Caspase-3 Inhibitor Prevents Apoptosis of Human Islets Immediately After Isolation and Improves Islet Graft Function

Nakano, Masahiko; Matsumoto, Ippei; Sawada, Toshiya; Ansite, J. D.; Oberbroeckling, Jeremy; Zhang, Hui Jian; Kirchhof, Nicole; Shearer, Jeff; Sutherland, David E.R.; Hering, Bernhard J.

doi:10.1097/00006676-200408000-00004

Cited by 54 publications

(53 citation statements)

References 29 publications

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“…Because the majority of islet death occurs in the first few days posttransplant, we designed our study such that zVAD-FMK would only be administered until day 5 posttransplant, after which point the rate of apoptosis is so minimal that zVAD-FMK therapy would not be justified (21). Our study also implemented a pretransplant incubation period of 2 h in 100 mmol/l zVAD-FMK, which would reduce isolation-induced apoptosis and improve islet survival in the first few hours posttransplant by "loading" the islets with caspase inhibitor (16,17). For all transplant studies, zVAD-FMK was injected into recipients at least 2 h before transplantation, so that the caspase inhibitor would be circulating during the implantation and able to prevent apoptosis immediately.…”

Section: Resultsmentioning

confidence: 99%

“…Montolio et al (16) treated rodent islets in vitro with increasing zVAD-FMK concentrations (100 -500 mol/l) and found only marginal impact after transplantation of a syngeneic marginal mass. Pretreatment of human islets with the selective caspase-3 inhibitor zDEVD-FMK (benzyloxycarbonyl-Asp-Glu-Val-Asp-fluoromethylketone) for up to 2 days improved islet survival during culture and modestly improved islet survival posttransplant into streptozotocin (STZ)-induced diabetic nude mice (17). Based on the positive results obtained in other models of degenerative disease, the impact of therapeutic zVAD-FMK administration on islet survival in vivo after transplantation was investigated in the current study.…”

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confidence: 99%

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Caspase Inhibitor Therapy Enhances Marginal Mass Islet Graft Survival and Preserves Long-Term Function in Islet Transplantation

et al. 2007

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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. Diabetes 56:1289-1298, 2007 T he introduction of the Edmonton Protocol in 2000 led to substantial improvements in 1-year insulin independence rates in clinical islet transplantation (1,2). However, recent long-term follow-up indicates marked reduction in graft function, with only 15% of islet recipients maintaining insulin independence at 5 years (3). Although single-donor islet transplant success has been reported in Minnesota in a limited number of patients, most centers still require at least two donors (4,5). The decline in insulin independence rates seen in clinical islet transplantation is currently not fully characterized, but it is likely to be complex. Detrimental factors include recurrent ␤-cell autoimmunity, subclinical allograft rejection, metabolic exhaustion, chronic islet toxicity of immunosuppressive drugs, and limitations from the intraportal site of islet delivery (2). Strategies designed to maximize survival and minimize immune reactivity of the initial islet mass are likely to have a major impact in enhancing long-term clinical outcomes.A variety of approaches have been explored to prevent apoptotic destruction of islets in the experimental setting, and alth...

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Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

Caspase Inhibitor Therapy Enhances Marginal Mass Islet Graft Survival and Preserves Long-Term Function in Islet Transplantation

et al. 2007

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“…Because a relatively large ␤-cell mass from two to four donor pancreata is needed to achieve normoglycemia in the recipient, it is crucial to develop treatments that would reduce loss of transplanted islets due to apoptosis and maximize use of the limited amount of donor tissue. Isolation of human islets is very stressful on the cells as it disrupts cell-cell and cell-matrix interactions and results in islet apoptosis (9,12,13,17,32,38,39). Alterations in islet fine structure can be seen shortly after isolation and culture in vitro.…”

Section: Discussionmentioning

confidence: 99%

Cell-Permeable Pentapeptide V5 Inhibits Apoptosis and Enhances Insulin Secretion, Allowing Experimental Single-Donor Islet Transplantation in Mice

et al. 2007

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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-V5treatment 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-B-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.

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“…Overexpression of Bcl-2 has been shown to improve survival of endothelial [81,82] and cardiac [83] cells implanted subcutaneously. Caspase inhibition provided to cultured cells, and delivered systemically after injection enhances survival of islet cells [84] and dopaminergic neurons [85,86]. Similarly, treatment of islet cells in vitro (but not after injection) with simvistatin, an HMG-CoA reductase inhibitor, enhanced survival after transplantation [87].…”

Section: Strategies To Increase Cell Survivalmentioning

confidence: 99%

Systems approaches to preventing transplanted cell death in cardiac repair

Robey

Saiget

Reinecke

et al. 2008

Journal of Molecular and Cellular Cardiology

366

294

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Stem cell transplantation may repair the injured heart, but tissue regeneration is limited by death of transplanted cells. Most cell death occurs in the first few days post-transplantation, likely from a combination of ischemia, anoikis and inflammation. Interventions known to enhance transplanted cell survival include heat shock, over-expressing anti-apoptotic proteins, free radical scavengers, anti-inflammatory therapy and co-delivery of extracellular matrix molecules. Combinatorial use of such interventions markedly enhances graft cell survival, but death still remains a significant problem. We review these challenges to cardiac cell transplantation and present an approach to systematically address them.Most anti-death studies use histology to assess engraftment, which is time-and labor-intensive. To increase throughput, we developed two biochemical approaches to follow graft viability in the mouse heart. The first relies on LacZ enyzmatic activity to track genetically modified cells, and the second quantifies human genomic DNA content using repetitive Alu sequences. Both show linear relationships between input cell number and biochemical signal, but require correction for the time lag between cell death and loss of signal. Once optimized, they permit detection of as few as 1 graft cell in 40,000 host cells. Pro-survival effects measured biochemically at three days predict long-term histological engraftment benefits. These methods permitted identification of carbamylated erythropoietin (CEPO) as a pro-survival factor for human embryonic stem cell-derived cardiomyocyte grafts. CEPO's effects were additive to heat shock, implying independent survival pathways. This system should permit combinatorial approaches to enhance graft viability in a fraction of the time required for conventional histology.

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Caspase-3 Inhibitor Prevents Apoptosis of Human Islets Immediately After Isolation and Improves Islet Graft Function

Abstract: Z-DEVD-FMK prevented apoptosis of isolated human islets and improved its function. FBS (10%) improved the islet yield and insulin secretion more than 0.5% HSA.

Cited by 54 publications

References 29 publications

Caspase Inhibitor Therapy Enhances Marginal Mass Islet Graft Survival and Preserves Long-Term Function in Islet Transplantation

Caspase Inhibitor Therapy Enhances Marginal Mass Islet Graft Survival and Preserves Long-Term Function in Islet Transplantation

Cell-Permeable Pentapeptide V5 Inhibits Apoptosis and Enhances Insulin Secretion, Allowing Experimental Single-Donor Islet Transplantation in Mice

Systems approaches to preventing transplanted cell death in cardiac repair

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