Abstract: TH-OR130

Amelioration of Diabetic Nephropathy in miR-379 Knockout Mice

Session Information

Category: Diabetes

  • 501 Diabetes Mellitus and Obesity: Basic - Experimental

Authors

  • Kato, Mitsuo, Beckman Research Institute of City of Hope, Duarte, California, United States
  • Abdollahi, Maryam, Beckman Research Institute of City of Hope, Duarte, California, United States
  • Lanting, Linda L., Beckman Research Institute of City of Hope, Duarte, California, United States
  • Wang, Mei P, Beckman Research Institute of City of Hope, Duarte, California, United States
  • Natarajan, Rama, Beckman Research Institute of City of Hope, Duarte, California, United States
Background

Major features of diabetic nephropathy (DN) include extracellular matrix (ECM) accumulation, glomerular hypertrophy and fibrosis. Evidence shows that key microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) are involved in DN development. Recently we found that miR-379 megacluster of miRNAs and its host transcript lncRNA are regulated by endoplasmic reticulum (ER) stress, increased in glomeruli of diabetic mice and mediate early DN. Therefore, here we developed miR-379-knockout (KO) mice using CRISPR-Cas9 system to examine the hypothesis that miR-379, the first miRNA in the cluster, has an in vivo role in DN progression.

Methods

miR-379KO mice were generated by CRISPR-Cas9 nickase and dual guideRNA strategy. Diabetes was induced with streptozotocin (STZ) in 10 wk old wild type (WT-STZ) and miR379-KO (miR379-KO-STZ) C57BL/6 mice (n=6). Non-diabetic age/gender matched mice acted as control (WT-Con and miR379-KO-Con; n=6). Urine albumin excretion and urinary albumin/creatinine ratio (ACR) were measured before euthanization at 24 wks post diabetes induction. Renal glomeruli were isolated for measuring miRNAs, profibrotic and miR379 target genes. Cortical sections were stained for histopathology. Expression of TGFß1 and ER stress regulator EDEM3, a target of miR-379, were examined by immunohistochemical staining.

Results

miR-379KO mice did not depict any abnormalities, and developed diabetes to the same extent as WT mice. On the other hand, miR379-KO-STZ mice did not lose body weight like WT-STZ mice. Increased urine albumin and ACR in WT-STZ mice were attenuated in miR-379KO-STZ mice. Glomerular hypertrophy, ECM accumulation and fibrosis observed in WT-STZ mice were all significantly reduced in miR-379KO-STZ mice. Other candidate miRNAs in the miR-379 cluster (miR-495 and miR-377) were increased in glomeruli of WT-STZ, but not miR-379KO-STZ mice. Furthermore, increases in expression of profibrotic genes Col4α1, Col1α2, and TGF-ß1 seen in WT-STZ mice were significantly attenuated in miR-379KO-STZ mice. Conversely, decreased expression of EDEM3 in WT-STZ mice was not observed in miR-379KO-STZ mice.

Conclusion

Genetic deletion of miR-379 in mice by CRISPR-Cas9 system prevents glomerular hypertrophy and ECM accumulation associated with early DN. miR-379 and its target EDEM3 may play key roles in inducing ER stress and TGFß1 in diabetes to increase glomerular damage.

Funding

  • NIDDK Support