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

• Published in: Biological procedures online Vol. 25; no. 1; p. 10
• Main Authors: Liu, Wei, Hu, Chenghuan, Zhang, Buyao, Li, Mingxia, Deng, Fuxing, Zhao, Shuangping
• Format: Journal Article
• Language: English
• Published: England BioMed Central 21-04-2023; BMC
• Subjects: Acute kidney injury; Adipose-derived mesenchymal stem cells; Animal models; Autophagy; Blood; Bone marrow; Cell culture; Creatinine; Epithelial cells; Exosome; Exosomes; Flow cytometry; Hospitals; Infections; Inflammation; Inflammatory diseases; Kidneys; Lipopolysaccharides; Mesenchymal stem cells; MicroRNAs; miR-342-5p; miRNA; Mitochondrial DNA; Patients; Reporter gene; Sepsis; Stem cells; TLR9; TLR9 protein; Toll-like receptors; Transfection; United States > US; China; TLR9; Adipose-derived mesenchymal stem cells; miR-342-5p; Exosome; Autophagy; Acute kidney injury
• ISSN: 1480-9222; 1480-9222
• DOI: 10.1186/s12575-023-00198-y

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