mRNA profiling of hypoxia+SU5416-induced pulmonary hypertension (PH) mouse model treated with an inhibitor of miR-130/301 family

Purpose: Guided by an in silico combination of microRNA (miRNA) target prediction, analysis of transcriptomic changes in 137 human diseases, and advanced gene network modeling, we predicted the miR-130/301 family of miRNAs as a shared regulator of a fibrotic gene network across human diseases, thus orchestrating broad control over disease manifestation. The goals of this study are to compare the lung mRNA profile of mouse model of Pulmonary hypertension, one of the most fibrotic pathology uncovered by our in silico prediction, treated with an inhibitor of miR-130/301 (Short-130) to mice treated with a control inhibitor (Short-NC). Methods: Eight-week-old mice (C57BL/6) were injected with SU5416 (20 mg/kg/dose; Sigma-Aldrich), followed by exposure to normobaric hypoxia (10% O2; OxyCycler chamber, Biospherix Ltd.) for 2 weeks. After 2 weeks and confirmation of PH development in 5 mice (right heart catheterization), mice were further treated with 3 intrapharyngeal injections (every 4 days) of control or miR-130/301 shortmer oligonucleotides, designed as fully modified antisense oligonucleotides complementary to the seed sequence of the miR-130/301 miRNA family (10 mg/kg/dose; Regulus). Specifically, the control and miR-130/301 shortmer oligonucleotides were nontoxic, lipid-permeable, high-affinity oligonucleotides. The miR-130/301 shortmer carried a sequence complementary to the active site of the miR-130/301 miRNA family, containing a phosphorothioate backbone and modifications (fluoro-, methoxyethyl, and bicyclic sugar) at the sugar 2' position. Three days after the last injection, right heart catheterization was performed followed by harvesting of lung tissue for RNA extraction. Lung mRNA profiles of those mice or control mice (Normoxia+SU5416) were generated by deep sequencing, in triplicate, using Illumina HiSeq 2000. The sequence reads that passed quality filters were analyzed at the gene-level count. The gene level counts were then normalized with the R/Bioconductor package limma using the voom /variance stabilization method. The data were quality controlled for outliers using principal component analysis (PCA). Differential expression analysis between transcriptome profiles of experimental groups was performed using the R / Bioconductor package limma. Results: Transcriptomic analyses of whole lung from mice with hypoxia+SU5416-induced PH revealed a generalized de-repression of miR-130/301 targets by Short-130 treatment. Importantly, although whole lung transcriptomics likely captured only a subset of the miR-130/301 targets affecting the diseased pulmonary vasculature, pathway enrichment nonetheless revealed pronounced representation of several pathways known to be involved in fibrosis. Thus, the miR-130/301 family indeed induces a programmatic shift at the molecular level toward the fibrotic pathophenotype in vivo Overall design: Whole lung mRNA profiles of Normoxia (Control) and hypoxia+SU5416-induced PH mice treated with Short-NC or Short-130 were generated by deep sequencing, in triplicate, using Illumina HiSeq 2000.

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Bertero T, Cottrill KA, Lu Y, Haeger CM, Dieffenbach P, Annis S, Hale A, Bhat B, Kaimal V, Zhang YY, Graham BB, Kumar R, Saggar R, Saggar R, Wallace WD, Ross DJ, Black SM, Fratz S, Fineman JR, Vargas SO, Haley KJ, Waxman AB, Chau BN, Fredenburgh LE, Chan SY