OBJECTIVE: Reparixin is an inhibitor of CXCR1/2 chemokine receptor shown to be an effective anti-inflammatory adjuvant in a pilot clinical trial in allotransplant recipients. RESEARCH DESIGN AND METHODS: A phase 3, multicenter, randomized, double-blind, parallel-assignment study (NCT01817959) was conducted in recipients of islet allotransplants randomized (2:1) to reparixin or placebo in addition to immunosuppression. Primary outcome was the area under the curve (AUC) for C-peptide during the mixed-meal tolerance test at day 75 ± 5 after the first and day 365 ± 14 after the last transplant. Secondary end points included insulin independence and standard measures of glycemic control. RESULTS: The intention-to-treat analysis did not show a significant difference in C-peptide AUC at both day 75 (27 on reparixin vs. 18 on placebo, P = 0.99) and day 365 (24 on reparixin vs. 15 on placebo, P = 0.71). There was no statistically significant difference between treatment groups at any time point for any secondary variable. Analysis of patient subsets showed a trend for a higher percentage of subjects retaining insulin independence for 1 year after a single islet infusion in patients receiving reparixin as compared with patients receiving placebo (26.7% vs. 0%, P = 0.09) when antithymocyte globulin was used as induction immunosuppression. CONCLUSIONS: In this first double-blind randomized trial, islet transplantation data obtained with reparixin do not support a role of CXCR1/2 inhibition in preventing islet inflammation-mediated damage.

• MeSH
• časové faktory MeSH
• diabetes mellitus 1. typu farmakoterapie   terapie   MeSH
• dospělí MeSH
• dvojitá slepá metoda MeSH
• imunosupresiva aplikace a dávkování   MeSH
• kombinovaná terapie MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• placebo MeSH
• pooperační období MeSH
• receptory interleukinu-8A antagonisté a inhibitory   MeSH
• receptory interleukinu-8B antagonisté a inhibitory   MeSH
• rozvrh dávkování léků MeSH
• sekrece inzulinu účinky léků   MeSH
• senioři MeSH
• sulfonamidy aplikace a dávkování   škodlivé účinky   farmakologie   MeSH
• transplantace Langerhansových ostrůvků * MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky, fáze III MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH
• Názvy látek
• imunosupresiva MeSH
• placebo MeSH
• receptory interleukinu-8A MeSH
• receptory interleukinu-8B MeSH
• reparixin MeSH Prohlížeč
• sulfonamidy MeSH

Instant Blood-Mediated Inflammatory Reaction (IBMIR) is a major cause of graft loss during pancreatic islet transplantation, leading to a low efficiency of this treatment method and significantly limiting its broader clinical use. Within the procedure, transplanted islets obstruct intrahepatic portal vein branches and consequently restrict blood supply of downstream lying liver tissue, resulting typically in ischemic necrosis. The extent of ischemic lesions is influenced by mechanical obstruction and inflammation, as well as subsequent recanalization and regeneration capacity of recipient liver tissue. Monitoring of immediate liver perfusion impairment, which is directly related to the intensity of post-transplant inflammation and thrombosis (IBMIR), is essential for improving therapeutic and preventive strategies to improve overall islet graft survival. In this study, we present a new experimental model enabling direct quantification of liver perfusion impairment after pancreatic islet transplantation using ligation of hepatic arteries followed by contrast-enhanced magnetic resonance imaging (MRI). The ligation of hepatic arteries prevents the contrast agent from circumventing the portal vein obstruction and enables to discriminate between well-perfused and non-perfused liver tissue. Here we demonstrate that the extent of liver ischemia reliably reflects the number of transplanted islets. This model represents a useful tool for in vivo monitoring of biological effect of IBMIR-alleviating interventions as well as other experiments related to liver ischemia. This technical paper introduces a novel technique and its first application in experimental animals.

• Klíčová slova
• IBMIR, MRI, Pancreatic islet transplantation, instant blood-mediated inflammatory reaction, liver ischemia, magnetic resonance imaging,
• MeSH
• embolie * komplikace   diagnóza   MeSH
• ischemie * diagnostické zobrazování   etiologie   MeSH
• játra * krevní zásobení   diagnostické zobrazování   patologie   MeSH
• krysa rodu Rattus MeSH
• magnetická rezonanční angiografie metody   MeSH
• přežívání štěpu MeSH
• reprodukovatelnost výsledků MeSH
• teoretické modely MeSH
• transplantace Langerhansových ostrůvků škodlivé účinky   MeSH
• vena portae * MeSH
• vylepšení obrazu metody   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Magnetoliposomes (MLs) were synthesized and tested for longitudinal monitoring of transplanted pancreatic islets using magnetic resonance imaging (MRI) in rat models. The rat insulinoma cell line INS-1E and isolated pancreatic islets from outbred and inbred rats were used to optimize labeling conditions in vitro. Strong MRI contrast was generated by islets exposed to 50 µg Fe/ml for 24 hours without any increased cell death, loss of function or other signs of toxicity. In vivo experiments showed that pancreatic islets (50-1000 units) labeled with MLs were detectable for up to 6 weeks post-transplantation in the kidney subcapsular space. Islets were also monitored for two weeks following transplantation through the portal vein of the liver. Hereby, islets labeled with MLs and transplanted under the left kidney capsule were able to correct hyperglycemia and had stable MRI signals until nephrectomy. Interestingly, in vivo MRI of streptozotocin induced diabetic rats transplanted with allogeneic islets demonstrated loss of MRI contrast between 7-16 days, indicative of loss of islet structure. MLs used in this study were not only beneficial for monitoring the location of transplanted islets in vivo with high sensitivity but also reported on islet integrity and hereby indirectly on islet function and rejection.

• MeSH
• experimentální diabetes mellitus chemicky indukované   metabolismus   patologie   MeSH
• hyperglykemie metabolismus   patologie   MeSH
• inzulin metabolismus   MeSH
• játra metabolismus   patologie   MeSH
• kontrastní látky metabolismus   MeSH
• krysa rodu Rattus MeSH
• kultivované buňky MeSH
• Langerhansovy ostrůvky metabolismus   patologie   MeSH
• longitudinální studie MeSH
• magnetická rezonanční tomografie metody   MeSH
• magnetické nanočástice aplikace a dávkování   MeSH
• potkani inbrední LEW MeSH
• potkani Wistar MeSH
• streptozocin farmakologie   MeSH
• transplantace Langerhansových ostrůvků metody   MeSH
• vena portae metabolismus   patologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• inzulin MeSH
• kontrastní látky MeSH
• magnetické nanočástice MeSH
• streptozocin MeSH

Subcutaneously implanted polymeric scaffolds represent an alternative transplantation site for pancreatic islets (PIs) with the option of vascularisation enhancement by mesenchymal stem cells (MSC). Nevertheless, a proper timing of the transplantation steps is crucial. In this study, scaffolds supplemented with plastic rods were implanted into diabetic rats and two timing schemes for subsequent transplantation of bioluminescent PIs (4 or 7 days after rod removal) were examined by multimodal imaging. The cavities were left to heal spontaneously or with 10 million injected MSCs. Morphological and vascularisation changes were examined by MRI, while the localisation and viability of transplanted islets were monitored by bioluminescence imaging. The results show that PIs transplanted 4 days after rod removal showed the higher optical signal and vascularisation compared to transplantation after 7 days. MSCs slightly improved vascularisation of the graft but hindered therapeutic efficiency of PIs. Long-term glycaemia normalisation (4 months) was attained in 80% of animals. In summary, multimodal imaging confirmed the long-term survival and function of transplanted PIs in the devices. The best outcome was reached with PIs transplanted on day 4 after rod removal and therefore the suggested protocol holds a potential for further applications.

• MeSH
• alografty MeSH
• experimentální diabetes mellitus * diagnostické zobrazování   chirurgie   MeSH
• krysa rodu Rattus MeSH
• Langerhansovy ostrůvky * krevní zásobení   diagnostické zobrazování   metabolismus   patologie   MeSH
• luminiscenční měření * MeSH
• mezenchymální kmenové buňky metabolismus   patologie   MeSH
• potkani transgenní MeSH
• přežívání štěpu * MeSH
• tkáňové podpůrné struktury * MeSH
• transplantace Langerhansových ostrůvků metody   MeSH
• transplantace mezenchymálních kmenových buněk MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

PURPOSE: An artificial site for cell or pancreatic islet transplantation can be created using a polymeric scaffold, even though it suffers subcutaneously from improper vascularisation. A sufficient blood supply is crucial for graft survival and function and can be enhanced by transplantation of mesenchymal stem cells (MSCs). The purpose of this study was to assess the effect of syngeneic MSCs on neoangiogenesis and cell engraftment in an artificial site by multimodal imaging. PROCEDURES: MSCs expressing a gene for luciferase were injected into the artificial subcutaneous site 7 days after scaffold implantation. MRI experiments (anatomical and dynamic contrast-enhanced images) were performed on a 4.7-T scanner using gradient echo sequences. Bioluminescent images were acquired on an IVIS Lumina optical imager. Longitudinal examination was performed for 2 months, and one animal was monitored for 16 months. RESULTS: We confirmed the long-term presence (lasting more than 16 months) of viable donor cells inside the scaffolds using bioluminescence imaging with an optical signal peak appearing on day 3 after MSC implantation. When compared to controls, the tissue perfusion and vessel permeability in the scaffolds were significantly improved at the site with MSCs with a maximal peak on day 9 after MSC transplantation. CONCLUSIONS: Our data suggest that the maximal signal obtained by bioluminescence and magnetic resonance imaging from an artificially created site between 3 and 9 days after MSC transplantation can predict the optimal time range for subsequent cellular or tissue transplantation, including pancreatic islets.

• Klíčová slova
• Bioluminescence, DCE, Dynamic contrast-enhanced MRI, Magnetic resonance imaging, Mesenchymal stem cells, Vascularisation,
• MeSH
• kontrastní látky MeSH
• luminiscenční měření MeSH
• magnetická rezonanční tomografie MeSH
• mezenchymální kmenové buňky cytologie   MeSH
• multimodální zobrazování * MeSH
• potkani inbrední LEW MeSH
• regionální krevní průtok fyziologie   MeSH
• reprodukovatelnost výsledků MeSH
• tkáňové podpůrné struktury MeSH
• transplantace mezenchymálních kmenových buněk * MeSH
• umělé buňky * MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kontrastní látky MeSH

Direct reprogramming of pancreatic nonendocrine cells into insulin-producing β-cells represents a promising approach for the treatment of insulin-dependent diabetes. However, its clinical application is limited by the potential for insertional mutagenesis associated with the viral vectors currently used for cell reprogramming. With the aim of developing a nonintegrative reprogramming strategy for derivation of insulin-producing cells, here, we evaluated a new approach utilizing synthetic messenger RNAs encoding reprogramming transcription factors. Administration of synthetic mRNAs encoding three key transcription regulators of β-cell differentiation-Pdx1, Neurogenin3, and MafA-efficiently reprogrammed the pancreatic exocrine cells into insulin-producing cells. In addition to the insulin genes expression, the synthetic mRNAs also induced the expressions of genes important for proper pancreatic β-cell function, including Sur1, Kir6.2, Pcsk1, and Pcsk2. Pretreating cells with the chromatin-modifying agent 5-Aza-2'-deoxycytidine further enhanced reprogramming efficiency, increasing the proportion of insulin-producing cells from 3.5 ± 0.9 to 14.3 ± 1.9% (n = 4). Moreover, 5-Aza-2'-deoxycytidine pretreatment enabled the reprogrammed cells to respond to glucose challenge with increased insulin secretion. In conclusion, our results support that the reprogramming of pancreatic exocrine cells into insulin-producing cells, induced by synthetic mRNAs encoding pancreatic transcription factors, represents a promising approach for cell-based diabetes therapy.

• Publikační typ
• časopisecké články MeSH