Flicker-assisted localization microscopy reveals altered mitochondrial architecture in hypertension

Area of Science:

• Cell Biology
• Mitochondrial Biology
• Physiology

Background:

• Mitochondrial morphology is crucial for cellular function and disease pathogenesis.
• Quantifying complex mitochondrial structures in live cells and tissues remains challenging.
• Existing methods struggle to resolve individual mitochondria within dense clusters.

Purpose of the Study:

• To develop a novel microscopy technique for high-resolution quantification of mitochondrial morphology in live cells.
• To investigate alterations in mitochondrial architecture associated with hypertension.
• To establish Flicker-assisted Localization Microscopy (FaLM) as a tool for studying mitochondrial dynamics.

Main Methods:

• Developed Flicker-assisted Localization Microscopy (FaLM) using a rapidly-partitioning fluorophore to visualize mitochondrial membrane potential flickers.
• Analyzed pixel-by-pixel covariance of spatio-temporal fluorescence changes to resolve individual mitochondria.
• Applied FaLM to vascular myocytes from normotensive and hypertensive animal models.

Main Results:

• FaLM successfully resolved individual mitochondria, revealing that apparent size variations were due to packing density.
• Normotensive animals exhibited small, spherical or rod-shaped mitochondria.
• Hypertensive animals displayed larger, more densely clustered mitochondria occupying greater cellular volume.

Conclusions:

• FaLM provides a convenient and effective method for detailed discrimination of mitochondrial architecture in live cells.
• Mitochondrial alterations, including increased size and clustering, are associated with hypertension.
• These observed mitochondrial changes may play a significant role in the development or progression of hypertension.