Department of Regenerative Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, 700-8558, Japan; Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, 700-8558, Japan.
Department of Regenerative Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, 700-8558, Japan.
Biochem Biophys Res Commun. 2019 Sep 3;516(4):1229-1233. doi: 10.1016/j.bbrc.2019.07.014. Epub 2019 Jul 9.
Global gene deletion studies have established that Runt-related transcription factor-2 (Runx2) is essential during skeletogenesis for osteoblastic differentiation in both intramembranous and endochondral ossification processes. However, the postnatal significance of Runx2 in vivo is poorly understood because a global Runx2 deletion causes perinatal lethality. In this study, we generated tamoxifen-induced Runx2 global deficient mice by crossing Runx2 mice with ROSA26-CreER mice (Rosa26-CreER; Runx2). Four-week-old mice were intraperitoneally treated with tamoxifen for five consecutive days, sacrificed, and analyzed six weeks after tamoxifen administration. Deletion of Runx2 led to low bone mass, which is associated with decreased bone formation and bone resorption as well as excessive bone marrow adiposity. Collectively, postnatal Runx2 absolutely plays an important role in maintaining the homeostasis of bone tissues not only in bone mass, but also in the bone marrow environment.
全球基因缺失研究已经证实，Runt 相关转录因子 2（Runx2）在骨骼发生过程中对于成骨细胞分化是必不可少的，无论是在膜内成骨还是软骨内成骨过程中。然而，Runx2 在体内的出生后意义尚不清楚，因为全局 Runx2 缺失会导致围产期致死。在这项研究中，我们通过将 Runx2 小鼠与 ROSA26-CreER 小鼠（Rosa26-CreER；Runx2）杂交，生成了他莫昔芬诱导的 Runx2 全局缺失小鼠。4 周龄的小鼠经腹腔注射他莫昔芬连续 5 天，给药 6 周后处死并进行分析。Runx2 的缺失导致骨量减少，这与骨形成和骨吸收减少以及骨髓脂肪过多有关。总之，出生后 Runx2 绝对在维持骨组织的内稳态方面发挥着重要作用，不仅在骨量方面，而且在骨髓环境方面也是如此。
