Integrative Analysis of ceRNA Networks in human periodontal ligament stem cells under hypoxia

Circ-SPATA13 regulates the osteogenic differentiation of human periodontal ligament stem cells through the miR-485-5p_R + 1/BMP7 axis

BACKGROUND

Human periodontal ligament stem cells (PDLSCs) are widely available and have strong osteogenic differentiation ability, which makes them promising tools for bone regeneration. Circular RNAs (circRNAs) play a variety of functions in the process of cell differentiation and are potential therapeutic targets. Here, we identified a new circRNA, circ-SPATA13, and found that it was highly positively correlated with the osteogenic differentiation of PDLSCs. Therefore, in this study, we revealed the significance and mechanism of circ-SPATA13 in the osteogenic differentiation of PDLSCs.

METHODS

PDLSCs were isolated from third molars with incomplete apical development and induced to undergo chondrogenic, adipogenic, or osteogenic differentiation. Surface markers were detected via flow cytometry. Proliferation was assessed with EdU and CCK-8 assays. The circ-SPATA13 and miR-485-5p_R + 1-mediated control of mineral deposition was evaluated through alizarin red and alkaline phosphatase staining. Osteogenesis-related factor expression was detected through western blotting, immunofluorescence, and qRT-PCR. Fluorescence in situ hybridization was used to examine circ-SPATA13 localization within PDLSCs. The relationships among circ-SPATA13, miR-485-5p_R + 1, and BMP7 during PDLSCs osteogenesis were assessed through western blotting, qRT-PCR, dual-luciferase assay, rescue experiment, and bioinformatics approaches.

RESULTS

Primary PDLSCs expressing mesenchymal stem cell surface markers were isolated. Circ-SPATA13 was identified and found to have no impact on PDLSC proliferation, whereas it was a positive regulator of their osteogenic differentiation, a process which was antagonized by miR-485-5p_R + 1. Dual-luciferase reporter assays revealed that circ-SPATA13 was able to function as a molecular sponge to sequester miR-485-5p_R + 1 within PDLSCs, while this miRNA was able to bind to the 3'-UTR of the target mRNA BMP7. In rescue experiments, circ-SPATA13 was confirmed to regulate the osteogenic differentiation of PDLSCs via this miR-485-5p_R + 1/BMP7 axis. Moreover, in vivo experiments in rats demonstrated that the overexpression of circ-SPATA13 in PDLSCs was associated with the promotion of bone formation in a skull defect model system.

CONCLUSION

These data supported the osteogenic functions of circ-SPATA13 in PDLSCs. Mechanistically, this circRNA was found to function as a molecular sponge for miR-485-5p_R + 1, in turn targeting BMP7 to promote the osteogenic differentiation of PDLSCs. This circ-SPATA13/miR-485-5p_R + 1/BMP7 axis may be a novel target for treatments promoting PDLSCs osteogenic differentiation.

The Effects of Hypoxia-Preconditioned Dental Stem Cell-Derived Secretome on Tissue Regeneration

Mesenchymal stroma cells derived from oral tissues are known as dental stem cells (DSCs). Owing to their unique therapeutic niche and clinical accessibility, DSCs serve as a promising treatment option for bone defects and oral tissue regeneration. DSCs exist in a hypoxic microenvironment in vivo, which is far lower than the current 20% oxygen concentration used in in vitro culture. It has been widely reported that the application of an oxygen concentration less than 5% in the culture of DSCs is beneficial for preserving stemness and promoting proliferation, migration, and paracrine activity. The paracrine function of DSCs involves the secretome, which includes conditioned media (CM) and soluble bioactive molecules, as well as extracellular vesicles extracted from CM. Hypoxia can play a role in immunomodulation and angiogenesis by altering the protein or nucleic acid components in the secretory group, which enhances the therapeutic potential of DSCs. This review summarizes the biological characteristics of DSCs, the influence of hypoxia on DSCs, the impact of hypoxia on the secretory group of DSCs, and the latest progress on the use of DSCs secretory group in tissue regeneration based on hypoxia pretreatment. We highlighted the multifunctional biological effect of hypoxia culture on tissue regeneration and provided a summary of the current mechanism of hypoxia in the pretreatment of DSCs.

CircRNA-mediated heterogeneous ceRNA regulation mechanism in periodontitis and peri-implantitis

BACKGROUND

Performing a comprehensive study on the differential expression of mRNAs, miRNAs, and circRNAs in the context of peri-implantitis and periodontitis has beneficial advantages to identify unique molecular signatures and pathways that may contribute to our understanding of these conditions.

METHODS

Gingival tissues from healthy individuals and peri-implantitis and periodontitis patients were obtained to identify differential expression genes (DEG) by Illumina HiSeq 2500 instrument. Differential expression analysis was conducted using R statistical software, with significance set at P < 0.05 and fold greater than 2. Functional enrichment analysis of the DEGs was conducted using the Reactome, Gene ontology and KEGG databases.

RESULTS

Significant differences in mRNA, miRNA, and circRNA profiles were identified between healthy gingival tissues. The top DEGs comprising 6 circRNAs, 2 miRNAs, and 4 mRNAs were identified and the constructed ceRNA network, elucidates their involvement in key signaling pathways such as ErbB, Wnt, and mTOR, which are crucial for understanding the inflammatory progression of these conditions.

CONCLUSIONS

This study highlights a heterogeneous circRNA-mediated ceRNA regulatory mechanism in peri-implantitis and periodontitis, activating signaling pathways and regulating gene expression. Key findings including a detailed analysis of the transcriptional landscape and identification of unique molecular signatures, pathways and cellular components in gingival tissues, offering insights into the molecular differences between peri-implantitis and periodontitis. The study may contribute to the understanding of the pathological mechanisms of these diseases and may aid in the development of targeted therapies.

The signaling pathways involved in non-coding RNA regulation during osteogenic differentiation of periodontal tissue-derived cells in the field of periodontitis

Periodontitis is a prevalent oral disease caused by chronic inflammation of the periodontal tissues surrounding the teeth, which can lead to bone loss, tooth loosening, and even tooth loss. This inflammation has a negative impact on the osteogenic differentiation capacity of periodontal tissue-derived cells. Non-coding RNAs (ncRNAs) are a class of RNA molecules that do not encode proteins but can regulate various physiological processes. In this review, we summarized the critical signaling pathways that ncRNAs modulate in osteogenic differentiation of periodontal tissue-derived cells, such as the Wnt, BMP/Smad, NF-κB, and PI3-K/Akt/mTOR pathways. This comprehensive exploration of ncRNA-mediated modulation offers fresh and promising insights for prospective approaches in the management of periodontitis and the advancement of periodontal regeneration therapies.

Mesenchymal Stem Cell-Derived from Dental Tissues-Related lncRNAs: A New Regulator in Osteogenic Differentiation

Odontogenic stem cells are mesenchymal stem cells (MSCs) with multipotential differentiation potential from different dental tissues. Their osteogenic differentiation is of great significance in bone tissue engineering. In recent years, it has been found that long noncoding RNAs (lncRNAs) participate in regulating the osteoblastic differentiation of stem cells at the epigenetic level, transcriptional level, and posttranscriptional level. We reviewed the existing lncRNA related to the osteogenic differentiation of odontogenic stem cells and emphasized the critical mechanism of lncRNA in the osteogenic differentiation of odontogenic stem cells. These findings are expected to be an important target for promoting osteoblastic differentiation of odontogenic stem cells in bone regeneration therapy with lncRNA.