Objective To explore mechanism of gastric bypass in treating obesity with type 2 diabetes mellitus (T2DM) and its relationship with c-Jun N-terminal kinase (JNK) signaling pathway. Methods The INS-1 cells were divided into 4 groups according to the different treatment: control group (complete medium), high glucose group (30 mmol/L glucose medium), exendin-4 group (high glucose+100 nmol/L exendin-4), and JNK agonist group (high glucose+100 nmol/L exendin-4+JNK agonist). When these cells were cultured on day 7, the cell activity was assessed by the MTT staining. The cell apoptosis was determined by the fluorescence microscopy analysis after the Hoechst/PI staining and flow cytometric assay after the Annexin V-FITC/PI staining. The expressions of the human immunoglobulin binding protein (Bip), CCAAT/enhancer-binding protein homologous protein (CHOP), P-SAPK/JNK, and caspase-3 protein were detected by the Western blot. Results Compared with the control group, the cell activities were significantly decreased (P<0.05), the cell apoptosis rates and the P-SAPK/JNK and caspase-3 protein expression levels were significantly increased (P<0.01) in the high glucose group and the JNK agonist group, but the Bip and CHOP protein expression levels were significantly increased (P<0.01) in the high glucose group. Compared with the high glucose group, the cell activity was significantly increased (P<0.05), the cell apoptosis rate and the Bip, CHOP, P-SAPK/JNK, and caspase-3 protein expression levels were significantly decreased (P<0.01) in the exendin-4 group, the Bip and CHOP protein expression levels were significantly decreased (P<0.01) in the JNK agonist group. Compared with the exendin-4 group, the cell activity was significantly decreased (P<0.05), the cell apoptosis rate and the P-SAPK/JNK and caspase-3 protein expression levels were significantly increased (P<0.01) in the JNK agonist group. Conclusion Gastric bypass can inhibit endoplasmic reticulum stress of pancreatic islet β-cells by regulating secretion of glucagon like peptide-1, thereby inhibiting JNK signaling pathway, protecting pancreatic islet β-cells and inhibiting apoptosis, so as to achieve effect of treating T2DM.
ObjectiveTo investigate the regulatory mechanism of transforming growth factor-β1 (TGF-β1) in different types of mitral valvular disease (MVD) with atrial fibrillation (AF). MethodsFrom August 2011 to August 2012, 16 patients with moderate to severe MVD accompanied by AF who required mitral valve replacement at the Department of Cardiovascular Surgery, West China Hospital, Sichuan University, were included. Based on echocardiographic results, patients were divided into two groups: a mitral regurgitation (MR) with AF (MR-AF) group and a mitral stenosis (MS) with AF (MS-AF) group. Left atrial tissue samples were collected during surgery. Techniques such as enzyme-linked immunosorbent assay, real-time fluorescence quantitative polymerase chain reaction, immunohistochemistry, and Western blotting were used to detect key molecules in the TGF-β1/JNK pathway. ResultsThere were 8 patients in the MR-AF group, including 5 males and 3 females, with an average age of (41.38±11.19) years; and 8 patients in the MS-AF group, including 6 males and 2 females, with an average age of (43.12±5.30) years. The left atrial volume load was higher in MR-AF patients, while the left atrial pressure load was higher in MS-AF patients. In MS-AF patients, the relative expression levels of MAPK9, JUN, CASP3, BAX, and BCL2 mRNA in left atrial tissues were significantly upregulated. The serum TGF-β1 protein level and the relative expression levels of p-JNK, p-c-Jun, and Caspase-3 proteins in the left atrial tissues of the MR-AF group were higher. Myocardial cell damage was more severe in the MS-AF group, and the expression level of Bcl-2 was higher. ConclusionDifferent mitral valve lesions have distinct hemodynamic characteristics. The myocardium of the left atrium in MR-AF patients is more prone to apoptosis, possibly through the activation of the TGF-β1/JNK signaling pathway.
Objective To observe the level of vitamin D in patients with steroid resistant (SR) asthma, and investigate the effect of 1,25-(OH)2D3 on JNK/AP-1 and glucocorticoid receptor of T lymphocytes in SR asthmatics. Methods Sixty-two outpatients and inpatients with asthma with acute exacerbation between 2014 and 2015 were recruited in the study, including 26 cases of steroid sensitive (SS) asthmatics and 36 cases of SR asthmatics. Meanwhile 25 healthy volunteers were recruited as control. Clinical data were collected and peripheral venous blood was sampled for measuring the level of 25-(OH)D and separating the T lymphocytes. T lymphocytes were assigned to six groups, ie. a healthy control group (Group A), a SS asthmatics control group (Group B), a SR asthmatics control group (Group C), a SR asthmatics with JNK inhibitor (SP600125)+1,25-(OH)2D3 group (Group D), a SR asthmatics with JNK inhibitor (SP600125) group (Group E), and a SR asthmatics with 1,25-(OH)2D3 group (Group F). T lymphocytes were cultured for 48 hours. By the end of culture, the expression of phospho-JNK (p-JNK) and phospho-glucocorticoid receptor (p-GR) of T lymphocytes were detected by Western blot method, and the expression of c-Jun mRNA was detected by RT-PCR method. Results The level of 25-(OH) D was lower in Group B and Group C than Group A (P<0.05), and lower in Group C than Group B (P<0.05). The level of p-JNK was higher in Group B and Group C than Group A (P<0.05), higher in Group C than Group B (P<0.05), lower in Group E and Group F than Group C (P<0.05), lower in Group D than Group F (P<0.05). The level of p-GR was lower in Group C than Group A and Group B (P<0.05), higher in Group E and Group F than Group C (P<0.05), higher in Group D than Group F (P<0.05). The level of c-Jun mRNA was higher in Group B and Group C than Group A (P<0.05), higher in Group C than Group B (P<0.05), lower in Group E and Group F than Group C (P<0.05), and lower in Group D than Group F (P<0.05). The 25-(OH) D level was negatively correlated with the expression of p-JNK and c-Jun mRNA in Group C (r=–0.69, r=–0.65, P<0.05). However, there was a positive correlation between the 25-(OH) D level and p-GR (r=0.72, P<0.05). Conclusions There is a high prevalence of vitamin D deficiency or lack in SR asthmatics. 1,25-(OH)2D3 can promote the expression of p-GR by inhibiting the JNK/AP-1 signaling pathway of T lymphocytes in SR asthmatics, which may be one of the mechanisms of vitamin D to improve glucocorticoid resistance in SR asthmatics.