Fig. 5: Dynamic recruitment of c-kit⁺ progenitor-derived brown adipocytes is involved in pathophysiological adipose remodeling.

A Schematic depicting the experimental procedure for the exposure of Kit-CreER; Rosa26-RFP mice to cold temperature (4 °C) or to room temperature (RT; 22 °C) for 4 weeks after Tam treatment. B Representative H&E staining of adipose tissue sections of iBAT and ingWAT depots in the cold and RT group, n = 6 mice/group. C-D Immunofluorescence (IF) staining of tissue sections of iBAT (C) and ingWAT (D) for RFP and UCP1. Quantitative analysis showing cold exposure increased the percentages of RFP⁺UCP1⁺ cells both in iBAT (C) and ingWAT (D). C, D Each dot indicates a value from one mouse and n = 6 mice/group. The data are presented as the mean ± SEM. *P < 0.05 (RT versus Cold). E Schematic illustrating Tam-induced Kit-CreER; Rosa26-RFP mice fed on a high-fat diet (HFD) or chow diet (Control) for 16 weeks. F H&E staining of adipose tissue sections of iBAT and ingWAT depots from control and HFD mice, n = 6 mice/group. G-H Representative IF images of iBAT (G) and ingWAT (H) tissue sections double-stained for RFP and UCP1. Quantitative analysis indicating that HFD significantly reduced the proportion of RFP⁺UCP1⁺ cells in iBAT (G). RFP⁺UCP1⁺ cells were scarcely observed in ingWAT (H) in both the control and HFD mice. G Each dot indicates a value from one mouse and n = 8 mice/group. The data are presented as the mean ± SEM. *P < 0.05 (Control versus HFD). H Each dot indicates a value from one mouse and n = 7 mice/group. The data are presented as the mean ± SEM. *P < 0.05 (Control versus HFD). I Graph representing adipose tissues was collected for analysis from Kit-CreER; Rosa26-RFP mice at 10 weeks, 40 weeks, 70 weeks, and 100 weeks after Tam treatment. J Quantitation of RFP⁺UCP1⁺ cells in iBAT at different ages. Each dot indicates a value from one mouse and n = 4 mice/group. The data are presented as the mean ± SEM. *P < 0.05 (Tam 40 w versus Tam 70 w; Tam 70 w versus Tam 100 w). Scale bar = 100 μm. K Representative images of iBAT tissue sections double-stained for RFP and UCP1 at indicated time points.