Pluripotent and Multipotent Stem Cells Display Distinct Hypoxic miRNA Expression Profiles

Abstract

MicroRNAs are reported to have a crucial role in the regulation of self-renewal and differentiation of stem cells. Hypoxia has been identified as a key biophysical element of the stem cell culture milieu however, the link between hypoxia and miRNA expression in stem cells remains poorly understood. We therefore explored miRNA expression in hypoxic human embryonic and mesenchymal stem cells (hESCs and hMSCs). A total of 50 and 76 miRNAs were differentially regulated by hypoxia (2% O2) in hESCs and hMSCs, respectively, with a negligible overlap of only three miRNAs. We found coordinate regulation of precursor and mature miRNAs under hypoxia suggesting their regulation mainly at transcriptional level. Hypoxia response elements were located upstream of 97% of upregulated hypoxia regulated miRNAs (HRMs) suggesting hypoxia-inducible-factor (HIF) driven transcription. HIF binding to the candidate cis-elements of specific miRNAs under hypoxia was confirmed by Chromatin immunoprecipitation coupled with qPCR. Role analysis of a subset of upregulated HRMs identified linkage to reported inhibition of differentiation while a downregulated subset of HRMs had a putative role in the promotion of differentiation. MiRNA-target prediction correlation with published hypoxic hESC and hMSC gene expression profiles revealed HRM target genes enriched in the cytokine:cytokine receptor, HIF signalling and pathways in cancer. Overall, our study reveals, novel and distinct hypoxia-driven miRNA signatures in hESCs and hMSCs with the potential for application in optimised culture and differentiation models for both therapeutic application and improved understanding of stem cell biology.

Human milk extracellular vesicle miRNA expression and associations with maternal characteristics in a population-based cohort from the Faroe Islands

“…Interestingly, a variant in the apolipoprotein C-III ( APOC3 ) gene was found to create a miR-4271 binding site in the corresponding mRNA, which was associated with lower plasma triglycerides, potentially increasing risk of coronary heart disease 50 . Other studies demonstrated that miR-4271 expression was upregulated in the plasma of smokers in comparison to nonsmokers 51 and following hypoxia in human embryonic stem cells 52 , suggesting that miR-4271 may be responsive to environmental stressors though its function in human milk remains unknown. The second most highly expressed miRNA in human milk EVs, miR-3197, has been suggested to be semen-specific in forensic studies 53 , 54 , however, miR-3197 expression was detected in human mesenchymal stem cells 55 , human placenta 56 , serum from patients with hepatocellular carcinoma 57 .…”

Hypoxia-Modified Cancer Cell Metabolism

“…They do not code proteins, but regulate post-transcriptional and translational gene expression. These molecules have multiple actions contributing to diverse normal and pathological cellular processes, including cell death, development, metabolism, neuronal patterning and oncogenesis (Pocock, 2011; Yu et al, 2012; Agrawal et al, 2016). Research indicates that a group of microRNAs are regulated by HIF-1, and in other instances, HIF-1 is the target of microRNAs.…”

Hypoxic hUCMSC-derived extracellular vesicles attenuate allergic airway inflammation and airway remodeling in chronic asthma mice

“…6 b). We also screened Nor-EVs or Hypo-EVs for several known anti-inflammatory and anti-remodeling miRNAs including let-7, miR-485, miR-29b, and miR-30a [ 37 ], which are regulated under hypoxia in MSCs [ 18 , 38 ]. Intriguingly, among the miRNAs, miR-146a-5p was the most abundant in Nor-EVs or in Hypo-EVs (see Additional file 3 ).…”