title: Differential Hematopoietic Activity in White Adipose Tissue Depending on its Localization.
abstract: White adipose tissue (WAT) can be found in different locations in the body, and these different adipose deposits exhibit specific physiopathological importance according to the subcutaneous or abdominal locations. We have shown previously the presence of functional hematopoietic stem/progenitor cells (HSPC) in subcutaneous adipose tissue (SCAT). These cells exhibit a specific hematopoietic activity that contributes to the renewal of the immune cell compartment within this adipose deposit. In this study, we investigated whether HSPC can be found in visceral adipose tissue (VAT) and whether a putative difference in in situ hematopoiesis may be related to anatomical location and to site-specific immune cell content in VAT compared to SCAT. Therein, we identified for the first time the presence of HSPC in VAT. Using both in vitro assays and in vivo competitive repopulation experiments with sorted HSPC from VAT or SCAT, we showed that the hematopoietic activity of HSPC was lower in VAT, compared to SCAT. In addition, this altered hematopoietic activity of HSPC in VAT was due to their microenvironment, and may be related to a specific combination of secreted factors and extracellular matrix molecules expressed by adipose derived stromal cells. Our results indicate that WAT specific hematopoietic activity may be generalized to all adipose deposits, although with specificity according to the fat pad location. Considering the abundance of WAT in the body, this emphasizes the potential importance of this hematopoietic activity in physiopathological situations.
authors.affiliation: CNRS UMR 5273, STROMALab, BP 84225, Toulouse, France.|Université de Toulouse 3, UPS, BP 84225, Toulouse, France.|INSERM U1031, BP 84225, Toulouse, France.|EFS Pyrénées-Méditerranée, BP 84225, Toulouse, France.
authors.forename: Elodie
authors.initials: E
authors.lastname: Luche
authors.affiliation: CNRS UMR 5273, STROMALab, BP 84225, Toulouse, France.|Université de Toulouse 3, UPS, BP 84225, Toulouse, France.|INSERM U1031, BP 84225, Toulouse, France.|EFS Pyrénées-Méditerranée, BP 84225, Toulouse, France.
authors.forename: Coralie
authors.initials: C
authors.lastname: Sengenès
authors.affiliation: CNRS UMR 5273, STROMALab, BP 84225, Toulouse, France.|Université de Toulouse 3, UPS, BP 84225, Toulouse, France.|INSERM U1031, BP 84225, Toulouse, France.|EFS Pyrénées-Méditerranée, BP 84225, Toulouse, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Arnaud
authors.affiliation: CNRS UMR 5273, STROMALab, BP 84225, Toulouse, France.|Université de Toulouse 3, UPS, BP 84225, Toulouse, France.|INSERM U1031, BP 84225, Toulouse, France.|EFS Pyrénées-Méditerranée, BP 84225, Toulouse, France.|Laboratoire d'Hématologie, TSA 50032, Toulouse, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Laharrague
authors.affiliation: CNRS UMR 5273, STROMALab, BP 84225, Toulouse, France.|Université de Toulouse 3, UPS, BP 84225, Toulouse, France.|INSERM U1031, BP 84225, Toulouse, France.|EFS Pyrénées-Méditerranée, BP 84225, Toulouse, France.
authors.forename: Louis
authors.initials: L
authors.lastname: Casteilla
authors.affiliation: CNRS UMR 5273, STROMALab, BP 84225, Toulouse, France.|Université de Toulouse 3, UPS, BP 84225, Toulouse, France.|INSERM U1031, BP 84225, Toulouse, France.|EFS Pyrénées-Méditerranée, BP 84225, Toulouse, France.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Cousin
mesh_terms: D000818:Animals; D002450:Cell Communication; D019070:Cell Lineage; D049109:Cell Proliferation; D006411:Hematopoiesis, Extramedullary; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000276:immunology / Q000502:physiology*; D050152:Intra-Abdominal Fat / Q000166:cytology / Q000276:immunology / Q000502:physiology*; D008297:Male; D008810:Mice, Inbred C57BL; D010641:Phenotype; D055153:Stem Cell Niche; D050151:Subcutaneous Fat / Q000166:cytology / Q000276:immunology / Q000502:physiology*