In vivo fluorescence lifetime imaging captures metabolic changes in macrophages during wound responses in zebrafish [article]

Veronika Miskolci, Kelsey Tweed, Michael Lasarev, Emily C Britt, Courtney E McDougal, Alex J Walsh, Jing Fan, John-Demian Sauer, Melissa Skala, Anna Huttenlocher
2020 bioRxiv   pre-print
The effector functions of macrophages across the spectrum of activation states in vitro are linked to profound metabolic rewiring. However, the metabolism of macrophages remains poorly characterized in vivo. To assess changes in the intracellular metabolism of macrophages in their native inflammatory microenvironment, we employed two-photon fluorescence lifetime imaging microscopy (FLIM) of metabolic coenzymes NAD(P)H and FAD. We found that pro-inflammatory activation of macrophages in vivo was
more » ... associated with a decrease in the optical redox ratio [NAD(P)H/(NAD(P)H+FAD)] relative to a pro-resolving population during both infected and sterile inflammation. FLIM also resolved temporal changes in the optical redox ratio and lifetime variables of NAD(P)H in macrophages over the course of sterile inflammation. Collectively, we show that non-invasive and label-free imaging of autofluorescent metabolic coenzymes is sensitive to dynamic changes in macrophage activation in interstitial tissues. This imaging-based approach has broad applications in immunometabolism by probing in real time the temporal and spatial metabolic regulation of immune cell function in a live organism.
doi:10.1101/2020.06.16.153361 fatcat:v6qr3pyuuncwvlcbi24bnidtrq