TY - JOUR A1 - Regn, Michael A1 - Laggerbauer, Bernhard A1 - Jentzsch, Claudia A1 - Ramanujam, Deepak A1 - Ahles, Andrea A1 - Sichler, Sonja A1 - Calzada-Wack, Julia A1 - Koenen, Rory R. A1 - Braun, Attila A1 - Nieswandt, Bernhard A1 - Engelhardt, Stefan T1 - Peptidase inhibitor 16 is a membrane-tethered regulator of chemerin processing in the myocardium JF - Journal of Molecular and Cellular Cardiology N2 - A key response of the myocardium to stress is the secretion of factors with paracrine or endocrine function. Intriguing in this respect is peptidase inhibitor 16 (PI16), a member of the CAP family of proteins which we found to be highly upregulated in cardiac disease. Up to this point, the mechanism of action and physiological function of PI16 remained elusive. Here, we show that PI16 is predominantly expressed by cardiac fibroblasts, which expose PI16 to the interstitium via a glycophosphatidylinositol (-GPI) membrane anchor. Based on a reported genetic association of PI16 and plasma levels of the chemokine chemerin, we investigated whether PI16 regulates post-translational processing of its precursor pro-chemerin. PI16-deficient mice were engineered and found to generate higher levels of processed chemerin than wildtype mice. Purified recombinant PI16 efficiently inhibited cathepsin K, a chemerin-activating protease, in vitro. Moreover, we show that conditioned medium from PI16-overexpressing cells impaired the activation of pro-chemerin. Together, our data indicate that PI16 suppresses chemerin activation in the myocardium and suggest that this circuit may be part of the cardiac stress response. KW - Cells KW - Activation KW - Purification KW - Protein KW - Peptidase inhibitor 16 (PI16) KW - Identification KW - Inflammation KW - Adipokine KW - Metabolism KW - Heart KW - Mice KW - Chemerin KW - RARRES2 KW - TIG2 KW - Protease inhibition KW - Chemerin processing Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-187039 VL - 99 ER - TY - JOUR A1 - Gilder, Stuart A. A1 - Wack, Michael A1 - Kaub, Leon A1 - Roud, Sophie C. A1 - Petersen, Nikolai A1 - Heinsen, Helmut A1 - Hillenbrand, Peter A1 - Milz, Stefan A1 - Schmitz, Chistoph T1 - Distribution of magnetic remanence carriers in the human brain JF - Scientific Reports N2 - That the human brain contains magnetite is well established; however, its spatial distribution in the brain has remained unknown. We present room temperature, remanent magnetization measurements on 822 specimens from seven dissected whole human brains in order to systematically map concentrations of magnetic remanence carriers. Median saturation remanent magnetizations from the cerebellum were approximately twice as high as those from the cerebral cortex in all seven cases (statistically significantly distinct, pā€‰=ā€‰0.016). Brain stems were over two times higher in magnetization on average than the cerebral cortex. The ventral (lowermost) horizontal layer of the cerebral cortex was consistently more magnetic than the average cerebral cortex in each of the seven studied cases. Although exceptions existed, the reproducible magnetization patterns lead us to conclude that magnetite is preferentially partitioned in the human brain, specifically in the cerebellum and brain stem. KW - brain KW - neurophysiology Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-233035 VL - 8 ER -