Spatial heterogeneity in the canalicular density of the osteocyte network in human osteons.
Spatial heterogeneity in the canalicular density of the osteocyte network in human osteons.
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DOI：
10.1016/j.bonr.2017.03.001
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发表时间：
2017-06
期刊：
影响因子：
2.5
通讯作者：
Weinkamer R
中科院分区：
文献类型：
--
作者：
Repp F;Kollmannsberger P;Roschger A;Kerschnitzki M;Berzlanovich A;Gruber GM;Roschger P;Wagermaier W;Weinkamer R
骨细胞在矿化的骨基质中相互连接形成复杂的细胞网络。骨细胞网络的一个重要功能是骨重塑的机械调节，其中可能的机制包括流体流过容纳细胞网络的孔隙-骨细胞腔隙-小管网络（OLCN）。在我们的研究中，OLCN在人类骨单位的三维成像的目的是获得骨单位内的小管密度和空间变化的定量描述。OLCN的拓扑结构是通过首先用罗丹明对骨样品进行染色，然后用共聚焦激光扫描显微镜对OLCN进行成像，最后使用图像分析来获得网络的去离子化版本以供进一步分析来确定的。共49个骨单位进行了研究，从股骨皮质骨的四个不同的中年健康妇女。以单位体积内小管长度表示的平均小管密度为0.074 ± 0.015 μm/μm3（相当于74 km/cm 3）。小管密度与骨单位的大小和骨细胞陷窝所占的体积分数之间没有相关性。在骨单位内，小管密度变化很大，区域较大，没有任何网络。平均而言，当从哈佛氏管向外朝向骨水泥线移动时，小管密度降低。我们假设，由于微晶化，可接近的小管随着组织年龄的增加而减少，可以降低骨的局部机械敏感性。未来对OLCN拓扑结构上与年龄和疾病相关的变化的系统研究必须证明所提出的表征方法的诊断潜力。使用共聚焦显微镜和图像分析的小管网络拓扑结构的精确三维表示在健康人骨单位中平均小管密度为74 km/cm 3的定量网络描述骨单位内小管密度的显著变化为10%密度为骨单位平均值两倍的骨中，发现缺乏可及网络的大区域的小管密度呈放射状降低从哈佛运河到水泥线
Osteocytes interconnect with each other forming an intricate cell network within the mineralized bone matrix. One important function of the osteocyte network is the mechano-regulation of bone remodeling, where a possible mechanism includes the fluid flow through the porosity housing the cell network - the osteocyte lacuno-canalicular network (OLCN). In our study the OLCN in human osteons was three-dimensionally imaged with the aim to obtain a quantitative description of the canalicular density and spatial variations of this quantity within osteons. The topology of the OLCN was determined by first staining the bone samples with rhodamine, then imaging the OLCN with confocal laser scanning microscopy and finally using image analysis to obtain a skeletonized version of the network for further analysis. In total 49 osteons were studied from the femoral cortical bone of four different middle-aged healthy women. The mean canalicular density given as length of the canaliculi in a unit volume was 0.074 ± 0.015 μm/μm3 (corresponding to 74 km/cm3). No correlation was found between the canalicular density and neither the size of the osteon nor the volume fraction occupied by osteocyte lacunae. Within osteons the canalicular density varied substantially with larger regions without any network. On average the canalicular density decreases when moving from the Haversian canal outwards towards the cement line. We hypothesize that a decrease in accessible canaliculi with tissue age as a result of micropetrosis can reduce the local mechanosensitivity of the bone. Systematic future studies on age- and disease-related changes on the topology of the OLCN have to demonstrate the diagnostic potential of the presented characterization method. accurate three-dimensional representation of the canalicular network topology using confocal microscopy and image analysis quantitative network description with an average canalicular density of 74 km per cubic centimeter in healthy human osteons substantial variability of the canalicular density within osteons with 10% of the bone having a density twice the average in osteons large regions lacking an accessible network were found radial decrease of the canalicular density from the Haversian canal towards the cement line