United Kingdom Centre for Tissue Engineering, University of Manchester, Manchester, UK.
Cell Prolif. 2012 Apr;45(2):111-20. doi: 10.1111/j.1365-2184.2011.00804.x. Epub 2012 Jan 20.
Mesenchymal stem cells are able to undergo adipogenic differentiation and present a possible alternative cell source for regeneration and replacement of adipose tissue. The human infrapatellar fat pad is a promising source of mesenchymal stem cells with many source advantages over from bone marrow. It is important to determine whether a potential mesenchymal stem-cell exhibits tri-lineage differentiation potential and is able to maintain its proliferation potential and cell-surface characterization on expansion in tissue culture. We have previously shown that mesenchymal stem cells derived from the fat pad can undergo chondrogenic and osteogenic differentiation, and we characterized these cells at early passage. In the study described here, proliferation potential and characterization of fat pad-derived mesenchymal stem cells were assessed at higher passages, and cells were allowed to undergo adipogenic differentiation.
Infrapatellar fat pad tissue was obtained from six patients undergoing total knee replacement. Cells isolated were expanded to passage 18 and proliferation rates were measured. Passage 10 and 18 cells were characterized for cell-surface epitopes using a range of markers. Passage 2 cells were allowed to undergo differentiation in adipogenic medium.
The cells maintained their population doubling rates up to passage 18. Cells at passage 10 and passage 18 had cell-surface epitope expression similar to other mesenchymal stem cells previously described. By staining it was revealed that they highly expressed CD13, CD29, CD44, CD90 and CD105, and did not express CD34 or CD56, they were also negative for LNGFR and STRO1. 3G5 positive cells were noted in cells from both passages. These fat pad-derived cells had adipogenic differentiation when assessed using gene expression for peroxisome proliferator-activated receptor γ2 and lipoprotein lipase, and oil red O staining.
These results indicate that the cells maintained their proliferation rate, and continued expressing mesenchymal stem-cell markers and pericyte marker 3G5 at late passages. These results also show that the cells were capable of adipogenic differentiation and thus could be a promising source for regeneration and replacement of adipose tissue in reconstructive surgery.
间充质干细胞能够进行脂肪向分化，并为脂肪组织的再生和替代提供一种可能的替代细胞来源。人髌下脂肪垫是间充质干细胞的一个很有前途的来源，与骨髓来源相比具有许多优势。重要的是要确定潜在的间充质干细胞是否具有三系分化潜能，并能够在组织培养中保持其增殖潜能和细胞表面特征。我们之前已经表明，脂肪垫来源的间充质干细胞可以进行软骨和成骨分化，并且我们在早期传代时对这些细胞进行了特征描述。在本研究中，评估了脂肪垫来源的间充质干细胞在较高传代时的增殖潜能和特征，并允许它们进行脂肪向分化。
从 6 名接受全膝关节置换术的患者中获取髌下脂肪垫组织。分离的细胞进行扩增至传代 18，并测量增殖率。使用一系列标记物对传代 10 和 18 的细胞进行细胞表面表型特征分析。将传代 2 的细胞置于脂肪向分化培养基中进行分化。
细胞维持其倍增率直至传代 18。传代 10 和传代 18 的细胞具有与先前描述的其他间充质干细胞相似的细胞表面表型特征。通过染色发现，它们高度表达 CD13、CD29、CD44、CD90 和 CD105，不表达 CD34 或 CD56，也为阴性 LNGFR 和 STRO1。在两个传代的细胞中均观察到 3G5 阳性细胞。使用过氧化物酶体增殖物激活受体 γ2 和脂蛋白脂酶的基因表达以及油红 O 染色评估时，这些脂肪垫来源的细胞具有脂肪向分化能力。
这些结果表明，细胞在晚期传代时保持其增殖率，并继续表达间充质干细胞标志物和周细胞标志物 3G5。这些结果还表明，细胞能够进行脂肪向分化，因此可能是重建和替代整形外科中脂肪组织的有前途的来源。
