Small RNAs and extracellular vesicles in filarial nematodes: From nematode development to diagnostics

Parasitic nematodes have evolved sophisticated mechanisms to communicate with their hosts in order to survive and successfully establish an infection. The transfer of RNA within extracellular vesicles (EVs) has recently been described as a mechanism that could contribute to this communication in filarial nematodes. It has been shown that these EVs are loaded with several types of RNAs, including microRNAs, leading to the hypothesis that parasites could actively use these molecules to manipulate host gene expression and to the exciting prospect that these pathways could result in new diagnostic and therapeutic strategies. Here, we review the literature on the diverse RNAi pathways that operate in nematodes and more specifically our current knowledge of extracellular RNA (exRNA) and EVs derived from filarial nematodes in vitro and within their hosts. We further detail some of the issues and questions related to the capacity of RNA-mediated communication to function in parasite-host interactions and the ability of exRNA to enable us to distinguish and detect different nematode parasites in their hosts.

MicroRNAs: new players in IBD

MicroRNAs (miRNAs) are small non-coding RNAs, 18-23 nucleotides long, which act as post-transcriptional regulators of gene expression. miRNAs are strongly implicated in the pathogenesis of many common diseases, including IBDs. This review aims to outline the history, biogenesis and regulation of miRNAs. The role of miRNAs in the development and regulation of the innate and adaptive immune system is discussed, with a particular focus on mechanisms pertinent to IBD and the potential translational applications.