Transfer of MicroRNA-216a-5p From Exosomes Secreted by Human Urine-Derived Stem Cells Reduces Renal Ischemia/Reperfusion Injury.

Yinmei Zhang,Jie Ding,Di Wu,Hong Ye,Boxin Yang,Han Guo,Aiwei Li,Shuo Yang,Junxiong Wang,Liyan Cui,Rui Qiao,Hui Li

doi:10.3389/fcell.2020.610587

Abstract

Human urine-derived stem cells (USCs) protect rats against kidney ischemia/reperfusion (I/R) injury. Here we investigated the role of USCs exosomes (USCs-Exos) in protecting tubular endothelial cells and miRNA transfer in the kidney. Human USCs and USCs-Exos were isolated and verified by morphology and specific biomarkers. USC-Exos played a protective role in human proximal tubular epithelial cells (HK-2) exposed to hypoxia/reoxygenation (H/R). USCs-Exos were rich in miR-216a-5p, which targeted phosphatase and tensin homolog (PTEN) and regulated cell apoptosis through the Akt pathway. In HK-2 cells exposed to H/R, incubation with USC-Exos increased miR-216-5p, decreased PTEN levels, and stimulated Akt phosphorylation. Exposure of hypoxic HK-2 cells to USCs-Exos pretreated with anti-miR-216a-5p can prevent the increase of miR-216-5p and Akt phosphorylation levels, restore PTEN expression, and promote apoptosis. The dual-luciferase reported gene assay in HK-2 cells confirmed that miR-216a-5p targeted PTEN. In rats with I/R injury, intravenous infusion of USCs-Exos can effectively induce apoptosis suppression and functional protection, which is associated with decreased PTEN. Infusion of exosomes from anti-miR-216a-5p-transfected USCs weakened the protective effect in the I/R model. Therefore, USCs-Exos can reduce renal I/R injury by transferring miR-216a-5p targeting PTEN. Potentially, USCs-Exos rich in miR-216a-5p can serve as a promising therapeutic option for AKI.

Highlights

Renal ischemia/reperfusion (I/R) injury is one of the most common causes of acute kidney injury (AKI) and is strongly associated with tubular cell necrosis and endothelial cell dysfunction (Cui et al, 2011; Sharfuddin and Molitoris, 2011; Borisov and Shilov, 2017)
Urine-derived stem cells were isolated from freshly urine from 7 healthy male adults as described above
In cultured human proximal tubular epithelial cells (HK-2) cells exposed to H/R, administration of Urine-derived stem cells (USCs)-derived conditioned medium (CM) or exosomes significantly increased the levels of miR-216a-5p, whereas conditioned medium from USCs transfected with the miR-216a5p inhibitor blocked this increase (Figure 5A)

Summary

INTRODUCTION

Renal ischemia/reperfusion (I/R) injury is one of the most common causes of acute kidney injury (AKI) and is strongly associated with tubular cell necrosis and endothelial cell dysfunction (Cui et al, 2011; Sharfuddin and Molitoris, 2011; Borisov and Shilov, 2017). Exosomes are rich in proteins, mRNAs, miRNAs, and other molecules As carriers, they are taken up by renal tubular epithelial cells, macrophages, and endothelial cells and can participate in the regulation of the pathological process of renal I/R injury, such as cell proliferation, autophagy, apoptosis, oxidative stress, inflammatory response, angiogenesis, fibrosis, and immune escape. In vivo and in vitro studies have shown that exosomes derived from different types of stem cells could effectively protect against AKI (Grange et al, 2019). It is suggested that miR-216a5p can protect human proximal tubular epithelial cells (HK-2) against apoptosis by miRNA transfer, targeting the phosphatase and tensin homolog (PTEN) and activating Akt phosphorylation in vitro, while playing a role in recovering I/R damage in vivo

MATERIALS AND METHODS

RESULTS

DISCUSSION

ETHICS STATEMENT