Characterization and lineage tracing of a mouse adipose depot reveal properties conserved with human supraclavicular brown adipose tissue

Figures

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  Figure 1. Identification of a unique beige adipose tissue depot (A) Diagram of the ventral side of a mouse showing the position of the inguinal beige adipose tissue (ibAT) at the junction between the lower leg and the abdominal wall. L: lymph node. (B) Left: representative image showing the anatomical location of ibAT. White arrowheads indicate ibAT. Right: representative image showing the anatomical location of ibAT after dissecting away the iWAT. L: lymph node. White arrowheads indicate ibAT. Scale bar, 5 mm. (C) Representative images of isolated ibAT and interscapular BAT. Scale bar, 5 mm. (D) Representative H&E staining of histological sections from ibAT. Higher magnification images (right) of the areas indicated by black boxes (left). Scale bar, 100 μm. (E) Relative mitochondrial (mt) DNA content in iWAT, ibAT, and BAT assessed by qPCR and calculated from copy number of the mtDNA-encoded MtCO1 gene and the nuclear DNA-encoded Ndufv1 gene. Paired t test, n = 5 of each adipose depot from 5 different mice. (F and G) Quantification of the relative mRNA expression levels of thermogenetic genes in iWAT, ibAT, and BAT by quantitative reverse-transcription PCR (RT-qPCR). One-way ANOVA, n = 3…

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  Figure 2. ibAT maintains thermogenic activity through aging (A) Representative images of ibAT at different ages. Scale bar, 5 mm. (B) Representative images of ibAT at different ages. (C) Quantification of relative ibAT mass as a percentage of adjacent WAT mass. Student’s t test, n = 4 ibATs from 4 different mice. (D and E) Quantification of the relative mRNA expression levels of thermogenetic genes in iWAT, ibAT, and BAT of aged mice by RT-qPCR. One-way ANOVA, n = 4 of each adipose depot from 4 different mice. (F) Quantification of the relative mRNA expression levels of Npr3 in iWAT and ibAT of aged mice by RT-qPCR. Student’s t test, n = 4 of each adipose depot from 4 different mice. (G) Quantification of the relative mRNA expression levels of Trk3 in iWAT, ibAT, and BAT of aged mice by RT-qPCR. One-way ANOVA, n = 4 of each adipose depot from 4 different mice. (H) Measurements of OCRs of ibAT from aged mice. One-way ANOVA, n = 3 of each adipose depot from 3 different mice. (I) Representative images of immunofluorescence staining for UCP1 and ATP5K in ibAT. Scale bar, 100 μm. Data are represented as mean ± SEM. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001. See also Figure S1.

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  Figure 3. Lineage tracing of Trpv1 in ibAT (A) Representative images of the indicated adipose tissue from Trpv1-Cre-Confetti mice. Scale bar, 50 μm. (B) Representative images of cultured SVF isolated from iWAT from indicated mice. Scale bar, 500 μm. (C) Representative images of the ex vivo differentiated iWAT adipocytes from Trpv1-Cre-Confetti mice. Scale bar, 500 μm. (D) Representative fluorescence imaging of the ex vivo differentiated iWAT adipocytes from Prx1-Cre-Confetti mice. Scale bar, 500 μm. See also Figure S1.

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  Figure 4. ibAT traces to the Prx1 + lineage (A) Representative images of whole-mount adipose tissue isolated from Prx1-Cre-Confetti mice. Scale bar, 50 μm. (B) Representative images of whole-mount adipose tissue isolated from Myf5-Cre-Confetti mice. Scale bar, 50 μm. (C) Representative images of histological sections of scBAT from Prx1-Cre-Confetti and Myf5-Cre-Confetti mice. Scale bar, 50 μm. (D) Quantification of the relative mRNA expression levels of PRX1 and TBX1 from an immortalized brown adipose progenitor originating from human infant BAT and human adult scBAT. Student’s t test in 2 cell lines n = 4 replicates. Data are represented as mean ± SEM. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001. See also Figures S1 and S2.