Reconstructing human Brown Fat developmental trajectory in vitro

Abstract

Brown adipocytes represent a specialized type of mammalian adipocytes able to uncouple nutrient catabolism from ATP generation to dissipate energy as heat. They play an important role in mammals, allowing non-shivering thermogenesis to regulate body temperature in response to cold exposure. In humans, the brown fat tissue is composed of small discrete depots found mostly throughout the neck and trunk region. Increasing brown fat activity either with drug treatment or cell therapy is considered a potential approach for the treatment of metabolic syndrome and obesity. The recent development of in vitro differentiation strategies relying on human pluripotent stem cells (hPSCs) offers the possibility to produce unlimited amounts of brown adipocytes. A strategy efficiently applied to several tissues is to recapitulate step by step the development of the tissue of interest by exposing hPSCs to the signaling cues used during normal embryonic development. However, this strategy has proven difficult to implement for brown fat as the development of this tissue is poorly understood. Here, we first used single cell RNA sequencing to characterize the development of interscapular brown fat in mouse. Our analysis identified a previously unrecognized population of brown adipocytes precursors characterized by expression of the transcription factor GATA6. We show that this precursor population can be efficiently generated from paraxial mesoderm precursors differentiated in vitro from hPSCs by modulating the signaling pathways identified in our transcriptomic analysis. These precursors can in turn be efficiently converted into functional brown adipocytes which can respond to adrenergic stimuli by increasing their metabolism resulting in heat production.

The cellular landscape of the endochondral bone during the transition to extrauterine life

“…SCENIC accurately captured biologically relevant regulons in chondrogenic [Sox9(+), Sox5(+); ChC and ACP], osteogenic [Runx2(+), Sp7(+), Dlx5(+); OsC] and adipogenic [Pparg(+), Gata6(+), Prdm6(+); AFP and GFP] clusters (Supplementary figure 10). Concerning the latter differentiation program, Pparg is a key adipogenic regulator, while Gata6 has been recently associated with brown adipogenesis, 60 in agreement with our GO analysis. Finally, GWAS studies have linked PRDM6 to obesity and osteoporosis, 61 while another family member, Prdm16 , has been implicated in brown fat differentiation in early myoblast progenitors 62 .…”

The cellular landscape of the endochondral bone during the transition to extrauterine life

“…S10). Concerning the latter differentiation program, Pparg is a key adipogenic regulator, while Gata6 has been recently associated to brown adipogenesis (Rao et al, 2022), in agreement with our GO analysis. Finally, GWAS studies have linked PRDM6 to obesity and osteoporosis (Hu et al, 2018), and another family member, Prdm16, has been implicated in brown fat differentiation in early myoblast progenitors (Seale et al, 2008;Van Nguyen et al, 2020).…”

“…The copyright holder for this this version posted November 2, 2023. ; https://doi.org/10.1101/2023.07.18.549529 doi: bioRxiv preprint adipogenesis (Rao et al, 2022), in agreement with our GO analysis. Finally, GWAS studies have linked PRDM6 to obesity and osteoporosis (Hu et al, 2018), and another family member, Prdm16, has been implicated in brown fat differentiation in early myoblast progenitors (Seale et al, 2008;Van Nguyen et al, 2020).…”

In Vitro Differentiation of Beige/Brown Adipocytes for the Treatment of Metabolic Diseases

“…Bioinformatics analyzes suggest that these progenitors give rise to brown adipocyte precursors which express Ebf2 and Pparγ. These precursors give rise to a population of embryonic brown adipocytes expressing Ucp1 and Cidea which is first detected at E15.5 [29,30]. Our work also identified Gata6 as a selective marker transiently expressed in the brown adipocyte lineage.…”

“…We performed a single cell RNA sequencing analysis [29] of the dorsal tissue of developing mouse embryos and identified a cluster, at E11.5, containing fibroblastic progenitors of bone, cartilage, smooth muscles, connective tissues, dermis and brown adipocytes which express Pdgfr-α and Hic1. Bioinformatics analyzes suggest that these progenitors give rise to brown adipocyte precursors which express Ebf2 and Pparγ.…”