Spatial Recruitment of Cardiolipins in White Adipose Tissue after Cold Stimulation is Independent of UCP1

ABSTRACT: Abstract Brown and brite adipocytes are the key cells performing uncoupling protein 1 (UCP1) dependent non-shivering thermogenesis (NST) induced by cold exposure. Several lipid species are associated to NST in brown and white adipose tissue. Studies investigating the association of the lipid profile with NST rely on the analysis of whole organ homogenates or on the differentiation of pre-adipocytes in vitro. These approaches have so far not addressed the heterogeneity of white adipose tissue. Aim of this study was to characterize the lipid composition of white adipose tissue on a region-specific level in an in vivo context. We applied MALDI mass spectrometry imaging (MALDI-MSI) in combination with immunohistochemistry and high-resolution mass spectrometry on sections of inguinal white adipose tissue of 129S6/SvEvTac and C57BL6/N-UCP1 knockout and wildtype mice acclimatized to cold to identify lipids specific to areas of UCP1 expression. Based on the analysis of cold exposed 129S6/SvEvTac mice we identified cardiolipins (CL) and diacylglycerols (DG) species to be specific for areas expressing UCP1 and triacylglycerols (TG) to be the main lipid class characteristic for UCP1 negative regions within inguinal white adipose tissue. Investigation of C57BL6/N-UCP1 knockout and wildtype mice housed at either room temperature or acclimatized to cold, demonstrated that CL content in white adipose tissue is increased upon cold stimulation, independent of UCP1. We introduce a MALDI-MSI based approach to identify lipids associated to thermogenic adipocytes in adipose tissues demonstrating a clear regional cold dependent upregulation of CL independent of UCP1.

INSTRUMENT(S): TripleTOF 6600

ORGANISM(S): Mus Musculus (ncbitaxon:10090)

SUBMITTER: Karin Kleigrewe  

PROVIDER: MSV000087164 | MassIVE | Wed Apr 07 02:04:00 BST 2021

REPOSITORIES: MassIVE