Johannes Zellner

Dr. Johannes Zellner


Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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20 April 2010 in Cells Tissues Organs
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Journal Article
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MMMichael B. Mueller
Michael B. Mueller
MFMaria Fischer
Maria Fischer
JZJohannes Zellner
Johannes Zellner
ABArne Berner
Arne Berner
TDThomas Dienstknecht
Thomas Dienstknecht
PAPeter Angele
Peter Angele
Induction of chondrogenesis in mesenchymal stem cells (MSCs) with TGF-β leads to a hypertrophic phenotype. The hypertrophic maturation of the chondrocytes is dependent on the timed removal of TGF-β and sensitive to hypertrophy-promoting agents in vitro. In this study, we have investigated whether TGF-β3, which has been shown to be more prochondrogenic compared to TGF-β1, similarly enhances terminal differentiation in an in vitro hypertrophy model of chondrogenically differentiating MSCs. In addition, we tested the impact of the time of chondrogenic conditioning on the enhancement of hypertrophy. MSCs were chondrogenically differentiated in pellet culture in medium containing TGF-β1 or TGF-β3. After 2 or 4 weeks, chondrogenic medium was switched to hypertrophy-inducing medium for 2 weeks. Aggregates were analyzed histologically and biochemically on days 14, 28 and 42. The switch to hypertrophy medium after 14 days induced hypertrophic cell morphology and significant increase in alkaline phosphatase activity compared to the chondrogenesis only control using both TGF-β1 and TGF-β3. After 28 days predifferentiation, differences between hypertrophic and control groups diminished compared to 14 days predifferentiation. In conclusion, chondrogenic conditioning with both TGF-β isoforms similarly induced hypertrophy in our experiment and allowed the enhancement of the hypertrophic chondrocyte phenotype by hypertrophic medium. Enhancement of hypertrophy was seen more clearly after the shorter chondrogenic conditioning. Therefore, to utilize this experimental model as a tool to study hypertrophy in MSC chondrogenesis, a predifferentiation period of 14 days is recommended.

2 August 2010 in Journal of Biomedical Materials Research Part A
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Journal Article
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JZJohannes Zellner
Johannes Zellner
MMMichael Mueller
Michael Mueller
ABArne Berner
Arne Berner
TDThomas Dienstknecht
Thomas Dienstknecht
RKRichard Kujat
Richard Kujat
PAPeter Angele
Peter Angele

29 August 2007 in Journal of Biomedical Materials Research Part A
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Journal Article
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PAPeter Angele
Peter Angele
BJBrian Johnstone
Brian Johnstone
RKRichard Kujat
Richard Kujat
JZJohannes Zellner
Johannes Zellner
MNMichael Nerlich
Michael Nerlich
JYJung Yoo
Jung Yoo

6 April 2013 in Journal of Biomedical Materials Research Part B: Applied Biomaterials
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Journal Article
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JZJohannes Zellner
Johannes Zellner
KHKatja Hierl
Katja Hierl
MMMichael Mueller
Michael Mueller
CPChristian Pfeifer
Christian Pfeifer
ABArne Berner
Arne Berner
PAPeter Angele
Peter Angele

16 April 2016 in Knee Surgery, Sports Traumatology, Arthroscopy
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Journal Article
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RVRene Verdonk
Rene Verdonk
Henning MadryHenning Madry
Henning Madry
NSNogah Shabshin
Nogah Shabshin
FDFlorian Dirisamer
Florian Dirisamer
GPGiuseppe Michele Peretti
Giuseppe Michele Peretti
PAPeter Angele
Peter Angele

17 May 2011 in Cell and tissue research
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Journal Article
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PDF file
ABArne Berner
Arne Berner
JRJohannes C. Reichert
Johannes C. Reichert
MMMichael B. Müller
Michael B. Müller
JZJohannes Zellner
Johannes Zellner
CPChristian Pfeifer
Christian Pfeifer
BFBernd Füchtmeier
Bernd Füchtmeier