BACKGROUND: Inflammation plays an important role in the aging process in which monocytes/macrophages are important players. Intercellular adhesion molecule-1 (ICAM-1), tumor necrosis factor-α (TNF-α) and Toll-like receptor 4 (TLR4) are well known inflammatory markers. This study aims to investigate the relationship between age and the expression and correlation of ICAM-1, TNF-α and TLR4 mRNA in peripheral blood mononuclear cells (PBMCs). METHODS: Total 239 participants were recruited in a medical center in Taiwan. The mRNA isolated from the PBMCs was used to determine the levels of ICAM-1, TNF-α and TLR4 mRNAs with real-time polymerase chain reaction (PCR). The propensity matched analysis was also applied for subgroup analysis. RESULTS: When compared 189 older adults (≧ 65 years) to 50 younger adults (< 65 years), the ICAM-1, TNF-α, and TLR4 mRNA levels in PBMCs were significantly higher in older adults (2.00 ± 0.72 vs 0.87 ± 0.34 for ICAM-1, 2.32 ± 0.69 vs 1.15 ± 0.44 for TNF-α, and 1.56 ± 0.47 vs 1.05 ± 0.51 for TLR4, and all p < 0.0001). Also, both age and TLR4 were independent factors affecting mononuclear cell ICAM-1 in the multiple linear regression analysis (p < 0.0001). CONCLUSION: The mRNA levels of ICAM-1 and TLR4 in PBMCs are higher in older adults than those in younger adults. TLR4 is an independent factor affecting ICAM-1 expression in PBMCs, especially in older adults. This may suggest that ICAM-1 and TLR4 in PBMCs are potential biomarkers and their relationship may shed some light on the aging process.
Date:
2021-07
Relation:
European Journal of Clinical Investigation. 2021 Jul;51(7):Article number e13522.
