ASN's Mission

To create a world without kidney diseases, the ASN Alliance for Kidney Health elevates care by educating and informing, driving breakthroughs and innovation, and advocating for policies that create transformative changes in kidney medicine throughout the world.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on X

Kidney Week

Abstract: TH-OR62

Mesencephalic Astrocyte-Derived Neurotrophic Factor (MANF) Stimulates Autophagy and Restores Mitochondrial Homeostasis to Treat Uromodulin-Associated Nephropathy

Session Information

Category: Genetic Diseases of the Kidneys

  • 1202 Genetic Diseases of the Kidneys: Non-Cystic

Authors

  • Li, Chuang, Washington University in St Louis School of Medicine, St Louis, Missouri, United States
  • Kim, Yeawon, 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
  • Fang, Yili, Washington University in St Louis School of Medicine, St Louis, Missouri, United States
  • Tycksen, Eric, Washington University in St Louis School of Medicine, St Louis, Missouri, United States
  • Puri, Anuradhika, Washington University in St Louis, St Louis, Missouri, United States
  • Pietka, Terri A., Washington University in St Louis School of Medicine, St Louis, Missouri, United States
  • Sivapackiam, Jothilingam, Washington University in St Louis School of Medicine, St Louis, Missouri, United States
  • Kidd, Kendrah O., Wake Forest University School of Medicine, Winston-Salem, North Carolina, United States
  • Park, Sun-Ji, Washington University in St Louis School of Medicine, St Louis, Missouri, United States
  • Johnson, Bryce G., Pfizer Inc, New York, New York, United States
  • Kmoch, Stanislav, Univerzita Karlova, Praha, Czechia
  • Duffield, Jeremy Stuart, Prime Medicine, Cambridge, Massachusetts, United States
  • Bleyer, Anthony J., Wake Forest University School of Medicine, Winston-Salem, North Carolina, United States
  • Jackrel, Meredith, Washington University in St Louis, St Louis, Missouri, United States
  • Urano, Fumihiko, Washington University in St Louis School of Medicine, St Louis, Missouri, United States
  • Sharma, Vijay, Washington University in St Louis School of Medicine, St Louis, Missouri, 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 due to uromodulin mutations (ADTKD-UMOD), a leading hereditary kidney disease, has no targeted therapies. UMOD is expressed in the thick ascending limb (TAL) tubules, and p.H177_R185del in-frame deletion is the most prevalent human mutation.

Methods

CRISPR/Cas9 was utilized to generate an ADTKD-UMOD mouse model carrying Umod p.Y178_R186del, analogous to human H177_R185del. To assess the functional role of mesencephalic astrocyte-derived neurotrophic factor (MANF) in ADTKD, inducible tubular cell-specific MANF transgenic and TAL-specific MANF knockout mice were generated. Meanwhile, stable HEK cell line harboring WT or H177_R185del was established. RNA sequencing was performed on isolated TAL cells. Immunoblot, q-PCR, immunofluorescence staining and electron microscopy were employed. Mitochondria function was assessed by Oroboros high resolution respirometry and mitochondrial ROS was monitored by 68Ga-Galuminox PET/CT in live animals for the first time.

Results

Mutant TALs exhibit impaired autophagy/mitophagy and mitochondrial dysfunction. Subsequently, mitochondrial DNA leaking to cytosol leads to activation of stimulator of interferon genes (STING) signaling, inflammation and renal fibrosis in Umod Y178-R186del mice. MANF, a novel endoplasmic reticulum stress-regulated secreted protein, is induced in the mutant TALs. Genetic ablation of MANF in the mutant TALs worsens autophagy and mitochondrial failure and exacerbates kidney fibrosis. Most importantly, inducible tubular overexpression of MANF after the onset of disease stimulates autophagy/mitophagy and kidney clearance of mutant UMOD, as well as promotes mitochondrial biogenesis and oxidative phosphorylation through p-AMPK and downstream FOXO3 and PGC1a enhancement. Consequently, tubular MANF overexpression suppresses STING-mediated inflammation and fibrosis, thereby improving kidney function.

Conclusion

For the first time, we discover that MANF, as a novel biotherapeutic protein, can regulate organelle homeostasis and treat ADTKD, which may have broad therapeutic applications to treat various protein misfolding diseases.

Funding

  • NIDDK Support