Exosomal microRNA-342-5p secreted from adipose-derived mesenchymal stem cells mitigates acute kidney injury in sepsis mice by inhibiting TLR9

Wei Liu; Chenghuan Hu; Buyao Zhang; Mingxia Li; Fuxing Deng; Shuangping Zhao

doi:10.1186/s12575-023-00198-y

Exosomal microRNA-342-5p secreted from adipose-derived mesenchymal stem cells mitigates acute kidney injury in sepsis mice by inhibiting TLR9

Biol Proced Online. 2023 Apr 21;25(1):10. doi: 10.1186/s12575-023-00198-y.

Authors

Wei Liu^#^{1

2

3}, Chenghuan Hu^#^{1

2

3}, Buyao Zhang¹, Mingxia Li¹, Fuxing Deng¹, Shuangping Zhao^{4

5

6}

Affiliations

¹ Department of Critical Care Medicine, Xiangya Hospital of Central South University, Changsha, Hunan, People's Republic of China.
² Hunan Provincial Clinical Research Center for Critical Care Medicine, Xiangya Hospital of Central South University, Changsha, Hunan, People's Republic of China.
³ National Clinical Research Center for Geriatric Disorders, Xiangya Hospital of Central South University, Changsha, Hunan, People's Republic of China.
⁴ Department of Critical Care Medicine, Xiangya Hospital of Central South University, Changsha, Hunan, People's Republic of China. zhshping@csu.edu.cn.
⁵ Hunan Provincial Clinical Research Center for Critical Care Medicine, Xiangya Hospital of Central South University, Changsha, Hunan, People's Republic of China. zhshping@csu.edu.cn.
⁶ National Clinical Research Center for Geriatric Disorders, Xiangya Hospital of Central South University, Changsha, Hunan, People's Republic of China. zhshping@csu.edu.cn.

^# Contributed equally.

Abstract

Background: Sepsis-related acute kidney injury (AKI) is an inflammatory disease associated with extremely high mortality and health burden. This study explored the possibility of exosomes secreted by adipose-derived mesenchymal stem cells (AMSCs) serving as a carrier for microRNA (miR)-342-5p to alleviate sepsis-related AKI and investigated the possible mechanism.

Methods: Serum was obtained from 30 patients with sepsis-associated AKI and 30 healthy volunteers for the measurement of miR-342-5p, blood urea nitrogen (BUN), and serum creatinine (SCr) levels. For in vitro experiments, AMSCs were transfected with LV-miR-342-5p or LV-miR-67 to acquire miR-342-5p-modified AMSCs and miR-67-modified AMSCs, from which the exosomes (AMSC-Exo-342 and AMSC-Exo-67) were isolated. The human renal proximal tubular epithelial cell line HK-2 was induced by lipopolysaccharide (LPS) to construct a cellular model of sepsis. The expression of Toll-like receptor 9 (TLR9) was also detected in AKI cells and mouse models. The interaction between miR-342-5p and TLR9 was predicted by dual luciferase reporter gene assay.

Results: Detection on clinical serum samples showed that BUN, SCr, and TLR9 were elevated and miR-342-5p level was suppressed in the serum of patients with sepsis-associated AKI. Transfection with LV-miR-342-5p reinforced miR-342-5p expression in AMSCs and AMSC-secreted exosomes. miR-342-5p negatively targeted TLR9. LPS treatment enhanced TLR9 expression, reduced miR-342-5p levels, suppressed autophagy, and increased inflammation in HK-2 cells, while the opposite trends were observed in LPS-induced HK-2 cells exposed to AMSC-Exo-342, Rapa, miR-342-5p mimic, or si-TLR9. Additionally, the effects of AMSC-Exo-342 on autophagy and inflammation in LPS-induced cells could be weakened by 3-MA or pcDNA3.1-TLR9 treatment. Injection of AMSC-Exo-342 enhanced autophagy, mitigated kidney injury, suppressed inflammation, and reduced BUN and SCr levels in sepsis-related AKI mouse models.

Conclusion: miR-342-5p transferred by exosomes from miR-342-5p-modified AMSCs ameliorated AKI by inhibiting TLR9 to accelerate autophagy.

Keywords: Acute kidney injury; Adipose-derived mesenchymal stem cells; Autophagy; Exosome; TLR9; miR-342-5p.

Abstract

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