@article{GereckeMascherGottschalketal.2013, author = {Gerecke, Christian and Mascher, Conny and Gottschalk, Uwe and Kleuser, Burkhard and Scholtka, Bettina}, title = {Ultrasensitive detection of unknown colon cancer-initiating mutations using the example of the adenomatous polyposis coli gene}, series = {Cancer prevention research}, volume = {6}, journal = {Cancer prevention research}, number = {9}, publisher = {American Association for Cancer Research}, address = {Philadelphia}, issn = {1940-6207}, doi = {10.1158/1940-6207.CAPR-13-0145}, pages = {898 -- 907}, year = {2013}, abstract = {Detection of cancer precursors contributes to cancer prevention, for example, in the case of colorectal cancer. To record more patients early, ultrasensitive methods are required for the purpose of noninvasive precursor detection in body fluids. Our aim was to develop a method for enrichment and detection of known as well as unknown driver mutations in the Adenomatous polyposis coli (APC) gene. By coupled wild-type blocking (WTB) PCR and high-resolution melting (HRM), referred to as WTB-HRM, a minimum detection limit of 0.01\% mutant in excess wild-type was achieved according to as little as 1 pg mutated DNA in the assay. The technique was applied to 80 tissue samples from patients with colorectal cancer (n = 17), adenomas (n = 50), serrated lesions (n = 8), and normal mucosa (n = 5). Any kind of known and unknown APC mutations (deletions, insertions, and base exchanges) being situated inside the mutation cluster region was distinguishable from wild-type DNA. Furthermore, by WTB-HRM, nearly twice as many carcinomas and 1.5 times more precursor lesions were identified to be mutated in APC, as compared with direct sequencing. By analyzing 31 associated stool DNA specimens all but one of the APC mutations could be recovered. Transferability of the WTB-HRM method to other genes was proven using the example of KRAS mutation analysis. In summary, WTB-HRM is a new approach for ultrasensitive detection of cancer-initiating mutations. In this sense, it appears especially applicable for noninvasive detection of colon cancer precursors in body fluids with excess wild-type DNA like stool. Cancer Prev Res; 6(9); 898-907. (C) 2013 AACR.}, language = {en} } @article{SchaperDickhautJaptoketal.2013, author = {Schaper, Katrin and Dickhaut, Jeannette and Japtok, Lukasz and Kietzmann, Manfred and Mischke, Reinhard and Kleuser, Burkhard and B{\"a}umer, Wolfgang}, title = {Sphingosine-1-phosphate exhibits anti-proliferative and anti-inflammatory effects in mouse models of psoriasis}, series = {Journal of dermatological scienc}, volume = {71}, journal = {Journal of dermatological scienc}, number = {1}, publisher = {Elsevier}, address = {Clare}, issn = {0923-1811}, doi = {10.1016/j.jdermsci.2013.03.006}, pages = {29 -- 36}, year = {2013}, abstract = {Background: It has been indicated that the sphingolipid sphingosine-1-phosphate (SIP) restrains the ability of dendritic cells to migrate to lymph nodes. Furthermore SIP has been demonstrated to inhibit cell growth in human keratinocytes. However, only little is known about the effect of S1P in hyperproliferative and inflammatory in vivo models. Objective: In this study, locally acting SIP was explored in different experimental mouse models of psoriasis vulgaris. Methods: S1P and FTY720 were tested in the imiquimod-induced psoriasis mouse model, the mouse tail assay and a pilot study of the severe combined immunodeficiency mice (SCID). Results: In the imiquimod model the positive control diflorasone diacetate and S1P, but not FTY720 reduced the imiquimod-induced epidermal hyperproliferation of the ear skin. This effect was confirmed in the SCID model, where S1P treated skin from patients suffering from psoriasis showed a decrease in epidermal thickness compared to vehicle. In the imiquimod model, there was also significant inhibition of ear swelling and a moderate reduction of inflammatory cell influx and oedema formation in ear skin by SIP treatment. The inflammatory response on the back skin was, however, only reduced by diflorasone diacetate. In the mouse tail assay, the influence of S1P and FTY720 in stratum granulosum formation was tested compared to the positive control calcipotriol. Whereas topical administration of calcipotriol led to a low but significant increase of stratum granulosum, S1P and FTY720 lacked such an effect. Conclusion: Taken together, these results imply that topical administration of SIP might be a new option for the treatment of mild to moderate psoriasis lesions.}, language = {en} } @article{LotinunKivirantaMatsubaraetal.2013, author = {Lotinun, Sutada and Kiviranta, Riku and Matsubara, Takuma and Alzate, Jorge A. and Neff, Lynn and L{\"u}th, Anja and Koskivirta, Ilpo and Kleuser, Burkhard and Vacher, Jean and Vuorio, Eero and Horne, William C. and Baron, Roland}, title = {Osteoclast-specific cathepsin K deletion stimulates S1P-dependent bone formation}, series = {The journal of clinical investigation}, volume = {123}, journal = {The journal of clinical investigation}, number = {2}, publisher = {American Society for Clinical Investigation}, address = {Ann Arbor}, issn = {0021-9738}, doi = {10.1172/JCI64840}, pages = {666 -- 681}, year = {2013}, abstract = {Cathepsin K (CTSK) is secreted by osteoclasts to degrade collagen and other matrix proteins during bone resorption. Global deletion of Ctsk in mice decreases bone resorption, leading to osteopetrosis, but also increases the bone formation rate (BFR). To understand how Ctsk deletion increases the BFR, we generated osteoclast- and osteoblast-targeted Ctsk knockout mice using floxed Ctsk alleles. Targeted ablation of Ctsk in hematopoietic cells, or specifically in osteoclasts and cells of the monocyte-osteoclast lineage, resulted in increased bone volume and BFR as well as osteoclast and osteoblast numbers. In contrast, targeted deletion of Ctsk in osteoblasts had no effect on bone resorption or BFR, demonstrating that the increased BFR is osteoclast dependent. Deletion of Ctsk in osteoclasts increased their sphingosine kinase 1 (Sphk1) expression. Conditioned media from Ctsk-deficient osteoclasts, which contained elevated levels of sphingosine-l-phosphate (S1P), increased alkaline phosphatase and mineralized nodules in osteoblast cultures. An S1P(1,3) receptor antagonist inhibited these responses. Osteoblasts derived from mice with Ctsk-deficient osteoclasts had an increased RANKL/OPG ratio, providing a positive feedback loop that increased the number of osteoclasts. Our data provide genetic evidence that deletion of CTSK in osteoclasts enhances bone formation in vivo by increasing the generation of osteoclast-derived S1P.}, language = {en} } @article{BoehmFloesserErmleretal.2013, author = {B{\"o}hm, Andreas and Fl{\"o}ßer, Anja and Ermler, Swen and Fender, Anke C. and L{\"u}th, Anja and Kleuser, Burkhard and Schr{\"o}r, Karsten and Rauch, Bernhard H.}, title = {Factor-Xa-induced mitogenesis and migration require sphingosine kinase activity and S1P formation in human vascular smooth muscle cells}, series = {Cardiovascular research}, volume = {99}, journal = {Cardiovascular research}, number = {3}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0008-6363}, doi = {10.1093/cvr/cvt112}, pages = {505 -- 513}, year = {2013}, abstract = {Sphingosine-1-phosphate (S1P) is a cellular signalling lipid generated by sphingosine kinase-1 (SPHK1). The aim of the study was to investigate whether the activated coagulation factor-X (FXa) regulates SPHK1 transcription and the formation of S1P and subsequent mitogenesis and migration of human vascular smooth muscle cells (SMC). FXa induced a time- (36 h) and concentration-dependent (330 nmol/L) increase of SPHK1 mRNA and protein expression in human aortic SMC, resulting in an increased synthesis of S1P. FXa-stimulated transcription of SPHK1 was mediated by the protease-activated receptor-1 (PAR-1) and PAR-2. In human carotid artery plaques, expression of SPHK1 was observed at SMC-rich sites and was co-localized with intraplaque FX/FXa content. FXa-induced SPHK1 transcription was attenuated by inhibitors of Rho kinase (Y27632) and by protein kinase C (PKC) isoforms (GF109203X). In addition, FXa rapidly induced the activation of the small GTPase Rho A. Inhibition of signalling pathways which regulate SPHK1 expression, inhibition of its activity or siRNA-mediated SPHK1 knockdown attenuated the mitogenic and chemotactic response of human SMC to FXa. These data suggest that FXa induces SPHK1 expression and increases S1P formation independent of thrombin and that this involves the activation of Rho A and PKC signalling. In addition to its key function in coagulation, this direct effect of FXa on human SMC may increase cell proliferation and migration at sites of vessel injury and thereby contribute to the progression of vascular lesions.}, language = {en} } @misc{PolzinRassafBoehmetal.2013, author = {Polzin, Amin and Rassaf, Tienush and Boehm, Andreas and Lueth, Anja and Kleuser, Burkhard and Zeus, Tobias and Kelm, Malte and Kroemer, Heyo K. and Schroer, Karsten and Rauch, Bernhard H.}, title = {Aspirin inhibits release of platelet-derived sphingosine-1-phosphate in acute myocardial infarction}, series = {INTERNATIONAL JOURNAL OF CARDIOLOGY}, volume = {170}, journal = {INTERNATIONAL JOURNAL OF CARDIOLOGY}, number = {2}, publisher = {ELSEVIER IRELAND LTD}, address = {CLARE}, issn = {0167-5273}, doi = {10.1016/j.ijcard.2013.10.050}, pages = {E23 -- E24}, year = {2013}, language = {en} }