组织来源决定间充质干细胞的分化潜能：骨髓和脂肪组织来源的人骨髓间充质干细胞的比较研究。

BACKGROUND: Mesenchymal stem cells (MSCs) possess intrinsic regeneration capacity as part of the repair process in response to injury, such as fracture or other tissue injury. Bone marrow and adipose tissue are the major sources of MSCs. However, which cell type is more effective and suitable for cell therapy remains to be answered. The intrinsic molecular mechanism supporting the assertion has also been lacking. METHODS: Human bone marrow-derived MSCs (BMSCs) and adipose tissue-derived MSCs (ATSCs) were isolated from bone marrow and adipose tissue obtained after total hip arthroplasty. ATSCs and BMSCs were incubated in standard growth medium. Trilineage differentiation including osteogenesis, adipogenesis, and chondrogenesis was performed by addition of relevant induction mediums. The expression levels of trilineage differentiation marker genes were evaluated by quantitative RT-PCR. The methylation status of CpG sites of Runx2, PPARγ, and Sox9 promoters were checked by bisulfite sequencing. In addition, ectopic bone formation and calvarial bone critical defect models were used to evaluate the bone regeneration ability of ATSCs and BMSCs in vivo. RESULTS: The results showed that BMSCs possessed stronger osteogenic and lower adipogenic differentiation potentials compared to ATSCs. There was no significant difference in the chondrogenic differentiation potential. The CpG sites of Runx2 promoter in BMSCs were hypomethylated, while in ATSCs they were hypermethylated. The CpG sites of PPARγ promoter in ATSCs were hypomethylated, while in BMSCs they were hypermethylated. The methylation status of Sox9 promoter in BMSCs was only slightly lower than that in ATSCs. CONCLUSIONS: The epigenetic memory obtained from either bone marrow or adipose tissue favored MSC differentiation along an osteoblastic or adipocytic lineage. The methylation status of the main transcription factors controlling MSC fate contributes to the differential differentiation capacities of different source-derived MSCs.

背景：间充质干细胞（MSCs）具有内在的再生能力，是对损伤（如骨折或其他组织损伤）反应过程中的修复的一部分。骨髓和脂肪组织是 MSCs 的主要来源。然而，哪种细胞类型更有效和适合细胞治疗仍有待回答。支持这一说法的内在分子机制也一直缺乏。

方法：从全髋关节置换术后获得的骨髓和脂肪组织中分离出人骨髓源性 MSCs（BMSCs）和脂肪组织源性 MSCs（ATSCs）。将 ATSCs 和 BMSCs 孵育在标准生长培养基中。通过添加相关诱导培养基，进行三系分化，包括成骨、成脂和成软骨分化。通过定量 RT-PCR 评估三系分化标记基因的表达水平。通过亚硫酸氢盐测序检查 Runx2、PPARγ 和 Sox9 启动子的 CpG 位点的甲基化状态。此外，还使用异位骨形成和颅骨骨临界缺损模型来评估 ATSCs 和 BMSCs 在体内的骨再生能力。

结果：结果表明，与 ATSCs 相比，BMSCs 具有更强的成骨和更低的成脂分化潜力。其软骨分化潜力没有显著差异。BMSCs 中 Runx2 启动子的 CpG 位点呈低甲基化状态，而 ATSCs 中则呈高甲基化状态。ATSCs 中 PPARγ 启动子的 CpG 位点呈低甲基化状态，而 BMSCs 中则呈高甲基化状态。BMSCs 中 Sox9 启动子的甲基化状态仅略低于 ATSCs。

结论：从骨髓或脂肪组织获得的表观遗传记忆使 MSC 分化倾向于成骨细胞或脂肪细胞谱系。控制 MSC 命运的主要转录因子的甲基化状态有助于不同来源衍生的 MSCs 的分化能力差异。