Fibroblast-myofibroblast crosstalk after exposure to mesenchymal stem cells secretome.

Aim: The aim of the present study was to investigate the effect of human bone marrow-derived mesenchymal stem cells conditioned medium on fibroblast to myofibroblast differentiation.

Background: Mesenchymal stem cells have a long-term clinical application and widely have used in autoimmune disease and regenerative medicine. However, some MSCs derived cytokines such as TGF-β could have a dual role in suppression or progression of disease. Fibroblast activation and extracellular matrix production are two key features of wound healing which mostly are controlled with multifunctional cytokine TGF-β1.

Methods: Bone marrow MSCs were isolated, cultured and used for conditioned medium preparation. The flow cytometry analysis was done for MSCs cell surface markers. MRC-5 subconfluent cells were starved with the medium containing 0.5 % FBS for 24h, then treated with exogenous TGF-β1 (10ng/ml as positive control) and MSCs-conditioned medium for 48h. Finally, the mRNA expression of three target genes: collagen I, collagen III and α-SMA were evaluated by RT-PCR technique.

Results: Our findings demonstrated that bone marrow-derived mesenchymal stem cells-conditioned medium (secretome) significantly upregulated type I and III collagen expression but non-significantly α-SMA gene expression.

Conclusion: Totally, Real Time PCR results suggest that MSCs conditioned medium activates differentiation of fibroblast to myofibroblast phenotype as confirmed through the presence of α-SMA, collagen I and collagen III expression compared to control in MRC 5 cells.