High-throughput proteomics uncovers exercise training and type 2 diabetes–induced changes in human white adipose tissue

Figures

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  Fig. 1.. High-throughput proteome analysis of human scWAT. (A) Graphic illustration of the study design. (B) Proteomics workflow from sampling and lysis of scWAT to analysis. (C) Number of scWAT proteins quantified per sample in each of the three groups. (D) Dynamic range plot of ranked protein abundance (log10 intensity) showing relevant adipocyte-specific markers (blue dots) and blood contaminants (red dots). (E) Principal component (PC) analysis plot of component 2 (x axis) and component 3 (y axis). Dots are colored by group.

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  Fig. 2.. Baseline proteome differences in scWAT from lean, obese, and T2D individuals. (A) Volcano plot showing baseline (pre) comparison of the WAT proteome between T2D and lean individuals (FDR < 10%). Most regulated proteins are highlighted. (B) Profile plot of significant T2D-lean regulated proteins. Dots connected by a line represent the profile of protein. Proteins with a distinct profile are highlighted in red and blue. (C) Boxplot of highlighted proteins with distinct profile curves between groups. (D and E) GO biological processes (GOBP) and cellular components (GOCC) enrichment analysis. Gene ratios of overlapping terms between T2D-obese (B), obese-lean (C) (y axis), and T2D-lean (x axis) are shown. Dots are colored by adjusted P value and size is based on the number of proteins in the enriched category.

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  Fig. 3.. Correlation of clinical parameters with scWAT proteins. (A) Correlation analysis of significantly regulated proteins at baseline with five clinical parameters. −Log10 (P value) on y axis. Most significant proteins are highlighted. (B and C) Kendall’s rank correlation of ANXA3 and CD14 protein abundance (log2 intensity, y axis) and GIR (mg/min/m2). (D) Kendall’s rank correlation of MIF and HbA1c (mmol/mol). Kendall’s τ coefficient and P value are shown.

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  Fig. 4.. Effects of exercise training on the human scWAT. (A) Volcano plot of group-wise log2 fold changes post- versus pretraining. Significant proteins are highlighted (FDR < 10%). (B) Selected representative GOCC terms significantly changing with exercise training in the lean and obese group. (C) Selected representative GOCC and GOBP terms significantly changing with exercise training in the T2D group. (D and E) Boxplot of FTL and FTH1 protein abundance (log2 intensity) in human scWAT pre/post exercise training. (F and G) Boxplot of FTL and FTH1 protein abundance (arbitrary unit) obtained from Western blot analysis in human scWAT pre/post exercise training. (H) Representative immunoblots from Western blot analysis.

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  Fig. 5.. Exercise training remodels iron homeostasis. (A and B) Repeated-measures correlation of human scWAT FTL and FTH1 protein expression (log2 intensity) and GIR (mg/min/m2). (C to E) Serum measurements of iron (μM), transferrin (μM), and ferritin (μg/liter). (F) Repeated-measures correlation matrix of parameters related to iron homeostasis. (G) Graphical illustration of a proposed model of iron homeostasis in human scWAT. HIIT elevates intracellular ferritin levels, promoting iron storage and diminishing the free iron labile pool. This reduces Fe2+ oxidation in the Fenton reaction, subsequently leading to fewer radical oxygen species. Such a mechanism could protect the cell from mitochondrial damage and lipid peroxidation.