美国埃默里大学一个科研小组11日报告说，他们通过动物实验发现，取自猴子牙髓的干细胞可以刺激脑细胞的形成和生长。
研究小组在新一期《干细胞》杂志上介绍说，研究人员把取自恒河猴牙齿的牙髓干细胞植入实验鼠大脑中的海马区。结果发现，这些干细胞能够刺激生成几种类型的新神经细胞。
牙髓干细胞是存在于牙髓组织中的一种成体干细胞，可分化形成多种细胞类型。医学研究认为，牙髓干细胞具有重要的治疗潜力。此前，牙髓干细胞已应用于牙齿和颅面细胞的再生。研究小组说，他们的新研究结果表明，牙髓干细胞将来有望应用于细胞疗法和再生医疗领域，尤其是治疗与中枢神经系统相关的一些疾病。
研究小组还指出，牙髓干细胞提取方便，医生可以十分方便地从患者牙齿中分离出牙髓干细胞。因此，他们认为可尝试设立牙髓干细胞“银行”，人们一旦患病，就可以提取自己事先保存的牙髓干细胞用于治疗。自体干细胞治疗可大大降低目前移植医学领域常见的细胞排异反应。
接下来，该研究小组还计划进行实验，从患有亨廷顿病（一种遗传性脑病）猴子的牙齿中提取牙髓干细胞，观察患病猴子的牙髓干细胞是否也能像健康猴子的牙髓干细胞那样刺激大脑细胞发育。（生物谷Bioon.com）
生物谷推荐原始出处：
Stem Cells Vol. 26 No. 10 October 2008, pp. 2654 -2663
Putative Dental Pulp-Derived Stem/Stromal Cells Promote Proliferation and Differentiation of Endogenous Neural Cells in the Hippocampus of Mice
Anderson Hsien-Cheng Huanga,b, Brooke R. Snyderc,g, Pei-Hsun Chengc, Anthony W.S. Chancf
aGrace Dental Clinic, Kaohsiung City, Taiwan;
bDepartment of Oral Pathology, School of Dentistry, Kaohsiung Medical University, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan;
cYerkes National Primate Research Center,
dDepartment of Human Genetics,
eGenetics and Molecular Biology Program, and
fNeuroscience Program, Emory University School of Medicine, Atlanta, Georgia, USA;
gCenter for Gene Therapy, Tulane University, New Orleans, Louisiana, USA
Until now, interest in dental pulp stem/stromal cell (DPSC) research has centered on mineralization and tooth repair. Beginning a new paradigm in DPSC research, we grafted undifferentiated, untreated DPSCs into the hippocampus of immune-suppressed mice. The rhesus DPSC (rDPSC) line used was established from the dental pulp of rhesus macaques and found to be similar to human bone marrow/mesenchymal stem cells, which express Nanog, Rex-1, Oct-4, and various cell surface antigens, and have multipotent differentiation capability. Implantation of rDPSCs into the hippocampus of mice stimulated proliferation of endogenous neural cells and resulted in the recruitment of pre-existing Nestin+ neural progenitor cells (NPCs) and β-tubulin-III+ mature neurons to the site of the graft. Additionally, many cells born during the first 7 days after implantation proliferated, forming NPCs and neurons, and, to a lesser extent, underwent astrogliosis, forming astrocytes and microglia, by 30 days after implantation. Although the DPSC graft itself was short term, it had long-term effects by promoting growth factor signaling. Implantation of DPSCs enhanced the expression of ciliary neurotrophic factor, vascular endothelial growth factor, and fibroblast growth factor for up to 30 days after implantation. In conclusion, grafting rDPSCs promotes proliferation, cell recruitment, and maturation of endogenous stem/progenitor cells by modulating the local microenvironment. Our results suggest that DPSCs have a valuable, unique therapeuticpotential, specifically as a stimulator and modulator of the local repair response in the central nervous system. DPSCs would be a preferable cell source for therapy due to the possibility of a "personalized" stem cell, avoiding the problems associated with host immune rejection.
