The effects of Porphyromonas gingivalis on MUC1 expression in gingival tissues

• Main Authors: Chin-Cheng Lee, 李晉成
• Other Authors: Yu-Lin Lai
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/299gqm

碩士 === 國立陽明大學 === 牙醫學系 === 106 === Periodontal disease is a bacteria-induced chronic inflammatory disease that leads to the destruction of the periodontium. Clinical signs include alveolar bone resorption, tooth mobility and tooth loss. Porphyromonas gingivalis, produces a variety of virulence factors, is one of the periodontal pathogens. MUC1, a glycoprotein, belongs to the family of tethered transmembrane mucins. MUC1 comprises an α subunit (extracellular domain) and a β subunit, composed of a transmembrane region and a cytoplasmic tail. MUC1 is expressed in epithelial tissues of conjunctivae, respiratory tracts, gastrointestinal tracts and urogenital tracts. In the oral cavity, mucosal epithelia, salivary glands, tonsil, tongue, larynx and pharynx are lined by MUC1. MUC1 has been demonstrated to be involved in infection of respiratory tracts and gastrointestinal tracts. Its α subunit can influence bacterial adherence to epithelium, while its β subunit is related to activation of cell signaling pathways, which may lead to modulation of bacterial infection. Little is known about the role of MUC1 in periodontal infection. This study aimed to determine the expression and the distribution of MUC1 in the gingival tissues, effects of P. gingivalis infection on MUC1 expression in gingival tissues and cells and the glycosylation profile in oral epithelial cells. In the present study, the expression of MUC1 in primary gingival keratinocytes (GK), immortalized normal oral keratinocytes (NOK), oral carcinoma cell line (OC3) and oral epidermoid carcinoma cell line (OEC-M1) and in NOK which were incubated with lipopolysaccharide (LPS) purified from P. gingivalis was examined using Western blotting analysis. The distribution and expression changes of MUC1 in gingiva tissues from human subjects or from rats infected orally with P. gingivalis were examined by immunohistochemistry. The sugar profiles in lysates from oral epithelial cells were examined with the lectin assay. The antibody, which recognized the α subunit of MUC1, detected MUC1 in OC3 cells, but not in GK and NOK. All three antibodies used for the α subunit recognized MUC1 proteins with different molecular weights in OEC-M1. The β subunit was shown to be expressed in GK, NOK, OC3 and OEC-M1 cells. The strongest signal of the β subunit was shown in OEC-M1 cells. The levels of the β subunit of MUC1 in NOK were increased by LPS in a does dependent manner. The results showed that α and β subunits of MUC1 were detected in gingival tissues. The stronger expression was observed in the prickle cell layer and the basal layer, while weak expression was shown in the keratinized cell layer and the granular cell layer. In connective tissues, almost no MUC1 was expressed. Moreover, the increased expression of MUC1 in nuclei in the basal layer and the prickle cell layer of gingiva from P. gingivalis-infected rats was observed. The results of the lectin assay showed the similarity and variations in profiles of sugar in lysates from different oral epithelial cells. These results suggested that MUC1 was expressed in epithelium of gingival tissues. P. gingivalis infection might increase MUC1 expression. Sugar profiles of MUC1 can be examined on the basis of our results in the future.