Abstract:

Objective    Cathepsin B（CatB）belongs to the family of lysosomal cysteine proteases and plays an important role in the progression of many chronic inflammatory diseases. The objective of the research is to study the relationships among the expression of CatB，autophagy and inflammation in both human monocyte cell line（THP-1）infected by Porphyromonas gingivalis（P.g）and peri-implantitis gingival tissue. Methods    P.g infected THP-1 cell line was treated with CatB inhibitor （CA-074Me），and the expression of CatB，autophagy-associated proteins Beclin-1，tumor necrosis factor-α（TNF-α） and interleukin-1β（IL-1β） before and after CA-074Me treatment was compared by Western blot analysis. Collect healthy gingival tissue from volunteers and peri-implantitis gingival tissue from patients；frozen sections were made for immunofluorescent staining；protein was extracted to detect the expression of CatB；Beclin-1 and TNF-α by Western blot analysis. Results    The expression of CatB，Beclin-1，TNF-α and IL-1β in THP-1 infected by P.g was increased，and was decreased after being processed with CatB inhibitor. The level of CatB，Beclin-1 and TNF-α in peri-implantitis gingival tissue was significantly higher than that of healthy gingival tissue. Conclusion　The expression of CatB increases in both P.g-infected human monocyte cells and peri-implantitis gingival tissue，which is associated with autophagy and the secretion of inflammatory factors.

Key words: peri-implantitis；Cathepsin B；Beclin-1；TNF-&alpha, ；IL-1&beta

摘要：

目的    组织蛋白酶B（Cathepsin B，CatB）是一种能在许多慢性炎症进展中发挥重要作用的溶酶体半胱氨酸蛋白酶，本研究旨在观察牙龈卟啉单胞菌（Porphyromonas gingivalis，P.g）感染后的人单核细胞系THP-1中和种植体周围炎患者的牙龈组织中CatB表达量与炎症及自噬的关系。方法    P.g感染人单核细胞系THP-1细胞后，用CatB抑制剂CA-074Me处理THP-1细胞，Western blot对比CA-074Me处理前后CatB、自噬相关蛋白Beclin-1、肿瘤坏死因子-α（tumor necrosis factor -α，TNF-α）和白介素-1β（interleukin-1β，IL-1β）的表达情况。取志愿者正常牙龈组织和种植体周围炎患者的牙龈组织，分别制作冰冻切片后对CatB、Beclin-1和TNF-α进行免疫荧光染色，并提取蛋白采用Western blot检测CatB、Beclin-1和TNF-α在牙龈组织中的表达情况。结果    经P.g感染的THP-1细胞中CatB、Beclin-1、TNF-α和IL-1β的表达量均增高，且这些指标在CatB抑制剂的作用下降低；种植体周围炎患者的牙龈组织中，CatB、Beclin-1和TNF-α的表达量均明显高于正常牙龈组织。结论    P.g感染的人单核细胞和种植体周围炎患者牙龈组织中CatB的表达增高，且这一变化与自噬及促炎因子的分泌相关。

关键词: 种植体周围炎, 组织蛋白酶B, CatB, Beclin-1, 肿瘤坏死因子-&alpha, TNF-&alpha, 白介素-1&beta, IL-1&beta