title: Adipose lineage specification of bone marrow-derived myeloid cells.
abstract: We have reported the production of white adipocytes in adipose tissue from hematopoietic progenitors arising from bone marrow. However, technical challenges have hindered detection of this adipocyte population by certain other laboratories. These disparate results highlight the need for sensitive and definitive techniques to identify bone marrow progenitor (BMP)-derived adipocytes. In these studies we exploited new models and methods to enhance detection of this adipocyte population. Here we showed that confocal microscopy with spectrum acquisition could effectively identify green fluorescent protein (GFP) positive BMP-derived adipocytes by matching their fluorescence spectrum to that of native GFP. Likewise, imaging flow cytometry made it possible to visualize intact unilocular and multilocular GFP-positive BMP-derived adipocytes and distinguished them from non-fluorescent adipocytes and cell debris in the cytometer flow stream. We also devised a strategy to detect marker genes in flow-enriched adipocytes from which stromal cells were excluded. This technique also proved to be an efficient means for detecting genetically labeled adipocytes and should be applicable to models in which marker gene expression is low or absent. Finally, in vivo imaging of mice transplanted with BM from adipocyte-targeted luciferase donors showed a time-dependent increase in luciferase activity, with the bulk of luciferase activity confined to adipocytes rather than stromal cells. These results confirmed and extended our previous reports and provided proof-of-principle for sensitive techniques and models for detection and study of these unique cells.
authors.affiliation: Gates Center for Stem Cell Biology and Regenerative Medicine; University of Colorado Anschutz Medical Campus; Aurora, CO USA ; Department of Medicine; University of Colorado Anschutz Medical Campus; Aurora, CO USA.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Majka
authors.forename: Heidi L
authors.initials: HL
authors.lastname: Miller
authors.forename: Timothy
authors.initials: T
authors.lastname: Sullivan
authors.forename: Paul F
authors.initials: PF
authors.lastname: Erickson
authors.forename: Raymond
authors.initials: R
authors.lastname: Kong
authors.forename: Mary
authors.initials: M
authors.lastname: Weiser-Evans
authors.forename: Raphael
authors.initials: R
authors.lastname: Nemenoff
authors.forename: Radu
authors.initials: R
authors.lastname: Moldovan
authors.forename: Shelley A
authors.initials: SA
authors.lastname: Morandi
authors.forename: James A
authors.initials: JA
authors.lastname: Davis
authors.forename: Dwight J
authors.initials: DJ
authors.lastname: Klemm
keywords: adipocyte; bone marrow; confocal microscopy; imaging flow cytometry; in vivo imaging; progenitor cell; spectral analysis