Effect of aging on microRNAs and regulation of pathogen recognition receptors

• Short non-coding microRNAs regulate gene expression and immune responses.
• Dysregulation of pathogen recognition receptors and responses occurs in aging.
• MiRNAs that modulate immune functions can change during aging.
• Aging-associated miRNAs target pro-inflammatory networks such as NF-κB.
• Aging-associated miRNAs could be therapeutic targets in immunosensecence.

Immunosenescence is the multifactorial age-associated immune deteriorization that leads to increased susceptibility to infections and decreased responses to vaccines. Recent studies have shown a fundamental role for microRNAs (miRNAs) in regulating immune responses, and nearly all the miRNAs involved in immune regulation show modulation during aging. Aging-associated miRNAs are largely negative regulators of the immune innate response and target central nodes of aging-associated networks, in particular, NF-κB, the downstream effector of TLR signals that leads to induction of proinflammatory responses. Multiple miRNAs have been reported to share similar regulatory activity. Here we review miRNA regulation of human innate immune recognition in aging, including both activation and resolution of inflammation, critical issues in detection, and areas of active investigation into our understanding of immunosenescence.