Inhibition of microRNA-155 Alleviates Cognitive Impairment in Alzheimer's Disease and Involvement of Neuroinflammation

Curr Alzheimer Res. 2019;16(6):473-482. doi: 10.2174/1567205016666190503145207.


Background: Neuroinflammation has important effects on cognitive functions in the pathophysiological process of Alzheimer's Disease (AD). In the current report, we determined the effects of microRNA-155 (miR-155) on the levels of IL-1β, IL-6 and TNF-α, and their respective receptors in the hippocampus using a rat model of AD.

Methods: Real-time RT-PCR, ELISA and western blot analysis were used to examine the miR-155, PICs and PIC receptors. The Morris water maze and spatial working memory tests were used to assess cognitive functions.

Results: miR-155 was increased in the hippocampus of AD rats, accompanied by amplification of IL-1β, IL-6 and TNF-α. Intracerebroventricular infusion of miR-155 inhibitor, but not its scramble attenuated the increases of IL-1β, IL-6 and TNF-α and upregulation of their receptors. MiR-155 inhibitor also attenuated upregulation of apoptotic Caspase-3 in the hippocampus of AD rats. Notably, inhibition of miR- 155 or PIC receptors largely recovered the impaired learning performance in AD rat.

Conclusion: We showed the critical role of miR-155 in regulating the memory impairment in AD rats likely via engagement of neuroinflammatory mechanisms, suggesting that miR-155 and its signaling molecules may present prospects in preventing and/or improving the development of the impaired cognitive functions in AD.

Keywords: Alzheimer's disease; Caspase-3; hippocampus; miroRNA-155; neuroinflammation; pro-inflammatory cytokines..

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alzheimer Disease / genetics
  • Alzheimer Disease / immunology
  • Alzheimer Disease / metabolism*
  • Animals
  • Cognitive Dysfunction / genetics
  • Cognitive Dysfunction / immunology
  • Cognitive Dysfunction / metabolism*
  • Gene Expression Regulation / genetics*
  • Hippocampus / immunology
  • Hippocampus / metabolism*
  • Inflammation / genetics
  • Inflammation / immunology
  • Inflammation / metabolism*
  • Male
  • MicroRNAs / genetics
  • MicroRNAs / immunology
  • MicroRNAs / metabolism*
  • Rats
  • Rats, Sprague-Dawley


  • MIRN155 microRNA, rat
  • MicroRNAs