Pluto Bioinformatics

GSE88791: Two MicroRNAs and NF-kB Act in a Unique Regulatory Network to Ensure Precision of the Acute Inflammatory Response in Macrophages

Bulk RNA sequencing

The innate inflammatory response must be tightly regulated to ensure effective immune protection while avoiding inflammation-related pathologies. The transcription factor NF-kB is a critical mediator of the inflammatory response, and its dysregulation has been associated with immune related malignancies. We herein show that miR-155, miR-146a and NF-kB form a regulatory network that tunes the macrophage inflammatory response in mice. We show that elevated miR-155 expression potentiates NF-kB activity in miR-146a deficient mice, thus leading to an overactive acute inflammatory response and chronic inflammation. Enforced miR-155 expression overrides miR-146a-mediated repression of NF-kB activation, thus emphasizing that miR-155 plays a dominant, downstream role in promoting inflammation. We further show that miR-155 deficient macrophages exhibit a suboptimal inflammatory response when exposed to low levels of inflammatory stimuli. Importantly, we demonstrate a temporal asymmetry between miR-155 and miR-146a expression during macrophage activation, which forms a combined positive and negative feedback network on NF-kB activity. This miRNA based regulatory network enables a robust and time-limited inflammatory response essential for functional immunity. SOURCE: Georgi,K,Mairnov (georgi@caltech.edu) - California Institute of Technology