Faculty of Dentistry, McGill University, Montreal, QC, Canada.
Faculty of Dentistry, McGill University, Montreal, QC, Canada; Senior specialist in periodontology, Royal Medical Services, Amman, Jordan.
Injury. 2021 Jul;52(7):1697-1708. doi: 10.1016/j.injury.2021.05.001. Epub 2021 May 9.
Age-related changes in blood composition have been found to affect overall health. Thus, this study aimed to understand the effect of these changes on bone healing by assessing how plasma derived from young and old rats affect bone healing using a rat model.
. Blood plasma was collected from 6-month and 24-month old rats. Differences in elemental composition and metabolome were assessed using optical emission spectrometry and liquid mass spectrometry, respectively. Bilateral tibial bone defects were created in eight rats. Young plasma was randomly applied to one defect, while aged plasma was applied to the contralateral one. Rats were euthanized after two weeks, and their tibiae were analyzed using micro-CT and histology. The proteome of bone marrow was analyzed in an additional group of three rats.
Bone-defects treated with aged-plasma were significantly bigger in size and presented lower bone volume/tissue volume compared to defects treated with young-plasma. Histomorphometric analysis showed fewer mast cells, macrophages, and lymphocytes in defects treated with old versus young plasma. The proteome analysis showed that young plasma upregulated pathways required for bone healing (e.g. RUNX2, platelet signaling, and crosslinking of collagen fibrils) whereas old plasma upregulated pathways, involved in disease and inflammation (e.g. IL-7, IL-15, IL-20, and GM-CSF signaling). Plasma derived from old rats presented higher concentrations of iron, phosphorous, and nucleotide metabolites as well as lower concentrations of platelets, citric acid cycle, and pentose phosphate pathway metabolites compared to plasma derived from young rats.
bone defects treated with plasma-derived from young rats showed better healing compared to defects treated with plasma-derived from old rats. The application of young and old plasmas has different effects on the proteome of bone defects.
血液成分的年龄相关性变化已被发现会影响整体健康。因此，本研究旨在通过评估来自年轻和老年大鼠的血浆对大鼠模型中骨愈合的影响来了解这些变化对骨愈合的影响。
从 6 月龄和 24 月龄大鼠中采集血浆。分别使用原子发射光谱法和液相质谱法评估元素组成和代谢组的差异。在 8 只大鼠的双侧胫骨骨缺损处。将年轻的血浆随机应用于一个缺陷，而将老年的血浆应用于对侧。两周后处死大鼠，用 micro-CT 和组织学分析其胫骨。另外 3 只大鼠的骨髓蛋白质组也进行了分析。
用老年血浆处理的骨缺陷在大小上明显更大，并且与用年轻血浆处理的骨缺陷相比，骨体积/组织体积较低。组织形态计量学分析显示，与用年轻血浆处理的骨缺陷相比，用老年血浆处理的骨缺陷中的肥大细胞、巨噬细胞和淋巴细胞较少。蛋白质组分析表明，年轻血浆上调了骨愈合所需的途径（例如 RUNX2、血小板信号转导和胶原纤维的交联），而老年血浆上调了与疾病和炎症相关的途径（例如 IL-7、IL-15、IL-20 和 GM-CSF 信号转导）。与年轻大鼠的血浆相比，老年大鼠的血浆中含有更高浓度的铁、磷和核苷酸代谢物，以及较低浓度的血小板、柠檬酸循环和戊糖磷酸途径代谢物。
与用老年大鼠血浆处理的骨缺陷相比，用年轻大鼠血浆处理的骨缺陷的愈合更好。年轻和老年血浆的应用对骨缺陷的蛋白质组有不同的影响。
