Characterization of human mesenchymal stem cell secretome at early steps of adipocyte and osteoblast differentiation
Characterization of human mesenchymal stem cell secretome at early steps of adipocyte and osteoblast differentiation
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DOI：
10.1186/1471-2199-9-26
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发表时间：
2008-02-26
影响因子：
--
通讯作者：
Amri, Ez-Zoubir
中科院分区：
文献类型：
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作者：
Chiellini, Chiara;Cochet, Olivia;Amri, Ez-Zoubir
背景资料：众所周知，脂肪组织在能量储存和释放中起关键作用，但也是分泌器官和干细胞的来源。在不同的谱系中，干细胞能够分化成脂肪细胞和成骨细胞。由于分泌的蛋白质可以调节两个谱系之间的平衡，我们的目的是在表征人多能脂肪源性干细胞（hMADS）的分泌组的早期步骤的承诺，脂肪细胞和成骨细胞。结果：蛋白质组学的方法，使用单向电泳和串联质谱，使我们能够确定共73个蛋白在第0天和第3天的脂肪细胞和成骨细胞分化。分析鉴定的蛋白质表明，52%对应于经典的分泌蛋白，其特征在于信号肽，37%以前描述的细胞外室中没有信号肽，11%既没有表现出信号肽，也没有以前描述的细胞外。这些蛋白质根据其功能分为8个簇。已对8个候选物进行定量分析：派-1、PEDF、BIGH 3、PTX 3、ENOI、GRP 78和MMP 2。其中派-1在成骨细胞分化的第0天和第3天表达，而在脂肪细胞分泌组未见表达。此外，我们发现，派-1 mRNA在卵巢切除小鼠的骨下调。结论：鉴于其在hMADS细胞分化的早期事件和其在卵巢切除小鼠的状态，派-1可以发挥作用，在脂肪细胞/成骨细胞的平衡，从而在骨疾病，如骨质疏松症。
Background: It is well established that adipose tissue plays a key role in energy storage and release but is also a secretory organ and a source of stem cells. Among different lineages, stem cells are able to differentiate into adipocytes and osteoblasts. As secreted proteins could regulate the balance between both lineages, we aimed at characterizing the secretome of human multipotent adipose-derived stem cell (hMADS) at an early step of commitment to adipocytes and osteoblasts.Results: A proteomic approach, using mono-dimensional electrophoresis and tandem mass spectrometry, allowed us to identify a total of 73 proteins at day 0 and day 3 of adipocyte and osteoblast differentiation. Analysis of identified proteins showed that 52% corresponded to classical secreted proteins characterized by a signal peptide, that 37% previously described in the extracellular compartment were devoid of signal peptide and that 11% neither exhibited a signal peptide nor had been previously described extracellularly. These proteins were classified into 8 clusters according to their function. Quantitative analysis has been performed for 8 candidates: PAI-1, PEDF, BIGH3, PTX3, SPARC, ENOI, GRP78 and MMP2. Among them, PAI-1 was detected at day 0 and day 3 of osteoblast differentiation but never in adipocyte secretome. Furthermore we showed that PAI-1 mRNA was down-regulated in the bone of ovariectomized mice.Conclusion: Given its regulation during the early events of hMADS cell differentiation and its status in ovariectomized mice, PAI-1 could play a role in the adipocyte/osteoblast balance and thus in bone diseases such as osteoporosis.