Fig 2: Nur77 and NOR1 protein response to insulin before and after exercise training. (A) The Nur77 protein expression in response to insulin modestly improved from PRE to POST exercise training (PRE: -1.2 ± 0.3%, POST: +6.2 ± 1.5%, P = 0.024), whereas the NOR1 response to insulin remained unchanged (B). With aerobic exercise training, changes in the Nur77 response to insulin were associated with changes in the NOR1 response to insulin (C).

Fig 3: Liraglutide-activated ERK5 signaling pathway protein expression. MC3T3-E1 cells were treated with different concentrations of liraglutide for 48 h, and then the protein expression of MEK5, NUR77, ERK5, and p-ERK5 was measured by western blot (a, d). Quantitative analysis of the protein level of MEK5 (b), NUR77 (c), and p-ERK5 (e) in MC3T3-E1 cells after treatment with liraglutide for 48 h. aP < 0.01 compared with 0 nM, bP < 0.01 compared with 10 nM, and cP < 0.01 compared with 100 nM.

Fig 4: Nur77 deletion enhances vascular smooth muscle cells (VSMCs) proliferation and matrix metalloproteinase (MMP) expression. (A) Representative images of dual immunofluorescence staining of proliferating cell nuclear antigen (PCNA) and smooth muscle (SM)-a-actin (scale bar, 100 µm) and quantification of the ratio of PCNA-positive area to a-actin-positive area in wild-type (WT) and Nur77-deficent mice (*p<0.05, n=6). (B and C) Representative images of (B) TUNEL staining (scale bar, 100 µm) and (C) quantification of the percentage of TUNEL-positive nuclei (*p<0.05, n=6). (D and E) Representative images of (D) immunofluorescence staining of MMP-9 (scale bar, 100 µm) and (E) quantification of ratio of the MMP-9-positive area to intima area (*p<0.05, n=6). Values represent the means ± SEM.

Fig 5: FGF1?HBS attenuates mitochondrial dysfunction in primary cardiomyocytes via AMPK-Nur77 pathway. a–k Primary cardiomyocytes were transfected with control or AMPK siRNA and starved for 12 h, and then cardiomyocytes were treated with palmitate (500 µM) and high glucose (35 mM) with or without CsnB (10 µg/mL) in FBS free medium for 1 h, followed by incubation with FGF1?HBS (500 ng/mL) for additional 48 h. Mannitol + control siRNA group was an osmotic control. a Representative images of MitoTracker staining (left panel) and mitochondrial length (right panel) of primary cardiomyocytes. b–d Representative images of MitoSox (b), DHE (c), and 10-N-nonyl acridine orange (NAO) (d) staining and corresponding quantitative analysis of fluorescence intensity. e Representative images of TMRE staining (left panel) and quantitative analysis (right panel) of fluorescence intensity. f Mitochondrial membrane potential was evaluated by the ratio of JC-10 fluorescence intensities at 529 nm (green) and 590 nm (red). g–j Mitochondrial respiratory function was assessed by OCR assay. k Western blot analysis (left panel) and densitometric quantification (right panel) of AMPKa2, SIRT1, Nur77, Drp1, Nrf2 and SOD2 in the cardiomyocytes. n = 3 independent experiments for each group. Data were mean ± SEM; *P < 0.05, **P < 0.01, ***P < 0.001