Mycobacterium tuberculosis-induced miR-155 subverts autophagy by targeting ATG3 in human dendritic cells

Let-7a promotes microglia M2 polarization by targeting CKIP-1 following ICH

Microglia polarization plays a crucial role in initiating brain inflammatory injury after intracerebral hemorrhage (ICH). Casein Kinase 2 Interacting Protein 1(CKIP-1) has been identified as a transcriptional molecular to manipulate microglia polarization. MiRNAs regulate gene expression and microglia polarization. In the experiment, CKIP-1 has been predicted as a target gene of let-7a. Let-7a, CKIP-1 and downstream proinflammatory mediator production of ICH mice were analyzed. In addition, inflammation, brain edema, and neurological functions in ICH mice were also assessed. Furthermore, let-7a mimic or inhibitors was administrated to study the potential role to manipulate microglia polarization after ICH. We reported that let-7a levels decreased but CKIP-1 levels increased after ICH. Using a dual-luciferase reporter assay, it was demonstrated that CKIP-1 was the target gene of let-7a. Let-7a overexpression decreased the protein levels of CKIP-1 and inhibition of let-7a increased the protein levels of CKIP-1. In addition, our results indicate that let-7a could inhibit expression of proinflammatory cytokines, reduce brain edema, and improve neurological functions in ICH mice. The study indicated that CKIP-1 was a target gene of let-7a and that let-7a regulated microglia M2 polarization by targeting CKIP-1 following ICH.

miRNAs in immune responses to Mycobacterium tuberculosis infection

Tuberculosis (TB) is one of the most fatal infectious diseases, affecting one third of the world's population. The causative agent, Mycobacterium tuberculosis (Mtb), has a well-established ability to circumvent the host's immune system for its long-term intracellular survival. MicroRNAs (miRNAs) are crucial post-transcriptional regulators of immune response. They act by negatively regulating the expression levels of important genes in both innate and adaptive immunity. It has been established in recent studies that the host immune response against Mtb is regulated by many miRNAs, most of which are induced by Mtb infection. Moreover, differential expression of miRNA in tuberculosis (TB) patients may help distinguish between TB patients and healthy individuals or latent TB. In this review, we present the recent advancements on the miRNA regulation of the host responses against Mtb infection, as well as the potential of miRNAs to as biomarkers for TB diagnosis.