@article{discovery10064406, year = {2016}, volume = {31}, month = {April}, journal = {European Cells and Materials}, pages = {221--235}, title = {Differences in human mesenchymal stem cell secretomes during chondrogenic induction}, note = {This is the published version of record. For information on re-use, please refer to the publisher's terms and conditions.}, author = {Gardner, OFW and Fahy, N and Alini, M and Stoddart, MJ}, url = {https://doi.org/10.22203/eCM.v031a15}, abstract = {Mesenchymal stem cells (MSCs) can be induced towards chondrogenesis through the application of chondrogenic stimuli such as transforming growth factor-{\ensuremath{\beta}} (TGF-{\ensuremath{\beta}}) or by multiaxial mechanical load. Previous work has showed that the chondrogenic effect of multiaxial load on MSCs is mediated by the endogenous production of TGF-{\ensuremath{\beta}}1 by stimulated cells. This work compared the effects of TGF-{\ensuremath{\beta}}1 stimulation and multiaxial mechanical load on the secretomes of stimulated cells. MSCs were seeded into fibrin-poly(ester-urethane) scaffolds and chondrogenically stimulated with either TGF-{\ensuremath{\beta}}1 or mechanical load. The culture media was collected and analysed for 174 proteins using a cytokine antibody array. The results of the secretome analysis were then confirmed at a gene expression level by real-time PCR. As results implicated nitric oxide (NO), the media nitrite content was also determined as an indirect measurement of media NO levels. Results showed that TGF-{\ensuremath{\beta}}1 stimulation and mechanical load lead to similar changes in factors such as BLC, VEGF and MMP13, whilst differences in detected levels were seen for factors including leptin, MDC, MIP3{\ensuremath{\alpha}} and LAP. Gene expression analysis confirmed significant changes in four factors: angiopoietin 2, GRO{\ensuremath{\alpha}}, MMP13 and osteoprotegerin. After one week in culture the media nitrite content was significantly higher in loaded groups than both control and TGF-{\ensuremath{\beta}}1 stimulated groups, suggesting this may be a major therapeutic target. These data show that despite clear similarities, TGF-{\ensuremath{\beta}}1 stimulation and load have distinct effects on MSCs and are not analogous. This study has identified a number of potentially novel targets for tissue engineering, these data may also be useful for improving rehabilitation protocols e.g. after microfracture.}, issn = {1473-2262}, keywords = {Secretome, paracrine signalling, regenerative medicine, cartilage repair, cytokines.} }