Kidney Week

Abstract: FR-OR18

In Vivo Base Editing Rescues ADPKD in Mice

Session Information

• Cystic Kidney Diseases: Basic and Translational Research
  October 25, 2024 | Location: Room 23, Convention Center
  Abstract Time: 05:50 PM - 06:00 PM

Category: Genetic Diseases of the Kidneys

• 1201 Genetic Diseases of the Kidneys: Cystic

Authors

• Cheng, Shasha, Mayo Clinic Minnesota, Rochester, Minnesota, United States

Shasha Cheng, PhD

• Li, Xiaoyan, Mayo Clinic Minnesota, Rochester, Minnesota, United States

Xiaoyan Li, MD, PhD

• Harris, Peter C., Mayo Clinic Minnesota, Rochester, Minnesota, United States

Peter C. Harris, PhD

• Zhou, Xia, Mayo Clinic Minnesota, Rochester, Minnesota, United States

Xia Zhou, MD, PhD

• Li, Xiaogang, Mayo Clinic Minnesota, Rochester, Minnesota, United States

Xiaogang Li, PhD

Background

ADPKD is the most prevalent genetic kidney disease, caused by mutations of the PKD1 and PKD2 genes, which drive renal cyst growth and extrarenal complications, including cardiac hypertrophy. Adeno-associated virus (AAV) delivered CRISPR-Cas9 base editing is a revolutionary approach for treating inherited diseases. However, thus far, the effect of AAV-BEs on DNA editing in ADPKD have not been reported.

Methods

To determine whether correction of the Pkd1 gene mutation in Pkd1^RC/RC mice, carrying an arginine (R) to cystine (C) mutation as in ADPKD patients, delays cyst growth and decreases heart hypertrophy, we treated Pkd1^RC/RC mice with one dose of two newly developed ABE9-AAV9 base editors through intravenous (IV) injection. To evaluate the effect of the ABE9-AVV9 base editing on lifespan, we treated Pkd1^RC/null mice with both base editor systems.

Results

We developed 1) a broadly expressed AAV9-ABE9 base editor system to correct Pkd1 gene mutation in whole body, and 2) a kidney specific AAV9-ABE9 base editor system to increase the efficiency and specificity of ABE9 base editor on correction of Pkd1 gene mutation in kidney only. We showed that one dose of broadly expressed AAV9-ABE9 base editor can effectively delay renal cyst growth and decrease cardiac hypertrophy in Pkd1^RC/RC mice, and that one dose of kidney-specific AVV9-ABE9 base editor is selectively expressed in kidneys, but not in hearts, resulting in efficiently delaying cyst growth in Pkd1^RC/RC kidneys. The precise editing efficiency with one dose of these two AAV9-ABE9 base editor systems remained stable in kidneys six months after treatment, increasing the expression of Pkd1 mRNA and a decrease of cyst index, KW/BW ratios, BUN levels in Pkd1^RC/RC mice. Treatment with AAV9-ABE9 base editors also decreased cystic cell proliferation and the accumulation of macrophages at interstitial and pericystic regions, and increased cyst lining epithelial cell apoptosis in Pkd1^RC/RC kidneys. Treatment with one dose of either the broadly expressed or kidney specific ABE9 base editor increased the survival rate of Pkd1^RC/null mice.

Conclusion

This is the first proof-of-principle study that use CRISPR/Cas9 base editing to correct a pathogenic single-nucleotide variant in an ADPKD mouse model, which demonstrates considerable potential for single-dose genetic therapies to correct pathogenic variants and prevent the development of ADPKD in the clinic.

Funding

• NIDDK Support