title: Transcriptional Networks in Single Perivascular Cells Sorted from Human Adipose Tissue Reveal a Hierarchy of Mesenchymal Stem Cells.
abstract: Adipose tissue is a rich source of multipotent mesenchymal stem-like cells, located in the perivascular niche. Based on their surface markers, these have been assigned to two main categories: CD31-/CD45-/CD34+/CD146-cells (adventitial stromal/stem cells [ASCs]) and CD31-/CD45-/CD34-/CD146+cells (pericytes [PCs]). These populations display heterogeneity of unknown significance. We hypothesized that aldehyde dehydrogenase (ALDH) activity, a functional marker of primitivity, could help to better define ASC and PC subclasses. To this end, the stromal vascular fraction from a human lipoaspirate was simultaneously stained with fluorescent antibodies to CD31, CD45, CD34, and CD146 antigens and the ALDH substrate Aldefluor, then sorted by fluorescence-activated cell sorting. Individual ASCs (n = 67) and PCs (n = 73) selected from the extremities of the ALDH-staining spectrum were transcriptionally profiled by Fluidigm single-cell quantitative polymerase chain reaction for a predefined set (n = 429) of marker genes. To these single-cell data, we applied differential expression and principal component and clustering analysis, as well as an original gene coexpression network reconstruction algorithm. Despite the stochasticity at the single-cell level, covariation of gene expression analysis yielded multiple network connectivity parameters suggesting that these perivascular progenitor cell subclasses possess the following order of maturity: (a) ALDHbrASC (most primitive); (b) ALDHdimASC; (c) ALDHbrPC; (d) ALDHdimPC (least primitive). This order was independently supported by specific combinations of class-specific expressed genes and further confirmed by the analysis of associated signaling pathways. In conclusion, single-cell transcriptional analysis of four populations isolated from fat by surface markers and enzyme activity suggests a developmental hierarchy among perivascular mesenchymal stem cells supported by markers and coexpression networks. Stem Cells 2017;35:1273-1289.
authors.affiliation: Department of Orthopaedic Surgery and Broad Stem Cell Center, University of California at Los Angeles, California, USA.|Department of Medicine, University of Indiana, Indianapolis, Indiana, USA.
authors.forename: W Reef
authors.identifier: 0000-0002-4542-8444
authors.initials: WR
authors.lastname: Hardy
authors.affiliation: Department of Ophthalmology, IUPUI, Indianapolis, Indiana, USA.
authors.forename: Nicanor I
authors.initials: NI
authors.lastname: Moldovan
authors.affiliation: Department of Ophthalmology, IUPUI, Indianapolis, Indiana, USA.
authors.forename: Leni
authors.initials: L
authors.lastname: Moldovan
authors.affiliation: Fluidigm Corporation, South San Francisco, California, USA.
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Livak
authors.affiliation: Fluidigm Corporation, South San Francisco, California, USA.
authors.forename: Krishna
authors.initials: K
authors.lastname: Datta
authors.affiliation: Thomas Jefferson University Hospitals, Philadelphia, Pennsylvania, USA.
authors.forename: Chirayu
authors.initials: C
authors.lastname: Goswami
authors.affiliation: Department of Orthopaedic Surgery and Broad Stem Cell Center, University of California at Los Angeles, California, USA.|BD Biosciences, San Diego, California.
authors.forename: Mirko
authors.initials: M
authors.lastname: Corselli
authors.affiliation: Department of Medicine, University of Indiana, Indianapolis, Indiana, USA.
authors.forename: Dmitry O
authors.initials: DO
authors.lastname: Traktuev
authors.affiliation: Department of Orthopaedic Surgery and Broad Stem Cell Center, University of California at Los Angeles, California, USA.|MRC Centre for Regenerative Medicine, University of Edinburgh, Scotland, United Kingdom.
authors.forename: Iain R
authors.initials: IR
authors.lastname: Murray
authors.affiliation: Department of Orthopaedic Surgery and Broad Stem Cell Center, University of California at Los Angeles, California, USA.|MRC Centre for Regenerative Medicine, University of Edinburgh, Scotland, United Kingdom.
authors.forename: Bruno
authors.initials: B
authors.lastname: Péault
authors.affiliation: Department of Medicine, University of Indiana, Indianapolis, Indiana, USA.
authors.forename: Keith
authors.initials: K
authors.lastname: March
mesh_terms: D000273:Adipose Tissue / Q000166:cytology*; D000444:Aldehyde Dehydrogenase / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics; D019070:Cell Lineage; D005260:Female; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D053263:Gene Regulatory Networks; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism*; D008875:Middle Aged; D020286:Pericytes / Q000166:cytology; D059010:Single-Cell Analysis
chemical_list: D000444:Aldehyde Dehydrogenase
keywords: Adipose tissue; Mesenchymal stem cells; Pericyte; Single cell transcriptome; Tunica adventitia