The role of microRNAs in the pathogenesis of MMPi-induced skin fibrodysplasia

miR-370 and miR-373 regulate the pathogenesis of osteoarthritis by modulating one-carbon metabolism via SHMT-2 and MECP-2, respectively

The aim of this study was to determine the mechanism underlying the association between one-carbon metabolism and DNA methylation during chronic degenerative joint disorder, osteoarthritis (OA). Articular chondrocytes were isolated from human OA cartilage and normal cartilage biopsied, and the degree of cartilage degradation was determined by safranin O staining. We found that the expression levels of SHMT-2 and MECP-2 were increased in OA chondrocytes, and 3′UTR reporter assays showed that SHMT-2 and MECP-2 are the direct targets of miR-370 and miR-373, respectively, in human articular chondrocytes. Our experiments showed that miR-370 and miR-373 levels were significantly lower in OA chondrocytes compared to normal chondrocytes. Overexpression of miR-370 or miR-373, or knockdown of SHMT-2 or MECP-2 reduced both MMP-13 expression and apoptotic cell death in cultured OA chondrocytes. In vivo, we found that introduction of miR-370 or miR-373 into the cartilage of mice that had undergone destabilization of the medial meniscus (DMM) surgery significantly reduced the cartilage destruction in this model, whereas introduction of SHMT-2 or MECP-2 increased the severity of cartilage destruction. Together, these results show that miR-370 and miR-373 contribute to the pathogenesis of OA and act as negative regulators of SHMT-2 and MECP-2, respectively.

microRNA profiling in the zoonotic parasite Echinococcus canadensis using a high-throughput approach

Background

microRNAs (miRNAs), a class of small non-coding RNAs, are key regulators of gene expression at post-transcriptional level and play essential roles in fundamental biological processes such as development and metabolism. The particular developmental and metabolic characteristics of cestode parasites highlight the importance of studying miRNA gene regulation in these organisms. Here, we perform a comprehensive analysis of miRNAs in the parasitic cestode Echinococcus canadensis G7, one of the causative agents of the neglected zoonotic disease cystic echinococcosis.

Methods

Small RNA libraries from protoscoleces and cyst walls of E. canadensis G7 and protoscoleces of E. granulosus sensu stricto G1 were sequenced using Illumina technology. For miRNA prediction, miRDeep2 core algorithm was used. The output list of candidate precursors was manually curated to generate a high confidence set of miRNAs. Differential expression analysis of miRNAs between stages or species was estimated with DESeq. Expression levels of selected miRNAs were validated using poly-A RT-qPCR.

Results

In this study we used a high-throughput approach and found transcriptional evidence of 37 miRNAs thus expanding the miRNA repertoire of E. canadensis G7. Differential expression analysis showed highly regulated miRNAs between life cycle stages, suggesting a role in maintaining the features of each developmental stage or in the regulation of developmental timing. In this work we characterize conserved and novel Echinococcus miRNAs which represent 30 unique miRNA families. Here we confirmed the remarkable loss of conserved miRNA families in E. canadensis, reflecting their low morphological complexity and high adaptation to parasitism.

Conclusions

We performed the first in-depth study profiling of small RNAs in the zoonotic parasite E. canadensis G7. We found that miRNAs are the preponderant small RNA silencing molecules, suggesting that these small RNAs could be an essential mechanism of gene regulation in this species. We also identified both parasite specific and divergent miRNAs which are potential biomarkers of infection. This study will provide valuable information for better understanding of the complex biology of this parasite and could help to find new potential targets for therapy and/or diagnosis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-015-0686-8) contains supplementary material, which is available to authorized users.