Hyperoxic or hypoxic environment?

摘要

We read the article by Khan et al. (2017) in a recent issue of this journal with great interest. We would like to congratulate the authors for this report. In the article, the authors focused primarily on the characteristics of adiposederived mesenchymal stem cells (Ad-MSCs) by altering culture environment. The results of the study showed that culture medium containing 0.5% gelatin enhanced the proliferation rate, induced immunosuppression, and activated BMP-7 and the wnt/AXIN/β-catenin pathway in Ad-MSCs. However, we believe there is a misunderstanding in the introduction section of the article. A review of the literature shows that certain characteristics of MSCs can be modified with altered culture environments or preconditioned incubation processes. Khan et al. also cited a review published by Song et al. in 2010, as mentioned in the Introduction. This study indicated that preconditioning MSCs under hypoxicconditions enhanced the activity of the MSCs, suggesting anew perspective for the cellular treatment of cardiac tissuedamages. In this review, hypoxic conditions were shown tohave cytoprotective effects for MSCs, regulated paracrinefactors, and increased the VEGF secretion (Song et al.,2010). Likewise, several studies with different designs inthe literature yielded similar results (Kadle et al., 2016;Ciria et al., 2017). Therefore, we believe that the term“hyperoxic conditions” mentioned in the introduction ofKhan et al.’s article (in citation to the study of Song et al.)is confusing. We recommend that this erroneous term becorrected to prevent any misunderstanding for the readers.We believe that the authors of the article would regardour opinion as a contribution.