Enhanced Mitochondrial Dynamics and Reactive Oxygen Species Levels with Reduced Antioxidant Defenses in Human Epicardial Adipose Tissue

Figures

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  Figure 1. Mitochondrial fusion and fission mechanisms are significantly enhanced in epicardial adipose. The mRNA expression levels of MFN1 (A), MFN2 (B), OPA1 (C), DRP1 (D), FIS1 (E), and PPARGC1A (F), along with PGC-1α protein levels (G,H) were analyzed. Gene expression was quantified by RT-qPCR, and protein expression by Western blot, with normalization to the housekeeping gene or protein β-actin, respectively. The number of patients included in each assay is indicated. A p ≤ 0.05 was considered statistically different, * p ≤ 0.05; *** p ≤ 0.001. EAT, epicardial adipose tissue; DRP1, dynamin-related protein 1; FIS1, fission 1 MFN1, mitofusin 1; MFN2, mitofusin 2; OPA1, optic atrophy 1; PGC-1α, peroxisome proliferator-activated receptor gamma co-activator-1 alpha for gene and protein, respectively; SAT subcutaneous adipose tissue.

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  Figure 2. Oxidative stress is elevated in epicardial adipose tissue. DHE oxidation (A,B) was assessed by microscopy, and the integrated density per field area was quantified and normalized to the number of cells within the same field area. MDA levels were measured by high-performance liquid chromatography (HPLC) (C). The number of patients included in each assay is indicated. A p ≤ 0.05 was considered statistically different, ** p ≤ 0.01; *** p ≤ 0.001. DAPI, 4′,6-diamidino-2-phenylindole; DHE, dihydroethidium; EAT, epicardial adipose tissue; MDA, malondialdehyde; SAT, subcutaneous adipose tissue.

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  Figure 3. Antioxidant defenses are compromised in epicardial adipose tissue. Oxidized glutathione (GSSG, A) and reduced glutathione (GSH, B) levels were quantified and expressed as µmol/g protein, with the GSH/GSSG ratio calculated accordingly (C). Glutathione peroxidase (GPx, D) and glutathione reductase (GRed, E) activities were determined spectrophotometrically and expressed as U/g protein. SOD1 (F) and CAT (G) mRNA expression levels were analyzed by RT-qPCR, while SOD2 (H,I) and CAT (H,J) protein levels were quantified by Western blot. Gene and protein expression levels were normalized to the housekeeping gene or protein β-actin, respectively. The number of patients included in each assay is indicated. A p ≤ 0.05 was considered statistically different, * p ≤ 0.05; *** p ≤ 0.001. CAT, catalase; EAT, epicardial adipose tissue; GPx, glutathione peroxidase; GRed, glutathione reductase; GSH, reduced glutathione; GSSG, oxidized glutathione; SAT, subcutaneous adipose tissue; SOD, superoxide dismutase.