Kidney Week

Abstract: PO1668

Molecular and Functional Characterization of Human Urinary APOL1 G2/G2 High-Risk Genotype Podocyte

Session Information

• Podocyte Injury in Human Disease: Pathomechanism, Diagnosis, and Therapy
  November 04, 2021 | Location: On-Demand, Virtual Only
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1204 Podocyte Biology

Authors

• Adebayo, Oyindamola Christiana, Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, Katholieke Universiteit Leuven, Leuven, Belgium

Oyindamola Christiana Adebayo, MS

• Ekulu, Pepe Mfutu, Department of Development and Regeneration, Katholieke Universiteit Leuven, Leuven, Belgium

Pepe Mfutu Ekulu,

• Decuypere, Jean-Paul, Department of Development and Regeneration, Katholieke Universiteit Leuven, Leuven, Flanders, Belgium

Jean-Paul Decuypere,

• Elmonem, Mohamed A., Department of Development and Regeneration, Katholieke Universiteit Leuven, Leuven, Belgium

Mohamed A. Elmonem,

• Nkoy, Agathe Bikupe, Department of Development and Regeneration, Katholieke Universiteit Leuven, Leuven, Belgium

Agathe Bikupe Nkoy,

• Mekahli, Djalila, Department of Development and Regeneration, Katholieke Universiteit Leuven, Leuven, Flanders, Belgium

Djalila Mekahli,

• Bussolati, Benedetta, Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy

Benedetta Bussolati,

• Van Den Heuvel, L.P.W.J., Department of Development and Regeneration, Katholieke Universiteit Leuven, Leuven, Belgium

L.P.W.J. Van Den Heuvel,

• Arcolino, Fanny Oliveira, Department of Development and Regeneration, Katholieke Universiteit Leuven, Leuven, Flanders, Belgium

Fanny Oliveira Arcolino,

• Levtchenko, Elena N., Department of Development and Regeneration, Katholieke Universiteit Leuven, Leuven, Flanders, Belgium

Elena N. Levtchenko,

Group or Team Name

• Laboratory of Pediatric Nephrology, Department of Development and Regeneration, Katholieke Universiteit Leuven, Leuven, Belgium

Background

Apolipoprotein L1 (APOL1) risk variants, G1 and G2, increase the risk of various non-diabetic kidney diseases in the African population. To date, the precise mechanisms by which APOL1 risk variants induce injury on podocytes and other kidney cells remain unclear. Trying to unravel these mechanisms, most studies used animal or cell models created by gene editing.

Methods

Conditionally immortalized human podocyte cell lines from urine of a donor carrying APOL1 high risk genotype, G2/G2 was developed. The APOL1 G2/G2 cell lines were characterized for podocyte markers at both the mRNA and the protein levels, using real-time quantitative PCR, Western blot and immunofluorescence staining. Following induction of APOL1 expression by 50 µg/mL polyinosinic-polycytidylic acid (poly(I:C)), we assessed the functional features of APOL1-induced podocyte dysfunction such as cell detachment, cell viability, cell death, autophagy, cytoskeleton organization and podocyte permeability. As control, APOL1 wild type (G0/G0) podocytes previously generated from a Caucasian donor were used.

Results

We successfully generated human APOL1 G2/G2 urinary podocyte cell lines. Upon exposure to poly(I:C), G2/G2 and G0/G0 podocytes upregulated APOL1 expression resulting in podocytes detachment, decreased cells viability and increased apoptosis rate in a genotype-independent manner. G2/G2 podocyte cell lines exhibited altered features, including upregulation of CD2AP, alteration of cytoskeleton, reduction of autophagic flux and increased permeability in an in vitro model under continuous perfusion.

Conclusion

The human APOL1 G2/G2 podocyte cell model is a useful tool for unraveling the mechanisms of APOL1-induced podocyte injury and the cellular functions of APOL1.