Department of Biophysics, PGIMER, Chandigarh, India; Department of Ophthalmology, University of Pittsburgh, USA.
Department of Nephrology, PGIMER, Chandigarh, India.
Biochimie. 2018 Dec;155:129-139. doi: 10.1016/j.biochi.2018.10.014. Epub 2018 Oct 24.
Dental stem cells (DMSC) have been studied extensively since their early discovery. However, the data regarding osteogenic potential of DMSC with other cell types is sparse and the secretome proteins underlying these differences have not been explored. In this study, we have compared the osteogenic and adipogenic potential of DMSC with Bone Marrow Stem cells (BMSC) and reported the contribution of secretome proteins in controlling their differentiation.
Osteogenic potential of these stem cells was compared by mineralization assay, alkaline phosphatase (ALP) assay, immunofluorescence of dentine sialo phosphoprotein (DSPP) & qPCR for osteogenic genes. Adipogenic potential was compared by Oil Red O staining and qPCR for PPAR-γ, leptin & adipsin. Proteomic analysis of secretome was performed by employing WATERS nano Lc-MS/MS system.
We observed a higher osteogenic potential in DMSC, especially dental pulp stem cells (DPSC) as compared to BMSC population but adipogenic potential was found to be better in BMSC as compared to DMSC. Deeper investigations into secretome of these cells by Lc-MS/MS revealed the presence of proteins pertaining to osteogenic and adipogenic lineage. Presence of some important proteins regulating osteogenic (DSPP, BMP7, DDR2, USP9X) and adipogenic differentiation (NCOA2, PEG10, LPA) in secretome of BMSC and DMSC reflected the role of paracrine factors during differentiation.
Our study provides first evidence regarding regulation of osteogenic/adipogenic potential by secretome proteins in DMSC and BMSC. DMSC especially DPSC and its secretome show an inherent tendency for higher osteogenic differentiation and lower adipogenic differentiation, these may be potential candidates for effective future therapy in osteoporosis where disturbance of osteocyte/adipocyte homeostasis is reported.
自早期发现以来，牙源性干细胞（DMSC）已被广泛研究。然而，关于 DMSC 与其他细胞类型的成骨潜能的数据很少，并且尚未探索这些差异背后的分泌蛋白组。在这项研究中，我们比较了 DMSC 与骨髓基质细胞（BMSC）的成骨和成脂潜能，并报告了分泌蛋白组在控制其分化中的作用。
通过矿化测定、碱性磷酸酶（ALP）测定、牙本质涎磷蛋白（DSPP）的免疫荧光和骨形成基因的 qPCR 比较这些干细胞的成骨潜能。通过油红 O 染色和 PPAR-γ、瘦素和脂联素的 qPCR 比较成脂潜能。通过采用沃特世纳诺 LC-MS/MS 系统进行分泌组的蛋白质组学分析。
我们观察到 DMSC，尤其是牙髓干细胞（DPSC）的成骨潜能明显高于 BMSC 群体，但 BMSC 的成脂潜能明显优于 DMSC。通过 LC-MS/MS 对这些细胞的分泌组进行更深入的研究发现，存在与成骨和成脂谱系相关的蛋白质。BMSC 和 DMSC 分泌组中存在一些重要的蛋白质，这些蛋白质调节成骨（DSPP、BMP7、DDR2、USP9X）和脂肪生成分化（NCOA2、PEG10、LPA），反映了旁分泌因子在分化过程中的作用。
我们的研究首次提供了关于 DMSC 和 BMSC 中分泌蛋白组调节成骨/成脂潜能的证据。DMSC 特别是 DPSC 及其分泌组显示出更高的成骨分化和更低的成脂分化的内在趋势，这些可能是骨质疏松症有效未来治疗的潜在候选者，因为骨细胞/脂肪细胞的动态平衡失调在骨质疏松症中有所报道。
