Depot-Specific Differences in Adipogenic Progenitor Abundance and Proliferative Response to High-Fat Diet

Abstract

White adipose tissue (fat) is the primary organ for energy storage and its regulation has serious implications on human health. Excess fat tissue causes significant morbidity, and adipose tissue dysfunction caused by excessive adipocyte hypertrophy has been proposed to play a significant role in the pathogenesis of metabolic disease. Studies in both humans and animal models show that metabolic dysfunction is more closely associated with visceral than subcutaneous fat accumulation. Here, we show that in mice fed a high-fat diet, visceral fat (VAT) grows mostly by hypertrophy and subcutaneous fat (SAT) by hyperplasia, providing a rationale for the different effects of specific adipose depots on metabolic health. To address whether depot expansion is controlled at the level of stem/progenitor cells, we developed a strategy to prospectively identify adipogenic progenitors (APs) from both depots. Clonogenic assays and in vivo bromodeoxyuridine (BrdU) studies show that APs are eightfold more abundant in SAT than VAT, and that AP proliferation is significantly increased in SAT but not VAT in response to high-fat diet. Our results suggest that depot-specific differences in AP abundance and proliferation underlie whether a fat depot expands by hypertrophy or hyperplasia, and thus may have important implications on the development of metabolic disease. In addition, we provide the first evidence that dietary inputs can modulate the proliferation of adipogenic progenitors in adults.

Specific collagen XVIII isoforms promote adipose tissue accrual via mechanisms determining adipocyte number and affect fat deposition

“…eWAT was excised and analyzed as described previously (21,52), with minor modifications. Tissues were minced in PBS and digested with collagenase (Worthington Biochemical Corporation) (1 mL/g of homogenized tissue) at 37°C for 2 h. Cells were collected by centrifugation at 200 × g for 10 min, and the floating adipocyte layer and supernatant discarded.…”

Ebf2 is a selective marker of brown and beige adipogenic precursor cells

“…S5A), whereas preadipose cells in postnatal BAT and WAT were Sca1 + (Fig. S5B) (28,29). Quantitative PCR (qPCR) analysis revealed that Pparγ and Zfp423, key adipocyte-lineage genes (30,31), were expressed at higher levels in Myf5 Cre (GFP) + ; Pdgfrα + cells relative to other sorted fractions (Fig.…”

Functionally Convergent White Adipogenic Progenitors of Different Lineages Participate in a Diffused System Supporting Tissue Regeneration

“…The following monoclonal primary antibodies were used: anti-CD31 (clones MEC13.3, Becton Dickenson, Mississauga, Canada, www.bd.com, and 390; Cedarlane Laboratories, Burlington, Canada, https://pilot.cedarlanelabs.com), anti-CD34 (clone RAM34; eBioscience), anti-CD45 (clone 30-F11; Becton Dickenson), anti-Sca-1 (clone D7; eBiosciences, San Diego, California, www.ebiosciences.com), and anti-a7 integrin (produced inhouse). The antibody dilutions were as previously reported [9,12]. Analysis was performed on LSRII (Becton Dickenson) equipped with three lasers.…”

“…In order to isolate NCderived adipocyte progenitors, we dissected and enzymatically dissociated the cephalic, flank, and perigonadal fat depots from WNT1-Cre/R26-YFP mice to separate the stromal vascular component. To identify prospective NC-derived adipocyte progenitors, we followed a flow cytometry strategy previously developed to identify WAT progenitors in mesodermal fat depots [9]. We first excluded cells from hematopoietic, endothelial, and myogenic lineages by gating the stromal vascular fraction (SVF) based on the expression of CD45 (hematopoietic), CD31 (endothelial), and a 7 integrin (skeletal/smooth muscle) ( Fig.…”

“…While the mesoderm has long been considered the only source of WAT, certain forms of WAT dystrophies, such as congenital infiltrating lipomatosis of the face (CIL-F) [6,7] and the Dunnigan-Kobberling syndrome [8] suggest the existence of different cellular mechanisms for cephalic versus trunk and limb adipogenesis. Recently, others and we have reported the existence of a population of mesenchymal progenitors residing in both WAT and skeletal muscle that contains virtually all the adipogenic activity of both tissues [9][10][11][12]. These cells are bipotent, are capable of producing both adipocytes and fibroblasts in vitro [11,12], and were consequently termed fibro/adipogenic progenitors (FAPs) [13].…”