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Abstract: FR-PO0644

Intravital Imaging of Intact Kidney Tubules in Live Pkd1 Targeted Mice Using Upright Two-Photon Microscopy

Session Information

Category: Genetic Diseases of the Kidneys

  • 1201 Genetic Diseases of the Kidneys: Monogenic Kidney Diseases

Authors

  • Mohammadi, Ario, Brigham and Women's Hospital, Boston, Massachusetts, United States
  • Qureshi, Muhammad Hamza, Brigham and Women's Hospital, Boston, Massachusetts, United States
  • Barreiro, Olga, Harvard Medical School, Boston, Massachusetts, United States
  • Zhou, Jing, Brigham and Women's Hospital, Boston, Massachusetts, United States
Background

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a common genetic disorder marked by progressive cyst formation and significant disruption of tubular function. ADPKD is caused by mutations in either PKD1 or PKD2. Most efforts, however, have focused on the signaling pathways related to cystogenesis, little is known about cyst development and tubular function in live mouse model of the human disease. Endocytosis, is a process crucial for protein reabsorption, membrane turnover, and cellular signaling. In healthy kidneys, proximal tubules exhibit rapid and robust uptake of filtered solutes via endocytosis. Intravital imaging allows real-time visualization of these dynamic processes in vivo. Here we report the use of two-photon microscopy to study tubular function in an authentic mouse model of ADPKD.

Methods

We developed a live imaging platform using upright two-photon microscopy to visualize dextran uptake in the proximal tubules of Pkd1 +/null mouse, an ADPKD mouse line we previously established (Lu et al 2001). A fluorescent dextran tracer was administered via retro-orbital injection, and a custom imaging window was installed and used to stabilize the kidney for intravital imaging. Z-stacks were acquired at regular time intervals. Dextran uptake in the S1 segment of proximal tubules was quantified using line scan analysis in FIJI/ImageJ.

Results

We observed a clear time-dependent pattern of dextran uptake in the proximal tubules, with fluorescence intensity increasing over the first 20 minutes and gradually declining thereafter. This dynamic uptake profile was captured in a single Pkd1+/null mouse, demonstrating the feasibility of extended live imaging in an ADPKD model.

Conclusion

This study presents a novel approach for real-time, high-resolution imaging of fluid-phase endocytosis in a model of ADPKD kidney. The observed uptake dynamics may reflect altered endocytic capacity or metabolic regulation in cystic tubules, consistent with known disruptions in cellular trafficking and energy homeostasis in ADPKD. Importantly, this method was successfully applied in a Pkd1+/null mouse model, highlighting its potential for studying tubular function in advanced ADPKD and for evaluating therapeutic interventions in vivo.

Funding

  • NIDDK Support

Digital Object Identifier (DOI)