Fig. 5

Metformin suppresses the infiltration of T and B cells and activates AMPK of T cells in rat lung allograft. a Representative double-immunofluorescence pictures of lung parenchyma. Red fluorescence both represented p-AMPKα expression, green fluorescence represented CD3 or CD20 expression, and blue fluorescence represented nuclei. The objective magnification was 20 × or 40 ×. Scar bar, 50 μm or 20 μm. Gamma: 1.4. b Boxplots representing semi-quantitative results of CD3⁺ T cells infiltration in lung grafts, including mean count of CD3⁺ T cells per 10 high-power fields (HPF) and mean percentage of CD3⁺ T cell number/total cell number per 10 HPF. The relative expression value of p-AMPKα per CD3⁺ T cells was shown in boxplots. The relative expression value of p-AMPK was represented as mean fluorescence intensity (MFI) of p-AMPKα/ MFI of DAPI ratio in each field of view. Ten HPF was measured for each rat. c The relative expression value of p-AMPKα per CD3⁺ T cells was shown in scatter plots. Representative double-immunofluorescence pictures of double-positive cells (white arrow) and single-positive cells (yellow arrows). Red fluorescence represented p-AMPKα expression, green fluorescence represented CD3 expression, and blue fluorescence represented nuclei. The objective magnification was 40 ×. Scar bar, 20 μm. d Boxplots representing semi-quantitative results of CD20⁺ B cells infiltration in lung grafts, including mean counts of CD20⁺ B cells per 10 HPF and mean percentage of CD20⁺ B cell number/total cell number per 10 HPF. The relative expression value of p-AMPKα per CD3⁺ T cells was shown in boxplots. The relative expression value of p-AMPK was represented as MFI of p-AMPKα/ MFI of DAPI ratio in each field of view. Ten HPF was measured for each rat. One-way analysis of variance (one-way ANOVA) followed by Tukey’s multiple test, *P, 0.05, **P, 0.01. (n = 6 rats / group)