Page 19 - IBRO_RNA School_Abstract Book

The microRNA editing spectrum of human brain in

health and disease

Arijit Mukhopadhyay

University of Salford, Manchester, UK

RNA editing is a post-transcriptional modification, which can provide tissue-

specific functions not encoded in DNA. Adenosine-to-inosine is the predominant
editing event and, along with cytosine-to-uracil changes, constitutes canonical
editing. The rest is non-canonical editing. We have analysed both canonical and
non-canonical editing in microRNA from the human brain and confirmed its
absence at the DNA level. All types of editing were enriched in brain including
many recurring events, which indicated functional relevance and importance.
Editing in microRNAs, particularly in seed can significantly alter the choice of
their target genes. We found an enrichment of the seed-editing events except for
C-to-U editing. Further, small RNA sequencing of brain cancer patients
(Glioblastoma multiforme) identified significant miRNA hypo-editing which
correlated with downregulation of ADAR2 both in metadata and qRT-PCR based
validation. Our results implicate miRNA non-canonical editing as one of the

contributing factors towards transcriptomic diversity in the human brain –
especially in the post-mitotic neurons, where the limited cell division and DNA
replication can limit its potential to create and maintain diversity.

References: (i) Paul D, Ansari AH, Lal M, Mukhopadhyay A. Noncoding RNA.
2020 Jun 2;6(2):21. doi: 10.3390/ncrna6020021.PMID: 32498345
(ii) Paul D, Sinha AN, Ray A, Lal M, Nayak S, Sharma A, Mehani B, Mukherjee D,
Laddha SV, Suri A, Sarkar C, Mukhopadhyay A. Sci Rep. 2017 May
26;7(1):2466. doi: 10.1038/s41598-017-02397-6.PMID: 28550310