Sonic Hedgehog信号通路在大鼠牙髓炎中的作用

Role of Sonic Hedgehog Signaling Pathway in Rat Inflammatory Dental Pulp

目的:观察Sonic Hedgehog(Shh)信号分子在大鼠牙髓炎中的免疫定位,探讨Shh信号通路在牙髓防御和修复中所起的作用。方法:将15只SD大鼠随机分成1d、3d和7d组,每组5只,用穿髓开放法建立大鼠牙髓炎模型,3组大鼠分别于术后1,3,7d处死,取出下颌磨牙,常规组织学处理,免疫组化方法检测Shh,Smo,Ptc,Gli1的表达,并对Shh信号通路在大鼠牙髓炎中的表达进行半定量分析,对照组为大鼠正常牙髓。结果:大鼠牙髓炎模型1,3,7dShh广泛表达于穿髓孔下方牙髓间充质细胞及远离穿髓孔的根髓细胞中,表达量随炎症的进展无显著性提高(P>0.05)。Ptc、Smo、Gli1在大鼠牙髓损伤后1d未见阳性表达,3d和7d均表达于穿髓孔下方牙髓间充质细胞中,且表达量均有显著性提高(P<0.05)。空白对照组中Shh信号通路阴性表达。结论:Shh信号通路在牙髓炎过程中表达,提示其可能被激活,参与牙髓炎症反应。

Objective： To immunolocalize the sonic Hedgehog （Shh） signaling pathway in rat inflamma- tory dental pulp, and to illustrate the potential roles of Shh signaling pathway in the defense function of dental pulp and the pulp repair process following trauma or infection. Methods： The pulp of first lower molars of fifteen normal rats were exposed and left open into oral cavity. Five animals of each group were sacrificed respectively on the 1st, 3st, and 7th days affter pulp expo- sure and paraffin sections were prepared through histological process. SP Method was used to im- munostain the localization and distribution of Shh, Patched（Ptc）, Smoothende（Smo） and Glioma l（Glil）. The immunostaining were assessed statistically. The normal rat pulps were set as con- trol group. Results. Shh generally immunolocalized in the dental pulp mesenchymal cells on 1, 3, and 7 days, not only around the exposed pulp but also in apical part of pulp which far from the exposed part. And Shh expression unchanged during observation time（P〉0.05）. On the 1st day of rat inflammatory dental pulp, Ptc, Smo and Glil is negative, but their expression increased significantly after 3 and 7 days （P〈O. 05）, and immunolocalized in the dental pulp mesenchymal cells around the exposed pulp. Shh signaling pathway in control group was negative. Conclusion. Shh signaling pathway is activated in inflammatory dental pulp, and it may be involved in pulpitis.