口腔医学研究

口腔医学研究 ›› 2024, Vol. 40 ›› Issue (8): 682-686.DOI: 10.13701/j.cnki.kqyxyj.2024.08.004

• 口腔生物学研究 • 上一篇    下一篇

骨细胞中敲除Setd2对小鼠骨量的影响

牛佳欣, 袁国华*   

  1. 口颌系统重建与再生全国重点实验室,口腔生物医学教育部重点实验室,口腔医学湖北省重点实验室,武汉大学口腔医学院 湖北 武汉 430079
  • 收稿日期:2024-01-15 出版日期:2024-08-28 发布日期:2024-08-22
  • 通讯作者: *袁国华,E-mail:yuanguohua@whu.edu.cn
  • 作者简介:牛佳欣(1998~ ),女,河南洛阳人,硕士在读,研究方向:牙齿与骨发育生物学。
  • 基金资助:
    国家自然科学基金(编号:82370913)

Impact of Setd2 Knockout in Osteocytes on Mouse Bone Mass

NIU Jiaxin, YUAN Guohua*   

  1. State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan 430079, China
  • Received:2024-01-15 Online:2024-08-28 Published:2024-08-22

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摘要： 目的: 明确骨细胞中的Setd2对小鼠骨量的调控作用。方法: 将Dmp1Cre与Setd2flox/flox小鼠配繁,构建在骨细胞中特异性敲除Setd2的小鼠(Setd2 cKO,Dmp1Cre;Setd2flox/flox)。采用免疫组织化学染色验证Setd2特异性敲除后,对成长至6月龄的同窝小鼠骨组织进行显微CT扫描。将CT进行三维重建,观察对照小鼠与Setd2 cKO小鼠鼠的皮质骨及松质骨骨量变化。利用骨形态学分析软件分析皮质骨及松质骨骨量变化,骨小梁数量、厚度及分离度等差异。利用番红O固绿染色观察Setd2 cKO小鼠与对照小鼠中呈蓝色的骨组织区域的变化。采用免疫组织化学染色观察Setd2特异性敲除后对组蛋白H3第36位赖氨酸位点的三甲基化修饰(trimethylation of lysine 36 on histone 3,H3K36me3)的影响。结果: 免疫组织化学染色结果显示Setd2在骨细胞中被成功敲除,Setd2 cKO小鼠体型小于同窝对照小鼠,显微CT及骨形态学分析结果显示,6月龄时,与对照组小鼠相比,Setd2 cKO小鼠的皮质骨变薄,骨密度降低,骨小梁厚度减小,骨小梁数量减少,骨小梁分离度增加(P<0.05)。利用番红O固绿染色观察Setd2 cKO小鼠呈蓝色的骨组织区域比对照小鼠少,免疫组织化学染色结果显示与对照组小鼠相比,Setd2 cKO小鼠的H3K36me3的修饰出现缺失。结论: 骨细胞中Setd2的缺失影响骨细胞的H3K36位点的三甲基化修饰,从而导致小鼠骨量减少。

关键词: Setd2, 基因敲除, 骨细胞, 骨量

Abstract: Objective: To elucidate the regulatory impact of Setd2 within osteocytes on bone formation. Methods: Setd2flox/flox mice were crossed with the Dmp1Cre strain to generate Dmp1Cre, Setd2flox/flox mice. All mice analyzed were maintained on the C57BL/6 background. Immunohistochemical staining was used to confirm the specific deletion of Setd2 in osteocytes. Micro-CT and three-dimensional reconstruction were used to analyze cortical and trabecular bone mass variations in bone tissues from same-litter mice at 6 months of age. Differences in bone morphology parameters, such as trabecular number, thickness, and separation, were conducted using CTAn software. Additionally, safranine O/fast green staining was utilized to observe changes in the blue-stained bone tissue regions in Setd2 cKO and control mice. Immunohistochemical staining was used to observe trimethylation of lysine 36 on histone 3 (H3K36me3). Results: With successful Setd2 deletion in osteocytes, Setd2 cKO mice exhibited smaller body size compared to littermate controls. Micro-CT and bone morphometry analysis revealed that, at 6 months of age, Setd2 cKO mice displayed thinner cortical bone, decreased bone density, reduced trabecular thickness, lower trabecular number, and increased trabecular separation compared to control mice (P<0.05). Safranine O/fast green staining further indicated a reduced blue-stained bone tissue area in Setd2 cKO mice compared to controls. Compared to the control group mice, there was a loss of H3K36me3 modification in Setd2 cKO mice. Conclusion: The loss of Setd2 in osteocytes affected the trimethylation modification of H3K36, resulting in a decrease in mouse bone mass.

Key words: Setd2, gene knockout, osteocytes, bone mass