Hyperthermic Preconditioning Protects Pig Islet Grafts from Early Inflammation but Enhances Rejection in Immunocompetent Mice

Brandhorst, Daniel; Brandhorst, Heide; Kumarasamy, Vidya; Maataoui, Adel; Alt, A.; Brendel, Mathias D.; Bretzel, Reinhard G.

doi:10.3727/000000003771000200

Cited by 15 publications

(15 citation statements)

References 27 publications

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“…Western blot analysis in isolated pig islets demonstrated that the heat-induced HSP70 overexpression corIn summary, the present study demonstrates that WBH is less effective than in vitro HS to induce persisrelate with an increased expression of Bax (10). In the present study it was found, that rat islets expressed a tent HSP70 overexpression in rat islets needed for increased islet resistance against inflammatory mediators.…”

Section: Rt-pcr Analysissupporting

confidence: 49%

“…simultaneously trigger mechanisms for protection and apoptosis (10). After isolation islets are exposed to a In order to evaluate whether proapoptotic pathways were stimulated by different procedures applied for hynonphysiological ambient environment, representing a proapoptotic stimulus for this endocrine tissue (21).…”

Section: Rt-pcr Analysismentioning

confidence: 99%

“…Binding of vitro HS were treated in the same manner with regard primary antibodies was then visualized by a 1-h reaction to timing and dosage of anesthesia. For in vitro HS at room temperature with a mixture of donkey anti-goat-(n = 25) quantified aliquots of freshly purified islets RhodRedX and donkey anti-mouse-FITC (Jackson Imwere suspended in supplemented TCM 199 and incumunoResearch, West Groove, PA, USA) diluted 1:400 bated for 45 min in a water bath at 42°C prior to 12-with phosphate-buffered saline (PBS) containing 5% rat h culture at 37°C in humidified atmosphere (10). This serum (Jackson ImmunoResearch).…”

Section: Hyperthermic Preconditioningmentioning

confidence: 99%

“…However, previous observations in isolated pig islets demonstrated that the induction of HSPs by hyperthermic stress The production of isolated islets is associated with numerous variables that determine the critical islet mass simultaneously induces two distinct processes with protective or apoptotic characteristics, which can finally deto induce long-term insulin independence in type 1 diabetic recipients (25). Detrimental factors such as brain teriorate posttransplant function (10). As a consequence, reduction of hyperthermia not only prevented a signifideath, surgical trauma, or enzymatic pancreas digestion are characterized by the activation of proinflammatory cant upregulation of proapoptotic proteins such as Bax, Fas, or DNA fragmentation factor, but minimized overand proapoptotic mechanisms affecting islet yield and viability (1, 13,24,28).…”

Section: Introductionmentioning

confidence: 99%

“…As a consequence, reduction of hyperthermia not only prevented a signifideath, surgical trauma, or enzymatic pancreas digestion are characterized by the activation of proinflammatory cant upregulation of proapoptotic proteins such as Bax, Fas, or DNA fragmentation factor, but minimized overand proapoptotic mechanisms affecting islet yield and viability (1, 13,24,28). After intraportal transplantation expression of HSP27, HSP70, or HSP90 as well (7,10). In this context it should be considered that isolated islets islets are exposed to immediate nonspecific inflammatory reactions, reducing islet graft function (5,9).…”

Section: Introductionmentioning

confidence: 99%

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Effect of Pretransplant Preconditioning by Whole Body Hyperthermia on Islet Graft Survival

Brandhorst

Olbrich²,

Neumann

et al. 2007

Cell Transplant

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Previous observations in heat-shocked pig islets revealed the ambivalent character of the stress response simultaneously inducing processes of protection and apoptosis. To clarify whether the proapoptotic character of the stress response is reduced in heat-exposed islets still embedded in their native environment, hyperthermia was performed in the present study either as whole body hyperthermia (WBH) prior to pancreas resection or as in vitro heat shock (HS) after isolation. HS (42°C/45 min) was induced in donors 12 h before isolation (WBH, n = 32) or in freshly isolated islets prior to 12 h of culture at 37°C (in vitro HS, n = 25). Islets continuously incubated at 37°C served as controls (n = 34). Proinflammatory treatment was performed with H 2 O 2 , DETA-NO, or a combination of IL-1β, TNF-α, and IFN-γ. Quality assessment included islet yield, viability staining, static glucose incubation, and nude mouse transplantation. WBH was significantly less effective than in vitro HS to induce HSP70 overexpression and to increase islet resistance against inflammatory mediators. Although characterized by an unaltered Bax to Bcl-2 ratio, islets subjected to WBH partially failed to restore sustained normoglycemia in diabetic nude mice. The inflammatory response observed in the pancreas of WBH-treated rats was associated with significantly reduced viability that seems to have a higher predictive value for posttransplant outcome compared to islet in vitro function or mitochondrial activity. In contrast, in vitro HS significantly decreased transcript levels of Bcl-2, but did not affect posttransplant function compared to sham-treated islets. These findings suggest that WBH is primarily associated with increased necrosis as a secondary tissue type-specific effect of pancreas damage while in vitro HS mainly induces apoptosis.

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Section: Rt-pcr Analysissupporting

confidence: 49%

Section: Rt-pcr Analysismentioning

confidence: 99%

Section: Hyperthermic Preconditioningmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Effect of Pretransplant Preconditioning by Whole Body Hyperthermia on Islet Graft Survival

Brandhorst

Olbrich²,

Neumann

et al. 2007

Cell Transplant

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Hyperbaric oxygenation of UW solution positively impacts on the energy state of porcine pancreatic tissue*

et al. 2011

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Background: Pancreatic islet transplantation is a promising option for the treatment of diabetic patients; xenotransplantation of porcine islet cells would be a possibility to overcome the shortage of donor organs. Usually the donor pancreas is preserved with University of Wisconsin (UW) solution. A large number of reports have shown that the two-layer method (TLM), which employs oxygenated perfluorochemical and UW solution, is superior to simple cold storage. However, the extensive use of TLM is cost intensive and there is evidence that TLM only oxygenates small parts of the organ preserved. Another possibility to increase the oxygen supply during organ preservation would be the use of hyperbaric oxygenation (HBO) which increases the oxygen tension in fluids. The aim of this study was to evaluate the effect of pre-oxygenation of different preservation solutions on organ quality in terms of high energy phosphate levels as well as the occurrence of apoptosis and the induction of heat shock proteins and nitrosative stress induced cell death in porcine pancreatic tissue.Methods: Porcine pancreatic tissue was preserved in different preservation solutions with or without pre-oxygenation for 6 hours of cold ischemic time (CIT). Then, tissue specimens were harvested and high energy phosphate levels were determined by HPLC. Moreover, immunohistochemistry was performed in order to detect occurrence of apoptosis, heat shock protein 70 (HSP70) as well as nitrosative stress induced cell death.Results: Organs stored in pre-oxygenated UW solution showed best results in terms of high energy phosphate levels; apoptotic cells per islet as well as HSP70 positivity were significantly less when compared to simple UW storage and all other organ preservation solutions with or without pre-oxygenation.Conclusions: Pre-oxygenation of UW solution is a simple and promising method to improve islet cell quality after cold organ storage. However, further in vitro experiments have to be performed in order to confirm these findings.

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Anti-caspase-3 preconditioning increases proinsulin secretion and deteriorates posttransplant function of isolated human islets

Brandhorst

Maataoui

et al. 2013

Apoptosis

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Human islet isolation is associated with adverse conditions inducing apoptosis and necrosis. The aim of the present study was to assess whether antiapoptotic preconditioning can improve in vitro and posttransplant function of isolated human islets. A dose-finding study demonstrated that 200 μmol/L of the caspase-3 inhibitor Ac-DEVD-CMK was most efficient to reduce the expression of activated caspase-3 in isolated human islets exposed to severe heat shock. Ac-DEVD-CMK-pretreated or sham-treated islets were transplanted into immunocompetent or immunodeficient diabetic mice and subjected to static glucose incubation to measure insulin and proinsulin secretion. Antiapoptotic pretreatment significantly deteriorated graft function resulting in elevated nonfasting serum glucose when compared to sham-treated islets transplanted into diabetic nude mice (p< 0.01) and into immunocompetent mice (p < 0.05). Ac-DEVD-CMK pretreatment did not significantly change basal and glucose-stimulated insulin release compared to sham-treated human islets but increased the proinsulin release at high glucose concentrations (20 mM) thus reducing the insulin-to-proinsulin ratio in preconditioned islets (p < 0.05). This study demonstrates that the caspase-3 inhibitor Ac-DEVD-CMK interferes with proinsulin conversion in preconditioned islets reducing their potency to cure diabetic mice. The mechanism behind this phenomenon is unclear so far but may be related to the ketone CMK linked to the Ac-DEVD molecule. Further studies are required to identify biocompatible caspase inhibitors suitable for islet preconditioning.

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Hyperthermic Preconditioning Protects Pig Islet Grafts from Early Inflammation but Enhances Rejection in Immunocompetent Mice

Cited by 15 publications

References 27 publications

Effect of Pretransplant Preconditioning by Whole Body Hyperthermia on Islet Graft Survival

Effect of Pretransplant Preconditioning by Whole Body Hyperthermia on Islet Graft Survival

Hyperbaric oxygenation of UW solution positively impacts on the energy state of porcine pancreatic tissue*

Anti-caspase-3 preconditioning increases proinsulin secretion and deteriorates posttransplant function of isolated human islets

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