Abstract
Raman spectroscopic imaging was used to investigate the uptake of oxidized LDLs (oxLDLs) by human macrophages. To better understand the endocytic pathway and the intracellular fate of modified lipoproteins is of foremost interest with regard to the development of atherosclerotic plaques. To obtain information on the storage process of lipids caused by oxLDL uptake, Raman spectroscopic imaging was used because of its unique chemical specificity, especially for lipids. For the present study, a protocol was established to incorporate deuterated tripalmitate into oxLDL. Subsequently, human THP-1 macrophages were incubated for different time points and their chemical composition was analyzed using Raman spectroscopic imaging. β-Carotene was found to be a reliable marker molecule for the uptake of lipoproteins into macrophages. In addition, lipoprotein administration led to small endocytic vesicles with different concentrations of deuterated lipids within the cells. For the first time, the translocation of deuterated lipids from endocytic vesicles into lipid droplets over time is reported in mature human THP-1 macrophages.
Highlights
Raman spectroscopic imaging was used to investigate the uptake of oxidized LDLs by human macrophages
For the first time, imaging of the endocytic uptake of oxidized LDLs (oxLDLs) and the distribution of LDL-associated fatty acids by human macrophages using Raman spectroscopy
Along with the storage of -carotene in lipid droplets, localized compartments close to the nucleus and endoplasmic reticulum were found. These compartments were found in both cells incubated with deuterated tripalmitate (d-TP)-loaded oxLDL and cells incubated with unloaded oxLDL, which served as controls, but were not present in every cell
Summary
Raman spectroscopic imaging was used to investigate the uptake of oxidized LDLs (oxLDLs) by human macrophages. To obtain information on the storage process of lipids caused by oxLDL uptake, Raman spectroscopic imaging was used because of its unique chemical specificity, especially for lipids. Human THP-1 macrophages were incubated for different time points and their chemical composition was analyzed using Raman spectroscopic imaging. -Carotene was found to be a reliable marker molecule for the uptake of lipoproteins into macrophages. Lipoprotein administration led to small endocytic vesicles with different concentrations of deuterated lipids within the cells. The translocation of deuterated lipids from endocytic vesicles into lipid droplets over time is reported in mature human THP-1 macrophages.—Stiebing, C., L. Raman imaging of macrophages incubated with triglycerideenriched oxLDL visualizes translocation of lipids between endocytic vesicles and lipid droplets.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
