@article{MuellerDeubertSeefriedKrugetal.2017,
  author    = {M{\"u}ller-Deubert, Sigrid and Seefried, Lothar and Krug, Melanie and Jakob, Franz and Ebert, Regina},
  title     = {Epidermal growth factor as a mechanosensitizer in human bone marrow stromal cells},
  series = {Stem Cell Research},
  volume    = {24},
  journal   = {Stem Cell Research},
  doi       = {10.1016/j.scr.2017.08.012},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170247},
  pages     = {69-76},
  year      = {2017},
  abstract  = {Epidermal growth factors (EGFs) e.g. EGF, heparin-binding EGF and transforming growth factor alpha and their receptors e.g. EGFR and ErbB2 control proinflammatory signaling and modulate proliferation in bone marrow stromal cells (BMSC). Interleukin-6 and interleukin-8 are EGF targets and participate in the inflammatory phase of bone regeneration via non-canonical wnt signaling. BMSC differentiation is also influenced by mechanical strain-related activation of ERK1/2 and AP-1, but the role of EGFR signaling in mechanotransduction is unclear. We investigated the effects of EGFR signaling in telomerase-immortalized BMSC, transfected with a luciferase reporter, comprising a mechanoresponsive AP1 element, using ligands, neutralizing antibodies and EGFR inhibitors on mechanotransduction and we found that EGF via EGFR increased the response to mechanical strain. Results were confirmed by qPCR analysis of mechanoresponsive genes. EGF-responsive interleukin-6 and interleukin-8 were synergistically enhanced by EGF stimulation and mechanical strain. We show here in immortalized and primary BMSC that EGFR signaling enhances mechanotransduction, indicating that the EGF system is a mechanosensitizer in BMSC. Alterations in mechanosensitivity and -adaptation are contributors to age-related diseases like osteoporosis and the identification of a suitable mechanosensitizer could be beneficial. The role of the synergism of these signaling cascades in physiology and disease remains to be unraveled.},
  language  = {en}
}
@article{MuelekSeefriedGenestetal.2017,
  author    = {M{\"u}lek, Melanie and Seefried, Lothar and Genest, Franca and H{\"o}gger, Petra},
  title     = {Distribution of constituents and metabolites of maritime pine bark extract (Pycnogenol\(^{®}\)) into serum, blood cells, and synovial fluid of patients with severe osteoarthritis: a randomized controlled trial},
  series = {Nutrients},
  volume    = {9},
  journal   = {Nutrients},
  number    = {5},
  doi       = {10.3390/nu9050443},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-159862},
  pages     = {443},
  year      = {2017},
  abstract  = {The present randomized controlled study aimed to investigate the in vivo distribution of constituents or metabolites of the standardized maritime pine bark extract Pycnogenol\(^{®}\). Thirty-three patients with severe osteoarthritis scheduled for a knee arthroplasty were randomized to receive either 200 mg per day Pycnogenol\(^{®}\) (P+) or no treatment (Co) over three weeks before surgery. Serum, blood cells, and synovial fluid samples were analyzed using liquid chromatography coupled to tandem mass spectrometry with electrospray ionization (LC-ESI/MS/MS). Considerable interindividual differences were observed indicating pronounced variability of the polyphenol pharmacokinetics. Notably, the highest polyphenol concentrations were not detected in serum. Catechin and taxifolin primarily resided within the blood cells while the microbial catechin metabolite δ-(3,4-dihydroxy-phenyl)-γ-valerolactone, ferulic, and caffeic acid were mainly present in synovial fluid samples. Taxifolin was detected in serum and synovial fluid exclusively in the P+ group. Likewise, no ferulic acid was found in serum samples of the Co group. Calculating ratios of analyte distribution in individual patients revealed a simultaneous presence of some polyphenols in serum, blood cells, and/or synovial fluid only in the P+ group. This is the first evidence that polyphenols distribute into the synovial fluid of patients with osteoarthritis which supports rationalizing the results of clinical efficacy studies.},
  language  = {en}
}
@article{JessbergerHoeggerGenestetal.2017,
  author    = {Jessberger, Steffen and H{\"o}gger, Petra and Genest, Franca and Salter, Donald M. and Seefried, Lothar},
  title     = {Cellular pharmacodynamic effects of Pycnogenol\(^{®}\) in patients with severe osteoarthritis: a randomized controlled pilot study},
  series = {BMC Complementary and Alternative Medicine},
  volume    = {17},
  journal   = {BMC Complementary and Alternative Medicine},
  number    = {537},
  doi       = {10.1186/s12906-017-2044-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-159532},
  year      = {2017},
  abstract  = {Background: The standardized maritime pine bark extract (Pycnogenol\(^{®}\)) has previously shown symptom alleviating effects in patients suffering from moderate forms of knee osteoarthritis (OA). The cellular mechanisms for this positive impact are so far unknown. The purpose of the present randomized pilot controlled study was to span the knowledge gap between the reported clinical effects of Pycnogenol\(^{®}\) and its in vivo mechanism of action in OA patients. Methods: Thirty three patients with severe OA scheduled for a knee arthroplasty either received 100 mg of Pycnogenol\(^{®}\) twice daily or no treatment (control group) three weeks before surgery. Cartilage, synovial fluid and serum samples were collected during surgical intervention. Relative gene expression of cartilage homeostasis markers were analyzed in the patients' chondrocytes. Inflammatory and cartilage metabolism mediators were investigated in serum and synovial fluid samples. Results: The oral intake of Pycnogenol\(^{®}\) downregulated the gene expression of various cartilage degradation markers in the patients' chondrocytes, the decrease of MMP3, MMP13 and the pro-inflammatory cytokine IL1B were statistically significant (p ≤ 0.05). Additionally, protein concentrations of ADAMTS-5 in serum were reduced significantly (p ≤ 0.05) after three weeks intake of the pine bark extract. Conclusions: This is the first report about positive cellular effects of a dietary supplement on key catabolic and inflammatory markers in patients with severe OA. The results provide a rational basis for understanding previously reported clinical effects of Pycnogenol\(^{®}\) on symptom scores of patients suffering from OA.},
  language  = {en}
}