Takeno Ayumu, Kanazawa Ippei, Tanaka Ken-Ichiro, Notsu Masakazu, Kanasaki Keizo, Oono Takamasa, Ogawa Yoshihiro, Sugimoto Toshitsugu
Internal Medicine 1, Shimane University Faculty of Medicine, 89-1, Enya-cho, Izumo, Shimane 693-8501 Japan.
Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka, 812-8582 Japan.
Diabetol Int. 2020 Aug 30;12(2):171-180. doi: 10.1007/s13340-020-00463-5. eCollection 2021 Apr.
Diabetes mellitus is associated with bone fragility. Although osteoblast maturation is disturbed in patients with diabetes mellitus, the involvement of high glucose (HG) in different stages of osteoblast maturation is unclear. We used MC3T3-E1 cells, a murine osteoblastic cell line. The cells were incubated in high glucose medium (16.5 and 27.5 mM) with three different time courses: throughout 21 days, only first 7 days (early stage) and only last 7 days (late stage). Mineralization assay showed that HG throughout 21 days increased mineralization compared with control (5.5 mM). In the time course experiment, HG increased mRNA expression of , osteocalcin (), runt-related transcription factor 2 and osterix on days 3 and 5. By contrast, long-term treatment with HG (14 and 21 days) decreased expression of these osteoblastic markers. HG only during early stage enhanced mineralization, while HG only during late stage had no effects. HG increased the expression of bone morphogenetic protein (BMP) 4 and enhanced phosphorylation of Smad1/5/8. Treatment with a BMP receptor antagonist LDN193189 prevented the HG-induced mineralization during early stage of osteoblast differentiation, indicating that HG in the early stage promotes mineralization by BMP4. In conclusion, the study demonstrates that continuous HG treatment might enhance early osteoblast differentiation but disturbs osteoblast maturation, and that BMP-4-Smad signal might be involved in the HG-induced differentiation and mineralization of osteoblasts.
糖尿病与骨脆性相关。尽管糖尿病患者的成骨细胞成熟受到干扰，但高糖（HG）在成骨细胞成熟不同阶段的作用尚不清楚。我们使用了小鼠成骨细胞系MC3T3-E1细胞。将细胞在高糖培养基（16.5和27.5 mM）中培养，设置三个不同的时间进程：整个21天、仅前7天（早期）和仅后7天（晚期）。矿化分析表明，与对照（5.5 mM）相比，21天全程的HG增加了矿化。在时间进程实验中，HG在第3天和第5天增加了骨钙素（）、 runt相关转录因子2和osterix的mRNA表达。相比之下，HG长期处理（14天和21天）降低了这些成骨细胞标志物的表达。仅在早期的HG增强了矿化，而仅在晚期的HG没有作用。HG增加了骨形态发生蛋白（BMP）4的表达并增强了Smad1/5/8的磷酸化。用BMP受体拮抗剂LDN193189处理可阻止HG诱导的成骨细胞分化早期的矿化，表明早期的HG通过BMP4促进矿化。总之，该研究表明持续的HG处理可能增强早期成骨细胞分化，但会干扰成骨细胞成熟，并且BMP-4-Smad信号可能参与HG诱导的成骨细胞分化和矿化。
