Knockdown of the long noncoding RNA VSIG2-1:1 promotes the angiogenic ability of human pulmonary microvascular endothelial cells by activating the VEGF/PI3K/AKT pathway.

Background: Abnormal pulmonary vascular development poses significant clinical challenges for infants with bronchopulmonary dysplasia (BPD). Although numerous factors have been suggested to control the development of pulmonary blood vessels, the mechanisms underlying the role of long noncoding RNAs (lncRNAs) in this process remain unclear.

Methods: A lncRNA array was used to measure the differential expression of lncRNAs in premature infants with and without BPD. The expression of lncRNA-VSIG2-1:1 in patients with BPD and hyperoxia-induced human pulmonary microvascular endothelial cells (HPMECs) was assessed using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Fluorescence in situ hybridization (FISH) assay was performed to detect the subcellular localization of lncRNA-VSIG2-1:1. Pulmonary microvascular endothelial cells were stably transfected with adenoviral vectors to silence or overexpress lncRNA-VSIG2-1:1. The effects of lncRNA-VSIG2-1:1 on the proliferation, migration, and tube formation abilities of HPMECs subjected to hyperoxia were examined by performing Cell Counting Kit-8 (CCK-8), cell migration, and tubule formation assays. RNA sequencing (RNA-seq) was performed to determine the correlation between lncRNA-VSIG2-1:1 and phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT). The protein levels of vascular endothelial growth factor (VEGF), p-PI3K, PI3K, p-AKT, and AKT were determined using western blotting.

Results: The expression of lncRNA-VSIG2-1:1 was upregulated in patients with BPD and hyperoxia-treated HPMECs. Inhibiting lncRNA-VSIG2-1:1 expression promoted the proliferation, migration, and tube-formation abilities of HPMECs, while significantly increasing VEGF, p-PI3K, and p-AKT levels.

Conclusion: Our findings reveal that the suppression of lncRNA-VSIG2-1:1 expression stimulates angiogenesis in vitro by inducing the initiation of the VEGF/PI3K/AKT signaling pathway. This observation may aid the development of novel therapeutic targets for treating BPD.