Age-dependent messenger RNA expression of toll-like receptor 4 and intercellular adhesion molecule-1 in peripheral
Chiung-Jung Wen1,2, Chin-Hao Chang3, Chin-Ying Chen2,4
1Department of Geriatrics and Gerontology, National Taiwan University Hospital, Taipei, Taiwan.
Background:
Inflammation plays an important role in the ageing process in which monocytes/macrophages are important players. Intercellular adhesion molecule-1 (ICAM-1), tumour necrosis factor-α (TNF-α) and Toll-like receptor 4 (TLR4) are well-known inflammatory markers. This study aimed 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:
A total of 239 participants were recruited in a medical centre 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 < .0001). Also, both age and TLR4 were independent factors affecting mononuclear cell ICAM-1 in the multiple linear regression analysis (P < .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 ageing process.
Insights
Older adults exhibit higher levels of inflammatory markers Intercellular Adhesion Molecule-1 (ICAM-1) and Toll-Like Receptor 4 (TLR4) in peripheral blood mononuclear cells (PBMCs). TLR4 independently influences ICAM-1 expression, suggesting their role in the aging process.
Area of Science:
- Gerontology and Aging Research
- Immunology and Inflammation Studies
- Molecular Biology and Gene Expression
Background:
- Inflammation is a key component of the aging process, with monocytes/macrophages playing significant roles.
- Key inflammatory markers include Intercellular Adhesion Molecule-1 (ICAM-1), Tumor Necrosis Factor-alpha (TNF-α), and Toll-Like Receptor 4 (TLR4).
Purpose of the Study:
- To investigate the relationship between chronological age and the expression of ICAM-1, TNF-α, and TLR4 mRNA in peripheral blood mononuclear cells (PBMCs).
- To explore the correlation between these inflammatory markers in different age groups.
Main Methods:
- Recruitment of 239 participants in Taiwan, categorized into younger (<65 years) and older (≥65 years) adults.
- Quantification of ICAM-1, TNF-α, and TLR4 mRNA levels in PBMCs using real-time polymerase chain reaction (PCR).
- Application of propensity-matched analysis for robust subgroup comparisons.
Main Results:
- Significantly higher mRNA levels of ICAM-1, TNF-α, and TLR4 were observed in older adults compared to younger adults (P < .0001 for all).
- Multiple linear regression analysis identified both age and TLR4 as independent factors influencing ICAM-1 expression in mononuclear cells (P < .0001).
Conclusions:
- Elevated mRNA levels of ICAM-1 and TLR4 in PBMCs are characteristic of older adults.
- TLR4 acts as an independent determinant of ICAM-1 expression, particularly in the elderly population.
- ICAM-1 and TLR4 in PBMCs show potential as biomarkers for the aging process.
