms by which it can occur are still to be defined. CONCLUSIONS Only very few human clinical studies faced these aspects, but they lack adequate endpoints for a good clinical practice in these subjects. Much more still needs to be done before appropriate therapeutic diagnostic pathways will be available for these patients at risk of bone and even generalized fragility. Suggestions for a future overall approach by generating global risk score for these conditions are given.
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Affiliation(s)
- Roberta Cosso
- Section of Bone and Mineral Diseases, San Giuseppe Hospital, Piancavallo, Verbania, Italy
| | - Alberto Falchetti
- Section of Bone and Mineral Diseases, San Giuseppe Hospital, Piancavallo, Verbania, Italy - .,Unit for Bone Metabolism Diseases and Diabetes, Laboratory of Endocrine and Metabolic Research, Istituto Auxologico Italiano IRCCS, Milan, Italy
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3
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Wenzl FA, Ambrosini S, Mohammed SA, Kraler S, Lüscher TF, Costantino S, Paneni F. Inflammation in Metabolic Cardiomyopathy. Front Cardiovasc Med 2021; 8:742178. [PMID: 34671656 PMCID: PMC8520939 DOI: 10.3389/fcvm.2021.742178] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 08/31/2021] [Indexed: 12/24/2022] Open
Abstract
Overlapping pandemics of lifestyle-related diseases pose a substantial threat to cardiovascular health. Apart from coronary artery disease, metabolic disturbances linked to obesity, insulin resistance and diabetes directly compromise myocardial structure and function through independent and shared mechanisms heavily involving inflammatory signals. Accumulating evidence indicates that metabolic dysregulation causes systemic inflammation, which in turn aggravates cardiovascular disease. Indeed, elevated systemic levels of pro-inflammatory cytokines and metabolic substrates induce an inflammatory state in different cardiac cells and lead to subcellular alterations thereby promoting maladaptive myocardial remodeling. At the cellular level, inflammation-induced oxidative stress, mitochondrial dysfunction, impaired calcium handling, and lipotoxicity contribute to cardiomyocyte hypertrophy and dysfunction, extracellular matrix accumulation and microvascular disease. In cardiometabolic patients, myocardial inflammation is maintained by innate immune cell activation mediated by pattern recognition receptors such as Toll-like receptor 4 (TLR4) and downstream activation of the NLRP3 inflammasome and NF-κB-dependent pathways. Chronic low-grade inflammation progressively alters metabolic processes in the heart, leading to a metabolic cardiomyopathy (MC) phenotype and eventually to heart failure with preserved ejection fraction (HFpEF). In accordance with preclinical data, observational studies consistently showed increased inflammatory markers and cardiometabolic features in patients with HFpEF. Future treatment approaches of MC may target inflammatory mediators as they are closely intertwined with cardiac nutrient metabolism. Here, we review current evidence on inflammatory processes involved in the development of MC and provide an overview of nutrient and cytokine-driven pro-inflammatory effects stratified by cell type.
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Affiliation(s)
- Florian A Wenzl
- Center for Molecular Cardiology, University of Zurich, Zurich, Switzerland
| | - Samuele Ambrosini
- Center for Molecular Cardiology, University of Zurich, Zurich, Switzerland
| | - Shafeeq A Mohammed
- Center for Molecular Cardiology, University of Zurich, Zurich, Switzerland
| | - Simon Kraler
- Center for Molecular Cardiology, University of Zurich, Zurich, Switzerland
| | - Thomas F Lüscher
- Center for Molecular Cardiology, University of Zurich, Zurich, Switzerland.,Royal Brompton and Harefield Hospitals and Imperial College, London, United Kingdom
| | - Sarah Costantino
- Center for Molecular Cardiology, University of Zurich, Zurich, Switzerland
| | - Francesco Paneni
- Center for Molecular Cardiology, University of Zurich, Zurich, Switzerland.,University Heart Center, Cardiology, University Hospital Zurich, Zurich, Switzerland.,Department of Research and Education, University Hospital Zurich, Zurich, Switzerland
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4
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Luo B, Zhou X, Tang Q, Yin Y, Feng G, Li S, Chen L. Circadian rhythms affect bone reconstruction by regulating bone energy metabolism. J Transl Med 2021; 19:410. [PMID: 34579752 PMCID: PMC8477514 DOI: 10.1186/s12967-021-03068-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Accepted: 09/02/2021] [Indexed: 01/02/2023] Open
Abstract
Metabolism is one of the most complex cellular biochemical reactions, providing energy and substances for basic activities such as cell growth and proliferation. Early studies have shown that glucose is an important nutrient in osteoblasts. In addition, amino acid metabolism and fat metabolism also play important roles in bone reconstruction. Mammalian circadian clocks regulate the circadian cycles of various physiological functions. In vertebrates, circadian rhythms are mediated by a set of central clock genes: muscle and brain ARNT like-1 (Bmal1), muscle and brain ARNT like-2 (Bmal2), circadian rhythmic motion output cycle stagnates (Clock), cryptochrome 1 (Cry1), cryptochrome2 (Cry2), period 1 (Per1), period 2 (Per2), period 3 (Per3) and neuronal PAS domain protein 2 (Npas2). Negative feedback loops, controlled at both the transcriptional and posttranslational levels, adjust these clock genes in a diurnal manner. According to the results of studies on circadian transcriptomic studies in several tissues, most rhythmic genes are expressed in a tissue-specific manner and are affected by tissue-specific circadian rhythms. The circadian rhythm regulates several activities, including energy metabolism, feeding time, sleeping, and endocrine and immune functions. It has been reported that the circadian rhythms of mammals are closely related to bone metabolism. In this review, we discuss the regulation of the circadian rhythm/circadian clock gene in osteoblasts/osteoclasts and the energy metabolism of bone, and the relationship between circadian rhythm, bone remodeling, and energy metabolism. We also discuss the therapeutic potential of regulating circadian rhythms or changing energy metabolism on bone development/bone regeneration.
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Affiliation(s)
- Beibei Luo
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.,School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China
| | - Xin Zhou
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.,School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China
| | - Qingming Tang
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.,School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China
| | - Ying Yin
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.,School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China
| | - Guangxia Feng
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.,School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China
| | - Shue Li
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China. .,School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China. .,Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China.
| | - Lili Chen
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China. .,School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China. .,Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China.
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Altered Secretome of Diabetic Monocytes Could Negatively Influence Fracture Healing-An In Vitro Study. Int J Mol Sci 2021; 22:ijms22179212. [PMID: 34502120 PMCID: PMC8430926 DOI: 10.3390/ijms22179212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/23/2021] [Accepted: 08/23/2021] [Indexed: 12/12/2022] Open
Abstract
Diabetes mellitus is a main risk factor for delayed fracture healing and fracture non-unions. Successful fracture healing requires stimuli from different immune cells, known to be affected in diabetics. Especially, application of mononuclear cells has been proposed to promote wound and fracture healing. Thus, aim was to investigate the effect of pre-/diabetic conditions on mononuclear cell functions essential to promote osteoprogenitor cell function. We here show that pre-/diabetic conditions suppress the expression of chemokines, e.g., CCL2 and CCL8 in osteoprogenitor cells. The associated MCP-1 and MCP-2 were significantly reduced in serum of diabetics. Both MCPs chemoattract mononuclear THP-1 cells. Migration of these cells is suppressed under hyperglycemic conditions, proposing that less mononuclear cells invade the site of fracture in diabetics. Further, we show that the composition of cytokines secreted by mononuclear cells strongly differ between diabetics and controls. Similar is seen in THP-1 cells cultured under hyperinsulinemia or hyperglycemia. The altered secretome reduces the positive effect of the THP-1 cell conditioned medium on migration of osteoprogenitor cells. In summary, our data support that factors secreted by mononuclear cells may support fracture healing by promoting migration of osteoprogenitor cells but suggest that this effect might be reduced in diabetics.
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6
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Häussling V, Aspera-Werz RH, Rinderknecht H, Springer F, Arnscheidt C, Menger MM, Histing T, Nussler AK, Ehnert S. 3D Environment Is Required In Vitro to Demonstrate Altered Bone Metabolism Characteristic for Type 2 Diabetics. Int J Mol Sci 2021; 22:ijms22062925. [PMID: 33805833 PMCID: PMC8002142 DOI: 10.3390/ijms22062925] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/09/2021] [Accepted: 03/10/2021] [Indexed: 12/19/2022] Open
Abstract
A large British study, with almost 3000 patients, identified diabetes as main risk factor for delayed and nonunion fracture healing, the treatment of which causes large costs for the health system. In the past years, much progress has been made to treat common complications in diabetics. However, there is still a lack of advanced strategies to treat diabetic bone diseases. To develop such therapeutic strategies, mechanisms leading to massive bone alterations in diabetics have to be well understood. We herein describe an in vitro model displaying bone metabolism frequently observed in diabetics. The model is based on osteoblastic SaOS-2 cells, which in direct coculture, stimulate THP-1 cells to form osteoclasts. While in conventional 2D cocultures formation of mineralized matrix is decreased under pre-/diabetic conditions, formation of mineralized matrix is increased in 3D cocultures. Furthermore, we demonstrate a matrix stability of the 3D carrier that is decreased under pre-/diabetic conditions, resembling the in vivo situation in type 2 diabetics. In summary, our results show that a 3D environment is required in this in vitro model to mimic alterations in bone metabolism characteristic for pre-/diabetes. The ability to measure both osteoblast and osteoclast function, and their effect on mineralization and stability of the 3D carrier offers the possibility to use this model also for other purposes, e.g., drug screenings.
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Affiliation(s)
- Victor Häussling
- Siegfried Weller Research Institute, BG Trauma Center Tübingen, Department of Trauma and Reconstructive Surgery, University of Tübingen, Schnarrenbergstr. 95, D-72076 Tübingen, Germany; (V.H.); (R.H.A.-W.); (H.R.); (C.A.); (M.M.M.); (T.H.); (S.E.)
| | - Romina H. Aspera-Werz
- Siegfried Weller Research Institute, BG Trauma Center Tübingen, Department of Trauma and Reconstructive Surgery, University of Tübingen, Schnarrenbergstr. 95, D-72076 Tübingen, Germany; (V.H.); (R.H.A.-W.); (H.R.); (C.A.); (M.M.M.); (T.H.); (S.E.)
| | - Helen Rinderknecht
- Siegfried Weller Research Institute, BG Trauma Center Tübingen, Department of Trauma and Reconstructive Surgery, University of Tübingen, Schnarrenbergstr. 95, D-72076 Tübingen, Germany; (V.H.); (R.H.A.-W.); (H.R.); (C.A.); (M.M.M.); (T.H.); (S.E.)
| | - Fabian Springer
- Department of Diagnostic and Interventional Radiology, University of Tübingen, Hoppe-Seyler-Str. 3, D-72076 Tübingen, Germany;
- Radiology Department, BG Trauma Center Tübingen, Schnarrenbergstr. 95, D-72076 Tübingen, Germany
| | - Christian Arnscheidt
- Siegfried Weller Research Institute, BG Trauma Center Tübingen, Department of Trauma and Reconstructive Surgery, University of Tübingen, Schnarrenbergstr. 95, D-72076 Tübingen, Germany; (V.H.); (R.H.A.-W.); (H.R.); (C.A.); (M.M.M.); (T.H.); (S.E.)
| | - Maximilian M. Menger
- Siegfried Weller Research Institute, BG Trauma Center Tübingen, Department of Trauma and Reconstructive Surgery, University of Tübingen, Schnarrenbergstr. 95, D-72076 Tübingen, Germany; (V.H.); (R.H.A.-W.); (H.R.); (C.A.); (M.M.M.); (T.H.); (S.E.)
| | - Tina Histing
- Siegfried Weller Research Institute, BG Trauma Center Tübingen, Department of Trauma and Reconstructive Surgery, University of Tübingen, Schnarrenbergstr. 95, D-72076 Tübingen, Germany; (V.H.); (R.H.A.-W.); (H.R.); (C.A.); (M.M.M.); (T.H.); (S.E.)
| | - Andreas K. Nussler
- Siegfried Weller Research Institute, BG Trauma Center Tübingen, Department of Trauma and Reconstructive Surgery, University of Tübingen, Schnarrenbergstr. 95, D-72076 Tübingen, Germany; (V.H.); (R.H.A.-W.); (H.R.); (C.A.); (M.M.M.); (T.H.); (S.E.)
- Correspondence: ; Tel.: +49-7071-606-1065
| | - Sabrina Ehnert
- Siegfried Weller Research Institute, BG Trauma Center Tübingen, Department of Trauma and Reconstructive Surgery, University of Tübingen, Schnarrenbergstr. 95, D-72076 Tübingen, Germany; (V.H.); (R.H.A.-W.); (H.R.); (C.A.); (M.M.M.); (T.H.); (S.E.)
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7
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Merlotti D, Cosso R, Eller-Vainicher C, Vescini F, Chiodini I, Gennari L, Falchetti A. Energy Metabolism and Ketogenic Diets: What about the Skeletal Health? A Narrative Review and a Prospective Vision for Planning Clinical Trials on this Issue. Int J Mol Sci 2021; 22:ijms22010435. [PMID: 33406758 PMCID: PMC7796307 DOI: 10.3390/ijms22010435] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/27/2020] [Accepted: 12/30/2020] [Indexed: 12/15/2022] Open
Abstract
The existence of a common mesenchymal cell progenitor shared by bone, skeletal muscle, and adipocytes cell progenitors, makes the role of the skeleton in energy metabolism no longer surprising. Thus, bone fragility could also be seen as a consequence of a “poor” quality in nutrition. Ketogenic diet was originally proven to be effective in epilepsy, and long-term follow-up studies on epileptic children undergoing a ketogenic diet reported an increased incidence of bone fractures and decreased bone mineral density. However, the causes of such negative impacts on bone health have to be better defined. In these subjects, the concomitant use of antiepileptic drugs and the reduced mobilization may partly explain the negative effects on bone health, but little is known about the effects of diet itself, and/or generic alterations in vitamin D and/or impaired growth factor production. Despite these remarks, clinical studies were adequately designed to investigate bone health are scarce and bone health related aspects are not included among the various metabolic pathologies positively influenced by ketogenic diets. Here, we provide not only a narrative review on this issue, but also practical advice to design and implement clinical studies on ketogenic nutritional regimens and bone health outcomes. Perspectives on ketogenic regimens, microbiota, microRNAs, and bone health are also included.
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Affiliation(s)
- Daniela Merlotti
- Department of Medicine, Surgery and Neurosciences, University of Siena, 53100 Siena, Italy; (D.M.); (L.G.)
| | - Roberta Cosso
- Istituto Auxologico Italiano “Scientific Institute for Hospitalisation and Care”, 20100 Milano, Italy; (R.C.); (I.C.)
| | - Cristina Eller-Vainicher
- Unit of Endocrinology, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico Milano, 20122 Milano, Italy;
| | - Fabio Vescini
- Endocrinology and Metabolism Unit, University-Hospital S. Maria della Misericordia of Udine, 33100 Udine, Italy;
| | - Iacopo Chiodini
- Istituto Auxologico Italiano “Scientific Institute for Hospitalisation and Care”, 20100 Milano, Italy; (R.C.); (I.C.)
- Department of Medical Biotechnology and Translational Medicine, University of Milan, 20122 Milano, Italy
| | - Luigi Gennari
- Department of Medicine, Surgery and Neurosciences, University of Siena, 53100 Siena, Italy; (D.M.); (L.G.)
| | - Alberto Falchetti
- Istituto Auxologico Italiano “Scientific Institute for Hospitalisation and Care”, 20100 Milano, Italy; (R.C.); (I.C.)
- Correspondence:
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Use of in vitro bone models to screen for altered bone metabolism, osteopathies, and fracture healing: challenges of complex models. Arch Toxicol 2020; 94:3937-3958. [PMID: 32910238 PMCID: PMC7655582 DOI: 10.1007/s00204-020-02906-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 09/03/2020] [Indexed: 02/06/2023]
Abstract
Approx. every third hospitalized patient in Europe suffers from musculoskeletal injuries or diseases. Up to 20% of these patients need costly surgical revisions after delayed or impaired fracture healing. Reasons for this are the severity of the trauma, individual factors, e.g, the patients’ age, individual lifestyle, chronic diseases, medication, and, over 70 diseases that negatively affect the bone quality. To investigate the various disease constellations and/or develop new treatment strategies, many in vivo, ex vivo, and in vitro models can be applied. Analyzing these various models more closely, it is obvious that many of them have limits and/or restrictions. Undoubtedly, in vivo models most completely represent the biological situation. Besides possible species-specific differences, ethical concerns may question the use of in vivo models especially for large screening approaches. Challenging whether ex vivo or in vitro bone models can be used as an adequate replacement for such screenings, we here summarize the advantages and challenges of frequently used ex vivo and in vitro bone models to study disturbed bone metabolism and fracture healing. Using own examples, we discuss the common challenge of cell-specific normalization of data obtained from more complex in vitro models as one example of the analytical limits which lower the full potential of these complex model systems.
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Li Y, Shrestha A, Zhang H, Li L, Li D, Fu T, Song J, Ji P, Huang Y, Chen T. Impact of diabetes mellitus simulations on bone cell behavior through in vitro models. J Bone Miner Metab 2020; 38:607-619. [PMID: 32415376 DOI: 10.1007/s00774-020-01101-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 03/23/2020] [Indexed: 12/16/2022]
Abstract
Diabetes mellitus (DM) is related to impaired bone healing and an increased risk of bone fractures. While it is recognized that osteogenic differentiation and the function of osteoblasts are suppressed in DM, the influence of DM on osteoclasts is still unclear. Hyperglycemia and inflammatory environment are the hallmark of DM that causes dysregulation of various pro-inflammatory cytokines and alternated gene expression in periodontal ligament cells, osteoblasts, osteocytes, osteoclasts, and osteoclast precursors. A methodological review on conceptual and practical implications of in vitro study models is used for DM simulation on bone cells. Several major databases were screened to find literature related to the study objective. Published literature within last 20 years that used in vitro DM-simulated models to study how DM affects the cellular behavior of bone cells were selected for this review. Studies utilizing high glucose and serum acquired from diabetic animals are the mainly used methods to simulate the diabetic condition. The combination with various simulating factors such as lipopolysaccharide (LPS), hydrogen peroxide (H2O2), and advanced glycation end products (AGEs) have been reported in diabetic situations in vitro, as well. Through screening procedure, it was evident DM-simulated conditions exerted negative impact on bone-related cells. However, inconsistent results were found among different reported studies, which could be due to variation in culture conditions, concentrations of the stimulating factors and cell lineage, etc. This manuscript has concisely reviewed currently existing DM-simulated in vitro models and provides valuable insights of detailed components in simulating DM conditions in vitro. Studies using DM-simulated microenvironment revealed that in vitro simulation negatively impacted periodontal ligament cells, osteoblasts, osteocytes, osteoclasts, and osteoclast precursors. Contrarily, studies also indicated beneficial influence on bone-related cells when such conditions are reversed.
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Affiliation(s)
- Yihan Li
- Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, 426#Songshibei Road, Yubei District, Chongqing, 401147, P.R. China
| | - Annie Shrestha
- Faculty of Dentistry, University of Toronto, Toronto, ON, M5G 1G6, Canada
| | - Hongmei Zhang
- Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, 426#Songshibei Road, Yubei District, Chongqing, 401147, P.R. China
| | - Lingjie Li
- Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, 426#Songshibei Road, Yubei District, Chongqing, 401147, P.R. China
| | - Dize Li
- Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, 426#Songshibei Road, Yubei District, Chongqing, 401147, P.R. China
| | - Tiwei Fu
- Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, 426#Songshibei Road, Yubei District, Chongqing, 401147, P.R. China
| | - Jinlin Song
- Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, 426#Songshibei Road, Yubei District, Chongqing, 401147, P.R. China
| | - Ping Ji
- Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, 426#Songshibei Road, Yubei District, Chongqing, 401147, P.R. China
| | - Yuanding Huang
- Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, 426#Songshibei Road, Yubei District, Chongqing, 401147, P.R. China.
| | - Tao Chen
- Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, 426#Songshibei Road, Yubei District, Chongqing, 401147, P.R. China.
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10
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Skubis-Sikora A, Sikora B, Witkowska A, Mazurek U, Gola J. Osteogenesis of adipose-derived stem cells from patients with glucose metabolism disorders. Mol Med 2020; 26:67. [PMID: 32615920 PMCID: PMC7331176 DOI: 10.1186/s10020-020-00192-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 06/19/2020] [Indexed: 12/13/2022] Open
Abstract
Background Adipose derived stem cells (ADSCs) are clinically widely used somatic stem cells obtained from white adipose tissue. They are characterized by ability to differentiate e.g. into osteoblasts and might successfully regenerate bone tissue in fracture repair. However, the main problem of somatic stem cells is a documented influence of various diseases, drugs or age which can inhibit cells activity. Therefore, in the present study, we investigated the influence of insulin resistance (IR) and type 2 diabetes (T2D) on the proliferation and differentiation potential of ADSCs. Methods The fat from subcutaneous abdominal adipose tissue was acquired by lipoaspiration from 23 voluntary participants, divided into three groups: with diabetes type 2, with insulin resistance and control healthy donors. The proliferative potential was analyzed by cell cytotoxicity assays and by mRNA expression of genes connected with proliferation. Flow cytometry was done for identifying proteins characteristic for mesenchymal stem cells and an analysis of osteogenic differentiation potential based on the assessment of osteogenic markers by real time RT-qPCR, and the evaluation of calcium deposition were also performed. Results The results showed that diabetes type 2 lowered the activity of ADSCs in proliferation assays and changed their phenotypical characteristics. Interestingly, we observed differences in the proliferation potential of ADSCs in patients with insulin resistance, which is often the first phase of diabetes, compared to the control. It might suggest that insulin resistance, early-stage T2D, alters the activity of cells. Moreover, expression of osteogenesis markers was higher in cells from T2D patients than in cells from patients with IR and control. Conclusion We conclude that type 2 diabetes changes the activity of stem cells, and insulin resistance influences on the proliferation of ADSCs.
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Affiliation(s)
- Aleksandra Skubis-Sikora
- Department of Cytophysiology, Chair of Histology and Embryology, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, ul. Medyków 18, C2/108, 40-752, Katowice, Poland
| | - Bartosz Sikora
- Department of Cytophysiology, Chair of Histology and Embryology, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, ul. Medyków 18, C2/108, 40-752, Katowice, Poland.
| | | | - Urszula Mazurek
- Józef Tyszkiewicz Higher School in Bielsko-Biała, ul, Nadbrzeżna 12, 43-300, Bielsko-Biała, Poland
| | - Joanna Gola
- Department of Molecular Biology, Chair of Molecular Biology, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia in Katowice, Katowice, Poland
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11
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Russo V, Chen R, Armamento-Villareal R. Hypogonadism, Type-2 Diabetes Mellitus, and Bone Health: A Narrative Review. Front Endocrinol (Lausanne) 2020; 11:607240. [PMID: 33537005 PMCID: PMC7848021 DOI: 10.3389/fendo.2020.607240] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 11/30/2020] [Indexed: 12/26/2022] Open
Abstract
One of the complications from chronic hyperglycemia and insulin resistance due to type 2 diabetes mellitus (T2DM) on the hypothalamic-pituitary-gonadal axis in men is the high prevalence of hypogonadotropic hypogonadism (HH). Both T2DM and hypogonadism are associated with impaired bone health and increased fracture risk but whether the combination results in even worse bone disease than either one alone is not well-studied. It is possible that having both conditions predisposes men to an even greater risk for fracture than either one alone. Given the common occurrence of HH or hypogonadism in general in T2DM, a significant number of men could be at risk. To date, there is very little information on the bone health men with both hypogonadism and T2DM. Insulin resistance, which is the primary defect in T2DM, is associated with low testosterone (T) levels in men and may play a role in the bidirectional relationship between these two conditions, which together may portend a worse outcome for bone. The present manuscript aims to review the available evidences on the effect of the combination of hypogonadism and T2DM on bone health and metabolic profile, highlights the possible metabolic role of the skeleton, and examines the pathways involved in the interplay between bone, insulin resistance, and gonadal steroids.
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Affiliation(s)
- Vittoria Russo
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, United States
- Department of Medicine, Michael E. DeBakey VA Medical Center, Houston, TX, United States
| | - Rui Chen
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, United States
- Department of Medicine, Michael E. DeBakey VA Medical Center, Houston, TX, United States
| | - Reina Armamento-Villareal
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, United States
- Department of Medicine, Michael E. DeBakey VA Medical Center, Houston, TX, United States
- *Correspondence: Reina Armamento-Villareal,
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12
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Eller-Vainicher C, Cairoli E, Grassi G, Grassi F, Catalano A, Merlotti D, Falchetti A, Gaudio A, Chiodini I, Gennari L. Pathophysiology and Management of Type 2 Diabetes Mellitus Bone Fragility. J Diabetes Res 2020; 2020:7608964. [PMID: 32566682 PMCID: PMC7262667 DOI: 10.1155/2020/7608964] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 04/29/2020] [Accepted: 05/04/2020] [Indexed: 12/14/2022] Open
Abstract
Individuals with type 2 diabetes mellitus (T2DM) have an increased risk of bone fragility fractures compared to nondiabetic subjects. This increased fracture risk may occur despite normal or even increased values of bone mineral density (BMD), and poor bone quality is suggested to contribute to skeletal fragility in this population. These concepts explain why the only evaluation of BMD could not be considered an adequate tool for evaluating the risk of fracture in the individual T2DM patient. Unfortunately, nowadays, the bone quality could not be reliably evaluated in the routine clinical practice. On the other hand, getting further insight on the pathogenesis of T2DM-related bone fragility could consent to ameliorate both the detection of the patients at risk for fracture and their appropriate treatment. The pathophysiological mechanisms underlying the increased risk of fragility fractures in a T2DM population are complex. Indeed, in T2DM, bone health is negatively affected by several factors, such as inflammatory cytokines, muscle-derived hormones, incretins, hydrogen sulfide (H2S) production and cortisol secretion, peripheral activation, and sensitivity. All these factors may alter bone formation and resorption, collagen formation, and bone marrow adiposity, ultimately leading to reduced bone strength. Additional factors such as hypoglycemia and the consequent increased propensity for falls and the direct effects on bone and mineral metabolism of certain antidiabetic medications may contribute to the increased fracture risk in this population. The purpose of this review is to summarize the literature evidence that faces the pathophysiological mechanisms underlying bone fragility in T2DM patients.
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Affiliation(s)
- C. Eller-Vainicher
- Unit of Endocrinology, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Milan, Italy
| | - E. Cairoli
- Istituto Auxologico Italiano, IRCCS, Unit for Bone Metabolism Diseases and Diabetes & Lab of Endocrine and Metabolic Research, Italy
- Dept. of Clinical Sciences & Community Health, University of Milan, Milan, Italy
| | - G. Grassi
- Unit of Endocrinology, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Milan, Italy
- Dept. of Clinical Sciences & Community Health, University of Milan, Milan, Italy
| | - F. Grassi
- Ramses Lab, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - A. Catalano
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - D. Merlotti
- Department of Medicine, Surgery and Neurosciences, University of Siena, Italy
| | - A. Falchetti
- Istituto Auxologico Italiano, IRCCS, Unit for Bone Metabolism Diseases and Diabetes & Lab of Endocrine and Metabolic Research, Italy
| | - A. Gaudio
- Department of Clinical and Experimental Medicine, University of Catania, University Hospital ‘G. Rodolico', Catania, Italy
| | - I. Chiodini
- Istituto Auxologico Italiano, IRCCS, Unit for Bone Metabolism Diseases and Diabetes & Lab of Endocrine and Metabolic Research, Italy
- Dept. of Clinical Sciences & Community Health, University of Milan, Milan, Italy
| | - L. Gennari
- Department of Medicine, Surgery and Neurosciences, University of Siena, Italy
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Cigarette Smoke Induces the Risk of Metabolic Bone Diseases: Transforming Growth Factor Beta Signaling Impairment via Dysfunctional Primary Cilia Affects Migration, Proliferation, and Differentiation of Human Mesenchymal Stem Cells. Int J Mol Sci 2019; 20:ijms20122915. [PMID: 31207955 PMCID: PMC6628373 DOI: 10.3390/ijms20122915] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 05/27/2019] [Accepted: 06/12/2019] [Indexed: 12/18/2022] Open
Abstract
It is well established that smoking has detrimental effects on bone integrity and is a preventable risk factor for metabolic bone disorders. Following orthopedic surgeries, smokers frequently show delayed fracture healing associated with many complications, which results in prolonged hospital stays. One crucial factor responsible for fracture repair is the recruitment and differentiation of mesenchymal stem cells (MSCs) at early stages, a mechanism mediated by transforming growth factor β (TGF-β). Although it is known that smokers frequently have decreased TGF-β levels, little is known about the actual signaling occurring in these patients. We investigated the effect of cigarette smoke on TGF-β signaling in MSCs to evaluate which step in the pathway is affected by cigarette smoke extract (CSE). Single-cell-derived human mesenchymal stem cell line (SCP-1 cells) were treated with CSE concentrations associated with smoking up to 20 cigarettes a day. TGF-β signaling was analyzed using an adenovirus-based reporter assay system. Primary cilia structure and downstream TGF-β signaling modulators (Smad2, Smad3, and Smad4) were analyzed by Western blot and immunofluorescence staining. CSE exposure significantly reduced TGF-β signaling. Intriguingly, we observed that protein levels of phospho-Smad2/3 (active forms) as well as nuclear translocation of the phospho-Smad3/4 complex decreased after CSE exposure, phenomena that affected signal propagation. CSE exposure reduced the activation of TGF-β modulators under constitutive activation of TGF-β receptor type I (ALK5), evidencing that CSE affects signaling downstream of the ALK5 receptor but not the binding of the cytokine to the receptor itself. CSE-mediated TGF-β signaling impaired MSC migration, proliferation, and differentiation and ultimately affected endochondral ossification. Thus, we conclude that CSE-mediated disruption of TGF-β signaling in MSCs is partially responsible for delayed fracture healing in smokers.
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14
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Picke AK, Campbell G, Napoli N, Hofbauer LC, Rauner M. Update on the impact of type 2 diabetes mellitus on bone metabolism and material properties. Endocr Connect 2019; 8:R55-R70. [PMID: 30772871 PMCID: PMC6391903 DOI: 10.1530/ec-18-0456] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 01/24/2019] [Indexed: 11/23/2022]
Abstract
The prevalence of type 2 diabetes mellitus (T2DM) is increasing worldwide, especially as a result of our aging society, high caloric intake and sedentary lifestyle. Besides the well-known complications of T2DM on the cardiovascular system, the eyes, kidneys and nerves, bone strength is also impaired in diabetic patients. Patients with T2DM have a 40-70% increased risk for fractures, despite having a normal to increased bone mineral density, suggesting that other factors besides bone quantity must account for increased bone fragility. This review summarizes the current knowledge on the complex effects of T2DM on bone including effects on bone cells, bone material properties and other endocrine systems that subsequently affect bone, discusses the effects of T2DM medications on bone and concludes with a model identifying factors that may contribute to poor bone quality and increased bone fragility in T2DM.
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Affiliation(s)
- Ann-Kristin Picke
- Institute of Comparative Molecular Endocrinology, Ulm University, Ulm, Germany
| | - Graeme Campbell
- Institute of Biomechanics, TUHH Hamburg University of Technology, Hamburg, Germany
| | - Nicola Napoli
- Diabetes and Bone Network, Department Endocrinology and Diabetes, University Campus Bio-Medico of Rome, Rome, Italy
- Division of Bone and Mineral Diseases, Washington University in St Louis, St Louis, Missouri, USA
| | - Lorenz C Hofbauer
- Department of Medicine III & Center for Healthy Aging, Technische Universität Dresden, Dresden, Germany
| | - Martina Rauner
- Department of Medicine III & Center for Healthy Aging, Technische Universität Dresden, Dresden, Germany
- Correspondence should be addressed to M Rauner:
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15
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Rogal J, Zbinden A, Schenke-Layland K, Loskill P. Stem-cell based organ-on-a-chip models for diabetes research. Adv Drug Deliv Rev 2019; 140:101-128. [PMID: 30359630 DOI: 10.1016/j.addr.2018.10.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 09/10/2018] [Accepted: 10/19/2018] [Indexed: 12/22/2022]
Abstract
Diabetes mellitus (DM) ranks among the severest global health concerns of the 21st century. It encompasses a group of chronic disorders characterized by a dysregulated glucose metabolism, which arises as a consequence of progressive autoimmune destruction of pancreatic beta-cells (type 1 DM), or as a result of beta-cell dysfunction combined with systemic insulin resistance (type 2 DM). Human cohort studies have provided evidence of genetic and environmental contributions to DM; yet, these studies are mostly restricted to investigating statistical correlations between DM and certain risk factors. Mechanistic studies, on the other hand, aimed at re-creating the clinical picture of human DM in animal models. A translation to human biology is, however, often inadequate owing to significant differences between animal and human physiology, including the species-specific glucose regulation. Thus, there is an urgent need for the development of advanced human in vitro models with the potential to identify novel treatment options for DM. This review provides an overview of the technological advances in research on DM-relevant stem cells and their integration into microphysiological environments as provided by the organ-on-a-chip technology.
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Affiliation(s)
- Julia Rogal
- Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University, Silcherstrasse 7/1, 72076 Tübingen, Germany; Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Nobelstrasse 12, 70569 Stuttgart, Germany
| | - Aline Zbinden
- Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University, Silcherstrasse 7/1, 72076 Tübingen, Germany
| | - Katja Schenke-Layland
- Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University, Silcherstrasse 7/1, 72076 Tübingen, Germany; The Natural and Medical Sciences Institute (NMI) at the University of Tübingen, Markwiesenstr. 55, 72770 Reutlingen, Germany; Department of Medicine/Cardiology, Cardiovascular Research Laboratories, David Geffen School of Medicine at UCLA, 675 Charles E. Young Drive South, MRL 3645, Los Angeles, CA, USA.
| | - Peter Loskill
- Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University, Silcherstrasse 7/1, 72076 Tübingen, Germany; Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Nobelstrasse 12, 70569 Stuttgart, Germany
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16
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Usala RL, Fernandez SJ, Mete M, Shara NM, Verbalis JG. Hyponatremia Is Associated With Increased Osteoporosis and Bone Fractures in Patients With Diabetes With Matched Glycemic Control. J Endocr Soc 2019; 3:411-426. [PMID: 30746503 PMCID: PMC6364625 DOI: 10.1210/js.2018-00320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 12/28/2018] [Indexed: 12/18/2022] Open
Abstract
Context Patients with diabetes mellitus are at increased risk for bone fragility fracture secondary to multiple mechanisms. Hyperglycemia can induce true dilutional hyponatremia. Hyponatremia is associated with gait instability, osteoporosis, and increased falls and bone fractures, and studies suggest that compromised bone quality with hyponatremia may be independent of plasma osmolality. We performed a case-control study of patients with diabetes mellitus matched by median glycated hemoglobin (HbA1c) to assess whether hyponatremia was associated with increased risk of osteoporosis and/or fragility fracture. Design Osteoporosis (n = 823) and fragility fracture (n = 840) cases from the MedStar Health database were matched on age of first HbA1c ≥6.5%, sex, race, median HbA1c over an interval from first HbA1c ≥6.5% to the end of the encounter window, diabetic encounter window length, and type 1 vs type 2 diabetes mellitus with controls without osteoporosis (n = 823) and without fragility fractures (n = 840), respectively. Clinical variables, including coefficient of glucose variation and hyponatremia (defined as serum [Na+] <135 mmol/dL within 30 days of the end of the diabetic window), were included in a multivariate analysis. Results Multivariate conditional logistic regression models demonstrated that hyponatremia within 30 days of the outcome measure was independently associated with osteoporosis and fragility fractures (osteoporosis OR 3.09; 95% CI, 1.37 to 6.98; fracture OR, 6.41; 95% CI, 2.44 to 16.82). Conclusions Our analyses support the hypothesis that hyponatremia is an additional risk factor for osteoporosis and fragility fracture among patients with diabetes mellitus.
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Affiliation(s)
- Rachel L Usala
- Graduate Medical Education, Department of Medicine, MedStar Georgetown University Hospital, Washington, District of Columbia
| | - Stephen J Fernandez
- Department of Biostatistics and Bioinformatics, MedStar Health Research Institute, Washington, District of Columbia
| | - Mihriye Mete
- Department of Biostatistics and Bioinformatics, MedStar Health Research Institute, Washington, District of Columbia
| | - Nawar M Shara
- Department of Biostatistics and Bioinformatics, MedStar Health Research Institute, Washington, District of Columbia
| | - Joseph G Verbalis
- Division of Endocrinology and Metabolism, Georgetown University Medical Center, Washington, District of Columbia
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17
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Nicotine and Cotinine Inhibit Catalase and Glutathione Reductase Activity Contributing to the Impaired Osteogenesis of SCP-1 Cells Exposed to Cigarette Smoke. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:3172480. [PMID: 30533170 PMCID: PMC6250005 DOI: 10.1155/2018/3172480] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 08/20/2018] [Accepted: 08/29/2018] [Indexed: 01/13/2023]
Abstract
Cigarette smoking has been identified as a major risk factor for osteoporosis decades ago. Several studies have shown a direct relationship between cigarette smoking, decreased bone mineral density, and impaired fracture healing. However, the mechanisms behind impaired fracture healing and cigarette smoking are yet to be elucidated. Migration and osteogenesis of mesenchymal stem/stromal cells (MSCs) into the fracture site play a vital role in the process of fracture healing. In human nicotine, the most pharmacologically active and major addictive component present in tobacco gets rapidly metabolized to the more stable cotinine. This study demonstrates that physiological concentrations of both nicotine and cotinine do not affect the osteogenic differentiation of MSCs. However, cigarette smoke exposure induces oxidative stress by increasing superoxide radicals and reducing intracellular glutathione in MSCs, negatively affecting osteogenic differentiation. Although, not actively producing reactive oxygen species (ROS) nicotine and cotinine inhibit catalase and glutathione reductase activity, contributing to an accumulation of ROS by cigarette smoke exposure. Coincubation with N-acetylcysteine or L-ascorbate improves impaired osteogenesis caused by cigarette smoke exposure by both activation of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling and scavenging of ROS, which thus might represent therapeutic targets to support fracture healing in smokers.
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18
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Zhu S, Ehnert S, Rouß M, Häussling V, Aspera-Werz RH, Chen T, Nussler AK. From the Clinical Problem to the Basic Research-Co-Culture Models of Osteoblasts and Osteoclasts. Int J Mol Sci 2018; 19:ijms19082284. [PMID: 30081523 PMCID: PMC6121694 DOI: 10.3390/ijms19082284] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 07/26/2018] [Accepted: 07/31/2018] [Indexed: 12/13/2022] Open
Abstract
Bone tissue undergoes constant remodeling and healing when fracture happens, in order to ensure its structural integrity. In order to better understand open biological and clinical questions linked to various bone diseases, bone cell co-culture technology is believed to shed some light into the dark. Osteoblasts/osteocytes and osteoclasts dominate the metabolism of bone by a multitude of connections. Therefore, it is widely accepted that a constant improvement of co-culture models with both cell types cultured on a 3D scaffold, is aimed to mimic an in vivo environment as closely as possible. Although in recent years a considerable knowledge of bone co-culture models has been accumulated, there are still many open questions. We here try to summarize the actual knowledge and address open questions.
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Affiliation(s)
- Sheng Zhu
- Department of Trauma and Reconstructive Surgery, Siegfried Weller Institute for Trauma Research, Eberhard Karls University Tuebingen, BG Trauma Center Tuebingen, 72076 Tuebingen, Germany.
| | - Sabrina Ehnert
- Department of Trauma and Reconstructive Surgery, Siegfried Weller Institute for Trauma Research, Eberhard Karls University Tuebingen, BG Trauma Center Tuebingen, 72076 Tuebingen, Germany.
| | - Marc Rouß
- Department of Trauma and Reconstructive Surgery, Siegfried Weller Institute for Trauma Research, Eberhard Karls University Tuebingen, BG Trauma Center Tuebingen, 72076 Tuebingen, Germany.
| | - Victor Häussling
- Department of Trauma and Reconstructive Surgery, Siegfried Weller Institute for Trauma Research, Eberhard Karls University Tuebingen, BG Trauma Center Tuebingen, 72076 Tuebingen, Germany.
| | - Romina H Aspera-Werz
- Department of Trauma and Reconstructive Surgery, Siegfried Weller Institute for Trauma Research, Eberhard Karls University Tuebingen, BG Trauma Center Tuebingen, 72076 Tuebingen, Germany.
| | - Tao Chen
- Department of Trauma and Reconstructive Surgery, Siegfried Weller Institute for Trauma Research, Eberhard Karls University Tuebingen, BG Trauma Center Tuebingen, 72076 Tuebingen, Germany.
| | - Andreas K Nussler
- Department of Trauma and Reconstructive Surgery, Siegfried Weller Institute for Trauma Research, Eberhard Karls University Tuebingen, BG Trauma Center Tuebingen, 72076 Tuebingen, Germany.
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Stolarczyk A, Sarzyńska S, Gondek A, Cudnoch-Jędrzejewska A. Influence of diabetes on tissue healing in orthopaedic injuries. Clin Exp Pharmacol Physiol 2018; 45:619-627. [PMID: 29570835 DOI: 10.1111/1440-1681.12939] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 02/15/2018] [Accepted: 03/12/2018] [Indexed: 12/22/2022]
Abstract
Diabetes is a group of metabolic diseases characterized by hyperglycaemia resulting from the defective action or secretion of insulin. Chronic hyperglycaemia can lead to the damage, dysfunction and failure of various organs. In the context of complications of healing and orthopaedic rehabilitation, vascular (microangiopathy) and nerve (neuropathy) disorders deserve particular attention. About 12% of the patients admitted to orthopaedic departments have diabetes. Studies indicate that there is an indisputable link between diabetes and: an increased risk of fractures, the difficult healing of injuries of bones, ligaments and musculotendinous. It appears that one of the main reasons for this is non-enzymatic glycosylation (glycation) of collagen molecules, a phenomenon observed in the elderly and diabetic populations, as it leads to the formation of advanced glycation end products (AGEs). Collagen is one of the major connective tissue components, and is therefore part of ligaments, tendons and bones. AGEs affect the weakening of its structure and biomechanical properties, and thus also affects the weakening of the structure and properties of the above-mentioned tissues. The aim of the study is to undertake an overview of the current knowledge of the impact of diabetes on the risk of some injuries and subsequent healing and rehabilitation of patients following orthopaedic injuries.
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Affiliation(s)
- Artur Stolarczyk
- Department of Clinical Rehabilitation, Second Faculty of Medicine, Medical University of Warsaw, Warsaw, Poland
| | - Sylwia Sarzyńska
- Department of Orthopaedics and Traumatology, Medical University of Warsaw, Warsaw, Poland
| | - Agata Gondek
- Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
| | - Agnieszka Cudnoch-Jędrzejewska
- Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
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20
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Sreekumar V, Aspera-Werz R, Ehnert S, Strobel J, Tendulkar G, Heid D, Schreiner A, Arnscheidt C, Nussler AK. Resveratrol protects primary cilia integrity of human mesenchymal stem cells from cigarette smoke to improve osteogenic differentiation in vitro. Arch Toxicol 2018; 92:1525-1538. [PMID: 29264620 DOI: 10.1007/s00204-017-2149-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 12/14/2017] [Indexed: 12/21/2022]
Abstract
Several studies have explored the negative effects of cigarette smoke on bone healing; however, the complex pathogenesis still remains unclear. One crucial and primary factor determining effective fracture repair is the recruitment and differentiation of mesenchymal stem cells (MSCs) into bone-forming cells. Recently, primary cilia, microtubule-based sensory organelles, have been shown to be critical in lineage commitment and differentiation of MSCs. Our present study indicates that exposure to cigarette smoke extract (CSE 0.1-10%) impaired osteogenic differentiation of human mesenchymal stem cell line (SCP-1) and interestingly, also affected primary cilia distribution and integrity in these cells during the differentiation. Furthermore, significant amounts of free radicals generated by CSE could be causative of primary cilia loss since treatment with 0.01% of hydrogen peroxide, a prime free radical in CSE, destroyed primary cilia in these cells. The debilitated differentiation of CSE-exposed SCP-1 cells also correlated with the significantly reduced expression of transcription factor and target genes of primary cilia-specific hedgehog signalling, a key player in osteogenic differentiation. As a treatment strategy, co-incubation of the CSE-exposed SCP-1 cells with the antioxidant resveratrol (1 µM) had a protective effect as it significantly reduced free radical production, protected the primary cilia and enhanced osteogenic differentiation. The current study shows for the first time that cigarette smoke affects primary cilia in human MSCs during osteogenic differentiation and treatment with resveratrol could reverse the effects and enhance differentiation, thus opening up potential therapeutic alternatives to treat fracture healing in smokers, in particularly, when delayed fracture healing is assumed.
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Affiliation(s)
- Vrinda Sreekumar
- Department of Traumatology, BG Trauma Clinic, Siegfried Weller Institute for Trauma Research, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Romina Aspera-Werz
- Department of Traumatology, BG Trauma Clinic, Siegfried Weller Institute for Trauma Research, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Sabrina Ehnert
- Department of Traumatology, BG Trauma Clinic, Siegfried Weller Institute for Trauma Research, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Julius Strobel
- Department of Traumatology, BG Trauma Clinic, Siegfried Weller Institute for Trauma Research, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Gauri Tendulkar
- Department of Traumatology, BG Trauma Clinic, Siegfried Weller Institute for Trauma Research, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Daniel Heid
- Department of Traumatology, BG Trauma Clinic, Siegfried Weller Institute for Trauma Research, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Anna Schreiner
- Department of Traumatology, BG Trauma Clinic, Siegfried Weller Institute for Trauma Research, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Christian Arnscheidt
- Department of Traumatology, BG Trauma Clinic, Siegfried Weller Institute for Trauma Research, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Andreas K Nussler
- Department of Traumatology, BG Trauma Clinic, Siegfried Weller Institute for Trauma Research, Eberhard Karls Universität Tübingen, Tübingen, Germany.
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Gortler H, Rusyn J, Godbout C, Chahal J, Schemitsch EH, Nauth A. Diabetes and Healing Outcomes in Lower Extremity Fractures: A Systematic Review. Injury 2018; 49:177-183. [PMID: 29162268 DOI: 10.1016/j.injury.2017.11.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 10/30/2017] [Accepted: 11/09/2017] [Indexed: 02/02/2023]
Abstract
OBJECTIVE The purpose of this study was to review the rates of adverse healing outcomes following surgical fixation of lower extremity fractures in diabetic patients and matched controls. MATERIALS AND METHODS Searches of PubMed, MEDLINE, CINAHL and Embase were performed for studies published between the date of database inception and July 6, 2015. Patient characteristics and the incidence of adverse healing outcomes (nonunion, malunion, delayed union, infection and reoperation) were extracted from each study. The occurrence of each fracture healing complication was pooled and analyzed for comparisons between diabetic and non-diabetic patients. An odds ratio with a 95% confidence interval for each healing outcome was calculated between the diabetic and non-diabetic groups. RESULTS Diabetes was found to significantly increase rates of malunion, infection and reoperation in patients with surgically treated lower extremity fractures. In addition, when only peripheral lower extremity fractures (i.e. below the knee) were examined, diabetes significantly increased the rates of nonunion. CONCLUSION Diabetes substantially alters bone metabolism and soft tissue healing, posing a risk of adverse fracture healing and other complications. This systematic review provides evidence that the presence of diabetes significantly increases the risks of infection, malunion, nonunion and re-operation across a wide variety of surgically treated lower extremity fractures. This study provides prognostic information for clinicians and may aid in guiding treatment for this population.
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Affiliation(s)
- Hilary Gortler
- Division of Orthopaedics, Department of Surgery, St. Michael's Hospital, University of Toronto, Canada
| | - Jessyca Rusyn
- Division of Orthopaedics, Department of Surgery, St. Michael's Hospital, University of Toronto, Canada
| | - Charles Godbout
- Division of Orthopaedics, Department of Surgery, St. Michael's Hospital, University of Toronto, Canada
| | - Jas Chahal
- Toronto Western Hospital, University of Toronto Orthopaedic Sports Medicine, Canada
| | - Emil H Schemitsch
- Division of Orthopaedics, Department of Surgery, St. Michael's Hospital, University of Toronto, Canada; Department of Surgery, University of Western Ontario, Canada
| | - Aaron Nauth
- Division of Orthopaedics, Department of Surgery, St. Michael's Hospital, University of Toronto, Canada.
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22
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Sun W, Yao S, Tang J, Liu S, Chen J, Deng D, Zeng C. Integrative analysis of super enhancer SNPs for type 2 diabetes. PLoS One 2018; 13:e0192105. [PMID: 29385209 PMCID: PMC5792005 DOI: 10.1371/journal.pone.0192105] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 01/18/2018] [Indexed: 01/01/2023] Open
Abstract
Clinical studies in type 2 diabetes (T2D) primarily focused on the single nucleotide polymorphisms (SNPs) located in protein-coding regions. Recently, the SNPs located in noncoding regions have also been recognized to play an important role in disease susceptibility. The super enhancer is a cluster of transcriptional enhancers located in noncoding regions. It plays a critical role in cell-type specific gene expression. However, the exact mechanism of the super enhancer SNPs for T2D remains unclear. In this study, we integrated genome-wide association studies (GWASs) and T2D cell/tissue-specific histone modification ChIP-seq data to identify T2D-associated SNPs in super enhancer, followed by comprehensive bioinformatics analyses to further explore the functional importance of these SNPs. We identified several interesting T2D super enhancer SNPs. Interesting, most of them were clustered within the same or neighboring super enhancers. A number of SNPs are involved in chromatin interactive regulation and/or potentially influence the binding affinity of transcription factors. Gene Ontology (GO) analysis showed a significant enrichment in several well-known signaling pathways and regulatory process, e.g. WNT signaling pathway, which plays a key role in T2D metabolism. Our results highlighted the potential functional importance of T2D super enhancer SNPs, which may yield novel insights into the pathogenesis of T2D.
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Affiliation(s)
- Weiping Sun
- Department of Geriatrics, the First People's Hospital of Xiangtan City, Xiangtan, PR, China
| | - Sihong Yao
- Department of Clinical Medicine, Jishou University School of Medicine, Jishou, PR, China
| | - Jielong Tang
- Department of Endocrinology, the Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou, PR, China
| | - Shuai Liu
- Department of Endocrinology, the Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou, PR, China
| | - Juan Chen
- Department of Geriatrics, the First People's Hospital of Xiangtan City, Xiangtan, PR, China
| | - Daqing Deng
- Department of Geriatrics, the First People's Hospital of Xiangtan City, Xiangtan, PR, China
| | - Chunping Zeng
- Department of Endocrinology, the Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou, PR, China
- * E-mail:
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23
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Tang Y, Zheng L, Zhou J, Chen Y, Yang L, Deng F, Hu Y. miR‑203‑3p participates in the suppression of diabetes‑associated osteogenesis in the jaw bone through targeting Smad1. Int J Mol Med 2018; 41:1595-1607. [PMID: 29328402 PMCID: PMC5819914 DOI: 10.3892/ijmm.2018.3373] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 01/04/2018] [Indexed: 12/24/2022] Open
Abstract
Certain microRNAs (miRs) have important roles in the maintenance of bone development and metabolism, and a variety of miRs are known to be deregulated in diabetes. The present study investigated the role of miR-203-3p in the regulation of bone loss by assessing jaw bones of a rat model of type 2 diabetes. The results indicated that miR-203-3p inhibited osteogenesis in the jaws of diabetic rats and in rat bone marrow mesenchymal stem cells cultured in high-glucose medium. A luciferase re porter assay was used to verify the bioinformatics prediction that miR-203-3p targets the 3′-untranslated region of Smad1, which is an important mediator of the bone morphogenetic protein (BMP)/Smad pathway. Overexpression of Smad1 attenuated the miR-203-3p-mediated suppres sion of osteogenic differentiation. It was therefore indicated that the BMP/Smad pathway is attenuated and the transforming growth factor-β/activin pathway is promoted by Smad1 reduction. Taken together, it was indicated that miR-203-3p inhibits osteogenesis in jaw bones of diabetic rats by targeting Smad1 to inhibit the BMP/Smad pathway.
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Affiliation(s)
- Yuying Tang
- Department of Endodontics, The Affiliated Stomatology Hospital, Chongqing Medical University, Chongqing 401147, P.R. China
| | - Leilei Zheng
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, The Affiliated Stomatology Hospital, Chongqing Medical University, Chongqing 401147, P.R. China
| | - Jie Zhou
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, The Affiliated Stomatology Hospital, Chongqing Medical University, Chongqing 401147, P.R. China
| | - Yang Chen
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, The Affiliated Stomatology Hospital, Chongqing Medical University, Chongqing 401147, P.R. China
| | - Lan Yang
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, The Affiliated Stomatology Hospital, Chongqing Medical University, Chongqing 401147, P.R. China
| | - Feng Deng
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, The Affiliated Stomatology Hospital, Chongqing Medical University, Chongqing 401147, P.R. China
| | - Yun Hu
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, The Affiliated Stomatology Hospital, Chongqing Medical University, Chongqing 401147, P.R. China
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24
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Ehnert S, Sreekumar V, Aspera-Werz RH, Sajadian SO, Wintermeyer E, Sandmann GH, Bahrs C, Hengstler JG, Godoy P, Nussler AK. TGF-β 1 impairs mechanosensation of human osteoblasts via HDAC6-mediated shortening and distortion of primary cilia. J Mol Med (Berl) 2017; 95:653-663. [PMID: 28271209 DOI: 10.1007/s00109-017-1526-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 01/29/2017] [Accepted: 02/24/2017] [Indexed: 12/11/2022]
Abstract
Transforming growth factor β (TGF-β) is a critical regulator of bone density owing to its multiple effects on cell growth and differentiation. Recently, we have shown that TGF-β1 effectively blocks bone morphogenetic protein (BMP) induced maturation of osteoblasts by upregulating histone deacetylase (HDAC) activity. The current study aimed at investigating the effect of rhTGF-β1 treatment on the expression of specific HDACs and their cellular effects, e.g., microtubule structures (primary cilia) and mechanosensation. Exposure to TGF-β1 most significantly induced expression of HDAC6 both on gene and protein level. Being most abundant in the cytoplasm HDAC6 effectively deacetylates microtubule structures. Thus, TGF-β1-induced expression of HDAC6 led to deformation and shortening of primary cilia as well as to reduced numbers of ciliated cells. Primary cilia are described to sense mechanical stimuli. Thus, fluid flow was applied to the cells, which stimulated osteoblast function (AP activity and matrix mineralization). Compromised primary cilia in TGF-β1-treated cells were associated with reduced osteogenic function, despite exposure to fluid flow conditions. Chemical inhibition of HDAC6 with Tubacin restored primary cilium structure and length. These cells showed improved osteogenic function especially under fluid flow conditions. Summarizing our results, TGF-β1 impairs human osteoblast maturation partially via HDAC6-mediated distortion and/or shortening of primary cilia. This knowledge opens up new treatment options for trauma patients with chronically elevated TGF-β1-levels (e.g., diabetics), which frequently suffer from delayed fracture healing despite adequate mechanical stimulation. KEY MESSAGES Exposure to TGF-β1 induces expression of HDAC6 in human osteoblasts. TGF-β1 exposed human osteoblasts show less and distorted primary cilia. TGF-β1 exposed human osteoblasts are less sensitive towards mechanical stimulation. Mechanosensation can be recovered by HDAC6 inhibitor Tubacin in human osteoblasts.
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Affiliation(s)
- Sabrina Ehnert
- Siegfried Weller Institute for trauma research at the BG Trauma Center, Eberhard Karls Universität Tübingen, Schnarrenbergstr. 95, 72076, Tübingen, Germany.
| | - Vrinda Sreekumar
- Siegfried Weller Institute for trauma research at the BG Trauma Center, Eberhard Karls Universität Tübingen, Schnarrenbergstr. 95, 72076, Tübingen, Germany
| | - Romina H Aspera-Werz
- Siegfried Weller Institute for trauma research at the BG Trauma Center, Eberhard Karls Universität Tübingen, Schnarrenbergstr. 95, 72076, Tübingen, Germany
| | - Sahar O Sajadian
- Siegfried Weller Institute for trauma research at the BG Trauma Center, Eberhard Karls Universität Tübingen, Schnarrenbergstr. 95, 72076, Tübingen, Germany
| | - Elke Wintermeyer
- Siegfried Weller Institute for trauma research at the BG Trauma Center, Eberhard Karls Universität Tübingen, Schnarrenbergstr. 95, 72076, Tübingen, Germany
| | - Gunther H Sandmann
- Siegfried Weller Institute for trauma research at the BG Trauma Center, Eberhard Karls Universität Tübingen, Schnarrenbergstr. 95, 72076, Tübingen, Germany
| | - Christian Bahrs
- Siegfried Weller Institute for trauma research at the BG Trauma Center, Eberhard Karls Universität Tübingen, Schnarrenbergstr. 95, 72076, Tübingen, Germany
| | - Jan G Hengstler
- IfADo-Leibniz Research Centre for Working Environment and Human Factors at the Technical University Dortmund, Ardeystraße 67, Dortmund, Germany
| | - Patricio Godoy
- IfADo-Leibniz Research Centre for Working Environment and Human Factors at the Technical University Dortmund, Ardeystraße 67, Dortmund, Germany
| | - Andreas K Nussler
- Siegfried Weller Institute for trauma research at the BG Trauma Center, Eberhard Karls Universität Tübingen, Schnarrenbergstr. 95, 72076, Tübingen, Germany
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25
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Palermo A, D'Onofrio L, Buzzetti R, Manfrini S, Napoli N. Pathophysiology of Bone Fragility in Patients with Diabetes. Calcif Tissue Int 2017; 100:122-132. [PMID: 28180919 DOI: 10.1007/s00223-016-0226-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 12/20/2016] [Indexed: 02/07/2023]
Abstract
It has been well established that bone fragility is one of the chronic complications of diabetes mellitus, and both type 1 and type 2 diabetes are risk factors for fragility fractures. Diabetes may negatively affect bone health by unbalancing several pathways: bone formation, bone resorption, collagen formation, inflammatory cytokine, muscular and incretin system, bone marrow adiposity and calcium metabolism. The purpose of this narrative review is to explore the current understanding of pathophysiological pathways underlying bone fragility in diabetics. In particular, the review will focus on the peculiar cellular and molecular system impairment that may lead to increased risk of fracture in type 1 and type 2 diabetes.
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Affiliation(s)
- Andrea Palermo
- Diabetes and Bone network, Department Endocrinology and Diabetes, University Campus Bio-Medico of Rome, Via Alvaro del Portillo, 21 - 00128, Rome, Italy
| | - Luca D'Onofrio
- Department of Experimental Medicine, Polo Pontino, Sapienza University of Rome, Rome, Italy
| | - Raffaella Buzzetti
- Department of Experimental Medicine, Polo Pontino, Sapienza University of Rome, Rome, Italy
| | - Silvia Manfrini
- Diabetes and Bone network, Department Endocrinology and Diabetes, University Campus Bio-Medico of Rome, Via Alvaro del Portillo, 21 - 00128, Rome, Italy
| | - Nicola Napoli
- Diabetes and Bone network, Department Endocrinology and Diabetes, University Campus Bio-Medico of Rome, Via Alvaro del Portillo, 21 - 00128, Rome, Italy.
- Division of Bone and Mineral Diseases, Washington University in St Louis, St Louis, USA.
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26
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Miranda C, Giner M, Montoya MJ, Vázquez MA, Miranda MJ, Pérez-Cano R. Influence of high glucose and advanced glycation end-products (ages) levels in human osteoblast-like cells gene expression. BMC Musculoskelet Disord 2016; 17:377. [PMID: 27582133 PMCID: PMC5007697 DOI: 10.1186/s12891-016-1228-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 08/23/2016] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Type 2 diabetes mellitus (T2DM) is associated with an increased risk of osteoporotic fracture. Several factors have been identified as being potentially responsible for this risk, such as alterations in bone remodelling that may have been induced by changes in circulating glucose or/and by the presence of non-oxidative end products of glycosylation (AGEs). The aim of this study is to assess whether such variations generate a change in the gene expression related to the differentiation and osteoblast activity (OPG, RANKL, RUNX2, OSTERIX, and AGE receptor) in primary cultures of human osteoblast-like cells (hOB). METHODS We recruited 32 patients; 10 patients had osteoporotic hip fractures (OP group), 12 patients had osteoporotic hip fractures with T2DM (T2DM group), and 10 patients had hip osteoarthritis (OA group) with no osteoporotic fractures and no T2DM. The gene expression was analyzed in hOB cultures treated with physiological glucose concentration (4.5 mM) as control, high glucose (25 mM), and high glucose plus AGEs (2 μg/ml) for 24 h. RESULTS The hOB cultures from patients with hip fractures presented slower proliferation. Additionally, the hOB cultures from the T2DM group were the most negatively affected with respect to RUNX2 and OSX gene expression when treated solely with high glucose or with high glucose plus AGEs. Moreover, high levels of glucose induced a major decrease in the RANKL/OPG ratio when comparing the OP and the T2DM groups to the OA group. CONCLUSIONS Our data indicates an altered bone remodelling rate in the T2DM group, which may, at least partially, explain the reduced bone strength and increased incidence of non-traumatic fractures in diabetic patients.
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Affiliation(s)
- Cristina Miranda
- Bone Metabolism Unit, Internal Medicine Department, Virgen Macarena University Hospital, Dr. Fedriani s/n, 41009 Seville, Spain
| | - Mercè Giner
- Bone Metabolism Unit, Internal Medicine Department, Virgen Macarena University Hospital, Dr. Fedriani s/n, 41009 Seville, Spain
- Medicine Department, University of Seville, Dr. Fedriani s/n, 41009 Seville, Spain
| | - M. José Montoya
- Medicine Department, University of Seville, Dr. Fedriani s/n, 41009 Seville, Spain
| | - M. Angeles Vázquez
- Medicine Department, University of Seville, Dr. Fedriani s/n, 41009 Seville, Spain
| | - M. José Miranda
- Bone Metabolism Unit, Internal Medicine Department, Virgen Macarena University Hospital, Dr. Fedriani s/n, 41009 Seville, Spain
| | - Ramón Pérez-Cano
- Bone Metabolism Unit, Internal Medicine Department, Virgen Macarena University Hospital, Dr. Fedriani s/n, 41009 Seville, Spain
- Medicine Department, University of Seville, Dr. Fedriani s/n, 41009 Seville, Spain
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27
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Wintermeyer E, Ihle C, Ehnert S, Stöckle U, Ochs G, de Zwart P, Flesch I, Bahrs C, Nussler AK. Crucial Role of Vitamin D in the Musculoskeletal System. Nutrients 2016; 8:nu8060319. [PMID: 27258303 PMCID: PMC4924160 DOI: 10.3390/nu8060319] [Citation(s) in RCA: 127] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 05/10/2016] [Accepted: 05/11/2016] [Indexed: 12/17/2022] Open
Abstract
Vitamin D is well known to exert multiple functions in bone biology, autoimmune diseases, cell growth, inflammation or neuromuscular and other immune functions. It is a fat-soluble vitamin present in many foods. It can be endogenously produced by ultraviolet rays from sunlight when the skin is exposed to initiate vitamin D synthesis. However, since vitamin D is biologically inert when obtained from sun exposure or diet, it must first be activated in human beings before functioning. The kidney and the liver play here a crucial role by hydroxylation of vitamin D to 25-hydroxyvitamin D in the liver and to 1,25-dihydroxyvitamin D in the kidney. In the past decades, it has been proven that vitamin D deficiency is involved in many diseases. Due to vitamin D’s central role in the musculoskeletal system and consequently the strong negative impact on bone health in cases of vitamin D deficiency, our aim was to underline its importance in bone physiology by summarizing recent findings on the correlation of vitamin D status and rickets, osteomalacia, osteopenia, primary and secondary osteoporosis as well as sarcopenia and musculoskeletal pain. While these diseases all positively correlate with a vitamin D deficiency, there is a great controversy regarding the appropriate vitamin D supplementation as both positive and negative effects on bone mineral density, musculoskeletal pain and incidence of falls are reported.
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Affiliation(s)
- Elke Wintermeyer
- Eberhard Karls Universität Tübingen, BG Trauma Center, Siegfried Weller Institut, Schnarrenbergstr. 95, Tübingen D-72076, Germany.
| | - Christoph Ihle
- Eberhard Karls Universität Tübingen, BG Trauma Center, Siegfried Weller Institut, Schnarrenbergstr. 95, Tübingen D-72076, Germany.
| | - Sabrina Ehnert
- Eberhard Karls Universität Tübingen, BG Trauma Center, Siegfried Weller Institut, Schnarrenbergstr. 95, Tübingen D-72076, Germany.
| | - Ulrich Stöckle
- Eberhard Karls Universität Tübingen, BG Trauma Center, Siegfried Weller Institut, Schnarrenbergstr. 95, Tübingen D-72076, Germany.
| | - Gunnar Ochs
- Eberhard Karls Universität Tübingen, BG Trauma Center, Siegfried Weller Institut, Schnarrenbergstr. 95, Tübingen D-72076, Germany.
| | - Peter de Zwart
- Eberhard Karls Universität Tübingen, BG Trauma Center, Siegfried Weller Institut, Schnarrenbergstr. 95, Tübingen D-72076, Germany.
| | - Ingo Flesch
- Eberhard Karls Universität Tübingen, BG Trauma Center, Siegfried Weller Institut, Schnarrenbergstr. 95, Tübingen D-72076, Germany.
| | - Christian Bahrs
- Eberhard Karls Universität Tübingen, BG Trauma Center, Siegfried Weller Institut, Schnarrenbergstr. 95, Tübingen D-72076, Germany.
| | - Andreas K Nussler
- Eberhard Karls Universität Tübingen, BG Trauma Center, Siegfried Weller Institut, Schnarrenbergstr. 95, Tübingen D-72076, Germany.
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Sun M, Yang J, Wang J, Hao T, Jiang D, Bao G, Liu G. TNF-α is upregulated in T2DM patients with fracture and promotes the apoptosis of osteoblast cells in vitro in the presence of high glucose. Cytokine 2016; 80:35-42. [PMID: 26945994 DOI: 10.1016/j.cyto.2016.01.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 01/17/2016] [Accepted: 01/21/2016] [Indexed: 01/21/2023]
Abstract
Fracture healing is regulated by proinflammatory mediators such as tumor necrosis factor-α (TNF-α), which poses influence on the balance between bone formation and remodeling. And the diabetes is thought to contribute to the delayed diabetic fracture healing. In the present study, we examined the promotion to proinflammatory cytokines and chemokines in type 2 diabetes mellitus (T2DM) patients with bone fractures, and then evaluated the promotion to TNF-α by the high glucose treatment in human osteoblast-like MG-63 cells and the regulatory role of the promoted TNF-α on the MG-63 cell apoptosis. It was demonstrated that there were significantly-upregulated high-sensitivity C-reactive protein (hsCRP) TNF-α, IL-1β, IL-6, IFN-γ-inducible protein 10 (IP-10) and RANTES in T2DM patients with bone fracture. And the promotion to TNF-α and IL-1β was confirmed in vitro in both mRNA and protein levels in high glucose-treated MG-63 cells. And either TNF-α or high glucose reduced the viability of MG-63 cells, promoted apoptosis and upregulated apoptosis-associated markers, such as released cytochrome c, cleaved caspase 3 and lyzed PARP. Moreover, there was a synergistic effect between TNF-α and high glucose. The viability reduction and the apoptosis induction of MG-63 cells were significantly higher in the group with both TNF-α and high glucose treatments, than in the group with singular TNF-α treatment. In conclusion, our study demonstrated that proinflammatory cytokines and chemokines were promoted in T2DM patients with bone fracture or in osteoblasts by the high glucose stimulation. TNF-α and high glucose synergistically reduced the viability and induced the apoptosis in the osteoblast-like MG-63 cells in vitro. It implies the significant regulatory role of TNF-α in the delayed fracture healing in T2DM.
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Affiliation(s)
- Mingqi Sun
- Department of Orthopaedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Junli Yang
- Medical Examination Center, The Affiliated Hospital of Inner Mongolia Medical University, Hohhot 010010, China
| | - Jianzhong Wang
- Department of Orthopedics and Trauma, The Second Affiliated Hospital of Inner Mongolia Medical University, Hohhot 010030, China
| | - Ting Hao
- Department of Orthopedics and Trauma, The Second Affiliated Hospital of Inner Mongolia Medical University, Hohhot 010030, China
| | - Dianming Jiang
- Department of Orthopaedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
| | - Guoyu Bao
- Department of Orthopedics and Trauma, The Second Affiliated Hospital of Inner Mongolia Medical University, Hohhot 010030, China.
| | - Guanghui Liu
- Department of Orthopedics and Trauma, The Second Affiliated Hospital of Inner Mongolia Medical University, Hohhot 010030, China
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Pscherer S, Kostev K, Dippel FW, Rathmann W. Fracture risk in patients with type 2 diabetes under different antidiabetic treatment regimens: a retrospective database analysis in primary care. Diabetes Metab Syndr Obes 2016; 9:17-23. [PMID: 26929655 PMCID: PMC4767062 DOI: 10.2147/dmso.s101370] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
AIM Type 2 diabetes is associated with an increased risk of fractures. There are a few studies on the effects of diabetes treatment on fracture risk. The aim was to investigate the fracture risk related to various types of insulin therapy in primary care practices. METHODS Data from 105,960 type 2 diabetes patients from 1,072 general and internal medicine practices in Germany were retrospectively analyzed (Disease Analyzer database; 01/2000-12/2013). Fracture risk of the following therapies was compared using multivariate logistic regression models adjusting for age, sex, diabetes care, comorbidity, and glycemic control (HbAlc): 1) incident insulin therapy versus oral antidiabetic drugs, 2) basal-supported oral therapy versus supplementary insulin therapy versus conventional insulin therapy, and 3) insulin glargine versus insulin detemir versus NPH insulin. RESULTS There was a lower odds of having incident fractures in the oral antidiabetic drug group compared to incident insulin users, although not significant (odds ratio [OR]; 95% confidence interval: 0.87; 0.72-1.06). There were increased odds for conventional insulin therapy (OR: 1.59; 95% CI [confidence interval] 0.89-2.84) and supplementary insulin therapy (OR: 1.20; 0.63-2.27) compared to basal-supported oral therapy, which was not significant as well. Overall, there was no significant difference in fracture risk for basal insulins (glargine, detemir, NPH insulin). After a treatment duration ≥2 years, insulin glargine showed a lower odds of having ≥1 fracture compared to NPH users (OR: 0.78; 0.65-0.95) (detemir vs NPH insulin: OR: 1.03; 0.79-1.36). CONCLUSION Long-standing therapy with insulin glargine was associated with a lower odds of having any fractures compared to NPH insulin. Further studies are required to investigate whether the lower chance is due to a reduced frequency of hypoglycemia.
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Affiliation(s)
- S Pscherer
- Department of Diabetology, Klinikum Traunstein, Kliniken Südostbayern AG, Traunstein, Germany
| | - K Kostev
- Epidemiology Department, IMS Health, Frankfurt, Germany
- Correspondence: K Kostev, Epidemiology and Evidence Based Medicine, Epidemiology Department, IMS Health, Darmstädter Landstraße 108 60598 Frankfurt am Main, Germany, Tel +49 69 6604 4878, Email
| | - FW Dippel
- Sanofi-Aventis Deutschland GmbH, Berlin, Germany
| | - W Rathmann
- German Diabetes Center, Institute for Biometrics and Epidemiology, Leibniz Center for Diabetes Research at Heinrich Heine University, Düsseldorf, Germany
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Qiao YC, Shen J, He L, Hong XZ, Tian F, Pan YH, Liang L, Zhang XX, Zhao HL. Changes of Regulatory T Cells and of Proinflammatory and Immunosuppressive Cytokines in Patients with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis. J Diabetes Res 2016; 2016:3694957. [PMID: 27777959 PMCID: PMC5061980 DOI: 10.1155/2016/3694957] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 08/09/2016] [Accepted: 08/30/2016] [Indexed: 12/18/2022] Open
Abstract
Objective. The aim of this study was to investigate the changes of regulatory T cells (Treg), interleukin-6 (IL-6), IL-10, transforming growth factor-β (TGF-β), and tumor necrosis factor-alpha (TNF-α) in patients with type 2 diabetes mellitus (T2DM). Methods. We performed a comprehensive search up to July 2016 for all clinical studies about the changes of Treg, IL-6, IL-10, IL-17, TGF-β, and TNF-α in T2DM patients versus healthy controls. Results. A total of 91 articles (5642 cases and 7378 controls) were included for this meta-analysis. Compared with the controls (all p < 0.001), the patients had increased serum levels of IL-6, TGF-β, and TNF-α but decreased the percentage of peripheral CD4+CD25+Foxp3+Treg and serum IL-10 level. Furthermore, the percentage of peripheral CD4+CD25+Foxp3+Treg (p < 0.001) and serum IL-10 level (p = 0.033) were significantly lower in the patients with complication and in the patients without complication, respectively. No significant changes about the percentage of CD4+CD25+Treg (p = 0.360) and serum IL-17 level (p = 0.459) were found in T2DM patients. Conclusions. T2DM patients have decreased the percentage of peripheral CD4+CD25+Foxp3+Treg and levels of serum IL-10 but elevated serum levels of IL-6, TGF-β, and TNF-α. Presence of diabetic complications further lowers the peripheral CD4+CD25+Foxp3+Treg number.
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Affiliation(s)
- Yong-chao Qiao
- Diabetic Systems Medicine, Guangxi Key Laboratory of Excellence, Guilin Medical University, Guilin 541004, China
- Department of Immunology, School of Basic Medical Sciences, Central South University, Changsha, Hunan 410078, China
| | - Jian Shen
- Diabetic Systems Medicine, Guangxi Key Laboratory of Excellence, Guilin Medical University, Guilin 541004, China
| | - Lan He
- Department of Microbiology, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Xue-zhi Hong
- Diabetic Systems Medicine, Guangxi Key Laboratory of Excellence, Guilin Medical University, Guilin 541004, China
| | - Fang Tian
- Department of Immunology, School of Basic Medical Sciences, Central South University, Changsha, Hunan 410078, China
| | - Yan-hong Pan
- Diabetic Systems Medicine, Guangxi Key Laboratory of Excellence, Guilin Medical University, Guilin 541004, China
| | - Ling Liang
- Diabetic Systems Medicine, Guangxi Key Laboratory of Excellence, Guilin Medical University, Guilin 541004, China
| | - Xiao-xi Zhang
- Diabetic Systems Medicine, Guangxi Key Laboratory of Excellence, Guilin Medical University, Guilin 541004, China
- Department of Immunology, Faculty of Basic Medicine, Guilin Medical University, Guilin 541004, China
| | - Hai-lu Zhao
- Diabetic Systems Medicine, Guangxi Key Laboratory of Excellence, Guilin Medical University, Guilin 541004, China
- Department of Immunology, School of Basic Medical Sciences, Central South University, Changsha, Hunan 410078, China
- Department of Immunology, Faculty of Basic Medicine, Guilin Medical University, Guilin 541004, China
- *Hai-lu Zhao:
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31
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Ehnert S, Falldorf K, Fentz AK, Ziegler P, Schröter S, Freude T, Ochs BG, Stacke C, Ronniger M, Sachtleben J, Nussler AK. Primary human osteoblasts with reduced alkaline phosphatase and matrix mineralization baseline capacity are responsive to extremely low frequency pulsed electromagnetic field exposure - Clinical implication possible. Bone Rep 2015; 3:48-56. [PMID: 28377966 PMCID: PMC5365212 DOI: 10.1016/j.bonr.2015.08.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/07/2015] [Accepted: 08/12/2015] [Indexed: 01/15/2023] Open
Abstract
For many years electromagnetic fields (EMFs) have been used clinically with various settings as an exogenous stimulation method to promote fracture healing. However, underlying mechanisms of action and EMF parameters responsible for certain effects remain unclear. Our aim was to investigate the influence of defined EMFs on human osteoblasts' and osteoclasts' viability and function. Primary human osteoblasts and osteoclasts were treated 3 times weekly for 21 days during their maturation process using the Somagen® device (Sachtleben GmbH, Hamburg, Germany), generating defined extremely low-frequency pulsed electromagnetic fields (ELF-PEMFs). Certain ELF-PEMF treatment significantly increased the total protein content (up to 66%), mitochondrial activity (up to 91.1%) and alkaline phosphatase (AP) activity (up to 129.9%) of human osteoblasts during the entire differentiation process. Furthermore, ELF-PEMF treatment enhanced formation of mineralized matrix (up to 276%). Interestingly, ELF-PEMF dependent induction of AP activity and matrix mineralization was strongly donor dependent — only osteoblasts with a poor initial osteoblast function responded to the ELF-PEMF treatment. As a possible regulatory mechanism, activation of the ERK1/2 signaling pathway was identified. Maturation of osteoclasts from human monocytes was not affected by the ELF-PEMF treatment. In summary the results indicate that a specific ELF-PEMF treatment with the Somagen® device improves viability and maturation of osteoblasts, while osteoclast viability and maturation was not affected. Hence, ELF-PEMF might represent an interesting adjunct to conventional therapy supporting bone formation during fracture healing or even for the treatment of osteoporosis. Exposure to extremely low-frequency pulsed electromagnetic fields (ELF-PEMFs) increases viability of human osteoblasts. Exposure to specific ELF-PEMFs improves primary human osteoblasts’ function. Especially osteoblasts with a low differentiation capacity profit from the ELF-PEMF exposure. For the observed effects ERK1/2 activation is pivotal. Osteoclast viability and function is not affected by the same ELF-PEMF.
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Affiliation(s)
- Sabrina Ehnert
- Siegfried Weller Institute for Trauma Research, Eberhard-Karls-Universität Tübingen, Schnarrenbergstr. 95, 72076 Tübingen, Germany
| | | | | | - Patrick Ziegler
- Siegfried Weller Institute for Trauma Research, Eberhard-Karls-Universität Tübingen, Schnarrenbergstr. 95, 72076 Tübingen, Germany
| | - Steffen Schröter
- Siegfried Weller Institute for Trauma Research, Eberhard-Karls-Universität Tübingen, Schnarrenbergstr. 95, 72076 Tübingen, Germany
| | - Thomas Freude
- Siegfried Weller Institute for Trauma Research, Eberhard-Karls-Universität Tübingen, Schnarrenbergstr. 95, 72076 Tübingen, Germany
| | - Björn G Ochs
- Siegfried Weller Institute for Trauma Research, Eberhard-Karls-Universität Tübingen, Schnarrenbergstr. 95, 72076 Tübingen, Germany
| | | | | | | | - Andreas K Nussler
- Siegfried Weller Institute for Trauma Research, Eberhard-Karls-Universität Tübingen, Schnarrenbergstr. 95, 72076 Tübingen, Germany
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