TY - JOUR A1 - Zirafi, Onofrio A1 - Kim, Kyeong-Ae A1 - Ständker, Ludger A1 - Mohr, Katharina B. A1 - Sauter, Daniel A1 - Heigele, Anke A1 - Kluge, Silvia F. A1 - Wiercinska, Eliza A1 - Chudziak, Doreen A1 - Richter, Rudolf A1 - Möpps, Barbara A1 - Gierschik, Peter A1 - Vas, Virag A1 - Geiger, Hartmut A1 - Lamla, Markus A1 - Weil, Tanja A1 - Burster, Timo A1 - Zgraja, Andreas A1 - Daubeuf, Francois A1 - Frossard, Nelly A1 - Hachet-Haas, Muriel A1 - Heunisch, Fabian A1 - Reichetzeder, Christoph A1 - Galzi, Jean-Luc A1 - Perez-Castells, Javier A1 - Canales-Mayordomo, Angeles A1 - Jimenez-Barbero, Jesus A1 - Gimenez-Gallego, Guillermo A1 - Schneider, Marion A1 - Shorter, James A1 - Telenti, Amalio A1 - Hocher, Berthold A1 - Forssmann, Wolf-Georg A1 - Bonig, Halvard A1 - Kirchhoff, Frank A1 - Münch, Jan T1 - Discovery and Characterization of an Endogenous CXCR4 Antagonist JF - Cell reports N2 - CXCL12-CXCR4 signaling controls multiple physiological processes and its dysregulation is associated with cancers and inflammatory diseases. To discover as-yet-unknown endogenous ligands of CXCR4, we screened a blood-derived peptide library for inhibitors of CXCR4-tropic HIV-1 strains. This approach identified a 16 amino acid fragment of serum albumin as an effective and highly specific CXCR4 antagonist. The endogenous peptide, termed EPI-X4, is evolutionarily conserved and generated from the highly abundant albumin precursor by pH-regulated proteases. EPI-X4 forms an unusual lasso-like structure and antagonizes CXCL12-induced tumor cell migration, mobilizes stem cells, and suppresses inflammatory responses in mice. Furthermore, the peptide is abundant in the urine of patients with inflammatory kidney diseases and may serve as a biomarker. Our results identify EPI-X4 as a key regulator of CXCR4 signaling and introduce proteolysis of an abundant precursor protein as an alternative concept for chemokine receptor regulation. Y1 - 2015 U6 - https://doi.org/10.1016/j.celrep.2015.03.061 SN - 2211-1247 VL - 11 IS - 5 SP - 737 EP - 747 PB - Cell Press CY - Cambridge ER - TY - JOUR A1 - Dschietzig, Thomas Bernd A1 - Krause-Relle, Katharina A1 - Hennequin, Maud A1 - von Websky, Karoline A1 - Rahnenfuhrer, Jan A1 - Ruppert, Jana A1 - Groena, Hans Juergen A1 - Armbruster, Franz Paul A1 - Bathgate, Ross A. D. A1 - Aschenbach, Joerg R. A1 - Forssmann, Wolf-Georg A1 - Hocher, Berthold T1 - Relaxin-2 does not Ameliorate Nephropathy in an experimental model of Type-1 Diabetes JF - Kidney & blood pressure research : official organ of the Gesellschaft für Nephrologie N2 - Background/Aims: In diabetic nephropathy (DN), the current angiotensin-II-blocking pharmacotherapy is frequently failing. For diabetic cardiomyopathy (DC), there is no specific remedy available. Relaxin-2 (Rlx) - an anti-fibrotic, anti-inflammatory, and vasoprotecting peptide - is a candidate drug for both. Methods: Low-dose (32 mu g/kg/day) and high-dose (320 mu g/kg/day) Rlx were tested against vehicle (n = 20 each) and non-diabetic controls (n = 14) for 12 weeks in a model of type-1 diabetes induced in endothelial nitric oxide synthase knock-out (eNOS-KO) mice by intraperitoneal injection of streptozotocin. Results: Diabetic animals showed normal plasma creatinine, markedly increased albuminuria and urinary malonyldialdehyde, elevated relative kidney weight, glomerulosclerosis, and increased glomerular size, but no relevant interstitial fibrosis. Neither dose of Rlx affected these changes although the drug was active and targeted plasma levels were achieved. Of note, we found no activation of the renal TGF-beta pathway in this model. In the hearts of diabetic animals, no fibrotic alterations indicative of DC could be determined which precluded testing of the initial hypothesis. Conclusions: We investigated a model showing early DN without overt tubulo-interstitial fibrosis and activation of the TGF-beta-Smad-2/3 pathway. In this model, Rlx proved ineffective; however, the same may not apply to other models and types of diabetes. KW - Diabetic nephropathy KW - Diabetic cardiomyopathy KW - Fibrosis KW - Inflammation KW - Relaxin Y1 - 2015 U6 - https://doi.org/10.1159/000368484 SN - 1420-4096 SN - 1423-0143 VL - 40 IS - 1 SP - 77 EP - 88 PB - Karger CY - Basel ER -