Abstract
Two variants at the APOL1 gene, encoding apolipoprotein L1, account for more than 70% of the increased risk for chronic kidney disease in individuals of African ancestry. While the initiating event for APOL1 risk variant cell injury remains to be clarified, we explored the possibility of blocking APOL1 toxicity at a more upstream level. We demonstrate that deletion of the first six amino acids of exon 4 abrogates APOL1 cytotoxicity by impairing APOL1 translocation to the lumen of ER and splicing of the signal peptide. Likewise, in orthologous systems, APOL1 lethality was partially abrogated in yeast strains and flies with reduced dosage of genes encoding ER translocon proteins. An inhibitor of ER to Golgi trafficking reduced lethality as well. We suggest that targeting the MSALFL sequence or exon 4 skipping may serve as potential therapeutic approaches to mitigate the risk of CKD caused by APOL1 renal risk variants.
| Original language | English |
|---|---|
| Article number | 103717 |
| Journal | iScience |
| Volume | 25 |
| Issue number | 1 |
| DOIs | |
| State | Published - 21 Jan 2022 |
| Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2022 The Authors
Funding
We acknowledge the support provided by Israel Science Foundation Grant 3757/20 , a grant from the Ernest and Bonnie Beutler Research Program in Genomic Medicine, and from the Kaylie Kidney Research Center of Excellence at Rambam.Part of this research work was presented as an abstract at the 12 th International Podocyte Conference (Canada, Montreal, 30/05-02/06/2018). This work was supported in part by the National Institute on Minority Health and Health Disparities Grant U54MD007586 and the National Heart, Lung, and Blood Institute (NHLBI) T32 Research Training in Cardiovascular Biology Grant 5T32HL007737-23 at Meharry Medical College (A.M.C. and S.E.D.) and Vanderbilt's Institute for Clinical and Translational Research ( VICTR ) VR51297 (A.M.C.). W.P. was supported by Paul Teschan Research Fund ( DCI ) 2014-02 and the NIH MeTRC 5U54MD007593-09 . We would like to thank Dr. Suzie Scales from Genentech for her expert advice and guidance with saponin/digitonin experiments, Maya Holdengreber for technical assistant with confocal microscopy, and Prof. Daniel Kornitzer and Prof. Adi Salzberg for their expert assistance and advice with yeast and flies experiments, respectively. Stocks obtained from the Bloomington Drosophila Stock Center (NIH P40OD018537) were used in this study. We acknowledge the support provided by Israel Science Foundation Grant 3757/20, a grant from the Ernest and Bonnie Beutler Research Program in Genomic Medicine, and from the Kaylie Kidney Research Center of Excellence at Rambam.Part of this research work was presented as an abstract at the 12th International Podocyte Conference (Canada, Montreal, 30/05-02/06/2018). This work was supported in part by the National Institute on Minority Health and Health Disparities Grant U54MD007586 and the National Heart, Lung, and Blood Institute (NHLBI) T32 Research Training in Cardiovascular Biology Grant 5T32HL007737-23 at Meharry Medical College (A.M.C. and S.E.D.) and Vanderbilt's Institute for Clinical and Translational Research (VICTR) VR51297 (A.M.C.). W.P. was supported by Paul Teschan Research Fund (DCI) 2014-02 and the NIH MeTRC 5U54MD007593-09. I. Bavli-Kertselli performed cloning and generated the Dox-inducible APOL1-expressing T-REx 293 cells, performed western Blot, immunofluorescence, brefeldin A, fractionation and cytotoxicity assays, and yeast work. A. Ofir performed cloning and yeast work. E. Zaknoun performed yeast work and S. Chornyy performed cloning. R. Shemer performed fly work. O. Tabachnikov performed the immunofluorescence studies. A. Cheatham, S. Davis, and A. Khatua constructed wild-type and mutated APOL1 expression vectors, performed cytotoxicity assays, and western blotting. E. Kruzel-Davila, K. Skorecki, and W. Popik contributed to experimental design, data analysis, and wrote the manuscript. KS and RS are inventors on Patent No.: US 10,927,414 B2. KS is an Associate Editor for The Kidney, 11th Edition, Elsevier 2020.
| Funders | Funder number |
|---|---|
| Meharry Medical College | |
| Paul Teschan Research Fund | |
| National Institutes of Health | P40OD018537, MeTRC 5U54MD007593-09 |
| National Heart, Lung, and Blood Institute | 5T32HL007737-23 |
| National Institute on Minority Health and Health Disparities | U54MD007586 |
| Vanderbilt Institute for Clinical and Translational Research | VR51297 |
| Duke Cancer Institute | 2014-02 |
| Israel Science Foundation | 30/05-02/06/2018, 3757/20 |
Keywords
- Cell biology
- Cellular physiology
- Functional aspects of cell biology