Abstract
BackgroundThe ACVR1/Alk-2 gene, encoding a BMP type I receptor, is mutated in Fibrodysplasia Ossificans Progressiva, a severe form of heterotopic ossification. Regulation of ACVR1/Alk-2 expression, still poorly understood, is likely to be controlled by transcriptional and post-transcriptional mechanisms. In our work, we focused on the functional role of the 3′UTR region of the gene and on microRNAs as possible modulators of the ACVR1/Alk-2 expression.ResultsThe ACVR1/Alk-2 3′UTR region consists of a 1.1 kb sequence harboring several putative, well-conserved binding sites for miRNAs in its proximal half, and AU-rich elements in the distal one, as assessed by bioinformatic analysis. The functional role of this region was tested in presence of transcription inhibitors and in transfection experiments in different cell lines, with a ACVR1/Alk-2-3′UTR reporter construct. By this transfection-based approach, we have also verified that three microRNAs, among those predicted to target ACVR1/Alk-2 gene by in silico analysis, can bind its 3′UTR sequence thereby modulating its expression.ConclusionIn this work we demonstrated that the ACVR1/Alk-2 transcript is unstable in presence of inhibitors of transcription. Functional analysis of the 3′UTR region by Luciferase reporter assays showed that it plays an inhibitory role on ACVR1/Alk-2 gene expression. Moreover, we found that specific miRNAs are involved in modulating ACVR1/Alk-2 gene expression as suggested by binding sites prediction in its 3′UTR sequence. In particular, we found that mir148b and mir365 were able to down-regulate ACVR1/Alk-2 expression, whereas mir26a showed a positive effect on its mRNA. Our data contribute to elucidate some of the mechanisms intervening in the modulation of ACVR1/Alk-2 expression. Considering that no specific and effective treatment of FOP is available, clarifying the basic mechanisms of the ACVR1/Alk-2 gene biology may provide means to develop innovative therapeutics approaches.
Highlights
A large class of small noncoding RNAs, known as microRNAs, functions as regulators of a broad range of cellular processes by modulating gene expression
ACVR1/Alk-2 gene is widely expressed in different tissues and cell lines and, like other receptors of important and critical signaling pathways, is likely to be targeted by different regulatory mechanisms of its gene expression
The 39UTR region of the ACVR1-Alk-2 gene consists of a 1.1 kb sequence highly conserved among species, in particular the percentage of identity between human and mouse is around 85% (Fig. 1A and Fig. S1)
Summary
A large class of small noncoding RNAs, known as microRNAs (miRs), functions as regulators of a broad range of cellular processes by modulating gene expression. One of the most important pathways is related to Bone Morphogenetic Protenis (BMPs) that act through the interplay between BMP ligands, BMP receptors and downstream intracellular signaling molecules. SMAD-dependent and non SMAD pathways act downstream of BMP receptors [2]. Both defective and hyperfunctioning BMP signaling can be observed as cause of abnormal clinical phenotypes in humans. We focused on the functional role of the 39UTR region of the gene and on microRNAs as possible modulators of the ACVR1/Alk-2 expression
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
