Objective: The aim of this study was to characterize and differentiate adipose-derived stem cells (ADSCs) to functional smooth muscle cells (SMCs) as an alternative cell source for bladder engineering.
Materials and methods: Rat ADSCs were differentiated into SMCs for 1-6 weeks using induction medium. The changes in contractile genes and protein expression were investigated by real-time polymerase chain reaction, fluorescence-activated cell sorting and Western blot at different time-points. Spontaneous and carbachol-induced contractions of engineered SMC tissue at different stages were investigated to define the optimal duration of induction.
Results: ADSCs differentiated into SMCs lost their capacity for expansion and their contractile phenotype, changing to a synthetic phenotype over time. Highest levels of calponin, smoothelin and MyH11 expression were observed in ADSCs induced for 3 weeks. Cells acquired typical SMC morphology when contractile proteins were expressed. However, SMC morphology was lost with reduction of contractile proteins, especially smoothelin and MyH11. The maximal spontaneous and carbachol-induced contraction of differentiated ADSCs was after 3 weeks.
Conclusions: This study demonstrates that ADCSs are a suitable cell source for engineering tissues that require functional and contractile SMCs. An induction time of 3 weeks appears to be sufficient for ADSC differentiation to contractile SMCs suitable for urological tissue engineering.
Keywords: adipose-derived stem cell; differentiation; smooth muscle; tissue engineering.