@article{WangStoecklLietal.2022,
  author    = {Wang, Chenglong and St{\"o}ckl, Sabine and Li, Shushan and Herrmann, Marietta and Lukas, Christoph and Reinders, Yvonne and Sickmann, Albert and Gr{\"a}ssel, Susanne},
  title     = {Effects of extracellular vesicles from osteogenic differentiated human BMSCs on osteogenic and adipogenic differentiation capacity of na{\"i}ve human BMSCs},
  series = {Cells},
  volume    = {11},
  journal   = {Cells},
  number    = {16},
  issn      = {2073-4409},
  doi       = {10.3390/cells11162491},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-286112},
  year      = {2022},
  abstract  = {Osteoporosis, or steroid-induced osteonecrosis of the hip, is accompanied by increased bone marrow adipogenesis. Such a disorder of adipogenic/osteogenic differentiation, affecting bone-marrow-derived mesenchymal stem cells (BMSCs), contributes to bone loss during aging. Here, we investigated the effects of extracellular vesicles (EVs) isolated from human (h)BMSCs during different stages of osteogenic differentiation on the osteogenic and adipogenic differentiation capacity of na{\"i}ve (undifferentiated) hBMSCs. We observed that all EV groups increased viability and proliferation capacity and suppressed the apoptosis of na{\"i}ve hBMSCs. In particular, EVs derived from hBMSCs at late-stage osteogenic differentiation promoted the osteogenic potential of na{\"i}ve hBMSCs more effectively than EVs derived from na{\"i}ve hBMSCs (na{\"i}ve EVs), as indicated by the increased gene expression of COL1A1 and OPN. In contrast, the adipogenic differentiation capacity of na{\"i}ve hBMSCs was inhibited by treatment with EVs from osteogenic differentiated hBMSCs. Proteomic analysis revealed that osteogenic EVs and na{\"i}ve EVs contained distinct protein profiles, with pro-osteogenic and anti-adipogenic proteins encapsulated in osteogenic EVs. We speculate that osteogenic EVs could serve as an intercellular communication system between bone- and bone-marrow adipose tissue, for transporting osteogenic factors and thus favoring pro-osteogenic processes. Our data may support the theory of an endocrine circuit with the skeleton functioning as a ductless gland.},
  language  = {en}
}
@article{NiedermairLukasLietal.2020,
  author    = {Niedermair, Tanja and Lukas, Christoph and Li, Shushan and St{\"o}ckl, Sabine and Craiovan, Benjamin and Brochhausen, Christoph and Federlin, Marianne and Herrmann, Marietta and Gr{\"a}ssel, Susanne},
  title     = {Influence of Extracellular Vesicles Isolated From Osteoblasts of Patients With Cox-Arthrosis and/or Osteoporosis on Metabolism and Osteogenic Differentiation of BMSCs},
  series = {Frontiers in Bioengineering and Biotechnology},
  volume    = {8},
  journal   = {Frontiers in Bioengineering and Biotechnology},
  issn      = {2296-4185},
  doi       = {10.3389/fbioe.2020.615520},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-219902},
  year      = {2020},
  abstract  = {Background: Studies with extracellular vesicles (EVs), including exosomes, isolated from mesenchymal stem cells (MSC) indicate benefits for the treatment of musculoskeletal pathologies as osteoarthritis (OA) and osteoporosis (OP). However, little is known about intercellular effects of EVs derived from pathologically altered cells that might influence the outcome by counteracting effects from "healthy" MSC derived EVs. We hypothesize, that EVs isolated from osteoblasts of patients with hip OA (coxarthrosis/CA), osteoporosis (OP), or a combination of both (CA/OP) might negatively affect metabolism and osteogenic differentiation of bone-marrow derived (B)MSCs. Methods: Osteoblasts, isolated from bone explants of CA, OP, and CA/OP patients, were compared regarding growth, viability, and osteogenic differentiation capacity. Structural features of bone explants were analyzed via μCT. EVs were isolated from supernatant of na{\"i}ve BMSCs and CA, OP, and CA/OP osteoblasts (osteogenic culture for 35 days). BMSC cultures were stimulated with EVs and subsequently, cell metabolism, osteogenic marker gene expression, and osteogenic differentiation were analyzed. Results: Trabecular bone structure was different between the three groups with lowest number and highest separation in the CA/OP group. Viability and Alizarin red staining increased over culture time in CA/OP osteoblasts whereas growth of osteoblasts was comparable. Alizarin red staining was by trend higher in CA compared to OP osteoblasts after 35 days and ALP activity was higher after 28 and 35 days. Stimulation of BMSC cultures with CA, OP, and CA/OP EVs did not affect proliferation but increased caspase 3/7-activity compared to unstimulated BMSCs. BMSC viability was reduced after stimulation with CA and CA/OP EVs compared to unstimulated BMSCs or stimulation with OP EVs. ALP gene expression and activity were reduced in BMSCs after stimulation with CA, OP, and CA/OP EVs. Stimulation of BMSCs with CA EVs reduced Alizarin Red staining by trend. Conclusion: Stimulation of BMSCs with EVs isolated from CA, OP, and CA/OP osteoblasts had mostly catabolic effects on cell metabolism and osteogenic differentiation irrespective of donor pathology and reflect the impact of tissue microenvironment on cell metabolism. These catabolic effects are important for understanding differences in effects of EVs on target tissues/cells when harnessing them as therapeutic drugs.},
  language  = {en}
}
@article{EbertBenischKrugetal.2015,
  author    = {Ebert, Regina and Benisch, Peggy and Krug, Melanie and Zeck, Sabine and Meißner-Weigl, Jutta and Steinert, Andre and Rauner, Martina and Hofbauer, Lorenz and Jakob, Franz},
  title     = {Acute phase serum amyloid A induces proinflammatory cytokines and mineralization via toll-like receptor 4 in mesenchymal stem cells},
  series = {Stem Cell Research},
  volume    = {15},
  journal   = {Stem Cell Research},
  doi       = {10.1016/j.scr.2015.06.008},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-148491},
  pages     = {231-239},
  year      = {2015},
  abstract  = {The role of serum amyloid A (SAA) proteins, which are ligands for toll-like receptors, was analyzed in human bone marrow-derived mesenchymal stem cells (hMSCs) and their osteogenic offspring with a focus on senescence, differentiation andmineralization. In vitro aged hMSC developed a senescence-associated secretory phenotype (SASP), resulting in enhanced SAA1/2, TLR2/4 and proinflammatory cytokine (IL6, IL8, IL1\(\beta\), CXCL1, CXCL2) expression before entering replicative senescence. Recombinant human SAA1 (rhSAA1) induced SASP-related genes and proteins in MSC, which could be abolished by cotreatment with the TLR4-inhibitor CLI-095. The same pattern of SASP-resembling genes was stimulated upon induction of osteogenic differentiation, which is accompanied by autocrine SAA1/2 expression. In this context additional rhSAA1 enhanced the SASP-like phenotype, accelerated the proinflammatory phase of osteogenic differentiation and enhanced mineralization. Autocrine/paracrine and rhSAA1 via TLR4 stimulate a proinflammatory phenotype that is both part of the early phase of osteogenic differentiation and the development of senescence. This signaling cascade is tightly involved in bone formation and mineralization, but may also propagate pathological extraosseous calcification conditions such as calcifying inflammation and atherosclerosis.},
  language  = {en}
}