Mitofusin 2 Promotes Apoptosis of CD4⁺ T Cells by Inhibiting Autophagy in Sepsis

Figure 1

Increased Mfn2 expression, autophagy deficiency, and upregulated apoptosis in murine splenic CD4⁺ T cells after CLP. Splenic CD4⁺ T cells were isolated from mice 24 and 72 hours after CLP. (a) Representative immunoblots and densitometric values of Mfn2 are shown; β-actin served as an internal control. (b) Representative dot plots of Annexin-V staining. (c) Representative histograms of TUNEL staining. (d) Percentage of Annexin-V- or TUNEL-positive cells. (e, f) Representative histograms and total percentage of LC3-II-positive cells. (g, h) Isolated CD4⁺ T cells were cultured with or without bafilomycin A1 (0.1 μM) for 4 hours, and the whole cell lysate was used to measure the protein expression of Beclin1, p62, and LC3-II. β-Actin served as an internal control. (i) Representative images of immunofluorescence staining against LC3. DAPI and FITC were used to label nuclei and endogenous LC3, respectively. The arrows indicate LC3 puncta. (j) Quantification of the average number of LC3 puncta per cell ( wells, 3 independent experiments, and >50 cells examined per experiment). (k) Transmission electron microscopy was used to observe autophagic vacuoles. The arrows indicate autophagic vacuoles. Data from three independent experiments are presented as the mean ± SD in the bar graph. Baf A1 or B: bafilomycin A1. , significant difference versus the sham group or the sham + B group. , significant difference versus the sham group or the sham + B group. ^#, significant difference versus the CLP1D group. ^##, significant difference versus the CLP1D group. ^$$, significant difference versus the corresponding group without bafilomycin A1 treatment.

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