NOTCH Signaling Is Activated through Mechanical Strain in Human Bone Marrow-Derived Mesenchymal Stromal Cells

Figure 4

Effect of NOTCH inhibition on mechanotransduction (donor #09-donor #12). (a) Relative mRNA expression of the NOTCH target genes HEY1, HEY2, and HEYL in BMSCs from four representative donors after stretching and GSI inhibition as described in (b). Results are shown as mean of technical and normalized to basal activity (DMSO treated, nonstretched, dashed line). Fold change was calculated with the method, and RPS27A served as the housekeeping gene. (b) Relative mRNA expression of the PTGS2 gene in BMSCs. Cells were treated with 2 μM and 4 μM GSI XII or the solvent DMSO and received cyclic stretching. Samples were collected 4 h later. Results are shown as mean of four donors (#09- and normalized to basal activity (DMSO or GSI XII treated, nonstretched, dashed line). Fold change was calculated with the method, and RPS27A served as the housekeeping gene. Two-tailed unpaired -test was used for statistical analysis (: stretched compared to nonstretched, : DMSO control compared to 4 μM GSI XII). (c) hMSC-TERT-AP-1 cells were treated with 2 μM and 4 μM GSI XII or DMSO as solvent and received cyclic stretching. Luciferase activity was determined and normalized to protein content. Data are expressed as mean of four independent and normalized to nonstretched, untreated controls (first column). Each measurement was performed in technical quadruplicate (: stretched compared to nonstretched, : DMSO control compared to 2 μM or 4 μM GSI XII).

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