Using miRNA-mRNA Interaction Analysis to Link Biologically Relevant miRNAs to Stem Cell Identity Testing for Next-Generation Culturing Development.

UNLABELLED: Therapeutic benefit of stem cells has been demonstrated in multiple disease models and clinical trials. Robust quality assurance is imperative to make advancements in culturing procedures to enable large-scale cell manufacturing without hampering therapeutic potency. MicroRNAs (miRNAs or miRs) are shown to be master regulators of biological processes and are potentially ideal quality markers. We determined miRNA markers differentially expressed under nonclinical multipotent adult progenitor cell (MAPC) and mesenchymal stem cell (MSC) culturing conditions that regulate important stem cell features, such as proliferation and differentiation. These bone marrow-derived stem cell types were selected because they both exert therapeutic functions, but have different proliferative and regenerative capacities. To determine cell-specific marker miRNAs and assess their effects on stem cell qualities, a miRNA and mRNA profiling was performed on MAPCs and MSCs isolated from three shared donors. We applied an Ingenuity Pathway Analysis-based strategy that combined an integrated RNA profile analysis and a biological function analysis to determine the effects of miRNA-mRNA interactions on phenotype. This resulted in the identification of important miRNA markers linked to cell-cycle regulation and development, the most distinctive being MAPC marker miR-204-5p and MSC marker miR-335-5p, for which we provide in vitro validation of its function in differentiation and cell cycle regulation, respectively. Importantly, marker expression is maintained under xeno-free conditions and during bioreactor isolation and expansion of MAPC cultures. In conclusion, the identified biologically relevant miRNA markers can be used to monitor stem cell stability when implementing variations in culturing procedures. SIGNIFICANCE: Human adult marrow stromal stem cells have shown great potential in addressing unmet health care needs. Quality assurance is imperative to make advancements in large-scale manufacturing procedures. MicroRNAs are master regulators of biological processes and potentially ideal quality markers. MicroRNA and mRNA profiling data of two human adult stem cell types were correlated to biological functions in silico. Doing this provided evidence that differentially expressed microRNAs are involved in regulating specific stem cell features. Furthermore, expression of a selected microRNA panel was maintained in next-generation culturing platforms, demonstrating the robustness of microRNA profiling in stem cell comparability testing.

Analysis of the translationally controlled tumour protein in the nematodes Ostertagia ostertagi and Caenorhabditis elegans suggests a pivotal role in egg production.

The translationally controlled tumour protein (TCTP) is a conserved protein which has been described for a wide range of eukaryotic organisms including protozoa, yeasts, plants, nematodes and mammals. Several parasitic organisms have been shown to actively secrete TCTP during host infection as part of their immuno-evasive strategy. In this study, we have studied TCTP in Ostertagia ostertagi, a parasitic nematode of cattle, and in the free-living nematode Caenorhabditis elegans. An analysis of the transcription and expression patterns showed that TCTP was present in the eggs of both species. This localisation is consistent for some other Strongylida such as Teladorsagia circumcincta, Cooperia oncophora and Haemonchus contortus. TCTP was also detected at low levels in excretory-secretory material from adult O. ostertagi worms. The role of TCTP in nematode biology was also investigated by RNA interference in C. elegans. Knock-down of C. elegans tctp (tct-1) transcription reduced the numbers of eggs laid by the hermaphrodite in the F(0) and F(1) generations by 90% and 72%, respectively, indicating a pivotal role of TCTP in reproduction.

RNA interference in parasitic nematodes of animals: a reality check?

RNA interference (RNAi) is widely used in Caenorhabditis elegans to identify gene function and has been adapted as a high-throughput screening method to identify genes involved in essential processes. The technique has been applied to parasitic nematodes with variable success and we believe that inconsistent outcomes preclude its use as a robust screen with which to identify potential control targets. In this article, key issues that require clarification are discussed, including the mode of delivery of double-stranded RNA to the parasite, the developmental stage targeted and, perhaps of most importance, whether the RNAi pathway (as defined by studies in C. elegans) is fully functional in some parasitic nematodes.