Evaluation of optimal concentration and exposure duration of valproic acid alone or in combination with ViraDuctin to augment adenovirus transduction in human adipose stem cells

Background aimsRecombinant adenoviruses have tremendous potential in both gene therapy research and therapeutic applications. Mesenchymal stromal cells have a set of several properties that make them ideally suited for both regenerative medicine and gene and drug delivery. A limitation of adenoviral-mediated gene transfer is indeed the poor transduction rate of cells with low or no levels of the specific adenoviral cell surface receptor coxsackie virus and adenovirus receptor (CAR), such as human mesenchymal stromal cells. In the present work, we tried to increase the adenovirus transduction level and mediated gene delivery of human adipose stem cells with the use of valproic acid (VPA) and determined the proper concentration and duration of treatment alone or in combination with ViraDuctin adenovirus transduction reagent.MethodsGreen fluorescent protein–expressing recombinant adenovirus was propagated. The effects of various doses and exposure periods of VPA on CAR expression in human adipose stem cells were speculated by quantitative real-time polymerase chain reaction and adenoviral transduction rate by flow cytometry in different doses and time intervals of VPA and in combination with ViraDuctin transduction reagent.ResultsCAR messenger RNA upregulation through VPA was observed in human adipose stem cells; it was a dependent factor of dose and exposure time. Consequently, adenoviral transduction level of human adipose stem cells treated with VPA was increased, and co-administration of VPA and ViraDuctin further enhanced the transduction rate.ConclusionsThese results confirm that addition of VPA to hASCs alone or in combination with ViraDuctin has enhancing effects on adenoviral transduction rate, which can be auspicious in adenoviral-mediated gene therapy.