Abstract: FR-PO0303
Renal Tubule-Specific Deletion of Angiotensinogen Gene Ameliorates Tubulopathy via Attenuation of Mitochondrial Dysfunction and Senescence in Akita Mouse Kidneys
Session Information
- Diabetic Kidney Disease: Basic and Translational Science Advances - 1
November 07, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Diabetic Kidney Disease
- 701 Diabetic Kidney Disease: Basic
Authors
- Yang, Wenxia, Centre de Recherche du Centre Hospitalier de l'Universite de Montreal, Montreal, Quebec, Canada
- Liao, Min-Chun, Centre de Recherche du Centre Hospitalier de l'Universite de Montreal, Montreal, Quebec, Canada
- Peng, Junzheng, Centre de Recherche du Centre Hospitalier de l'Universite de Montreal, Montreal, Quebec, Canada
- Yamashita, Michifumi, Cedars-Sinai Medical Center, Los Angeles, California, United States
- Miyata, Kana, Saint Louis University, St. Louis, Missouri, United States
- Filep, Janos G., Hopital Maisonneuve-Rosemont Centre de Recherche, Montreal, Quebec, Canada
- Ingelfinger, Julie R., Massachusetts General Hospital, Boston, Massachusetts, United States
- Zhang, Shao-Ling, Centre de Recherche du Centre Hospitalier de l'Universite de Montreal, Montreal, Quebec, Canada
- Chan, John S.D., Centre de Recherche du Centre Hospitalier de l'Universite de Montreal, Montreal, Quebec, Canada
Background
We have reported that renal tubule (RT)-specific angiotensinogen (Agt) gene deletion attenuates glomerular hyperfiltration, tubular injury, and urinary albumin-creatinine ratio, and decreases SGLT2 expression in T1D Akita mice (Diabetes 2025). The present study aimed to investigate if RT-deletion of Agt attenuates tubulopathy and explore underlying mechanisms.
Methods
We studied male non-diabetic control, RT-Agt knockout (KO), Akita, and Akita RT-Agt KO mice at 20 and 42 weeks. HK-2 (human immortalized proximal tubule cell line) and MDCK (Madin-Darby Canine Kidney) cells were also studied. Renal proximal tubular (RPT) and distal tubular (DT) cell size, luminal area, mitochondrial function, senescence and senescence-associated secretory phenotype (SASP) expression were assessed.
Results
RPT and DT cell size, luminal area, oxidative stress (dihydroethidium staining), oxidative DNA damage (8-Hydroxy-2’-deoxyguanosine staining) and disruption of mitochondrial cristae (electronic microscopy) were significantly increased in Akita mice. These abnormalities were markedly attenuated in Akita RT-Agt- KO mice. Akita kidneys also exhibited senescence-associated β-galactosidase (SA β-Gal) activity and SASP (Ccl2, Cxcl1 and Tnf-α) expression. Moreover, immunofluorescent staining of Ang II was increased and colocalized with the DT marker (lycopersicon esculentum lectin) in Akita mice, along with elevated markers of oxidative DNA damage and senescence marker (p16). These changes were significantly attenuated in Akita RT-Agt KO mice. In vitro, culture of HK cells with high glucose (35 mM D-glucose) and Ang II evoked mitochondrial oxidative stress, reduced mitochondrial transmembrane potential (MitoSox and JC1 staining, respectively) and augmented SA β-Gal activity. These changes were attenuated by losartan (an AT1R blocker) or apocynin (an NOX4 inhibitor). Finally, addition of senescent MDCK-derived conditioned medium to HK-2 cells facilitated the epithelial-to-mesenchymal transition in HK2 cells and vice versa, which was reversed by losartan or apocynin treatment.
Conclusion
RT-derived Agt/Ang II triggers tubulopathy, at least in part, through ROS-mediated DNA damage, mitochondrial dysfunction and senescence in Akita mice.
Funding
- Government Support – Non-U.S.