Macrophage Erythroblast Attacher Gene Polymorphismand Periodontitis in Postmenopausal Women

Objectives: Macrophage erythroblast attacher (MAEA) plays an important role in the development of mature macrophages by mediating the attachment of erythroblasts to macrophage. Recent reports demonstrated that MAEA gene polymorphism was associated with type 2 diabetes in East Asians. The role of MAEA in inflammatory diseases remains unclear. In the present study, we explored the possible relationship between MAEA and periodontitis in a case-control study and in vitro experiments with THP-1 derived macrophages.
Methods: The final sample comprised 345 postmenopausal Japanese women lived in Yokogoshi area, Niigata City. Clinical attachment levels (CAL) were measured per tooth. Genomic DNA was extracted from peripheral blood. A SNP in MAEA (rs6815464) was analyzed with the TaqMan method. Biochemical values of blood, including hemoglobin A1c (HbA1c), high-sensitivity C-reactive protein (hsCRP), serum type I collagen crosslinked N-telopeptides (NTX) and albumin were evaluated. In vitro study, THP-1 derived macrophages were stimulated with LPS from Porphyromonas gingivalis (P. gingivalis) for 12hours, and MAEA expression levels were measured with RT-qPCR and western blot analysis.
Results: No significant difference in age, number of teeth, smoking, HbA1c, presence of diabetes, or hsCRP was found between the genotypes. The mean CAL was significantly higher in the G allele carrier group than in the non-carrier group. Controlled with age as a covariate, positive correlations were found between mean CAL and NTX levels, and between mean CAL and albumin in the G carrier group. Stimulation with P. gingivalis LPS (0.1~1μg/ml) decreased MAEA mRNA and protein in macrophages.
Conclusions: MAEA gene polymorphism was associated with periodontitis but not with diabetes. Periodontitis was correlated with NTX and albumin in the G allele carriers. P. gingivalis LPS down-regulated MAEA expression in THP-1 derived macrophages.