TY - JOUR A1 - Jakob, Franz A1 - Ebert, Regina A1 - Rudert, Maximilian A1 - Nöth, Ulrich A1 - Walles, Heike A1 - Docheva, Denitsa A1 - Schieker, Matthias A1 - Meinel, Lorenz A1 - Groll, Jürgen T1 - In situ guided tissue regeneration in musculoskeletal diseases and aging JF - Cell and Tissue Research N2 - In situ guided tissue regeneration, also addressed as in situ tissue engineering or endogenous regeneration, has a great potential for population-wide “minimal invasive” applications. During the last two decades, tissue engineering has been developed with remarkable in vitro and preclinical success but still the number of applications in clinical routine is extremely small. Moreover, the vision of population-wide applications of ex vivo tissue engineered constructs based on cells, growth and differentiation factors and scaffolds, must probably be deemed unrealistic for economic and regulation-related issues. Hence, the progress made in this respect will be mostly applicable to a fraction of post-traumatic or post-surgery situations such as big tissue defects due to tumor manifestation. Minimally invasive procedures would probably qualify for a broader application and ideally would only require off the shelf standardized products without cells. Such products should mimic the microenvironment of regenerating tissues and make use of the endogenous tissue regeneration capacities. Functionally, the chemotaxis of regenerative cells, their amplification as a transient amplifying pool and their concerted differentiation and remodeling should be addressed. This is especially important because the main target populations for such applications are the elderly and diseased. The quality of regenerative cells is impaired in such organisms and high levels of inhibitors also interfere with regeneration and healing. In metabolic bone diseases like osteoporosis, it is already known that antagonists for inhibitors such as activin and sclerostin enhance bone formation. Implementing such strategies into applications for in situ guided tissue regeneration should greatly enhance the efficacy of tailored procedures in the future. KW - in situ guided tissue regeneration KW - stem cells KW - scaffolds KW - regenerative medicine KW - mesenchymal tissues Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-124738 VL - 347 IS - 3 ER - TY - JOUR A1 - Ebert, Regina A1 - Weissenberger, Manuel A1 - Braun, Clemens A1 - Wagenbrenner, Mike A1 - Herrmann, Marietta A1 - Müller‐Deubert, Sigrid A1 - Krug, Melanie A1 - Jakob, Franz A1 - Rudert, Maximilian T1 - Impaired regenerative capacity and senescence‐associated secretory phenotype in mesenchymal stromal cells from samples of patients with aseptic joint arthroplasty loosening JF - Journal of Orthopaedic Research N2 - Aseptic loosening of total hip and knee joint replacements is the most common indication for revision surgery after primary hip and knee arthroplasty. Research suggests that exposure and uptake of wear by mesenchymal stromal cells (MSC) and macrophages results in the secretion of proinflammatory cytokines and local osteolysis, but also impaired cell viability and regenerative capacity of MSC. Therefore, this in vitro study compared the regenerative and differentiation capacity of MSC derived from patients undergoing primary total hip arthroplasty (MSCprim) to MSC derived from patients undergoing revision surgery after aseptic loosening of total hip and knee joint implants (MSCrev). Regenerative capacity was examined by measuring the cumulative population doubling (CPD) in addition to the number of passages until cells stopped proliferating. Osteogenesis and adipogenesis in monolayer cultures were assessed using histological stainings. Furthermore, RT‐PCR was performed to evaluate the relative expression of osteogenic and adipogenic marker genes as well as the expression of markers for a senescence‐associated secretory phenotype (SASP). MSCrev possessed a limited regenerative capacity in comparison to MSCprim. Interestingly, MSCrev also showed an impaired osteogenic and adipogenic differentiation capacity compared to MSCprim and displayed a SASP early after isolation. Whether this is the cause or the consequence of the aseptic loosening of total joint implants remains unclear. Future research should focus on the identification of specific cell markers on MSCprim, which may influence complication rates such as aseptic loosening of total joint arthroplasty to further individualize and optimize total joint arthroplasty. KW - aseptic loosening KW - mesenchymal stromal cells KW - regenerative capacity KW - senescence‐associated secretory phenotype Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-238963 VL - 40 IS - 2 SP - 513 EP - 523 ER - TY - JOUR A1 - Altmann, Stephan A1 - Mut, Jürgen A1 - Wolf, Natalia A1 - Meißner-Weigl, Jutta A1 - Rudert, Maximilian A1 - Jakob, Franz A1 - Gutmann, Marcus A1 - Lühmann, Tessa A1 - Seibel, Jürgen A1 - Ebert, Regina T1 - Metabolic glycoengineering in hMSC-TERT as a model for skeletal precursors by using modified azide/alkyne monosaccharides JF - International Journal of Molecular Sciences N2 - Metabolic glycoengineering enables a directed modification of cell surfaces by introducing target molecules to surface proteins displaying new features. Biochemical pathways involving glycans differ in dependence on the cell type; therefore, this technique should be tailored for the best results. We characterized metabolic glycoengineering in telomerase-immortalized human mesenchymal stromal cells (hMSC-TERT) as a model for primary hMSC, to investigate its applicability in TERT-modified cell lines. The metabolic incorporation of N-azidoacetylmannosamine (Ac\(_4\)ManNAz) and N-alkyneacetylmannosamine (Ac\(_4\)ManNAl) into the glycocalyx as a first step in the glycoengineering process revealed no adverse effects on cell viability or gene expression, and the in vitro multipotency (osteogenic and adipogenic differentiation potential) was maintained under these adapted culture conditions. In the second step, glycoengineered cells were modified with fluorescent dyes using Cu-mediated click chemistry. In these analyses, the two mannose derivatives showed superior incorporation efficiencies compared to glucose and galactose isomers. In time-dependent experiments, the incorporation of Ac\(_4\)ManNAz was detectable for up to six days while Ac\(_4\)ManNAl-derived metabolites were absent after two days. Taken together, these findings demonstrate the successful metabolic glycoengineering of immortalized hMSC resulting in transient cell surface modifications, and thus present a useful model to address different scientific questions regarding glycosylation processes in skeletal precursors. KW - hMSC-TERT KW - metabolic glycoengineering KW - glycocalyx KW - modified monosaccharides KW - click chemistry Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-259247 SN - 1422-0067 VL - 22 IS - 6 ER - TY - JOUR A1 - Herrmann, Marietta A1 - Engelke, Klaus A1 - Ebert, Regina A1 - Müller-Deubert, Sigrid A1 - Rudert, Maximilian A1 - Ziouti, Fani A1 - Jundt, Franziska A1 - Felsenberg, Dieter A1 - Jakob, Franz T1 - Interactions between muscle and bone — Where physics meets biology JF - Biomolecules N2 - Muscle and bone interact via physical forces and secreted osteokines and myokines. Physical forces are generated through gravity, locomotion, exercise, and external devices. Cells sense mechanical strain via adhesion molecules and translate it into biochemical responses, modulating the basic mechanisms of cellular biology such as lineage commitment, tissue formation, and maturation. This may result in the initiation of bone formation, muscle hypertrophy, and the enhanced production of extracellular matrix constituents, adhesion molecules, and cytoskeletal elements. Bone and muscle mass, resistance to strain, and the stiffness of matrix, cells, and tissues are enhanced, influencing fracture resistance and muscle power. This propagates a dynamic and continuous reciprocity of physicochemical interaction. Secreted growth and differentiation factors are important effectors of mutual interaction. The acute effects of exercise induce the secretion of exosomes with cargo molecules that are capable of mediating the endocrine effects between muscle, bone, and the organism. Long-term changes induce adaptations of the respective tissue secretome that maintain adequate homeostatic conditions. Lessons from unloading, microgravity, and disuse teach us that gratuitous tissue is removed or reorganized while immobility and inflammation trigger muscle and bone marrow fatty infiltration and propagate degenerative diseases such as sarcopenia and osteoporosis. Ongoing research will certainly find new therapeutic targets for prevention and treatment. KW - muscle KW - bone KW - mechanosensing KW - mechanotransduction KW - myokines KW - osteokines adaptation Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-203399 SN - 2218-273X VL - 10 IS - 3 ER - TY - JOUR A1 - Wagenbrenner, Mike A1 - Poker, Konrad A1 - Heinz, Tizian A1 - Herrmann, Marietta A1 - Horas, Konstantin A1 - Ebert, Regina A1 - Mayer-Wagner, Susanne A1 - Holzapfel, Boris M. A1 - Rudert, Maximilian A1 - Steinert, Andre F. A1 - Weißenberger, Manuel T1 - Mesenchymal stromal cells (MSCs) isolated from various tissues of the human arthritic knee joint possess similar multipotent differentiation potential JF - Applied Sciences N2 - (1) Background: The mesenchymal stromal cells (MSCs) of different tissue origins are applied in cell-based chondrogenic regeneration. However, there is a lack of comparability determining the most suitable cell source for the tissue engineering (TE) of cartilage. The purpose of this study was to compare the in vitro chondrogenic potential of MSC-like cells from different tissue sources (bone marrow, meniscus, anterior cruciate ligament, synovial membrane, and the infrapatellar fat pad removed during total knee arthroplasty (TKA)) and define which cell source is best suited for cartilage regeneration. (2) Methods: MSC-like cells were isolated from five donors and expanded using adherent monolayer cultures. Differentiation was induced by culture media containing specific growth factors. Transforming growth factor (TGF)-ß1 was used as the growth factor for chondrogenic differentiation. Osteogenesis and adipogenesis were induced in monolayer cultures for 27 days, while pellet cell cultures were used for chondrogenesis for 21 days. Control cultures were maintained under the same conditions. After, the differentiation period samples were analyzed, using histological and immunohistochemical staining, as well as molecularbiological analysis by RT-PCR, to assess the expression of specific marker genes. (3) Results: Plastic-adherent growth and in vitro trilineage differentiation capacity of all isolated cells were proven. Flow cytometry revealed the clear co-expression of surface markers CD44, CD73, CD90, and CD105 on all isolated cells. Adipogenesis was validated through the formation of lipid droplets, while osteogenesis was proven by the formation of calcium deposits within differentiated cell cultures. The formation of proteoglycans was observed during chondrogenesis in pellet cultures, with immunohistochemical staining revealing an increased relative gene expression of collagen type II. RT-PCR proved an elevated expression of specific marker genes after successful differentiation, with no significant differences regarding different cell source of native tissue. (4) Conclusions: Irrespective of the cell source of native tissue, all MSC-like cells showed multipotent differentiation potential in vitro. The multipotent differentiation capacity did not differ significantly, and chondrogenic differentiation was proven in all pellet cultures. Therefore, cell suitability for cell-based cartilage therapies and tissue engineering is given for various tissue origins that are routinely removed during total knee arthroplasty (TKA). This study might provide essential information for the clinical tool of cell harvesting, leading to more flexibility in cell availability. KW - knee joint KW - MSCs KW - cellular origin KW - cartilage regeneration KW - tissue engineering KW - cell-based therapies KW - osteoarthritis Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-262334 SN - 2076-3417 VL - 12 IS - 4 ER - TY - JOUR A1 - Seiler, Jonas A1 - Ebert, Regina A1 - Rudert, Maximilian A1 - Herrmann, Marietta A1 - Leich, Ellen A1 - Weißenberger, Manuela A1 - Horas, Konstantin T1 - Bone metastases of diverse primary origin frequently express the VDR (vitamin D receptor) and CYP24A1 JF - Journal of Clinical Medicine N2 - Active vitamin D (1,25(OH)2D3) is known to exert direct anti-cancer actions on various malignant tissues through binding to the vitamin D receptor (VDR). These effects have been demonstrated in breast, prostate, renal and thyroid cancers, which all have a high propensity to metastasise to bone. In addition, there is evidence that vitamin D catabolism via 24-hydroxylase (CYP24A1) is altered in tumour cells, thus, reducing local active vitamin D levels in cancer cells. The aim of this study was to assess VDR and CYP24A1 expression in various types of bone metastases by using immunohistochemistry. Overall, a high total VDR protein expression was detected in 59% of cases (39/66). There was a non-significant trend of high-grade tumours towards the low nuclear VDR expression (p = 0.07). Notably, patients with further distant metastases had a reduced nuclear VDR expression (p = 0.03). Furthermore, a high CYP24A1 expression was detected in 59% (39/66) of bone metastases. There was a significant positive correlation between nuclear VDR and CYP24A1 expression (p = 0.001). Collectively, the VDR and CYP24A1 were widely expressed in a multitude of bone metastases, pointing to a potential role of vitamin D signalling in cancer progression. This is of high clinical relevance, as vitamin D deficiency is frequent in patients with bone metastases. KW - vitamin D receptor KW - VDR KW - CYP24A1 KW - bone metastasis KW - vitamin D Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-297377 SN - 2077-0383 VL - 11 IS - 21 ER -