2015年6月18日訊 /生物谷BIOON/ --近日,來自美國印第安納大學醫學院的研究人員在國際學術期刊Cell在線發表了一項最新研究進展。
本文亮點:
●暴露在環境空氣中會降低從骨髓和臍帶血中獲得造血幹細胞的效率
●在空氣收集造血幹細胞會使造血幹細胞數目被大大低估
●由ROS介導的造血幹細胞數目下降與cypd-p53-mptp軸,miR210和hif-1a有關
●在環胞素a中收集造血幹細胞可以提高造血幹細胞移植效率
造血幹細胞駐留在骨髓和臍帶血的低氧環境中,但幾乎所有的造血幹細胞研究都是在非生理條件的環境空氣中進行造血幹細胞的分離和篩選。
在該項研究中,研究人員在低氧條件下對骨髓和臍帶血進行了收集和操作,證明將骨髓和臍帶血暴露在環境空氣中會降低造血幹細胞長期擴增過程的細胞得率,同時會增加祖細胞的數量,研究人員將這種現象稱為非生理學氧氣應激(EPHOSS,extraphysiologic oxygen shock/stress)。因此,骨髓和臍帶血中造血幹細胞的數量一直都被低估。
隨後,研究人員通過親環素d(cyclophilin d)和p53將ros的產生和線粒體通透性轉換孔(MPTP)聯繫在一起作為EPHOSS的分子機制進行了實驗探究。MPTP抑制劑--環胞素a能夠保證在空氣中收集小鼠骨髓和人類臍帶血中的造血幹細胞時避免發生EPHOSS反應,從而增加了可用於移植的造血幹細胞數目。
綜上所述,這項研究發現EPHOSS反應會導致從骨髓和臍帶血中收集到的造血幹細胞數目減少,而在收集過程中加入環胞素a可以保證造血幹細胞免受EPHOSS反應的影響,從而增加造血幹細胞移植效率,因此這項研究對於造血幹細胞移植具有非常重要的應用價值。(生物谷Bioon.com)
Enhancing Hematopoietic Stem Cell Transplantation Efficacy by Mitigating Oxygen Shock
Charlie R. Mantel10, Heather A. O'Leary10, Brahmananda R. Chitteti, XinXin Huang, Scott Cooper, Giao Hangoc, Nickolay Brustovetsky, Edward F. Srour, Man Ryul Lee, Steven Messina-Graham, David M. Haas, Nadia Falah, Reuben Kapur, Louis M. Pelus, Nabeel Bardeesy, Julien Fitamant, Mircea Ivan, Kye-Seong Kim, Hal E. Broxmeyer
Hematopoietic stem cells (HSCs) reside in hypoxic niches within bone marrow and cord blood. Yet, essentially all HSC studies have been performed with cells isolated and processed in non-physiologic ambient air. By collecting and manipulating bone marrow and cord blood in native conditions of hypoxia, we demonstrate that brief exposure to ambient oxygen decreases recovery of long-term repopulating HSCs and increases progenitor cells, a phenomenon we term extraphysiologic oxygen shock/stress (EPHOSS). Thus, true numbers of HSCs in the bone marrow and cord blood are routinely underestimated. We linked ROS production and induction of the mitochondrial permeability transition pore (MPTP) via cyclophilin D and p53 as mechanisms of EPHOSS. The MPTP inhibitor cyclosporin A protects mouse bone marrow and human cord blood HSCs from EPHOSS during collection in air, resulting in increased recovery of transplantable HSCs. Mitigating EPHOSS during cell collection and processing by pharmacological means may be clinically advantageous for transplantation.