Cyclic tensile strain upon human mesenchymal stem cells in 2D and 3D culture differentially influences CCNL2, WDR61 and BAHCC1 gene expression levels

• Published in: Journal of the mechanical behavior of biomedical materials Vol. 11; pp. 82 - 91
• Main Authors: Rathbone, Sarah R., Glossop, John R., Gough, Julie E., Cartmell, Sarah H.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.07.2012
• Subjects: BAHCC1; Cell Count; Cell Culture Techniques - methods; Cell Survival - drug effects; Culture; Cyclin L2; Cyclins - genetics; Dynamics; Force; Gene expression; Gene Expression Regulation - drug effects; Humans; Hydrogels; Hydrogels - pharmacology; Mesenchymal stem cell; Mesenchymal Stromal Cells - cytology; Mesenchymal Stromal Cells - drug effects; Mesenchymal Stromal Cells - metabolism; Proteins - genetics; Stem cells; Strain; Stress, Mechanical; Tensile Strength - drug effects; Three dimensional; Transcription Factors - genetics; Two dimensional; WDR61; Mesenchymal stem cell; WDR61; Gene expression; Force; BAHCC1; Cyclin L2
• ISSN: 1751-6161; 1878-0180
• DOI: 10.1016/j.jmbbm.2012.01.019

It has been shown that tensile strain can alter cell behaviour. Evidence exists to confirm that human mesenchymal stem cells can be encouraged to differentiate in response to tensile loading forces. We have investigated the short-term effects of cyclic tensile strain (3%, 1 Hz) on gene expression in primary human mesenchymal stem cells in monolayer and whilst encapsulated in a self-assembled peptide hydrogel. The main aims of the project were to gain the following novel information: (1) to determine if the genes CCNL2, WDR61 and BAHCC1 are potentially important mechanosensitive genes in monolayer, (2) to determine if these genes showed the same differential expression in a 3D environment (either tethered to RGD or simply encapsulated within a hydrogel (with RGE motif)) and (3) to determine whether the mesenchymal stem cells would survive within the hydrogels over several days whilst enduring dynamic culture. In the monolayer system, real-time PCR confirmed CCNL2 was significantly downregulated after 1 h strain and 2 h latency (post strain). BAHCC1 was significantly downregulated after 1 h strain (both 2 h and 24 h latency). WDR61 followed the same trend in 2D culture. After 24 h strain and 2 h latency, BAHCC1 was significantly upregulated. We found that both types of peptide hydrogel supported viable mesenchymal stem cells over 48 h. Results of the 3D dynamic culture did not correspond with those of the 2D dynamic culture, where the BAHCC1 gene was not expressed in the 3D experiments. The disparity in the differential gene expression observed between the 2D and 3D culture systems may partly be a result of the different cellular environments in each. It is likely that cells cultured within an intricate 3D architecture respond to mechanical cues in a different and more complex manner than do cells in 2D monolayer, as is illustrated by our gene expression data. [Display omitted] ► Gene expression study of tensile loading of MSCs in peptide hydrogels (3%, 1Hz). ► Peptide hydrogels supported viable MSCs in 3D culture over a 48 h period. ► MSCs cultured in 3D responded to strain differently than did cells in 2D monolayers. ► 1 h straining of 2D cultures significantly affected gene expression levels. ► 1 h straining of 3D constructs had little effect on gene expression levels.