Fig 2: IL-1ß expression and activation of ERK, p38, and JNK/MAPK after ERK, p38, or JNK/MAPK inhibitor treatment. A Activation of ERK/MAPK after PD98059 treatment. B Activation of p38/MAPK after SB202190 treatment. C Activation of JNK/MAPK after SP600125 treatment. D Cell viability after treatment with PD98059, SB202190, or SP600125. E IL-1ß expression after PD98059 treatment. F IL-1ß expression after SB202190 treatment. G IL-1ß expression after SP600125 treatment. Similar results were obtained from three independent experiments. Data were expressed as mean ± SD; *P < 0.05, **P < 0.01, and ***P < 0.001.

Fig 3: The ERK1/2 signaling pathway was responsible for the effects of CTRP3 on MSCs.a, b Western blot analysis of phospho-Akt/Akt, phospho-ERK1/2/ERK1/2, phospho-AMPK/AMPK, and phospho-JNK/JNK following CTRP3 (n = 3). c, d Effects of U0126 (an ERK1/2 inhibitor) on CTRP3-induced upregulation of MMP9, MT1/2, and SOD2. GAPDH served as a control (n = 4). e–g Effects of ERK1/2 inhibition on MSCs migration and proliferation (n = 4). Images were at original magnification, ×200. (H) CCK-8 assays were used to detect the effects of MMP9 neutralization on CTRP3-induced cell proliferation (n = 5). i, j Effects of ERK1/2 inhibition on apoptosis induced by oxidative stress via TUNEL staining (n = 4). All data are presented as means ± SEMs. *P < 0.05; **P < 0.01; ***P < 0.001

Fig 4: Akt/JNK signal pathway is impaired in the inhibition of aMSH on adipocyte inflammation and FoxOs expressionsMouse adipocytes were pretreated with aMSH and MK-2206 or SP600125, respectively. Relative protein levels of Akt, p-Aktser473, JNK, p-JNKThr183 (A), Foxo1, Foxo3a, Foxo4, IL-6 and Leptin (B) with or without MK-2206 (n=3). Representative immunoblots and densitometric quantification for Akt, p-Aktser473, JNK, p-JNKThr183 (C), Foxo1, Foxo3a, Foxo4, IL-6 and Leptin protein (D) with or without SP600125 (n=3). The level of total GAPDH was used as the loading control. Values are mean ± SD. *P < 0.05 compared with the control.

Fig 5: MAPK/JNK signaling pathway was activated by TCF21 overexpression. At 24 h post-induction of differentiation, lysates from LV-control and LV-TCF21 cells were collected. (A) A schematic overview of the constructs used for the Cignal Finder 45-Pathway Reporter Array. A. The inducible transcription factor-responsive construct expressing firefly luciferase. B. The constitutively expressing Renilla luciferase construct. C. The non-inducible firefly luciferase reporter construct. D. The constitutively expressing GFP construct. E. The constitutively expressing firefly luciferase construct. The negative control is a mixture of C. and B. (20:1). The positive control is a mixture of D., E. and B. Each reporter is a mixture of A. and B. (20:1). (B) A Luciferase activity-based array was used in order to identify those signaling pathways that were responsive to overexpression of TCF21. Graphs are plotted as mean ± SE relative to luciferase activity in LV-control cells from three independent experiments; (C) images for TCF21, JNK1, JNK2, p-JNK1, p-JNK2, and ß-actin expressions in cells by Western blotting; (D) bands intensities were quantified by Image J software. Graphs are plotted as mean ± SE from three independent experiments. ** p < 0.01.