Adipose mesenchymal stem cell-derived extracellular vesicles containing microRNA-26a-5p target TLR4 and protect against diabetic nephropathy

J Biol Chem. 2020 Sep 11;295(37):12868-12884. doi: 10.1074/jbc.RA120.012522. Epub 2020 Jun 24.

Abstract

Diabetic nephropathy (DN) is a complication of diabetes that is increasing in prevalence in China. Extracellular vesicles (EVs) carrying microRNAs (miRs) may represent a useful tool in the development of therapies for DN. Here, we report that EVs released by adipose-derived mesenchymal stem cells (ADSCs) during DN contain a microRNA, miR-26a-5p, that suppresses DN. Using bioinformatic analyses, we identified differentially expressed miRs in EVs from ADSCs and in DN and predicted downstream regulatory target genes. We isolated mesenchymal stem cells (MSCs) from adipose tissues and collected EVs from the ADSCs. We exposed mouse glomerular podocytes and MP5 cells to high glucose (HG), ADSC-derived EVs, miR-26a-5p inhibitor/antagomir, Toll-like receptor 4 (TLR4) plasmids, or the NF-κB pathway activator (phorbol-12-myristate-13-acetate, or PMA). We used the cell counting kit-8 (CCK-8) assay and flow cytometry to investigate the impact of miR-26a-5p on cell viability and apoptosis and validated the results of these assays with in vivo experiments in nude mice. We found that in DN, miR-26a-5p is expressed at very low levels, whereas TLR4 is highly expressed. Of note, EVs from ADSCs ameliorated the pathological symptoms of DN in diabetic mice and transferred miR-26a-5p to HG-induced MP5 cells, improving viability while suppressing the apoptosis of MP5 cells. We also found that miR-26a-5p protects HG-induced MP5 cells from injury by targeting TLR4, inactivating the NF-κB pathway, and downregulating vascular endothelial growth factor A (VEGFA). Moreover, ADSC-derived EVs transferred miR-26a-5p to mouse glomerular podocytes, which ameliorated DN pathology. These findings suggest that miR-26a-5p from ADSC-derived EVs protects against DN.

Keywords: MicroRNA-328-3p; NF-κB; Toll-like receptor 4 (TLR4); adipose-derived mesenchymal stem cells; cell biology; cell culture; cell cycle; cell differentiation; diabetes; diabetic nephropathy; extracellular vesicles; inflammation; metabolic disorder; vascular endothelial growth factor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / metabolism*
  • Adipose Tissue / pathology
  • Animals
  • Diabetes Mellitus, Experimental* / metabolism
  • Diabetes Mellitus, Experimental* / pathology
  • Diabetes Mellitus, Experimental* / therapy
  • Diabetic Nephropathies* / metabolism
  • Diabetic Nephropathies* / pathology
  • Diabetic Nephropathies* / therapy
  • Extracellular Vesicles* / metabolism
  • Extracellular Vesicles* / pathology
  • Extracellular Vesicles* / transplantation
  • Male
  • Mesenchymal Stem Cells / metabolism*
  • Mesenchymal Stem Cells / pathology
  • Mice
  • MicroRNAs / metabolism*
  • Toll-Like Receptor 4 / metabolism*

Substances

  • MicroRNAs
  • Mirn26 microRNA, mouse
  • Tlr4 protein, mouse
  • Toll-Like Receptor 4