Objective To investigate the effect on expression regulation of calmodulin-dependent kinases casades (CaMK) Ⅱ on liver function after liver transplantation in rats. Methods Allogeneic orthotopic liver transplantation model was established by using the classic two-cuff method. The lentiviral expression systems of CaMKⅡγ protein and CaMKⅡγ shRNA were constructed. The lentiviral vector expressing CaMKⅡγ shRNA and the lentiviral vector expressing CaMKⅡγ protein were perfused into the rat after liver transplantation respectively, and the corresponding blank vector and normal saline were perfused into the control group at the same time. The serum levels of ALT and AST were measured at different time points of inferior vena cava blood in rats. Results The serum ALT and AST levels were debased in the after transplantation rats whose lentiviral vector expressing CaMKⅡγ shRNA (P<0.05). The serum ALT and AST levels were raised in the after transplantation rats whose lentiviral vector expressing CaMKⅡγ protein (P<0.05). There were no significant difference of serum ALT and AST levels between the blank control group and the saline group (P>0.05). Conclusion Specific blocking of CaMK Ⅱ signaling pathway can effectively reduce the serum ALT and AST levels after liver transplantation in rats, and enhanced CaMK Ⅱ signaling pathway increases the serum ALT and AST levels after liver transplantation in rats.
Objective To investigate the role and mechanism of peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α) in the activation of aortic valve interstitial cells (AVICs) in aortic stenosis. Methods Isolating primary AVICs and stimulating their activation with transforming growth factor β1 (TGF-β1, 30 ng/mL), the expression of PGC-1α was detected. The activation of AVICs induced by TGF-β1 was observed after overexpression of PGC-1α by adenovirus or inhibition of PGC-1α function by GW9662. The possible downstream molecular mechanism of PGC-1α in AVICs activation was screened. Finally, the phenotype was further verified in primary human AVICs. Results The expression of PGC-1α decreased after the activation of AVICs induced by TGF-β1 (control group: 1.00±0.18; 24 h: 0.31±0.10; 48 h: 0.32±0.06; 72 h: 0.20±0.07; P<0.05). Specific overexpression of PGC-1α by adenovirus inhibited the activation of AVICs induced by TGF-β1 stimulation (periostin: 3.17±0.64 vs. 1.45±0.54, P<0.05; α-smooth muscle actin: 0.77±0.11 vs. 0.28±0.06, P<0.05). On the contrary, inhibition of PGC-1α function by GW9662 promoted the activation of AVICs (periostin: 2.20±0.68 vs. 7.99±2.50, P<0.05). Subsequently, it was found that PGC-1α might inhibit the activation of AVICs through downregulating the expression of calcium/calmodulin-dependent protein kinase (CAMK1δ) (0.97±0.04 vs. 0.74±0.11, P<0.05), and downregulating the expression of CAMK1δ alleviated the activation of AVICs (periostin: 1.76±0.11 vs. 0.99±0.20, P<0.05). The possible mechanism was that the activation of mammalian target of rapamycin (mTOR) signaling pathway was inhibited by reducing the accumulation of reactive oxygen species (ROS) (778.3±139.4 vs. 159.3±43.2, P<0.05). Finally, the protective effect of PGC-1α overexpression was verified in the activated phenotype of human AVICs (periostin: 2.73±0.53 vs. 1.63±0.14, P<0.05; connective tissue growth factor: 1.27±0.04 vs. 0.48±0.09, P<0.05). Conclusions The expression of PGC-1α significantly decreases during the activation of AVICs induced by TGF-β1. The overexpression of PGC-1α significantly inhibites the activation of AVICs, suggesting that PGC-1α plays a protective role in the activation of AVICs. The possible mechanism is that PGC-1α can inhibit the activation of CAMK1δ-ROS-mTOR pathway. In conclusion, interventions based on PGC-1α expression levels are new potential therapeutic targets for aortic stenosis.
ObjectiveTo summarize the role of ionized free calcium/calmodulin/calmodulin-dependent protein kinase Ⅱ (Ca2+/CaM/CaMKⅡ) signaling pathway in liver fibrosis so as to provide a theoretical basis for the treatment of liver fibrosis. MethodThe recent literature relevant research on the role of Ca2+/CaM/CaMKⅡ signaling pathway in the process of liver fibrosis both domestically and internationally was reviewed. ResultsThe Ca2+/CaM/CaMKⅡ signaling pathway played a bidirectional regulatory role in the process of liver fibrosis, potentially facilitating the activation of hepatic stellate cells and triggering hepatocyte apoptosis through synergistic transforming growth factor-β1 and platelet-derived growth factor pathways. ConclusionsAt present, there is very little research on the role of Ca2+/CaM/CaMKⅡ signaling pathway in the process of liver fibrosis, and there is still insufficient understanding. Future research should focus on the mechanism of this signaling pathway in liver fibrosis, especially its upstream genes or downstream target proteins, which will aid to develop targeted and effective treatment strategies, achieve the reversal of liver fibrosis and even liver cirrhosis, and provide more effective treatment options for patients with liver fibrosis.