ASC spheroid geometry and culture oxygenation differentially impact induction of preangiogenic behaviors in endothelial cells.
ASC spheroid geometry and culture oxygenation differentially impact induction of preangiogenic behaviors in endothelial cells.
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DOI：
10.3727/096368914x684051
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发表时间：
2015
影响因子：
3.3
通讯作者：
Blanchette JO
中科院分区：
文献类型：
--
作者：
Skiles ML;Hanna B;Rucker L;Tipton A;Brougham-Cook A;Jabbarzadeh E;Blanchette JO
基于细胞的血管生成疗法为缺血性损伤的修复提供了潜力，同时避免了与基于材料的生长因子输送策略相关的几个限制。有证据表明，使用MSCs作为球状细胞而不是分散的细胞可以通过增加缺氧引起的血管生成因子的分泌来改善保留率和提高治疗效果。然而，尽管球体培养似乎调节了MSC的行为，但关于影响细胞氧张力的主要培养参数，如外部氧合和培养大小，如何影响球体的血管生成潜力的研究很少。我们在20%和2%的氧气中培养了相同数量的脂肪干细胞(ASCs)，每个球体包含10,000(10K)或60,000(60K)个细胞。不同样本组的血管内皮生长因子分泌情况不同，10K、2%O2球体的分泌量最高。将球体条件培养液应用于HUVEC单层，并检测其增殖情况。与2 ng/mlVEGF对照样品相比，在2%氧气中，两种大小的球体均可诱导类似的增殖，而在20%氧气中，球体诱导的增殖较少。球体也被应用于与HUVEC单层共培养，并评估了通过Transwell膜的迁移诱导。6万个、2%O2球体诱导的迁移水平与血管内皮生长因子对照组相似，而10K、2%O2球体诱导的迁移程度显著高于对照组。10000个、20%的球体的表现并不比不含血管内皮生长因子的对照组好。我们的结论是，ASC球体刺激内皮细胞血管生成的治疗能力受到培养大小和氧合参数的影响，这表明，尽管ASC球体在治疗损伤和缺血组织方面具有潜力，但为了获得最佳结果，必须仔细考虑培养大小与体内局部氧分压的关系。
Cell-based angiogenic therapies offer potential for the repair of ischemic injuries, while avoiding several of the limitations associated with material-based growth factor delivery strategies. Evidence supports that applying MSCs as spheroids rather than dispersed cells can improve retention and enhance therapeutic effect through increased secretion of angiogenic factors due to hypoxia. However, while spheroid culture appears to modulate MSC behavior, there has been little investigation of how major culture parameters that affect cellular oxygen tension, such as external oxygenation and culture size, impact the angiogenic potential of spheroids. We cultured equal numbers of adipose-derived stem cells (ASCs) as spheroids containing 10,000 (10k) or 60,000 (60k) cells each, in 20% and 2% oxygen. VEGF secretion varied among the sample groups, with 10k, 2% O2 spheroids exhibiting the highest production. Spheroid-conditioned media was applied to HUVEC monolayers, and proliferation was assessed. Spheroids of either size in 2% oxygen induced comparable proliferation compared to a 2 ng/ml VEGF control sample, while spheroids in 20% oxygen induced less proliferation. Spheroids were also applied in coculture with HUVEC monolayers, and induction of migration through a Transwell membrane was evaluated. Sixty thousand, 2% O2 spheroids induced similar levels of migration as VEGF controls, while 10k, 2% O2 spheroids induced significantly more. Ten thousand, 20% spheroids performed no better than VEGF-free controls. We conclude that the therapeutic ability of ASC spheroids to stimulate angiogenesis in endothelial cells is affected by both culture size and oxygenation parameters, suggesting that, while ASC spheroids offer potential in the treatment of injured and ischemic tissues, careful consideration of culture size in respect to in vivo local oxygen tension will be necessary for optimal results.