Periosteum-derived mesenchymal stem cell alleviates renal fibrosis through mTOR-mediated Treg differentiation

Abstract

Background

Mesenchymal stem cells (MSCs) are the hotspots of cellular therapy due to their low immunogenicity, potent immunoregulation, and unique renoprotection. The present study aimed to investigate the effects of periosteum-derived MSCs (PMSCs) in ischemia–reperfusion (IR)-mediated renal fibrosis.

Methods

Using cell proliferation assay, flow cytometry, immunofluorescence, and histologic analysis, the differences in cell characteristics, immunoregulation, and renoprotection of PMSCs were compared to the bone marrow-derived MSCs (BMSCs), the most frequently studied stem cells in cellular therapy. In addition, the mechanism of PMSC renoprotection was investigated by 5′ end of the RNA transcript sequencing (SMART-seq) and mTOR knockout mice.

Results

The proliferation and differentiation capabilities of PMSCs were stronger than those of BMSCs. Compared with BMSCs, the PMSCs exerted a better effect on alleviating renal fibrosis. Meanwhile, the PMSCs more effectively promote Treg differentiation. Treg exhaustion experiment indicated that Tregs exerted an important effect on inhibiting renal inflammation and acted as a critical mediator in PMSC renoprotection. Additionally, SMART-seq results implied that the PMSCs promoted Treg differentiation, possibly via the mTOR pathway. In vivo and in vitro experiments showed that PMSC inhibited mTOR phosphorylation of Treg. After mTOR knockout, the PMSCs failed to promote Treg differentiation.

Conclusions

Compared with BMSCs, the PMSCs exerted stronger immunoregulation and renoprotection that was mainly attributed to PMSC promotion for Treg differentiation by inhibiting the mTOR pathway.

Keywords:

• Renal fibrosis
• mesenchymal stem cell
• regulatory T cells
• mTOR
• ischemia–reperfusion
• kidney transplantation

Acknowledgements

The authors wish to thank Professor Yong Zhao (the Institute of Zoology, Chinese Academy of Sciences, Beijing, China), who provided mTOR^–/– C57BL/6 mice.

Ethics statement

The experimental protocols were approved by the Animal Ethical Committee of Zhongshan Hospital, Fudan University (2020-142).

Author contributions

YL, KZ, and JW conceived the conception, performed experiments, analyzed data, and wrote the manuscript. HZ, JC, PZ, JG, CX, XN, YCC, SX, YC, and YZ participated in the study design and experiment. RR, XW, and DZ proposed the conception, supervised the experiments, and administered critical revision of the manuscript. All authors approved the manuscript.

Disclosure statement

The authors declare that there is no conflict of interest regarding the publication of this paper.

Data availability statement

Data for the information presented in the manuscript can be directed to the corresponding authors.

Additional information

Funding

This work was supported by the National Key R&D Program of China under Grant No. 2018YFA0107501; National Natural Science Foundation of China under Grant Nos. 81770747, 81970646, 82270789, and 81800659; and Shanghai Municipal Key Clinical Specialty under Grant No. shslczdzk05802.