Background: Human dental pulp stem cells (hDPSCs) are critical for pulp generation. hDPSCs proliferate faster under hypoxia, but the regulatory mechanism of long noncoding RNAs (lncRNAs) in this process is not fully understood.

Methods: Novel lncRNAs were obtained by reanalysis of transcriptome datasets coming from RNA-Seq under hypoxia compared with normoxia, and differential expression analysis of target genes were performed. Bioinformatics analyses including Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and Gene Set Enrichment Analysis (GSEA) analysis were used to understand the function of key novel lncRNA. hDPSCs were isolated from dental pulp tissue. EdU test and scratch healing test were used to detect the proliferation and migration of hDPSCs. qRT-PCR was used to detect the RNA level expression changes of selected genes. RNA fluorescence in situ hybridization (FISH), small interfering RNA (siRNA), qRT-PCR and western blot analysis were used to explore the function of key novel lncRNA.

Results: We identified 496 novel lncRNAs in hDPSCs under hypoxia, including 45 expressed differentially novel lncRNAs. Of them, we focused on a key novel lncRNA, which we named HRL-SC (hypoxia related lncRNA in stem cells). Functional annotation revealed that HRL-SC was associated with hypoxic conditions and PI3K/AKT signalling pathway. HRL-SC was mainly located in the cytoplasm of hDPSCs and had stably high expression under hypoxia. Knockdown of HRL-SC inhibited proliferation and migration of hDPSCs and expression levels of PI3K/AKT related marker proteins. Furthermore, AKT activator SC79 partially offset the inhibitory effect caused by the knockdown, indicating that HRL-SC promoted hDPSCs through PI3K/AKT signalling pathway

.Conclusion: Hypoxia related lncRNA HRL-SC promotes proliferation and migration of hDPSCs through PI3K/AKT signalling pathway and it may provide a better understanding for regenerative application of hDPSCs.

Journal Link: 10.21203/rs.3.rs-1143046/v1 Journal Link: Publisher Website Journal Link: Download PDF Journal Link: Google Scholar