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Equey T, Salamin O, Ponzetto F, Nicoli R, Kuuranne T, Saugy J, Saugy M, Aikin R, Baume N. Longitudinal Profiling of Endogenous Steroids in Blood Using the Athlete Biological Passport Approach. J Clin Endocrinol Metab 2023; 108:1937-1946. [PMID: 36794909 DOI: 10.1210/clinem/dgad085] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 02/02/2023] [Accepted: 02/09/2023] [Indexed: 02/17/2023]
Abstract
CONTEXT Detection of endogenous anabolic androgenic steroids (EAAS), like testosterone (T), as doping agents has been improved with the launch of the Steroidal Module of the Athlete Biological Passport (ABP) in urine samples. OBJECTIVE To target doping practices with EAAS, particularly in individuals with low level of biomarkers excreted in urine, by including new target compounds measured in blood. DESIGN T and T/androstenedione (T/A4) distributions were obtained from 4 years of anti-doping data and applied as priors to analyze individual profiles from 2 T administration studies in female and male subjects. SETTING Anti-doping laboratory. Elite athletes (n = 823) and male and female clinical trials subjects (n = 19 and 14, respectively). INTERVENTION(S) Two open-label administration studies were carried out. One involved a control phase period followed by patch and then oral T administration in male volunteers and the other followed female volunteers during 3 menstrual cycles with 28 days of daily transdermal T application during the second month. MAIN OUTCOME MEASURE(S) Serum samples were analyzed for T and A4 and the performance of a longitudinal ABP-based approach was evaluated for T and T/A4. RESULTS An ABP-based approach set at a 99% specificity flagged all female subjects during the transdermal T application period and 44% of subjects 3 days after the treatment. T showed the best sensitivity (74%) in response to transdermal T application in males. CONCLUSIONS Inclusion of T and T/A4 as markers in the Steroidal Module can improve the performance of the ABP to identify T transdermal application, particularly in females.
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Affiliation(s)
- Tristan Equey
- World Anti-Doping Agency (WADA), Montreal, Quebec H4Z 1B7, Canada
| | - Olivier Salamin
- Swiss Laboratory for Doping Analyses, University Center of Legal Medicine, Genève and Lausanne, Centre Hospitalier Universitaire Vaudois and University of Lausanne, 1066 Epalinges, Switzerland
- Research and Expertise in anti-Doping Sciences (REDs), Institute of Sport Sciences, University of Lausanne, 1015 Lausanne, Switzerland
| | - Federico Ponzetto
- Endocrinology, Diabetes and Metabolism, Department of Medical Sciences, City of Health and Science University Hospital, University of Turin, 10126 Turin, Italy
| | - Raul Nicoli
- Swiss Laboratory for Doping Analyses, University Center of Legal Medicine, Genève and Lausanne, Centre Hospitalier Universitaire Vaudois and University of Lausanne, 1066 Epalinges, Switzerland
| | - Tiia Kuuranne
- Swiss Laboratory for Doping Analyses, University Center of Legal Medicine, Genève and Lausanne, Centre Hospitalier Universitaire Vaudois and University of Lausanne, 1066 Epalinges, Switzerland
| | - Jonas Saugy
- Research and Expertise in anti-Doping Sciences (REDs), Institute of Sport Sciences, University of Lausanne, 1015 Lausanne, Switzerland
| | - Martial Saugy
- Research and Expertise in anti-Doping Sciences (REDs), Institute of Sport Sciences, University of Lausanne, 1015 Lausanne, Switzerland
| | - Reid Aikin
- World Anti-Doping Agency (WADA), Montreal, Quebec H4Z 1B7, Canada
| | - Norbert Baume
- World Anti-Doping Agency (WADA), Montreal, Quebec H4Z 1B7, Canada
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Diaz-Garzon J, Fernandez-Calle P, Aarsand AK, Sandberg S, Coskun A, Equey T, Aikin R, Soto AB. Long-Term Within- and Between-Subject Biological Variation Data of Hematological Parameters in Recreational Endurance Athletes. Clin Chem 2023; 69:500-509. [PMID: 36786725 DOI: 10.1093/clinchem/hvad006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 12/28/2022] [Indexed: 02/15/2023]
Abstract
BACKGROUND Hematological parameters have many applications in athletes, from monitoring health to uncovering blood doping. This study aimed to deliver biological variation (BV) estimates for 9 hematological parameters by a Biological Variation Data Critical Appraisal Checklist (BIVAC) design in a population of recreational endurance athletes and to assess the effect of self-reported exercise and health-related variables on BV. METHODS Samples were drawn from 30 triathletes monthly for 11 months and measured in duplicate for hematological measurands on an Advia 2120 analyzer (Siemens Healthineers). After outlier and homogeneity analysis, within-subject (CVI) and between-subject (CVG) BV estimates were delivered (CV-ANOVA and log-ANOVA, respectively) and a linear mixed model was applied to analyze the effect of exercise and other related variables on the BV estimates. RESULTS CVI estimates ranged from 1.3% (95%CI, 1.2-1.4) for mean corpuscular volume to 23.8% (95%CI, 21.6-26.3) for reticulocytes. Sex differences were observed for platelets and OFF-score. The CVI estimates were higher than those reported for the general population based on meta-analysis of eligible studies in the European Biological Variation Database, but 95%CI overlapped, except for reticulocytes, 23.9% (95%CI, 21.6-26.5) and 9.7% (95%CI, 6.4-11.0), respectively. Factors related to exercise and athletes' state of health did not appear to influence the BV estimates. CONCLUSIONS This is the first BIVAC-compliant study delivering BV estimates that can be applied to athlete populations performing high-level aerobic exercise. CVI estimates of most parameters were similar to the general population and were not influenced by exercise or athletes' state of health.
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Affiliation(s)
- Jorge Diaz-Garzon
- Laboratory Medicine Department, La Paz University Hospital, Madrid, Spain
| | | | - Aasne K Aarsand
- Norwegian Porphyria Centre, Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway.,Norwegian Organization for Quality Improvement of Laboratory Examinations (NOKLUS), Haraldsplass Deaconess Hospital, Bergen, Norway
| | - Sverre Sandberg
- Norwegian Porphyria Centre, Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway.,Norwegian Organization for Quality Improvement of Laboratory Examinations (NOKLUS), Haraldsplass Deaconess Hospital, Bergen, Norway.,Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
| | - Abdurrahman Coskun
- School of Medicine, Acibadem Mehmet Ali Aydınlar University, Istanbul, Turkey
| | - Tristan Equey
- Athlete Biological Passport, World Anti-Doping Agency (WADA), Montréal, Canada
| | - Reid Aikin
- Athlete Biological Passport, World Anti-Doping Agency (WADA), Montréal, Canada
| | - Antonio Buno Soto
- Laboratory Medicine Department, La Paz University Hospital, Madrid, Spain
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Equey T, Pastor A, de la Torre Fornell R, Thomas A, Giraud S, Thevis M, Kuuranne T, Baume N, Barroso O, Aikin R. Application of the Athlete Biological Passport Approach to the Detection of Growth Hormone Doping. J Clin Endocrinol Metab 2022; 107:649-659. [PMID: 34726230 DOI: 10.1210/clinem/dgab799] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Indexed: 11/19/2022]
Abstract
CONTEXT Because of its anabolic and lipolytic properties, growth hormone (GH) use is prohibited in sport. Two methods based on population-derived decision limits are currently used to detect human GH (hGH) abuse: the hGH Biomarkers Test and the Isoforms Differential Immunoassay. OBJECTIVE We tested the hypothesis that longitudinal profiling of hGH biomarkers through application of the Athlete Biological Passport (ABP) has the potential to flag hGH abuse. METHODS Insulin-like growth factor 1 (IGF-1) and procollagen III peptide (P-III-NP) distributions were obtained from 7 years of anti-doping data in elite athletes (n = 11 455) and applied as priors to analyze individual profiles from an hGH administration study in recreational athletes (n = 35). An open-label, randomized, single-site, placebo-controlled administration study was carried out with individuals randomly assigned to 4 arms: placebo, or 3 different doses of recombinant hGH. Serum samples were analyzed for IGF-1, P-III-NP, and hGH isoforms and the performance of a longitudinal, ABP-based approach was evaluated. RESULTS An ABP-based approach set at a 99% specificity level flagged 20/27 individuals receiving hGH treatment, including 17/27 individuals after cessation of the treatment. ABP sensitivity ranged from 12.5% to 71.4% across the hGH concentrations tested following 7 days of treatment, peaking at 57.1% to 100% after 21 days of treatment, and was maintained between 37.5% and 71.4% for the low and high dose groups 1 week after cessation of treatment. CONCLUSION These findings demonstrate that longitudinal profiling of hGH biomarkers can provide suitable performance characteristics for use in anti-doping programs.
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Affiliation(s)
- Tristan Equey
- World Anti-Doping Agency (WADA), Montreal, Quebec, Canada
| | - Antoni Pastor
- Integrative Pharmacology and Systems Neuroscience Research Group, Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
- Spanish Biomedical Research Centre in Physiopathology of Obesity and Nutrition (CIBEROBN), Madrid, Spain
- University Pompeu Fabra (CEXS-UPF), Barcelona, Spain
| | - Rafael de la Torre Fornell
- Integrative Pharmacology and Systems Neuroscience Research Group, Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
- Spanish Biomedical Research Centre in Physiopathology of Obesity and Nutrition (CIBEROBN), Madrid, Spain
- University Pompeu Fabra (CEXS-UPF), Barcelona, Spain
| | - Andreas Thomas
- Institute of Biochemistry, German Sport University Cologne, Cologne, Germany
| | - Sylvain Giraud
- Swiss Laboratory for Doping Analyses, University Center of Legal Medicine, Genève and Lausanne, Centre Hospitalier Universitaire Vaudois and University of Lausanne, 1066 Epalinges, Switzerland
| | - Mario Thevis
- Institute of Biochemistry, German Sport University Cologne, Cologne, Germany
| | - Tiia Kuuranne
- Swiss Laboratory for Doping Analyses, University Center of Legal Medicine, Genève and Lausanne, Centre Hospitalier Universitaire Vaudois and University of Lausanne, 1066 Epalinges, Switzerland
| | - Norbert Baume
- World Anti-Doping Agency (WADA), Montreal, Quebec, Canada
| | - Osquel Barroso
- World Anti-Doping Agency (WADA), Montreal, Quebec, Canada
| | - Reid Aikin
- World Anti-Doping Agency (WADA), Montreal, Quebec, Canada
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Esefeld M, Pastor A, de la Torre R, Barroso O, Aikin R, Sarwath H, Engelke R, Schmidt F, Suhre K. The Proteomic Signature of Recombinant Growth Hormone in Recreational Athletes. J Endocr Soc 2021; 5:bvab156. [PMID: 34765854 PMCID: PMC8577606 DOI: 10.1210/jendso/bvab156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVE Administration of human growth hormone (hGH) is prohibited in competitive sport and its detection in an athlete's sample triggers an adverse analytical finding. However, the biological processes that are modulated by recombinant hGH are not well characterized and associated blood serum proteins may constitute new biomarkers for hGH misuse. METHODS Thirty-five recreational athletes were enrolled in a study to investigate the time- and dose-dependent response of serum protein levels to recombinant hGH administration. Participants were randomly assigned to 4 groups, receiving 1 of 3 different doses of recombinant hGH or a placebo. Bio samples were collected at 22 time points over a period of 13 weeks, starting 4 weeks before treatment, during 3 weeks of treatment, and at 6 weeks' follow-up. A total of 749 serum samples were analyzed for 1305 protein markers using the SOMAscan proteomics platform. RESULTS We identified 66 proteins that significantly associated with recombinant hGH administration and dosage, including well known hGH targets, such as IGF1, but also previously unknown hGH-related proteins (eg, protease inhibitors, WFIKKN1, and chemokines, CCL2). Network analysis revealed changes in specific biological pathways, mainly related to the immune system and glucose metabolism. CONCLUSION Our analysis suggests that hGH administration affects biological processes more strongly than previously acknowledged. Some of the proteins were dysregulated even after hGH treatment and could potentially be developed into biomarkers for hGH misuse. Moreover, our findings suggest new roles for hGH-associated proteins in the etiology of hGH-related diseases and may indicate new risks that may be associated with hGH misuse.
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Affiliation(s)
- Max Esefeld
- Proteomics Core, Weill Cornell Medicine–Qatar, Qatar Foundation–Education City, Doha, Qatar
- Department of Transfusion Medicine, Institute for Immunology and Transfusion Medicine, University Medicine Greifswald, 17487 Greifswald, Germany
| | - Antoni Pastor
- Integrative Pharmacology and Systems Neuroscience Research Group. Hospital del Mar Medical Research Institute (IMIM), 08009 Barcelona, Spain
- Spanish Biomedical Research Centre in Physiopathology of Obesity and Nutrition (CIBEROBN), 28029 Madrid, Spain
- University Pompeu Fabra (CEXS-UPF)
| | - Rafael de la Torre
- Integrative Pharmacology and Systems Neuroscience Research Group. Hospital del Mar Medical Research Institute (IMIM), 08009 Barcelona, Spain
- Spanish Biomedical Research Centre in Physiopathology of Obesity and Nutrition (CIBEROBN), 28029 Madrid, Spain
- University Pompeu Fabra (CEXS-UPF)
| | - Osquel Barroso
- World Anti-Doping Agency, Montreal, Quebec H4Z 1B7, Canada
| | - Reid Aikin
- World Anti-Doping Agency, Montreal, Quebec H4Z 1B7, Canada
| | - Hina Sarwath
- Proteomics Core, Weill Cornell Medicine–Qatar, Qatar Foundation–Education City, Doha, Qatar
| | - Rudolf Engelke
- Proteomics Core, Weill Cornell Medicine–Qatar, Qatar Foundation–Education City, Doha, Qatar
| | - Frank Schmidt
- Proteomics Core, Weill Cornell Medicine–Qatar, Qatar Foundation–Education City, Doha, Qatar
| | - Karsten Suhre
- Bioinformatics Core, Weill Cornell Medicine-Qatar, Qatar Foundation–Education City, Doha, Qatar
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Equey T, Sletten C, Dehnes Y, D'Onofrio G, Brugnara C, Baume N, Aikin R. Standardization of reticulocyte counts in the athlete biological passport: A practical update. Int J Lab Hematol 2021; 44:112-117. [PMID: 34709714 DOI: 10.1111/ijlh.13732] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 09/24/2021] [Accepted: 09/27/2021] [Indexed: 11/29/2022]
Abstract
INTRODUCTION The athlete biological passport monitors blood variables over time to uncover blood doping. With the phasing in of a new series of blood analyzers, the Sysmex XN series, it was necessary to examine the comparability of results with the previously employed XT/XE series. A previous comparison between XN and XT/XE series suggested a small but significant bias between the two instruments in the measurements of RET%. Here, we examined the comparability of RET% on the XN and XT/XE platform using data collected over the first year since the transition. METHODS The comparability of results obtained from XN and XT/XE instruments was assessed using three datasets: (i) 767 blood samples measured on both instrument series in 22 WADA-accredited laboratories, (ii) 27 323 samples measured on either instrument across 31 laboratories, and (iii) 119 clinical samples and 110 anti-doping samples measured on both instruments in a single laboratory. RESULTS Analysis of the three datasets confirms the previous observation of a bias toward higher RET% values for samples measured on Sysmex XN instruments compared with the XT/XE series. Using data across a larger number of XN instruments and a larger athlete population, the current work suggests that the bias is proportional and slightly higher than previously observed across most of the range RET% values. CONCLUSION A model is proposed for the comparison of data across XN and XT/XE technologies whereby the instrument bias increases proportionally with RET% measured on Sysmex XN Series, but where the rate of increase is negatively related to IRF%.
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Affiliation(s)
| | - Camilla Sletten
- Norwegian Doping Control Laboratory, Department of Pharmacology, Oslo University Hospital, Oslo, Norway
| | - Yvette Dehnes
- Norwegian Doping Control Laboratory, Department of Pharmacology, Oslo University Hospital, Oslo, Norway
| | | | - Carlo Brugnara
- Department of Laboratory of Medicine, Boston Children's Hospital, & Department of Pathology, Harvard Medical School, Boston, Massachusetts, USA
| | | | - Reid Aikin
- World Anti-Doping Agency, Montreal, Quebec, Canada
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Naud J, Giraud S, Robinson N, Desharnais P, Ericsson M, Saugy M, Kuuranne T, Ayotte C, Boghosian T, Aikin R, Sottas P. Standardization of reticulocyte counts in the athlete biological passport. Int J Lab Hematol 2019; 41:387-391. [DOI: 10.1111/ijlh.12988] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 11/29/2018] [Accepted: 01/04/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Jean‐François Naud
- Laboratoire de contrôle du dopage de Montréal INRS Institut Armand‐Frappier Laval Canada
| | - Sylvain Giraud
- Laboratoire Suisse d'Analyse du Dopage Centre Hospitalier Universitaire Vaudois et Université de Lausanne Epalinges Switzerland
| | - Neil Robinson
- Laboratoire Suisse d'Analyse du Dopage Centre Hospitalier Universitaire Vaudois et Université de Lausanne Epalinges Switzerland
| | - Philippe Desharnais
- Laboratoire de contrôle du dopage de Montréal INRS Institut Armand‐Frappier Laval Canada
| | - Magnus Ericsson
- Doping Control Laboratory Karolinska University Hospital Stockholm Sweden
| | - Martial Saugy
- REDs ‐ Center for Research and Expertise in Anti‐Doping Sciences University of Lausanne Lausanne Switzerland
| | - Tiia Kuuranne
- Laboratoire Suisse d'Analyse du Dopage Centre Hospitalier Universitaire Vaudois et Université de Lausanne Epalinges Switzerland
| | - Christiane Ayotte
- Laboratoire de contrôle du dopage de Montréal INRS Institut Armand‐Frappier Laval Canada
| | | | - Reid Aikin
- World Anti‐Doping Agency Lausanne Switzerland
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Hopker J, Schumacher YO, Fedoruk M, Mørkeberg J, Bermon S, Iljukov S, Aikin R, Sottas PE. Athlete Performance Monitoring in Anti-Doping. Front Physiol 2018; 9:232. [PMID: 29636696 PMCID: PMC5881407 DOI: 10.3389/fphys.2018.00232] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 03/01/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- James Hopker
- Endurance Research Group, University of Kent, Chatham, United Kingdom
| | | | - Matthew Fedoruk
- United States Anti-Doping Agency, Colorado Springs, CO, United States
| | | | - Stéphane Bermon
- LMAHESS Nice, France and Monaco Institute of Sports Medicine and Surgery, University Cote d'Azur, Monaco, France
| | - Sergei Iljukov
- KIHU-Research Institute for Olympic Sports, Jyvaskyla, Finland
| | - Reid Aikin
- World Anti-Doping Agency, Lausanne, Switzerland
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Robinson N, Kirchbichler A, Banuls O, Mader M, Aikin R, Sottas PE, D'Onofrio G. Validation of a Blood Stability Score as an easy-to-use blood sample quality index. Int J Lab Hematol 2016; 38:685-693. [DOI: 10.1111/ijlh.12557] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 06/21/2016] [Indexed: 01/08/2023]
Affiliation(s)
- N. Robinson
- Swiss Laboratory for Doping Analyses; University Center of Legal Medicine, Lausanne and Geneva; Centre Hospitalier Universitaire Vaudois and University of Lausanne; Epalinges, VD Switzerland
| | | | - O. Banuls
- Cycling Anti-Doping Foundation; Aigle Switzerland
| | - M. Mader
- Nationale Anti-Doping Agentur Austria; Vienna Austria
| | - R. Aikin
- World Anti-Doping Agency; Lausanne Switzerland
| | | | - G. D'Onofrio
- Research Center for Automated Methods in Hematology; Catholic University of Sacred Hearth; Rome Italy
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Bhat M, Skill N, Marcus V, Deschenes M, Tan X, Bouteaud J, Negi S, Awan Z, Aikin R, Kwan J, Amre R, Tabaries S, Hassanain M, Seidah NG, Maluccio M, Siegel P, Metrakos P. Decreased PCSK9 expression in human hepatocellular carcinoma. BMC Gastroenterol 2015; 15:176. [PMID: 26674961 PMCID: PMC4682218 DOI: 10.1186/s12876-015-0371-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 10/08/2015] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND The management of hepatocellular carcinoma (HCC) is limited by the lack of adequate screening biomarkers and chemotherapy. In response, there has been much interest in tumor metabolism as a therapeutic target. PCSK9 stimulates internalization of the LDL-receptor, decreases cholesterol uptake into hepatocytes and affects liver regeneration. Thus, we investigated whether PCSK9 expression is altered in HCC, influencing its ability to harness cholesterol metabolism. METHODS Thirty-nine patients undergoing partial hepatectomy or liver transplantation for HCC were consented for use of HCC tissue to construct a tissue microarray (TMA). The TMA was immunostained for PCSK9. Imagescope software was used to objectively determine staining, and assess for pathological and clinical correlations. PCSK9 and LDL receptor mRNA levels in flash-frozen HCC and adjacent liver tissue were determined by quantitative RT-PCR. Serum PCSK9 levels were determined by ELISA. RESULTS By immunohistochemistry, there was significantly lower expression of PCSK9 in HCC as compared to adjacent cirrhosis (p-value < 0.0001, wilcoxon signed-rank test). Significantly greater staining of PCSK9 was present in cirrhosis compared to HCC (p value <0.0001), and positivity (percentage of positive cells) was significantly greater in cirrhosis compared to HCC (p-value < 0.0001). Conversely, significantly higher expression of LDL-R was present in HCC as compared to the adjacent cirrhosis (p-value < 0.0001). There was no significant correlation of PCSK9 staining with grade of tumor, but there were significant correlations between PCSK9 staining and stage of fibrosis, according to spearman correlation test. PCSK9 mRNA levels were relatively less abundant within HCC compared to adjacent liver tissue (p-value =0.08) and normal control tissue (p-value =0.02). In contrast, serum PCSK9 levels were significantly increased among patients with HCC compared to those with chronic liver disease without HCC (p-value =0.029). LDL receptor mRNA was consistantly greater in HCC when compared to normal control tissue (p-value = 0.06) and, in general, was significantly greater in HCC when compared to adjacent liver (p-value = 0.04). CONCLUSIONS The decreased expression of PCSK9 and conversely increased LDL-R expression in HCC suggests that HCC modulates its local microenvironment to enable a constant energy supply. Larger-scale studies should be conducted to determine whether PCSK9 could be a therapeutic target for HCC.
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Affiliation(s)
- Mamatha Bhat
- Division of Gastroenterology, McGill University Health Centre, 687 Pine Avenue West, Montreal, H3A1A1, Canada.
| | - Nicolas Skill
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA.
| | - Victoria Marcus
- Department of Pathology, McGill University Health Centre, Montreal, QC, Canada.
| | - Marc Deschenes
- Division of Gastroenterology, McGill University Health Centre, 687 Pine Avenue West, Montreal, H3A1A1, Canada.
| | - Xianming Tan
- Biostatistics Core Facility, Research Institute, McGill University Health Centre, Montreal, QC, Canada.
| | - Jeanne Bouteaud
- Hepatopancreatobiliary and Multi-Organ Transplant Surgery, McGill University Health Centre, Montreal, QC, Canada.
| | - Sarita Negi
- Hepatopancreatobiliary and Multi-Organ Transplant Surgery, McGill University Health Centre, Montreal, QC, Canada.
| | - Zuhier Awan
- Department of Medical Biochemistry, King Abdulaziz University, Jeddah, Saudi Arabia.
| | - Reid Aikin
- Hepatopancreatobiliary and Multi-Organ Transplant Surgery, McGill University Health Centre, Montreal, QC, Canada.
| | - Janet Kwan
- Hepatopancreatobiliary and Multi-Organ Transplant Surgery, McGill University Health Centre, Montreal, QC, Canada.
| | - Ramila Amre
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA.
| | - Sebastien Tabaries
- Department of Medicine, Goodman Cancer Research Centre, Montreal, QC, Canada.
| | - Mazen Hassanain
- Department of Pathology, McGill University Health Centre, Montreal, QC, Canada.
- Department of Surgery, King Saud University, Riyadh, Saudi Arabia.
| | - Nabil G Seidah
- Department of Medical Biochemistry, King Abdulaziz University, Jeddah, Saudi Arabia.
| | - Mary Maluccio
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA.
| | - Peter Siegel
- Department of Medicine, Goodman Cancer Research Centre, Montreal, QC, Canada.
| | - Peter Metrakos
- Department of Pathology, McGill University Health Centre, Montreal, QC, Canada.
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Affiliation(s)
- Reid Aikin
- Department of Surgery, McGill University; The Research Institute of the McGill University Health Centre; and Lady Davis Institute of the Jewish General Hospital, McGill University, Montreal, Quebec, Canada
| | - Lawrence Rosenberg
- Department of Surgery, McGill University; The Research Institute of the McGill University Health Centre; and Lady Davis Institute of the Jewish General Hospital, McGill University, Montreal, Quebec, Canada
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Aikin R, Cervantes A, D'Angelo G, Ruel L, Lacas-Gervais S, Schaub S, Thérond P. A genome-wide RNAi screen identifies regulators of cholesterol-modified hedgehog secretion in Drosophila. PLoS One 2012; 7:e33665. [PMID: 22432040 PMCID: PMC3303847 DOI: 10.1371/journal.pone.0033665] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Accepted: 02/14/2012] [Indexed: 12/12/2022] Open
Abstract
Hedgehog (Hh) proteins are secreted molecules that function as organizers in animal development. In addition to being palmitoylated, Hh is the only metazoan protein known to possess a covalently-linked cholesterol moiety. The absence of either modification severely disrupts the organization of numerous tissues during development. It is currently not known how lipid-modified Hh is secreted and released from producing cells. We have performed a genome-wide RNAi screen in Drosophila melanogaster cells to identify regulators of Hh secretion. We found that cholesterol-modified Hh secretion is strongly dependent on coat protein complex I (COPI) but not COPII vesicles, suggesting that cholesterol modification alters the movement of Hh through the early secretory pathway. We provide evidence that both proteolysis and cholesterol modification are necessary for the efficient trafficking of Hh through the ER and Golgi. Finally, we identified several putative regulators of protein secretion and demonstrate a role for some of these genes in Hh and Wingless (Wg) morphogen secretion in vivo. These data open new perspectives for studying how morphogen secretion is regulated, as well as provide insight into regulation of lipid-modified protein secretion.
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Affiliation(s)
- Reid Aikin
- CNRS UMR 7277, Inserm UMR 1091, Institut de Biologie Valrose (iBV), Centre de Biochimie, Nice, France
- Université de Nice-Sophia Antipolis, Nice, France
| | - Alexandra Cervantes
- CNRS UMR 7277, Inserm UMR 1091, Institut de Biologie Valrose (iBV), Centre de Biochimie, Nice, France
- Université de Nice-Sophia Antipolis, Nice, France
| | - Gisela D'Angelo
- CNRS UMR 7277, Inserm UMR 1091, Institut de Biologie Valrose (iBV), Centre de Biochimie, Nice, France
- Université de Nice-Sophia Antipolis, Nice, France
| | - Laurent Ruel
- CNRS UMR 7277, Inserm UMR 1091, Institut de Biologie Valrose (iBV), Centre de Biochimie, Nice, France
- Université de Nice-Sophia Antipolis, Nice, France
| | - Sandra Lacas-Gervais
- Centre Commun de Microscopie Appliquée (CCMA), Université de Nice-Sophia Antipolis, Nice, France
| | - Sébastien Schaub
- CNRS UMR 7277, Inserm UMR 1091, Institut de Biologie Valrose (iBV), Centre de Biochimie, Nice, France
- Université de Nice-Sophia Antipolis, Nice, France
| | - Pascal Thérond
- CNRS UMR 7277, Inserm UMR 1091, Institut de Biologie Valrose (iBV), Centre de Biochimie, Nice, France
- Université de Nice-Sophia Antipolis, Nice, France
- * E-mail:
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12
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Negi S, Jetha A, Aikin R, Hasilo C, Sladek R, Paraskevas S. Analysis of beta-cell gene expression reveals inflammatory signaling and evidence of dedifferentiation following human islet isolation and culture. PLoS One 2012; 7:e30415. [PMID: 22299040 PMCID: PMC3267725 DOI: 10.1371/journal.pone.0030415] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 12/15/2011] [Indexed: 12/20/2022] Open
Abstract
The stresses encountered during islet isolation and culture may have deleterious effects on beta-cell physiology. However, the biological response of human islet cells to isolation remains poorly characterized. A better understanding of the network of signaling pathways induced by islet isolation and culturing may lead to strategies aimed at improving islet graft survival and function. Laser capture microdissection (LCM) was used to extract beta-cell RNA from 1) intact pancreatic islets, 2) freshly isolated islets, 3) islets cultured for 3 days, and changes in gene expression were examined by microarray analysis. We identified a strong inflammatory response induced by islet isolation that continues during in-vitro culture manifested by upregulation of several cytokines and cytokine-receptors. The most highly upregulated gene, interleukin-8 (IL-8), was induced by 3.6-fold following islet isolation and 56-fold after 3 days in culture. Immunofluorescence studies showed that the majority of IL-8 was produced by beta-cells themselves. We also observed that several pancreas-specific transcription factors were down-regulated in cultured islets. Concordantly, several pancreatic progenitor cell-specific transcription factors like SOX4, SOX9, and ID2 were upregulated in cultured islets, suggesting progressive transformation of mature beta-cell phenotype toward an immature endocrine cell phenotype. Our findings suggest islet isolation and culture induces an inflammatory response and loss of the mature endocrine cell phenotype. A better understanding of the signals required to maintain a mature beta-cell phenotype may help improve the efficacy of islet transplantation.
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Affiliation(s)
- Sarita Negi
- Human Islet Transplantation Laboratory, McGill University Health Centre, Montreal, Quebec, Canada
- Department of Surgery, McGill University, Montreal, Quebec, Canada
| | - Arif Jetha
- Human Islet Transplantation Laboratory, McGill University Health Centre, Montreal, Quebec, Canada
- Department of Surgery, McGill University, Montreal, Quebec, Canada
| | - Reid Aikin
- Human Islet Transplantation Laboratory, McGill University Health Centre, Montreal, Quebec, Canada
- Department of Surgery, McGill University, Montreal, Quebec, Canada
| | - Craig Hasilo
- Human Islet Transplantation Laboratory, McGill University Health Centre, Montreal, Quebec, Canada
- Department of Surgery, McGill University, Montreal, Quebec, Canada
| | - Rob Sladek
- McGill University and Genome Quebec Innovation Centre, Montreal, Quebec, Canada
| | - Steven Paraskevas
- Human Islet Transplantation Laboratory, McGill University Health Centre, Montreal, Quebec, Canada
- Department of Surgery, McGill University, Montreal, Quebec, Canada
- * E-mail:
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13
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Negi S, Park SH, Jetha A, Aikin R, Tremblay M, Paraskevas S. Evidence of endoplasmic reticulum stress mediating cell death in transplanted human islets. Cell Transplant 2011; 21:889-900. [PMID: 22182941 DOI: 10.3727/096368911x603639] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
A key limitation to the success of islet transplantation is islet cell exhaustion and cell death during islet isolation and following transplantation. Endoplasmic reticulum (ER) stress has been identified as an important mechanism in the development of β-cell dysfunction, cell death, and diabetes. This study investigated the role of ER stress in islet loss during human islet isolation and posttransplantation in a diabetic athymic mouse model. Islets were isolated from human organ donor pancreata using intraductal enzymatic dissociation and continuous density gradient purification. ER stress mediators were assessed by Western blot and by RT-PCR. Caspase-3 activity was quantified by a bioluminescent peptide cleavage assay. Normal and streptozotocin-treated diabetic nude mice were transplanted with 2,000 IEQ of human islets under the kidney capsule and the grafts were harvested 3 or 28 days after transplantation. The grafts were analyzed for the presence for ER stress signals by immunohistochemistry. Isolated islets demonstrated higher levels of ER chaperone Bip, ER stress mediators eIF2α, ATF, spliced XBP-1, and CHOP, and also ER stress-associated apoptotic signals like JNK, caspase-3/7, and cleaved PARP. Donor pancreatic tissue did not show expression of any of these ER stress mediators. After transplantation, low expression of only protective ER stress mediators was evident in the grafts from the normal recipients. In contrast, both protective and apoptotic ER stress mediators were highly expressed in the grafts of hyperglycemic mice. ER stress mediators were induced during islet isolation and may contribute to islet apoptosis and cell death. Islet isolation activates ER stress and apoptotic pathways in isolated islets. Hyperglycemia may prolong this ER stress signal in engrafted islets, converting the protective aspects of the ER stress response to a proapoptotic response and thus contribute to deterioration of β-cell function and survival.
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Affiliation(s)
- Sarita Negi
- Human Islet Transplantation Laboratory, McGill University Health Centre, Montreal, Quebec, Canada
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14
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Grunnet LG, Aikin R, Tonnesen MF, Paraskevas S, Blaabjerg L, Størling J, Rosenberg L, Billestrup N, Maysinger D, Mandrup-Poulsen T. Proinflammatory cytokines activate the intrinsic apoptotic pathway in beta-cells. Diabetes 2009; 58:1807-15. [PMID: 19470609 PMCID: PMC2712790 DOI: 10.2337/db08-0178] [Citation(s) in RCA: 159] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
OBJECTIVE Proinflammatory cytokines are cytotoxic to beta-cells and have been implicated in the pathogenesis of type 1 diabetes and islet graft failure. The importance of the intrinsic mitochondrial apoptotic pathway in cytokine-induced beta-cell death is unclear. Here, cytokine activation of the intrinsic apoptotic pathway and the role of the two proapoptotic Bcl-2 proteins, Bad and Bax, were examined in beta-cells. RESEARCH DESIGN AND METHODS Human and rat islets and INS-1 cells were exposed to a combination of proinflammatory cytokines (interleukin-1beta, interferon-gamma, and/or tumor necrosis factor-alpha). Activation of Bad was determined by Ser136 dephosphorylation, mitochondrial stress by changes in mitochondrial metabolic activity and cytochrome c release, downstream apoptotic signaling by activation of caspase-9 and -3, and DNA fragmentation. The inhibitors FK506 and V5 were used to investigate the role of Bad and Bax activation, respectively. RESULTS We found that proinflammatory cytokines induced calcineurin-dependent dephosphorylation of Bad Ser136, mitochondrial stress, cytochrome c release, activation of caspase-9 and -3, and DNA fragmentation. Inhibition of Bad Ser136 dephosphorylation or Bax was found to inhibit cytokine-induced intrinsic proapoptotic signaling. CONCLUSIONS Our findings demonstrate that the intrinsic mitochondrial apoptotic pathway contributes significantly to cytokine-induced beta-cell death and suggest a functional role of calcineurin-mediated Bad Ser136 dephosphorylation and Bax activity in cytokine-induced apoptosis.
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Affiliation(s)
- Lars G. Grunnet
- Department of Translational Diabetology, Steno Diabetes Center, Gentofte, Denmark
- Core Unit for Medical Research Methodology, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- Corresponding author: Thomas Mandrup-Poulsen, , or Lars G. Grunnet,
| | - Reid Aikin
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
- Department of Surgery, McGill University, Montreal, Quebec, Canada
| | - Morten F. Tonnesen
- Department of Translational Diabetology, Steno Diabetes Center, Gentofte, Denmark
| | | | - Lykke Blaabjerg
- Department of Translational Diabetology, Steno Diabetes Center, Gentofte, Denmark
| | - Joachim Størling
- Department of Translational Diabetology, Steno Diabetes Center, Gentofte, Denmark
| | | | - Nils Billestrup
- Department of Translational Diabetology, Steno Diabetes Center, Gentofte, Denmark
| | - Dusica Maysinger
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - Thomas Mandrup-Poulsen
- Department of Translational Diabetology, Steno Diabetes Center, Gentofte, Denmark
- Core Unit for Medical Research Methodology, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- Corresponding author: Thomas Mandrup-Poulsen, , or Lars G. Grunnet,
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15
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Aikin R, Hanley S, Maysinger D, Lipsett M, Castellarin M, Paraskevas S, Rosenberg L. Autocrine insulin action activates Akt and increases survival of isolated human islets. Diabetologia 2006; 49:2900-9. [PMID: 17053882 DOI: 10.1007/s00125-006-0476-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2006] [Accepted: 09/08/2006] [Indexed: 12/31/2022]
Abstract
AIMS/HYPOTHESIS The phosphatidylinositol 3-kinase (PI3K)/Akt pathway plays a critical role in promoting the survival of pancreatic beta cells. Akt becomes activated in isolated human islets following overnight culture despite significant levels of cell death. The aim of the current study was to identify the cause of the observed increase in Akt phosphorylation in isolated islets. We hypothesised that a factor secreted by the islets in culture was acting in an autocrine manner to activate Akt. METHODS In order to identify the stimulus of the PI3K/Akt pathway in culture, we examined the effects of different culture conditions on Akt phosphorylation and islet survival during the immediate post-isolation period. RESULTS We demonstrated that islet-conditioned medium induced Akt phosphorylation in freshly isolated human islets, whereas frequent medium replacement decreased Akt phosphorylation. Following overnight culture, islet-conditioned medium contained significantly elevated levels of insulin, indicating that insulin may be responsible for the observed increase in Akt phosphorylation. Indeed, treatment with an anti-insulin antibody or with inhibitors of insulin receptor/IGF receptor 1 kinase activity suppressed Akt phosphorylation, leading to decreased islet survival. In addition, dispersion of islets into single cells also suppressed Akt phosphorylation and induced islet cell death, indicating that islet integrity is also required for maximal Akt phosphorylation. CONCLUSIONS/INTERPRETATION Our findings demonstrate that insulin acts in an autocrine manner to activate Akt and mediate the survival of isolated human islets. These findings provide new information on how culturing islets prior to transplantation may be beneficial to their survival by allowing for autocrine activation of the pro-survival Akt pathway.
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Affiliation(s)
- R Aikin
- Department of Surgery, McGill University, Montreal, QC, Canada
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16
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Lipsett M, Aikin R, Hanley S, Al-Maleek J, Laganiere S, Rosenburg L. Islet neogenesis: a potential therapeutic tool in type 1 diabetes. Int J Biochem Cell Biol 2006; 38:715-20. [PMID: 16607698 DOI: 10.1016/j.biocel.2006.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Current therapies for type 1 diabetes, including fastidious blood glucose monitoring and multiple daily insulin injections, are not sufficient to prevent complications of the disease. Though pancreas and possibly islet transplantation can prevent the progression of complications, the scarcity of donor organs limits widespread application of these approaches. Understanding the mechanisms of beta-cell mass expansion as well as the means to exploit these pathways has enabled researchers to develop new strategies to expand and maintain islet cell mass. Potential new therapeutic avenues include ex vivo islet expansion and improved viability of islets prior to implantation, as well as the endogenous expansion of beta-cell mass within the diabetic patient. Islet neogenesis, through stem cell activation and/or transdifferentiation of mature fully differentiated cells, has been proposed as a means of beta-cell mass expansion. Finally, any successful new therapy for type 1 diabetes via beta-cell mass expansion will require prevention of beta-cell death and maintenance of long-term endocrine function.
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Affiliation(s)
- Mark Lipsett
- Centre for Pancreatic Diseases at the McGill University Health Centre, Department of Surgery, McGill Uinversity, Montreal, Canada.
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Lipsett M, Aikin R, Castellarin M, Hanley S, Jamal AM, Laganiere S, Rosenberg L. Islet neogenesis: A potential therapeutic tool in type 1 diabetes. Int J Biochem Cell Biol 2006; 38:498-503. [PMID: 16216541 DOI: 10.1016/j.biocel.2005.08.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2005] [Revised: 08/11/2005] [Accepted: 08/24/2005] [Indexed: 10/25/2022]
Abstract
Current therapies for type 1 diabetes, including fastidious blood glucose monitoring and multiple daily insulin injections, are not sufficient to prevent complications of the disease. Though pancreas and possibly islet transplantation can prevent the progression of complications, the scarcity of donor organs limits widespread application of these approaches. Understanding the mechanisms of beta-cell mass expansion as well as the means to exploit these pathways has enabled researchers to develop new strategies to expand and maintain islet cell mass. Potential new therapeutic avenues include ex vivo islet expansion and improved viability of islets prior to implantation, as well as the endogenous expansion of beta-cell mass within the diabetic patient. Islet neogenesis, through stem cell activation and/or transdifferentiation of mature fully differentiated cells, has been proposed as a means of beta-cell mass expansion. Finally, any successful new therapy for type 1 diabetes via beta-cell mass expansion will require prevention of beta-cell death and maintenance of long-term endocrine function.
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Affiliation(s)
- Mark Lipsett
- Centre for Pancreatic Diseases at the McGill University Health Centre, Department of Surgery, McGill University, C9-128 Montreal General Hospital, 1650 Cedar Avenue, Montreal, Que., Canada.
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18
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Aikin R, Maysinger D, Rosenberg L. Cross-talk between phosphatidylinositol 3-kinase/AKT and c-jun NH2-terminal kinase mediates survival of isolated human islets. Endocrinology 2004; 145:4522-31. [PMID: 15242986 DOI: 10.1210/en.2004-0488] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Therapeutic strategies aimed at the inhibition of specific cell death mechanisms may increase islet yield and improve cell viability and function after routine isolation. The aim of the current study was to explore the possibility of AKT-JNK cross-talk in islets after isolation and the relevance of c-jun NH2-terminal kinases (JNK) suppression on islet survival. After routine isolation, increased AKT activity correlated with suppression of JNK activation, suggesting that they may be related events. Indeed, the increase in AKT activation after isolation correlated with suppression of apoptosis signal-regulating kinase 1 (ASK1), a kinase acting upstream of JNK, by phosphorylation at Ser83. We therefore examined whether modulators of phosphatidylinositol 3-kinase (PI3K)/AKT signaling affected JNK activation. PI3K inhibition led to increased JNK phosphorylation and islet cell death, which could be reversed by the specific JNK inhibitor SP600125. In addition, IGF-I suppressed cytokine-mediated JNK activation in a PI3K-dependent manner. We also demonstrate that inhibition of PI3K rendered islets more susceptible to cytokine-mediated cell death. SP600125 transiently protected islets from cytokine-mediated cell death, suggesting that JNK may not be necessary for cytokine-induced cell death. When administered immediately after isolation, SP600125 improved islet survival and function, even 48 h after removal of SP600125, suggesting that JNK inhibition by SP600125 may be a viable strategy for improving isolated islet survival. Taken together, these results demonstrate that PI3K/AKT suppresses the JNK pathway in islets, and this cross-talk represents an important antiapoptotic consequence of PI3K/AKT activation.
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Affiliation(s)
- Reid Aikin
- Department of Surgery, Montréal General Hospital, Room C9-128, 1650 Cedar Avenue, Montréal, Québec, Canada H3G 1A4
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Aikin R, Rosenberg L, Paraskevas S, Maysinger D. Inhibition of caspase-mediated PARP-1 cleavage results in increased necrosis in isolated islets of Langerhans. J Mol Med (Berl) 2004; 82:389-97. [PMID: 15105993 DOI: 10.1007/s00109-004-0540-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2003] [Accepted: 02/25/2004] [Indexed: 12/01/2022]
Abstract
The current procedure for isolation of islet cells from the pancreas for transplantation by enzymatic digestion is accompanied by significant islet cell loss. Therapeutic strategies aimed at the inhibition of islet cell damage could be expected to increase islet yield and improve cell viability, thereby making more efficient use of available donor tissue. The aim of the present work was to examine the effects of caspase and PARP-1 inhibition on islet survival. We demonstrate that following isolation, islets become increasingly necrotic and display a PARP-1 cleavage pattern typical of necrotic cells, characterized by the appearance of a 50 kDa cleavage product. Caspase inhibition using Z-VAD-fmk resulted in increased necrosis in both human and canine islets by a nicotinamide-sensitive mechanism. Necrosis was also induced by DEVD-fmk, but not by YVAD-cmk, indicating that only inhibitors of caspase-3 were able to cause necrosis. Moreover, increased mitochondrial depolarization was observed in islets following 72 h in culture, which correlated with increased expression of Bax. Mitochondrial depolarization was also visible in islets treated with both Z-VAD-fmk and nicotinamide, indicating that mitochondrial dysfunction may account for the necrotic-like death observed in the absence of PARP-1 and caspase activity. Our results demonstrate that inhibition of PARP-1 cleavage results in increased levels of PARP-1-mediated necrotic cell death, highlighting the importance of PARP-1 cleavage in assuring the execution of the apoptotic program. Taken together, these findings reveal the interdependence of necrosis and apoptosis in isolated islets, suggesting therapeutic strategies which target early events in cell death signaling in order to prevent multiple forms of islet cell death.
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Affiliation(s)
- Reid Aikin
- Department of Surgery, McGill University, Montreal General Hospital, 1650 Cedar Ave., Montreal, H3G 1A4, Canada
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20
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Paraskevas S, Aikin R, Maysinger D, Lakey JR, Cavanagh TJ, Agapitos D, Wang R, Rosenberg L. Modulation of JNK and p38 stress activated protein kinases in isolated islets of Langerhans: insulin as an autocrine survival signal. Ann Surg 2001; 233:124-33. [PMID: 11141234 PMCID: PMC1421175 DOI: 10.1097/00000658-200101000-00018] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE The objective of this study was to determine the effects of islet isolation and cytokine exposure on e-JUN NH2 terminal kinase (JNK) and p38 activation and whether insulin or the p38 inhibitor PD169316 could modify the response. SUMMARY BACKGROUND DATA Islet transplantation exposes the cells of the graft to a variety of stressful stimuli that could promote beta-cell death and lead to graft failure. METHODS Islets from canine (n = 12) and cadaveric human (n = 6) pancreata were isolated and purified. Islets were cultured in CMRL 1066 with and without 100 ng/ml insulin. The response to cytokine stimulation with tumor necrosis factor (TNF)alpha and IL-1 beta and the p38 inhibitor PD169316 was also observed. Islet lysates were analyzed by Western blotting for total and phosphorylated JNK and p38 content. Apoptosis was assessed by TdT-mediated dUTP nick end labeling (TUNEL) assay and by a specific cell death enzyme-linked immunosorbant assay (ELISA). RESULTS In unstimulated islets, JNK activity was highest immediately following isolation, declining over 3 days to a low baseline level. The activity of p38 was lowest immediately after isolation, increasing progressively with time. The addition of insulin resulted in a more rapid decline in JNK activity, as opposed to p38, which showed no decrease in phosphorylation in response to insulin. In the cytokine stimulation studies, IL-1 beta stimulated p38 activation in a dose dependent manner, while JNK was relatively unaffected. PD169316 (100 microg/ml) was able to inhibit p38 activation in response to the isolation procedure as well as cytokine stimulation. Apoptotic activity was highest 24 hours after isolation, and was significantly reduced when islets were maintained in insulin-supplemented medium. CONCLUSIONS Inhibition of the stress-activated protein kinase (SAPK) pathways may be important for the maintenance of islet cell survival following islet isolation for transplantation. This study supports an autocrine role of insulin in this process.
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Affiliation(s)
- S Paraskevas
- Departments of Surgery, the Montreal General Hospital Research Institute and McGill University, Montreal, Quebec, Canada
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21
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Aikin R, Rosenberg L, Maysinger D. Phosphatidylinositol 3-kinase signaling to Akt mediates survival in isolated canine islets of Langerhans. Biochem Biophys Res Commun 2000; 277:455-61. [PMID: 11032744 DOI: 10.1006/bbrc.2000.3664] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The isolation of islet cells from the pancreas by enzymatic digestion causes many of these cells to undergo apoptosis. The aim of this work was to investigate the role of phosphatidylinositol 3-kinase (PI3-K)/Akt signaling in mediating the survival of isolated islets. Insulin-like growth factor-1 (IGF-I) was examined as a potential culture media supplement that could rescue isolated islets from their apoptotic fate. Western blot analysis demonstrated that Akt phosphorylation peaks 20 h after routine islet isolation. PI3-K inhibition with wortmannin abolished both basal and IGF-I-mediated Akt phosphorylation. IGF-I did not increase survival of isolated islets under normal conditions but it did have a protective effect against cytokine (TNF-alpha, IL-1beta, INF-gamma)-mediated cell death. The protective effect of IGF-I against cytokine-stimulated apoptosis was blocked by wortmannin. In addition, inhibition of basal levels of PI3-K activity caused a 31% decrease in islet survival, as shown by MTT assay. These results demonstrate that the PI3-K/Akt pathway mediates survival of isolated islets of Langerhans.
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Affiliation(s)
- R Aikin
- Department of Surgery, McGill University, Montreal, Quebec, H3G 1A4, Canada
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22
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Paraskevas S, Aikin R, Maysinger D, Lakey JR, Cavanagh TJ, Hering B, Wang R, Rosenberg L. Activation and expression of ERK, JNK, and p38 MAP-kinases in isolated islets of Langerhans: implications for cultured islet survival. FEBS Lett 1999; 455:203-8. [PMID: 10437773 DOI: 10.1016/s0014-5793(99)00882-0] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Isolation and purification of islet cells exposes them to ischemic, osmotic and mechanical stresses. The objective of this study was to determine the roles of the MAP-kinases in islets immediately following isolation. During the first 48 h, activity of JNK1 and JNK2 declined markedly. Activity of p38 increased steadily with time in culture while extracellular signal regulated kinase (ERK) activity declined dramatically within 24 h post-isolation. High p38 activation relative to ERK activation immediately following isolation correlated with a decrease in islet survival after 36 h in culture. Absence and/or transiency of ERK signaling in conjunction with sustained activation of p38 pathway could be an important regulator of cell death in islets during and following their isolation by commonly employed procedures.
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Affiliation(s)
- S Paraskevas
- Department of Surgery, The Montreal General Hospital, Que., Canada
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