Relationships of BTB/POZ domain-containing protein 7 and matrix metalloproteinase-9 expression with autoantibodies in labial gland tissues of patients with primary Sjögren's syndrome

Objective To investigate the relationships of BTB/POZ domain-containing protein 7 (BTBD7) and matrix metalloproteinase-9 (MMP-9) expression with autoantibodies in labial gland tissues of patients with primary SjÖgren′s syndrome (pSS).

Methods From September 2016 to October 2020, the labial gland tissues of 46 patients with pSS were collected as pSS group, and the labial gland tissues of 46 patients with xerostomia in the same period were collected as control group. The mRNA and protein expressions of BTBD7 and MMP-9 in labial gland tissues were detected; the relationships of the serum autoantibodies anti-SjÖgren′s syndrome antigen A (SSA) antibody, anti-SjÖgren′s syndrome antigen B (SSB) antibody, and antinuclear antibody (ANA) with BTBD7 and MMP-9 were analyzed in patients with pSS; the correlation between protein expression level of BTBD7 and protein expression level of MMP-9 was analyzed.

Results Compared with the control group, the mRNA and protein expression levels of BTBD7 and MMP-9 in the labial gland tissues of patients in the pSS group were significantly higher (P < 0.05). In the detection results of anti-SSA antibody, anti-SSB antibody and ANA antibody in the patients with pSS, the mRNA and protein expression levels of BTBD7 and MMP-9 in the labial gland tissues of positive patients were significantly higher than those of negative patients (P < 0.05). The correlation analysis showed that there was a significant positive correlation between protein expression level of BTBD7 and protein expression level of MMP-9 in the labial gland tissues of patients with pSS (r=0.493, P < 0.05).

Conclusion BTBD7 and MMP-9 are highly expressed in the labial gland tissues of patients with pSS, and are closely related to the expressions of autoantibodies such as anti-SSA antibody, anti-SSB antibody and ANA.