1
|
Van Simaeys D, De La Fuente A, Zilio S, Zoso A, Kuznetsova V, Alcazar O, Buchwald P, Grilli A, Caroli J, Bicciato S, Serafini P. RNA aptamers specific for transmembrane p24 trafficking protein 6 and Clusterin for the targeted delivery of imaging reagents and RNA therapeutics to human β cells. Nat Commun 2022; 13:1815. [PMID: 35383192 PMCID: PMC8983715 DOI: 10.1038/s41467-022-29377-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 03/08/2022] [Indexed: 12/20/2022] Open
Abstract
The ability to detect and target β cells in vivo can substantially refine how diabetes is studied and treated. However, the lack of specific probes still hampers a precise characterization of human β cell mass and the delivery of therapeutics in clinical settings. Here, we report the identification of two RNA aptamers that specifically and selectively recognize mouse and human β cells. The putative targets of the two aptamers are transmembrane p24 trafficking protein 6 (TMED6) and clusterin (CLUS). When given systemically in immune deficient mice, these aptamers recognize the human islet graft producing a fluorescent signal proportional to the number of human islets transplanted. These aptamers cross-react with endogenous mouse β cells and allow monitoring the rejection of mouse islet allografts. Finally, once conjugated to saRNA specific for X-linked inhibitor of apoptosis (XIAP), they can efficiently transfect non-dissociated human islets, prevent early graft loss, and improve the efficacy of human islet transplantation in immunodeficient in mice.
Collapse
Affiliation(s)
- Dimitri Van Simaeys
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Adriana De La Fuente
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Serena Zilio
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Alessia Zoso
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Victoria Kuznetsova
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Oscar Alcazar
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Peter Buchwald
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Andrea Grilli
- Center for Genome Research, Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Jimmy Caroli
- Center for Genome Research, Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Silvio Bicciato
- Center for Genome Research, Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Paolo Serafini
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL, USA. .,Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, USA. .,Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL, USA.
| |
Collapse
|
2
|
Lau H, Khosrawipour T, Li S, Alexander M, Frelkiewicz P, Labbé MK, Stieglitz S, Lakey JRT, Kielan W, Khosrawipour V. Exploring Insulin Production Following Alveolar Islet Transplantation (AIT). Int J Mol Sci 2021; 22:ijms221910185. [PMID: 34638521 PMCID: PMC8508311 DOI: 10.3390/ijms221910185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 09/11/2021] [Accepted: 09/16/2021] [Indexed: 11/29/2022] Open
Abstract
Recent studies have demonstrated the feasibility of islet implantation into the alveoli. However, until today, there are no data on islet behavior and morphology at their transplant site. This study is the first to investigate islet distribution as well insulin production at the implant site. Using an ex vivo postmortem swine model, porcine pancreatic islets were isolated and aerosolized into the lung using an endoscopic spray-catheter. Lung tissue was explanted and bronchial airways were surgically isolated and connected to a perfusor. Correct implantation was confirmed via histology. The purpose of using this new lung perfusion model was to measure static as well as dynamic insulin excretions following glucose stimulation. Alveolar islet implantation was confirmed after aerosolization. Over 82% of islets were correctly implanted into the intra-alveolar space. The medium contact area to the alveolar surface was estimated at 60 +/− 3% of the total islet surface. The new constructed lung perfusion model was technically feasible. Following static glucose stimulation, insulin secretion was detected, and dynamic glucose stimulation revealed a biphasic insulin secretion capacity during perfusion. Our data indicate that islets secrete insulin following implantation into the alveoli and display an adapted response to dynamic changes in glucose. These preliminary results are encouraging and mark a first step toward endoscopically assisted islet implantation in the lung.
Collapse
Affiliation(s)
- Hien Lau
- Department of Surgery, University of California, Irvine (UCI), Orange, CA 92868, USA; (M.A.); (J.R.T.L.); (V.K.)
- Correspondence: (H.L.); (T.K.)
| | - Tanja Khosrawipour
- Department of Surgery (A), University-Hospital Düsseldorf, Heinrich-Heine University, Moorenstrasse 5, D-40225 Duesseldorf, Germany
- Correspondence: (H.L.); (T.K.)
| | - Shiri Li
- Department of Surgery, Weill Medical College of Cornell University, New York, NY 10065, USA;
| | - Michael Alexander
- Department of Surgery, University of California, Irvine (UCI), Orange, CA 92868, USA; (M.A.); (J.R.T.L.); (V.K.)
| | - Piotr Frelkiewicz
- Center for Experimental Diagnostics and Biomedical Innovations, Wroclaw University of Environmental and Life Sciences, 50-375 Wroclaw, Poland;
| | - Maya Karine Labbé
- School of Dentistry, Wroclaw Medical University, 50-367 Wroclaw, Poland;
| | - Sven Stieglitz
- Department Pulmonary Medicine, Petrus-Hospital Wuppertal, University of Witten-Herdecke, D-42283 Wuppertal, Germany;
| | - Jonathan Robert Todd Lakey
- Department of Surgery, University of California, Irvine (UCI), Orange, CA 92868, USA; (M.A.); (J.R.T.L.); (V.K.)
| | - Wojciech Kielan
- 2nd Department of General Surgery and Surgical Oncology, Wroclaw Medical University, 50-556 Wroclaw, Poland;
| | - Veria Khosrawipour
- Department of Surgery, University of California, Irvine (UCI), Orange, CA 92868, USA; (M.A.); (J.R.T.L.); (V.K.)
- 2nd Department of General Surgery and Surgical Oncology, Wroclaw Medical University, 50-556 Wroclaw, Poland;
| |
Collapse
|
3
|
Lau H, Corrales N, Rodriguez S, Luong C, Zaldivar F, Alexander M, Lakey JRT. An islet maturation media to improve the development of young porcine islets during in vitro culture. Islets 2020; 12:41-58. [PMID: 32459554 PMCID: PMC7527017 DOI: 10.1080/19382014.2020.1750933] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND The use of pancreata from pre-weaned piglets has the potential to serve as an unlimited alternative source of islets for clinical xenotransplantation. As pre-weaned porcine islets (PPIs) are immature and require prolonged culture, we developed an islet maturation media (IMM) and evaluated its effect on improving the quantity and quality of PPIs over 14 days of culture. METHODS PPIs were isolated from the pancreata of pre-weaned Yorkshire piglets (8-15 days old). Each independent islet isolation was divided for culture in either control Ham's F-10 media (n = 5) or IMM (n = 5) for 14 days. On day 3, 7 and 14 of culture, islets were assessed for islet yield, isolation index, viability, insulin content, endocrine cellular composition, differentiation of beta cells, and insulin secretion during glucose stimulation. RESULTS In comparison to control islets, culturing PPIs in IMM significantly increased islet yield. PPIs cultured in IMM also maintained a stable isolation index and viability throughout 14 days of culture. The insulin content, endocrine cellular composition, and differentiation of beta cells were significantly improved in PPIs cultured in IMM, which subsequently augmented their insulin secretory capacity in response to glucose challenge compared to control islets. CONCLUSIONS Culturing PPIs in IMM increases islet yield, isolation index, viability, insulin content, endocrine cellular composition, differentiation of endocrine progenitor cells toward beta cells, and insulin secretion. Due to the improved islet quantity and quality after in vitro culture, the use of IMM in the culture of PPIs will assist to advance the outcomes of clinical islet xenotransplantation.
Collapse
Affiliation(s)
- Hien Lau
- Department of Surgery, University of California, Irvine, Orange, CA, USA
| | - Nicole Corrales
- Department of Surgery, University of California, Irvine, Orange, CA, USA
| | - Samuel Rodriguez
- Department of Surgery, University of California, Irvine, Orange, CA, USA
| | - Colleen Luong
- Department of Surgery, University of California, Irvine, Orange, CA, USA
| | - Frank Zaldivar
- Department of Pediatrics, Pediatric Exercise and Genomics Research Center, University of California, Irvine, Irvine, CA, USA
| | - Michael Alexander
- Department of Surgery, University of California, Irvine, Orange, CA, USA
| | - Jonathan R. T. Lakey
- Department of Surgery, University of California, Irvine, Orange, CA, USA
- Department of Biomedical Engineering, University of California Irvine, Irvine, CA, USA
- CONTACT Jonathan R. T. Lakey Department of Surgery and Biomedical Engineering, Clinical Islet Program, 333 City Blvd West, Suite 1600, Orange, CA92868, USA
| |
Collapse
|
4
|
Oxygenation strategies for encapsulated islet and beta cell transplants. Adv Drug Deliv Rev 2019; 139:139-156. [PMID: 31077781 DOI: 10.1016/j.addr.2019.05.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 04/19/2019] [Accepted: 05/04/2019] [Indexed: 02/06/2023]
Abstract
Human allogeneic islet transplantation (ITx) is emerging as a promising treatment option for qualified patients with type 1 diabetes. However, widespread clinical application of allogeneic ITx is hindered by two critical barriers: the need for systemic immunosuppression and the limited supply of human islet tissue. Biocompatible, retrievable immunoisolation devices containing glucose-responsive insulin-secreting tissue may address both critical barriers by enabling the more effective and efficient use of allogeneic islets without immunosuppression in the near-term, and ultimately the use of a cell source with a virtually unlimited supply, such as human stem cell-derived β-cells or xenogeneic (porcine) islets with minimal or no immunosuppression. However, even though encapsulation methods have been developed and immunoprotection has been successfully tested in small and large animal models and to a limited extent in proof-of-concept clinical studies, the effective use of encapsulation approaches to convincingly and consistently treat diabetes in humans has yet to be demonstrated. There is increasing consensus that inadequate oxygen supply is a major factor limiting their clinical translation and routine implementation. Poor oxygenation negatively affects cell viability and β-cell function, and the problem is exacerbated with the high-density seeding required for reasonably-sized clinical encapsulation devices. Approaches for enhanced oxygen delivery to encapsulated tissues in implantable devices are therefore being actively developed and tested. This review summarizes fundamental aspects of islet microarchitecture and β-cell physiology as well as encapsulation approaches highlighting the need for adequate oxygenation; it also evaluates existing and emerging approaches for enhanced oxygen delivery to encapsulation devices, particularly with the advent of β-cell sources from stem cells that may enable the large-scale application of this approach.
Collapse
|
5
|
Obach M, Hosseini-Tabatabaei A, Montane J, Wind K, Soukhatcheva G, Dai D, Priatel JJ, Orban PC, Verchere CB. Prevention of autoimmune diabetes and islet allograft rejection by beta cell expression of XIAP: Insight into possible mechanisms of local immunomodulation. Mol Cell Endocrinol 2018; 477:48-56. [PMID: 29883690 DOI: 10.1016/j.mce.2018.05.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 05/22/2018] [Accepted: 05/29/2018] [Indexed: 12/01/2022]
Abstract
Overexpression of the X-linked inhibitor of apoptosis (XIAP) prevents islet allograft rejection. We constructed an adeno-associated virus expressing XIAP driven by the rat insulin promoter (dsAAV8-RIP-XIAP) for long-term beta-cell gene expression in vivo. Pancreatic delivery of dsAAV8-RIP-XIAP prevented autoimmune diabetes in 70% of non-obese diabetic (NOD) mice, associated with decreased insulitis. Islets from Balb/c mice transduced with dsAAV8-RIP-XIAP were protected following transplantation into streptozotocin (STZ)-diabetic Bl/6 recipients, associated with decreased graft infiltration. Interestingly, dsAAV8-RIP-XIAP transduction induced expression of lactate dehydrogenase (LDHA) and monocarboxylate transporter 1 (MCT1), two genes normally suppressed in beta cells and involved in production and release of lactate, a metabolite known to suppress local immune responses. Transduction of Balb/c islets with AAV8-RIP-LDHA-MCT1 tended to prolong allograft survival following transplant into STZ-diabetic Bl/6 recipients. These findings suggest that XIAP has therapeutic potential in autoimmune diabetes and raise the possibility that local lactate production may play a role in XIAP-mediated immunomodulation.
Collapse
Affiliation(s)
- Mercè Obach
- Departments of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Azadeh Hosseini-Tabatabaei
- Departments of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada; Surgery, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Joel Montane
- Departments of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Katarina Wind
- Departments of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Galina Soukhatcheva
- Surgery, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Derek Dai
- Surgery, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - John J Priatel
- Departments of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Paul C Orban
- Surgery, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - C Bruce Verchere
- Departments of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada; Surgery, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada.
| |
Collapse
|
6
|
Lee M, Kim MJ, Oh J, Piao C, Park YW, Lee DY. Gene delivery to pancreatic islets for effective transplantation in diabetic animal. J IND ENG CHEM 2017. [DOI: 10.1016/j.jiec.2017.07.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
7
|
Ramanadham S, Ali T, Ashley JW, Bone RN, Hancock WD, Lei X. Calcium-independent phospholipases A2 and their roles in biological processes and diseases. J Lipid Res 2015; 56:1643-68. [PMID: 26023050 DOI: 10.1194/jlr.r058701] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Indexed: 12/24/2022] Open
Abstract
Among the family of phospholipases A2 (PLA2s) are the Ca(2+)-independent PLA2s (iPLA2s) and they are designated group VI iPLA2s. In relation to secretory and cytosolic PLA2s, the iPLA2s are more recently described and details of their expression and roles in biological functions are rapidly emerging. The iPLA2s or patatin-like phospholipases (PNPLAs) are intracellular enzymes that do not require Ca(2+) for activity, and contain lipase (GXSXG) and nucleotide-binding (GXGXXG) consensus sequences. Though nine PNPLAs have been recognized, PNPLA8 (membrane-associated iPLA2γ) and PNPLA9 (cytosol-associated iPLA2β) are the most widely studied and understood. The iPLA2s manifest a variety of activities in addition to phospholipase, are ubiquitously expressed, and participate in a multitude of biological processes, including fat catabolism, cell differentiation, maintenance of mitochondrial integrity, phospholipid remodeling, cell proliferation, signal transduction, and cell death. As might be expected, increased or decreased expression of iPLA2s can have profound effects on the metabolic state, CNS function, cardiovascular performance, and cell survival; therefore, dysregulation of iPLA2s can be a critical factor in the development of many diseases. This review is aimed at providing a general framework of the current understanding of the iPLA2s and discussion of the potential mechanisms of action of the iPLA2s and related involved lipid mediators.
Collapse
Affiliation(s)
- Sasanka Ramanadham
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294 Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Tomader Ali
- Undergraduate Research Office, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Jason W Ashley
- Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA 19104
| | - Robert N Bone
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294 Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294
| | - William D Hancock
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294 Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Xiaoyong Lei
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294 Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294
| |
Collapse
|
8
|
Barbour SE, Nguyen PT, Park M, Emani B, Lei X, Kambalapalli M, Shultz JC, Wijesinghe D, Chalfant CE, Ramanadham S. Group VIA Phospholipase A2 (iPLA2β) Modulates Bcl-x 5'-Splice Site Selection and Suppresses Anti-apoptotic Bcl-x(L) in β-Cells. J Biol Chem 2015; 290:11021-31. [PMID: 25762722 DOI: 10.1074/jbc.m115.648956] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Indexed: 01/09/2023] Open
Abstract
Diabetes is a consequence of reduced β-cell function and mass, due to β-cell apoptosis. Endoplasmic reticulum (ER) stress is induced during β-cell apoptosis due to various stimuli, and our work indicates that group VIA phospholipase A2β (iPLA2β) participates in this process. Delineation of underlying mechanism(s) reveals that ER stress reduces the anti-apoptotic Bcl-x(L) protein in INS-1 cells. The Bcl-x pre-mRNA undergoes alternative pre-mRNA splicing to generate Bcl-x(L) or Bcl-x(S) mature mRNA. We show that both thapsigargin-induced and spontaneous ER stress are associated with reductions in the ratio of Bcl-x(L)/Bcl-x(S) mRNA in INS-1 and islet β-cells. However, chemical inactivation or knockdown of iPLA2β augments the Bcl-x(L)/Bcl-x(S) ratio. Furthermore, the ratio is lower in islets from islet-specific RIP-iPLA2β transgenic mice, whereas islets from global iPLA2β(-/-) mice exhibit the opposite phenotype. In view of our earlier reports that iPLA2β induces ceramide accumulation through neutral sphingomyelinase 2 and that ceramides shift the Bcl-x 5'-splice site (5'SS) selection in favor of Bcl-x(S), we investigated the potential link between Bcl-x splicing and the iPLA2β/ceramide axis. Exogenous C6-ceramide did not alter Bcl-x 5'SS selection in INS-1 cells, and neutral sphingomyelinase 2 inactivation only partially prevented the ER stress-induced shift in Bcl-x splicing. In contrast, 5(S)-hydroxytetraenoic acid augmented the ratio of Bcl-x(L)/Bcl-x(S) by 15.5-fold. Taken together, these data indicate that β-cell apoptosis is, in part, attributable to the modulation of 5'SS selection in the Bcl-x pre-mRNA by bioactive lipids modulated by iPLA2β.
Collapse
Affiliation(s)
- Suzanne E Barbour
- From the Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia 23298-0614
| | - Phuong T Nguyen
- From the Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia 23298-0614
| | - Margaret Park
- From the Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia 23298-0614
| | - Bhargavi Emani
- From the Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia 23298-0614
| | - Xiaoyong Lei
- the Department of Cell, Developmental, and Integrative Biology and Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Mamatha Kambalapalli
- From the Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia 23298-0614
| | - Jacqueline C Shultz
- From the Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia 23298-0614
| | - Dayanjan Wijesinghe
- From the Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia 23298-0614, the Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia 23249
| | - Charles E Chalfant
- From the Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia 23298-0614, the Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia 23249, the Massey Cancer Center, Richmond, Virginia 23298, and the Virginia Commonwealth University Reanimation Engineering Science Center, Richmond, Virginia 23298
| | - Sasanka Ramanadham
- the Department of Cell, Developmental, and Integrative Biology and Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, Alabama 35294,
| |
Collapse
|
9
|
Hajmrle C, Ferdaoussi M, Plummer G, Spigelman AF, Lai K, Manning Fox JE, MacDonald PE. SUMOylation protects against IL-1β-induced apoptosis in INS-1 832/13 cells and human islets. Am J Physiol Endocrinol Metab 2014; 307:E664-73. [PMID: 25139051 PMCID: PMC4200309 DOI: 10.1152/ajpendo.00168.2014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Posttranslational modification by the small ubiquitin-like modifier (SUMO) peptides, known as SUMOylation, is reversed by the sentrin/SUMO-specific proteases (SENPs). While increased SUMOylation reduces β-cell exocytosis, insulin secretion, and responsiveness to GLP-1, the impact of SUMOylation on islet cell survival is unknown. Mouse islets, INS-1 832/13 cells, or human islets were transduced with adenoviruses to increase either SENP1 or SUMO1 or were transfected with siRNA duplexes to knockdown SENP1. We examined insulin secretion, intracellular Ca²⁺ responses, induction of endoplasmic reticulum stress markers and inducible nitric oxide synthase (iNOS) expression, and apoptosis by TUNEL and caspase 3 cleavage. Surprisingly, upregulation of SENP1 reduces insulin secretion and impairs intracellular Ca²⁺ handling. This secretory dysfunction is due to SENP1-induced cell death. Indeed, the detrimental effect of SENP1 on secretory function is diminished when two mediators of β-cell death, iNOS and NF-κB, are pharmacologically inhibited. Conversely, enhanced SUMOylation protects against IL-1β-induced cell death. This is associated with reduced iNOS expression, cleavage of caspase 3, and nuclear translocation of NF-κB. Taken together, these findings identify SUMO1 as a novel antiapoptotic protein in islets and demonstrate that reduced viability accounts for impaired islet function following SENP1 up-regulation.
Collapse
Affiliation(s)
- Catherine Hajmrle
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Mourad Ferdaoussi
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Gregory Plummer
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Aliya F Spigelman
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Krista Lai
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Jocelyn E Manning Fox
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Patrick E MacDonald
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
10
|
Ohashi K, Okano T. Functional Tissue Engineering of the Liver and Islets. Anat Rec (Hoboken) 2013; 297:73-82. [DOI: 10.1002/ar.22810] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 09/13/2013] [Indexed: 01/01/2023]
Affiliation(s)
- Kazuo Ohashi
- Institute of Advanced Biomedical Engineering and Science; Tokyo Women's Medical University; Shinjyuku-ku Tokyo Japan
- Department of Gastroenterological Surgery; Tokyo Women's Medical University; Shinjyuku-ku Tokyo Japan
| | - Teruo Okano
- Institute of Advanced Biomedical Engineering and Science; Tokyo Women's Medical University; Shinjyuku-ku Tokyo Japan
| |
Collapse
|
11
|
Wu H, Pagadala J, Yates CR, Miller D, Mahato RI. Synthesis and characterization of an anti-apoptotic immunosuppressive compound for improving the outcome of islet transplantation. Bioconjug Chem 2013; 24:2036-44. [PMID: 24256337 DOI: 10.1021/bc400369t] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Mycophenolic acid (MPA) is a commonly used immunosuppressive drug for human islet transplantation. However, it is toxic to transplanted islets, causing primary nonfunction. We recently synthesized a quinic acid derivative, 1,3,4,5-tetrahydroxy-N-propylcyclohexanecarboxamide (KZ41), which has anti-inflammatory and anti-apoptotic effects. We hypothesized that the conjugate (E)-2,3,5-trihydroxy-5-(propylcarbamoyl) cyclohexyl 6-(4-ethoxy-6-methoxy-7-methyl-3-oxo-1,3-dihydroisobenzofuran-5-yl)-4-methylhex-4-enoate (JP-3-110), which is composed of KZ41 and MPA through esterification, can suppress the immune rejection while inducing less toxicity. Early characterization showed that the solubility of JP-3-110 was significantly higher than that of MPA, though JP-3-110 was still poorly water-soluble. The ester bond connecting KZ41 and MPA is stable for a limited duration (<4 weeks). Pharmacological studies demonstrated that JP-3-110 induced significantly less activated caspase 3 and apoptotic cell death of human islets than MPA, while maintaining an equally potent immunosuppressive effect. A similar immunosuppressive effect of JP-3-110 and MPA in humanized NOD.Cg-Prkdc(scid)Il2rg(tm1Wjl)/SzJ (NOD scid gamma, NSG) mice with adoptively transferred human immunity was observed. Taken together, our results demonstrated that JP-3-110 can be a safer immunosuppressive agent for human islet transplantation.
Collapse
Affiliation(s)
- Hao Wu
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center , Memphis, Tennessee, United States
| | | | | | | | | |
Collapse
|
12
|
Le Bacquer O, Queniat G, Gmyr V, Kerr-Conte J, Lefebvre B, Pattou F. mTORC1 and mTORC2 regulate insulin secretion through Akt in INS-1 cells. J Endocrinol 2013; 216:21-9. [PMID: 23092880 DOI: 10.1530/joe-12-0351] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Regulated associated protein of mTOR (Raptor) and rapamycin-insensitive companion of mTOR (rictor) are two proteins that delineate two different mTOR complexes, mTORC1 and mTORC2 respectively. Recent studies demonstrated the role of rictor in the development and function of β-cells. mTORC1 has long been known to impact β-cell function and development. However, most of the studies evaluating its role used either drug treatment (i.e. rapamycin) or modification of expression of proteins known to modulate its activity, and the direct role of raptor in insulin secretion is unclear. In this study, using siRNA, we investigated the role of raptor and rictor in insulin secretion and production in INS-1 cells and the possible cross talk between their respective complexes, mTORC1 and mTORC2. Reduced expression of raptor is associated with increased glucose-stimulated insulin secretion and intracellular insulin content. Downregulation of rictor expression leads to impaired insulin secretion without affecting insulin content and is able to correct the increased insulin secretion mediated by raptor siRNA. Using dominant-negative or constitutively active forms of Akt, we demonstrate that the effect of both raptor and rictor is mediated through alteration of Akt signaling. Our finding shed new light on the mechanism of control of insulin secretion and production by the mTOR, and they provide evidence for antagonistic effect of raptor and rictor on insulin secretion in response to glucose by modulating the activity of Akt, whereas only raptor is able to control insulin biosynthesis.
Collapse
Affiliation(s)
- Olivier Le Bacquer
- UMR859, Faculty of Medicine, Université Lille Nord de France, 1 Place de Verdun, F-59000 Lille, France.
| | | | | | | | | | | |
Collapse
|
13
|
Gallo R, Natale M, Vendrame F, Boggi U, Filipponi F, Marchetti P, Laghi Pasini F, Dotta F. In vitro effects of mycophenolic acid on survival, function, and gene expression of pancreatic beta-cells. Acta Diabetol 2012; 49 Suppl 1:S123-31. [PMID: 22249339 DOI: 10.1007/s00592-011-0368-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Accepted: 12/23/2011] [Indexed: 12/24/2022]
Abstract
Post-transplant diabetes mellitus represents an important complication of prolonged immunosuppressive treatment after solid organ transplantation. The immunosuppressive toxicity, responsible for a persistent impairment of glucose metabolism in pancreatic islet-transplanted patients, is mainly attributed to calcineurin inhibitors and steroids, while other immunosuppressive molecules (azathioprine and mycophenolic acid, MPA) are considered not to have a toxic effect. In the present study, in vitro effects of MPA have been investigated in mouse beta-cell lines (βTC-1 and βTC-6) and in purified human pancreatic islets. βTC-1, βTC-6, and human pancreatic islets were exposed to various concentrations of MPA for different times. Consequently, we evaluated the viability, the induction of apoptosis, the glucose-stimulated insulin secretion, and the expression of β-cell function genes (Isl1, Pax6, Glut-2, glucokinase) and apoptosis-related genes (Bax and Bcl2). βTC-1, βTC-6, and human islets treated, respectively, for 48 and 72 h with 15-30 nM MPA showed altered islet architecture, as compared with control cells. We observed for βTC-1 and βTC-6 almost 70% reduction in cell viability; three to sixfold induction of TUNEL/apoptotic-positive cells quantified by FACS analysis. A twofold increase in apoptotic cells was observed in human islets after MPA exposure associated with strong inhibition of glucose-stimulated insulin secretion. Furthermore, we showed significant down-regulation of gene expression of molecules involved in β-cell function and increase rate between Bax/Bcl2. Our data demonstrate that MPA has an in vitro diabetogenic effect interfering at multiple levels with survival and function of murine and human pancreatic β-cells.
Collapse
Affiliation(s)
- R Gallo
- Department of Internal Medicine, Diabetes Unit, Endocrine and Metabolic Sciences and Biochemistry, University of Siena, Viale Bracci 18, 53100 Siena, Italy
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Zhao F, Huang F, Tang M, Li X, Zhang N, Amfilochiadis A, Li Y, Hu R, Jin T, Peng C, Wang Q. Nodal induces apoptosis through activation of the ALK7 signaling pathway in pancreatic INS-1 β-cells. Am J Physiol Endocrinol Metab 2012; 303:E132-43. [PMID: 22550067 PMCID: PMC3404563 DOI: 10.1152/ajpendo.00074.2012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We demonstrated previously that the activation of ALK7 (activin receptor-like kinase-7), a member of the type I receptor serine/threonine kinases of the TGF-β superfamily, resulted in increased apoptosis and reduced proliferation through suppression of Akt signaling and the activation of Smad2-dependent signaling pathway in pancreatic β-cells. Here, we show that Nodal activates ALK7 signaling and regulates β-cell apoptosis. We detected Nodal expression in the clonal β-cell lines and rodent islet β-cells. Induction of β-cell apoptosis by treatment with high glucose, palmitate, or cytokines significantly increased Nodal expression in clonal INS-1 β-cells and isolated rat islets. The stimuli induced upregulation of Nodal expression levels were associated with elevation of ALK7 protein and enhanced phosphorylated Smad3 protein. Nodal treatment or overexpression of Nodal dose- or time-dependently increased active caspase-3 levels in INS-1 cells. Nodal-induced apoptosis was associated with decreased Akt phosphorylation and reduced expression level of X-linked inhibitor of apoptosis (XIAP). Remarkably, overexpression of XIAP or constitutively active Akt, or ablation of Smad2/3 activity partially blocked Nodal-induced apoptosis. Furthermore, siRNA-mediated ALK7 knockdown significantly attenuated Nodal-induced apoptosis of INS-1 cells. We suggest that Nodal-induced apoptosis in β-cells is mediated through ALK7 signaling involving the activation of Smad2/3-caspase-3 and the suppression of Akt and XIAP pathways and that Nodal may exert its biological effects on the modulation of β-cell survival and β-cell mass in an autocrine fashion.
Collapse
Affiliation(s)
- Fang Zhao
- Division of Endocrinology and Metabolism, the Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Induction of protective genes leads to islet survival and function. J Transplant 2011; 2011:141898. [PMID: 22220267 PMCID: PMC3246756 DOI: 10.1155/2011/141898] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 09/01/2011] [Indexed: 12/16/2022] Open
Abstract
Islet transplantation is the most valid approach to the treatment of type 1 diabetes. However, the function of transplanted islets is often compromised since a large number of β cells undergo apoptosis induced by stress and the immune rejection response elicited by the recipient after transplantation. Conventional treatment for islet transplantation is to administer immunosuppressive drugs to the recipient to suppress the immune rejection response mounted against transplanted islets. Induction of protective genes in the recipient (e.g., heme oxygenase-1 (HO-1), A20/tumor necrosis factor alpha inducible protein3 (tnfaip3), biliverdin reductase (BVR), Bcl2, and others) or administration of one or more of the products of HO-1 to the donor, the islets themselves, and/or the recipient offers an alternative or synergistic approach to improve islet graft survival and function. In this perspective, we summarize studies describing the protective effects of these genes on islet survival and function in rodent allogeneic and xenogeneic transplantation models and the prevention of onset of diabetes, with emphasis on HO-1, A20, and BVR. Such approaches are also appealing to islet autotransplantation in patients with chronic pancreatitis after total pancreatectomy, a procedure that currently only leads to 1/3 of transplanted patients being diabetes-free.
Collapse
|
16
|
Improving islet engraftment by gene therapy. J Transplant 2011; 2011:594851. [PMID: 22132301 PMCID: PMC3202131 DOI: 10.1155/2011/594851] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 08/22/2011] [Indexed: 11/18/2022] Open
Abstract
Islet cell transplantation is currently the only feasible long-term treatment option for patients with type 1 diabetes. However, the majority of transplanted islets experience damage and apoptosis during the isolation process, a blood-mediated inflammatory microenvironment in the portal vein upon islet infusion, hypoxia induced by the low oxygenated milieu, and poor-revascularization-mediated lack of nutrients, and impaired hormone modulation in the local transplanted site. Strategies using genetic modification methods through overexpression or silencing of those proteins involved in promoting new formation of blood vessels or inhibition of apoptosis may overcome these hurdles and improve islet engraftment outcomes.
Collapse
|
17
|
Campbell PD, Weinberg A, Chee J, Mariana L, Ayala R, Hawthorne WJ, O'Connell PJ, Loudovaris T, Cowley MJ, Kay TW, Grey ST, Thomas HE. Expression of pro- and antiapoptotic molecules of the Bcl-2 family in human islets postisolation. Cell Transplant 2011; 21:49-60. [PMID: 21535910 DOI: 10.3727/096368911x566262] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Human islets are subjected to a number of stresses before and during their isolation that may influence their survival and engraftment after transplantation. Apoptosis is likely to be activated in response to these stresses. Apoptosis due to intrinsic stresses is regulated by pro- and antiapoptotic members of the Bcl-2 family. While the role of the Bcl-2 family in apoptosis of rodent islets is becoming increasingly understood, little is known about which of these molecules are expressed or required for apoptosis of human islets. This study investigated the expression of the Bcl-2 family of molecules in isolated human islets. RNA and protein lysates were extracted from human islets immediately postisolation. At the same time, standard quality control assays including viability staining and β-cell content were performed on each islet preparation. Microarrays, RT-PCR, and Western blotting were performed on islet RNA and protein. The prosurvival molecules Bcl-xl and Mcl-1, but not Bcl-2, were highly expressed. The multidomain proapoptotic effector molecule Bax was expressed at higher levels than Bak. Proapoptotic BH3-only molecules were expressed at low levels, with Bid being the most abundant. The proapoptotic molecules BNIP3, BNIP3L, and Beclin-1 were all highly expressed, indicating exposure of islets to oxygen and nutrient deprivation during isolation. Our data provide a comprehensive analysis of expression levels of pro- and antiapoptotic Bcl-2 family members in isolated human islets. Knowledge of which molecules are expressed will guide future research to understand the apoptotic pathways activated during isolation or after transplantation. This is crucial for the design of methods to achieve improved transplantation outcomes.
Collapse
|
18
|
Li F, Mahato RI. RNA interference for improving the outcome of islet transplantation. Adv Drug Deliv Rev 2011; 63:47-68. [PMID: 21156190 DOI: 10.1016/j.addr.2010.11.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 11/19/2010] [Accepted: 11/25/2010] [Indexed: 01/06/2023]
Abstract
Islet transplantation has the potential to cure type 1 diabetes. Despite recent therapeutic success, it is still not common because a large number of transplanted islets get damaged by multiple challenges including instant blood mediated inflammatory reaction, hypoxia/reperfusion injury, inflammatory cytokines, and immune rejection. RNA interference (RNAi) is a novel strategy to selectively degrade target mRNA. The use of RNAi technologies to downregulate the expression of harmful genes has the potential to improve the outcome of islet transplantation. The aim of this review is to gain a thorough understanding of biological obstacles to islet transplantation and discuss how to overcome these barriers using different RNAi technologies. This eventually will help improve islet survival and function post transplantation. Chemically synthesized small interferring RNA (siRNA), vector based short hairpin RNA (shRNA), and their critical design elements (such as sequences, promoters, and backbone) are discussed. The application of combinatorial RNAi in islet transplantation is also discussed. Last but not the least, several delivery strategies for enhanced gene silencing are discussed, including chemical modification of siRNA, complex formation, bioconjugation, and viral vectors.
Collapse
Affiliation(s)
- Feng Li
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN 38103, USA
| | | |
Collapse
|
19
|
Wu H, Panakanti R, Li F, Mahato RI. XIAP gene expression protects β-cells and human islets from apoptotic cell death. Mol Pharm 2010; 7:1655-66. [PMID: 20677802 DOI: 10.1021/mp100070j] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Islet transplantation has the potential to treat type I diabetes, however, its clinical application is limited due to the massive apoptotic cell death and other post-transplantation challenges to islet grafts. Therefore, the objective of this study was to determine whether ex vivo transduction of rat insulin producing INS-1E cells and human islets with adenoviral vector encoding human X-linked inhibitor of apoptosis (Adv-hXIAP) can protect them from inflammatory cytokines and improve their viability and function. There was dose dependent XIAP gene expression. XIAP expression led to decrease in the activities of caspase 3/7, 8 and 9, resulting in reduced apoptotic cell death induced by a cocktail of inflammatory cytokines such as IL-1β, TNFα, and IFNγ. Prolonged normoglycemic control could be achieved by transplantation of Adv-XIAP transduced human islets under the kidney capsule of streptozotocin induced diabetic NOD-SCID mice. Immunohistological staining of the islets bearing kidney sections at day 42 after transplantation was positive for insulin. Moreover, the protective effect of XIAP was reversed by coadministration of XIAP inhibitor embelin. These results indicate that ex vivo transduction of islets with Adv-XIAP will decrease cytokine induced apoptosis and improve the outcome of islet transplantation.
Collapse
Affiliation(s)
- Hao Wu
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN 38103-3308, USA
| | | | | | | |
Collapse
|
20
|
Balibrea del Castillo JM, Arias-Díaz J, García Martín MC, Vives-Pi M, García Pérez JC, Cantero Cid R, Vara Ameigeiras E, Balibrea Cantero JL. [Cytoprotective effect of low-dose tacrolimus on islets of Langerhans in cultures subjected to stimulation by acute rejection cytokines]. Cir Esp 2010; 87:372-7. [PMID: 20452578 DOI: 10.1016/j.ciresp.2010.03.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Revised: 01/09/2010] [Accepted: 03/12/2010] [Indexed: 11/29/2022]
Abstract
INTRODUCTION The improvement in pancreatic islet transplantation results is due to immunosuppression protocols that include, among others, low-dose tacrolimus. Both anti-inflammatory and anti-oxidant effects of tacrolimus could be useful in preventing primary rejection. AIM To evaluate in vitro islet low-dose tacrolimus response after pro-inflammatory stimulation. MATERIAL AND METHODS Isolated rat islets were cultured in RPMI medium in the presence of IL-1 (50 UI/mL) plus IF-gamma (1000 UI/mL) and tacrolimus (5 ng/mL). The 24 h production of lipoperoxide (LPO) and nitric oxide (NO) were measured as oxidative stress markers. Determination of apoptosis markers (nucleosome content and Bcl-2) was also performed. RESULTS Oxidative stress (LPO 10.1+/-1.16 pmol/islet x 24; NO 19.1+/-3.28 pmol/isletx24 h) and apoptosis (nucleosome 0.24+/-0.04 UI/islet; Bcl-2 0.69+/-0.212 UI/islet) markers showed a very significant increase after cytokine stimulation (p<0.01). Both effects improved by adding tacrolimus to the medium. Protective effect was complete when lipoperoxide (1.58 pmol/isletx24 h), nitric oxide (9.81 pmol/isletx24 h) and Bcl-2 (1.37+/-0.23 UI/islet) were determined. CONCLUSION In vitro cytoprotective effect of low-dose tacrolimus on isolated rat islets decreases both oxidative stress and apoptosis markers after stimulation of pro-inflammatory mediators.
Collapse
Affiliation(s)
- José María Balibrea del Castillo
- Servicio de Cirugía General y Digestiva, Hospital Universitario Germans Trias i Pujol, Departamento de Cirugía, Universidad Autónoma de Barcelona, Barcelona, Spain.
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Rickels MR, Mueller R, Teff KL, Naji A. {beta}-Cell secretory capacity and demand in recipients of islet, pancreas, and kidney transplants. J Clin Endocrinol Metab 2010; 95:1238-46. [PMID: 20097708 PMCID: PMC2841536 DOI: 10.1210/jc.2009-2289] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
CONTEXT beta-Cell secretory capacity, a measure of functional beta-cell mass, is often impaired in islet transplant recipients, likely because of a low engrafted beta-cell mass, although calcineurin inhibitor toxicity is often cited as the explanation. OBJECTIVE We sought to determine whether use of the calcineurin inhibitor tacrolimus was associated with reduced beta-cell secretory capacity or with increased beta-cell secretory demand independent of engrafted islet mass. DESIGN AND PARTICIPANTS We compared metabolic measures in five intraportal islet recipients vs. 10 normal controls and in seven portally-drained pancreas-kidney and eight nondiabetic kidney recipients vs. nine kidney donor controls. All transplant groups received comparable exposure to tacrolimus, and each transplant group was matched for kidney function to its respective control group. INTERVENTION AND MAIN OUTCOME MEASURES All participants underwent glucose-potentiated arginine testing where acute insulin responses to arginine (5 g) were determined under fasting (AIR(arg)), 230 mg/dl (AIR(pot)), and 340 mg/dl (AIR(max)) clamp conditions, and AIR(max) gives the beta-cell secretory capacity. Insulin sensitivity (M/I) and proinsulin secretory ratios (PISRs) were assessed to determine whether tacrolimus increased beta-cell secretory demand. RESULTS Insulin responses were significantly lower than normal in the islet group for AIR(arg) (P < 0.05), AIR(pot) (P < 0.01), and AIR(max) (P < 0.01), whereas responses in the pancreas-kidney and kidney transplant groups were not different than in the kidney donor group. M/I and PISRs were not different in any of the transplant vs. control groups. CONCLUSIONS Impaired beta-cell secretory capacity in islet transplantation is best explained by a low engrafted beta-cell mass and not by a deleterious effect of tacrolimus.
Collapse
Affiliation(s)
- Michael R Rickels
- University of Pennsylvania School of Medicine, 700 Clinical Research Building, 415 Curie Boulevard, Philadelphia, Pennsylvania 19104-6149, USA.
| | | | | | | |
Collapse
|
22
|
Human Islet Autotransplantation: The Trail Thus Far and the Highway Ahead. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 654:711-24. [DOI: 10.1007/978-90-481-3271-3_31] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
23
|
Abstract
Apoptosis of beta cells is a feature of both type 1 and type 2 diabetes as well as loss of islets after transplantation. In type 1 diabetes, beta cells are destroyed by immunological mechanisms. In type 2 diabetes abnormal levels of metabolic factors contribute to beta cell failure and subsequent apoptosis. Loss of beta cells after islet transplantation is due to many factors including the stress associated with islet isolation, primary graft non-function and allogeneic graft rejection. Irrespective of the exact mediators, highly conserved intracellular pathways of apoptosis are triggered. This review will outline the molecular mediators of beta cell apoptosis and the intracellular pathways activated.
Collapse
Affiliation(s)
- Helen E Thomas
- St. Vincent's Institute of Medical Research, 41 Victoria Parade, Fitzroy, VIC 3065, Australia.
| | | | | | | | | |
Collapse
|
24
|
|
25
|
Del Castillo JMB, García-Martín MC, Arias-Díaz J, Giné E, Vara E, Cantero JLB. Antiapoptotic effect of tacrolimus on cytokine-challenged human islets. Cell Transplant 2009; 18:1237-46. [PMID: 19660176 DOI: 10.3727/096368909x12483162197240] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Our goal was to investigate whether previously related antiapoptotic and anti-inflammatory effects of tacrolimus could be useful in protecting human islets cultured in the presence of several proinflammatory mediators. Human islets obtained from cadaveric donors after intraductal infusion with collagenase, mechanical digestion, and continuous Ficoll gradient purification were cultured in RPMI-1640 medium for 24 h. Escherichia coli lipopolysaccharide (10 microg/ml) or interleukin-1 (50 UI/ml) + gamma-IF (1000 UI/ml) and low-dose tacroliumus (5 ng/ml) were added. Homogenized samples (300 IE) from five different donors where assigned to four different experimental groups (control, treatment, cytokines, and cytokines + treatment). To evaluate islet damage and apoptotic response, nucleosome content, Bcl-2 protein levels, caspase-3, -8, and -9 levels, and insulin concentration were measured. Also, TNF-alpha and IL-6 levels where assessed as indicators of the inflammatory response. All proapoptotic markers, TNF-alpha, and IL-6 levels were augmented after both LPS and cytokine stimulation. Tacrolimus reduced significantly all of them and restored baseline values of nucleosome and caspase-9 in both experiments and Bcl-2 and caspase-3 when IL-1 + gamma-IF was added. Twenty-four-hour insulin concentration diminished when LPS or IL-1 + gamma-IF were present. Tacrolimus treatment restored insulin levels in both experiments. These results suggest that in vitro apoptotic events and media insulin concentration decrease after proinflammatory stimulation can be reverted using low-dose tacrolimus.
Collapse
|
26
|
Rauch MC, San Martín A, Ojeda D, Quezada C, Salas M, Cárcamo JG, Yañez AJ, Slebe JC, Claude A. Tacrolimus causes a blockage of protein secretion which reinforces its immunosuppressive activity and also explains some of its toxic side-effects. Transpl Immunol 2009; 22:72-81. [PMID: 19628039 DOI: 10.1016/j.trim.2009.07.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Revised: 07/06/2009] [Accepted: 07/13/2009] [Indexed: 11/29/2022]
Abstract
BACKGROUND Tacrolimus (FK506) is a macrolide immunosuppressant drug from the calcineurin inhibitor family, widely used in solid organ and islet cell transplantation, but produces significant side-effects. OBJECTIVE This study examined the effect of FK506 on interleukin-2 (IL-2) and insulin secretion, establishing a novel characteristic of this drug that could explain its diverse adverse effects, and developed an experimental model for the simultaneous analysis of mRNA expression and protein secretion affected by this drug. METHODS The IL-2 levels when tacrolimus was administered were analysed by Western blot, immunocytochemistry and RT-PCR in a T lymphocyte cellular line (Jurkat) 24 h post-stimulation. The insulin levels when tacrolimus was administered were analysed 4 h after stimulation of glucose-induced insulin secretion in a pancreatic cellular line (MIN6). RESULTS The previously published information describes tacrolimus as only capable of partially blocking IL-2 mRNA expression. In our hands, the cellular content of IL-2 is almost undetectable in stimulated Jurkat cells and can be detected in cellular extracts only when the secretory pathway is blocked by brefeldin A (BFA). BFA added 2 h after the beginning of stimulation was able to inhibit IL-2 secretion, without affecting IL-2 mRNA expression. Therefore BFA utilization allowed us to establish a model to analyze the effect on IL-2 secretion, separately from its expression. Tacrolimus added before stimulation inhibits only IL-2 synthesis, but blocks IL-2 protein secretion when added 2 h after stimulation. Similarly, tacrolimus is also capable of blocking the glucose-stimulated secretion of insulin by MIN6 cells. An increase of the intracellular content can be detected concomitantly with a decrease of the hormone measured in the culture medium. CONCLUSIONS Results of this study indicate that tacrolimus possesses another important effect in addition to the inhibition of IL-2 gene transcription, namely the ability to act as a general inhibitor of the protein secretory pathway. These results strongly suggest that the diabetogenic effect of the immune suppressant FK506 could be caused by the blockade of insulin secretion. This novel effect also provides an explanation for other side-effects observed in immunosuppressive treatment.
Collapse
Affiliation(s)
- M C Rauch
- Instituto de Bioquímica, Universidad Austral de Chile, Chile
| | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Use of a systems biology approach to understand pancreatic beta-cell death in Type 1 diabetes. Biochem Soc Trans 2008; 36:321-7. [PMID: 18481950 DOI: 10.1042/bst0360321] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Accumulating evidence indicates that beta-cells die by apoptosis in T1DM (Type 1 diabetes mellitus). Apoptosis is an active gene-directed process, and recent observations suggest that beta-cell apoptosis depends on the parallel and/or sequential up- and down-regulation of hundreds of genes controlled by key transcription factors such as NF-kappaB (nuclear factor kappaB) and STAT-1 (signal transducer and activator of transcription 1). Understanding the regulation of these gene networks, and how they modulate beta-cell death and the 'dialogue' between beta-cells and the immune system, will require a systems biology approach to the problem. This will hopefully allow the search for a cure for T1DM to move from a 'trial-and-error' approach to one that is really mechanistically driven.
Collapse
|
28
|
Abstract
BACKGROUND Sirolimus plays a critical role in facilitating steroid-free immunosuppression, in conjunction with low dose tacrolimus, in current islet transplantation. Although several studies have investigated the effects of sirolimus on islet cells, conflicting results have been reported. In this study, we assessed the effects of sirolimus supplementation in culture media on human islet preparations, focusing on the anti-proinflammatory aspects. METHODS Human islet preparations were divided into four groups: pure (purity >90%) sirolimus (30 ng/mL); pure control (0 ng/mL); impure (purity 40%-60%) sirolimus; and impure control. All groups were cultured for 3 days and assessed regarding glucose stimulated insulin release, fractional beta-cell viability, beta-cell, and macrophage content. Cytokine and chemokine production from islet preparations and sorted pancreatic ductal cells were also examined. RESULTS Stimulated insulin release in the impure sirolimus group was significantly increased (P=0.024), as previously reported. Although fractional beta-cell viability showed no significant differences, beta-cell survival during culture significantly increased in impure sirolimus group when compared with the impure control group (P=0.015). Tumor necrosis factor-alpha, interleukin-1beta, monocyte chemotactic protein-1, and macrophage inflammatory protein-1beta production from the impure sirolimus group significantly decreased (P<0.05). Furthermore, tumor necrosis factor-alpha and macrophage inflammatory protein-1beta production from sorted ductal cells significantly decreased in the sirolimus group (P<0.05). The number of macrophages contained in islet preparations significantly decreased in the impure sirolimus group when compared with the impure control group (P<0.05). CONCLUSIONS Sirolimus improved not only stimulated insulin release, but also beta-cell survival during culture. The antiinflammatory effects of sirolimus also appear beneficial to islet cells in culture and may be a useful strategy in improving islet transplantation outcomes.
Collapse
|
29
|
Shi YH, Ding WX, Zhou J, He JY, Xu Y, Gambotto A, Rabinowich H, Fan J, Yin XM. Expression of X-linked inhibitor-of-apoptosis protein in hepatocellular carcinoma promotes metastasis and tumor recurrence. Hepatology 2008; 48:497-507. [PMID: 18666224 PMCID: PMC2768766 DOI: 10.1002/hep.22393] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
UNLABELLED Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. Despite significantly improved diagnosis and treatment in recent years, the long-term therapeutic effect is compromised by the frequent recurrence and metastasis, of which the molecular mechanisms are not fully understood. Our initial studies in established HCC cell lines with different metastatic capabilities indicated a correlation of metastasis with the resistance to apoptosis and therefore the ability to survive in stressed conditions. Subsequent investigation revealed that increased expression of X-linked inhibitor-of-apoptosis protein (XIAP) was correlated with the resistance to apoptosis and enhanced invasiveness in vitro, which could contribute to increased metastatic foci in vivo. Furthermore, we found that nearly 90% of clinical samples from advanced HCC patients expressed high levels of XIAP. Patients with XIAP-positive tumors had a significantly increased risk of relapse, which resulted from metastasis after total liver resection and orthotopic liver transplantation. Indeed, XIAP expression could be an independent prognostic factor for predicting disease-free survival rate and overall survival rate of these patients. XIAP expression was also highly correlated with advanced cases that exceeded the Milan criteria and could be a prognostic factor for disease-free survival in these patients as well. CONCLUSION Our studies have shown an important molecule in controlling HCC metastasis, defined a biomarker that can be used to predict HCC recurrence and patient survival after treatment, and suggest that XIAP can be a molecular target subject to intervention to reduce metastasis and recurrence.
Collapse
Affiliation(s)
- Ying-Hong Shi
- Department of Liver Surgery, Liver Cancer Research Institute, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Wen-Xing Ding
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh PA 15261, USA
| | - Jian Zhou
- Department of Liver Surgery, Liver Cancer Research Institute, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Jun-Yi He
- Department of Liver Surgery, Liver Cancer Research Institute, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Yang Xu
- Department of Liver Surgery, Liver Cancer Research Institute, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Andrew Gambotto
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh PA 15261, USA
| | - Hannah Rabinowich
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh PA 15261, USA
| | - Jia Fan
- Department of Liver Surgery, Liver Cancer Research Institute, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Xiao-Ming Yin
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh PA 15261, USA
| |
Collapse
|
30
|
Glucose controls CREB activity in islet cells via regulated phosphorylation of TORC2. Proc Natl Acad Sci U S A 2008; 105:10161-6. [PMID: 18626018 DOI: 10.1073/pnas.0800796105] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
CREB is a cAMP- and calcium-responsive transcriptional activator that is required for islet beta cell proliferation and survival. Glucose and incretin hormones elicit beta cell insulin secretion and promote synergistic CREB activity by inducing the nuclear relocalization of TORC2 (also known as Crtc2), a coactivator for CREB. In islet cells under basal conditions when CREB activity is low, TORC2 is phosphorylated and sequestered in the cytoplasm by 14-3-3 proteins. In response to feeding stimuli, TORC2 is dephosphorylated, enters the nucleus, and binds to CREB located at target gene promoters. The dephosphorylation of TORC2 at Ser-171 in response to cAMP is insufficient to account for the dynamics of TORC2 localization and CREB activity in islet cells. Here, we identify Ser-275 of TORC2 as a 14-3-3 binding site that is phosphorylated under low glucose conditions and which becomes dephosphorylated by calcineurin in response to glucose influx. Dephosphorylation of Ser-275 is essential for both glucose and cAMP-mediated activation of CREB in beta cells and islets. Using a cell-based screen of 180 human protein kinases, we identified MARK2, a member of the AMPK family of Ser/Thr kinases, as a Ser-275 kinase that blocks TORC2:CREB activity. Taken together, these data provide the mechanistic underpinning for how cAMP and glucose cooperatively promote a transcriptional program critical for islet cell survival, and identifies MARK2 as a potential target for diabetes treatment.
Collapse
|
31
|
Emamaullee JA, Davis J, Pawlick R, Toso C, Merani S, Cai SX, Tseng B, Shapiro AMJ. The caspase selective inhibitor EP1013 augments human islet graft function and longevity in marginal mass islet transplantation in mice. Diabetes 2008; 57:1556-66. [PMID: 18356409 DOI: 10.2337/db07-1452] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Clinical islet transplantation can provide insulin independence in patients with type 1 diabetes, but chronic graft failure has been observed. This has been attributed in part to loss of >or=60% of the transplanted islets in the peritransplant period, resulting in a marginal implant mass. Strategies designed to maximize survival of the initial islet mass are likely to have major impact in enhancing long-term clinical outcomes. EP1013 (N-benzyloxycabonyl-Val Asp-fluoromethyl ketone [zVD-FMK]), is a broad-spectrum caspase selective inhibitor with no observed toxicity in rodents. RESEARCH DESIGN AND METHODS The therapeutic benefit of EP1013 was examined in a syngeneic rodent islet transplant model using deceased donor human islets to determine whether the amount of tissue required to restore euglycemia in diabetic animals could be reduced. RESULTS EP1013 (combined pretransplant islet culture for 2 h and in vivo treatment for days 0-5 posttransplant) significantly improved marginal islet mass function following syngeneic islet transplantation in mice, even at lower doses, compared with previous studies using the pan-caspase inhibitor N-benzyloxycabonyl-Val Ala-Asp-fluoromethyl ketone (zVAD-FMK). EP1013 supplementation in vitro improved human islet yields following prolonged culture and reversed diabetes following implantation of a marginal human islet mass (80-90% reduction) into mice. CONCLUSIONS Our data suggest that EP1013 therapy will markedly reduce the islet mass required in clinical islet transplantation, improving insulin independence rates following single-donor infusion.
Collapse
|
32
|
McKenzie MD, Carrington EM, Kaufmann T, Strasser A, Huang DCS, Kay TWH, Allison J, Thomas HE. Proapoptotic BH3-only protein Bid is essential for death receptor-induced apoptosis of pancreatic beta-cells. Diabetes 2008; 57:1284-92. [PMID: 18252892 DOI: 10.2337/db07-1692] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Apoptosis of pancreatic beta-cells is critical in both diabetes development and failure of islet transplantation. The role in these processes of pro- and antiapoptotic Bcl-2 family proteins, which regulate apoptosis by controlling mitochondrial integrity, remains poorly understood. We investigated the role of the BH3-only protein Bid and the multi-BH domain proapoptotic Bax and Bak, as well as prosurvival Bcl-2, in beta-cell apoptosis. RESEARCH DESIGN AND METHODS We isolated islets from mice lacking Bid, Bax, or Bak and those overexpressing Bcl-2 and exposed them to Fas ligand, tumor necrosis factor (TNF)-alpha, and proinflammatory cytokines or cytotoxic stimuli that activate the mitochondrial apoptotic pathway (staurosporine, etoposide, gamma-radiation, tunicamycin, and thapsigargin). Nuclear fragmentation was measured by flow cytometry. RESULTS Development and function of islets were not affected by loss of Bid, and Bid-deficient islets were as susceptible as wild-type islets to cytotoxic stimuli that cause apoptosis via the mitochondrial pathway. In contrast, Bid-deficient islets and those overexpressing antiapoptotic Bcl-2 were protected from Fas ligand-induced apoptosis. Bid-deficient islets were also resistant to apoptosis induced by TNF-alpha plus cycloheximide and were partially resistant to proinflammatory cytokine-induced death. Loss of the multi-BH domain proapoptotic Bax or Bak protected islets partially from death receptor-induced apoptosis. CONCLUSIONS These results demonstrate that Bid is essential for death receptor-induced apoptosis of islets, similar to its demonstrated role in hepatocytes. This indicates that blocking Bid activity may be useful for protection of islets from immune-mediated attack and possibly also in other pathological states in which beta-cells are destroyed.
Collapse
Affiliation(s)
- Mark D McKenzie
- St. Vincent's Institute of Medical Research, 41 Victoria Parade, Fitzroy, Victoria, 3065, Australia
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Lai Y, Drobinskaya I, Kolossov E, Chen C, Linn T. Genetic modification of cells for transplantation. Adv Drug Deliv Rev 2008; 60:146-59. [PMID: 18037530 DOI: 10.1016/j.addr.2007.08.039] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Accepted: 08/02/2007] [Indexed: 01/16/2023]
Abstract
Progress in gene therapy has produced promising results that translate experimental research into clinical treatment. Gene modification has been extensively employed in cell transplantation. The main barrier is an effective gene delivery system. Several viral vectors were utilized in end-stage differentiated cells. Recently, successful applications were described with adenovirus-associated vectors. As an alternative, embryonic stem cell- and stem cell-like systems were established for generation of tissue-specified gene-modified cells. Owing to the feasibility for genetic manipulations and the self-renewing potency of these cells they can be used in a way enabling large-scale in vitro production. This approach offers the establishment of in vitro cell culture systems that will deliver sufficient amounts of highly purified, immunoautologous cells suitable for application in regenerative medicine. In this review, the current technology of gene delivery systems to cells is recapitulated and the latest developments for cell transplantation are discussed.
Collapse
|
34
|
Plaumann S, Blume R, Börchers S, Steinfelder HJ, Knepel W, Oetjen E. Activation of the dual-leucine-zipper-bearing kinase and induction of beta-cell apoptosis by the immunosuppressive drug cyclosporin A. Mol Pharmacol 2007; 73:652-9. [PMID: 18042735 DOI: 10.1124/mol.107.040782] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Post-transplant diabetes is an untoward effect often observed under immunosuppressive therapy with cyclosporin A. Besides the development of peripheral insulin resistance and a decrease in insulin gene transcription, a beta-cell toxic effect has been described. However, its molecular mechanism remains unknown. In the present study, the effect of cyclosporin A and the dual leucine-zipper-bearing kinase (DLK) on beta-cell survival was investigated. Cyclosporin A decreased the viability of the insulin-producing pancreatic islet cell line HIT in a time- and concentration-dependent manner. Upon exposure to the immunosuppressant fragmentation of DNA, the activation of the effector caspase-3 and a decrease of full-length caspase-3 and Bcl(XL) were observed in HIT cells and in primary mature murine islets, respectively. Cyclosporin A and tacrolimus, both potent inhibitors of the calcium/calmodulin-dependent phosphatase calcineurin, stimulated the enzymatic activity of cellular DLK in an in vitro kinase assay. Immunocytochemistry revealed that the overexpression of DLK but not its kinase-dead mutant induced apoptosis and enhanced cyclosporin A-induced apoptosis to a higher extent than the drug alone. Moreover, in the presence of DLK, the effective concentration for cyclosporin A-caused apoptosis was similar to its known IC(50) value for the inhibition of calcineurin activity in beta cells. These data suggest that cyclosporin A through inhibition of calcineurin activates DLK, thereby leading to beta-cell apoptosis. This action may thus be a novel mechanism through which cyclosporin A precipitates post-transplant diabetes.
Collapse
Affiliation(s)
- Silke Plaumann
- Molecular Pharmacology, University of Göttingen, Robert-Koch-Str. 40, 37099 Göttingen, Germany
| | | | | | | | | | | |
Collapse
|
35
|
Cross SE, Richards SK, Clark A, Benest AV, Bates DO, Mathieson PW, Johnson PRV, Harper SJ, Smith RM. Vascular endothelial growth factor as a survival factor for human islets: effect of immunosuppressive drugs. Diabetologia 2007; 50:1423-32. [PMID: 17476476 DOI: 10.1007/s00125-007-0670-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Accepted: 03/07/2007] [Indexed: 12/20/2022]
Abstract
AIMS/HYPOTHESIS Rapamycin, part of the immunosuppressive regimen of the Edmonton protocol, has been shown to inhibit vascular endothelial growth factor (VEGF) production and VEGF-mediated survival signalling in tumour cell lines. This study investigates the survival-promoting activities of VEGF in human islets and the effects of rapamycin on islet viability. MATERIALS AND METHODS Levels of VEGF and its receptors in isolated human islets and whole pancreas was determined by western blotting and immunostaining. Islet viability following VEGF or immunosuppressive drug treatment was determined using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Islet VEGF release was measured by ELISA. Mouse islets infected with an adenovirus expressing the gene for VEGF were transplanted syngeneically into streptozotocin-induced diabetic mice, with blood glucose levels measured three times per week. RESULTS Isolated human islets produced multiple isoforms of VEGF and VEGF receptors 1, 2 and 3 and the coreceptor neuropilin 1. Exogenous VEGF (10 ng/ml) prevented human islet death induced by serum starvation, which suggests that VEGF can act as a survival factor for human islets. Transplantation of mouse islets infected with a VEGF-expressing adenovirus in a syngeneic model, improved glycaemic control at day 1 post-transplantation (p < 0.05). Rapamycin at 10 and 100 ng/ml significantly reduced islet VEGF release (by 37 +/- 4% and 43 +/- 6%, respectively; p < 0.05) and at 100 ng/ml reduced islet viability (by 36 +/- 9%) and insulin release (by 47 +/- 7%, all vs vehicle-treated controls; p < 0.05). Tacrolimus had no effect on islet VEGF release or viability. CONCLUSIONS/INTERPRETATION Our data suggest that rapamycin may have deleterious effects on islet survival post-transplantation, both through a direct effect on islet viability and indirectly through blockade of VEGF-mediated revascularisation.
Collapse
Affiliation(s)
- S E Cross
- Academic Renal Unit, Southmead Hospital, University of Bristol, Bristol, UK.
| | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Emamaullee JA, Stanton L, Schur C, Shapiro AMJ. Caspase inhibitor therapy enhances marginal mass islet graft survival and preserves long-term function in islet transplantation. Diabetes 2007; 56:1289-98. [PMID: 17303806 DOI: 10.2337/db06-1653] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Islet transplantation can provide insulin independence in patients with type 1 diabetes, but islets derived from two or more donors are often required. A significant fraction of the functional islet mass is lost to apoptosis in the immediate posttransplant period. The caspase inhibitor N-benzyloxycabonyl-Val-Ala-Asp-fluoromethyl ketone (zVAD-FMK) has been used therapeutically to prevent apoptosis in experimental animal models of ischemic injury, autoimmunity, and degenerative disease. In the current study, zVAD-FMK therapy was examined in a syngeneic islet transplant model to determine whether caspase inhibition could improve survival of transplanted islets. zVAD-FMK therapy significantly improved marginal islet mass function in renal subcapsular transplantation, where 90% of zVAD-FMK-treated mice became euglycemic with 250 islets, versus 27% of the control animals (P < 0.001). The benefit of zVAD-FMK therapy was further demonstrated after intraportal transplantation, where 75% of zVAD-FMK-treated animals established euglycemia with only 500 islets, and all of the controls remained severely diabetic (P < 0.001). zVAD-FMK pretreatment of isolated islets in the absence of systemic therapy resulted in no significant benefit compared with controls. Long-term follow-up of transplanted animals beyond 1 year posttransplant using glucose tolerance tests confirmed that a short course of zVAD-FMK therapy could prevent metabolic dysfunction of islet grafts over time. In addition, short-term zVAD-FMK treatment significantly reduced posttransplant apoptosis in islet grafts and resulted in preservation of graft insulin reserve over time. Our data suggest that caspase inhibitor therapy will reduce the islet mass required in clinical islet transplantation, perhaps to a level that would routinely allow for insulin independence after single-donor infusion.
Collapse
|
37
|
Rivas-Carrillo JD, Soto-Gutierrez A, Navarro-Alvarez N, Noguchi H, Okitsu T, Chen Y, Yuasa T, Tanaka K, Narushima M, Miki A, Misawa H, Tabata Y, Jun HS, Matsumoto S, Fox IJ, Tanaka N, Kobayashi N. Cell-permeable pentapeptide V5 inhibits apoptosis and enhances insulin secretion, allowing experimental single-donor islet transplantation in mice. Diabetes 2007; 56:1259-67. [PMID: 17287463 DOI: 10.2337/db06-1679] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
OBJECTIVE Treatment of diabetic patients by pancreatic islet transplantation often requires the use of islets from two to four donors to produce insulin independence in a single recipient. Following isolation and transplantation, islets are susceptible to apoptosis, which limits their function and probably long-term islet graft survival. RESEARCH DESIGN AND METHODS To address this issue, we examined the effect of the cell-permeable apoptosis inhibitor pentapeptide Val-Pro-Met-Leu-Lys, V5, on pancreatic islets in a mouse model. RESULTS V5 treatment upregulated expression of anti-apoptotic proteins Bcl-2 and XIAP (X-linked inhibitor of apoptosis protein) by more than 3- and 11-fold and downregulated expression of apoptosis-inducing proteins Bax, Bad, and nuclear factor-kappaB-p65 by 10, 30, and nearly 50%, respectively. Treatment improved the recovered islet mass following collagenase digestion and isolation by 44% and in vitro glucose-responsive insulin secretion nearly fourfold. Following transplantation in streptozotocin-induced diabetic mice, 150 V5-treated islet equivalents functioned as well as 450 control untreated islet equivalents in normalizing blood glucose. CONCLUSIONS These studies indicate that inhibition of apoptosis by V5 significantly improves islet function following isolation and improves islet graft function following transplantation. Use of this reagent in clinical islet transplantation could have a dramatic impact on the number of patients that might benefit from this therapy and could affect long-term graft survival.
Collapse
Affiliation(s)
- Jorge D Rivas-Carrillo
- Department of Surgery, Okayama University Graduate School of Medicine and Dentistry, Shikata-cho, Okayama, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Marcelli-Tourvieille S, Hubert T, Moerman E, Gmyr V, Kerr-Conte J, Nunes B, Dherbomez M, Vandewalle B, Pattou F, Vantyghem MC. In vivo and in vitro effect of sirolimus on insulin secretion. Transplantation 2007; 83:532-8. [PMID: 17353769 DOI: 10.1097/01.tp.0000255679.81792.dd] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The effects of sirolimus on insulin secretion are still debated. Our aim was to investigate the effects of sirolimus, both (1) in vivo in healthy minipigs; and (2) in vitro on human islets. METHODS (1) Ten minipigs were evaluated during three successive stages: (a) basal; (b) at the end of a 4-week period of treatment with sirolimus; and (c) after a 4-week period of wash-out. We evaluated insulin secretion with the acute insulin response (AIR), and glucose tolerance with the glucose disposal rate (GDR). (2) Insulin content, stimulation index, adenosine triphosphate (ATP), and apoptosis were measured in human islets treated in vitro with sirolimus at therapeutic and supratherapeutic concentrations. RESULTS (1) Basal and stimulated insulin levels and GDR increased during sirolimus administration and returned to baseline after a wash-out period; (2) regardless of culture duration, sirolimus dose-dependently decreased apoptosis and increased insulin content. Stimulation indexes and ATP were also significantly enhanced but only at therapeutic concentrations. CONCLUSIONS This study suggests that sirolimus, at plasma-drug concentrations usually targeted in clinical practice, (1) increases basal and stimulated insulin levels in vivo and insulin content in vitro regardless of culture duration; (2) is able to reduce apoptosis. These findings may partly underlie the improved results of islet transplantation.
Collapse
Affiliation(s)
- Sophie Marcelli-Tourvieille
- Department of Endocrinology and Metabolism and Endocrine Surgery, INSERM Unit-M859, Diabetes Cell Therapy, Lille University Hospital, Lille, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Gao R, Ustinov J, Korsgren O, Otonkoski T. Effects of immunosuppressive drugs on in vitro neogenesis of human islets: mycophenolate mofetil inhibits the proliferation of ductal cells. Am J Transplant 2007; 7:1021-6. [PMID: 17391142 DOI: 10.1111/j.1600-6143.2006.01728.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Assuming that neogenesis contributes to long-term function of islet grafts, it is important to study the effects of immunosuppressive drugs on precursor cell proliferation and differentiation. We examined the effects of low-dose immunosuppressive drugs on these processes in vitro. Immunosuppressive drugs, including sirolimus, tacrolimus, mycophenolate mofetil (MMF), daclizumab and their combinations were tested in parallel culture wells through either the expansion phase (5-7 days) or the entire culture period (4-5 weeks). MMF, alone or in combination with sirolimus or tacrolimus, severely hampered duct-cell proliferation by 8-fold during the expansion period, and significantly reduced the total DNA content by about 40% after 5-week culture. After 4-5 week exposure to different drugs, only sirolimus and daclizumab showed no adverse effects on insulin content, whereas significant reductions of 30-60% in insulin content were seen in all other experimental groups. Only tacrolimus decreased the insulin content per DNA, as well as the proportion of insulin-positive cells. In conclusion, MMF has a potent inhibitory effect on neogenesis primarily through an antiproliferative effect on the precursors, whereas tacrolimus mainly affects beta-cell differentiation. Sirolimus and daclizumab have no adverse effects on these parameters. The immunosuppressive protocol may be an important determinant of long-term clinical islet graft function.
Collapse
Affiliation(s)
- R Gao
- Program of Developmental and Reproductive Biology, Biomedicum Helsinki, University of Helsinki, Finland
| | | | | | | |
Collapse
|
40
|
Vantyghem MC, Marcelli-Tourvielle S, Pattou F, Noël C. Effects of non-steroid immunosuppressive drugs on insulin secretion in transplantation. ANNALES D'ENDOCRINOLOGIE 2007; 68:21-7. [PMID: 17316544 DOI: 10.1016/j.ando.2006.11.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2006] [Accepted: 11/27/2006] [Indexed: 11/16/2022]
Abstract
Post-transplantation diabetes (PTD) is a serious complication in organ transplantation: not only does it increase the risk of graft dysfunction; it also increases cardiovascular morbidity and mortality. PTD incidence is correlated with age, non-Caucasian ethnic background, a family history of diabetes, excess weight, hepatitis C infection and steroid boluses for potential rejection. Different mechanisms might explain post-transplantation glucose metabolism disorders: ischemia-reperfusion disorders, whether renal, hepatic or cardiac, are responsible for insulin-resistance, which is increased by post-transplantation steroids; the detrimental effect of non-steroid immunosuppressive drugs on insulin-secretion could also be involved, especially with calcineurin inhibitors. In vivo and in vitro studies have shown that tacrolimus has inhibitory effects on insulin-secretion, while these effects are less obvious for cyclosporin, and were mainly demonstrated in vitro. Mycophenolate has no overt effect on insulin-secretion. Sirolimus and everolimus, two mTOR inhibitors, have shown controversial results in this realm. The effects of sirolimus (most often studied mTOR inhibitor) appear to depend on serum levels, cell type (ss cell or cell line), species (human or animal) and also environmental nutrients. At therapeutic concentrations, a stimulatory effect on insulin secretion was observed on human beta cells. This might explain the success of islet cell transplantation with the Edmonton protocol. Finally, steroids are mainly detrimental because they accentuate insulin resistance whereas anticalcineurins, in particular tacrolimus, lower insulin synthesis.
Collapse
Affiliation(s)
- M-C Vantyghem
- Endocrinology and Metabolism Department, Lille University Hospital, 59037 Lille cedex, France.
| | | | | | | |
Collapse
|
41
|
Abstract
Post-transplant diabetes mellitus (PTDM) has emerged as a major adverse effect of immunosuppressive drugs (ISD). As recipients of organ transplants survive longer, the complications of diabetes mellitus have assumed greater importance. The predominant factor for causing PTDM by corticosteroids seems to be the aggravation of insulin resistance, however several studies have displayed deleterious effects on insulin secretion and beta-cells. Calcineurin inhibitors induce PTDM by a number of mechanisms, including decreased insulin secretion and a direct toxic effect on the pancreatic beta-cells. Recent in vitro studies stress on the increased apoptosis of beta-cells when exposed to these drugs. Studies involving other immunosuppressive agents (mycophenolate mofetil [MMF], sirolimus) are scarcer and lead to conflicting results, while daclizumab seems to have a neutral effect. Clinical studies have consistently shown a greater potential of tacrolimus to induce PTDM compared with cyclosporine. Reducing PTDM incidence is a feasible goal while using corticosteroid-sparing regimens and/or lower tacrolimus trough levels. In patients developing PTDM, conversion from tacrolimus to cyclosporine could improve or reverse glucose tolerance abnormalities. In the absence of well-designed studies in this specific indication, treatment of PTDM is based on the same principles as type 2 diabetes mellitus. Thiazolidinediones do not display any pharmacological interaction with calcineurin inhibitors, but their safety and efficacy in PTDM need to be confirmed in large-scale randomized trials. Use of sulfonylureas has to be cautious regarding the suspected interaction of some of them with calcineurin inhibitors. If needed, insulin regimens have to be adapted in patients who display the particular glycaemic profile of corticosteroid-induced diabetes. Incretin-based therapies, due to their specific action on beta-cell apoptosis and proliferation, raise promises that have to be confirmed in clinical studies. Until methods for inducing specific graft tolerance become available, immunosuppressive regimens should be tailored to the individual patient on the basis of predictive criteria for the development of PTDM.
Collapse
Affiliation(s)
- A Penfornis
- Service d'Endocrinologie-Métabolisme et Diabétologie-Nutrition, Hôpital Jean Minjoz, CHU de Besançon, F-25030 Besançon Cedex, France.
| | | |
Collapse
|
42
|
Hardy OT, Hohmeier HE, Becker TC, Manduchi E, Doliba NM, Gupta RK, White P, Stoeckert CJ, Matschinsky FM, Newgard CB, Kaestner KH. Functional genomics of the beta-cell: short-chain 3-hydroxyacyl-coenzyme A dehydrogenase regulates insulin secretion independent of K+ currents. Mol Endocrinol 2006; 21:765-73. [PMID: 17185391 DOI: 10.1210/me.2006-0411] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Recent advances in functional genomics afford the opportunity to interrogate the expression profiles of thousands of genes simultaneously and examine the function of these genes in a high-throughput manner. In this study, we describe a rational and efficient approach to identifying novel regulators of insulin secretion by the pancreatic beta-cell. Computational analysis of expression profiles of several mouse and cellular models of impaired insulin secretion identified 373 candidate genes involved in regulation of insulin secretion. Using RNA interference, we assessed the requirements of 10 of these candidates and identified four genes (40%) as being essential for normal insulin secretion. Among the genes identified was Hadhsc, which encodes short-chain 3-hydroxyacyl-coenzyme A dehydrogenase (SCHAD), an enzyme of mitochondrial beta-oxidation of fatty acids whose mutation results in congenital hyperinsulinism. RNA interference-mediated gene suppression of Hadhsc in insulinoma cells and primary rodent islets revealed enhanced basal but normal glucose-stimulated insulin secretion. This increase in basal insulin secretion was not attenuated by the opening of the KATP channel with diazoxide, suggesting that SCHAD regulates insulin secretion through a KATP channel-independent mechanism. Our results suggest a molecular explanation for the hyperinsulinemia hypoglycemic seen in patients with SCHAD deficiency.
Collapse
Affiliation(s)
- Olga T Hardy
- Department of Genetics, University of Pennsylvania School of Medicine, 415 Curie Boulevard, 560 Clinical Research Building, Philadelphia, Pennsylvania 19104, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Bussiere CT, Lakey JRT, Shapiro AMJ, Korbutt GS. The impact of the mTOR inhibitor sirolimus on the proliferation and function of pancreatic islets and ductal cells. Diabetologia 2006; 49:2341-9. [PMID: 16896936 DOI: 10.1007/s00125-006-0374-5] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2006] [Accepted: 06/22/2006] [Indexed: 01/31/2023]
Abstract
AIMS/HYPOTHESIS The Edmonton Protocol for islet transplantation has provided hope for type 1 diabetic patients. However, this protocol requires lifelong immunosuppression, specifically sirolimus, a cellular antiproliferate. The effect of sirolimus on human pancreatic ductal cells (HDCs) is not known. This may be important since HDCs are believed to be islet precursors. Since neonatal porcine islets (NPIs), which contain many ductal precursor cells, could be a potential clinical source of islets, we also tested the effects of sirolimus on this tissue. METHODS HDCs (n=4), NPIs (n=9) and human islets (n=5) were cultured with and without sirolimus (20 ng/ml) for 6 days. RESULTS HDCs and NPIs cultured with sirolimus showed a 50 and 28% decrease, respectively, in cell number relative to control (p<0.05). Control cultures expanded 1.65- and 2.44-fold relative to time 0. Decreases in cell number of sirolimus-treated HDCs were not due to apoptosis as measured by TUNEL staining. No functional effects on human islets or NPIs were observed following static incubation with high glucose. Treatment of syngeneically transplanted and naïve BALC/c mice with sirolimus resulted in altered OGTT profiles with prolonged elevation of hyperglycaemia and weight gain. There was no difference in graft and organ insulin content between treatment groups. CONCLUSIONS/INTERPRETATION Our results indicate that sirolimus decreases ductal cell numbers in culture and alters glucose-stimulated insulin secretion in vivo. The administration of sirolimus to islet transplant recipients is likely to impair graft function as a result of decreasing ductal neogenesis and induction of insulin resistance.
Collapse
Affiliation(s)
- C T Bussiere
- Surgical-Medical Research Institute, 1074 Dentistry/Pharmacy Centre, University of Alberta, Edmonton, AB, Canada
| | | | | | | |
Collapse
|
44
|
Emamaullee JA, Shapiro AMJ. Interventional strategies to prevent beta-cell apoptosis in islet transplantation. Diabetes 2006; 55:1907-14. [PMID: 16804057 DOI: 10.2337/db05-1254] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
A substantial proportion of the transplanted islet mass fails to engraft due to death by apoptosis, and a number of strategies have been explored to inhibit beta-cell loss. Inhibition of extrinsic signals of apoptosis (i.e., cFLIP or A20) have been explored in experimental islet transplantation but have only shown limited impact. Similarly, strategies targeted at intrinsic signal inhibition (i.e., BCL-2) have not yet provided substantial improvement in islet engraftment. Recently, investigation of downstream apoptosis inhibitors that block the final common pathway (i.e., X-linked inhibitor of apoptosis protein [XIAP]) have demonstrated promise in both human and rodent models of engraftment. In addition, XIAP has enhanced long-term murine islet allograft survival. The complexities of both intrinsic and extrinsic apoptotic pathway inhibition are discussed in depth.
Collapse
Affiliation(s)
- Juliet A Emamaullee
- Surgical Medical Research Institute, University of Alberta, Edmonton, AB T6G 2N8.
| | | |
Collapse
|
45
|
Araki M, Flechner SM, Ismail HR, Flechner LM, Zhou L, Derweesh IH, Goldfarb D, Modlin C, Novick AC, Faiman C. Posttransplant diabetes mellitus in kidney transplant recipients receiving calcineurin or mTOR inhibitor drugs. Transplantation 2006; 81:335-41. [PMID: 16477217 DOI: 10.1097/01.tp.0000195770.31960.18] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND The aim of this study was to evaluate the incidence and risk factors for posttransplant diabetes mellitus (PTDM; defined as new insulin use and/or new hyperglycemia) in 528 kidney recipients using different immunosuppressive agents. METHODS Maintenance therapy included mycophenolate mofetil or azathioprine plus glucocorticoids in combination with Group I cyclosporine (263); Group II tacrolimus (60); or Group III sirolimus (205). RESULTS The mean follow-up was 39.2 (range 9.0-103.8) months. Overall, the number of patients needing insulin was 7.4% (39/528). The incidences for Groups I, II, and III of 7.6%, 11.7%, and 5.9%, respectively, were not statistically different. Characteristics of patients with PTDM included older age (P=0.007); greater body weight (kg) at transplant, 6 months, and 12 months, respectively (P<0.001); greater BMI (kg/m2) at transplant, 6 months, and 12 months, respectively (P<0.001); more acute rejection episodes 28.2% vs. 13.5% (P=0.012); and increased incidence in African Americans (P=0.03). Multivariable analysis demonstrated increased risk for PTDM (defined as new insulin use) for tacrolimus, (hazard ratio [HR] 3.794, P=0.007); treated rejections (HR 2.491, P=0.0115); age (HR 1.407, P=0.0116); and BMI (HR 1.153, P<0.0001). New insulin use occurred sooner and with less total glucocorticoid dose for tacrolimus patients. If PTDM is defined as all cases of new hyperglycemia, then no immunosuppressive drug group demonstrated an increased risk. CONCLUSION.: The risk for developing PTDM is greatest among older recipients, and those obese at the time of transplant; those given steroid pulse therapy were at exceptionally high-risk. PTDM risk reduction should focus on weight loss in the obese end-stage renal disease population prior to transplant.
Collapse
Affiliation(s)
- Motoo Araki
- Transplant Center/Glickman Urological Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Current literature in diabetes. Diabetes Metab Res Rev 2005; 21:560-7. [PMID: 16240284 DOI: 10.1002/dmrr.604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
47
|
Plesner A, Liston P, Tan R, Korneluk RG, Verchere CB. The X-linked inhibitor of apoptosis protein enhances survival of murine islet allografts. Diabetes 2005; 54:2533-40. [PMID: 16123340 DOI: 10.2337/diabetes.54.9.2533] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Allotransplantation of pancreatic islets represents a promising approach to treat type 1 diabetes. Destruction of beta-cells in islet allografts involves multiple immune mechanisms that lead to activation of caspases and apoptotic cell death. The X-linked inhibitor of apoptosis (XIAP) inhibits apoptosis induced by a variety of triggers, primarily by preventing the activation of caspases. To determine whether XIAP would protect beta-cells from apoptosis, we used a recombinant adenovirus to overexpress XIAP in transformed murine beta-cells and in freshly isolated islets. In vitro cytokine-induced beta-cell death was decreased to baseline levels in XIAP-transduced MIN-6 and NIT-1 cell lines compared with controls. To evaluate the potential of XIAP overexpression to prevent in vivo allogeneic graft rejection, we transduced Balb/c islets ex vivo with XIAP before transplantation into CBA mice with streptozotocin-induced diabetes. We observed that almost all mice receiving allografts of XIAP-expressing islets maintained normoglycemia until the experiment was terminated (45-72 days posttransplant), whereas control mice receiving islets transduced with adenovirus expressing LacZ were hyperglycemic by approximately 17 days posttransplantation due to graft rejection. Immunohistochemistry revealed preservation of beta-cells and clearance of infiltrating immune cells in the XIAP-expressing islet grafts. The in vitro allogeneic response of splenocytes isolated from recipients of XIAP-expressing grafts 8 weeks posttransplant was similar to that seen in nonprimed allogeneic mice, suggesting that XIAP overexpression may lead to the acceptance of islet allografts in diabetic recipients. Long-term protection of islet allografts by XIAP overexpression may enhance the survival of islet transplants in diabetes.
Collapse
Affiliation(s)
- Annette Plesner
- BC Research Institute for Children's and Women's Health, University of British Columbia, Department of Pathology and Laboratory Medicine, Room 2071-950, W. 28th Ave., Vancouver, British Columbia, V5Z 4H4, Canada.
| | | | | | | | | |
Collapse
|
48
|
Emamaullee JA, Rajotte RV, Liston P, Korneluk RG, Lakey JRT, Shapiro AMJ, Elliott JF. XIAP overexpression in human islets prevents early posttransplant apoptosis and reduces the islet mass needed to treat diabetes. Diabetes 2005; 54:2541-8. [PMID: 16123341 DOI: 10.2337/diabetes.54.9.2541] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Edmonton Protocol for treatment of type 1 diabetes requires islets from two or more donors to achieve euglycemia in a single recipient, primarily because soon after portal infusion, the majority of the transplanted cells undergo apoptosis due to hypoxia and hypoxia reperfusion injury. X-linked inhibitor of apoptosis protein (XIAP) is a potent endogenous inhibitor of apoptosis that is capable of blocking the activation of multiple downstream caspases, and XIAP overexpression has previously been shown to enhance engraftment of a murine beta-cell line. In this study, human islets transduced with a XIAP-expressing recombinant adenovirus were resistant to apoptosis and functionally recovered following in vitro stresses of hypoxia and hypoxia with reoxygenation (models reperfusion injury). Furthermore Ad-XIAP transduction dramatically reduced the number of human islets required to reverse hyperglycemia in chemically diabetic immunodeficient mice. These results suggest that by transiently overexpressing XIAP in the immediate posttransplant period, human islets from a single donor might be used to effectively treat two diabetic recipients.
Collapse
Affiliation(s)
- Juliet A Emamaullee
- 1-21 Medical Sciences Building, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2S2, Canada.
| | | | | | | | | | | | | |
Collapse
|