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991.
Haustein SV Kolterman AJ Sundblad JJ Fechner JH Knechtle SJ 《ILAR journal / National Research Council, Institute of Laboratory Animal Resources》2008,49(2):209-219
Nonhuman primates, primarily rhesus macaques (Macaca mulatta), cynomolgus macaques (Macaca fascicularis), and baboons (Papio spp.), have been used extensively in research models of solid organ transplantation, mainly because the nonhuman primate (NHP) immune system closely resembles that of the human. Nonhuman primates are also frequently the model of choice for preclinical testing of new immunosuppressive strategies. But the management of post-transplant nonhuman primates is complex, because it often involves multiple immunosuppressive agents, many of which are new and have unknown effects. Additionally, the resulting immunosuppression carries a risk of infectious complications, which are challenging to diagnose. Last, because of the natural tendency of animals to hide signs of weakness, infectious complications may not be obvious until the animal becomes severely ill. For these reasons the diagnosis of infectious complications is difficult among post-transplant NHPs. Because most nonhuman primate studies in organ transplantation are quite small, there are only a few published reports concerning infections after transplantation in nonhuman primates. Based on our survey of these reports, the incidence of infection in NHP transplant models is 14%. The majority of reports suggest that many of these infections are due to reactivation of viruses endemic to the primate species, such as cytomegalovirus (CMV), polyomavirus, and Epstein-Barr virus (EBV)-related infections. In this review, we address the epidemiology, pathogenesis, role of prophylaxis, clinical presentation, and treatment of infectious complications after solid organ transplantation in nonhuman primates. 相似文献
992.
993.
Identification of small signalling molecules promoting cardiac-specific differentiation of mouse embryonic stem cells. 总被引:1,自引:0,他引:1
Agapios Sachinidis Silke Schwengberg Rita Hippler-Altenburg Devi Mariappan Naidu Kamisetti Bianca Seelig Albrecht Berkessel Jurgen Hescheler 《Cellular physiology and biochemistry》2006,18(6):303-314
Identification of signalling cascades involved in cardiomyogenesis is crucial for optimising the generation of cardiomyocytes from embryonic stem cells (ES cells) (in vitro). We used a transgenic ES cell lineage expressing enhanced green fluorescent protein (EGFP) under the control of the alpha-myosin heavy chain (alpha-MHC) promoter (palphaMHC-EGFP) to investigate the effects of 33 small molecules interfering with several signalling cascades on cardiomyogenesis. Interestingly, the L-Type Ca2+ channel blocker Verapamil as well as Cyclosporin, an inhibitor of the protein phosphatase 2B, exerted the most striking pro-cardiomyogenic effect. Forskolin (adenylate cyclase stimulator) exerted the most striking anti-cardiomyogenic effect. The cardiomyogenic effect of Cyclosporin and Verapamil correlated with an expression of early cardiac markers Nkx2.5 and GATA4.Compared to the effects on late developmental stage embryoid bodies (EBs) stimulation of early developmental stage EBs (1-day old) with Verapamil or Cyclosporin for 48 h resulted in a potent cardiomyogenic effect. Accordingly, enhanced expression of alpha-MHC mRNA and EGFP mRNA was observed after stimulation of the early developmental stage EBs for 48 h. No expression of alpha-smooth muscle actin or platelet endothelial cell adhesion molecule-1 (PECM-1) as well as of neuronal genes (Nestin, Neurofilament H) has been observed demonstrating a preferentially pro-cardiomyogenic effect by both molecules. 相似文献
994.
Fronz K Otto S Kölbel K Kühn U Friedrich H Schierhorn A Beck-Sickinger AG Ostareck-Lederer A Wahle E 《The Journal of biological chemistry》2008,283(29):20408-20420
The mammalian nuclear poly(A)-binding protein, PABPN1, carries 13 asymmetrically dimethylated arginine residues in its C-terminal domain. By fractionation of cell extracts, we found that protein-arginine methyltransferases (PRMTs)-1, -3, and -6 are responsible for the modification of PABPN1. Recombinant PRMT1, -3, and -6 also methylated PABPN1. Our data suggest that these enzymes act on their own, and additional polypeptides are not involved in recognizing PABPN1 as a substrate. PRMT1 is the predominant methyltransferase acting on PABPN1. Nevertheless, PABPN1 was almost fully methylated in a Prmt1(-/-) cell line; thus, PRMT3 and -6 suffice for methylation. In contrast to PABPN1, the heterogeneous nuclear ribonucleoprotein (hnRNP) K is selectively methylated only by PRMT1. Efficient methylation of synthetic peptides derived from PABPN1 or hnRNP K suggested that PRMT1, -3, and -6 recognize their substrates by interacting with local amino acid sequences and not with additional domains of the substrates. However, the use of fusion proteins suggested that the inability of PRMT3 and -6 to modify hnRNP K is because of structural masking of the methyl-accepting amino acid sequences by neighboring domains. Mutations leading to intracellular aggregation of PABPN1 cause the disease oculopharyngeal muscular dystrophy. The C-terminal domain containing the methylated arginine residues is known to promote PAPBN1 self-association, and arginine methylation has been reported to inhibit self-association of an orthologous protein. Thus, arginine methylation might be relevant for oculopharyngeal muscular dystrophy. However, in two different types of assays we have been unable to detect any effect of arginine methylation on the aggregation of bovine PABPN1. 相似文献
995.
Myofibrils of the skeletal muscle are comprised of sarcomeres that generate force by contraction when myosin-rich thick filaments slide past actin-based thin filaments. Surprisingly little is known about the molecular processes that guide sarcomere assembly in vivo, despite deficits within this process being a major cause of human disease. To overcome this knowledge gap, we undertook a forward genetic screen coupled with reverse genetics to identify genes required for vertebrate sarcomere assembly. In this screen, we identified a zebrafish mutant with a nonsense mutation in mob4. In Drosophila, mob4 has been reported to play a role in spindle focusing as well as neurite branching and in planarians mob4 was implemented in body size regulation. In contrast, zebrafish mob4geh mutants are characterised by an impaired actin biogenesis resulting in sarcomere defects. Whereas loss of mob4 leads to a reduction in the amount of myofibril, transgenic expression of mob4 triggers an increase. Further genetic analysis revealed the interaction of Mob4 with the actin-folding chaperonin TRiC, suggesting that Mob4 impacts on TRiC to control actin biogenesis and thus myofibril growth. Additionally, mob4geh features a defective microtubule network, which is in-line with tubulin being the second main folding substrate of TRiC. We also detected similar characteristics for strn3-deficient mutants, which confirmed Mob4 as a core component of STRIPAK and surprisingly implicates a role of the STRIPAK complex in sarcomerogenesis. 相似文献
996.
997.
Julia Gansler Miriam Jaax Silke Leiting Bettina Appel Andreas Greinacher Silvia Fischer Klaus T. Preissner 《PloS one》2012,7(11)
Nucleic acids, especially extracellular RNA, are exposed following tissue- or vessel damage and have previously been shown to activate the intrinsic blood coagulation pathway in vitro and in vivo. Yet, no information on structural requirements for the procoagulant activity of nucleic acids is available. A comparison of linear and hairpin-forming RNA- and DNA-oligomers revealed that all tested oligomers forming a stable hairpin structure were protected from degradation in human plasma. In contrast to linear nucleic acids, hairpin forming compounds demonstrated highest procoagulant activities based on the analysis of clotting time in human plasma and in a prekallikrein activation assay. Moreover, the procoagulant activities of the DNA-oligomers correlated well with their binding affinity to high molecular weight kininogen, whereas the binding affinity of all tested oligomers to prekallikrein was low. Furthermore, four DNA-aptamers directed against thrombin, activated protein C, vascular endothelial growth factor and nucleolin as well as the naturally occurring small nucleolar RNA U6snRNA were identified as effective cofactors for prekallikrein auto-activation. Together, we conclude that hairpin-forming nucleic acids are most effective in promoting procoagulant activities, largely mediated by their specific binding to kininogen. Thus, in vivo application of therapeutic nucleic acids like aptamers might have undesired prothrombotic or proinflammatory side effects. 相似文献
998.
Abdul Mannan Baru Venkateswaran Ganesh Jayendra Kumar Krishnaswamy Christina Hesse Christopher Untucht Silke Glage Georg Behrens Christian Thomas Mayer Franz Puttur Tim Sparwasser 《PloS one》2012,7(10)
Regulatory T cells (Tregs) play a non-redundant role in maintenance of immune homeostasis. This is achieved by suppressing both, priming of naïve cells and effector cell functions. Although Tregs have been implicated in modulating allergic immune responses, their influence on distinct phases of development of allergies remains unclear. In this study, by using bacterial artificial chromosome (BAC)-transgenic Foxp3-DTR (DEREG) mice we demonstrate that the absence of Foxp3+ Tregs during the allergen challenge surprisingly does not exacerbate allergic airway inflammation in BALB/c mice. As genetic disposition due to strain specificity may contribute significantly to development of allergies, we performed similar experiment in C57BL/6 mice, which are less susceptible to allergy in the model of sensitization used in this study. We report that the genetic background does not influence the consequence of this depletion regimen. These results signify the temporal regulation exerted by Foxp3+ Tregs in limiting allergic airway inflammation and may influence their application as potential therapeutics. 相似文献
999.
Virginie Le Brun Wolfgang Friess Torsten Schultz-Fademrecht Silke Muehlau Patrick Garidel Dr. 《Biotechnology journal》2009,4(9):1305-1319
The purpose of the presented study is to understand the physicochemical properties of proteins in aqueous solutions in order to identify solution conditions with reduced attractive protein-protein interactions, to avoid the formation of protein aggregates and to increase protein solubility. This is assessed by measuring the osmotic second virial coefficient (B22), a parameter of solution non-ideality, which is obtained using self-interaction chromatography. The model protein is lysozyme. The influence of various solution conditions on B22 was investigated: protonation degree, ionic strength, pharmaceutical relevant excipients and combinations thereof. Under acidic solution conditions B22 is positive, favoring protein repulsion. A similar trend is observed for the variation of the NaCl concentration, showing that with increasing the ionic strength protein attraction is more likely. B22 decreases and becomes negative. Thus, solution conditions are obtained favoring attractive protein-protein interactions. The B22 parameter also reflects, in general, the influence of the salts of the Hofmeister series with regard to their salting-in/salting-out effect. It is also shown that B22 correlates with protein solubility as well as physical protein stability. 相似文献
1000.
Stefanie Graewe Silke Retzlaff Nicole Struck Chris J. Janse Volker T. Heussler Dr. 《Biotechnology journal》2009,4(6):895-902
Fluorescent proteins have proven to be important tools for in vitro live imaging of parasites and for imaging of parasites within the living host by intravital microscopy. We observed that a red fluorescent transgenic malaria parasite of rodents, Plasmodium berghei-RedStar, is suitable for in vitro live imaging experiments but bleaches rapidly upon illumination in intravital imaging experiments using mice. We have therefore generated two additional transgenic parasite lines expressing the novel red fluorescent proteins tdTomato and mCherry, which have been reported to be much more photostable than first- and second-generation red fluorescent proteins including RedStar. We have compared all three red fluorescent parasite lines for their use in in vitro live and intravital imaging of P. berghei blood and liver parasite stages, using both confocal and wide-field microscopy. While tdTomato bleached almost as rapidly as RedStar, mCherry showed improved photostability and was bright in all experiments performed. 相似文献