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Chun J, Riella CV, Chung H, Shah SS, Wang M, Magraner JM, Ribas GT, Ribas HT, Zhang JY, Alper SL, Friedman DJ, Pollak MR. DGAT2 Inhibition Potentiates Lipid Droplet Formation To Reduce Cytotoxicity in APOL1 Kidney Risk Variants. J Am Soc Nephrol 2022; 33:889-907. [PMID: 35232775 PMCID: PMC9063887 DOI: 10.1681/asn.2021050723] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 01/22/2022] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Two variants in the gene encoding apolipoprotein L1 (APOL1) that are highly associated with African ancestry are major contributors to the large racial disparity in rates of human kidney disease. We previously demonstrated that recruitment of APOL1 risk variants G1 and G2 from the endoplasmic reticulum to lipid droplets leads to reduced APOL1-mediated cytotoxicity in human podocytes. METHODS We used CRISPR-Cas9 gene editing of induced pluripotent stem cells to develop human-derived APOL1G0/G0 and APOL1G2/G2 kidney organoids on an isogenic background, and performed bulk RNA sequencing of organoids before and after treatment with IFN-γ. We examined the number and distribution of lipid droplets in response to treatment with inhibitors of diacylglycerol O-acyltransferases 1 and 2 (DGAT1 and DGAT2) in kidney cells and organoids. RESULTS APOL1 was highly upregulated in response to IFN-γ in human kidney organoids, with greater increases in organoids of high-risk G1 and G2 genotypes compared with wild-type (G0) organoids. RNA sequencing of organoids revealed that high-risk APOL1G2/G2 organoids exhibited downregulation of a number of genes involved in lipogenesis and lipid droplet biogenesis, as well as upregulation of genes involved in fatty acid oxidation. There were fewer lipid droplets in unstimulated high-risk APOL1G2/G2 kidney organoids than in wild-type APOL1G0/G0 organoids. Whereas DGAT1 inhibition reduced kidney organoid lipid droplet number, DGAT2 inhibition unexpectedly increased organoid lipid droplet number. DGAT2 inhibition promoted the recruitment of APOL1 to lipid droplets, with associated reduction in cytotoxicity. CONCLUSIONS Lipogenesis and lipid droplet formation are important modulators of APOL1-associated cytotoxicity. Inhibition of DGAT2 may offer a potential therapeutic strategy to attenuate cytotoxic effects of APOL1 risk variants.
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Affiliation(s)
- Justin Chun
- Department of Medicine, Division of Nephrology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
- Department of Medicine, Division of Nephrology, University of Calgary, Cumming School of Medicine, Calgary, Alberta, Canada
| | - Cristian V. Riella
- Department of Medicine, Division of Nephrology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Hyunjae Chung
- Department of Medicine, Division of Nephrology, University of Calgary, Cumming School of Medicine, Calgary, Alberta, Canada
| | - Shrijal S. Shah
- Department of Medicine, Division of Nephrology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Minxian Wang
- Cardiovascular Disease Initiative and the Program in Medical and Population Genetics, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Jose M. Magraner
- Department of Medicine, Division of Nephrology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Guilherme T. Ribas
- Professional and Technological Education Sector, Federal University of Paraná, Curitiba, Paraná, Brazil
| | - Hennrique T. Ribas
- Professional and Technological Education Sector, Federal University of Paraná, Curitiba, Paraná, Brazil
| | - Jia-Yue Zhang
- Department of Medicine, Division of Nephrology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Seth. L. Alper
- Department of Medicine, Division of Nephrology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - David J. Friedman
- Department of Medicine, Division of Nephrology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Martin R. Pollak
- Department of Medicine, Division of Nephrology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
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Ren Y, Ribas HT, Heath K, Wu S, Ren J, Shriwas P, Chen X, Johnson ME, Cheng X, Burdette JE, Kinghorn AD. Na +/K +-ATPase-Targeted Cytotoxicity of (+)-Digoxin and Several Semisynthetic Derivatives. J Nat Prod 2020; 83:638-648. [PMID: 32096998 PMCID: PMC7243443 DOI: 10.1021/acs.jnatprod.9b01060] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
(+)-Digoxin (1) is a well-known cardiac glycoside long used to treat congestive heart failure and found more recently to show anticancer activity. Several known cardenolides (2-5) and two new analogues, (+)-8(9)-β-anhydrodigoxigenin (6) and (+)-17-epi-20,22-dihydro-21α-hydroxydigoxin (7), were synthesized from 1 and evaluated for their cytotoxicity toward a small panel of human cancer cell lines. A preliminary structure-activity relationship investigation conducted indicated that the C-12 and C-14 hydroxy groups and the C-17 unsaturated lactone unit are important for 1 to mediate its cytotoxicity toward human cancer cells, but the C-3 glycosyl residue seems to be less critical for such an effect. Molecular docking profiles showed that the cytotoxic 1 and the noncytotoxic derivative 7 bind differentially to Na+/K+-ATPase. The HO-12β, HO-14β, and HO-3'aα hydroxy groups of (+)-digoxin (1) may form hydrogen bonds with the side-chains of Asp121 and Asn122, Thr797, and Arg880 of Na+/K+-ATPase, respectively, but the altered lactone unit of 7 results in a rotation of its steroid core, which depotentiates the binding between this compound and Na+/K+-ATPase. Thus, 1 was found to inhibit Na+/K+-ATPase, but 7 did not. In addition, the cytotoxic 1 did not affect glucose uptake in human cancer cells, indicating that this cardiac glycoside mediates its cytotoxicity by targeting Na+/K+-ATPase but not by interacting with glucose transporters.
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Affiliation(s)
- Yulin Ren
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, OH 43210, United States
| | - Hennrique T. Ribas
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, OH 43210, United States
| | - Kimberly Heath
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, United States
| | - Sijin Wu
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, OH 43210, United States
| | - Jinhong Ren
- Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, United States
| | - Pratik Shriwas
- Department of Biological Sciences, Edison Biotechnology Institute, and Molecular and Cellular Biology Program, Ohio University, Athens, OH 45701, United States
| | - Xiaozhuo Chen
- Department of Biological Sciences, Edison Biotechnology Institute, Molecular and Cellular Biology Program, and Department of Biomedical Sciences, Ohio University, Athens, OH 45701, United States
| | - Michael E. Johnson
- Department of Pharmaceutical Sciences and Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, United States
| | - Xiaolin Cheng
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, OH 43210, United States
| | - Joanna E. Burdette
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, United States
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