Myocardial Ischemic Subject’s Thymus Fat: A Novel Source of Multipotent Stromal Cells

ObjectiveAdipose Tissue Stromal Cells (ASCs) have important clinical applications in the regenerative medicine, cell replacement and gene therapies. Subcutaneous Adipose Tissue (SAT) is the most common source of these cells. The adult human thymus degenerates into adipose tissue (TAT). However, it has never been studied before as a source of stem cells.Material and MethodsWe performed a comparative characterization of TAT-ASCs and SAT-ASCs from myocardial ischemic subjects (n = 32) according to the age of the subjects.ResultsTAT-ASCs and SAT-ASCs showed similar features regarding their adherence, morphology and in their capacity to form CFU-F. Moreover, they have the capacity to differentiate into osteocyte and adipocyte lineages; and they present a surface marker profile corresponding with stem cells derived from AT; CD73+CD90+CD105+CD14-CD19-CD45-HLA-DR. Interestingly, and in opposition to SAT-ASCs, TAT-ASCs have CD14+CD34+CD133+CD45- cells. Moreover, TAT-ASCs from elderly subjects showed higher adipogenic and osteogenic capacities compared to middle aged subjects, indicating that, rather than impairing; aging seems to increase adipogenic and osteogenic capacities of TAT-ASCs.ConclusionsThis study describes the human TAT as a source of mesenchymal stem cells, which may have an enormous potential for regenerative medicine.研究目的 脂肪组织基质细胞（Adipose Tissue Stromal Cells, ASCs）在再生医学、细胞替代治疗与基因治疗领域具有重要临床应用价值。皮下脂肪组织（Subcutaneous Adipose Tissue, SAT）是这类细胞最常见的获取来源。成人胸腺退变后可转化为脂肪组织（Thymic Adipose Tissue, TAT），但此前尚未有研究将其作为干细胞来源开展相关探索。 材料与方法 本研究针对32名心肌缺血受试者，按受试者年龄分层，对胸腺脂肪组织来源的ASCs（TAT-ASCs）与皮下脂肪组织来源的ASCs（SAT-ASCs）开展了比较性表征分析。 结果 TAT-ASCs与SAT-ASCs在贴壁特性、形态特征及形成CFU-F（成纤维细胞集落形成单位）的能力方面表现相似。两类细胞均具备向成骨细胞与脂肪细胞谱系分化的潜能，且表面标志物谱符合脂肪组织来源干细胞的特征：CD73+CD90+CD105+CD14-CD19-CD45-HLA-DR。值得关注的是，与SAT-ASCs不同，TAT-ASCs中存在CD14+CD34+CD133+CD45-的细胞亚群。进一步分析显示，老年受试者来源的TAT-ASCs其成脂与成骨分化能力均高于中年受试者，提示衰老非但未损害TAT-ASCs的分化潜能，反而似乎增强了其成脂与成骨能力。 结论 本研究首次证实人类胸腺退变形成的脂肪组织可作为间充质干细胞的可靠来源，其在再生医学领域具备巨大的应用潜力。