Center for Orthopaedic Innovation, Mercy Medical Center, Baltimore, Maryland, USA.
Laboratory of Human Retrovirology and Immunoinformatics, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA.
Anat Rec (Hoboken). 2021 Jul;304(7):1582-1591. doi: 10.1002/ar.24549. Epub 2020 Nov 3.
Foot fat pad (FFP) is a highly functionalized fat depot of great significance for weight bearing in the foot. Mesenchymal stromal cells (MSCs) in subcutaneous adipose tissues are widely studied for regenerative potentials. MSCs in FFP, which may contribute to the physiological and pathological conditions of the foot, have not been characterized. In this study, MSCs were isolated from FFP (designated as MSCs-ffp) and subcutaneous adipose tissue (designated as MSCs-sub) from rats. The cell surface markers, proliferation, and efficiency of colony formation were compared between MSCs-ffp and MSCs-sub. In addition, MSCs-ffp were induced for osteogenic, chondrogenic, and adipogenic differentiation. The tri-lineage differentiation potentials were compared between MSCs-ffp and MSCs-sub by the expression of Runx2, Sox9, and proliferator-activated receptor gamma (PPAR-γ), respectively, using quantitative polymerized chain reaction. The expression of elastin and associated genes by MSCs-ffp were also evaluated. MSCs-ffp, like MSCs-sub, expressed CD44, CD73, and CD90. MSCs-ffp and MSCs-sub proliferated at similar rates but MSCs-ffp formed more colonies than MSCs-sub. MSCs-ffp were capable of differentiating into osteogenic, chondrogenic, and adipogenic lineages. Under the conditions of osteogenic and adipogenic differentiation, MSCs-sub expressed more Runx2 and PPAR-γ, respectively, than MSCs-ffp. The undifferentiated MSCs-ffp upregulated the expression of fibulin-5. In conclusion, MSCs-ffp shared common biology with MSCs-sub but were more efficient in colony formation, less adipogenic and osteogenic, and participated in elastogenesis. The unique features of MSCs-ffp may relate to their roles in the physiological functions of FFP.
足底脂肪垫（FFP）是一种具有重要功能的脂肪组织，对于足部承重具有重要意义。间充质基质细胞（MSCs）在皮下脂肪组织中被广泛研究，以评估其再生潜能。而 FFP 中的 MSCs 可能与足部的生理和病理状况有关，但尚未对其进行特征描述。在本研究中，我们从大鼠的 FFP（命名为 MSCs-ffp）和皮下脂肪组织（命名为 MSCs-sub）中分离出 MSCs。比较了 MSCs-ffp 和 MSCs-sub 的细胞表面标志物、增殖能力和集落形成效率。此外，我们诱导 MSCs-ffp 向成骨、成软骨和成脂分化，并通过定量聚合酶链反应分别检测 Runx2、Sox9 和过氧化物酶体增殖物激活受体γ（PPAR-γ）的表达来比较 MSCs-ffp 和 MSCs-sub 的三系分化潜能。还评估了 MSCs-ffp 中弹性蛋白及其相关基因的表达。MSCs-ffp 与 MSCs-sub 一样表达 CD44、CD73 和 CD90。MSCs-ffp 和 MSCs-sub 的增殖速度相似，但 MSCs-ffp 形成的集落比 MSCs-sub 多。MSCs-ffp 能够向成骨、成软骨和成脂谱系分化。在成骨和成脂分化条件下，MSCs-sub 表达的 Runx2 和 PPAR-γ 分别高于 MSCs-ffp。未分化的 MSCs-ffp 上调了纤维连接蛋白-5 的表达。总之，MSCs-ffp 与 MSCs-sub 具有共同的生物学特性，但集落形成效率更高，成脂和成骨能力更低，并且参与了弹性蛋白生成。MSCs-ffp 的这些独特特征可能与其在 FFP 生理功能中的作用有关。
