Endodontics, Comprehensive Dental Care, The University of Hong Kong, Hong Kong, China.
Dent Traumatol. 2013 Feb;29(1):59-65. doi: 10.1111/j.1600-9657.2012.01138.x. Epub 2012 Apr 9.
Hank's balanced salt solution (HBSS) and milk have gained wide acceptance as storage media for avulsed tooth. However, the effect of the media and storage time on the periodontal ligament (PDL) cells involvement in the development of root resorption is still unclear. The purpose of this study was to evaluate whether precultured PDL cells in HBSS, milk, or modified Eagle's medium alpha (α-MEM) would affect osteoclastogenesis.
PDL cells were precultured in HBSS, milk, or α-MEM for 1 h or 6 h before being co-cultured with RAW 264.7 cells for an additional 3 days for mRNA analysis and 11 days for osteoclastogenesis assay.
Cyclooxygenase-2 (COX-2) mRNA was detected immediately in PDL cells precultured in the three storage media. The expression was up-regulated markedly in all co-cultures when compared with RAW cells alone. As a result of the co-culture, interleukin-1β (IL-1β) expression was detectable in both PDL and RAW cells. TRAP+ multinucleated, osteoclast-like cells developed in all co-cultures; the number of TRAP+ cells was highest (P < 0.05) in the co-cultures that PDL cells precultured in milk for 6 h. The mRNA level of receptor activator of nuclear factor-kappa B ligand (RANKL) was not detected in PDL cells. Osteoprotegerin (OPG) mRNA expression reduced with increased preculture time, but the difference was not significant (P > 0.05).
PDL cells kept in the three storage media led to TRAP+ multinucleated, osteoclast-like cells formation via RANKL-independent signaling. The ability to induce osteoclastogenesis may be considered as one of the factors to evaluate the ability of storage medium to maintain PDL viability after tooth avulsion.
Hank 平衡盐溶液（HBSS）和牛奶已被广泛接受为外伤性牙齿的储存介质。然而，储存介质和储存时间对牙周韧带（PDL）细胞参与根吸收的影响尚不清楚。本研究旨在评估 HBSS、牛奶或改良 Eagle 培养基α（α-MEM）中预培养的 PDL 细胞是否会影响破骨细胞形成。
将 PDL 细胞分别在 HBSS、牛奶或α-MEM 中预培养 1 小时或 6 小时，然后与 RAW 264.7 细胞共培养 3 天进行 mRNA 分析和 11 天进行破骨细胞形成测定。
立即在三种储存介质中预培养的 PDL 细胞中检测到环氧化酶-2（COX-2）mRNA。与单独的 RAW 细胞相比，所有共培养物中的表达均明显上调。由于共培养，IL-1β（IL-1β）在 PDL 和 RAW 细胞中均有表达。在所有共培养物中均形成了 TRAP+多核、破骨细胞样细胞；在牛奶中预培养 6 小时的 PDL 细胞的共培养物中，TRAP+细胞数量最多（P<0.05）。在 PDL 细胞中未检测到核因子-κB 受体激活剂配体（RANKL）的 mRNA 表达。骨保护素（OPG）mRNA 表达随预培养时间的增加而减少，但差异无统计学意义（P>0.05）。
保存在三种储存介质中的 PDL 细胞通过 RANKL 非依赖性信号导致 TRAP+多核、破骨细胞样细胞形成。诱导破骨细胞形成的能力可被视为评估储存介质在牙外伤后维持 PDL 活力能力的因素之一。
