Search

Burkholderia pseudomalleiis the causative agent of melioidosis, a disease with high mortality, which is prevalent in tropical regions of the world. A recent study shows that B. pseudomalleican survive inside mammalian cells because of its ability to actively evade cell autophagy. However, the underlying mechanisms remain unclear. In the present study, based on microarray screening, we found that ATG10 was downregulated following B. pseudomalleiinfection in A549 human lung epithelial cells. Forced expression of ATG10 accelerated the elimination of intracellular B. pseudomalleiby enhancing the process of autophagy. Moreover, MIR4458, MIR4667-5p, and MIR4668-5pwere found, by microarray screening, to be upregulated in response to B. pseudomalleiinfection. These 3 novel miRNAs, MIR4458, MIR4667-5p, and MIR4668-5p, targeted to the 3′-untranslated region of ATG10in different time-course and spatial manners. Upregulation of these miRNAs reduced the level of ATG10 and inhibited autophagy, leading to increasing survival rate of intracellular B. pseudomallei. Furthermore, the increase of these miRNAs was correlated with the reduced promoter methylation status in A549 cells in response to B. pseudomalleiinfection. Our results reveal that 3 novel miRNAs regulate autophagy-mediated elimination of B. pseudomalleiby targeting ATG10, and provide potential targets for clinical treatment.

Helicobacter pylorievade immune responses and achieve persistent colonization in the stomach. However, the mechanism by which H. pyloriinfections persist is not clear. In this study, we showed that MIR30Bis upregulated during H. pyloriinfection of an AGS cell line and human gastric tissues. Upregulation of MIR30Bbenefited bacterial replication by compromising the process of autophagy during the H. pyloriinfection. As a potential mechanistic explanation for this observation, we demonstrate that MIR30Bdirectly targets ATG12 and BECN1, which are important proteins involved in autophagy. These results suggest that compromise of autophagy by MIR30Ballows intracellular H. pylorito evade autophagic clearance, thereby contributing to the persistence of H. pyloriinfections.