Background

Mesenchymal stem cells (MSCs) can be easily expanded. They can be acquired from medical waste such as adipose and umbilical cord tissues, are influenced by culturing conditions, and exert anti-inflammatory, antioxidant, anti-fibrotic, and angiogenic effects. We analyzed the multi-directional effects of MSCs cultured under hypoxic conditions and their underlying mechanisms in the treatment of liver cirrhosis in a mouse model.

Methods

Human bone marrow-derived MSCs cultured under hypoxic (5% O₂; hypoMSCs) and normoxic (21% O₂; norMSCs) conditions were compared by cap analysis of gene expression (CAGE) with or without serum from liver cirrhosis patients. The therapeutic effects of MSCs, including serum liver enzyme induction, fibrosis regression, and hepatic oxidative stress, were evaluated by injecting 1 × 10⁶, 2 × 10⁵, or 4 × 10⁴ MSCs/mouse into the tail veins of mice with carbon tetrachloride (CCl₄)-induced liver cirrhosis. Intravital imaging was performed with a two-photon excitation microscope to confirm the various MSC migration paths to the liver.

Results

CAGE analysis revealed that the RNA expression levels of prostaglandin E synthase (Ptges) and miR210 were significantly higher in hypoMSCs than in norMSCs. In vivo analysis revealed that both hypoMSCs and norMSCs reduced serum alanine aminotransferase, oxidative stress, and fibrosis compared to that in control mice in a dose-dependent manner. However, hypoMSCs had stronger therapeutic effects than norMSCs. We confirmed this observation by an in vitro study in which hypoMSCs changed macrophage polarity to an anti-inflammatory phenotype via prostaglandin E2 (PGE2) stimulation. In addition, miR210 reduced the rate of hepatocyte apoptosis. Intravital imaging after MSC administration showed that both cell types were primarily trapped in the lungs. Relatively a few hypoMSCs and norMSCs migrated to the liver. There were no significant differences in their distributions.

Conclusion

The therapeutic effect of hypoMSCs was mediated by PGE2 and miR210 production and was greater than that of norMSCs. Therefore, MSCs can be manipulated to improve their therapeutic efficacy in the treatment of liver cirrhosis and could potentially serve in effective cell therapy. MSCs produce several factors with multidirectional effects and function as “conducting cells” in liver cirrhosis.

中文翻译：

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与常氧条件下培养的间充质干细胞相比，低氧条件下培养的间充质干细胞对肝硬化小鼠的治疗效果更好。

背景

间充质干细胞 (MSCs) 可以很容易地扩增。它们可以从脂肪和脐带组织等医疗废物中获得，受培养条件的影响，具有抗炎、抗氧化、抗纤维化和血管生成的作用。我们分析了低氧条件下培养的 MSCs 的多向效应及其在小鼠模型中治疗肝硬化的潜在机制。

方法

_{通过基因表达的上限分析 (CAGE) 比较了在缺氧（5% O 2}；hypoMSCs）和常氧（21% O ₂ ；norMSCs）条件下培养的人骨髓来源的 MSCs ，无论有无来自肝硬化患者的血清。MSCs的治疗效果，包括血清肝酶诱导、纤维化消退和肝脏氧化应激，通过将1×10 ⁶、2×10 ⁵或4×10 ⁴ MSCs/小鼠注射到碳小鼠尾静脉中来评估四氯化物（CCl ₄）诱导的肝硬化。用双光子激发显微镜进行活体成像，以确认各种 MSC 迁移到肝脏的路径。

结果

CAGE 分析显示，hypoMSCs 中前列腺素 E 合酶 ( Ptges ) 和 miR210 的 RNA 表达水平显着高于 norMSCs。体内分析显示，与对照小鼠相比，hypoMSCs 和 norMSCs 均以剂量依赖性方式降低血清丙氨酸氨基转移酶、氧化应激和纤维化。然而，hypoMSCs 比 norMSCs 具有更强的治疗效果。我们通过体外证实了这一观察结果研究其中hypoMSCs通过前列腺素E2（PGE2）刺激将巨噬细胞极性改变为抗炎表型。此外，miR210 降低肝细胞凋亡率。MSC 给药后的活体成像显示两种细胞类型主要被困在肺部。相对少量的hypoMSCs和norMSCs迁移到肝脏。它们的分布没有显着差异。

结论

hypoMSCs 的治疗效果是由 PGE2 和 miR210 的产生介导的，并且优于 norMSCs。因此，MSCs 可以被操纵以提高其在肝硬化治疗中的治疗效果，并可能用于有效的细胞治疗。间充质干细胞产生多种具有多向效应的因子，在肝硬化中起到“传导细胞”的作用。