Extracellular matrix mineralization promotes E11/gp38 glycoprotein expression and drives osteocytic differentiation.
Extracellular matrix mineralization promotes E11/gp38 glycoprotein expression and drives osteocytic differentiation.
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DOI：
10.1371/journal.pone.0036786
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Farquharson C
中科院分区：
文献类型：
--
作者：
Prideaux M;Loveridge N;Pitsillides AA;Farquharson C
骨细胞是终末分化的成骨细胞，存在于矿化的细胞外基质(ECM)中。调控这一分化过程的因素尚不清楚。我们已经研究了细胞外基质矿化是否可以促进骨细胞的形成。为此，我们利用MLO-A5前骨样细胞、Western blotting和比较RT-PCR来检测骨细胞选择性标记物的表达是否与ECM矿化的开始同时升高。其次，如果ECM的矿化确实是骨细胞形成的驱动因素，我们推测ECM矿化的损害将导致骨细胞形成的可逆抑制。在培养的MLO-A5细胞中添加抗坏血酸和磷酸盐，可促进细胞外基质的渐进性矿化，并促进骨细胞选择性标志物E11/gp38糖蛋白和硬化素的表达。与ECM矿化在骨细胞形成中的主要作用一致，我们还发现，通过省略磷酸盐或添加公认的羟基磷灰石形成抑制剂焦磷酸钠来抑制ECM矿化，可以导致矿物质沉积减少15倍，同时伴随着E11和其他骨细胞标记物如Dmp1、CD44和SOST表达的降低，而成骨细胞标记物OCN和Col1a的表达增加。为了排除这种对ECM矿化的限制可能会对成骨细胞的行为产生不可逆转的改变，从而限制E11的表达和成骨细胞的生成，我们还测量了MLO-A5细胞重新进入骨细胞分化计划的能力。我们发现，重新给予磷酸盐或省略焦磷酸钠后，矿化过程重新启动，并与E11蛋白的表达增加密切相关，表明细胞外基质矿化诱导了骨细胞形成的修复。这些结果强调了细胞-ECM相互作用在调节成骨细胞行为中的重要性，更重要的是，表明ECM矿化在成骨细胞终末分化和获得成骨细胞表型的过程中起着关键的控制作用。
Osteocytes are terminally differentiated osteoblasts which reside in a mineralized extracellular matrix (ECM). The factors that regulate this differentiation process are unknown. We have investigated whether ECM mineralization could promote osteocyte formation. To do this we have utilised MLO-A5 pre-osteocyte-like cells and western blotting and comparative RT-PCR to examine whether the expression of osteocyte-selective markers is elevated concurrently with the onset of ECM mineralization. Secondly, if mineralization of the ECM is indeed a driver of osteocyte formation, we reasoned that impairment of ECM mineralization would result in a reversible inhibition of osteocyte formation. Supplementation of MLO-A5 cell cultures with ascorbic acid and phosphate promoted progressive ECM mineralization as well as temporally associated increases in expression of the osteocyte-selective markers, E11/gp38 glycoprotein and sclerostin. Consistent with a primary role for ECM mineralization in osteocyte formation, we also found that inhibition of ECM mineralization, by omitting phosphate or adding sodium pyrophosphate, a recognized inhibitor of hydroxyapatite formation, resulted in a 15-fold decrease in mineral deposition that was closely accompanied by lower expression of E11 and other osteocyte markers such as Dmp1, Cd44 and Sost whilst expression of osteoblast markers Ocn and Col1a increased. To rule out the possibility that such restriction of ECM mineralization may produce an irreversible modification in osteoblast behaviour to limit E11 expression and osteocytogenesis, we also measured the capacity of MLO-A5 cells to re-enter the osteocyte differentiation programme. We found that the mineralisation process was re-initiated and closely allied to increased expression of E11 protein after re-administration of phosphate or omission of sodium pyrophosphate, indicating an ECM mineralization-induced restoration in osteocyte formation. These results emphasise the importance of cell-ECM interactions in regulating osteoblast behaviour and, more importantly, suggest that ECM mineralization exerts pivotal control during terminal osteoblast differentiation and acquisition of the osteocyte phenotype.
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影响因子：
3.3
作者：
Martín-Villar E;Fernández-Muñoz B;Parsons M;Yurrita MM;Megías D;Pérez-Gómez E;Jones GE;Quintanilla M
通讯作者：
Quintanilla M
影响因子：
6.2
作者：
Kato, Y;Boskey, K;Bonewald, LF
通讯作者：
Bonewald, LF
DOI：
10.1002/ar.a.20032
发表时间：
2004-05-01
期刊：
ANATOMICAL RECORD PART A-DISCOVERIES IN MOLECULAR CELLULAR AND EVOLUTIONARY BIOLOGY
影响因子：
--
作者：
Palumbo, C;Ferretti, M;Marotti, G
通讯作者：
Marotti, G
影响因子：
3.3
作者：
Hirao, Makoto;Hashimoto, Jun;Yoshikawa, Hideki
通讯作者：
Yoshikawa, Hideki
DOI：
10.1152/ajpendo.00008.2006
发表时间：
2006-07-01
影响因子：
5.1
作者：
Liu, Shiguang;Zhou, Jianping;Quarles, L. Darryl
通讯作者：
Quarles, L. Darryl