Integrative small and long RNA-omics analysis of human healing and non-healing wounds discovers cooperating microRNAs as therapeutic targets

Due to microRNAs' (miRs) important functions and high potential for disease diagnosis and therapy, increasing efforts have been put to understand their role in wound repair and identify targetable miRs for wound treatment. However, lack of knowledge about miR-mediated gene expression in human wound tissues hinders the recognition of clinically relevant miRs. Here we profiled genome-wide miR and mRNA expression by RNA-sequencing in the same set of samples from human normal acute wounds and chronic non-healing venous ulcers (VU). By integrative analysis of miR and mRNA omics, we unraveled miR-mediated gene regulatory networks specifically associated with different phases of wound repair or VU. We also identified transcriptional factors and miR arm switching events underpinning the dynamically changed miR expression. In this study, we focused on not only a few top changed miRs, but also the miRs with their targetome enriched in the VU gene signature, such as miR-34a-5p, miR-34c-5p, miR-218-5p, miR-7704, miR-424-5p, miR-450-5p, miR-517b-3p, miR-96-5p, and miR-516b-5p. We confirmed these miRs' targetome in human keratinocytes and fibroblasts using microarrays and demonstrated their functional relevance to VU pathology. Twenty tissue samples from four groups (each N = 5), including Skin, Wound1, Wound7 and VU, were prepared for small RNA (miRNA-seq) and mRNA (mRNA-seq) library construction, respectively.