Imaging In Mice With Fluorescent Proteins: From Macro To Subcellular

Area of Science:

• In vivo imaging
• Cell biology
• Biophotonics

Background:

• Whole-body imaging in small animals is crucial for biological research.
• Brighter, red-shifted fluorescent proteins enhance imaging sensitivity by minimizing tissue absorption and scatter.
• The novel Katushka protein offers superior brightness for red-shifted fluorescence (>620 nm).

Approach:

• Utilized red-shifted fluorescent proteins for enhanced whole-body imaging sensitivity.
• Employed dual-color labeling (green fluorescent protein in nucleus, red fluorescent protein in cytoplasm) to track cancer cell dynamics in real-time within mouse blood vessels.
• Developed a three-color animal model (GFP-expressing mice with dual-color cancer cells) for in vivo imaging of cancer cell/stromal cell interactions and drug response.

Key Points:

• Demonstrated real-time imaging of cancer cell extravasation, showing cytoplasmic processes leading nuclear movement and deformation.
• Observed cancer cell trafficking within lymphatic vessels.
• Enabled visualization of subcellular dynamics, including nuclear and cytoplasmic behavior, in live mice.

Conclusions:

• Advanced fluorescent proteins, like Katushka, significantly improve non-invasive macro and micro imaging capabilities in vivo.
• Real-time, multi-color imaging provides unprecedented insights into cancer cell behavior and interactions.
• These advancements pave the way for the new field of in vivo cell biology.