日本京都大學研究人員在新一期《細胞－幹細胞》雜誌網絡版上發表論文說，在培育誘導多能幹細胞（iPS細胞）的過程中，通過降低培養環境的氧濃度，可大幅提高細胞生成的效率。
京都大學教授山中伸彌等人在iPS細胞研究過程中，發現機體內的幹細胞總是集中於氧氣相對少的地方。於是，他們在利用人體皮膚細胞培養iPS細胞時把培養環境的氧濃度從通常的21％降到5％，發現iPS細胞的生成效率可提高到原來的2．5倍至4．2倍。但如果進一步降低氧濃度到1％，就會適得其反導致部分細胞死亡。研究人員又利用實驗鼠的皮膚細胞培養iPS細胞，發現5％的氧濃度也是最合適的。
通過基因重新編排方法，「誘導」普通細胞回到最原始的胚胎發育狀態，能夠像胚胎幹細胞一樣進行分化，這就是所謂的iPS細胞。日本、美國等國的多個科研小組正在進行各項研究，將iPS細胞應用於新藥開發和疑難疾病治療。但iPS細胞生成效率低的問題一直沒有得到解決。
山中伸彌等人認為，通過降低培養環境的氧濃度，再加上使用細胞癌變可能性較小的培養方法，就可高效地獲取更高品質的iPS細胞。（生物谷Bioon.com）
生物谷推薦原始出處：
Cell Stem Cell, 27 August 2009 doi:10.1016/j.stem.2009.08.001
Hypoxia Enhances the Generation of Induced Pluripotent Stem Cells
Yoshinori Yoshida1,,,Kazutoshi Takahashi1,Keisuke Okita1,Tomoko Ichisaka2andShinya Yamanaka1,2,3,4,,
1 Center for iPS Cell Research and Application (CiRA), Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8507, Japan
2 Yamanaka iPS Cell Special Project, Japan Science and Technology Agency, Kawaguchi 332-0012, Japan
3 Department of Stem Cell Biology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
4 Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA
Mouse and human somatic cells can be reprogrammed to induced pluripotent stem cells (iPSCs) by the transduction of four transcription factors, Oct 3/4, Sox2, Klf4, and c-Myc (Maherali etal., 2007,Meissner etal., 2007,Okita etal., 2007,Takahashi etal., 2007,Takahashi and Yamanaka, 2006,Wernig etal., 2007). Patient or disease-specific human iPSCs could be used for studying pathogenesis, or potentially also to treat patients suffering from incurable diseases by transplanting the regenerated grafts derived from their own cells. However, the low induction efficiency and high tumorigenesis rate due to the use of proto-oncogenes, such as c-Myc, continue to hinder the clinical application of iPS technology. Many efforts have been made to find otherfactors or small molecules that facilitate the reprogramming process (Huangfu etal., 2008,Shi etal., 2008b). In this study, we show that conducting reprogramming in hypoxic conditions results in improved efficiency for both mouse and human cells.