Intravital imaging-based analysis tools for vessel identification and assessment of concurrent dynamic vascular events

• Published in: Nature communications Vol. 9; no. 1; pp. 2746 - 10
• Main Authors: Honkura, Naoki, Richards, Mark, Laviña, Bàrbara, Sáinz-Jaspeado, Miguel, Betsholtz, Christer, Claesson-Welsh, Lena
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 16.07.2018; Nature Publishing Group; Nature Portfolio
• Subjects: 13; 13/1; 14; 14/69; 631/1647/245; 631/443/1338/2729; 631/80/79/1987; 64; 64/110; 64/60; Animals; Blood flow; Blood Flow Velocity - drug effects; Blood Flow Velocity - physiology; Blood vessels; Blood Vessels - anatomy & histology; Blood Vessels - diagnostic imaging; Blood Vessels - drug effects; Blood Vessels - physiology; Capillaries; Claudin-5 - genetics; Claudin-5 - metabolism; Cytology; Dextran; Erythrocytes; Female; Flow velocity; Fluorescence; Gene Expression; Genes, Reporter; Green fluorescent protein; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; Humanities and Social Sciences; Image analysis; Image processing; Injections, Intradermal; Leakage; Medicin och hälsovetenskap; Mice; Mice, Inbred C57BL; Mice, Transgenic; Microscopy, Fluorescence, Multiphoton - instrumentation; Microscopy, Fluorescence, Multiphoton - methods; Molecular Imaging - instrumentation; Molecular Imaging - methods; Morphology; multidisciplinary; Parameter identification; Permeability; Promoter Regions, Genetic; Proteins; Science; Science (multidisciplinary); Vascular endothelial growth factor; Vascular Endothelial Growth Factor A - administration & dosage
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-04929-8

The vasculature undergoes changes in diameter, permeability and blood flow in response to specific stimuli. The dynamics and interdependence of these responses in different vessels are largely unknown. Here we report a non-invasive technique to study dynamic events in different vessel categories by multi-photon microscopy and an image analysis tool, RVDM (relative velocity, direction, and morphology) allowing the identification of vessel categories by their red blood cell (RBC) parameters. Moreover, Claudin5 promoter-driven green fluorescent protein (GFP) expression is used to distinguish capillary subtypes. Intradermal injection of vascular endothelial growth factor A (VEGFA) is shown to induce leakage of circulating dextran, with vessel-type-dependent kinetics, from capillaries and venules devoid of GFP expression. VEGFA-induced leakage in capillaries coincides with vessel dilation and reduced flow velocity. Thus, intravital imaging of non-invasive stimulation combined with RVDM analysis allows for recording and quantification of very rapid events in the vasculature. Different stimuli can induce dynamic changes in blood flow velocity, vessel diameter and permeability. Here the authors develop a multi-photon microscopy-based image analysis tool allowing the identification of vessels and the assessment of rapid changes in large vascular networks.