Rehabilitation Medicine CenterWest China Hospital, Sichuan University, Chengdu, China.
Rehabilitation Key Laboratory of Sichuan ProvinceWest China Hospital, Sichuan University, Chengdu, China.
J Mol Endocrinol. 2018 Apr;60(3):185-198. doi: 10.1530/JME-17-0218. Epub 2018 Jan 16.
We examined the effects of tumor necrosis factor-α (TNFα) and interleukin-6 (IL6) gene knockout in preserving the bone loss induced by ovariectomy (OVX) and the mechanisms involved in bone metabolism. Twenty female wild-type (WT), -knockout (TNFα) or knockout (IL6) mice aged 12 weeks were sham-operated (SHAM) or subjected to OVX and killed after 4 weeks. Bone mass and skeletal microarchitecture were determined using micro-CT. Bone marrow stromal cells (BMSCs) from all three groups (WT, TNFα and IL6) were induced to differentiate into osteoblasts or osteoclasts and treated with 17-β-estradiol. Bone metabolism was assessed by histological analysis, serum analyses and qRT-PCR. OVX successfully induced a high turnover in all mice, but a repair effect was observed in TNFα and IL6 mice. The ratio of femoral trabecular bone volume to tissue volume, trabecular number and trabecular thickness were significantly decreased in WT mice subjected to OVX, but increased in TNFα mice (1.62, 1.34, 0.27-fold respectively; < 0.01) and IL6 mice (1.34, 0.80, 0.22-fold respectively; < 0.01). Furthermore, we observed a 29.6% increase in the trabecular number in TNFα mice when compared to the IL6 mice. Both, TNFα and IL6 BMSCs exhibited decreased numbers of TRAP-positive cells and an increase in ALP-positive cells, with or without E2 treatment ( < 0.05). While the knockout of or significantly upregulated mRNA expressions of osteoblast-related genes ( and ) and downregulated osteoclast-related mRNA for , and and , knockout appeared to have roles beyond knockout in upregulating mRNA expression and downregulating mRNA expressions of WNT-related genes ( and ) and TNF-related activation-induced genes (). TNFα seemed to be more potentially invasive in inhibiting bone formation and enhancing TRAF6-mediated osteoclastogenesis than IL6, implying that the regulatory mechanisms of TNFα and IL6 in bone metabolism may be different.
我们研究了肿瘤坏死因子-α（TNFα）和白细胞介素-6（IL6）基因敲除对卵巢切除（OVX）诱导的骨丢失的影响，以及涉及骨代谢的机制。20 只 12 周龄的野生型（WT）、TNFα 敲除（TNFα）或 IL6 敲除（IL6）雌性小鼠接受假手术（SHAM）或 OVX 处理，并在 4 周后处死。使用微 CT 测定骨量和骨骼微结构。从所有三组（WT、TNFα 和 IL6）的骨髓基质细胞（BMSCs）诱导分化为成骨细胞或破骨细胞，并与 17-β-雌二醇一起处理。通过组织学分析、血清分析和 qRT-PCR 评估骨代谢。OVX 成功地诱导了所有小鼠的高转化率，但在 TNFα 和 IL6 小鼠中观察到修复作用。WT 小鼠 OVX 后股骨小梁骨体积与组织体积比、小梁数和小梁厚度显著降低，但 TNFα 小鼠（分别为 1.62、1.34、0.27 倍； < 0.01）和 IL6 小鼠（分别为 1.34、0.80、0.22 倍； < 0.01）增加。此外，与 IL6 小鼠相比，TNFα 小鼠的小梁数增加了 29.6%。TNFα 和 IL6 BMSCs 均表现出 TRAP 阳性细胞数量减少和 ALP 阳性细胞数量增加，无论是否用 E2 处理（ < 0.05）。虽然 或 敲除显著上调了成骨相关基因（ 和 ）的 mRNA 表达，下调了破骨相关基因的 mRNA 表达（ 、 和 ），但 敲除似乎在上调 mRNA 表达和下调 WNT 相关基因（ 和 ）和 TNF 相关激活诱导基因（）的 mRNA 表达方面发挥了作用。TNFα 似乎比 IL6 更能抑制骨形成和增强 TRAF6 介导的破骨细胞生成，这表明 TNFα 和 IL6 在骨代谢中的调节机制可能不同。
