@article{BenischSchillingKleinHitpassetal.2012, author = {Benisch, Peggy and Schilling, Tatjana and Klein-Hitpass, Ludger and Frey, S{\"o}nke P. and Seefried, Lothar and Raaijmakers, Nadja and Krug, Melanie and Regensburger, Martina and Zeck, Sabine and Schinke, Thorsten and Amling, Michael and Ebert, Amling and Jakob, Franz}, title = {The Transcriptional Profile of Mesenchymal Stem Cell Populations in Primary Osteoporosis Is Distinct and Shows Overexpression of Osteogenic Inhibitors}, series = {PLoS One}, volume = {7}, journal = {PLoS One}, number = {9}, doi = {10.1371/journal.pone.0045142}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-133379}, pages = {e45142}, year = {2012}, abstract = {Primary osteoporosis is an age-related disease characterized by an imbalance in bone homeostasis. While the resorptive aspect of the disease has been studied intensely, less is known about the anabolic part of the syndrome or presumptive deficiencies in bone regeneration. Multipotent mesenchymal stem cells (MSC) are the primary source of osteogenic regeneration. In the present study we aimed to unravel whether MSC biology is directly involved in the pathophysiology of the disease and therefore performed microarray analyses of hMSC of elderly patients (79-94 years old) suffering from osteoporosis (hMSC-OP). In comparison to age-matched controls we detected profound changes in the transcriptome in hMSC-OP, e.g. enhanced mRNA expression of known osteoporosis-associated genes (LRP5, RUNX2, COL1A1) and of genes involved in osteoclastogenesis (CSF1, PTH1R), but most notably of genes coding for inhibitors of WNT and BMP signaling, such as Sclerostin and MAB21L2. These candidate genes indicate intrinsic deficiencies in self-renewal and differentiation potential in osteoporotic stem cells. We also compared both hMSC-OP and non-osteoporotic hMSC-old of elderly donors to hMSC of similar to 30 years younger donors and found that the transcriptional changes acquired between the sixth and the ninth decade of life differed widely between osteoporotic and non-osteoporotic stem cells. In addition, we compared the osteoporotic transcriptome to long term-cultivated, senescent hMSC and detected some signs for pre-senescence in hMSC-OP. Our results suggest that in primary osteoporosis the transcriptomes of hMSC populations show distinct signatures and little overlap with non-osteoporotic aging, although we detected some hints for senescence-associated changes. While there are remarkable inter-individual variations as expected for polygenetic diseases, we could identify many susceptibility genes for osteoporosis known from genetic studies. We also found new candidates, e.g. MAB21L2, a novel repressor of BMP-induced transcription. Such transcriptional changes may reflect epigenetic changes, which are part of a specific osteoporosis-associated aging process.}, language = {en} } @article{KlotzMentrupRegensburgeretal.2012, author = {Klotz, Barbara and Mentrup, Birgit and Regensburger, Martina and Zeck, Sabine and Schneidereit, Jutta and Schupp, Nicole and Linden, Christian and Merz, Cornelia and Ebert, Regina and Jakob, Franz}, title = {1,25-Dihydroxyvitamin D3 Treatment Delays Cellular Aging in Human Mesenchymal Stem Cells while Maintaining Their Multipotent Capacity}, series = {PLoS ONE}, volume = {7}, journal = {PLoS ONE}, number = {1}, doi = {10.1371/journal.pone.0029959}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-133392}, pages = {e29959}, year = {2012}, abstract = {1,25-dihydroxyvitamin D3 (1,25D3) was reported to induce premature organismal aging in fibroblast growth factor-23 (Fgf23) and klotho deficient mice, which is of main interest as 1,25D3 supplementation of its precursor cholecalciferol is used in basic osteoporosis treatment. We wanted to know if 1,25D3 is able to modulate aging processes on a cellular level in human mesenchymal stem cells (hMSC). Effects of 100 nM 1,25D3 on hMSC were analyzed by cell proliferation and apoptosis assay, beta-galactosidase staining, VDR and surface marker immunocytochemistry, RT-PCR of 1,25D3-responsive, quiescence-and replicative senescence-associated genes. 1,25D3 treatment significantly inhibited hMSC proliferation and apoptosis after 72 h and delayed the development of replicative senescence in long-term cultures according to beta-galactosidase staining and P16 expression. Cell morphology changed from a fibroblast like appearance to broad and rounded shapes. Long term treatment did not induce lineage commitment in terms of osteogenic pathways but maintained their clonogenic capacity, their surface marker characteristics (expression of CD73, CD90, CD105) and their multipotency to develop towards the chondrogenic, adipogenic and osteogenic pathways. In conclusion, 1,25D3 delays replicative senescence in primary hMSC while the pro-aging effects seen in mouse models might mainly be due to elevated systemic phosphate levels, which propagate organismal aging.}, language = {en} } @article{RudertHolzapfelJakubietz2011, author = {Rudert, Maximilian and Holzapfel, Boris Michael and Jakubietz, Michael}, title = {Adjuvant Radiotherapy}, series = {Deutsches {\"A}rzteblatt International}, volume = {108}, journal = {Deutsches {\"A}rzteblatt International}, number = {33}, doi = {10.3238/arztebl.2011.0553a}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-133571}, pages = {553}, year = {2011}, abstract = {No abstract available.}, language = {en} } @article{HolzapfelChhayaMelchelsetal.2013, author = {Holzapfel, Boris Michael and Chhaya, Mohit Prashant and Melchels, Ferry Petrus Wilhelmus and Holzapfel, Nina Pauline and Prodinger, Peter Michael and von Eisenhart-Rothe, R{\"u}diger and Griensven, Martijn van and Schantz, Jan-Thorsten and Rudert, Maximilian and Hutmacher, Dietmar Werner}, title = {Can Bone Tissue Engineering Contribute to Therapy Concepts after Resection of Musculoskeletal Sarcoma?}, series = {Sarcoma}, volume = {2013}, journal = {Sarcoma}, number = {Article ID 153640}, doi = {10.1155/2013/153640}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-132465}, pages = {10 p.}, year = {2013}, abstract = {Resection of musculoskeletal sarcoma can result in large bone defects where regeneration is needed in a quantity far beyond the normal potential of self-healing. In many cases, these defects exhibit a limited intrinsic regenerative potential due to an adjuvant therapeutic regimen, seroma, or infection. Therefore, reconstruction of these defects is still one of the most demanding procedures in orthopaedic surgery. The constraints of common treatment strategies have triggered a need for new therapeutic concepts to design and engineer unparalleled structural and functioning bone grafts. To satisfy the need for long-term repair and good clinical outcome, a paradigm shift is needed from methods to replace tissues with inert medical devices to more biological approaches that focus on the repair and reconstruction of tissue structure and function. It is within this context that the field of bone tissue engineering can offer solutions to be implemented into surgical therapy concepts after resection of bone and soft tissue sarcoma. In this paper we will discuss the implementation of tissue engineering concepts into the clinical field of orthopaedic oncology.}, language = {en} } @article{WernerBoehmGohlke2013, author = {Werner, Birgit S. and Boehm, Dorota and Gohlke, Frank}, title = {Revision to reverse shoulder arthroplasty with retention of the humeral component Good outcome in 14 patients followed for a mean of 2.5 years}, series = {Acta Orthopaedica}, volume = {84}, journal = {Acta Orthopaedica}, number = {5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131621}, pages = {473-478}, year = {2013}, abstract = {Background: Revision in failed shoulder arthroplasty often requires removal of the humeral component with a significant risk of fracture and bone loss. Newer modular systems allow conversion from anatomic to reverse shoulder arthroplasty with retention of a well-fixed humeral stem. We report on a prospectively evaluated series of conversions from hemiarthroplasty to reverse shoulder arthroplasty. Methods: In 14 cases of failed hemiarthroplasty due to rotator cuff deficiency and painful pseudoparalysis (in 13 women), revision to reverse shoulder arthroplasty was performed between October 2006 and 2010, with retention of the humeral component using modular systems. Mean age at the time of operation was 70 (56-80) years. Pre- and postoperative evaluation followed a standardized protocol including Constant score, range of motion, and radiographic analysis. Mean follow-up time was 2.5 (2-5.5) years. Results: Mean Constant score improved from 9 (2-16) to 41 (17-74) points. Mean lengthening of the arm was 2.6 (0.9-4.7) cm without any neurological complications. One patient required revision due to infection. Interpretation Modular systems allow retainment of a well-fixed humeral stem with good outcome. There is a risk of excessive humeral lengthening.}, language = {en} } @article{LiedertRoentgenSchinkeetal.2014, author = {Liedert, Astrid and R{\"o}ntgen, Viktoria and Schinke, Thorsten and Benisch, Peggy and Ebert, Regina and Jakob, Franz and Klein-Hitpass, Ludger and Lennerz, Jochen K. and Amling, Michael and Ignatius, Anita}, title = {Osteoblast-Specific Krm2 Overexpression and Lrp5 Deficiency Have Different Effects on Fracture Healing in Mice}, series = {PLOS ONE}, volume = {9}, journal = {PLOS ONE}, number = {7}, issn = {1932-6203}, doi = {10.1371/journal.pone.0103250}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-115782}, pages = {e103250}, year = {2014}, abstract = {The canonical Wnt/beta-catenin pathway plays a key role in the regulation of bone remodeling in mice and humans. Two transmembrane proteins that are involved in decreasing the activity of this pathway by binding to extracellular antagonists, such as Dickkopf 1 (Dkk1), are the low-density lipoprotein receptor related protein 5 (Lrp5) and Kremen 2 (Krm2). Lrp 5 deficiency (Lrp5(-/-)) as well as osteoblast-specific overexpression of Krm2 in mice (Col1a1-Krm2) result in severe osteoporosis occurring at young age. In this study, we analyzed the influence of Lrp5 deficiency and osteoblast-specific overexpression of Krm2 on fracture healing in mice using flexible and semi-rigid fracture fixation. We demonstrated that fracture healing was highly impaired in both mouse genotypes, but that impairment was more severe in Col1a1-Krm2 than in Lrp5(-/-) mice and particularly evident in mice in which the more flexible fixation was used. Bone formation was more reduced in Col1a1-Krm2 than in Lrp5(-/-) mice, whereas osteoclast number was similarly increased in both genotypes in comparison with wild-type mice. Using microarray analysis we identified reduced expression of genes mainly involved in osteogenesis that seemed to be responsible for the observed stronger impairment of healing in Col1a1-Krm2 mice. In line with these findings, we detected decreased expression of sphingomyelin phosphodiesterase 3 (Smpd3) and less active beta-catenin in the calli of Col1a1-Krm2 mice. Since Krm2 seems to play a significant role in regulating bone formation during fracture healing, antagonizing KRM2 might be a therapeutic option to improve fracture healing under compromised conditions, such as osteoporosis.}, language = {en} } @article{StaabHottowitzSohnsetal.2014, author = {Staab, Wieland and Hottowitz, Ralf and Sohns, Christian and Sohns, Jan Martin and Gilbert, Fabian and Menke, Jan and Niklas, Andree and Lotz, Joachim}, title = {Accelerometer and Gyroscope Based Gait Analysis Using Spectral Analysis of Patients with Osteoarthritis of the Knee}, series = {Journal of Physical Therapy Science}, volume = {26}, journal = {Journal of Physical Therapy Science}, number = {7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-115907}, pages = {997-1002}, year = {2014}, abstract = {[Purpose] A wide variety of accelerometer tools are used to estimate human movement, but there are no adequate data relating to gait symmetry parameters in the context of knee osteoarthritis. This study's purpose was to evaluate a 3D-kinematic system using body-mounted sensors (gyroscopes and accelerometers) on the trunk and limbs. This is the first study to use spectral analysis for data post processing. [Subjects] Twelve patients with unilateral knee osteoarthritis (OA) (10 male) and seven age-matched controls (6 male) were studied. [Methods] Measurements with 3-D accelerometers and gyroscopes were compared to video analysis with marker positions tracked by a six-camera optoelectronic system (VICON 460, Oxford Metrics). Data were recorded using the 3D-kinematic system. [Results] The results of both gait analysis systems were significantly correlated. Five parameters were significantly different between the knee OA and control groups. To overcome time spent in expensive post-processing routines, spectral analysis was performed for fast differentiation between normal gait and pathological gait signals using the 3D-kinematic system. [Conclusions] The 3D-kinematic system is objective, inexpensive, accurate and portable, and allows long-term recordings in clinical, sport as well as ergonomic or functional capacity evaluation (FCE) settings. For fast post-processing, spectral analysis of the recorded data is recommended.}, language = {en} } @article{ThibaudeauTaubenbergerHolzapfeletal.2014, author = {Thibaudeau, Laure and Taubenberger, Anna V. and Holzapfel, Boris M. and Quent, Verena M. and Fuehrmann, Tobias and Hesami, Parisa and Brown, Toby D. and Dalton, Paul D. and Power, Carl A. and Hollier, Brett G. and Hutmacher, Dietmar W.}, title = {A tissue-engineered humanized xenograft model of human breast cancer metastasis to bone}, series = {Disease Models \& Mechanisms}, volume = {7}, journal = {Disease Models \& Mechanisms}, number = {2}, doi = {10.1242/dmm.014076}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117466}, pages = {299-309}, year = {2014}, abstract = {The skeleton is a preferred homing site for breast cancer metastasis. To date, treatment options for patients with bone metastases are mostly palliative and the disease is still incurable. Indeed, key mechanisms involved in breast cancer osteotropism are still only partially understood due to the lack of suitable animal models to mimic metastasis of human tumor cells to a human bone microenvironment. In the presented study, we investigate the use of a human tissue-engineered bone construct to develop a humanized xenograft model of breast cancer-induced bone metastasis in a murine host. Primary human osteoblastic cell-seeded melt electrospun scaffolds in combination with recombinant human bone morphogenetic protein 7 were implanted subcutaneously in non-obese diabetic/severe combined immunodeficient mice. The tissue-engineered constructs led to the formation of a morphologically intact 'organ' bone incorporating a high amount of mineralized tissue, live osteocytes and bone marrow spaces. The newly formed bone was largely humanized, as indicated by the incorporation of human bone cells and human-derived matrix proteins. After intracardiac injection, the dissemination of luciferase-expressing human breast cancer cell lines to the humanized bone ossicles was detected by bioluminescent imaging. Histological analysis revealed the presence of metastases with clear osteolysis in the newly formed bone. Thus, human tissue-engineered bone constructs can be applied efficiently as a target tissue for human breast cancer cells injected into the blood circulation and replicate the osteolytic phenotype associated with breast cancer-induced bone lesions. In conclusion, we have developed an appropriate model for investigation of species-specific mechanisms of human breast cancer-related bone metastasis in vivo.}, language = {en} } @article{WirtzGraviusAscherletal.2014, author = {Wirtz, Dieter C. and Gravius, Sascha and Ascherl, Rudolf and Thorweihe, Miguel and Forst, Raimund and Noeth, Ulrich and Maus, Uwe M. and Wimmer, Matthias D. and Zeiler, Guenther and Deml, Moritz C.}, title = {Uncemented femoral revision arthroplasty using a modular tapered, fluted titanium stem 5-to 16-year results of 163 cases}, series = {Acta Orthopaedica}, volume = {85}, journal = {Acta Orthopaedica}, number = {6}, issn = {1745-3674}, doi = {10.3109/17453674.2014.958809}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-114555}, pages = {562 - 569}, year = {2014}, abstract = {Background and purpose - Due to the relative lack of reports on the medium- to long-term clinical and radiographic results of modular femoral cementless revision, we conducted this study to evaluate the medium- to long-term results of uncemented femoral stem revisions using the modular MRP-TITAN stem with distal diaphyseal fixation in a consecutive patient series. Patients and methods - We retrospectively analyzed 163 femoral stem revisions performed between 1993 and 2001 with a mean follow-up of 10 (5-16) years. Clinical assessment included the Harris hip score (HHS) with reference to comorbidities and femoral defect sizes classified by Charnley and Paprosky. Intraoperative and postoperative complications were analyzed and the failure rate of the MRP stem for any reason was examined. Results - Mean HHS improved up to the last follow-up (37 (SD 24) vs. 79 (SD 19); p < 0.001). 99 cases (61\%) had extensive bone defects (Paprosky IIB-III). Radiographic evaluation showed stable stem anchorage in 151 cases (93\%) at the last follow-up. 10 implants (6\%) failed for various reasons. Neither a breakage of a stem nor loosening of the morse taper junction was recorded. Kaplan-Meier survival analysis revealed a 10-year survival probability of 97\% (95\% CI: 95-100). Interpretation - This is one of the largest medium- to longterm analyses of cementless modular revision stems with distal diaphyseal anchorage. The modular MRP-TITAN was reliable, with a Kaplan-Meier survival probability of 97\% at 10 years.}, language = {en} } @article{ReichertSchmalzlPrageretal.2013, author = {Reichert, Johannes and Schmalzl, Jonas and Prager, Patrick and Gilbert, Fabian and Quent, Verena M. C. and Steinert, Andre F. and Rudert, Maximilian and N{\"o}th, Ulrich}, title = {Synergistic effect of Indian hedgehog and bone morphogenetic protein-2 gene transfer to increase the osteogenic potential of human mesenchymal stem cells}, series = {Stem Cell Research \& Therapy}, journal = {Stem Cell Research \& Therapy}, doi = {10.1186/scrt316}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97010}, year = {2013}, abstract = {Introduction To stimulate healing of large bone defects research has concentrated on the application of mesenchymal stem cells (MSCs). Methods In the present study, we induced the overexpression of the growth factors bone morphogenetic protein 2 (BMP-2) and/or Indian hedgehog (IHH) in human MSCs by adenoviral transduction to increase their osteogenic potential. GFP and nontransduced MSCs served as controls. The influence of the respective genetic modification on cell metabolic activity, proliferation, alkaline phosphatase (ALP) activity, mineralization in cell culture, and osteogenic marker gene expression was investigated. Results Transduction had no negative influence on cell metabolic activity or proliferation. ALP activity showed a typical rise-and-fall pattern with a maximal activity at day 14 and 21 after osteogenic induction. Enzyme activity was significantly higher in groups cultured with osteogenic media. The overexpression of BMP-2 and especially IHH + BMP-2 resulted in a significantly higher mineralization after 28 days. This was in line with obtained quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) analyses, which showed a significant increase in osteopontin and osteocalcin expression for osteogenically induced BMP-2 and IHH + BMP-2 transduced cells when compared with the other groups. Moreover, an increase in runx2 expression was observed in all osteogenic groups toward day 21. It was again more pronounced for BMP-2 and IHH + BMP-2 transduced cells cultured in osteogenic media. Conclusions In summary, viral transduction did not negatively influence cell metabolic activity and proliferation. The overexpression of BMP-2 in combination with or without IHH resulted in an increased deposition of mineralized extracellular matrix, and expression of osteogenic marker genes. Viral transduction therefore represents a promising means to increase the osteogenic potential of MSCs and the combination of different transgenes may result in synergistic effects.}, language = {en} }