Abstract: SA-PO150

Optical Analysis of Mitochondrial Dynamics and Function in Renal Physiology and Pathology In Vivo Using Metabolic Biosensor Transgenic Zebrafish

Session Information

Category: Nutrition, Inflammation, and Metabolism

  • 1401 Nutrition, Inflammation, Metabolism

Authors

  • Sugano, Yuya, Massachusetts General Hospital, Charlestown, Massachusetts, United States
  • Keller, Jacob Pearson, Janelia Research Campus, Ashburn, Virginia, United States
  • Tomar, Ritu, Massachusetts General Hospital, Charlestown, Massachusetts, United States
  • Siegfried, Hugo Luc jules, Massachusetts General Hospital, Charlestown, Massachusetts, United States
  • Looger, Loren, Janelia Research Campus, Ashburn, Virginia, United States
  • Drummond, Iain A., Massachusetts General Hospital , Charlestown, Massachusetts, United States
Background

Accumulating amounts of evidence suggest that mitochondria play a major role in maintenance of renal function and pathogenesis of kidney diseases. Despite the apparent importance, however, little is known about mechanisms by which altered mitochondrial function leads to development of renal disease due to lack of appropriate tools. Mitochondria are a dynamic organelle that actively changes its shape, number and site of residence, thereby making it critical to analyze them in vivo. In order to establish in vivo tools to study mitochondria, we applied the genetically encoded biosensor technology to the zebrafish, an optically accessible and genetically tractable model system.

Methods

A transgenic zebrafish line incorporating a mitochondria targeted redox sensor (mitoGrx1-roGFP2) under the UAS effector element was generated. By crossing this UAS effector line into Gal4 driver lines with podocin and cdh17 promoter [Tg(podo:Gal4) and Tg(cdh17:Gal4)], mitoGrx1-roGFP2 was expressed in glomerular podocytes and tubular epithelial cells, respectively, in the pronephros. Live imaging of the transgenic zebrafish was performed by sequential excitation at 405 nm and 488 nm for ratiometric measurements.

Results

We found that mitochondrial structure and dynamics in podocytes can be imaged in living zebrafish by two-photon microscopy. Time lapse imaging of Tg(podo:Gal4, UAS:mitoGrx1-roGFP2) demonstrated that mitochondria are stationary in pronephric podocytes. Upon exposure to a nephrotoxic antibiotic, puromycin aminonucleoside, mitochondria appeared to relocalize to primary and secondary processes from the cell body. Furthermore, ratiometric measurements of mitoGrx1-roGFP2 reported changes in oxidative stress levels in mitochondria in renal tubular epithelia in response to tert butyl hydroperoxide.

Conclusion

These transgenic zebrafish represent a novel tool to investigate mitochondrial structure and function in vivo. In addition, transgenic zebrafish with biosensors for other metabolic parameters, such as glucose, are also being validated. These transgenic zebrafish offer a versatile and accessible in vivo system to study mitochondrial dynamics and activity as well as their associated metabolism in the kidney in health and disease.

Funding

  • NIDDK Support