Palmier Mathilde, Maître Marlène, Doat Hélène, Lesté-Lasserre Thierry, Boiziau Claudine, Maurel Delphine B
Inserm, University of Bordeaux, BioTis Laboratory UMR 1026, Bordeaux 33000, France.
Inserm, University of Bordeaux, Neurocentre Magendie UMR 1215, Bordeaux 33000, France.
Aging (Albany NY). 2025 Aug 22;17(8):2089-2112. doi: 10.18632/aging.206302.
While blood vessels and osteocytes have been studied independently, their simultaneous changes with age remain undescribed. Our objective was to investigate the age-related evolution of both osteocyte and blood vessel networks in mouse cortical bone, and to assess the associated effects on osteocyte markers and oxygen intracellular levels. We analyzed femurs of male Flk1-GFP mice from growing, mature, middle-aged, and aged groups with techniques such as laser microdissection followed by RT-qPCR, tissue clearing and 3D fluorescence imaging. In the mature animals - when the cortical bone was thicker than in the growing animals - the osteocyte density, the number of dendrites per osteocyte and the blood vessel density were lower. This was associated with a reduced expression of and with a smaller fraction of osteocytes exhibiting low intracellular oxygen. In aged animals - when cortical bone was thinner than in mature animals - the number of dendrites per osteocyte and the blood vessel density were lower. This was associated with a reduced (Cx43) expression. Our results suggest that changes in the osteocyte network during maturation and aging are led by distinct mechanisms, and that the cortical bone blood vessels are not the main source of oxygen for osteocytes.
虽然血管和骨细胞已被分别研究，但它们随年龄的同步变化仍未得到描述。我们的目的是研究小鼠皮质骨中骨细胞和血管网络的年龄相关演变，并评估其对骨细胞标志物和细胞内氧水平的相关影响。我们使用激光显微切割后进行RT-qPCR、组织透明化和3D荧光成像等技术，分析了生长、成熟、中年和老年组雄性Flk1-GFP小鼠的股骨。在成熟动物中——此时皮质骨比生长动物中的更厚——骨细胞密度、每个骨细胞的树突数量和血管密度较低。这与Runx2表达降低以及显示低细胞内氧的骨细胞比例较小有关。在老年动物中——此时皮质骨比成熟动物中的更薄——每个骨细胞的树突数量和血管密度较低。这与Cx43表达降低有关。我们的结果表明，成熟和衰老过程中骨细胞网络的变化由不同机制主导，并且皮质骨血管不是骨细胞的主要氧来源。
