Single-Cell Profiling of Fatty Acid Uptake Using Surface-Immobilized Dendrimers

Abstract

We present a chemical approach to profile fatty acid uptake in single cells. We use azide-modified analogues to probe the fatty acid influx and surface-immobilized dendrimers with dibenzocyclooctyne (DBCO) groups for detection. A competition between the fatty acid probes and BHQ2-azide quencher molecules generates fluorescence signals in a concentration-dependent manner. By integrating this method onto a microfluidics-based multiplex protein analysis platform, we resolved the relationships between fatty acid influx, oncogenic signaling activities, and cell proliferation in single glioblastoma cells. We found that p70S6K and 4EBP1 differentially correlated with fatty acid uptake. We validated that cotargeting p70S6K and fatty acid metabolism synergistically inhibited cell proliferation. Our work provided the first example of studying fatty acid metabolism in the context of protein signaling at single-cell resolution and generated new insights into cancer biology.

Recent advances in microfluidics-based bioNMR analysis

“…As summarized above, μNMR systems allow the detection of minimal samples in a non-invasive way at an atomic resolution, which is significantly advantageous over other analytical methods (such as microfluidics-based fluorescence systems, 100 Raman systems, 101 mass spectroscopy systems, 102 etc.). However, current μNMR systems also show apparent limitations in terms of simplicity, sensitivity, throughput and others.…”

13C-SpaceM: Spatial single-cell isotope tracing reveals heterogeneity ofde novofatty acid synthesis in cancer

“…For example, a metabolic sensor based on the malonyl-CoA responsive Bacillus subtilis transcriptional repressor, FapR, was developed to determine the activity of FASN in live cells 28 . Another approach used surface-immobilized dendrimers to evaluate fatty acid uptake on a single cell level 29 . Furthermore, a recent study applied dielectric barrier discharge ionization (DBDI) on single cells to determine alterations in lipid metabolism upon ACLY inhibition in pancreatic cancer cells 30 .…”

Phase transfer of fatty acids into ultrasmall nanospheres for colorimetric detection of lipase and albumin

“…1,2 Detection of fatty acids is crucial in fundamental and applied research. 3,4 Conventional instrumental methods include gas chromatography (GC), 5,6 liquid chromatography (LC), 7 capillary electrophoresis (CE), 8 and mass spectroscopy. 9,10 However, the lack of chromophores in fatty acids makes them optically silent in the UV-visible light range.…”