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Li K, Bartlett JA, Wohlford-Lenane CL, Xue B, Thurman AL, Gallagher TM, Pezzulo AA, McCray PB. Interleukin 13-Induced Inflammation Increases DPP4 Abundance but Does Not Enhance Middle East Respiratory Syndrome Coronavirus Replication in Airway Epithelia. J Infect Dis 2024; 229:1419-1429. [PMID: 37698016 PMCID: PMC11095549 DOI: 10.1093/infdis/jiad383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 08/18/2023] [Accepted: 09/08/2023] [Indexed: 09/13/2023] Open
Abstract
BACKGROUND Chronic pulmonary conditions such as asthma and chronic obstructive pulmonary disease increase the risk of morbidity and mortality during infection with the Middle East respiratory syndrome coronavirus (MERS-CoV). We hypothesized that individuals with such comorbidities are more susceptible to MERS-CoV infection due to increased expression of its receptor, dipeptidyl peptidase 4 (DPP4). METHODS We modeled chronic airway disease by treating primary human airway epithelia with the Th2 cytokine interleukin 13 (IL-13), examining how this affected DPP4 protein levels with MERS-CoV entry and replication. RESULTS IL-13 exposure for 3 days led to greater DPP4 protein abundance, while a 21-day treatment raised DPP4 levels and caused goblet cell metaplasia. Surprisingly, despite this increase in receptor availability, MERS-CoV entry and replication were not significantly affected by IL-13 treatment. CONCLUSIONS Our results suggest that greater DPP4 abundance is likely not the primary mechanism leading to increased MERS severity in the setting of Th2 inflammation. Transcriptional profiling analysis highlighted the complexity of IL-13-induced changes in airway epithelia, including altered expression of genes involved in innate immunity, antiviral responses, and maintenance of the extracellular mucus barrier. These data suggest that additional factors likely interact with DPP4 abundance to determine MERS-CoV infection outcomes.
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Affiliation(s)
- Kun Li
- Department of Pediatrics, Pappajohn Biomedical Institute, Carver College of Medicine, University of Iowa, Iowa City, IA
| | - Jennifer A Bartlett
- Department of Pediatrics, Pappajohn Biomedical Institute, Carver College of Medicine, University of Iowa, Iowa City, IA
| | - Christine L Wohlford-Lenane
- Department of Pediatrics, Pappajohn Biomedical Institute, Carver College of Medicine, University of Iowa, Iowa City, IA
| | - Biyun Xue
- Department of Internal Medicine, Pappajohn Biomedical Institute, Carver College of Medicine, University of Iowa, Iowa City, IA
| | - Andrew L Thurman
- Department of Internal Medicine, Pappajohn Biomedical Institute, Carver College of Medicine, University of Iowa, Iowa City, IA
| | - Thomas M Gallagher
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, IL
| | - Alejandro A Pezzulo
- Department of Internal Medicine, Pappajohn Biomedical Institute, Carver College of Medicine, University of Iowa, Iowa City, IA
| | - Paul B McCray
- Department of Pediatrics, Pappajohn Biomedical Institute, Carver College of Medicine, University of Iowa, Iowa City, IA
- Department of Microbiology, Pappajohn Biomedical Institute, Carver College of Medicine, University of Iowa, Iowa City, IA
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Niebrzydowska-Tatus M, Pełech A, Bień K, Mekler J, Santiago M, Kimber-Trojnar Ż, Trojnar M. Association of DPP-4 Concentrations with the Occurrence of Gestational Diabetes Mellitus and Excessive Gestational Weight Gain. Int J Mol Sci 2024; 25:1829. [PMID: 38339106 PMCID: PMC10855185 DOI: 10.3390/ijms25031829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/24/2024] [Accepted: 01/31/2024] [Indexed: 02/12/2024] Open
Abstract
Gestational diabetes mellitus (GDM) is considered one of the most common diseases that occur during pregnancy. In addition to increasing the risk of numerous complications throughout gestation, it is also believed to have a long-term potential to impact the risk of developing type 2 diabetes mellitus (T2DM) and cardiovascular disease for the mother and her offspring. While there are clear guidelines for healthy weight gain in pregnancy depending on pre-pregnancy BMI, as well as dietary and training recommendations to achieve this, an increasing number of women are experiencing excessive gestational weight gain (EGWG). Such patients have a higher risk of developing GDM and gestational hypertension, as well as requiring caesarian delivery. Dipeptidyl peptidase-4 (DPP-4) is a glycoprotein that seems to play an important role in glucose metabolism, and inhibition of its activity positively affects glucose regulation. The aim of our study was to compare DPP-4 concentrations in patients with GDM and EGWG with healthy women. DPP-4 levels were assessed in serum and urine samples collected on the day of delivery. The bioelectrical impedance analysis (BIA) method was also used to analyze the body composition of patients on the second day of the postpartum period. DPP-4 serum concentrations were significantly higher in patients in the GDM and EGWG groups compared to healthy women. Urinary DPP-4 concentrations were significantly higher in the control and GDM groups than in the EGWG group. Serum DPP-4 levels were positively correlated with BMI measured before pregnancy, on the delivery day, and in the early postpartum period, among other factors. According to our knowledge, this is the first study to determine DPP-4 levels in EGWG patients. DPP-4 may be related to the occurrence of GDM and EGWG; however, this requires further research.
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Affiliation(s)
- Magdalena Niebrzydowska-Tatus
- Chair and Department of Obstetrics and Perinatology, Medical University of Lublin, 20-090 Lublin, Poland; (M.N.-T.); (A.P.)
| | - Aleksandra Pełech
- Chair and Department of Obstetrics and Perinatology, Medical University of Lublin, 20-090 Lublin, Poland; (M.N.-T.); (A.P.)
| | - Katarzyna Bień
- Student’s Scientific Association at the Chair and Department of Obstetrics and Perinatology, Medical University of Lublin, 20-090 Lublin, Poland; (K.B.); (J.M.); (M.S.)
| | - Julia Mekler
- Student’s Scientific Association at the Chair and Department of Obstetrics and Perinatology, Medical University of Lublin, 20-090 Lublin, Poland; (K.B.); (J.M.); (M.S.)
| | - Miracle Santiago
- Student’s Scientific Association at the Chair and Department of Obstetrics and Perinatology, Medical University of Lublin, 20-090 Lublin, Poland; (K.B.); (J.M.); (M.S.)
| | - Żaneta Kimber-Trojnar
- Chair and Department of Obstetrics and Perinatology, Medical University of Lublin, 20-090 Lublin, Poland; (M.N.-T.); (A.P.)
| | - Marcin Trojnar
- Chair and Department of Internal Diseases, Medical University of Lublin, 20-059 Lublin, Poland;
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Stentz R, Jones E, Juodeikis R, Wegmann U, Guirro M, Goldson AJ, Brion A, Booth C, Sudhakar P, Brown IR, Korcsmáros T, Carding SR. The Proteome of Extracellular Vesicles Produced by the Human Gut Bacteria Bacteroides thetaiotaomicron In Vivo Is Influenced by Environmental and Host-Derived Factors. Appl Environ Microbiol 2022; 88:e0053322. [PMID: 35916501 PMCID: PMC9397113 DOI: 10.1128/aem.00533-22] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 07/11/2022] [Indexed: 11/20/2022] Open
Abstract
Bacterial extracellular vesicles (BEVs) released from both Gram-negative and Gram-positive bacteria provide an effective means of communication and trafficking of cell signaling molecules. In the gastrointestinal tract (GIT) BEVs produced by members of the intestinal microbiota can impact host health by mediating microbe-host cell interactions. A major unresolved question, however, is what factors influence the composition of BEV proteins and whether the host influences protein packaging into BEVs and secretion into the GIT. To address this, we have analyzed the proteome of BEVs produced by the major human gut symbiont Bacteroides thetaiotaomicron both in vitro and in vivo in the murine GIT in order to identify proteins specifically enriched in BEVs produced in vivo. We identified 113 proteins enriched in BEVs produced in vivo, the majority (62/113) of which accumulated in BEVs in the absence of any changes in their expression by the parental cells. Among these selectively enriched proteins, we identified dipeptidyl peptidases and an asparaginase and confirmed their increased activity in BEVs produced in vivo. We also showed that intact BEVs are capable of degrading bile acids via a bile salt hydrolase. Collectively these findings provide additional evidence for the dynamic interplay of host-microbe interactions in the GIT and the existence of an active mechanism to drive and enrich a selected group of proteins for secretion into BEVs in the GIT. IMPORTANCE The gastrointestinal tract (GIT) harbors a complex community of microbes termed the microbiota that plays a role in maintaining the host's health and wellbeing. How this comes about and the nature of microbe-host cell interactions in the GIT is still unclear. Recently, nanosized vesicles naturally produced by bacterial constituents of the microbiota have been shown to influence responses of different host cells although the molecular basis and identity of vesicle-born bacterial proteins that mediate these interactions is unclear. We show here that bacterial extracellular vesicles (BEVs) produced by the human symbiont Bacteroides thetaiotaomicron in the GIT are enriched in a set of proteins and enzymes, including dipeptidyl peptidases, an asparaginase and a bile salt hydrolase that can influence host cell biosynthetic pathways. Our results provide new insights into the molecular basis of microbiota-host interactions that are central to maintaining GIT homeostasis and health.
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Affiliation(s)
- Régis Stentz
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, United Kingdom
| | - Emily Jones
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, United Kingdom
| | - Rokas Juodeikis
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, United Kingdom
| | - Udo Wegmann
- School of Chemistry, University East Anglia, Norwich, United Kingdom
| | - Maria Guirro
- Biochemistry and Biotechnology Department, Nutrigenomics Research Group, Universitat Rovira i Virgili, Tarragona, Spain
- Eurecat, Centre Tecnològic de Catalunya, Centre for Omic Sciences (COS), Joint Unit Universitat Rovira i Virgili-EURECAT, Unique Scientific and Technical Infrastructures (ICTS), Reus, Spain
| | - Andrew J. Goldson
- Core Science Resources Quadram Institute Bioscience, Norwich, United Kingdom
| | - Arlaine Brion
- Core Science Resources Quadram Institute Bioscience, Norwich, United Kingdom
| | - Catherine Booth
- Core Science Resources Quadram Institute Bioscience, Norwich, United Kingdom
| | - Padhmanand Sudhakar
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, United Kingdom
- Earlham Institute, Norwich, United Kingdom
- Department of Chronic Diseases, Metabolism and Ageing, TARGID, KU Leuven, Leuven, Belgium
| | - Ian R. Brown
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Tamás Korcsmáros
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, United Kingdom
- Earlham Institute, Norwich, United Kingdom
| | - Simon R. Carding
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, United Kingdom
- Norwich Medical School, University East Anglia, Norwich, United Kingdom
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Jonik S, Marchel M, Grabowski M, Opolski G, Mazurek T. Gastrointestinal Incretins-Glucose-Dependent Insulinotropic Polypeptide (GIP) and Glucagon-like Peptide-1 (GLP-1) beyond Pleiotropic Physiological Effects Are Involved in Pathophysiology of Atherosclerosis and Coronary Artery Disease-State of the Art. BIOLOGY 2022; 11:biology11020288. [PMID: 35205155 PMCID: PMC8869592 DOI: 10.3390/biology11020288] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/03/2022] [Accepted: 02/07/2022] [Indexed: 02/06/2023]
Abstract
Simple Summary The presented manuscript contains the most current and extensive summary of the role of the most predominant gastrointestinal hormones—GIP and GLP-1 in the pathophysiology of atherosclerosis and coronary artery disease both in animals and humans. We have described GIP and GLP-1 as (1) expressed in many human tissues, (2) emphasized relationship between GIP and GLP-1 and inflammation, (3) highlighted importance of GIP and GLP-1-dependent pathways in atherosclerosis and coronary artery disease and (4) proved that GIP and GLP-1 could be used as markers of incidence, clinical course and recurrence of coronary artery disease, and related to extent and severity of atherosclerosis and myocardial ischemia. Our initial review may state a cornerstone for the future, however, there are still many unknowns and understatements on this topic. Due to the widespread growing interest for the potential use of incretins in cardiovascular diseases, we think that further research in this direction is desirable. For the future, we would like to recognize GIP and GLP-1 as widely implemented into clinical practice as new biomarkers of atherosclerosis and coronary artery disease. Abstract Coronary artery disease (CAD), which is the manifestation of atherosclerosis in coronary arteries, is the most common single cause of death and is responsible for disabilities of millions of people worldwide. Despite numerous dedicated clinical studies and an enormous effort to develop diagnostic and therapeutic methods, coronary atherosclerosis remains one of the most serious medical problems of the modern world. Hence, new markers are still being sought to identify and manage CAD optimally. Trying to face this problem, we have raised the question of the most predominant gastrointestinal hormones; glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), mainly involved in carbohydrates disorders, could be also used as new markers of incidence, clinical course, and recurrence of CAD and are related to extent and severity of atherosclerosis and myocardial ischemia. We describe GIP and GLP-1 as expressed in many animal and human tissues, known to be connected to inflammation and related to enormous noncardiac and cardiovascular (CV) diseases. In animals, GIP and GLP-1 improve endothelial function and lead to reduced atherosclerotic plaque macrophage infiltration and stabilize atherosclerotic lesions by directly blocking monocyte migration. Moreover, in humans, GIPR activation induces the pro-atherosclerotic factors ET-1 (endothelin-1) and OPN (osteopontin) but also has anti-atherosclerotic effects through secretion of NO (nitric oxide). Furthermore, four large clinical trials showed a significant reduction in composite of CV death, MI, and stroke in long-term follow-up using GLP-1 analogs for DM 2 patients: liraglutide in LEADER, semaglutide in SUSTAIN-6, dulaglutide in REWIND and albiglutide in HARMONY. However, very little is known about GIP metabolism in the acute phase of myocardial ischemia or for stable patients with CAD, which constitutes a direction for future research. This review aims to comprehensively discuss the impact of GIP and GLP-1 on atherosclerosis and CAD and its potential therapeutic implications.
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Suresh PS, Singh PP, Padwad YS, Sharma U. Steroidal saponins from Trillium govanianum as α-amylase, α-glucosidase, and dipeptidyl peptidase IV inhibitory agents. J Pharm Pharmacol 2021; 73:487-495. [PMID: 33793831 DOI: 10.1093/jpp/rgaa038] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 10/27/2020] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To provide the scientific basis for the utility of rhizome of Trillium govanianum as nutraceutical supplements in managing physiological glycemic levels. METHODS The in vitro enzyme inhibitory activity of the extract, fractions, and the isolated steroidal saponins from the rhizome part of T. govanianum was carried out against α-amylase, α-glucosidase, and dipeptidyl peptidase IV. The molecular interactions, binding score, and pharmacokinetic parameters (absorption, distribution metabolism, and excretion) of steroidal saponins were analyzed by the Schrodinger molecular docking software. KEY FINDINGS Current study explained that the extract, fractions, and isolated steroidal saponins from T. govanianum possess good α-amylase and α-glucosidase inhibitory activity while moderate dipeptidyl peptidase IV inhibitory activity. Moreover, in vitro results revealed that borassoside E (IC50 7.15 ± 1.78 μM), protodioscin (IC50 6.72 ± 0.04 μM), and diosgenin (IC50 12.75 ± 2.70 μM) are most effective in inhibiting the activity of α-amylase, α-glucosidase, and dipeptidyl peptidase IV, respectively. Current in silico and in vitro studies established an association between the steroidal saponins from T. govanianum and their molecular interactions with α-amylase, α-glucosidase, and dipeptidyl peptidase IV. CONCLUSION The results of this investigation suggest that fractions and steroidal saponins from T. govanianum exhibit good antidiabetic activity which could be used as nutraceutical supplements for the management of systemic glucose level.
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Affiliation(s)
- Patil Shivprasad Suresh
- Chemical Technology Division, CSIR-IHBT, Palampur, India.,Food and Nutraceuticals Division, CSIR-IHBT, Palampur, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, U.P., India
| | - Prithvi Pal Singh
- Chemical Technology Division, CSIR-IHBT, Palampur, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, U.P., India
| | - Yogendra S Padwad
- Food and Nutraceuticals Division, CSIR-IHBT, Palampur, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, U.P., India
| | - Upendra Sharma
- Chemical Technology Division, CSIR-IHBT, Palampur, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, U.P., India
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Chromatin and transcriptome changes in human myoblasts show spatio-temporal correlations and demonstrate DPP4 inhibition in differentiated myotubes. Sci Rep 2020; 10:14336. [PMID: 32868771 PMCID: PMC7459101 DOI: 10.1038/s41598-020-70756-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 03/03/2020] [Indexed: 12/03/2022] Open
Abstract
Although less attention was paid to understanding physical localization changes in cell nuclei recently, depicting chromatin interaction maps is a topic of high interest. Here, we focused on defining extensive physical changes in chromatin organization in the process of skeletal myoblast differentiation. Based on RNA profiling data and 3D imaging of myogenic (NCAM1, DES, MYOG, ACTN3, MYF5, MYF6, ACTN2, and MYH2) and other selected genes (HPRT1, CDH15, DPP4 and VCAM1), we observed correlations between the following: (1) expression change and localization, (2) a gene and its genomic neighbourhood expression and (3) intra-chromosome and microscopical locus-centromere distances. In particular, we demonstrated the negative regulation of DPP4 mRNA (p < 0.001) and protein (p < 0.05) in differentiated myotubes, which coincided with a localization change of the DPP4 locus towards the nuclear lamina (p < 0.001) and chromosome 2 centromere (p < 0.001). Furthermore, we discuss the possible role of DPP4 in myoblasts (supported by an inhibition assay). We also provide positive regulation examples (VCAM1 and MYH2). Overall, we describe for the first time existing mechanisms of spatial gene expression regulation in myoblasts that might explain the issue of heterogenic responses observed during muscle regenerative therapies.
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Park DS, Kim K, Jang M, Choi SC. Role of dipeptidyl peptidase-4 as a potentiator of activin/nodal signaling pathway. BMB Rep 2018. [PMID: 30463640 PMCID: PMC6330939 DOI: 10.5483/bmbrep.2018.51.12.210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
DPP4 (dipeptidyl peptidase-4), a highly conserved transmembrane glycoprotein with an exo-peptidase activity, has been shown to contribute to glucose metabolism, immune regulation, signal transduction, and cell differentiation. Here, we show that DPP4 is involved in control of activin/nodal signaling in Xenopus early development. In support of this, gain of function of DPP4 augmented Smad2 phosphorylation as well as expression of target genes induced by activin or nodal signal. In addition, Dpp4 and Xnr1 showed synergistic effect on induction of ectopic dorsal body axis, when co-injected at suboptimal doses in early embryos. Conversely, saxagliptin, a DPP4 inhibitor repressed activin induction of Smad2 phosphorylation. Notably, overexpression of Dpp4 disrupted specification of dorsal body axis of embryo, leading to malformed phenotypes such as spina bifida and a shortened and dorsally bent axis. Together, these results suggest that DPP4 functions as a potentiator of activin/nodal signaling pathway.
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Affiliation(s)
- Dong-Seok Park
- Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Kyuhee Kim
- Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Minjoo Jang
- Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Sun-Cheol Choi
- Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul 05505, Korea
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Abrahami D, Douros A, Yin H, Yu OHY, Renoux C, Bitton A, Azoulay L. Dipeptidyl peptidase-4 inhibitors and incidence of inflammatory bowel disease among patients with type 2 diabetes: population based cohort study. BMJ 2018; 360:k872. [PMID: 29563098 PMCID: PMC5861502 DOI: 10.1136/bmj.k872] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
OBJECTIVE To assess whether the use of dipeptidyl peptidase-4 inhibitors is associated with the incidence of inflammatory bowel disease in patients with type 2 diabetes. DESIGN Population based cohort study. SETTING More than 700 general practices contributing data to the United Kingdom Clinical Practice Research Datalink. PARTICIPANTS A cohort of 141 170 patients, at least 18 years of age, starting antidiabetic drugs between 1 January 2007 and 31 December 2016, with follow-up until 30 June 2017. MAIN OUTCOME MEASURES Adjusted hazard ratios for incident inflammatory bowel disease associated with use of dipeptidyl peptidase-4 inhibitors overall, by cumulative duration of use, and by time since initiation, estimated using time dependent Cox proportional hazards models. Use of dipeptidyl peptidase-4 inhibitors was modelled as a time varying variable and compared with use of other antidiabetic drugs, with exposures lagged by six months to account for latency and diagnostic delays. RESULTS During 552 413 person years of follow-up, 208 incident inflammatory bowel disease events occurred (crude incidence rate of 37.7 (95% confidence interval 32.7 to 43.1) per 100 000 person years). Overall, use of dipeptidyl peptidase-4 inhibitors was associated with an increased risk of inflammatory bowel disease (53.4 v 34.5 per 100 000 person years; hazard ratio 1.75, 95% confidence interval 1.22 to 2.49). Hazard ratios gradually increased with longer durations of use, reaching a peak after three to four years of use (hazard ratio 2.90, 1.31 to 6.41) and decreasing after more than four years of use (1.45, 0.44 to 4.76). A similar pattern was observed with time since starting dipeptidyl peptidase-4 inhibitors. These findings remained consistent in several sensitivity analyses. CONCLUSIONS In this first population based study, the use of dipeptidyl peptidase-4 inhibitors was associated with an increased risk of inflammatory bowel disease. Although these findings need to be replicated, physicians should be aware of this possible association.
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Affiliation(s)
- Devin Abrahami
- Centre for Clinical Epidemiology, Lady Davis Institute, Jewish General Hospital, Montreal, QC, Canada H3T 1E2
- Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, QC, Canada
| | - Antonios Douros
- Centre for Clinical Epidemiology, Lady Davis Institute, Jewish General Hospital, Montreal, QC, Canada H3T 1E2
- Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, QC, Canada
- Institute of Clinical Pharmacology and Toxicology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Hui Yin
- Centre for Clinical Epidemiology, Lady Davis Institute, Jewish General Hospital, Montreal, QC, Canada H3T 1E2
| | - Oriana Hoi Yun Yu
- Centre for Clinical Epidemiology, Lady Davis Institute, Jewish General Hospital, Montreal, QC, Canada H3T 1E2
- Division of Endocrinology, Jewish General Hospital, Montreal, QC, Canada
| | - Christel Renoux
- Centre for Clinical Epidemiology, Lady Davis Institute, Jewish General Hospital, Montreal, QC, Canada H3T 1E2
- Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, QC, Canada
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Alain Bitton
- Division of Gastroenterology, Department of Medicine, McGill University, Montreal, QC, Canada
- McGill University Health Centre, Montreal, QC, Canada
| | - Laurent Azoulay
- Centre for Clinical Epidemiology, Lady Davis Institute, Jewish General Hospital, Montreal, QC, Canada H3T 1E2
- Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, QC, Canada
- Gerald Bronfman Department of Oncology, McGill University, Montreal, QC, Canada
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Paternoster S, Falasca M. Dissecting the Physiology and Pathophysiology of Glucagon-Like Peptide-1. Front Endocrinol (Lausanne) 2018; 9:584. [PMID: 30364192 PMCID: PMC6193070 DOI: 10.3389/fendo.2018.00584] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 09/14/2018] [Indexed: 12/11/2022] Open
Abstract
An aging world population exposed to a sedentary life style is currently plagued by chronic metabolic diseases, such as type-2 diabetes, that are spreading worldwide at an unprecedented rate. One of the most promising pharmacological approaches for the management of type 2 diabetes takes advantage of the peptide hormone glucagon-like peptide-1 (GLP-1) under the form of protease resistant mimetics, and DPP-IV inhibitors. Despite the improved quality of life, long-term treatments with these new classes of drugs are riddled with serious and life-threatening side-effects, with no overall cure of the disease. New evidence is shedding more light over the complex physiology of GLP-1 in health and metabolic diseases. Herein, we discuss the most recent advancements in the biology of gut receptors known to induce the secretion of GLP-1, to bridge the multiple gaps into our understanding of its physiology and pathology.
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Sato H, Kubota N, Kubota T, Takamoto I, Iwayama K, Tokuyama K, Moroi M, Sugi K, Nakaya K, Goto M, Jomori T, Kadowaki T. Anagliptin increases insulin-induced skeletal muscle glucose uptake via an NO-dependent mechanism in mice. Diabetologia 2016; 59:2426-2434. [PMID: 27525648 DOI: 10.1007/s00125-016-4071-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Accepted: 07/04/2016] [Indexed: 10/21/2022]
Abstract
AIMS/HYPOTHESIS Recently, incretin-related agents have been reported to attenuate insulin resistance in animal models, although the underlying mechanisms remain unclear. In this study, we investigated whether anagliptin, the dipeptidyl peptidase 4 (DPP-4) inhibitor, attenuates skeletal muscle insulin resistance through endothelial nitric oxide synthase (eNOS) activation in the endothelial cells. We used endothelium-specific Irs2-knockout (ETIrs2KO) mice, which show skeletal muscle insulin resistance resulting from a reduction of insulin-induced skeletal muscle capillary recruitment as a consequence of impaired eNOS activation. METHODS In vivo, 8-week-old male ETIrs2KO mice were fed regular chow with or without 0.3% (wt/wt) DPP-4 inhibitor for 8 weeks to assess capillary recruitment and glucose uptake by the skeletal muscle. In vitro, human coronary arterial endothelial cells (HCAECs) were used to explore the effect of glucagon-like peptide 1 (GLP-1) on eNOS activity. RESULTS Treatment with anagliptin ameliorated the impaired insulin-induced increase in capillary blood volume, interstitial insulin concentration and skeletal muscle glucose uptake in ETIrs2KO mice. This improvement in insulin-induced glucose uptake was almost completely abrogated by the GLP-1 receptor (GLP-1R) antagonist exendin-(9-39). Moreover, the increase in capillary blood volume with anagliptin treatment was also completely inhibited by the NOS inhibitor. GLP-1 augmented eNOS phosphorylation in HCAECs, with the effect completely disappearing after exposure to the protein kinase A (PKA) inhibitor H89. These data suggest that anagliptin treatment enhances insulin-induced capillary recruitment and interstitial insulin concentrations, resulting in improved skeletal muscle glucose uptake by directly acting on the endothelial cells via NO- and GLP-1-dependent mechanisms in vivo. CONCLUSIONS/INTERPRETATION Anagliptin may be a promising agent to ameliorate skeletal muscle insulin resistance in obese patients with type 2 diabetes.
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Affiliation(s)
- Hiroyuki Sato
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Naoto Kubota
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
- Department of Clinical Nutrition Therapy, University of Tokyo, Tokyo, Japan.
- Clinical Nutrition Program, National Institute of Health and Nutrition, Tokyo, Japan.
- Laboratory for Metabolic Homeostasis, RIKEN Center for Integrative Medical Sciences, Kanagawa, Japan.
| | - Tetsuya Kubota
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
- Clinical Nutrition Program, National Institute of Health and Nutrition, Tokyo, Japan
- Laboratory for Metabolic Homeostasis, RIKEN Center for Integrative Medical Sciences, Kanagawa, Japan
- Division of Cardiovascular Medicine, Toho University Ohashi Medical Center, Tokyo, Japan
| | - Iseki Takamoto
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Kaito Iwayama
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan
| | - Kumpei Tokuyama
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan
| | - Masao Moroi
- Division of Cardiovascular Medicine, Toho University Ohashi Medical Center, Tokyo, Japan
| | - Kaoru Sugi
- Division of Cardiovascular Medicine, Toho University Ohashi Medical Center, Tokyo, Japan
| | - Keizo Nakaya
- Mie Research Laboratories, Sanwa Kagaku Kenkyusho Co. Ltd, Mie, Japan
| | - Moritaka Goto
- Mie Research Laboratories, Sanwa Kagaku Kenkyusho Co. Ltd, Mie, Japan
| | - Takahito Jomori
- Mie Research Laboratories, Sanwa Kagaku Kenkyusho Co. Ltd, Mie, Japan
| | - Takashi Kadowaki
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
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11
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Wilson CH, Zhang HE, Gorrell MD, Abbott CA. Dipeptidyl peptidase 9 substrates and their discovery: current progress and the application of mass spectrometry-based approaches. Biol Chem 2016; 397:837-56. [DOI: 10.1515/hsz-2016-0174] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 07/04/2016] [Indexed: 12/16/2022]
Abstract
Abstract
The enzyme members of the dipeptidyl peptidase 4 (DPP4) gene family have the very unusual capacity to cleave the post-proline bond to release dipeptides from the N-terminus of peptide/protein substrates. DPP4 and related enzymes are current and potential therapeutic targets in the treatment of type II diabetes, inflammatory conditions and cancer. Despite this, the precise biological function of individual dipeptidyl peptidases (DPPs), other than DPP4, and knowledge of their in vivo substrates remains largely unknown. For many years, identification of physiological DPP substrates has been difficult due to limitations in the available tools. Now, with advances in mass spectrometry based approaches, we can discover DPP substrates on a system wide-scale. Application of these approaches has helped reveal some of the in vivo natural substrates of DPP8 and DPP9 and their unique biological roles. In this review, we provide a general overview of some tools and approaches available for protease substrate discovery and their applicability to the DPPs with a specific focus on DPP9 substrates. This review provides comment upon potential approaches for future substrate elucidation.
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12
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Zhao BT, Le DD, Nguyen PH, Ali MY, Choi JS, Min BS, Shin HM, Rhee HI, Woo MH. PTP1B, α-glucosidase, and DPP-IV inhibitory effects for chromene derivatives from the leaves of Smilax china L. Chem Biol Interact 2016; 253:27-37. [PMID: 27060210 DOI: 10.1016/j.cbi.2016.04.012] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 03/16/2016] [Accepted: 04/05/2016] [Indexed: 12/29/2022]
Abstract
Two new flavonoids, bismilachinone (11) and smilachinin (14), were isolated from the leaves of Smilax china L. together with 14 known compounds. Their structures were elucidated using spectroscopic methods. The PTP1B, α-glucosidase, and DPP-IV inhibitory activities of compounds 1-16 were evaluated at the molecular level. Among them, compounds 4, 7, and 10 showed moderate DPP-IV inhibitory activities with IC50 values of 20.81, 33.12, and 32.93 μM, respectively. Compounds 3, 4, 6, 11, 12, and 16 showed strong PTP1B inhibitory activities, with respective IC50 values of 7.62, 10.80, 0.92, 2.68, 9.77, and 24.17 μM compared with the IC50 value for the positive control (ursolic acid: IC50 = 1.21 μM). Compounds 2-7, 11, 12, 15, and 16 showed potent α-glucosidase inhibitory activities, with respective IC50 values of 8.70, 81.66, 35.11, 35.92, 7.99, 26.28, 11.28, 62.68, 44.32, and 70.12 μM. The positive control, acarbose, displayed an IC50 value of 175.84 μM. In the kinetic study for the PTP1B enzyme, compounds 6, 11, and 12 displayed competitive inhibition with Ki values of 3.20, 8.56, and 5.86 μM, respectively. Compounds 3, 4, and 16 showed noncompetitive inhibition with Ki values of 18.75, 5.95, and 22.86 μM, respectively. Molecular docking study for the competitive inhibitors (6, 11, and 12) radically corroborates the binding affinities and inhibition of PTP1B enzymes. These results indicated that the leaves of Smilax china L. may contain compounds with anti-diabetic activity.
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Affiliation(s)
- Bing Tian Zhao
- College of Pharmacy, Catholic University of Daegu, Gyeongsan 38430, Republic of Korea
| | - Duc Dat Le
- College of Pharmacy, Catholic University of Daegu, Gyeongsan 38430, Republic of Korea
| | - Phi Hung Nguyen
- College of Pharmacy, Catholic University of Daegu, Gyeongsan 38430, Republic of Korea; Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology, 18-Hoang Quoc Viet, Hanoi, Vietnam
| | - Md Yousof Ali
- Department of Food Science & Nutrition, Pukyong National University, Busan 48513, Republic of Korea
| | - Jae-Sue Choi
- Department of Food Science & Nutrition, Pukyong National University, Busan 48513, Republic of Korea
| | - Byung Sun Min
- College of Pharmacy, Catholic University of Daegu, Gyeongsan 38430, Republic of Korea
| | - Heung Mook Shin
- Department of Physiology, College of Oriental Medicine, Dongguk University, Seoul 04620, Republic of Korea
| | - Hae Ik Rhee
- Department of Biotechnology, Kangwon National University, Chuncheon, Gangwon 24341, Republic of Korea
| | - Mi Hee Woo
- College of Pharmacy, Catholic University of Daegu, Gyeongsan 38430, Republic of Korea.
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13
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Grilo GA, Shaver PR, de Castro Brás LE. The Prospective Cardioprotective Effects of DPP-4 inhibition in the ischemic myocardium. J Mol Cell Cardiol 2016; 93:44-6. [PMID: 26916446 DOI: 10.1016/j.yjmcc.2016.01.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 01/22/2016] [Indexed: 12/30/2022]
Affiliation(s)
- Gabriel A Grilo
- The Brody School of Medicine, Department of Physiology, East Carolina University, 600 Moye Blvd, Greenville, NC 27834, United States
| | - Patti R Shaver
- The Brody School of Medicine, Department of Physiology, East Carolina University, 600 Moye Blvd, Greenville, NC 27834, United States
| | - Lisandra E de Castro Brás
- The Brody School of Medicine, Department of Physiology, East Carolina University, 600 Moye Blvd, Greenville, NC 27834, United States.
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14
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Skinner NEB, Wroblewski MS, Kirihara JA, Nelsestuen GL, Seaquist ER. Sitagliptin Results in a Decrease of Truncated Apolipoprotein C1. Diabetes Ther 2015. [PMID: 26198273 PMCID: PMC4575309 DOI: 10.1007/s13300-015-0123-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
UNLABELLED Apolipoprotein C1 (ApoC1) is a component of multiple lipoproteins where it performs a variety of roles in lipid metabolism and transport. ApoC1 exists as both full-length and truncated isoforms. Truncation of ApoC1 has been postulated to result from the action of dipeptidyl peptidase-4 (DPP-4), the target of a new class of diabetes drugs that includes sitagliptin phosphate. In this study, we sought to determine if oral administration of sitagliptin altered the proportion of ApoC1 isoforms circulating in humans. Results indicated a dramatic change in ApoC1 truncation, consistent with a high level of DPP-4 inhibition by sitagliptin. FUNDING University of Minnesota, Minneapolis, MN, USA.
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Affiliation(s)
- Nicole E B Skinner
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA
| | - Matthew S Wroblewski
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Julie A Kirihara
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Gary L Nelsestuen
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
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15
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Chung S, Dwabe S, Elshimali Y, Sukhija H, Aroh C, Vadgama JV. Identification of Novel Biomarkers for Metastatic Colorectal Cancer Using Angiogenesis-Antibody Array and Intracellular Signaling Array. PLoS One 2015; 10:e0134948. [PMID: 26258407 PMCID: PMC4530953 DOI: 10.1371/journal.pone.0134948] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 07/15/2015] [Indexed: 12/14/2022] Open
Abstract
Colorectal cancer (CRC) is one of the three leading causes for cancer mortality. CRC kills over 600,000 people annually worldwide. The most common cause of death from CRC is the metastasis to distant organs. However, biomarkers for CRC metastasis remain ill-defined. We compared primary and metastatic CRC cell lines for their angiogenesis-protein profiles and intracellular signaling profiles to identify novel biomarkers for CRC metastasis. To this end, we used primary and metastatic CRC cell lines as a model system and normal human colon cell line as a control. The angiogenesis profiles two isogenic CRC cell lines, SW480 and SW620, and HT-29 and T84 revealed that VEGF was upregulated in both SW620 and T84 whereas coagulation factor III, IGFBP-3, DPP IV, PDGF AA/AB, endothelin I and CXCL16 were downregulated specifically in metastatic cell lines. Furthermore, we found that TIMP-1, amphiregulin, endostatin, angiogenin were upregulated in SW620 whereas downregulated in T84. Angiogenin was downregulated in T84 and GM-CSF was also downregulated in SW620. To induce CRC cell metastasis, we treated cells with pro-inflammatory cytokine IL-6. Upon IL-6 treatment, epithelial-mesenchymal transition was induced in CRC cells. When DLD-1 and HT-29 cells were treated with IL-6; Akt, STAT3, AMPKα and Bad phosphorylation levels were increased. Interestingly, SW620 showed the same signal activation pattern with IL-6 treatment of HT-29 and DLD-1. Our data suggest that Akt, STAT3, AMPKα and Bad activation can be biomarkers for metastatic colorectal cancer. IL-6 treatment specifically reduced phosphorylation levels of EGFR, HER2 receptor, Insulin R and IGF-1R in receptor tyrosine kinase array study with HT-29. Taken together, we have identified novel biomarkers for metastatic CRC through the angiogenesis-antibody array and intracellular signaling array studies. Present study suggests that those novel biomarkers can be used as CRC prognosis biomarkers, and as potential targets for the metastatic CRC therapy.
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Affiliation(s)
- Seyung Chung
- Division of Cancer Research and Training, Department of Medicine, Charles R. Drew University of Medicine and Science, 1731 120 street, Los Angeles, California, 90059, United States of America
| | - Sami Dwabe
- Division of Cancer Research and Training, Department of Medicine, Charles R. Drew University of Medicine and Science, 1731 120 street, Los Angeles, California, 90059, United States of America
| | - Yayha Elshimali
- Division of Cancer Research and Training, Department of Medicine, Charles R. Drew University of Medicine and Science, 1731 120 street, Los Angeles, California, 90059, United States of America
| | - Hemlata Sukhija
- Division of Cancer Research and Training, Department of Medicine, Charles R. Drew University of Medicine and Science, 1731 120 street, Los Angeles, California, 90059, United States of America
| | - Clement Aroh
- Division of Cancer Research and Training, Department of Medicine, Charles R. Drew University of Medicine and Science, 1731 120 street, Los Angeles, California, 90059, United States of America
| | - Jaydutt V. Vadgama
- Division of Cancer Research and Training, Department of Medicine, Charles R. Drew University of Medicine and Science, 1731 120 street, Los Angeles, California, 90059, United States of America
- David Geffen UCLA School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- * E-mail:
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16
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Lacroix IME, Li-Chan ECY. Comparison of the susceptibility of porcine and human dipeptidyl-peptidase IV to inhibition by protein-derived peptides. Peptides 2015; 69:19-25. [PMID: 25828735 DOI: 10.1016/j.peptides.2015.03.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Revised: 03/19/2015] [Accepted: 03/19/2015] [Indexed: 01/20/2023]
Abstract
The enzyme dipeptidyl-peptidase IV (DPP-IV) is recognized to be a promising target for the management of type 2 diabetes. Over the last decade, numerous synthetic molecules and more recently, peptides from dietary proteins, have been reported to be able to inhibit DPP-IV activity. Most studies that have investigated the in vitro effect of these inhibitors have used porcine or human DPP-IV. Although structurally alike, it is unclear whether these two species display similar inhibition patterns. Therefore, the objective of this study was to compare the effects of protein-derived peptides on the activity of porcine and recombinant human DPP-IV. The two species showed different inhibition susceptibility to 43 of the 62 peptide sequences investigated. While 37 protein-derived peptides were more effective at inhibiting the porcine DPP-IV, only six caused a stronger inhibition of the activity of the human enzyme. Although the peptides WR, IPIQY and WCKDDQNPHS were found to be among the most potent inhibitors of both species, the inhibitory effect was greater on the porcine enzyme than on human DPP-IV (αKi or Ki=11.5, 13.4, 13.3 μM and 31.4, 28.2, 75.0 μM for porcine and human DPP-IV, respectively). Investigation into the mode of action of the most effective inhibitory peptides revealed that both species were inhibited in a similar manner by short fragments (≤5 amino acid residues), but that some of the longer peptides acted differently on the enzymes. This study shows that porcine DPP-IV is generally inhibited with greater potency by protein-derived peptides than is the human enzyme.
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Affiliation(s)
- Isabelle M E Lacroix
- The University of British Columbia, Faculty of Land & Food Systems, Food Nutrition & Health Program, 2205 East Mall, Vancouver, BC, Canada V6T 1Z4
| | - Eunice C Y Li-Chan
- The University of British Columbia, Faculty of Land & Food Systems, Food Nutrition & Health Program, 2205 East Mall, Vancouver, BC, Canada V6T 1Z4.
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17
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Uversky VN. The intrinsic disorder alphabet. III. Dual personality of serine. INTRINSICALLY DISORDERED PROTEINS 2015; 3:e1027032. [PMID: 28232888 DOI: 10.1080/21690707.2015.1027032] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 02/16/2015] [Accepted: 03/02/2015] [Indexed: 12/23/2022]
Abstract
Proteins are natural polypeptides consisting of 20 major amino acid residues, content and order of which in a given amino acid sequence defines the ability of a related protein to fold into unique functional state or to stay intrinsically disordered. Amino acid sequences code for both foldable (ordered) proteins/domains and for intrinsically disordered proteins (IDPs) and IDP regions (IDPRs), but these sequence codes are dramatically different. This difference starts with a very general property of the corresponding amino acid sequences, namely, their compositions. IDPs/IDPRs are enriched in specific disorder-promoting residues, whereas amino acid sequences of ordered proteins/domains typically contain more order-promoting residues. Therefore, the relative abundances of various amino acids in ordered and disordered proteins can be used to scale amino acids according to their disorder promoting potentials. This review continues a series of publications on the roles of different amino acids in defining the phenomenon of protein intrinsic disorder and represents serine, which is the third most disorder-promoting residue. Similar to previous publications, this review represents some physico-chemical properties of serine and the roles of this residue in structures and functions of ordered proteins, describes major posttranslational modifications tailored to serine, and finally gives an overview of roles of serine in structure and functions of intrinsically disordered proteins.
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Affiliation(s)
- Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer Research Institute; Morsani College of Medicine, University of South Florida; Tampa, FL USA; Biology Department; Faculty of Science, King Abdulaziz University; Jeddah, Kingdom of Saudi Arabia; Institute for Biological Instrumentation, Russian Academy of Sciences; Pushchino, Moscow Region, Russia; Laboratory of Structural Dynamics, Stability and Folding of Proteins; Institute of Cytology, Russian Academy of Sciences; St. Petersburg, Russia
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18
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Ruan Y, Shen L, Zou Y, Qi Z, Yin J, Jiang J, Guo L, He L, Chen Z, Tang Z, Qin S. Comparative genome analysis of Prevotella intermedia strain isolated from infected root canal reveals features related to pathogenicity and adaptation. BMC Genomics 2015; 16:122. [PMID: 25765460 PMCID: PMC4349605 DOI: 10.1186/s12864-015-1272-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Accepted: 01/22/2015] [Indexed: 01/10/2023] Open
Abstract
Background Many species of the genus Prevotella are pathogens that cause oral diseases. Prevotella intermedia is known to cause various oral disorders e.g. periodontal disease, periapical periodontitis and noma as well as colonize in the respiratory tract and be associated with cystic fibrosis and chronic bronchitis. It is of clinical significance to identify the main drive of its various adaptation and pathogenicity. In order to explore the intra-species genetic differences among strains of Prevotella intermedia of different niches, we isolated a strain Prevotella intermedia ZT from the infected root canal of a Chinese patient with periapical periodontitis and gained a draft genome sequence. We annotated the genome and compared it with the genomes of other taxa in the genus Prevotella. Results The raw data set, consisting of approximately 65X-coverage reads, was trimmed and assembled into contigs from which 2165 ORFs were predicted. The comparison of the Prevotella intermedia ZT genome sequence with the published genome sequence of Prevotella intermedia 17 and Prevotella intermedia ATCC25611 revealed that ~14% of the genes were strain-specific. The Preveotella intermedia strains share a set of conserved genes contributing to its adaptation and pathogenic and possess strain-specific genes especially those involved in adhesion and secreting bacteriocin. The Prevotella intermedia ZT shares similar gene content with other taxa of genus Prevotella. The genomes of the genus Prevotella is highly dynamic with relative conserved parts: on average, about half of the genes in one Prevotella genome were not included in another genome of the different Prevotella species. The degree of conservation varied with different pathways: the ability of amino acid biosynthesis varied greatly with species but the pathway of cell wall components biosynthesis were nearly constant. Phylogenetic tree shows that the taxa from different niches are scarcely distributed among clades. Conclusions Prevotella intermedia ZT belongs to a genus marked with highly dynamic genomes. The specific genes of Prevotella intermedia indicate that adhesion, competing with surrounding microbes and horizontal gene transfer are the main drive of the evolution of Prevotella intermedia. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1272-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yunfeng Ruan
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders(Ministry of Education, Shanghai Jiao Tong University, 1954 Huashang Road, Shanghai, 200030, China. .,Shanghai Institutes of Pilot Genomics and Human Health, Shanghai, 200030, China.
| | - Lu Shen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders(Ministry of Education, Shanghai Jiao Tong University, 1954 Huashang Road, Shanghai, 200030, China. .,Shanghai Institutes of Pilot Genomics and Human Health, Shanghai, 200030, China.
| | - Yan Zou
- Department of Endodontics, 9th People's Hospital, Shanghai JiaoTong University, School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai, 200011, China.
| | - Zhengnan Qi
- Department of Endodontics, 9th People's Hospital, Shanghai JiaoTong University, School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai, 200011, China.
| | - Jun Yin
- Department of Endodontics, 9th People's Hospital, Shanghai JiaoTong University, School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai, 200011, China.
| | - Jie Jiang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders(Ministry of Education, Shanghai Jiao Tong University, 1954 Huashang Road, Shanghai, 200030, China.
| | - Liang Guo
- The Fourth Hospital of Jinan City; Taishan Medical College, Jinan, 250031, China.
| | - Lin He
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders(Ministry of Education, Shanghai Jiao Tong University, 1954 Huashang Road, Shanghai, 200030, China. .,Shanghai Institutes of Pilot Genomics and Human Health, Shanghai, 200030, China.
| | - Zijiang Chen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders(Ministry of Education, Shanghai Jiao Tong University, 1954 Huashang Road, Shanghai, 200030, China. .,Center for Reproductive Medicine, Shandong Provincial Hospital, Shandong University, Jinan, Shandong, China.
| | - Zisheng Tang
- Department of Endodontics, 9th People's Hospital, Shanghai JiaoTong University, School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai, 200011, China.
| | - Shengying Qin
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders(Ministry of Education, Shanghai Jiao Tong University, 1954 Huashang Road, Shanghai, 200030, China. .,Shanghai Institutes of Pilot Genomics and Human Health, Shanghai, 200030, China.
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19
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Kim HY, Hwang JI, Moon MJ, Seong JY. A Novel Long-Acting Glucagon-Like Peptide-1 Agonist with Improved Efficacy in Insulin Secretion and β-Cell Growth. Endocrinol Metab (Seoul) 2014; 29:320-7. [PMID: 25309791 PMCID: PMC4192806 DOI: 10.3803/enm.2014.29.3.320] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 12/04/2013] [Accepted: 12/06/2013] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Glucagon-like peptide-1 (GLP-1) is an incretin hormone produced by cleavage of proglucagon in intestinal L-cells. In the pancreas, GLP-1 stimulates post-prandial insulin secretion, promotes insulin biosynthesis, and improves insulin sensitivity. Because of its insulinotropic activity, GLP-1 has been considered a good candidate drug for treatment of diabetes mellitus. However, clinical use of GLP-1 has been limited by its short half-life, as a result of rapid degradation by dipeptidyl peptidase-IV (DPP-IV). METHODS We designed a novel GLP-1 analog, Xenopus GLP-1 (xGLP)-E4. The Ala residue in the second position of xGLP was replaced with a Ser residue to increase the half-life in the body. The C-terminal tail of exendin-4 was added to enhance the binding affinity for the GLP-1 receptor (GLP1R). The potency of GLP-1 and its analogs was determined by luciferase assay. The stability of GLP1R agonists was evaluated by determining the activity of agonists that had been preincubated in the presence of fetal bovine serum, which contains innate DPP-IV activity. The effects of xGLP-E4 on insulin secretion and β-cell growth were investigated using insulin enzyme-linked immunosorbent assay and cell counting. RESULTS xGLP-E4 exhibited improved stability against DPP-IV activity and increased potency to GLP1R, compared with GLP-1. An increase in glucose-dependent insulin secretion was observed in xGLP-E4-treated pancreatic β-cells. The effect of xGLP-E4 on β-cell growth was greater than that of GLP-1. CONCLUSION We developed a novel GLP-1 analog, xGLP-E4, that shows prolonged longevity and improved efficacy. This analog is a potential candidate for treatment of type 2 diabetes.
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Affiliation(s)
- Hee Young Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea
| | - Jong-Ik Hwang
- Korea University Graduate School of Medicine, Seoul, Korea
| | - Mi Jin Moon
- Korea University Graduate School of Medicine, Seoul, Korea
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20
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Shu C, Ge H, Song M, Chen JH, Zhou H, Qi Q, Wang F, Ma X, Yang X, Zhang G, Ding Y, Zhou D, Peng P, Shih CK, Xu J, Wu F. Discovery of Imigliptin, a Novel Selective DPP-4 Inhibitor for the Treatment of Type 2 Diabetes. ACS Med Chem Lett 2014; 5:921-6. [PMID: 25147615 DOI: 10.1021/ml5001905] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Accepted: 06/09/2014] [Indexed: 11/29/2022] Open
Abstract
We report our discovery of a novel series of potent and selective dipeptidyl peptidase IV (DPP-4) inhibitors. Starting from a lead identified by scaffold-hopping approach, our discovery and development efforts were focused on exploring structure-activity relationships, optimizing pharmacokinetic profile, improving in vitro and in vivo efficacy, and evaluating safety profile. The selected candidate, Imigliptin, is now undergoing clinical trial.
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Affiliation(s)
- Chutian Shu
- Department
of Project Management, Medicinal Chemistry, Process, Pharmacology,
Drug Metabolism and Pharmacokenetics, Toxicology, XuanZhu Pharma, 2518
Tianchen Street, Jinan, Shandong, The People’s Republic of China
| | - Hu Ge
- School of Pharmaceutical Sciences & Institute of Human Virology, Sun Yat-Sen University, 132 East Circle Road at University City, Guangzhou, The People’s Republic of China
| | - Michael Song
- Department
of Project Management, Medicinal Chemistry, Process, Pharmacology,
Drug Metabolism and Pharmacokenetics, Toxicology, XuanZhu Pharma, 2518
Tianchen Street, Jinan, Shandong, The People’s Republic of China
| | - Jyun-hong Chen
- Department
of Project Management, Medicinal Chemistry, Process, Pharmacology,
Drug Metabolism and Pharmacokenetics, Toxicology, XuanZhu Pharma, 2518
Tianchen Street, Jinan, Shandong, The People’s Republic of China
| | - Huimin Zhou
- Department
of Project Management, Medicinal Chemistry, Process, Pharmacology,
Drug Metabolism and Pharmacokenetics, Toxicology, XuanZhu Pharma, 2518
Tianchen Street, Jinan, Shandong, The People’s Republic of China
| | - Qu Qi
- Department
of Project Management, Medicinal Chemistry, Process, Pharmacology,
Drug Metabolism and Pharmacokenetics, Toxicology, XuanZhu Pharma, 2518
Tianchen Street, Jinan, Shandong, The People’s Republic of China
| | - Feng Wang
- Department
of Project Management, Medicinal Chemistry, Process, Pharmacology,
Drug Metabolism and Pharmacokenetics, Toxicology, XuanZhu Pharma, 2518
Tianchen Street, Jinan, Shandong, The People’s Republic of China
| | - Xifeng Ma
- Department
of Project Management, Medicinal Chemistry, Process, Pharmacology,
Drug Metabolism and Pharmacokenetics, Toxicology, XuanZhu Pharma, 2518
Tianchen Street, Jinan, Shandong, The People’s Republic of China
| | - Xiaolei Yang
- Department
of Project Management, Medicinal Chemistry, Process, Pharmacology,
Drug Metabolism and Pharmacokenetics, Toxicology, XuanZhu Pharma, 2518
Tianchen Street, Jinan, Shandong, The People’s Republic of China
| | - Genyan Zhang
- Department
of Project Management, Medicinal Chemistry, Process, Pharmacology,
Drug Metabolism and Pharmacokenetics, Toxicology, XuanZhu Pharma, 2518
Tianchen Street, Jinan, Shandong, The People’s Republic of China
| | - Yanwei Ding
- Department
of Project Management, Medicinal Chemistry, Process, Pharmacology,
Drug Metabolism and Pharmacokenetics, Toxicology, XuanZhu Pharma, 2518
Tianchen Street, Jinan, Shandong, The People’s Republic of China
| | - Dapeng Zhou
- Department
of Project Management, Medicinal Chemistry, Process, Pharmacology,
Drug Metabolism and Pharmacokenetics, Toxicology, XuanZhu Pharma, 2518
Tianchen Street, Jinan, Shandong, The People’s Republic of China
| | - Peng Peng
- Department
of Project Management, Medicinal Chemistry, Process, Pharmacology,
Drug Metabolism and Pharmacokenetics, Toxicology, XuanZhu Pharma, 2518
Tianchen Street, Jinan, Shandong, The People’s Republic of China
| | - Cheng-kon Shih
- Department
of Project Management, Medicinal Chemistry, Process, Pharmacology,
Drug Metabolism and Pharmacokenetics, Toxicology, XuanZhu Pharma, 2518
Tianchen Street, Jinan, Shandong, The People’s Republic of China
- School of Pharmaceutical Sciences & Institute of Human Virology, Sun Yat-Sen University, 132 East Circle Road at University City, Guangzhou, The People’s Republic of China
| | - Jun Xu
- School of Pharmaceutical Sciences & Institute of Human Virology, Sun Yat-Sen University, 132 East Circle Road at University City, Guangzhou, The People’s Republic of China
| | - Frank Wu
- Department
of Project Management, Medicinal Chemistry, Process, Pharmacology,
Drug Metabolism and Pharmacokenetics, Toxicology, XuanZhu Pharma, 2518
Tianchen Street, Jinan, Shandong, The People’s Republic of China
- School of Pharmaceutical Sciences & Institute of Human Virology, Sun Yat-Sen University, 132 East Circle Road at University City, Guangzhou, The People’s Republic of China
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21
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Poncina N, Albiero M, Menegazzo L, Cappellari R, Avogaro A, Fadini GP. The dipeptidyl peptidase-4 inhibitor saxagliptin improves function of circulating pro-angiogenic cells from type 2 diabetic patients. Cardiovasc Diabetol 2014; 13:92. [PMID: 24886621 PMCID: PMC4033689 DOI: 10.1186/1475-2840-13-92] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 05/09/2014] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Type 2 diabetes (T2D) is associated with reduction and dysfunction of circulating pro-angiogenic cells (PACs). DPP-4 inhibitors, a class of oral agents for T2D, might possess pleiotropic vasculoprotective activities. Herein, we tested whether DPP-4 inhibition with Saxagliptin affects the function of circulating PACs from T2D and healthy subjects. METHODS PACs were isolated from T2D (n = 20) and healthy (n = 20) subjects. Gene expression, clonogenesis, proliferation, adhesion, migration and tubulisation were assessed in vitro by incubating PACs with or without Saxagliptin and SDF-1α. Stimulation of angiogenesis by circulating cells from T2D patients treated with Saxagliptin or other non-incretinergic drugs was assessed in vivo using animal models. RESULTS Soluble DPP-4 activity was predominant over cellular activity and was successfully inhibited by Saxagliptin. At baseline, T2D compared to healthy PACs contained less acLDL(+)Lectin(+) cells, and showed altered expression of genes related to adhesion and cell cycle regulation. This was reflected by impaired adhesion and clonogenesis/proliferative response of T2D PACs. Saxagliptin + SDF-1α improved adhesion and tube sustaining capacity of PACs from T2D patients. CD14+ PACs were more responsive to Saxagliptin than CD14- PACs. While Saxagliptin modestly reduced angiogenesis by mature endothelial cells, circulating PACs-progeny cells from T2D patients on Saxagliptin treatment displayed higher growth factor-inducible in vivo angiogenetic activity, compared to cells from T2D patients on non-incretinergic regimen. CONCLUSIONS Saxagliptin reverses PACs dysfunction associated with T2D in vitro and improves inducible angiogenesis by circulating cells in vivo. These data add knowledge to the potential pleiotropic cardiovascular effects of DPP-4 inhibition.
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Affiliation(s)
| | | | | | | | | | - Gian Paolo Fadini
- Venetian Institute of Molecular Medicine, University Hospital of Padova, Via Giustiniani, Padova 2, 35100, Italy.
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Leibovitz E, Gottlieb S, Goldenberg I, Gevrielov-Yusim N, Matetzky S, Gavish D. Sitagliptin pretreatment in diabetes patients presenting with acute coronary syndrome: results from the Acute Coronary Syndrome Israeli Survey (ACSIS). Cardiovasc Diabetol 2013; 12:53. [PMID: 23537430 PMCID: PMC3637090 DOI: 10.1186/1475-2840-12-53] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Accepted: 03/18/2013] [Indexed: 12/12/2022] Open
Abstract
Background Chronic treatment with currently available oral hypoglyemic medications may result in a differential effect on the clinical presentation of diabetic patients with acute coronary syndrome (ACS). Methods We evaluated presentation characteristics and the risk for in-hospital complications and 30-day major adverse cardiovascular events (MACE) among 445 patients with diabetes mellitus enrolled in the Acute Coronary Syndrome Israeli Survey (ACSIS) 2010. Patients were categorized into 3 groups according to glucose lowering medications at time of admission for ACS: 1) DPP 4 inhibitors (as monotherapy or in combination; DPP4i), 2) Metformin (monotherapy or in combination, excluding DPP4i) and 3) other oral hypoglycemics. Results Patients in the DPP4i group displayed similar baseline clinical characteristics to the other 2 groups, with the exception of a younger age and a lower frequency of prior coronary heart disease and chronic renal failure. Medical therapy with DPP4i was associated with a significantly lower in-hospital complication rate (post MI angina, re-infarction, pulmonary edema, infections, acute renal failure and better KILLIP class) (9.7%), lower rates of 30-day MACE (12.9%) and a shorter hospital stay (5.4 ± 3.8 days) as compared with patients treated with metformin (24.4%, 31.6% and 5.6 ± 5.0 days respectively) or other oral hypoglycemic drugs (45.5%, 48.5% and 7.5 ± 6.5 days respectively). Consistently, multivariate logistic regression modeling revealed that treatment with DPP4i was associated with a lower risk for in-hospital complications (OR = 0.129, p = 0.002) and 30-day MACE (OR = 0.157, p = 0.002) compared with other oral hypoglycaemic therapy. Conclusions Our data suggests that chronic treatment with DPP4i may have cardioprotective effects in diabetes patients presenting with acute coronary syndrome.
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Affiliation(s)
- Eyal Leibovitz
- Department of Internal Medicine A Wolfson Medical Center, Holon, Israel.
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23
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Kandasamy N, Lennox G, Annamalai AK, Maguire G, Adler AI. Sitagliptin in glutamic acid decarboxylase antibody-positive diabetes mellitus. Endocr Pract 2013; 18:e65-8. [PMID: 22297059 DOI: 10.4158/ep11340.cr] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To describe a case illustrating the use of sitagliptin, an inhibitor of dipeptidyl-peptidase-4 (DPP-4), in anti-glutamic acid decarboxylase antibody-positive diabetes mellitus in association with a rare ataxic variant of stiff person syndrome. METHODS We present our experience with use of the DPP-4 inhibitor sitagliptin for management of autoimmune diabetes in a elderly woman and highlight the association of diabetes with other autoimmune conditions. RESULTS A 68-year-old Japanese woman presented with poorly controlled "type 2" diabetes mellitus, cerebral palsy, cerebellar ataxia, and hypothyroidism. She complained of stiffness and spasms, which had resulted in multiple falls and immobility. Antidiabetic medications included gliclazide, rosiglitazone, and acarbose; various insulins had been tried but discontinued because they worsened her stiffness and spasms. Her hemoglobin A1c values remained above 9% despite maximal doses of the aforementioned orally administered hypoglycemic agents. After sitagliptin therapy was initiated, her hemoglobin A1c level decreased from 9.3% (78 mmol/mol) to 7.3% (56 mmol/mol) in 5 months. Investigations confirmed the presence of an ataxic variant of stiff person syndrome. On repeated testing 18 months later, her anti-glutamic acid decarboxylase antibody levels had declined by more than 85%. CONCLUSION Apart from the well-known mechanism of an increase in glucagonlike peptide-1, sitagliptin may exert its glucose-lowering effect by other mechanisms in patients with autoimmune diabetes. Further studies should be undertaken to address the effectiveness of DPP-4 inhibitors in non-type 2 diabetes.
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Affiliation(s)
- Narayanan Kandasamy
- Wolfson Diabetes and Endocrine Clinic, Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, UK
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24
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Tarantola E, Bertone V, Milanesi G, Capelli E, Ferrigno A, Neri D, Vairetti M, Barni S, Freitas I. Dipeptidylpeptidase--IV, a key enzyme for the degradation of incretins and neuropeptides: activity and expression in the liver of lean and obese rats. Eur J Histochem 2012; 56:e41. [PMID: 23361237 PMCID: PMC3567760 DOI: 10.4081/ejh.2012.e41] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 07/02/2012] [Accepted: 07/26/2012] [Indexed: 01/19/2023] Open
Abstract
Given the scarcity of donors, moderately fatty livers (FLs) are currently being considered as possible grafts for orthotopic liver transplantation (OLT), notwithstanding their poor tolerance to conventional cold preservation. The behaviour of parenchymal and sinusoidal liver cells during transplantation is being studied worldwide. Much less attention has been paid to the biliary tree, although this is considered the Achille's heel even of normal liver transplantation. To evaluate the response of the biliary compartment of FLs to the various phases of OLT reliable markers are necessary. Previously we demonstrated that Alkaline Phosphatase was scarcely active in bile canaliculi of FLs and thus ruled it out as a marker. As an alternative, dipeptidylpeptidase-IV (DPP-IV), was investigated. This ecto-peptidase plays an important role in glucose metabolism, rapidly inactivating insulin secreting hormones (incretins) that are important regulators of glucose metabolism. DPP-IV inhibitors are indeed used to treat Type II diabetes. Neuropeptides regulating bile transport and composition are further important substrates of DPP-IV in the enterohepatic axis. DPP-IV activity was investigated with an azo-coupling method in the liver of fatty Zucker rats (fa/fa), using as controls lean Zucker (fa/+) and normal Wistar rats. Protein expression was studied by immunofluorescence with the monoclonal antibody (clone 5E8). In Wistar rat liver, DPP-IV activity and expression were high in the whole biliary tree, and moderate in sinusoid endothelial cells, in agreement with the literature. Main substrates of DPP-IV in hepatocytes and cholangiocytes could be incretins GLP-1 and GIP, and neuropeptides such as vasoactive intestinal peptide (VIP) and substance P, suggesting that these substances are inactivated or modified through the biliary route. In lean Zucker rat liver the enzyme reaction and protein expression patterns were similar to those of Wistar rat. In obese rat liver the patterns of DPP-IV activity and expression in hepatocytes reflected the morphological alterations induced by steatosis as lipid-rich hepatocytes had scarce activity, located either in deformed bile canaliculi or in the sinusoidal and lateral domains of the plasma membrane. These findings suggest that bile canaliculi in steatotic cells have an impaired capacity to inactivate incretins and neuropeptides. Incretin and/or neuropeptide deregulation is indeed thought to play important roles in obesity and insulin-resistance. No alteration in enzyme activity and expression was found in the upper segments of the biliary tree of obese respect to lean Zucker and Wistar rats. In conclusion, this research demonstrates that DPP-IV is a promising in situ marker of biliary functionality not only of normal but also of fatty rats. The approach, initially devised to investigate the behaviour of the liver during the various phases of transplantation, appears to have a much higher potentiality as it could be further exploited to investigate any pathological or stressful conditions involving the biliary tract (i.e., metabolic syndrome and cholestasis) and the response of the biliary tract to therapy and/or to surgery.
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Affiliation(s)
- E Tarantola
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, Italy
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Merchant M, Monroe C, Falconi R. Dipeptidyl peptidase IV activity in the blood of the American alligator (Alligator mississippiensis). Comp Biochem Physiol B Biochem Mol Biol 2009; 154:341-5. [PMID: 19665574 DOI: 10.1016/j.cbpb.2009.07.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 07/08/2009] [Accepted: 07/30/2009] [Indexed: 11/27/2022]
Abstract
Dipeptidyl peptidase IV (DPP4) enzyme activity, associated with cell surface and soluble CD26, was measured in alligator plasma and whole blood. DPP4 activity was higher in whole blood than in the plasma, presumably due to the inclusion of both membrane-bound CD26 on the surface of T-cells and sCD26 in the plasma. The plasma DPP4 activity was measured within 5 min after the addition of the substrate, and maximal accumulation of product was reached at 120 min. Alligator whole blood DPP4 activity peaked at 120 min. In addition, the DPP4 activity in both plasma and whole blood was temperature-dependent, with moderate activities at lower temperatures (5-20 degrees C) and peak activity at 40 degrees C. Alligator plasma DPP4 displayed classical Michaelis-Menten kinetics, with a V(max) value of 267+/-9 nmol/min, and a K(m) of 21.1+/-1.9 microM, while these values were 286+/-14 nmol/min and 57.1+/-3.7 microM, respectively, for whole blood. The proteolytic activity was inhibited in a concentration-dependent manner by a specific DPP4 inhibitor, diprotin A, which indicates that the activity is probably due to the presence of DPP4. The significance of the presence of this activity in alligator blood is still unknown.
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Affiliation(s)
- Mark Merchant
- Department of Chemistry, McNeese State University, Lake Charles, LA 70609, USA.
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