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- Goto, Masafumi, et al.
(författare)
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Dissecting the instant blood-mediated inflammatory reaction in islet xenotransplantation
- 2008
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Ingår i: Xenotransplantation. - : Wiley. - 0908-665X .- 1399-3089. ; 15:4, s. 225-234
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A massive destruction of transplanted tissue occurs immediately following transplantation of pancreatic islets from pig to non-human primates. The detrimental instant blood-mediated inflammatory reaction (IBMIR), triggered by the porcine islets, is a likely explanation for this tissue loss. This reaction may also be responsible for mediating an adaptive immune response in the recipient that requires a heavy immunosuppressive regimen. MATERIALS AND METHODS: Low molecular weight dextran sulfate (LMW-DS) and the complement inhibitor Compstatin were used in a combination of in vitro and in vivo studies designed to dissect the xenogeneic IBMIR in a non-human primate model of pancreatic islet transplantation. Adult porcine islets (10,000 IEQs/kg) were transplanted intraportally into three pairs of cynomolgus monkeys that had been treated with LMW-DS or heparin (control), and the effects on the IBMIR were characterized. Porcine islets were also incubated in human blood plasma in vitro to assess complement inhibition by LMW-DS and Compstatin. RESULTS: Morphological scoring and immunohistochemical staining revealed that the severe islet destruction and macrophage, neutrophilic granulocyte, and T-cell infiltration observed in the control (heparin-treated) animals were abrogated in the LMW-DS-treated monkeys. Both coagulation and complement activation were significantly reduced in monkeys treated with LMW-DS, but IgM and complement fragments were still found on the islet surface. This residual complement activation could be inhibited by Compstatin in vitro. CONCLUSIONS: The xenogeneic IBMIR in this non-human primate model is characterized by an immediate binding of antibodies that triggers deleterious complement activation and a subsequent clotting reaction that leads to further complement activation. The effectiveness of LMW-DS (in vivo and in vitro) and Compstatin (in vitro) in inhibiting this IBMIR provides the basis for a protocol that can be used to abrogate the IBMIR in pig-human clinical islet transplantation.
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| 3. |
- Kirwan, Gemma M, et al.
(författare)
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Building Multivariate Systems Biology Models
- 2012
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Ingår i: Analytical Chemistry. - Washington : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 84:16, s. 7064-7071
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Tidskriftsartikel (refereegranskat)abstract
- Systems biology methods using large-scale "omics" data sets face unique challenges: integrating and analyzing near limitless data space, while recognizing and removing systematic variation or noise. Herein we propose a complementary multivariate analysis workflow to both integrate "omics" data from disparate sources and analyze the results for specific and unique sample correlations. This workflow combines principal component analysis (PCA), orthogonal projections to latent structures discriminate analysis (OPLS-DA), orthogonal 2 projections to latent structures (O2PLS), and shared and unique structures (SUS) plots. The workflow is demonstrated using data from a study in which ApoE3Leiden mice were fed an atherogenic diet consisting of increasing cholesterol levels followed by therapeutic intervention (fenofibrate, rosuvastatin, and LXR activator T-0901317). The levels of structural lipids (lipidomics) and free fatty acids in liver were quantified via liquid chromatography-mass spectrometry (LC-MS). The complementary workflow identified diglycerides as key hepatic metabolites affected by dietary cholesterol and drug intervention. Modeling of the three therapeutics for mice fed a high-cholesterol diet further highlighted diglycerides as metabolites of interest in atherogenesis, suggesting a role in eliciting chronic liver inflammation. In particular, O2PLS-based SUS2 plots showed that treatment with T-0901317 or rosuvastatin returned the diglyceride profile in high-cholesterol-fed mice to that of control animals.
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| 5. |
- Tokodai, Kazuaki, et al.
(författare)
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Attenuation of Cross-Talk Between the Complement and Coagulation Cascades by C5a Blockade Improves Early Outcomes After Intraportal Islet Transplantation
- 2010
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Ingår i: Transplantation. - 0041-1337 .- 1534-6080. ; 90:12, s. 1358-1365
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Tidskriftsartikel (refereegranskat)abstract
- Background. Complement 5a factor (C5a) elicits a broad range of proinflammatory effects, including chemotaxis of inflammatory cells and cytokine release. C5a is also linked to the coagulant activity in autoimmune diseases. Therefore, C5a most likely plays a crucial role in the instant blood-mediated inflammatory reaction. Methods. Intraportal transplantation of 2.5 islet equivalents/g of syngeneic rat islet grafts was performed in two groups of streptozotocin-induced diabetic rats: controls and C5a inhibitory peptide (C5aIP)-treated group. Results. The thrombin-antithrombin complex was significantly suppressed in the C5aIP group (P = 0.003), and both the curative rate and the glucose tolerance were significantly improved in the C5aIP group (P < 0.05 and P < 0.005, respectively). Expression of tissue factor on granulocytes in recipient livers was up-regulated 1 h after islet infusion (P < 0.0001), which was significantly suppressed by C5aIP (P < 0.005). However, C5aIP was unable to regulate tissue factor expression on isolated islets. Furthermore, no differences were detected between the groups, regarding infiltration of CD11b-positive cells and deposition of C5b-9 on the islet grafts. Conclusions. These data suggest that C5aIP attenuates cross-talk between the complement and coagulation cascades through suppressing up-regulation of tissue factor expression on leukocytes in recipient livers but not on islet grafts, a process leading to improvement in islet engraftment. Therefore, C5aIP in combination with conventional anticoagulants could be a strong candidate strategy to control the instant blood-mediated inflammatory reaction induced in clinical islet transplantation.
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| 6. |
- Wheelock, Craig E., et al.
(författare)
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Bioinformatics strategies for the analysis of lipids
- 2009
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Ingår i: Methods in Molecular Biology. - Totowa, NJ : Springer. - 1064-3745 .- 1940-6029. ; 580, s. 339-368
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Tidskriftsartikel (refereegranskat)abstract
- Owing to their importance in cellular physiology and pathology as well as to recent technological advances, the study of lipids has reemerged as a major research target. However, the structural diversity of lipids presents a number of analytical and informatics challenges. The field of lipidomics is a new postgenome discipline that aims to develop comprehensive methods for lipid analysis, necessitating concomitant developments in bioinformatics. The evolving research paradigm requires that new bioinformatics approaches accommodate genomic as well as high-level perspectives, integrating genome, protein, chemical and network information. The incorporation of lipidomics information into these data structures will provide mechanistic understanding of lipid functions and interactions in the context of cellular and organismal physiology. Accordingly, it is vital that specific bioinformatics methods be developed to analyze the wealth of lipid data being acquired. Herein, we present an overview of the Kyoto Encyclopedia of Genes and Genomes (KEGG) database and application of its tools to the analysis of lipid data. We also describe a series of software tools and databases (KGML-ED, VANTED, MZmine, and LipidDB) that can be used for the processing of lipidomics data and biochemical pathway reconstruction, an important next step in the development of the lipidomics field.
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