Staphylococcal enterotoxin C2 promotes

osteogenesis of mesenchymal stem cells

and accelerates fracture healing

Objectives

As one of the heat-stable enterotoxins, Staphylococcal enterotoxin C2 (SEC2) is synthesized

by Staphylococcus aureus, which has been proved to inhibit the growth of tumour cells, and

is used as an antitumour agent in cancer immunotherapy. Although SEC2 has been reported

to promote osteogenic differentiation of human mesenchymal stem cells (MSCs), the in vivo

function of SCE2 in animal model remains elusive. The aim of this study was to further elucidate

the in vivo effect of SCE2 on fracture healing.

Materials and Methods

Rat MSCs were used to test the effects of SEC2 on their proliferation and osteogenic differentiation

potentials. A rat femoral fracture model was used to examine the effect of local

administration of SEC2 on fracture healing using radiographic analyses, micro-CT analyses,

biomechanical testing, and histological analyses.

Results

While SEC2 was found to have no effect on rat MSCs proliferation, it promoted the osteoblast

differentiation of rat MSCs. In the rat femoral fracture model, the local administration of

SEC2 accelerated fracture healing by increasing fracture callus volumes, bone volume over

total volume (BV/TV), and biomechanical recovery. The SEC2 treatment group has superior

histological appearance compared with the control group.

Conclusion

These data suggest that local administration of SEC2 may be a novel therapeutic approach

to enhancing bone repair such as fracture healing.

Cite this article: Bone Joint Res 2018;7:179–186.

骨与关节研究杂志   2018年

金葡菌肠毒素C2促进间充质干细胞的成骨分化及加速骨折愈合的研究

香港中文大学 李刚

目的：作为一种热稳定性的肠毒素，由金葡菌合成的金葡菌肠毒素C2（SEC2）可抑制肿瘤细胞的生长并作为抗肿瘤药物用于肿瘤的免疫治疗。尽管有研究表明SEC2可促进人间充质干细胞（MSCS）的成骨分化，但SEC2在动物模型体内的作用尚不明确。本研究的目的是进一步阐明SEC2对骨折愈合的体内作用。

材料和方法：采用大鼠间充质干细胞考察SEC2对其增殖和成骨分化能力的影响。建立大鼠股骨骨折模型，通过影像学分析、微型CT、生物力学测试和组织学分析的方法考察SEC2局部给药对骨折愈合的作用。

结果：尽管SEC2对大鼠间充质干细胞的增殖没有影响，但可促进其成骨细胞分化。对于大鼠股骨骨折模型，SEC2局部给药后通过增加骨痂体积、骨体积分数（BV/TV）和生物力学恢复来加速骨折愈合。与对照组相比，SEC2治疗组有更好的组织结构。

结论：SEC2局部给药是促进骨修复如骨折愈合的一种新疗法。

Staphylococcal enterotoxin C2 promotes  osteogenesis of mesenchymal stem cells  and accelerates fracture healing.pdf