A novel tracer for in vivo optical imaging of fatty acid metabolism in the heart and brown adipose tissue

Multiplexed imaging is essential for the evaluation of substrate utilization in metabolically active organs, such as the heart and brown adipose tissue (BAT), where substrate preference changes in pathophysiologic states. Optical imaging provides a useful platform because of its low cost, high throughput and intrinsic ability to perform composite readouts. However, the paucity of probes available for in vivo use has limited optical methods to image substrate metabolism. Here, we present a novel near-infrared (NIR) free fatty acid (FFA) tracer suitable for in vivo imaging of deep tissues such as the heart. Using click chemistry, Alexa Fluor 647 DIBO Alkyne was conjugated to palmitic acid. Mice injected with 0.05 nmol/g bodyweight of the conjugate (AlexaFFA) were subjected to conditions known to increase FFA uptake in the heart (fasting) and BAT [cold exposure and injection with the β3 adrenergic agonist CL 316, 243(CL)]. Organs were subsequently imaged both ex vivo and in vivo to quantify AlexaFFA uptake. The blood kinetics of AlexaFFA followed a two-compartment model with an initial fast compartment half-life of 0.14 h and a subsequent slow compartment half-life of 5.2 h, consistent with reversible protein binding. Ex vivo fluorescence imaging after overnight cold exposure and fasting produced a significant increase in AlexaFFA uptake in the heart (58 ± 12%) and BAT (278 ± 19%) compared to warm/fed animals. In vivo imaging of the heart and BAT after exposure to CL and fasting showed a significant increase in AlexaFFA uptake in the heart (48 ± 20%) and BAT (40 ± 10%) compared to saline-injected/fed mice. We present a novel near-infrared FFA tracer, AlexaFFA, that is suitable for in vivo quantification of FFA metabolism and can be applied in the context of a low cost, high throughput, and multiplexed optical imaging platform.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:10

Enthalten in:

Scientific reports - 10(2020), 1 vom: 08. Juli, Seite 11209

Sprache:

Englisch

Beteiligte Personen:

Panagia, Marcello [VerfasserIn]
Yang, Jing [VerfasserIn]
Gale, Eric [VerfasserIn]
Wang, Huan [VerfasserIn]
Luptak, Ivan [VerfasserIn]
Chen, Howard H [VerfasserIn]
Patel, Dakshesh [VerfasserIn]
Croteau, Dominique [VerfasserIn]
Pimentel, David Richard [VerfasserIn]
Bachschmid, Markus Michael [VerfasserIn]
Colucci, Wilson S [VerfasserIn]
Ran, Chongzhao [VerfasserIn]
Sosnovik, David E [VerfasserIn]

Links:

Volltext

Themen:

0Z5B2CJX4D
138908-40-4
Dioxoles
Disodium (R,R)-5-(2-((2-(3-chlorophenyl)-2-hydroxyethyl)-amino)propyl)-1,3-benzodioxole-2,3-dicarboxylate
Fatty Acids, Nonesterified
Fluorescent Dyes
Fluorodeoxyglucose F18
Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

Anmerkungen:

Date Completed 21.12.2020

Date Revised 19.05.2022

published: Electronic

Citation Status MEDLINE

doi:

10.1038/s41598-020-68065-4

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM312190468