Klotho deficiency aggravates diabetes-induced podocyte injury due to DNA damage caused by mitochondrial dysfunction

Int J Med Sci. 2020 Sep 28;17(17):2763-2772. doi: 10.7150/ijms.49690. eCollection 2020.

Abstract

Diabetic nephropathy (DN) is a progressive disease, the main pathogeny of which is podocyte injury inducing glomerular filtration barrier and proteinuria. The occurrence and development of DN could be partly attributed to the reactive oxygen species (ROS) generated by mitochondria. However, research on how mitochondrial dysfunction (MtD) ultimately causes DNA damage is poor. Here, we investigated the influence of Klotho deficiency on high glucose (HG)-induced DNA damage in vivo and in vitro. First, we found that the absence of Klotho aggravated diabetic phenotypes indicated by podocyte injury accompanied by elevated urea albumin creatinine ratio (UACR), creatinine and urea nitrogen. Then, we further confirmed that Klotho deficiency could significantly aggravate DNA damage by increasing 8-OHdG and reducing OGG1. Finally, we demonstrated Klotho deficiency may promote MtD to promote 8-OHdG-induced podocyte injury. Therefore, we came to a conclusion that Klotho deficiency may promote diabetes-induced podocytic MtD and aggravate 8-OHdG-induced DNA damage by affecting OOG1.

Keywords: DNA damage; Klotho; diabetes; mitochondrial dysfunction (MtD); podocyte injury.

MeSH terms

  • Animals
  • Blood Glucose / metabolism
  • DNA Damage
  • Diabetes Mellitus, Experimental / blood
  • Diabetes Mellitus, Experimental / chemically induced
  • Diabetes Mellitus, Experimental / complications*
  • Diabetes Mellitus, Type 2 / blood
  • Diabetes Mellitus, Type 2 / chemically induced
  • Diabetes Mellitus, Type 2 / complications*
  • Diabetic Nephropathies / blood
  • Diabetic Nephropathies / genetics
  • Diabetic Nephropathies / pathology*
  • Glucuronidase / deficiency*
  • Glucuronidase / genetics
  • Humans
  • Klotho Proteins
  • Male
  • Mice
  • Mice, Transgenic
  • Microscopy, Electron, Transmission
  • Mitochondria / genetics
  • Mitochondria / pathology
  • Mitochondria / ultrastructure
  • Podocytes / cytology
  • Podocytes / pathology*
  • Podocytes / ultrastructure
  • Streptozocin / administration & dosage
  • Streptozocin / toxicity

Substances

  • Blood Glucose
  • Streptozocin
  • Glucuronidase
  • Klotho Proteins