Department of Oral and Maxillofacial Surgery, School & Hospital of Stomatology, Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China.
Department of Oral and Maxillofacial Surgery, School & Hospital of Stomatology, Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China.
Arch Oral Biol. 2021 Feb;122:105023. doi: 10.1016/j.archoralbio.2020.105023. Epub 2020 Dec 8.
This study aimed to explore the expression of hypoxia-inducible factor 1α (HIF-1α) in chondrocytes with the healing process after unilateral mandibular condylar neck osteotomy and to verify its effect on bone repair.
Models of mandibular condylar neck osteotomy were established in mice. Transgenic mice with heterozygous deficiency in HIF-1α gene in chondrocytes were used. Radiographic evaluation, quantitative reverse transcription polymerase chain reaction and histomorphometric analyses were used to compare the difference in capacities of chondrogenesis, vasifaction, osteogenesis, and bone resorption.
HIF-1α was expressed in the chondrocytes of calluses. Decreased expression of HIF-1α in chondrocytes promoted the proliferation of chondrocytes and upregulated the expression of apoptosis markers. However, the density and thickness of newly formed trabecula in transgenic mice were reduced on post-osteotomy day 28, and some expression of angiogenic, osteogenic, and osteoclastogenic markers was impaired.
These results demonstrated the importance of HIF-1α to chondrocytes and bone repair during the healing process after osteotomy of the mandibular condylar neck. Decreased HIF-1α promoted the chondrocyte proliferation, and effected endochondral ossification.
本研究旨在探讨缺氧诱导因子 1α（HIF-1α）在单侧下颌骨髁突颈骨折愈合过程中软骨细胞中的表达，并验证其对骨修复的影响。
建立了小鼠下颌骨髁突颈骨折模型。使用软骨细胞中 HIF-1α 基因杂合缺失的转基因小鼠。通过影像学评估、定量逆转录聚合酶链反应和组织形态计量学分析，比较软骨形成、血管生成、成骨和骨吸收能力的差异。
HIF-1α在骨痂的软骨细胞中表达。软骨细胞中 HIF-1α 的表达减少促进了软骨细胞的增殖，并上调了凋亡标志物的表达。然而，在术后第 28 天，转基因小鼠新形成的骨小梁的密度和厚度降低，一些血管生成、成骨和破骨标志物的表达受损。
这些结果表明 HIF-1α 在髁突颈骨折愈合过程中对软骨细胞和骨修复的重要性。HIF-1α 的减少促进了软骨细胞的增殖，并影响了软骨内成骨。
