Abstract: SA-PO0037
MANF Regulates Endoplasmic Reticulum Calcium Efflux in Patient-Derived Kidney Organoids of Autosomal Dominant Tubulointerstitial Kidney Disease
Session Information
- Development, Stem Cells, and Regenerative Medicine
October 24, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Development, Stem Cells, and Regenerative Medicine
- 700 Development, Stem Cells, and Regenerative Medicine
Authors
- Fang, Yili, Washington University in St Louis School of Medicine, St. Louis, Missouri, United States
- Gu, Chenjian, Washington University in St Louis School of Medicine, St. Louis, Missouri, United States
- Li, Chuang, Washington University in St Louis School of Medicine, St. Louis, Missouri, United States
- Urano, Fumihiko, Washington University in St Louis School of Medicine, St. Louis, Missouri, United States
- Kidd, Kendrah O., Wake Forest University, Winston-Salem, North Carolina, United States
- Bleyer, Anthony J., Wake Forest University, Winston-Salem, North Carolina, United States
- Liu, Jun, Shanghai General Hospital, Shanghai, China
- Sun, Zhao, The University of Texas at Dallas, Richardson, Texas, United States
- Lindahl, Maria, Helsingin yliopisto, Helsinki, Uusimaa, Finland
- Chen, Ying Maggie, Washington University in St Louis School of Medicine, St. Louis, Missouri, United States
Background
Autosomal dominant tubulointerstitial kidney disease (ADTKD) caused by uromodulin (UMOD) mutations is a prominent monogenic chronic kidney disease, accounting for 21% of cases in the US. While mutant UMOD is known to trigger endoplasmic reticulum (ER) stress, effective therapies remain elusive. In this study, we investigated the endogenous role of mesencephalic astrocyte-derived neurotrophic factor (MANF), a promising therapeutic ER chaperone, in maintaining ER calcium homeostasis in ADTKD patient-derived kidney organoids.
Methods
We generated human induced pluripotent stem cells (hiPSCs) from an ADTKD patient carrying the UMOD p.H177-R185 del mutation and an unaffected family member. To delineate MANF function, we employed inducible CRISPR/Cas9 to establish hiPSC lines with tetracycline (Tet)-inducible MANF knockout (KO). Thick ascending limb (TAL) cells were subsequently isolated using a magnetic bead conjugation system for downstream molecular analysis. ER calcium depletion was monitored in live organoids using a secreted ER calcium-monitoring protein (SERCaMP) reporter. Finally, we utilized qPCR and immunofluorescence (IF) confocal microscopy to determine the expression profile of key ER calcium efflux channels, specifically the different isoforms of inositol trisphosphate receptors (IP3Rs) and ryanodine receptors.
Results
Patient-derived hiPSCs were successfully differentiated into organoids, with the mutant line recapitulating the hallmark disease features, including ER retention of mutant UMOD and the subsequent ER stress-triggered MANF induction. Using the SERCaMP assay, we detected a significant increase in ER calcium depletion within the mutant organoids. This enhanced ER calcium leak was mediated by the selective upregulation of IP3R1 in organoid-isolated TALs. Furthermore, inducible MANF knockout in these models revealed that loss of induced MANF augmented ER calcium leakage specifically in the mutant organoids.
Conclusion
Our findings demonstrate that MANF deficiency exacerbates IP3R1-mediated ER calcium leakage, highlight the MANF-IP3R1 axis as a pivotal regulator of ER calcium balance and TAL biological function. Furthermore, these patient-derived organoids establish a robust platform for developing targeted, novel therapeutics for ADTKD.
Acknowledgment
Y.L.F is supported by the American Heart Association Postdoctoral Fellowship. C.J.G is supported by American Society of Nephrology (ASN) Kidney Cure Ben J. Lipps Research Fellowship Program. Y.M.C. is supported by NIH grants R01 2DK105056-6,R56DK138158A1, R21DK131557A1, R03DK106451 and K08DK089015, VA Merit I01BX006401A1
Funding
- NIDDK Support