Fig. 1

Circ-Ntrk2 is upregulated in lung tissues of hypoxia-induced PAH mice and PASMCs. a Heat map analysis of circular RNA (circRNA) in lung tissues from hypoxia-exposed mice. b Volcano map analysis of circRNAs. c The differentially expressed circRNAs in the sequencing results were matched with the circBase data. d Quantitative polymerase chain reaction (qPCR) analysis of circRNA expression in hypoxic mouse lung tissues and PASMCs (n = 5). e Position of circ-Ntrk2 in its host gene Ntrk2. f Circ-Ntrk2 was spliced from the end of the mRNA Ntrk2 single exon; Sanger sequencing was used to verify the correctness of the cyclization site. g PCR assay with divergent and convergent primers showing the amplification of circRNA from cDNA or genomic DNA (gDNA), while GAPDH was used as a negative control. The gel or blot images have been cropped and the complete images have been submitted separately (Additional file 4). h qRT-PCR analysis of circ-Ntrk2 and Ntrk2 mRNA after treatment with RNase R. i Fluorescence in situ hybridisation (FISH) of lung tissues of mice exposed to hypoxia. All values are presented as the mean ± SD. *P < 0.05, **P < 0.01