Martin J, Helm K, Ruegg P, Varella-Garcia M, Burnham E, Majka S
Division of Cardiology, Cardiovascular Pulmonary Laboratory, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA.
Cytotherapy. 2008;10(2):140-51. doi: 10.1080/14653240801895296.
The development of stem cell therapy for pulmonary diseases remains a challenge. Many diverse cell types reside within the lung and a common stem cell has not yet been identified. A basic understanding of lung stem cell fate during disease may prove important for drug intervention as well as autologous therapies. Niches for resident mesenchymal stem cells (MSC) have been identified in many adult tissues and more recently in the lung. We present data to confirm the observation that non-hematopoietic CD45(neg) lung side population (SP) cells contain MSC, single cells capable of multilineage differentiation. METHODS We carried these observations forward by analyzing the MSC potential of single-cell clones, as well as their chromosomal stability and telomerase activity.
The expression of MSC markers was characterized in mouse CD45(neg) lung SP by flow cytometry on freshly isolated or cultured clonal populations. The karyotype of these cells was subsequently assayed by banding analysis, and telomerase activity was assessed using quantitative polymerase chain reaction. MSC differentiation potential was confirmed by the characteristic ability of single-cell clones to differentiate into cells of three mesenchymal lineages, chondrocytes, adipocytes and osteocytes. Differentiation was confirmed by histochemical analysis. All analyzed populations of CD45(neg) lung SP expressed mesenchymal markers (CD44, CD90, CD105, CD106, CD73 and Sca-I) and lacked hematopoietic markers (CD45, c-kit, CD11b, CD34 and CD14). The cultured and clonal CD45(neg) lung SP had normal chromosomal structures and expressed high levels of telomerase. After being expanded and cultured in differentiation medium, all populations of CD45(neg) lung SP demonstrated adipogenic, osteogenic and chrondrogenic potential. Adult CD45(neg) lung SP cells are a source of MSC.
In defining this tissue-specific stem cell population in the lung, we are now better able to clarify a potential role for them in lung diseases.
肺部疾病的干细胞疗法发展仍然是一项挑战。肺内存在多种不同类型的细胞，尚未确定共同的干细胞。深入了解疾病期间肺干细胞的命运对于药物干预以及自体疗法可能具有重要意义。在许多成体组织中已确定了驻留间充质干细胞（MSC）的生态位，最近在肺中也有发现。我们提供数据以证实非造血性CD45阴性肺侧群（SP）细胞包含能够进行多谱系分化的单个间充质干细胞这一观察结果。方法我们通过分析单细胞克隆的MSC潜能、其染色体稳定性和端粒酶活性来推进这些观察。
通过对新鲜分离或培养的克隆群体进行流式细胞术分析，在小鼠CD45阴性肺SP中表征了MSC标志物的表达。随后通过显带分析检测这些细胞的核型，并使用定量聚合酶链反应评估端粒酶活性。单细胞克隆分化为三种间充质谱系细胞（软骨细胞、脂肪细胞和骨细胞）的特征性能力证实了MSC的分化潜能。通过组织化学分析确认了分化。所有分析的CD45阴性肺SP群体均表达间充质标志物（CD44、CD90、CD105、CD106、CD73和Sca-1），且缺乏造血标志物（CD45、c-kit、CD11b、CD34和CD14）。培养的克隆性CD45阴性肺SP具有正常的染色体结构并表达高水平的端粒酶。在分化培养基中扩增培养后，所有CD45阴性肺SP群体均表现出成脂、成骨和成软骨潜能。成年CD45阴性肺SP细胞是MSC的一个来源。
在确定肺中这种组织特异性干细胞群体时，我们现在能够更好地阐明它们在肺部疾病中的潜在作用。
