Disruption of APOL1-miR193a Axis Induces Disorganization of Podocyte Actin Cytoskeleton

Sci Rep. 2019 Mar 5;9(1):3582. doi: 10.1038/s41598-019-39376-y.

Abstract

APOL1-miR193a axis participates in the preservation of molecular phenotype of differentiated podocytes (DPDs). We examined the hypothesis that APOL1 (G0) preserves, but APOL1 risk alleles (G1 and G2) disrupt APOL1-miR193a axis in DPDs. DPDG0s displayed down-regulation of miR193a, but upregulation of nephrin expression. DPDG1s/G2s exhibited an increase in miR193a and down-regulation of the expression of adherens complex's constituents (CD2AP, nephrin, and dendrin). DPDG0s showed decreased Cathepsin L, enhanced dynamin expressions, and the intact actin cytoskeleton. On the contrary, DPDG1s/G2s displayed an increase in Cathepsin L, but down-regulation of dynamin expressions and disorganization of the actin cytoskeleton. APOL1 silencing enhanced miR193a and Cathepsin L, but down-regulated dynamin expressions. DPDG1s/G2s displayed nuclear import of dendrin, indicating an occurrence of destabilization of adherens complexes in APOL1 risk milieu. These findings suggest that DPDG1s and DPDG2s developed disorganized actin cytoskeleton as a consequence of disrupted APOL1-miR193a axis. Interestingly, docking and co-labeling studies suggested an interaction between APOL1 and CD2AP. APOL1G1/G1 and APOL1G1/G2 transgenic mice displayed nuclear import of dendrin indicating destabilization of adherens complexes in podocytes; moreover, these mice showed a four-fold increase in urinary albumin to creatinine ratio and development of focal segmental glomerular lesions.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Cytoskeleton / metabolism*
  • Adaptor Proteins, Signal Transducing / metabolism
  • Alleles
  • Animals
  • Apolipoprotein L1 / chemistry
  • Apolipoprotein L1 / genetics
  • Apolipoprotein L1 / metabolism*
  • Cell Differentiation
  • Cytoskeletal Proteins / metabolism
  • Gene Expression Regulation
  • Humans
  • Mice
  • Models, Molecular
  • Podocytes / cytology*
  • Podocytes / metabolism
  • Protein Conformation
  • Signal Transduction

Substances

  • Adaptor Proteins, Signal Transducing
  • Apolipoprotein L1
  • CD2-associated protein
  • Cytoskeletal Proteins