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Sekulovski N, Whorton AE, Shi M, Hayashi K, MacLean JA. Insulin signaling is an essential regulator of endometrial proliferation and implantation in mice. FASEB J 2021; 35:e21440. [PMID: 33749878 DOI: 10.1096/fj.202002448r] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/27/2021] [Accepted: 01/29/2021] [Indexed: 01/04/2023]
Abstract
Insulin signaling is critical for the development of preovulatory follicles and progression through the antral stage. Using a conditional knockout model that escapes this blockage, we recently described the role of insulin signaling in granulosa cells during the periovulatory window in mice lacking Insr and Igf1r driven by Pgr-Cre. These mice were infertile, exhibiting defects in ovulation, luteinization, steroidogenesis, and early embryo development. Herein, we demonstrate that while these mice exhibit normal uterine receptivity, uterine cell proliferation and decidualization are compromised resulting in complete absence of embryo implantation in uteri lacking both receptors. While the histological organization of double knockout mice appeared normal, the thickness of their endometrium was significantly reduced. This was supported by the reduced proliferation of both epithelial and stromal cells during the preimplantation stages of pregnancy. Expression and localization of the main drivers of uterine proliferation, ESR1 and PGR, was normal in knockouts, suggesting that insulin signaling acts downstream of these two receptors. While AKT/PI3K signaling was unaffected by insulin receptor ablation, activation of p44/42 MAPK was significantly reduced in both single and double knockout uteri at 3.5 dpc. Overall, we conclude that both INSR and IGF1R are necessary for optimal endometrial proliferation and implantation.
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Affiliation(s)
- Nikola Sekulovski
- Department of Physiology, Southern Illinois School of Medicine, Carbondale, IL, USA
| | - Allison E Whorton
- Department of Physiology, Southern Illinois School of Medicine, Carbondale, IL, USA
| | - Mingxin Shi
- Department of Physiology, Southern Illinois School of Medicine, Carbondale, IL, USA
| | - Kanako Hayashi
- Department of Physiology, Southern Illinois School of Medicine, Carbondale, IL, USA.,Center for Reproductive Biology, Washington State University, Pullman, WA, USA
| | - James A MacLean
- Department of Physiology, Southern Illinois School of Medicine, Carbondale, IL, USA.,Center for Reproductive Biology, Washington State University, Pullman, WA, USA.,School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
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2
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Mori Y, Gonzalez Medina M, Liu Z, Guo J, Dingwell LS, Chiang S, Kahn CR, Husain M, Giacca A. Roles of vascular endothelial and smooth muscle cells in the vasculoprotective effect of insulin in a mouse model of restenosis. Diab Vasc Dis Res 2021; 18:14791641211027324. [PMID: 34190643 PMCID: PMC8482728 DOI: 10.1177/14791641211027324] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Insulin exerts vasculoprotective effects on endothelial cells (ECs) and growth-promoting effects on vascular smooth muscle cells (SMCs) in vitro, and suppresses neointimal growth in vivo. Here we determined the role of ECs and SMCs in the effect of insulin on neointimal growth. METHODS Mice with transgene CreERT2 under the control of EC-specific Tie2 (Tie2-Cre) or SMC-specific smooth muscle myosin heavy chain promoter/enhancer (SMMHC-Cre) or littermate controls were crossbred with mice carrying a loxP-flanked insulin receptor (IR) gene. After CreERT2-loxP-mediated recombination was induced by tamoxifen injection, mice received insulin pellet or sham (control) implantation, and underwent femoral artery wire injury. Femoral arteries were collected for morphological analysis 28 days after wire injury. RESULTS Tamoxifen-treated Tie2-Cre+ mice showed lower IR expression in ECs, but not in SMCs, than Tie2-Cre- mice. Insulin treatment reduced neointimal area after arterial injury in Tie2-Cre- mice, but had no effect in Tie2-Cre+ mice. Tamoxifen-treated SMMHC-Cre+ mice showed lower IR expression in SMCs, but not in ECs, than SMMHC-Cre- mice. Insulin treatment reduced neointimal area in SMMHC-Cre- mice, whereas unexpectedly, it failed to inhibit neointima formation in SMMHC-Cre+ mice. CONCLUSION Insulin action in both ECs and SMCs is required for the "anti-restenotic" effect of insulin in vivo.
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MESH Headings
- Animals
- Disease Models, Animal
- Drug Implants
- Endothelial Cells/drug effects
- Endothelial Cells/metabolism
- Endothelial Cells/pathology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/injuries
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/pathology
- Femoral Artery/drug effects
- Femoral Artery/injuries
- Femoral Artery/metabolism
- Femoral Artery/pathology
- Hypoglycemic Agents/administration & dosage
- Insulin/administration & dosage
- Male
- Mice, Knockout
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/injuries
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Neointima
- Receptor, Insulin/agonists
- Receptor, Insulin/genetics
- Receptor, Insulin/metabolism
- Vascular System Injuries/drug therapy
- Vascular System Injuries/metabolism
- Vascular System Injuries/pathology
- Mice
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Affiliation(s)
- Yusaku Mori
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Division of Diabetes, Metabolism, and Endocrinology, Anti-Glycation Research Section, Department of Medicine, Showa University School of Medicine, Shinagawa, Tokyo, Japan
| | - Marel Gonzalez Medina
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Zhiwei Liu
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - June Guo
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Luke S Dingwell
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Simon Chiang
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | | | - Mansoor Husain
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Department of Medicine, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Adria Giacca
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Department of Medicine, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Banting and Best Diabetes Centre, University of Toronto, Toronto, ON, Canada
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3
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Hyperglycemia-induced transcriptional regulation of ROCK1 and TGM2 expression is involved in small artery remodeling in obese diabetic Göttingen Minipigs. Clin Sci (Lond) 2020; 133:2499-2516. [PMID: 31830262 DOI: 10.1042/cs20191066] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/11/2019] [Accepted: 12/12/2019] [Indexed: 12/11/2022]
Abstract
Obesity and diabetes in humans are associated with hypertrophic remodeling and increased media:lumen ratio of small resistance arteries, which is an independent predictor of cardiovascular events. In order to minimize increases in media:lumen ratio, hypertrophic remodeling should be accompanied by outward remodeling. We aimed to investigate the mechanisms of structural remodeling in small pial arteries (PAs) and terminal mesenteric arteries (TMAs) from obese Göttingen Minipigs with or without diabetes. Göttingen Minipigs received either control diet (lean control (LC)), high fat/high fructose/high cholesterol diet (FFC), or FFC diet with streptozotocin (STZ)-induced diabetes (FFC/STZ) for 13 months. At the end of the study (20 months), we assessed body weight, fasting plasma biochemistry, passive vessel dimensions, mRNA expression (matrix metallopeptidases 2/9 (MMP2, MMP9), tissue inhibitor of metallopeptidase 1 (TIMP1), transglutaminase 2 (TGM2), Rho-kinase 1 (ROCK1), TGFβ-receptor 2 (TGFBR2), and IGF1-receptor (IGFR1) genes), and immunofluorescence in PAs and TMAs. We performed multiple linear correlation analyses using plasma values, structural data, and gene expression data. We detected outward hypertrophic remodeling in TMAs and hypertrophic remodeling in PAs from FFC/STZ animals. ROCK1 and TGM2 genes were up-regulated in PAs and TMAs from the FFC/STZ group. Passive lumen diameter (PLD) of TMAs was correlated with plasma values of glucose (GLU), fructosamine (FRA), total cholesterol (TC), and triglycerides (TGs). ROCK1 and TGM2 expressions in TMAs were correlated with PLD, plasma GLU, fructosamine, and TC. ROCK1 and TGM2 proteins were immunolocalized in the media of PAs and TMAs, and their fluorescence levels were increased in the FFC/STZ group. Hyperglycemia/hyperlipidemia is involved in regulation of ROCK1 and TGM2 expression leading to outward remodeling of small resistance arteries in obese diabetic Göttingen Minipigs.
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4
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Selective inhibition of PKR improves vascular inflammation and remodelling in high fructose treated primary vascular smooth muscle cells. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165606. [DOI: 10.1016/j.bbadis.2019.165606] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 10/25/2019] [Accepted: 11/11/2019] [Indexed: 12/14/2022]
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5
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Selig JI, Ouwens DM, Raschke S, Thoresen GH, Fischer JW, Lichtenberg A, Akhyari P, Barth M. Impact of hyperinsulinemia and hyperglycemia on valvular interstitial cells - A link between aortic heart valve degeneration and type 2 diabetes. Biochim Biophys Acta Mol Basis Dis 2019; 1865:2526-2537. [PMID: 31152868 DOI: 10.1016/j.bbadis.2019.05.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 04/27/2019] [Accepted: 05/28/2019] [Indexed: 12/11/2022]
Abstract
Type 2 diabetes is a known risk factor for cardiovascular diseases and is associated with an increased risk to develop aortic heart valve degeneration. Nevertheless, molecular mechanisms leading to the pathogenesis of valve degeneration in the context of diabetes are still not clear. Hence, we hypothesized that classical key factors of type 2 diabetes, hyperinsulinemia and hyperglycemia, may affect signaling, metabolism and degenerative processes of valvular interstitial cells (VIC), the main cell type of heart valves. Therefore, VIC were derived from sheep and were treated with hyperinsulinemia, hyperglycemia and the combination of both. The presence of insulin receptors was shown and insulin led to increased proliferation of the cells, whereas hyperglycemia alone showed no effect. Disturbed insulin response was shown by impaired insulin signaling, i.e. by decreased phosphorylation of Akt/GSK-3α/β pathway. Analysis of glucose transporter expression revealed absence of glucose transporter 4 with glucose transporter 1 being the predominantly expressed transporter. Glucose uptake was not impaired by disturbed insulin response, but was increased by hyperinsulinemia and was decreased by hyperglycemia. Analyses of glycolysis and mitochondrial respiration revealed that VIC react with increased activity to hyperinsulinemia or hyperglycemia, but not to the combination of both. VIC do not show morphological changes and do not acquire an osteogenic phenotype by hyperinsulinemia or hyperglycemia. However, the treatment leads to increased collagen type 1 and decreased α-smooth muscle actin expression. This work implicates a possible role of diabetes in early phases of the degeneration of aortic heart valves.
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Affiliation(s)
- Jessica I Selig
- Department of Cardiovascular Surgery, Medical Faculty, University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany.
| | - D Margriet Ouwens
- Institute of Clinical Biochemistry and Pathobiochemistry, German Diabetes Center, Düsseldorf, Germany; German Center for Diabetes Research, München-Neuherberg, Germany; Department of Endocrinology, Ghent University Hospital, Ghent, Belgium.
| | - Silja Raschke
- Department of Cardiovascular Surgery, Medical Faculty, University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany
| | - G Hege Thoresen
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway; Department of Pharmacology, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
| | - Jens W Fischer
- Department of Pharmacology and Clinical Pharmacology, Medical Faculty, University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany.
| | - Artur Lichtenberg
- Department of Cardiovascular Surgery, Medical Faculty, University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany.
| | - Payam Akhyari
- Department of Cardiovascular Surgery, Medical Faculty, University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany.
| | - Mareike Barth
- Department of Cardiovascular Surgery, Medical Faculty, University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany.
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Zhang J, Chen Q, Zhong J, Liu C, Zheng B, Gong Q. DPP-4 Inhibitors as Potential Candidates for Antihypertensive Therapy: Improving Vascular Inflammation and Assisting the Action of Traditional Antihypertensive Drugs. Front Immunol 2019; 10:1050. [PMID: 31134095 PMCID: PMC6526751 DOI: 10.3389/fimmu.2019.01050] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 04/24/2019] [Indexed: 12/12/2022] Open
Abstract
Dipeptidyl peptidase-4 (DPP-4) is an important protease that is widely expressed on the surface of human cells and plays a key role in immune-regulation, inflammation, oxidative stress, cell adhesion, and apoptosis by targeting different substrates. DPP-4 inhibitors (DPP-4i) are commonly used as hypoglycemic agents. However, in addition to their hypoglycemic effect, DPP-4i have also shown potent activities in the cardiovascular system, particularly in the regulation of blood pressure (BP). Previous studies have shown that the regulatory actions of DPP-4i in controlling BP are complex and that the mechanisms involved include the functional activities of the nerves, kidneys, hormones, blood vessels, and insulin. Recent work has also shown that inflammation is closely associated with the elevation of BP, and that the inhibition of DPP-4 can reduce BP by regulating the function of the immune system, by reducing inflammatory reactions and by improving oxidative stress. In this review, we describe the potential anti-hypertensive effects of DPP-4i and discuss potential new anti-hypertensive therapies. Our analysis indicated that DPP-4i treatment has a mild anti-hypertensive effect as a monotherapy and causes a significant reduction in BP when used in combined treatments. However, the combination of DPP-4i with high-dose angiotensin converting enzyme inhibitors (ACEI) can lead to increased BP. We suggest that DPP-4i improves vascular endothelial function in hypertensive patients by suppressing inflammatory responses and by alleviating oxidative stress. In addition, DPP-4i can also regulate BP by activating the sympathetic nervous system, interfering with the renin angiotensin aldosterone system (RAAS), regulating Na/H2O metabolism, and attenuating insulin resistance (IR).
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Affiliation(s)
- Jianqiang Zhang
- Department of Immunology, School of Medicine, Yangtze University, Jingzhou, China
| | - Qiuyue Chen
- Department of Immunology, School of Medicine, Yangtze University, Jingzhou, China
| | - Jixin Zhong
- Cardiovascular Research Institute, Case Western Reserve University, Cleveland, OH, United States
| | - Chaohong Liu
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, China
| | - Bing Zheng
- Department of Immunology, School of Medicine, Yangtze University, Jingzhou, China.,Clinical Molecular Immunology Center, School of Medicine, Yangtze University, Jingzhou, China
| | - Quan Gong
- Department of Immunology, School of Medicine, Yangtze University, Jingzhou, China.,Clinical Molecular Immunology Center, School of Medicine, Yangtze University, Jingzhou, China
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7
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Bacopoulou F, Athanasopoulos N, Efthymiou V, Mantzou A, Aravantinos L, Vlahopoulos S, Deligeoroglou E. Serum irisin concentrations in lean adolescents with polycystic ovary syndrome. Clin Endocrinol (Oxf) 2018; 88:585-591. [PMID: 29368340 DOI: 10.1111/cen.13555] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 01/12/2018] [Accepted: 01/15/2018] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To explore differences in irisin concentrations between lean adolescents with PCOS and age- and body mass index (BMI)-matched controls and examine the associations of irisin with core features of the syndrome. DESIGN Cross-sectional study. PATIENTS Lean females with PCOS, aged 13-21 years. MEASUREMENTS Physical, hormonal and sonographic assessment. Irisin concentrations were measured with ELISA. RESULTS Participants included in total 39 sedentary females (mean ± SD; age 17.3 ± 2.1 years, BMI 20.7 ± 1.3 Kg/m2 ), 23 adolescents with PCOS and 16 controls. Adolescents with PCOS compared to controls had significantly elevated concentrations of fasting serum irisin (mean ± SD; PCOS, 1.7 ± 1.0 μg/mL vs controls, 1.0 ± 0.4 μg/mL; P = .007), luteinizing hormone (LH), oestradiol, testosterone, Δ4-androstenedione, 17-hydroxyprogesterone, glucose, as well as free androgen index, Ferriman-Gallwey score and mean ovarian volume (MOV). For the total sample, circulating irisin was positively correlated with MOV (r = .332, P = .041), glucose (r = .428, P = .007), insulin (rs = .369, P = .021) and HOMA-IR (rs = .422, P = .007) and negatively correlated with QUICKI (r = -.329, P = .041). Follicle-stimulating hormone (B = 0.295, Beta = .342, P = .042) and MOV (B = 0.182, Beta = 0.821, P = .001) were positive predictors, and LH (B = -0.108, Beta = -0.523, P = .010) and testosterone (B = -0.431, Beta = -0.457, P = .032) were negative predictors of irisin concentrations, whereas irisin positively predicted fasting glucose (B = 0.262, Beta = 0.428, P = .007). In the PCOS group, irisin concentrations were positively correlated with HOMA-IR (rs = .416, P = .048) but negatively correlated with LH (rs = -.499, P = .015), testosterone (r = -.585, P = .003), free androgen index (r = -.426, P = .048) and Ferriman-Gallwey score (r = -.533, P = .015). CONCLUSIONS Irisin was associated with the adolescents' metabolic and reproductive characteristics and the hyperandrogenic phenotype of the syndrome. Much research is needed to ascertain mechanisms of elevated serum irisin in adolescent PCOS.
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Affiliation(s)
- Flora Bacopoulou
- Center for Adolescent Medicine and UNESCO Chair on Adolescent Health Care, First Department of Pediatrics, School of Medicine, National and Kapodistrian University of Athens, Aghia Sophia Children's Hospital, Athens, Greece
- Unit of Clinical and Translational Research in Endocrinology, First Department of Pediatrics, School of Medicine, National and Kapodistrian University of Athens, Aghia Sophia Children's Hospital, Athens, Greece
| | - Nikos Athanasopoulos
- Division of Pediatric-Adolescent Gynecology and Reconstructive Surgery, Second Department of Obstetrics and Gynecology, School of Medicine, National and Kapodistrian University of Athens, Aretaieion Hospital, Athens, Greece
| | - Vasiliki Efthymiou
- Center for Adolescent Medicine and UNESCO Chair on Adolescent Health Care, First Department of Pediatrics, School of Medicine, National and Kapodistrian University of Athens, Aghia Sophia Children's Hospital, Athens, Greece
| | - Aimilia Mantzou
- Unit of Clinical and Translational Research in Endocrinology, First Department of Pediatrics, School of Medicine, National and Kapodistrian University of Athens, Aghia Sophia Children's Hospital, Athens, Greece
| | - Leon Aravantinos
- Ultrasound and Fetal Medicine Unit, Second Department of Obstetrics and Gynecology, School of Medicine, National and Kapodistrian University of Athens, Aretaieion Hospital, Athens, Greece
| | - Spiros Vlahopoulos
- Center for Adolescent Medicine and UNESCO Chair on Adolescent Health Care, First Department of Pediatrics, School of Medicine, National and Kapodistrian University of Athens, Aghia Sophia Children's Hospital, Athens, Greece
| | - Efthymios Deligeoroglou
- Division of Pediatric-Adolescent Gynecology and Reconstructive Surgery, Second Department of Obstetrics and Gynecology, School of Medicine, National and Kapodistrian University of Athens, Aretaieion Hospital, Athens, Greece
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Vardar E, Larsson H, Allazetta S, Engelhardt E, Pinnagoda K, Vythilingam G, Hubbell J, Lutolf M, Frey P. Microfluidic production of bioactive fibrin micro-beads embedded in crosslinked collagen used as an injectable bulking agent for urinary incontinence treatment. Acta Biomater 2018; 67:156-166. [PMID: 29197579 DOI: 10.1016/j.actbio.2017.11.034] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 11/19/2017] [Accepted: 11/20/2017] [Indexed: 01/12/2023]
Abstract
Endoscopic injection of bulking agents has been widely used to treat urinary incontinence, often due to urethral sphincter complex insufficiency. The aim of the study was to develop a novel injectable bioactive collagen-fibrin bulking agent restoring long-term continence by functional muscle tissue regeneration. Fibrin micro-beads were engineered using a droplet microfluidic system. They had an average diameter of 140 μm and recombinant fibrin-binding insulin-like growth factor-1 (α2PI1-8-MMP-IGF-1) was covalently conjugated to the beads. A plasmin fibrin degradation assay showed that 72.5% of the initial amount of α2PI1-8-MMP-IGF-1 loaded into the micro-beads was retained within the fibrin micro-beads. In vitro, the growth factor modified fibrin micro-beads enhanced cell attachment and the migration of human urinary tract smooth muscle cells, however, no change of the cellular metabolic activity was seen. These bioactive micro-beads were mixed with genipin-crosslinked homogenized collagen, acting as a carrier. The collagen concentration, the degree of crosslinking, and the mechanical behavior of this bioactive collagen-fibrin injectable were comparable to reference samples. This novel injectable showed no burst release of the growth factor, had a positive effect on cell behavior and may therefore induce smooth muscle regeneration in vivo, necessary for the functional treatment of stress and other urinary incontinences. STATEMENT OF SIGNIFICANCE Urinary incontinence is involuntary urine leakage, resulting from a deficient function of the sphincter muscle complex. Yet there is no functional cure for this devastating condition using current treatment options. Applied physical and surgical therapies have limited success. In this study, a novel bioactive injectable bulking agent, triggering new muscle regeneration at the injection site, has been evaluated. This injectable consists of cross-linked collagen and fibrin micro-beads, functionalized with bound insulin-like growth factor-1 (α2PI1-8-MMP-IGF-1). These bioactive fibrin micro-beads induced human smooth muscle cell migration in vitro. Thus, this injectable bulking agent is apt to be a good candidate for regeneration of urethral sphincter muscle, ensuring a long-lasting treatment for urinary incontinence.
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Brar PC, Patel P, Katz S. The relationship between insulin resistance and endothelial dysfunction in obese adolescents. J Pediatr Endocrinol Metab 2017; 30:635-642. [PMID: 28525354 DOI: 10.1515/jpem-2016-0404] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 04/03/2017] [Indexed: 11/15/2022]
Abstract
BACKGROUND Insulin resistance and endothelial dysfunction share a reciprocal relationship that links the metabolic and cardiovascular sequelae of obesity. We characterized the brachial artery reactivity testing (BART) and carotid artery-intima media thickness (CIMT) in adolescents categorized as obese insulin resistant (OIR) and obese not insulin resistant (ONIR). Lipoprotein particle (p) analysis and inflammatory cytokines in OIR and ONIR groups were also analyzed. METHODS Obese adolescents (n=40; mean body mass index [BMI] 35.6) were categorized as ONIR and OIR based on their homeostatic model assessment of insulin resistance (HOMA-IR) calculation (≤or> than 3.4). Ultrasound measured conduit arterial function BART, microvascular function (post-ischemic hyperemia) and conduit artery structure CIMT. RESULTS BART did not differ according to IR status (mean±SD: 7.0±4.3% vs. 5.9±3.4% in ONIR and OIR, respectively, p=0.3, but post-ischemic hyperemia was significantly greater in the ONIR group (4.5±2.2 vs. 3.5±3, p=0.04). Atherogenic lipoprotein particles; large VLDL particles and small LDL particles were higher in the OIR compared to ONIR group. CONCLUSIONS OIR adolescents demonstrate an inflamed atherogenic milieu compared to the ONIR adolescents. Microvascular function, but not conduit vessel structure or function, was impaired in association with IR.
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10
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Zhang Y, Sun X, Icli B, Feinberg MW. Emerging Roles for MicroRNAs in Diabetic Microvascular Disease: Novel Targets for Therapy. Endocr Rev 2017; 38:145-168. [PMID: 28323921 PMCID: PMC5460677 DOI: 10.1210/er.2016-1122] [Citation(s) in RCA: 128] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 02/13/2017] [Indexed: 12/11/2022]
Abstract
Chronic, low-grade systemic inflammation and impaired microvascular function are critical hallmarks in the development of insulin resistance. Accordingly, insulin resistance is a major risk factor for type 2 diabetes and cardiovascular disease. Accumulating studies demonstrate that restoration of impaired function of the diabetic macro- and microvasculature may ameliorate a range of cardiovascular disease states and diabetes-associated complications. In this review, we focus on the emerging role of microRNAs (miRNAs), noncoding RNAs that fine-tune target gene expression and signaling pathways, in insulin-responsive tissues and cell types important for maintaining optimal vascular homeostasis and preventing the sequelae of diabetes-induced end organ injury. We highlight current pathophysiological paradigms of miRNAs and their targets involved in regulating the diabetic microvasculature in a range of diabetes-associated complications such as retinopathy, nephropathy, wound healing, and myocardial injury. We provide an update of the potential use of circulating miRNAs diagnostically in type I or type II diabetes. Finally, we discuss emerging delivery platforms for manipulating miRNA expression or function as the next frontier in therapeutic intervention to improve diabetes-associated microvascular dysfunction and its attendant clinical consequences.
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Affiliation(s)
- Yu Zhang
- Department of Medicine, Cardiovascular Division, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115
- Department of Pharmacology and Pharmacy, University of Hong Kong, Pokfulam, Hong Kong SAR, China, and
| | - Xinghui Sun
- Department of Medicine, Cardiovascular Division, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| | - Basak Icli
- Department of Medicine, Cardiovascular Division, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Mark W. Feinberg
- Department of Medicine, Cardiovascular Division, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115
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11
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Escribano O, Beneit N, Rubio-Longás C, López-Pastor AR, Gómez-Hernández A. The Role of Insulin Receptor Isoforms in Diabetes and Its Metabolic and Vascular Complications. J Diabetes Res 2017; 2017:1403206. [PMID: 29201918 PMCID: PMC5671728 DOI: 10.1155/2017/1403206] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 09/12/2017] [Accepted: 09/25/2017] [Indexed: 12/18/2022] Open
Abstract
The insulin receptor (IR) presents by alternative splicing two isoforms: IRA and IRB. The differential physiological and pathological role of both isoforms is not completely known, and it is determinant the different binding affinity for insulin-like growth factor. IRB is more abundant in adult tissues and it exerts mainly the metabolic actions of insulin, whereas IRA is mainly expressed in fetal and prenatal period and exerts mitogenic actions. However, the change in the expression profile of both IR isoforms and its dysregulation are associated with the development of different pathologies, such as cancer, insulin resistance, diabetes, obesity, and atherosclerosis. In some of them, there is a significant increase of IRA/IRB ratio conferring a proliferative and migratory advantage to different cell types and favouring IGF-II actions with a sustained detriment in the metabolic effects of insulin. This review discussed specifically the role of IR isoforms as well as IGF-IR in diabetes and its associated complications as obesity and atherosclerosis. Future research with new IR modulators might be considered as possible targets to improve the treatment of diabetes and its associated complications.
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Affiliation(s)
- O. Escribano
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Madrid, Spain
- Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain
- CIBER of Diabetes and Associated Metabolic Diseases, Madrid, Spain
| | - N. Beneit
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Madrid, Spain
- Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain
- CIBER of Diabetes and Associated Metabolic Diseases, Madrid, Spain
| | - C. Rubio-Longás
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Madrid, Spain
| | - A. R. López-Pastor
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Madrid, Spain
| | - A. Gómez-Hernández
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Madrid, Spain
- Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain
- CIBER of Diabetes and Associated Metabolic Diseases, Madrid, Spain
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12
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Beneit N, Fernández-García CE, Martín-Ventura JL, Perdomo L, Escribano Ó, Michel JB, García-Gómez G, Fernández S, Díaz-Castroverde S, Egido J, Gómez-Hernández A, Benito M. Expression of insulin receptor (IR) A and B isoforms, IGF-IR, and IR/IGF-IR hybrid receptors in vascular smooth muscle cells and their role in cell migration in atherosclerosis. Cardiovasc Diabetol 2016; 15:161. [PMID: 27905925 PMCID: PMC5134076 DOI: 10.1186/s12933-016-0477-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 11/22/2016] [Indexed: 01/02/2023] Open
Abstract
Background Abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) is a major contributor to the development of atherosclerotic process. In a previous work, we demonstrated that the insulin receptor isoform A (IRA) and its association with the insulin-like growth factor-I receptor (IGF-IR) confer a proliferative advantage to VSMCs. However, the role of IR and IGF-IR in VSMC migration remains poorly understood. Methods Wound healing assays were performed in VSMCs bearing IR (IRLoxP+/+ VSMCs), or not (IR−/− VSMCs), expressing IRA (IRA VSMCs) or expressing IRB (IRB VSMCs). To study the role of IR isoforms and IGF-IR in experimental atherosclerosis, we used ApoE−/− mice at 8, 12, 18 and 24 weeks of age. Finally, we analyzed the mRNA expression of total IR, IRB isoform, IGF-IR and IGFs by qRT-PCR in the medial layer of human aortas. Results IGF-I strongly induced migration of the four cell lines through IGF-IR. In contrast, insulin and IGF-II only caused a significant increase of IRA VSMC migration which might be favored by the formation of IRA/IGF-IR receptors. Additionally, a specific IGF-IR inhibitor, picropodophyllin, completely abolished insulin- and IGF-II-induced migration in IRB, but not in IRA VSMCs. A significant increase of IRA and IGF-IR, and VSMC migration were observed in fibrous plaques from 24-week-old ApoE−/− mice. Finally, we observed a marked increase of IGF-IR, IGF-I and IGF-II in media from fatty streaks as compared with both healthy aortas and fibrolipidic lesions, favoring the ability of medial VSMCs to migrate into the intima. Conclusions Our data suggest that overexpression of IGF-IR or IRA isoform, as homodimers or as part of IRA/IGF-IR hybrid receptors, confers a stronger migratory capability to VSMCs as might occur in early stages of atherosclerotic process. Electronic supplementary material The online version of this article (doi:10.1186/s12933-016-0477-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- N Beneit
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain.,Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain.,CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Barcelona, Spain
| | - C E Fernández-García
- Vascular Research Lab, IIS-Fundación Jiménez Diaz-Autonoma University, Madrid, Spain
| | - J L Martín-Ventura
- Vascular Research Lab, IIS-Fundación Jiménez Diaz-Autonoma University, Madrid, Spain
| | - L Perdomo
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain.,Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain.,CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Barcelona, Spain
| | - Ó Escribano
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain.,Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain.,CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Barcelona, Spain
| | - J B Michel
- Inserm, U698, Universite Paris 7, CHU X-Bichat, Paris, France
| | - G García-Gómez
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain.,Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain.,CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Barcelona, Spain
| | - S Fernández
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain.,Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain.,CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Barcelona, Spain
| | - S Díaz-Castroverde
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain.,Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain.,CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Barcelona, Spain
| | - J Egido
- CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Barcelona, Spain.,Vascular Research Lab, IIS-Fundación Jiménez Diaz-Autonoma University, Madrid, Spain
| | - A Gómez-Hernández
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain. .,Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain. .,CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Barcelona, Spain.
| | - M Benito
- Biochemistry and Molecular Biology II Department, School of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain.,Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain.,CIBER of Diabetes and Associated Metabolic Diseases (CIBERDEM), Barcelona, Spain
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13
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Jahn LA, Hartline L, Rao N, Logan B, Kim JJ, Aylor K, Gan LM, Westergren HU, Barrett EJ. Insulin Enhances Endothelial Function Throughout the Arterial Tree in Healthy But Not Metabolic Syndrome Subjects. J Clin Endocrinol Metab 2016; 101:1198-206. [PMID: 26756115 PMCID: PMC4803154 DOI: 10.1210/jc.2015-3293] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
CONTEXT Insulin reportedly impairs endothelial function in conduit arteries but improves it in resistance and microvascular arterioles in healthy humans. No studies have assessed endothelial function at three arterial levels in healthy or metabolic syndrome (METSYN) subjects. OBJECTIVE The objective of the study was to compare endothelial responsiveness of conduit arteries, resistance, and microvascular arterioles to insulin in healthy and METSYN subjects. DESIGN We assessed conduit, resistance, and microvascular arterial function in the postabsorptive and postprandial states and during euglycemic hyperinsulinemia (insulin clamp). SETTING The study was conducted at a clinical research unit. PARTICIPANTS Age-matched healthy and METSYN subjects participated in the study. INTERVENTIONS We used brachial flow-mediated dilation, forearm postischemic flow velocity, and contrast-enhanced ultrasound to assess the conduit artery, resistance arteriole, and microvascular arteriolar endothelial function, respectively. We also assessed the conduit artery stiffness (pulse wave velocity and augmentation index) and measured the plasma concentrations of 92 cardiovascular disease biomarkers at baseline and after the clamp. RESULTS Postabsorptive and postprandial endothelial function was similar in controls and METSYN in all tested vessels. METSYN subjects were metabolically insulin resistant (P < .005). In controls, but not METSYN subjects, during euglycemic hyperinsulinemia, endothelial function improved at each level of arterial vasculature (P < .05 or less for each). Conduit vessel stiffness (pulse wave velocity) was increased in the METSYN group. Twelve of 92 biomarkers differed at baseline (P < .001) and remained different at the end of the insulin clamp. CONCLUSIONS We conclude that insulin enhances arterial endothelial function in health but not in METSYN, and this vascular insulin resistance may underlie its increased cardiovascular disease risk.
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Affiliation(s)
- Linda A Jahn
- Departments of Medicine (L.A.J., L.H., N.R., B.L., J.J.K., K.A., E.J.B.) and Pharmacology (E.J.B.), University of Virginia School of Medicine, Charlottesville, Virginia 22908; Department of Molecular and Clinical Medicine (L.-M.G., H.U.W.), Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, SE-413 45 Gothenburg, Sweden; and CVMD iMED (L.-M.G.), Department of Research and Development, AstraZeneca, 431 83 Mölndal, Sweden
| | - Lee Hartline
- Departments of Medicine (L.A.J., L.H., N.R., B.L., J.J.K., K.A., E.J.B.) and Pharmacology (E.J.B.), University of Virginia School of Medicine, Charlottesville, Virginia 22908; Department of Molecular and Clinical Medicine (L.-M.G., H.U.W.), Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, SE-413 45 Gothenburg, Sweden; and CVMD iMED (L.-M.G.), Department of Research and Development, AstraZeneca, 431 83 Mölndal, Sweden
| | - Nagashree Rao
- Departments of Medicine (L.A.J., L.H., N.R., B.L., J.J.K., K.A., E.J.B.) and Pharmacology (E.J.B.), University of Virginia School of Medicine, Charlottesville, Virginia 22908; Department of Molecular and Clinical Medicine (L.-M.G., H.U.W.), Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, SE-413 45 Gothenburg, Sweden; and CVMD iMED (L.-M.G.), Department of Research and Development, AstraZeneca, 431 83 Mölndal, Sweden
| | - Brent Logan
- Departments of Medicine (L.A.J., L.H., N.R., B.L., J.J.K., K.A., E.J.B.) and Pharmacology (E.J.B.), University of Virginia School of Medicine, Charlottesville, Virginia 22908; Department of Molecular and Clinical Medicine (L.-M.G., H.U.W.), Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, SE-413 45 Gothenburg, Sweden; and CVMD iMED (L.-M.G.), Department of Research and Development, AstraZeneca, 431 83 Mölndal, Sweden
| | - Justin J Kim
- Departments of Medicine (L.A.J., L.H., N.R., B.L., J.J.K., K.A., E.J.B.) and Pharmacology (E.J.B.), University of Virginia School of Medicine, Charlottesville, Virginia 22908; Department of Molecular and Clinical Medicine (L.-M.G., H.U.W.), Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, SE-413 45 Gothenburg, Sweden; and CVMD iMED (L.-M.G.), Department of Research and Development, AstraZeneca, 431 83 Mölndal, Sweden
| | - Kevin Aylor
- Departments of Medicine (L.A.J., L.H., N.R., B.L., J.J.K., K.A., E.J.B.) and Pharmacology (E.J.B.), University of Virginia School of Medicine, Charlottesville, Virginia 22908; Department of Molecular and Clinical Medicine (L.-M.G., H.U.W.), Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, SE-413 45 Gothenburg, Sweden; and CVMD iMED (L.-M.G.), Department of Research and Development, AstraZeneca, 431 83 Mölndal, Sweden
| | - Li-Ming Gan
- Departments of Medicine (L.A.J., L.H., N.R., B.L., J.J.K., K.A., E.J.B.) and Pharmacology (E.J.B.), University of Virginia School of Medicine, Charlottesville, Virginia 22908; Department of Molecular and Clinical Medicine (L.-M.G., H.U.W.), Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, SE-413 45 Gothenburg, Sweden; and CVMD iMED (L.-M.G.), Department of Research and Development, AstraZeneca, 431 83 Mölndal, Sweden
| | - Helena U Westergren
- Departments of Medicine (L.A.J., L.H., N.R., B.L., J.J.K., K.A., E.J.B.) and Pharmacology (E.J.B.), University of Virginia School of Medicine, Charlottesville, Virginia 22908; Department of Molecular and Clinical Medicine (L.-M.G., H.U.W.), Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, SE-413 45 Gothenburg, Sweden; and CVMD iMED (L.-M.G.), Department of Research and Development, AstraZeneca, 431 83 Mölndal, Sweden
| | - Eugene J Barrett
- Departments of Medicine (L.A.J., L.H., N.R., B.L., J.J.K., K.A., E.J.B.) and Pharmacology (E.J.B.), University of Virginia School of Medicine, Charlottesville, Virginia 22908; Department of Molecular and Clinical Medicine (L.-M.G., H.U.W.), Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, SE-413 45 Gothenburg, Sweden; and CVMD iMED (L.-M.G.), Department of Research and Development, AstraZeneca, 431 83 Mölndal, Sweden
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14
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Molecular Pathways Regulating Macrovascular Pathology and Vascular Smooth Muscle Cells Phenotype in Type 2 Diabetes. Int J Mol Sci 2015; 16:24353-68. [PMID: 26473856 PMCID: PMC4632754 DOI: 10.3390/ijms161024353] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 09/21/2015] [Accepted: 10/08/2015] [Indexed: 12/30/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) is a disease reaching a pandemic proportion in developed countries and a major risk factor for almost all cardiovascular diseases and their adverse clinical manifestations. T2DM leads to several macrovascular and microvascular alterations that influence the progression of cardiovascular diseases. Vascular smooth muscle cells (VSMCs) are fundamental players in macrovascular alterations of T2DM patients. VSMCs display phenotypic and functional alterations that reflect an altered intracellular biomolecular scenario of great vessels of T2DM patients. Hyperglycemia itself and through intraparietal accumulation of advanced glycation-end products (AGEs) activate different pathways, in particular nuclear factor-κB and MAPKs, while insulin and insulin growth-factor receptors (IGFR) are implicated in the activation of Akt and extracellular-signal-regulated kinases (ERK) 1/2. Nuclear factor-κB is also responsible of increased susceptibility of VSMCs to pro-apoptotic stimuli. Down-regulation of insulin growth-factor 1 receptors (IGFR-1R) activity in diabetic vessels also influences negatively miR-133a levels, so increasing apoptotic susceptibility of VSMCs. Alterations of those bimolecular pathways and related genes associate to the prevalence of a synthetic phenotype of VSMCs induces extracellular matrix alterations of great vessels. A better knowledge of those biomolecular pathways and related genes in VSMCs will help to understand the mechanisms leading to macrovascular alterations in T2DM patients and to suggest new targeted therapies.
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15
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Miki H, Takagi M. Design of serum-free medium for suspension culture of CHO cells on the basis of general commercial media. Cytotechnology 2014; 67:689-97. [PMID: 25149286 DOI: 10.1007/s10616-014-9778-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Accepted: 07/31/2014] [Indexed: 01/14/2023] Open
Abstract
The design of serum-free media for suspension culture of genetically engineered Chinese hamster ovary (CHO) cells using general commercial media as a basis was investigated. Subcultivation using a commercial serum-free medium containing insulin-like growth factor (IGF)-1 with or without FCS necessitated additives other than IGF-1 to compensate for the lack of FCS and improve cell growth. Suspension culture with media containing several combinations of growth factors suggested the effectiveness of addition of both IGF-1 and the lipid signaling molecule lysophosphatidic acid (LPA) for promoting cell growth. Subcultivation of CHO cells in suspension culture using the commercial serum-free medium EX-CELL™302, which contained an IGF-1 analog, supplemented with LPA resulted in gradually increasing specific growth rate comparable to the serum-containing medium and in almost the same high antibody production regardless of the number of generations. The culture with EX-CELL™302 supplemented with LPA in a jar fermentor with pH control at 6.9 showed an apparently higher cell growth rate than the cultures without pH control and with pH control at 6.8. The cell growth in the medium supplemented with aurintricarboxylic acid (ATA), which was much cheaper than IGF-1, in combination with LPA was synergistically promoted similarly to that in the medium supplemented with IGF-1 and LPA. In conclusion, the serum-free medium designed on the basis of general commercial media could support the growth of CHO cells and antibody production comparable to serum-containing medium in suspension culture. Moreover, the possibility of cost reduction by the substitution of IGF-1 with ATA was also shown.
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Affiliation(s)
- Hideo Miki
- Advanced Medical Research Laboratories, Research Division, Mitsubishi Tanabe Pharma Corporation, 1000 Kamoshida-cho, Aoba-ku, Yokohama, Kanagawa, 227-0033, Japan,
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16
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Moruzzi N, Del Sole M, Fato R, Gerdes JM, Berggren PO, Bergamini C, Brismar K. Short and prolonged exposure to hyperglycaemia in human fibroblasts and endothelial cells: metabolic and osmotic effects. Int J Biochem Cell Biol 2014; 53:66-76. [PMID: 24814290 DOI: 10.1016/j.biocel.2014.04.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 04/25/2014] [Accepted: 04/29/2014] [Indexed: 11/25/2022]
Abstract
High blood glucose levels are the main feature of diabetes. However, the underlying mechanism linking high glucose concentration to diabetic complications is still not fully elucidated, particularly with regard to human physiology. Excess of glucose is likely to trigger a metabolic response depending on the cell features, activating deleterious pathways involved in the complications of diabetes. In this study, we aim to elucidate how acute and prolonged hyperglycaemia alters the biology and metabolism in human fibroblasts and endothelial cells. We found that hyperglycaemia triggers a metabolic switch from oxidative phosphorylation to glycolysis that is maintained over prolonged time. Moreover, osmotic pressure is a major factor in the early metabolic response, decreasing both mitochondrial transmembrane potential and cellular proliferation. After prolonged exposure to hyperglycaemia we observed decreased mitochondrial steady-state and uncoupled respiration, together with a reduced ATP/ADP ratio. At the same time, we could not detect major changes in mitochondrial transmembrane potential and reactive oxygen species. We suggest that the physiological and metabolic alterations observed in healthy human primary fibroblasts and endothelial cells are an adaptive response to hyperglycaemia. The severity of metabolic and bioenergetics impairment associated with diabetic complications may occur after longer glucose exposure or due to interactions with cell types more sensitive to hyperglycaemia.
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Affiliation(s)
- Noah Moruzzi
- The Rolf Luft Research Center, Department of Endocrinology, Metabolism and Diabetes, Karolinska University/Hospital, 17176 Stockholm, Sweden.
| | - Marianna Del Sole
- The Rolf Luft Research Center, Department of Endocrinology, Metabolism and Diabetes, Karolinska University/Hospital, 17176 Stockholm, Sweden
| | - Romana Fato
- Department of Pharmacology and Biotechnology (FaBiT), University of Bologna, 40126 Bologna, Italy
| | - Jantje M Gerdes
- The Rolf Luft Research Center, Department of Endocrinology, Metabolism and Diabetes, Karolinska University/Hospital, 17176 Stockholm, Sweden; Institute for Diabetes and Regeneration Research, Helmholtz Zentrum München, Parkring 11, 85748 Garching, Germany
| | - Per-Olof Berggren
- The Rolf Luft Research Center, Department of Endocrinology, Metabolism and Diabetes, Karolinska University/Hospital, 17176 Stockholm, Sweden
| | - Christian Bergamini
- Department of Pharmacology and Biotechnology (FaBiT), University of Bologna, 40126 Bologna, Italy
| | - Kerstin Brismar
- The Rolf Luft Research Center, Department of Endocrinology, Metabolism and Diabetes, Karolinska University/Hospital, 17176 Stockholm, Sweden
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17
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Blumensatt M, Wronkowitz N, Wiza C, Cramer A, Mueller H, Rabelink MJ, Hoeben RC, Eckel J, Sell H, Ouwens DM. Adipocyte-derived factors impair insulin signaling in differentiated human vascular smooth muscle cells via the upregulation of miR-143. Biochim Biophys Acta Mol Basis Dis 2013; 1842:275-83. [PMID: 24333576 DOI: 10.1016/j.bbadis.2013.12.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 11/15/2013] [Accepted: 12/02/2013] [Indexed: 02/08/2023]
Abstract
Cardiovascular complications are common in patients with type 2 diabetes. Adipokines have been implicated in the induction of proliferative and pro-atherogenic alterations in human vascular smooth muscle cells (hVSMC). Other reports demonstrated the importance of the miRNA cluster miR-143/145 in the regulation of VSMC homeostasis and insulin sensitivity. Here we investigated whether the detrimental effects of adipokines on hVSMC function could be ascribed to alterations in miR-143/145 expression. The exposure of hVSMC to conditioned media (CM) from primary human subcutaneous adipocytes increased the expression of smooth muscle α-actin (SMA), and the miR-143/145 cluster, but markedly impaired the insulin-mediated phosphorylation of Akt and its substrate endothelial nitric oxide synthase (eNOS). Furthermore, CM promoted the phosphorylation of SMAD2 and p38, which have both been linked to miR-143/145 induction. Accordingly, the induction of miR-143/145 as well as the inhibition of insulin-mediated Akt- and eNOS-phosphorylation was prevented when hVSMC were treated with pharmacological inhibitors for Alk-4/5/7 and p38 before the addition of CM. The transfection of hVSMC with precursor miR-143, but not with precursor miR-145, resulted in impaired insulin-mediated phosphorylation of Akt and eNOS. This inhibition of insulin signaling by CM and miR-143 is associated with a reduction in the expression of the oxysterol-binding protein-related protein 8 (ORP8). Finally, the knock-down of ORP8 resulted in impaired insulin-mediated phosphorylation of Akt in hVSMC. Thus, the detrimental effects of adipocyte-derived conditioned media on insulin action in primary hVSMC can be ascribed to the Alk- and p38-dependent induction of miR-143 and subsequent downregulation of ORP8.
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MESH Headings
- Adipocytes/cytology
- Adipocytes/metabolism
- Adult
- Blotting, Western
- Cell Differentiation/drug effects
- Cells, Cultured
- Culture Media, Conditioned/metabolism
- Culture Media, Conditioned/pharmacology
- Female
- HEK293 Cells
- Humans
- Insulin/metabolism
- Insulin/pharmacology
- MicroRNAs/genetics
- Middle Aged
- Muscle, Smooth, Vascular/cytology
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Phosphorylation/drug effects
- RNA Interference
- Receptors, Steroid/genetics
- Receptors, Steroid/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Signal Transduction/drug effects
- Smad2 Protein/genetics
- Smad2 Protein/metabolism
- Up-Regulation/drug effects
- p38 Mitogen-Activated Protein Kinases/genetics
- p38 Mitogen-Activated Protein Kinases/metabolism
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Affiliation(s)
- Marcel Blumensatt
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center, Duesseldorf, Germany
| | - Nina Wronkowitz
- Paul-Langerhans-Group for Integrative Physiology, German Diabetes Center, Duesseldorf, Germany
| | - Claudia Wiza
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center, Duesseldorf, Germany
| | - Andrea Cramer
- Paul-Langerhans-Group for Integrative Physiology, German Diabetes Center, Duesseldorf, Germany
| | - Heidi Mueller
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center, Duesseldorf, Germany
| | - Martijn J Rabelink
- Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Rob C Hoeben
- Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Juergen Eckel
- Paul-Langerhans-Group for Integrative Physiology, German Diabetes Center, Duesseldorf, Germany
| | - Henrike Sell
- Paul-Langerhans-Group for Integrative Physiology, German Diabetes Center, Duesseldorf, Germany
| | - D Margriet Ouwens
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center, Duesseldorf, Germany; Department of Endocrinology, Ghent University Hospital, Ghent, Belgium.
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18
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Gallagher EJ, Alikhani N, Tobin-Hess A, Blank J, Buffin NJ, Zelenko Z, Tennagels N, Werner U, LeRoith D. Insulin receptor phosphorylation by endogenous insulin or the insulin analog AspB10 promotes mammary tumor growth independent of the IGF-I receptor. Diabetes 2013; 62:3553-60. [PMID: 23835331 PMCID: PMC3781483 DOI: 10.2337/db13-0249] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Endogenous hyperinsulinemia and insulin receptor (IR)/IGF-I receptor (IGF-IR) phosphorylation in tumors are associated with a worse prognosis in women with breast cancer. In vitro, insulin stimulation of the IR increases proliferation of breast cancer cells. However, in vivo studies demonstrating that IR activation increases tumor growth, independently of IGF-IR activation, are lacking. We hypothesized that endogenous hyperinsulinemia increases mammary tumor growth by directly activating the IR rather than the IGF-IR or hybrid receptors. We aimed to determine whether stimulating the IR with the insulin analog AspB10 could increase tumor growth independently of IGF-IR signaling. We induced orthotopic mammary tumors in control FVB/n and hyperinsulinemic MKR mice, and treated them with the insulin analog AspB10, recombinant human IGF-I, or vehicle. Tumors from mice with endogenous hyperinsulinemia were larger and had greater IR phosphorylation, but not IGF-IR phosphorylation, than those from control mice. Chronic AspB10 administration also increased tumor growth and IR (but not IGF-IR) phosphorylation in tumors. IGF-I led to activation of both the IGF-IR and IR and probably hybrid receptors. Our results demonstrate that IR phosphorylation increases tumor growth, independently of IGF-IR/hybrid receptor phosphorylation, and warrant consideration when developing therapeutics targeting the IGF-IR, but not the IR.
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Affiliation(s)
- Emily Jane Gallagher
- Division of Endocrinology, Diabetes and Bone Diseases, Samuel Bronfman Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Nyosha Alikhani
- Division of Endocrinology, Diabetes and Bone Diseases, Samuel Bronfman Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Aviva Tobin-Hess
- Division of Endocrinology, Diabetes and Bone Diseases, Samuel Bronfman Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Jeffrey Blank
- Division of Endocrinology, Diabetes and Bone Diseases, Samuel Bronfman Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Nicholas J. Buffin
- Division of Endocrinology, Diabetes and Bone Diseases, Samuel Bronfman Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Zara Zelenko
- Division of Endocrinology, Diabetes and Bone Diseases, Samuel Bronfman Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Norbert Tennagels
- R&D Diabetes Division, Sanofi-Aventis Deutschland, Frankfurt am Main, Germany
| | - Ulrich Werner
- R&D Diabetes Division, Sanofi-Aventis Deutschland, Frankfurt am Main, Germany
| | - Derek LeRoith
- Division of Endocrinology, Diabetes and Bone Diseases, Samuel Bronfman Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York
- Corresponding author: Derek LeRoith,
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Wu M, Obara Y, Norota I, Nagasawa Y, Ishii K. Insulin suppresses IKs (KCNQ1/KCNE1) currents, which require β-subunit KCNE1. Pflugers Arch 2013; 466:937-46. [PMID: 24068254 DOI: 10.1007/s00424-013-1352-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Revised: 09/06/2013] [Accepted: 09/07/2013] [Indexed: 11/29/2022]
Abstract
Abnormal QT prolongation in diabetic patients has become a clinical problem because it increases the risk of lethal ventricular arrhythmia. In an animal model of type 1 diabetes mellitus, several ion currents, including the slowly activating delayed rectifier potassium current (IKs), are altered. The IKs channel is composed of KCNQ1 and KCNE1 subunits, whose genetic mutations are well known to cause long QT syndrome. Although insulin is known to affect many physiological and pathophysiological events in the heart, acute effects of insulin on cardiac ion channels are poorly understood at present. This study was designed to investigate direct electrophysiological effects of insulin on IKs (KCNQ1/KCNE1) currents. KCNQ1 and KCNE1 were co-expressed in Xenopus oocytes, and whole cell currents were measured by a two-microelectrode voltage-clamp method. Acute application of insulin suppressed the KCNQ1/KCNE1 currents and phosphorylated Akt and extracellular signal-regulated kinase (ERK), the two major downstream effectors, in a concentration-dependent manner. Wortmannin (10(-6) M), a phosphoinositide 3-kinase (PI3K) inhibitor, attenuated the suppression of the currents and phosphorylation of Akt by insulin, whereas U0126 (10(-5) M), a mitogen-activated protein kinase kinase (MEK) inhibitor, had no effect on insulin-induced suppression of the currents. In addition, insulin had little effect on KCNQ1 currents without KCNE1, which indicated an essential role of KCNE1 in the acute suppressive effects of insulin. Mutagenesis studies revealed amino acid residues 111-118 within the distal third C-terminus of KCNE1 as an important region. Insulin has direct electrophysiological effects on IKs currents, which may affect cardiac excitability.
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Affiliation(s)
- Minghua Wu
- Department of Pharmacology, Yamagata University School of Medicine, 2-2-2 Iida-nishi, Yamagata, 990-9585, Japan
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20
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Kou X, Han Y, Yang D, Liu Y, Fu J, Zheng S, He D, Zhou L, Zeng C. Dopamine d(1)-like receptors suppress proliferation of vascular smooth muscle cell induced by insulin-like growth factor-1. Clin Exp Hypertens 2013; 36:140-7. [PMID: 23713966 DOI: 10.3109/10641963.2013.789048] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE Proliferation of vascular smooth muscle cells (VSMCs) participates in the pathogenesis and development of cardiovascular diseases, including essential hypertension and atherosclerosis. Our previous study found that stimulation of D1-like dopamine receptors inhibited insulin-induced proliferation of VSMCs. Insulin-like growth factor-1 (IGF-1) and insulin share similar structure and biological effect. However, whether or not there is any effect of D1-like receptors on IGF-1-induced proliferation of VSMCs is not known. Therefore, we investigated the inhibitory effect of D1-like dopamine receptors on the IGF-1-induced VSMCs proliferation in this study. METHOD VSMC proliferation was determined by [(3)H]-thymidine incorporation, the uptake of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and cell number. Phosphorylated/non-phosphorylated IGF-1 receptor, Akt, mTOR and p70S6K expressions were determined by immunoblotting. The oligodeoxynucleotides were transfected to A10 cells to identify the effect of D1 and D5 receptors, respectively. RESULTS IGF-1 increased the proliferation of VSMCs, while in the presence of fenoldopam, IGF-1-mediated stimulatory effect was reduced. Use of either antisense for D1 or D5 receptor partially inhibited the fenoldopam-induced antiproliferation effect of VSMCs. Use of both D1 and D5 receptor antisenses completely blocked the inhibitory effect of fenoldopam. In the presence of PI3k and mTOR inhibitors, the IGF-1-mediated proliferation of VSMCs was blocked. Moreover, IGF-1 increased the phosphorylation of PI3k and mTOR. The inhibitory effect of fenoldopam on VSMC proliferation might be due to the inhibition of IGF-1 receptor expression and IGF-1 phosphorylation, because in the presence of fenoldopam, the stimulatory effect of IGF-1 on phosphorylation of IGF-1 receptor, PI3k and mTOR is reduced, the IGF-1 receptor expression was reduced in A10 cells. CONCLUSION Activation of the D1-like receptors suppressed the proliferative effect of IGF-1 in A10 cells via the inhibition of the IGF-1R/Akt/mTOR/p70S6K pathway and downregulated the expression of IGF-1 receptor.
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Affiliation(s)
- Xun Kou
- Department of Cardiology, Daping Hospital, The Third Military Medical University , Chongqing , P.R. China and
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Woods TC. Dysregulation of the Mammalian Target of Rapamycin and p27Kip1 Promotes Intimal Hyperplasia in Diabetes Mellitus. Pharmaceuticals (Basel) 2013; 6:716-27. [PMID: 24276258 PMCID: PMC3816729 DOI: 10.3390/ph6060716] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 05/01/2013] [Accepted: 05/08/2013] [Indexed: 01/19/2023] Open
Abstract
The proliferation and migration of vascular smooth muscle cells (VSMCs) in the intima of an artery, known as intimal hyperplasia, is an important component of cardiovascular diseases. This is seen most clearly in the case of in-stent restenosis, where drug eluting stents are used to deliver agents that prevent VSMC proliferation and migration. One class of agents that are highly effective in the prevention of in-stent restenosis is the mammalian Target of Rapamycin (mTOR) inhibitors. Inhibition of mTOR blocks protein synthesis, cell cycle progression, and cell migration. Key to the effects on cell cycle progression and cell migration is the inhibition of mTOR-mediated degradation of p27Kip1 protein. p27Kip1 is a cyclin dependent kinase inhibitor that is elevated in quiescent VSMCs and inhibits the G1 to S phase transition and cell migration. Under normal conditions, vascular injury promotes degradation of p27Kip1 protein in an mTOR dependent manner. Recent reports from our lab suggest that in the presence of diabetes mellitus, elevation of extracellular signal response kinase activity may promote decreased p27Kip1 mRNA and produce a relative resistance to mTOR inhibition. Here we review these findings and their relevance to designing treatments for cardiovascular disease in the presence of diabetes mellitus.
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Affiliation(s)
- Thomas Cooper Woods
- Tulane Heart and Vascular Institute and the Department of Physiology, School of Medicine, Tulane University, 1430 Tulane Avenue, SL-48, New Orleans, LA 70112, USA.
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Comerford KB, Almario RU, Kim K, Karakas SE. Lean mass and insulin resistance in women with polycystic ovary syndrome. Metabolism 2012; 61:1256-60. [PMID: 22424820 DOI: 10.1016/j.metabol.2012.02.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2011] [Revised: 02/04/2012] [Accepted: 02/06/2012] [Indexed: 10/28/2022]
Abstract
Insulin resistance is common in women with polycystic ovary syndrome (PCOS). Muscle is the major tissue utilizing glucose while excess adipose tissue relates to insulin resistance. Thus, body composition is likely to be an important regulator of insulin sensitivity. Thirty-nine PCOS patients (age: 29.9±1.0 years; BMI: 33.8±1.2 kg/m(2)) participated in a cross sectional study. Body composition was measured by dual energy x-ray absorptiometry (DEXA). Insulin resistance and secretion were assessed using oral glucose tolerance test (OGTT) and frequently sampled intravenous glucose tolerance test (FS-IVGTT). In contrast with the conventional expectations, lean mass correlated directly (P<.05) with the insulin resistance measure HOMA (r=0.440); and inversely with the insulin sensitivity index QUICKI (r=-0.522) independent of fat mass. In 11 pairs of subjects matched for fat mass (35.6±2.2 and 35.6±2.4 kg) but with discordant lean mass (52.8±1.8 vs 44.4±1.6 kg), those with higher lean mass had a higher glucose response during OGTT (AUC(Glucose); P=.034). In contrast, 17 pairs matched for lean mass (48.7±1.7 and 48.9±1.6 kg) but discordant for fat mass (43.3±2.6 vs 30.3±8.9 kg) showed no differences in insulin resistance parameters. These novel findings indicate that lean mass relates directly to insulin resistance in PCOS.
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Affiliation(s)
- Kevin B Comerford
- Nutritional Biology Graduate Group, Department of Nutrition, The University of California at Davis, Davis, California, USA
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Sonntag WE, Csiszar A, deCabo R, Ferrucci L, Ungvari Z. Diverse roles of growth hormone and insulin-like growth factor-1 in mammalian aging: progress and controversies. J Gerontol A Biol Sci Med Sci 2012; 67:587-98. [PMID: 22522510 DOI: 10.1093/gerona/gls115] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Because the initial reports demonstrating that circulating growth hormone and insulin-like growth factor-1 decrease with age in laboratory animals and humans, there have been numerous studies related to the importance of these hormones for healthy aging. Nevertheless, the role of these potent anabolic hormones in the genesis of the aging phenotype remains controversial. In this chapter, we review the studies demonstrating the beneficial and deleterious effects of growth hormone and insulin-like growth factor-1 deficiency and explore their effects on specific tissues and pathology as well as their potentially unique effects early during development. Based on this review, we conclude that the perceived contradictory roles of growth hormone and insulin-like growth factor-1 in the genesis of the aging phenotype should not be interpreted as a controversy on whether growth hormone or insulin-like growth factor-1 increases or decreases life span but rather as an opportunity to explore the complex roles of these hormones during specific stages of the life span.
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Affiliation(s)
- William E Sonntag
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Stanton L. Young Biomedical Research Center 1303, 975 NE 10th Street, Oklahoma City, OK 74104, USA.
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Sherajee SJ, Fujita Y, Rafiq K, Nakano D, Mori H, Masaki T, Hara T, Kohno M, Nishiyama A, Hitomi H. Aldosterone induces vascular insulin resistance by increasing insulin-like growth factor-1 receptor and hybrid receptor. Arterioscler Thromb Vasc Biol 2011; 32:257-63. [PMID: 22173225 DOI: 10.1161/atvbaha.111.240697] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
OBJECTIVE We previously showed that aldosterone induces insulin resistance in rat vascular smooth muscle cells (VSMCs). Because insulin-like growth factor-1 receptor (IGF1R) affects insulin signaling, we hypothesized that aldosterone induces vascular insulin resistance and remodeling via upregulation of IGF1R and its hybrid insulin/insulin-like growth factor-1 receptor. METHODS AND RESULTS Hybrid receptor expression was measured by immunoprecipitation. Hypertrophy of VSMCs was evaluated by (3)H-labeled leucine incorporation. Aldosterone (10 nmol/L) significantly increased protein and mRNA expression of IGF1R and hybrid receptor in VSMCs but did not affect insulin receptor expression. Mineralocorticoid receptor blockade with eplerenone inhibited aldosterone-induced increases in IGF1R and hybrid receptor. Aldosterone augmented insulin (100 nmol/L)-induced extracellular signal-regulated kinase 1/2 phosphorylation. Insulin-induced leucine incorporation and α-smooth muscle actin expression were also augmented by aldosterone in VSMCs. These aldosterone-induced changes were significantly attenuated by eplerenone or picropodophyllin, an IGF1R inhibitor. Chronic infusion of aldosterone (0.75 μg/hour) increased blood pressure and aggravated glucose metabolism in rats. Expression of hybrid receptor, azan-positive area, and oxidative stress in aorta was increased in aldosterone-infused rats. Spironolactone and tempol prevented these aldosterone-induced changes. CONCLUSIONS Aldosterone induces vascular remodeling through IGF1R- and hybrid receptor-dependent vascular insulin resistance. Mineralocorticoid receptor blockade may attenuate angiopathy in hypertensive patients with hyperinsulinemia.
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Affiliation(s)
- Shamshad J Sherajee
- Department of Pharmacology, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan
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Jiang Q, Ko WKW, Wong AOL. Insulin-like growth factor as a novel stimulator for somatolactin secretion and synthesis in carp pituitary cells via activation of MAPK cascades. Am J Physiol Endocrinol Metab 2011; 301:E1208-19. [PMID: 21862722 DOI: 10.1152/ajpendo.00347.2011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Somatolactin (SL), a member of the growth hormone/prolactin family, is a pituitary hormone unique to fish models. Although SL is known to have diverse functions in fish, the mechanisms regulating its secretion and synthesis have not been fully characterized. Using grass carp pituitary cells as a model, here we examined the role of insulin-like growth factor (IGF) in SL regulation at the pituitary level. As a first step, the antisera for the two SL isoforms expressed in the carp pituitary, SLα and SLβ, were produced, and their specificity was confirmed by antiserum preabsorption and immunohistochemical staining in the carp pituitary. Western blot using these antisera revealed that grass carp SLα and SLβ could be N-linked glycosylated and their basal secretion and cell content in carp pituitary cells could be elevated by IGF-I and -II treatment. These stimulatory effects occurred with parallel rises in SLα and SLβ mRNA levels, and these SL gene expression responses were not mimicked by insulin but blocked by IGF-I receptor inactivation. In carp pituitary cells, IGF-I and -II could induce rapid phosphorylation of IGF-I receptor, MEK1/2, ERK1/2, MKK3/6, and p38 MAPK; and SLα and SLβ secretion, protein production, and mRNA expression caused by IGF-I and -II stimulation were negated by inactivating MEK1/2 and p38 MAPK. Parallel inhibition of PI3K and Akt, however, were not effective in these regards. These results, taken together, provide evidence that IGF can upregulate SL secretion and synthesis at the pituitary level via stimulation of MAPK- but not PI3K/Akt-dependent pathways.
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Affiliation(s)
- Quan Jiang
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
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26
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Bornfeldt KE, Tabas I. Insulin resistance, hyperglycemia, and atherosclerosis. Cell Metab 2011; 14:575-85. [PMID: 22055501 PMCID: PMC3217209 DOI: 10.1016/j.cmet.2011.07.015] [Citation(s) in RCA: 544] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 07/13/2011] [Accepted: 07/27/2011] [Indexed: 12/16/2022]
Abstract
Progress in preventing atherosclerotic coronary artery disease (CAD) has been stalled by the epidemic of type 2 diabetes. Further advances in this area demand a thorough understanding of how two major features of type 2 diabetes, insulin resistance and hyperglycemia, impact atherosclerosis. Insulin resistance is associated with systemic CAD risk factors, but increasing evidence suggests that defective insulin signaling in atherosclerotic lesional cells also plays an important role. The role of hyperglycemia in CAD associated with type 2 diabetes is less clear. Understanding the mechanisms whereby type 2 diabetes exacerbates CAD offers hope for new therapeutic strategies to prevent and treat atherosclerotic vascular disease.
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Affiliation(s)
- Karin E Bornfeldt
- Department of Pathology, Diabetes and Obesity Center of Excellence, 815 Mercer Street, University of Washington, Seattle, WA 98109, USA
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27
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Engineered insulin-like growth factor-1 for improved smooth muscle regeneration. Biomaterials 2011; 33:494-503. [PMID: 22014943 DOI: 10.1016/j.biomaterials.2011.09.088] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 09/27/2011] [Indexed: 02/05/2023]
Abstract
Insulin-like growth factor-1 (IGF-1) has been shown to induce potent mitogenic responses in various cell types, yet its sustained local delivery is still an underdeveloped domain in the clinic. We report here an engineered IGF-1 that facilitates extended local delivery to a site through its immobilization capacity within fibrin. Through recombinant fusion with a substrate sequence tag derived from α(2)-plasmin inhibitor (α(2)PI(1-8)), the resulting variant, α(2)PI(1-8)-IGF-1, was covalently incorporated into fibrin matrices during normal thrombin/factor XIIIa-mediated polymerization. Bioactivity of the variant was confirmed to be equivalent to wild type (WT) IGF-1 via IGF-1 receptor phosphorylation and cell proliferation studies in urinary tract-derived cells in 2-D. Assessment of functional retention within 3-D fibrin matrices demonstrated that incorporation of α(2)PI(1-8)-IGF-1 induced a 1.3- and 1.5-fold more robust proliferative response in smooth muscle cells (SMCs) than WT IGF-1 and negative control matrices, respectively, when release was not contained. Sustained α(2)PI(1-8)-IGF-1 availability at bladder lesion sites in vivo evoked a considerable increase in SMC proliferation and a favorable host tissue response after 28 days in rats. We conclude that the sustained local IGF-1 availability from fibrin provided by our variant protein enhances smooth muscle regeneration better than the WT form of the protein.
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28
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Liu G, Hitomi H, Hosomi N, Lei B, Nakano D, Deguchi K, Mori H, Masaki T, Ma H, Griendling KK, Nishiyama A. Mechanical stretch augments insulin-induced vascular smooth muscle cell proliferation by insulin-like growth factor-1 receptor. Exp Cell Res 2011; 317:2420-8. [PMID: 21854769 DOI: 10.1016/j.yexcr.2011.07.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 06/29/2011] [Accepted: 07/16/2011] [Indexed: 11/16/2022]
Abstract
Insulin resistance and hypertension have been implicated in the pathogenesis of cardiovascular disease; however, little is known about the roles of insulin and mechanical force in vascular smooth muscle cell (VSMC) remodeling. We investigated the contribution of mechanical stretch to insulin-induced VSMC proliferation. Thymidine incorporation was stimulated by insulin in stretched VSMCs, but not in un-stretched VSMCs. Insulin increased 2-deoxy-glucose incorporation in both stretched and un-stretched VSMCs. Mechanical stretch augmented insulin-induced extracellular signal-regulated kinase (ERK) and Akt phosphorylation. Inhibitors of epidermal growth factor (EGF) receptor tyrosine kinase and Src attenuated insulin-induced ERK and Akt phosphorylation, as well as thymidine incorporation, whereas 2-deoxy-glucose incorporation was not affected by these inhibitors. Moreover, stretch augmented insulin-like growth factor (IGF)-1 receptor expression, although it did not alter the expression of insulin receptor and insulin receptor substrate-1. Insulin-induced ERK and Akt activation, and thymidine incorporation were inhibited by siRNA for the IGF-1 receptor. Mechanical stretch augments insulin-induced VSMC proliferation via upregulation of IGF-1 receptor, and downstream Src/EGF receptor-mediated ERK and Akt activation. Similar to in vitro experiment, IGF-1 receptor expression was also augmented in hypertensive rats. These results provide a basis for clarifying the molecular mechanisms of vascular remodeling in hypertensive patients with hyperinsulinemia.
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Affiliation(s)
- Gang Liu
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
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29
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Insulin-mediated upregulation of KCa3.1 channels promotes cell migration and proliferation in rat vascular smooth muscle. J Mol Cell Cardiol 2011; 51:51-7. [DOI: 10.1016/j.yjmcc.2011.03.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 03/07/2011] [Accepted: 03/26/2011] [Indexed: 12/29/2022]
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Growth hormone and prolactin regulate human neural stem cell regenerative activity. Neuroscience 2011; 190:409-27. [PMID: 21664953 DOI: 10.1016/j.neuroscience.2011.05.029] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 05/10/2011] [Accepted: 05/12/2011] [Indexed: 12/18/2022]
Abstract
We have previously shown that the growth hormone (GH)/prolactin (PRL) axis has a significant role in regulating neuroprotective and/or neurorestorative mechanisms in the brain and that these effects are mediated, at least partly, via actions on neural stem cells (NSCs). Here, using NSCs with properties of neurogenic radial glia derived from fetal human forebrains, we show that exogenously applied GH and PRL promote the proliferation of NSCs in the absence of epidermal growth factor or basic fibroblast growth factor. When applied to differentiating NSCs, they both induce neuronal progenitor proliferation, but only PRL has proliferative effects on glial progenitors. Both GH and PRL also promote NSC migration, particularly at higher concentrations. Since human GH activates both GH and PRL receptors, we hypothesized that at least some of these effects may be mediated via the latter. Migration studies using receptor-specific antagonists confirmed that GH signals via the PRL receptor promote migration. Mechanisms of receptor signaling in NSC proliferation, however, remain to be elucidated. In summary, GH and PRL have complex stimulatory and modulatory effects on NSC activity and as such may have a role in injury-related recovery processes in the brain.
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31
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Insulin-like growth factor I receptor β expression in hepatocellular carcinoma. Hum Pathol 2011; 42:882-91. [PMID: 21292299 DOI: 10.1016/j.humpath.2010.10.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 10/21/2010] [Accepted: 10/22/2010] [Indexed: 12/11/2022]
Abstract
The insulinlike growth factor signaling axis (factors I and II and their receptor) has been implicated in hepatocarcinogenesis. Previous studies on insulinlike growth factor I receptor using resected hepatocellular carcinoma generated mixed results; however, the distribution and clinical significance of insulinlike growth factor I receptor β expression in hepatocellular carcinoma in the setting of liver transplantation have not been evaluated. Immunohistochemical staining for insulinlike growth factor I receptor β was performed in 72 liver explants from patients with hepatocellular carcinoma undergoing liver transplantation. Expression of insulinlike growth factor I receptor β in hepatocytes was noted in 59.7% of tumors but only 6.9% of adjacent, nontumorous liver tissues (P < .001). Compared with subjects with tumors within Milan criteria, those who fell beyond had 3.1 times higher odds of having insulinlike growth factor I receptor β-positive tumors (95% confidence interval, 1.003-9.8). Poorly differentiated hepatocellular carcinomas had 10.3 times higher odds of insulinlike growth factor I receptor β positivity compared with well- or moderately differentiated tumors (95% confidence interval, 1.3-85.2). Subjects with nonalcoholic steatohepatitis were less likely to have insulinlike growth factor I receptor β-positive tumors (P = .015). Finally, higher arteriolar insulinlike growth factor I receptor β scores in the tumor and adjacent liver were significantly associated with insulinlike growth factor I receptor β expression in tumor cells (P = .015 and .043 for intratumoral and adjacent arterioles, respectively) in a subset of 26 randomly chosen hepatocellular carcinoma. Our results suggest that synchronized up-regulation of the insulinlike growth factor I receptor axis in tumor cells and intratumoral and adjacent arterioles could represent a mechanism of hepatocarcinogenesis and progression as manifest by poor differentiation and tumors beyond Milan criteria. Targeted therapies against insulinlike growth factor receptors may be justifiable in the treatment of hepatocellular carcinoma.
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Claassen H, Schicht M, Brandt J, Reuse K, Schädlich R, Goldring MB, Guddat SS, Thate A, Paulsen F. C-28/I2 and T/C-28a2 chondrocytes as well as human primary articular chondrocytes express sex hormone and insulin receptors--Useful cells in study of cartilage metabolism. Ann Anat 2010; 193:23-9. [PMID: 20971625 DOI: 10.1016/j.aanat.2010.09.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2010] [Revised: 09/10/2010] [Accepted: 09/17/2010] [Indexed: 11/29/2022]
Abstract
Sex hormones and insulin have been implicated in articular cartilage metabolism. To supplement previous findings on the regulation of matrix synthesis with 17β-estradiol and insulin and to find a possible model to study cartilage metabolism in vitro, we evaluated the expression of estrogen receptors α and β (ERα, ERβ), androgen receptor (AR) and insulin receptor (IR), in immortalized C-28/I2 and T/C-28a2 chondrocytes and in human primary articular cartilage cells. Chondrocytes were treated with increasing concentrations of 17β-estradiol, dihydrotestosterone or insulin and analyzed by means of RT-PCR and Western blotting. Both cell lines as well as human articular chondrocytes expressed ER α and β, AR and IR at mRNA and protein levels. In immortalized C-28/I2 chondrocytes, we showed that increasing concentrations of 17β-estradiol diminished the 95kDa band of IR. Since 17β-estradiol suppresses insulin-induced proline incorporation and type II collagen synthesis, as we have previously demonstrated, our findings give the first clue that 17β-estradiol may have negative effects on cartilage anabolism triggered by insulin during hormonal imbalance. Compared to chondrocytes cultured without hormones, immunostaining for ERα/β, AR and IR was decreased in both cell lines after incubation of cells with the receptor-specific hormones. It can be assumed that C-28/I2 and T/C-28a2 chondrocytes interact with the respective hormones. Our findings provide a reproducible model for investigating sex hormone and insulin receptors, which are present in low concentrations in articular chondrocytes, in the tissue-specific context of cartilage metabolism.
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Affiliation(s)
- Horst Claassen
- Institut für Anatomie und Zellbiologie, Martin-Luther-Universität Halle-Wittenberg, Große Steinstraße 52, D-06097 Halle (Saale), Germany.
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Insulin is a potent myeloma cell growth factor through insulin/IGF-1 hybrid receptor activation. Leukemia 2010; 24:1940-50. [PMID: 20844560 DOI: 10.1038/leu.2010.192] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Insulin and insulin growth factor type 1 (IGF-1) and their receptors are closely related molecules, but both factors bind to the receptor of the other one with a weak affinity. No study has presently documented a role of insulin as a myeloma growth factor (MGF) for human multiple myeloma cells (MMCs), whereas many studies have concluded that IGF-1 is a major MGF. IGF-1 receptor (IGF-1R) is aberrantly expressed by MMCs in association with a poor prognosis. In this study we show that insulin receptor (INSR) is increased throughout normal plasma cell differentiation. INSR gene is also expressed by MMCs of 203/206 newly diagnosed patients. Insulin is an MGF as potent as IGF-1 at physiological concentrations and requires the presence of insulin/IGF-1 hybrid receptors, stimulating INSR(+)IGF-1R(+) MMCs, unlike INSR(+)IGF-1R(-) or INSR(-)IGF-1R(-) MMCs. Immunoprecipitation experiments indicate that INSR is linked with IGF-1R in MMCs and that insulin induces both IGF-1R and INSR phosphorylations and vice versa. In conclusion, we demonstrate for the first time that insulin is an MGF as potent as IGF-1 at physiological concentrations and its activity necessitates insulin/IGF-1 hybrid receptor activation. Further therapeutic strategies targeting the IGF/IGF-1R pathway have to take into account neutralizing the IGF-1R-mediated insulin MGF activity.
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Costa SMR, Silva GAPD. The maternal intrauterine environment as a generator of children at risk of metabolic syndrome: a review. REVISTA BRASILEIRA DE SAÚDE MATERNO INFANTIL 2010. [DOI: 10.1590/s1519-38292010000300002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nowadays, scientists are paying special attention to the increasing prevalence of obesity and associated co-morbidities, especially metabolic syndrome. This is due to observation of the spread of this syndrome from one generation to another and the growing number of obese pregnant women, which seems to exacerbate this situation. It is not yet well established whether the pathophysiological process underlying metabolic syndrome, namely insulin resistance, is due to changes in the receptor or in the cascade of intracellular processes. This narrative review aims to report on physiological and pathological changes occurring in pregnancy and the presence of Insulin receptor, Insulin Growth Factor-I receptor and the hybrid receptor, focusing on the presence of hyperinsulinemia in the growth and development of fetuses susceptible to metabolic syndrome.
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Arabkhari M, Bunda S, Wang Y, Wang A, Pshezhetsky AV, Hinek A. Desialylation of insulin receptors and IGF-1 receptors by neuraminidase-1 controls the net proliferative response of L6 myoblasts to insulin. Glycobiology 2010; 20:603-16. [PMID: 20100694 DOI: 10.1093/glycob/cwq010] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We recently established that the subunit of cell surface-residing elastin receptor, neuraminidase-1 (Neu1), can desialylate adjacent insulin-like growth factor 1 receptors (IGF-1R) of arterial smooth muscle cells, thereby quenching their proliferative response to insulin-like growth factor II. In this study, we explored whether Neu1 would also desialylate the insulin receptors (IR), as well as the IGF-1R on rat skeletal L6 myoblasts, and whether desialylation of IR and IGF-1R would affect a net proliferative effect of insulin. First, we found that physiological (0.5-1 nM) and high therapeutic (10 nM) insulin concentrations induced a modest increase in proliferation rate of cultured L6 myoblasts. While IR kinase inhibitor could abolish the mitogenic effect of these insulin concentrations, the observed more pronounced proliferative response to supraphysiological concentration (100 nM) of insulin could be eliminated only by specific inhibition of IGF-1R. Then, we found that treatment of L6 cells with mouse-derived Neu1 or with Clostridium perfringens neuraminidase caused desialylation of IR, which coincided with a significant increase of their proliferative response to lower (0.5-10 nM) concentrations of insulin. In contrast, experimental desialylation of IGF-1R coincided with elimination of the heightened proliferative response of L6 myoblasts to 100 nM insulin. Importantly, we also found that inhibition of endogenous Neu1 abolished the increase in proliferation of L6 cells induced by 1 and 10 nM of insulin, but amplified the proliferative effect of 100 nM insulin. We therefore conclude that desialylation of both IR and IGF-1R by Neu1 controls the net proliferative response of skeletal myoblasts to insulin.
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Affiliation(s)
- Majid Arabkhari
- Physiology and Experimental Medicine Program, The Hospital for Sick Children, University of Toronto, Canada
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Christophidis LJ, Gorba T, Gustavsson M, Williams CE, Werther GA, Russo VC, Scheepens A. Growth hormone receptor immunoreactivity is increased in the subventricular zone of juvenile rat brain after focal ischemia: a potential role for growth hormone in injury-induced neurogenesis. Growth Horm IGF Res 2009; 19:497-506. [PMID: 19524466 DOI: 10.1016/j.ghir.2009.05.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2009] [Revised: 04/30/2009] [Accepted: 05/14/2009] [Indexed: 02/05/2023]
Abstract
BACKGROUND During recovery from an ischemic brain injury, a cerebral growth hormone (GH) axis is activated. Whilst GH has been demonstrated to be neuroprotective both in vitro and in vivo, a role for GH in neuro-restorative processes after brain injury has yet to be studied. OBJECTIVE To explore a role for GH in injury-induced neurogenesis by examining GH receptor (GH-R) immunoreactivity within the subventricular zone (SVZ) of juvenile rats after brain injury and by testing the proliferative capacity of GH on embryonic mouse neural stem cells. DESIGN Twenty-one day old rats were subjected to unilateral hypoxic-ischemia of the brain and sacrificed 1-15days later. Coronal brain sections from these animals and age-matched naïve controls were immunostained for GH-R and cell markers of neurogenesis. The level of GH-R immunoreactivity in the ipsilateral and contralateral SVZ of each animal was semi-quantified both by independent blinded scoring by two examiners and blinded image analysis. To examine the effect of GH on proliferation of embryonic mouse neural stem cells, cells were treated with increasing concentrations of rat pituitary GH for 48h in the presence of 5'-bromo-2'-deoxyuridine. RESULTS The level of GH-R immunoreactivity in the ipsilateral SVZ was significantly increased 5days after injury vs. the contralateral SVZ, coinciding both spatially and temporally with injury-induced neurogenesis. The population of GH-R immunopositive cells in the ipsilateral SVZ at this time was found to include proliferating cells (Ki67 immunopositive), neural progenitor cells (nestin immunopositive) and post-proliferative migratory neuroblasts (doublecortin immunopositive). Stimulation of embryonic mouse NSCs with physiological concentrations of rat pituitary GH elicited a dose-dependent proliferative response. CONCLUSION These results indicate a novel role for GH and its receptor in injury-induced neurogenesis, and suggest that GH treatment may potentiate endogenous neuro-restorative processes after brain injury.
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Abstract
Insulin is a vascular hormone, able to influence vascular cell responses. In this review, we consider the insulin actions on vascular endothelium and on vascular smooth muscle cells (VSMC) both in physiological conditions and in the presence of insulin resistance. In particular, we focus the relationships between activation of insulin signalling pathways of phosphatidylinositol-3 kinase (PI3-K) and mitogen-activated protein kinase (MAPK) and the different vascular actions of insulin, with a particular attention to the insulin ability to activate the pathway nitric oxide (NO)/cyclic GMP/PKG via PI3-K, owing to the peculiar relevance of NO in vascular biology. We also discuss the insulin actions mediated by the MAPK pathway (such as endothelin-1 synthesis and secretion and VSMC proliferation and migration) and by the interactions between the two pathways, both in insulin-sensitive and in insulin-resistant states. Finally, we consider the influence of free fatty acids, cytokines and endothelin on vascular insulin resistance.
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Affiliation(s)
- Giovanni Anfossi
- Internal Medicine University Unit, San Luigi Gonzaga Faculty of Medicine and Department of Clinical and Biological Sciences, Turin University, San Luigi Gonzaga Hospital, 10043 Orbassano, Turin, Italy
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Li G, Barrett EJ, Ko SH, Cao W, Liu Z. Insulin and insulin-like growth factor-I receptors differentially mediate insulin-stimulated adhesion molecule production by endothelial cells. Endocrinology 2009; 150:3475-82. [PMID: 19423756 PMCID: PMC2717867 DOI: 10.1210/en.2009-0172] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Patients with type 2 diabetes are hyperinsulinemic and insulin resistant and develop premature atherosclerosis. High concentrations of insulin stimulate the production of adhesion molecules by endothelial cells (ECs). ECs express abundant IGF-I receptors as well as insulin receptors. Whether IGF-I receptors contribute to insulin-induced endothelial production of adhesion molecules is unknown. Bovine aortic ECs (BAECs) were incubated with insulin (100 nm) for 24 h. The cellular content of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) was measured, and monocyte adhesion to ECs was quantified. Insulin increased both VCAM-1 (P < 0.001) and ICAM-1 (P < 0.0002) content, which was accompanied by an increased number of monocytes adherent to BAECs (P = 0.0001). Inhibition of either MAPK kinase-1 or p38 MAPK but not phosphatidylinositol 3-kinase abolished insulin-mediated production of adhesion molecules. Insulin receptor small interfering RNA knockdown abolished insulin-stimulated increases of ICAM-1 but not VCAM-1. Conversely, IGF-I receptor blockade with either a neutralizing antibody or specific small interfering RNA eliminated insulin-induced VCAM-1 but not ICAM-1 production. Blockade of signaling via either the insulin or IGF-I receptors decreased monocyte adherence to BAECs (P < 0.01 for each). We conclude that insulin and IGF-I receptors differentially mediate the production of adhesion molecules by ECs and monocyte adhesion onto the vascular endothelium in response to the hyperinsulinemic state. Dual-receptor activation may most effectively contribute to the pathogenesis of atherosclerotic disease in diabetes.
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Affiliation(s)
- Guolian Li
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Virginia Health System, Charlottesville, Virginia 22908-1410, USA
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D1-like receptors inhibit insulin-induced vascular smooth muscle cell proliferation via down-regulation of insulin receptor expression. J Hypertens 2009; 27:1033-41. [PMID: 19293728 DOI: 10.1097/hjh.0b013e3283293c7b] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Vascular smooth muscle cell (VSMC) proliferation is central to the development of vascular diseases, including hypertension, which is regulated by numerous hormones and humoral factors. Our previous study showed that the stimulatory effect of norepinephrine on VSMC proliferation is inhibited by D1-like receptors and the D3 dopamine receptor, a member of the D2-like receptor family. Insulin is a proliferative hormone but it is not known if there is any interaction between insulin and D1-like receptors. We hypothesized that Dl-like receptors may have an inhibitory effect on the insulin-induced VSMC proliferation; aberrant insulin and Dl-like receptor functions could be involved in the pathogenesis of essential hypertension. METHODS VSMC proliferation was determined by [H]-thymidine incorporation; insulin receptor mRNA and protein expressions were determined by RT-PCR, immunoblotting, and immunohistochemistry. RESULTS Insulin increased VSMC proliferation in immortalized aortic A10 cells, determined by [H]-thymidine incorporation. Although the D1-like receptor, by itself, had no effect on VSMC proliferation, stimulation with fenoldopam, a D1-like receptor agonist, inhibited the stimulatory effect of insulin. The inhibitory effect of fenoldopam on insulin-mediated VSMC proliferation was receptor specific, because its effect could be blocked by SCH23390, a D1-like receptor antagonist. Fenoldopam also inhibited insulin receptor mRNA and protein expression, which was time dependent and concentration dependent. A PKC or MAP kinase inhibitor blocked the inhibitory effect of fenoldopam on insulin receptor expression, indicating that PKC and MAP kinase were involved in the signaling pathway. CONCLUSION The inhibitory effect of D1-like receptors on insulin-mediated VSMC proliferation may play an important role in the regulation of blood pressure.
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40
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IGF-I/IGFBP-3 ratio: a mechanistic insight into the metabolic syndrome. Clin Sci (Lond) 2009; 116:507-12. [PMID: 18816247 DOI: 10.1042/cs20080382] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Recent reports suggest that IGF (insulin-like growth factor)-I and IGFBP-3 (IGF-binding protein-3) have independent and opposing mechanistic effects on insulin. The aim of the present study was to assess the relationship between the IGF-I/IGFBP-3 ratio and the metabolic syndrome. We examined 3281 subjects (1463 men and 1818 women, aged 20-49 years), otherwise healthy adults, who participated in NHANES III (Third National Health and Nutrition Examination Survey), which has released measurements of IGF-I and IGFBP-3. Insulin resistance was estimated using the computer HOMA2 (homoeostatic model assessment 2) model. The updated ATP-III (Adult Treatment Panel III) definition of the metabolic syndrome was used. We applied adjusted logistic and linear regression models. After adjusting for age and race, men and women in the lowest quartile of the IGF-I/IGFBP-3 ratio were 3-fold more likely to meet the ATP-III definition of the metabolic syndrome and twice as likely to be insulin-resistant. Mean values of the IGF-I/IGFBP-3 ratio decreased significantly as the number of metabolic syndrome components increased (P<0.0001, as determined by ANOVA). The area under the ROC (receiver operating characteristic) curve for detecting insulin resistance using the IGF-I/IGFBP-3 ratio was 0.760, significantly improving upon either protein alone (P=0.01). In conclusion, the IGF-I/IGFBP-3 ratio is significantly associated with the metabolic syndrome. Calculating the ratio of these two proteins may provide insight into the metabolic syndrome clustering phenomenon.
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Engberding N, San Martín A, Martin-Garrido A, Koga M, Pounkova L, Lyons E, Lassègue B, Griendling KK. Insulin-like growth factor-1 receptor expression masks the antiinflammatory and glucose uptake capacity of insulin in vascular smooth muscle cells. Arterioscler Thromb Vasc Biol 2009; 29:408-15. [PMID: 19122171 DOI: 10.1161/atvbaha.108.181727] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Insulin resistance of vascular smooth muscle cells (VSMCs) has been linked to accelerated atherosclerosis in diabetes; however, the effects of insulin on VSMCs remain controversial. Most VSMC insulin receptors are sequestered into insulin-insensitive hybrids with insulin-like growth factor-1 receptors (IGF1Rs). Thus we hypothesized that regulation of IGF1R expression may impact cellular insulin sensitivity. METHODS AND RESULTS IGF1R expression was increased in aortas from diabetic mice. IGF1R overexpression in VSMCs impaired insulin-induced Akt phosphorylation. Conversely, IGF1R downregulation by siRNA allowed assembly of insulin holoreceptors, enhanced insulin-induced phosphorylation of its receptor, Akt, Erk1/2, and further augmented insulin-induced glucose uptake. IGF1R downregulation uncovered an insulin-induced reduction in activation of NF-kappaB and inhibition of MCP-1 upregulation in response to TNF-alpha. CONCLUSIONS Downregulation of IGF1R increases the fraction of insulin receptors organized in holoreceptors, which leads to enhanced insulin signaling and unmasks potential antiinflammatory properties of insulin in VSMCs. Therefore, IGF1R, which is susceptible to feedback regulation by its own ligand, may represent a novel target for interventions designed to treat insulin resistance in the vasculature.
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Affiliation(s)
- Niels Engberding
- Department of Medicine, Division of Cardiology, Emory University, Atlanta, GA 30322, USA
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42
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Johansson GS, Chisalita SI, Arnqvist HJ. Human microvascular endothelial cells are sensitive to IGF-I but resistant to insulin at the receptor level. Mol Cell Endocrinol 2008; 296:58-63. [PMID: 18708119 DOI: 10.1016/j.mce.2008.07.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2008] [Revised: 07/15/2008] [Accepted: 07/16/2008] [Indexed: 11/18/2022]
Abstract
Human microvascular endothelial cells (HMVEC) are sensitive to IGF-I but insulin resistant and express several times more IGF-I receptors (IGF-IR) than insulin receptors (IR). Our aim was to investigate the mechanism of this insulin resistance in cultured HMVEC by studying receptor activation and signal propagation downstream. The IGF-IR beta-subunit and the IR beta-subunit were detected and found to co-precipitate. IRA was the major IR isoform expressed in HMVEC. IGF-I 10(-9) to 10(-8)M phosphorylated its cognate receptor beta-subunit. IGF-I also phosphorylated the IR beta-subunit at 10(-9)M. Phosphorylation of insulin receptor substrate 1 was obtained by IGF-I 10(-9) to 10(-8)M. Akt was phosphorylated by IGF-I at 10(-8) to 10(-7)M and by insulin 10(-7)M. IGF-I at 10(-8) to 10(-6)M significantly increased DNA-synthesis. We conclude that microvascular endothelial cells are sensitive to IGF-I but resistant to insulin due to a preponderance of IGF-I receptors and sequestration of insulin receptors into insulin/IGF-I hybrid receptors.
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Affiliation(s)
- G S Johansson
- Linköping University, Faculty of Health Sciences, Department of Clinical and Experimental Medicine, Division of Cell Biology, Linköping, Sweden.
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43
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Abbas A, Grant PJ, Kearney MT. Role of IGF-1 in glucose regulation and cardiovascular disease. Expert Rev Cardiovasc Ther 2008; 6:1135-49. [PMID: 18793116 DOI: 10.1586/14779072.6.8.1135] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
IGF-1 is a peptide hormone that is expressed in most tissues. It shares significant structural and functional similarities with insulin, and is implicated in the pathogenesis of insulin resistance and cardiovascular disease. Recombinant human IGF-1 has been used in Type 2 diabetes to improve insulin sensitivity and aid glycemic control. There is evidence supporting IGF-1 as a vascular protective factor and it may also be beneficial in the treatment of chronic heart failure. Further understanding of the effects of IGF-1 signaling in health and disease may lead to novel approaches to the prevention and treatment of diabetes and cardiovascular disease.
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Affiliation(s)
- Afroze Abbas
- BHF Clinical Research Fellow, Division of Cardiovascular and Diabetes Research, Leeds Institute of Genetics, Health and Therapeutics, University of Leeds, Leeds, UK.
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44
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Rowzee AM, Lazzarino DA, Rota L, Sun Z, Wood TL. IGF ligand and receptor regulation of mammary development. J Mammary Gland Biol Neoplasia 2008; 13:361-70. [PMID: 19020961 PMCID: PMC2665296 DOI: 10.1007/s10911-008-9102-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Accepted: 11/03/2008] [Indexed: 10/21/2022] Open
Abstract
The insulin-like growth factors, IGF-I and IGF-II, have endocrine as well as autocrine-paracrine actions on tissue growth. Both IGF ligands are expressed within developing mammary tissue throughout postnatal stages with specific sites of expression in the epithelial and stromal compartments. The elucidation of circulating versus local actions and of epithelial versus stromal actions of IGFs in stimulating mammary epithelial development has been the focus of several laboratories. The recent studies addressing IGF ligand function provide support for the hypotheses that (1) the diverse sites of IGF expression may mediate different cellular outcomes, and (2) IGF-I and IGF-II are distinctly regulated and have diverse functions in mammary development. The mechanisms for IGF function likely are mediated, in part, through diverse IGF signaling receptors. The local actions of the IGF ligands and receptors as revealed through recent publications are the focus of this review.
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Affiliation(s)
- Anne M Rowzee
- Department of Neurology & Neuroscience, University Hospital Cancer Center, New Jersey Medical School, UMDNJ, Newark, NJ, USA
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45
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Li M, Chiu JF, Gagne J, Fukagawa NK. Age-related differences in insulin-like growth factor-1 receptor signaling regulates Akt/FOXO3a and ERK/Fos pathways in vascular smooth muscle cells. J Cell Physiol 2008; 217:377-87. [PMID: 18615585 DOI: 10.1002/jcp.21507] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Advanced age is a major risk factor for atherosclerosis, but how aging per se influences pathogenesis is not clear. Insulin-like growth factor-1 receptor (IGF-1R) promotes aortic vascular smooth muscle cell (VSMC) growth, migration, and extracellular matrix formation, but how IGF-1R signaling changes with age in VSMC is not known. We previously found age-related differences in the activation of Akt/FOXO3a and ERK1/2 pathways in VSMC, but the upstream signaling remains unclear. Using explanted VSMC from Fischer 344/Brown Norway F1 hybrid rats shown to display age-related vascular pathology similar to humans, we compared IGF-1R expression in early passages of VSMC and found a constitutive activation of IGF-1R in VSMC from old compared to young rats, including IGF-1R expression and its tyrosine kinase activity. The link between IGF-1R activation and the Akt/FOXO3a and ERK pathways was confirmed through the induction of IGF-1R with IGF-1 in young cells and attenuation of IGF-1R with an inhibitor in old cells. The effects of three kinase inhibitors: AG1024, LY294002, and TCN, were compared in VSMC from old rats to differentiate IGF-1R from other upstream signaling that could also regulate the Akt/FOXO and ERK pathways. Genes for p27kip-1, catalase and MnSOD, which play important roles in the control of cell cycle arrest and stress resistance, were found to be FOXO3a-targets based on FOXO3a-siRNA treatment. Furthermore, IGF-1R signaling modulated these genes through activation of the Akt/FOXO3a pathway. Therefore, activation of IGF-1R signaling influences VSMC function in old rats and may contribute to the increased risk for atherosclerosis.
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Affiliation(s)
- Muyao Li
- Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont
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Le Roith D. Insulin glargine and receptor-mediated signalling: clinical implications in treating type 2 diabetes. Diabetes Metab Res Rev 2007; 23:593-9. [PMID: 17922476 DOI: 10.1002/dmrr.776] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Most patients with type 2 diabetes mellitus will eventually require insulin therapy to achieve or maintain adequate glycaemic control. The introduction of insulin analogues, with pharmacokinetics that more closely mimic endogenous insulin secretion, has made physiologic insulin replacement easier to achieve for many patients. However, there are also concerns regarding alteration of binding affinities for the insulin receptor (IR) or insulin-like growth factor-1 receptor (IGF-1R) may increase the mitogenic potential of some analogues. Therefore, this article will review the relevant preclinical and clinical data to assess the mitogenic potential of insulin glargine, a basal insulin analogue, compared with regular human insulin (RHI). Searches of the PubMed database were performed using terms that included 'IR,' 'insulin-like growth factor-1,' 'IGF-1R,' 'type 2 diabetes mellitus,' and 'insulin glargine.' Original articles and reviews of published literature were retrieved and reviewed. Although one study reported increased binding affinity of insulin glargine for the IGF-1R and increased mitogenic potential in cells with excess IGF-1Rs (Saos/B10 osteosarcoma cells), most in vitro binding-affinity and cell-culture studies have demonstrated behaviour of insulin glargine comparable to that of RHI for both IR and IGF-1R binding, insulin signalling, and metabolic and mitogenic potential.Currently published in vivo carcinogenic studies and human clinical trial data have shown that insulin glargine is not associated with increased risk for either cancer or the development or progression of diabetic retinopathy.
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Affiliation(s)
- Derek Le Roith
- Department of Medicine, The Mount Sinai School of Medicine, New York, NY 10029-6574, USA.
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Nichols TC, Busby WH, Merricks E, Sipos J, Rowland M, Sitko K, Clemmons DR. Protease-resistant insulin-like growth factor (IGF)-binding protein-4 inhibits IGF-I actions and neointimal expansion in a porcine model of neointimal hyperplasia. Endocrinology 2007; 148:5002-10. [PMID: 17640990 DOI: 10.1210/en.2007-0571] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
IGF-I has been shown to play a role in the progression of atherosclerosis in experimental animal models. IGF-binding protein-4 (IGFBP-4) binds to IGF-I and prevents its association with receptors. Overexpression of a protease-resistant form of IGFBP-4 has been shown to inhibit the ability of IGF-I to stimulate normal smooth muscle cell growth in mice. Based on these observations, we prepared a protease-resistant form of IGFBP-4 and infused it into hypercholesterolemic pigs. Infusion of the protease-resistant mutant inhibited lesion development by 53.3 +/- 6.1% (n = 6; P < 0.01). Control vessels that received an equimolar concentration of IGF-I and the protease-resistant IGFBP-4 showed no reduction in lesion size compared with control lesions that were infused with vehicle. Infusion of a nonmutated form of IGFBP-4 did not significantly inhibit lesion development. Proliferating cell nuclear antigen analysis showed that the mutant IGFBP-4 appeared to inhibit cell proliferation. The area occupied by extracellular matrix was also reduced proportionally compared with total lesion area. Immunoblotting revealed that the mutant IGFBP-4 remained intact, whereas the wild-type IGFBP-4 that was infused was proteolytically cleaved. Further analysis of the lesions revealed that a marker protein, IGFBP-5, whose synthesis is stimulated by IGF-I, was decreased in the lesions that received the protease-resistant, IGFBP-4 mutant, whereas there was no change in lesions that received wild-type IGFBP-4 or the mutant protein plus IGF-I. These findings clearly illustrate that infusion of protease-resistant IGFBP-4 into the perilesion environment results in inhibition of cell proliferation and attenuation of the development of neointima. The findings support the hypothesis that inhibiting IGFBP-4 proteolysis in the lesion microenvironment could be an effective means for regulating neointimal expansion.
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Affiliation(s)
- T C Nichols
- Division of Endocrinology, University of North Carolina at Chapel Hill, 8024 Burnett-Womack, Chapel Hill, NC 27599-7170, USA
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Xue F, Michels KB. Diabetes, metabolic syndrome, and breast cancer: a review of the current evidence. Am J Clin Nutr 2007; 86:s823-35. [PMID: 18265476 DOI: 10.1093/ajcn/86.3.823s] [Citation(s) in RCA: 250] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Incidences of breast cancer, type 2 diabetes, and metabolic syndrome have increased over the past decades with the obesity epidemic, especially in industrialized countries. Insulin resistance, hyperinsulinemia, and changes in the signaling of growth hormones and steroid hormones associated with diabetes may affect the risk of breast cancer. We reviewed epidemiologic studies of the association between type 2 diabetes and risk of breast cancer and the available evidence on the role of hormonal mediators of an association between diabetes and breast cancer. The combined evidence supports a modest association between type 2 diabetes and the risk of breast cancer, which appears to be more consistent among postmenopausal than among premenopausal women. Despite many proposed potential pathways, the mechanisms underlying an association between diabetes and breast cancer risk remain unclear, particularly because the 2 diseases share several risk factors, including obesity, a sedentary lifestyle, and possibly intake of saturated fat and refined carbohydrates, that may confound this association. Although the metabolic syndrome is closely related to diabetes and embraces additional components that might influence breast cancer risk, the role of the metabolic syndrome in breast carcinogenesis has not been studied and thus remains unknown.
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Affiliation(s)
- Fei Xue
- Obstetrics and Gynecology Epidemiology Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
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Abstract
Insulin has important vascular actions to stimulate production of nitric oxide from endothelium. This leads to capillary recruitment, vasodilation, increased blood flow, and subsequent augmentation of glucose disposal in classical insulin target tissues (e.g., skeletal muscle). Phosphatidylinositol 3-kinase-dependent insulin-signaling pathways regulating endothelial production of nitric oxide share striking parallels with metabolic insulin-signaling pathways. Distinct MAPK-dependent insulin-signaling pathways (largely unrelated to metabolic actions of insulin) regulate secretion of the vasoconstrictor endothelin-1 from endothelium. These and other cardiovascular actions of insulin contribute to coupling metabolic and hemodynamic homeostasis under healthy conditions. Cardiovascular diseases are the leading cause of morbidity and mortality in insulin-resistant individuals. Insulin resistance is typically defined as decreased sensitivity and/or responsiveness to metabolic actions of insulin. This cardinal feature of diabetes, obesity, and dyslipidemia is also a prominent component of hypertension, coronary heart disease, and atherosclerosis that are all characterized by endothelial dysfunction. Conversely, endothelial dysfunction is often present in metabolic diseases. Insulin resistance is characterized by pathway-specific impairment in phosphatidylinositol 3-kinase-dependent signaling that in vascular endothelium contributes to a reciprocal relationship between insulin resistance and endothelial dysfunction. The clinical relevance of this coupling is highlighted by the findings that specific therapeutic interventions targeting insulin resistance often also ameliorate endothelial dysfunction (and vice versa). In this review, we discuss molecular mechanisms underlying cardiovascular actions of insulin, the reciprocal relationships between insulin resistance and endothelial dysfunction, and implications for developing beneficial therapeutic strategies that simultaneously target metabolic and cardiovascular diseases.
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Affiliation(s)
- Ranganath Muniyappa
- Diabetes Unit, National Center for Complementary and Alternative Medicine, National Institutes of Health, Bethesda, Maryland 20892-1632, USA
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50
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Schaafsma D, McNeill KD, Stelmack GL, Gosens R, Baarsma HA, Dekkers BGJ, Frohwerk E, Penninks JM, Sharma P, Ens KM, Nelemans SA, Zaagsma J, Halayko AJ, Meurs H. Insulin increases the expression of contractile phenotypic markers in airway smooth muscle. Am J Physiol Cell Physiol 2007; 293:C429-39. [PMID: 17459944 DOI: 10.1152/ajpcell.00502.2006] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
We have previously demonstrated that long-term exposure of bovine tracheal smooth muscle (BTSM) strips to insulin induces a functional hypercontractile phenotype. To elucidate molecular mechanisms by which insulin might induce maturation of contractile phenotype airway smooth muscle (ASM) cells, we investigated effects of insulin stimulation in serum-free primary BTSM cell cultures on protein accumulation of specific contractile phenotypic markers and on the abundance and stability of mRNA encoding these markers. In addition, we used microscopy to assess insulin effects on ASM cell morphology, phenotype, and induction of phosphatidylinositol (PI) 3-kinase signaling. It was demonstrated that protein and mRNA levels of smooth muscle-specific contractile phenotypic markers, including sm-myosin, are significantly increased after stimulation of cultured BTSM cells with insulin (1 microM) for 8 days compared with cells treated with serum-free media, whereas mRNA stability was unaffected. In addition, insulin treatment promoted the formation of large, elongate ASM cells, characterized by dramatic accumulation of contractile phenotype marker proteins and phosphorylated p70(S6K) (downstream target of PI 3-kinase associated with ASM maturation). Insulin effects on protein accumulation and cell morphology were abrogated by combined pretreatment with the Rho kinase inhibitor Y-27632 (1 microM) or the PI 3-kinase inhibitor LY-294002 (10 microM), indicating that insulin increases the expression of contractile phenotypic markers in BTSM in a Rho kinase- and PI 3-kinase-dependent fashion. In conclusion, insulin increases transcription and protein expression of contractile phenotypic markers in ASM. This could have important implications for the use of recently approved aerosolized insulin formulations in diabetes mellitus.
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MESH Headings
- Amides/pharmacology
- Animals
- Calcium-Binding Proteins/metabolism
- Cattle
- Cell Shape/drug effects
- Cells, Cultured
- Chromones/pharmacology
- Contractile Proteins/genetics
- Contractile Proteins/metabolism
- Hypoglycemic Agents/metabolism
- Hypoglycemic Agents/pharmacology
- Insulin/metabolism
- Insulin/pharmacology
- Intracellular Signaling Peptides and Proteins/antagonists & inhibitors
- Intracellular Signaling Peptides and Proteins/metabolism
- Microfilament Proteins/metabolism
- Morpholines/pharmacology
- Muscle Contraction/drug effects
- Muscle Contraction/genetics
- Muscle, Smooth/cytology
- Muscle, Smooth/drug effects
- Muscle, Smooth/metabolism
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Organ Culture Techniques
- Phenotype
- Phosphatidylinositol 3-Kinases/metabolism
- Phosphoinositide-3 Kinase Inhibitors
- Phosphorylation
- Protein Biosynthesis/drug effects
- Protein Kinase Inhibitors/pharmacology
- Protein Serine-Threonine Kinases/antagonists & inhibitors
- Protein Serine-Threonine Kinases/metabolism
- Pyridines/pharmacology
- RNA, Messenger/metabolism
- Receptor, IGF Type 1/metabolism
- Receptor, IGF Type 2/metabolism
- Receptor, Insulin/metabolism
- Ribosomal Protein S6 Kinases, 70-kDa/metabolism
- Signal Transduction/drug effects
- Smooth Muscle Myosins/metabolism
- Time Factors
- Trachea/cytology
- Trachea/drug effects
- Trachea/metabolism
- Transcription, Genetic/drug effects
- rho-Associated Kinases
- Calponins
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Affiliation(s)
- Dedmer Schaafsma
- Dept. of Molecular Pharmacology, University of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands.
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