Exosomes derived from stem cells from the apical papilla alleviate inflammation in rat pulpitis by upregulating regulatory T cells

Si Yu; Xu Chen; Yao Liu; Xue Y Zhuang; Ao C Wang; Xue M Liu; Shu Zhu

doi:10.1111/iej.13721

Exosomes derived from stem cells from the apical papilla alleviate inflammation in rat pulpitis by upregulating regulatory T cells

Int Endod J. 2022 May;55(5):517-530. doi: 10.1111/iej.13721. Epub 2022 Mar 29.

Authors

Si Yu^{1

2}, Xu Chen^{1

2}, Yao Liu^{1

2}, Xue Y Zhuang^{1

2}, Ao C Wang^{1

2}, Xue M Liu^{1

2}, Shu Zhu^{1

2}

Affiliations

¹ Department of Paediatric Dentistry, School and Hospital of Stomatology, China Medical University, Shenyang, China.
² Liaoning Province Key Laboratory of Oral Disease, Shenyang, China.

PMID: 35274316
DOI: 10.1111/iej.13721

Abstract

Aim: To evaluate the effects of exosomes derived from stem cells from the apical papilla (SCAP-Exos) in rats with experimentally induced pulpitis and the effects of SCAP-Exos on the conversion of regulatory T cells (Tregs) and methylation status of the Foxp3 locus in Tregs in vitro.

Methodology: SCAP-Exos were isolated and identified using transmission electron microscopy, western blotting, and nanoparticle tracking analysis. Lipopolysaccharide was used to experimentally induced pulpitis in rats, and the effects of SCAP-Exos on the rats with pulpitis were detected using haematoxylin-eosin staining and immunofluorescence staining. CD4⁺ CD25^- T cells were treated with different doses of SCAP-Exos, and flow cytometric analysis was used to assess the effects of SCAP-Exos on Treg proliferation and conversion. An enzyme-linked immunosorbent assay (ELISA) was used to evaluate the expression of interleukin 10 (IL-10). MethylTarget^® technology was used to measure the methylation level of the Foxp3 locus in T cells. The expression levels of ten-eleven-translocation (Tet) 1, Tet2, and Tet3 in T cells were detected by real-time PCR and western blotting.

Results: SCAP-Exos had an elliptical vesicle-like structure with a diameter of approximately 143.7 nm and expressed the exosomal markers Alix and CD9. SCAP-Exo administration increased Treg accumulation in the inflamed dental pulp and alleviated inflammation in the dental pulp in vivo. SCAP-Exos promoted Treg conversion in vitro. Mechanistically, SCAP-Exos promoted Tet2-mediated Foxp3 demethylation to maintain the stable expression of Foxp3.

Conclusions: SCAP-Exos promoted Treg conversion and effectively alleviated inflammation in the dental pulp of rats. This study shows that SCAP-Exos can regulate the local immune microenvironment to favour tissue regeneration, thus providing a potential novel strategy utilising SCAP-Exos as a cell-free approach to treat early inflammation of dental pulp in immature permanent teeth in the clinic.

Keywords: exosomes; immunomodulation; pulpitis; rat experimental pulpitis; regulatory T cells (Tregs); stem cells from the apical papilla (SCAP).

MeSH terms

Animals
Exosomes*
Forkhead Transcription Factors
Inflammation
Pulpitis*
Rats
Stem Cells
T-Lymphocytes, Regulatory

Substances

Forkhead Transcription Factors

Abstract

MeSH terms

Substances

Grants and funding