Abstract
Lipid species patterns are conserved within cells to maintain physicochemical properties of membranes and cellular functions. We present the lipidome, including sterols, glycerolipids (GLs), glycerophospholipids (GPLs), and sphingolipids (SLs), of primary ex vivo differentiated (I) white, (II) brite, and (III) brown adipocytes derived from primary preadipocytes isolated from (I) epididymal white, (II) inguinal white, and (III) intrascapular brown adipose tissue. Quantitative lipidomics revealed significantly decreased fractions of phosphatidylcholine (PC) and phosphatidylethanolamine (PE), with longer (C > 36) and more polyunsaturated species, as well as lower levels of cardiolipin (CL) in white than in brite and brown adipocytes. Together, the brite and brown lipidome was comparable and indicates differences in membrane lipid packing density compared with white adipocytes. Changes in ceramide species profile could be related to the degree of browning. Beta-adrenergic stimulation of brown adipocytes led to generation of saturated lyso-PC (LPC) increasing uncoupling protein (UCP) 1-mediated leak respiration. Application of stable isotope labeling showed that LPC formation was balanced by an increased de novo synthesis of PC.
Highlights
Mammalian adipose tissue (AT) can be categorized in white and brown AT
Preadipocytes derived from inguinal white AT (WAT) (iWAT), which are in this study referred as “brite” adipocytes, are a heterogeneous population of brite and white fat cells
Expression levels of genes characteristic for white adipocytes were comparable in iWAT-derived cells to either those of epididymal white AT (eWAT) (Lep) or intrascapular brown AT (iBAT) (Adcy5, transcription factor 21 (Tcf21)), arguing for their mixed phenotype
Summary
Mammalian adipose tissue (AT) can be categorized in white and brown AT. Adipocytes from white AT (WAT) store excess energy in the form of triacylglycerides (TGs) that can be released as free fatty acids (FAs) into the circulation when necessary. They represent globular cells with a single large lipid droplet [1]. Brown adipocytes contain several small lipid droplets and can generate heat to maintain a stable body temperature by nonshivering thermogenesis, which is mediated by uncoupling protein 1 (UCP1) [2]. In addition to white and brown adipocytes, mice and humans harbor inducible brown, known as brite or beige, adipocytes [3,4,5]. In inguinal WAT (iWAT), brite adipocytes can appear in response to cold exposure, providing an extra thermogenic capacity [6,7]
Sign-in/Register to view highlights & summary 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.
