Pozivamo Vas na 27. Fakultetski seminar Prirodoslovno-matematičkog fakulteta, koji će se održati u srijedu 3. listopada 2018. godine u 13:00 sati u amfiteatru A1-1 na kojem će Prof. Dr. Stefan Kalkhof sa Sveučilišta za primijenjene znanosti iz Coburga u Njemačkoj, održati predavanje:
Guiding bone implant development by protein mass spectrometric analyses
Stefan Kalkhof1,2,3
1 Institute of Bioanalysis, University of Applied Sciences of Coburg, Germany
2 Department for Molecular Systems Biology, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany
3 Department Therapy Validation, Fraunhofer Institute for Cell Therapy and Immunology – IZI, Leipzig, Germany
New implant materials, which support and accelerate active healing, are of high interest to deal with age-related diseases responsible for impaired bone healing. One promising therapeutic approach involves the coating of implants with modified glycosaminoglycans (GAGs) that partially mimic the native bone environment and actively promote osteogenesis and bone remodeling. During the last years we developed and applied mass spectrometry based methods to study toxicological, mechanistic, and structural aspects of cell-implant and protein-implant interactions. Initially we studied the effect of several chemically modified GAGs on bone resorbing osteoclast as well as on bone forming osteoblast in vitro (1). To unravel the mechanism of increased bone formation in more detail we investigated whether GAGs influence only osteoblasts or whether they also directly affect the formation, composition, activity, and distribution of osteoblast-released matrix vesicles (MV). Thus, MVs were enriched and the MV proteome as well as the proteome of the MV-releasing osteoblasts was analyzed with and without contact to sulfated GAGs (2). The question whether and how selected proteins can be enriched or effected due to specific chemical modifications of the GAGs and which interaction sites were involved, was addressed using H/D exchange mass spectrometry (3,4). Finally for the evaluation of the immune reaction of animals to diverse implants, wound-fluid samples were collected by microdialysis and quantified by mass spectrometry. This approach allows us to assess bone specific cytokine responses and distinct protein and metabolite profiles at several time points during the first 24 h of wound healing (5,6).
1- Sulfated hyaluronan containing collagen matrices enhance cell-matrix-interaction, endocytosis, and osteogenic differentiation of human mesenchymal stromal cells. Kliemt S, Lange C, Otto W, Hintze V, Möller S, von Bergen M, Hempel U, Kalkhof S.
J Proteome Res. 2013
2- Osteoblast-released Matrix Vesicles, Regulation of Activity and Composition by Sulfated and Non-sulfated Glycosaminoglycans. Schmidt JR, Kliemt S, Preissler C, Moeller S, von Bergen M, Hempel U, Kalkhof S. Mol Cell Proteomics. 2016 Feb;15(2):558-72
3- Structural analysis of the interleukin-8/glycosaminoglycan interactions by amide hydrogen/deuterium exchange mass spectrometry.Hofmann T, Samsonov SA, Pichert A, Lemmnitzer K, Schiller J, Huster D, Pisabarro MT, von Bergen M, Kalkhof S. Methods. 2015 Nov 1;89:45-53
4- Structural and functional insights into the interaction of sulfated glycosaminoglycans with tissue inhibitor of metalloproteinase-3 – A possible regulatory role on extracellular matrix homeostasis. Rother S, Samsonov SA, Hofmann T, Blaszkiewicz J, Köhling S, Moeller S, Schnabelrauch M, Rademann J, Kalkhof S, von Bergen M, Pisabarro MT, Scharnweber D, Hintze V. Acta Biomater. 2016 Nov; 45:143-154.
5- Proteomics and metabolomics for in situ monitoring of wound healing. Kalkhof S, Förster Y, Schmidt J, Schulz MC, Baumann S, Weißflog A, Gao W, Hempel U, Eckelt U, Rammelt S, von Bergen M. Biomed Res Int. 2014;2014:934848
6- Microdialysis Sampling from Wound Fluids Enables Quantitative Assessment of Cytokines, Proteins, and Metabolites Reveals Bone Defect-Specific Molecular Profiles. Förster Y, Schmidt JR, Wissenbach DK, Pfeiffer SE, Baumann S, Hofbauer LC, von Bergen M, Kalkhof S, Rammelt S. PLoS One. 2016 Jul 21;11(7):e0159580