Detection of dual-gene expression in arteries using an optical imaging method

Area of Science:

• Biomedical Imaging
• Molecular Biology
• Vascular Biology

Background:

• Monitoring transgene expression in vivo is crucial for gene therapy and research.
• Existing methods may have limitations in sensitivity or specificity for vascular applications.
• Optical imaging offers a non-invasive approach to visualize biological processes.

Purpose of the Study:

• To evaluate an optical imaging method for detecting vascular expression of green fluorescent protein (GFP) and red fluorescent protein (RFP) in vivo.
• To assess the simultaneous detection of concurrently expressed GFP and RFP using a dual-promoter lentiviral vector.
• To validate the method's ability to monitor transgene expression and localization in targeted arteries.

Main Methods:

• Utilized a charge-coupled device camera, fiber optic probe, and optical filters for fluorescence detection.
• Employed dual-promoter lentiviral vectors for concurrent GFP and RFP expression in animal arterial models.
• Administered local delivery of vectors to target arteries, with nonfluorescent protein transduction in contralateral arteries as sham controls.

Main Results:

• Distinct areas of bright fluorescence for GFP and RFP were observed along target arteries upon excitation.
• No exogenous fluorescence was detected in control arteries, confirming specificity.
• Signal intensities from transduced arteries significantly exceeded the autofluorescence baseline.
• In vivo transgene expression was confirmed using confocal microscopy.

Conclusions:

• An optical imaging method can effectively detect and distinguish vascular expression of two distinct fluorescent proteins (GFP and RFP) in vivo.
• This technique allows for the concurrent monitoring of multiple transgene expressions and their localization within the vasculature.
• The developed method holds potential for advancing gene therapy research and vascular biology studies.