Objective To study the effects of adenosine 2A receptor activation on activation, proliferation, and toxicity of T lymphocytes stimulated by phytohemagglutinin (PHA) in vitro. Methods A model of activated T cells was established by stimulating the cells with PHA. Those T cells were treated with different concentrations of adenosine 2A receptors agonist (0.01 μmol/L, 0.1 μmol/L, 1 μmol/L, and 10 μmol/L CGS21680). The expressions of CD69, CD25 and proliferation of T cells were measured by fluorescent antibody stain and flow cytometry. ELISA method was used to detect IL-2 and INF-γ levels. Results All concentrations of CGS21680 significantly inhibited the expressions of CD25 and CD69 on PHA-stimulated T cells surface and proliferation of T cells （Plt;0.05， Plt;0.01）. IL-2 and INF-γ secreted by T cells were significantly suppressed, too （Plt;0.01）. Conclusion Activation of adenosine 2A receptor can effectively inhibit the activation, proliferation, and toxicity of T cells in vitro.
Objective To review research progress of pancreas stellate cells in pancreas fibrosis and understand characteristics and activation of pancreas stellate cells and its mechanism on pancreas fibrosis. Method The relevant literatures about pancreas stellate cells and its studies in pancreas fibrosis were reviewed. Results The activation of pancreatic stellate cell is associated with fibrosis of pancreatitis and end stage of pancreas transplantation, but its effect and regulation mechanisms for the extracelluar and intracellular molecular network need to be further investigated. Conclusion Elucidation of activation of pancreas stellate cells will facilitate understanding of pancreas fibrosis and searching new target in treatment of pancreas fibrosis.
Calnexin is a lectin-like molecular chaperone protein on the endoplasmic reticulum, mediating unfolded protein responses, the endoplasmic reticulum Ca2+ homeostasis, and Ca2+ signals conduction. In recent years, studies have found that calnexin plays a key role in the heart diseases. This study aims to explore the role of calnexin in the activation of cardiac fibroblasts. A transverse aortic constriction (TAC) mouse model was established to observe the activation of cardiac fibroblasts in vivo, and the in vitro cardiac fibroblasts activation model was established by transforming growth factor β1 (TGFβ1) stimulation. The adenovirus was respectively used to gene overexpression and silencing calnexin in cardiac fibroblasts to elucidate the relationship between calnexin and cardiac fibroblasts activation, as well as the possible underlying mechanism. We confirmed the establishment of TAC model by echocardiography, hematoxylin-eosin, Masson, and Sirius red staining, and detecting the expression of cardiac fibrosis markers in cardiac tissues. After TGFβ1 stimulation, markers of the activation of cardiac fibroblast, and proliferation and migration of cardiac fibroblast were detected by quantitative PCR, Western blot, EdU assay, and wound healing assay respectively. The results showed that the calnexin expression was reduced in both the TAC mice model and the activated cardiac fibroblasts. The overexpression of calnexin relieved cardiac fibroblasts activation, in contrast, the silencing of calnexin promoted cardiac fibroblasts activation. Furthermore, we found that the endoplasmic reticulum stress was activated during cardiac fibroblasts activation, and endoplasmic reticulum stress was relieved after overexpression of calnexin. Conversely, after the silencing of calnexin, endoplasmic reticulum stress was further aggravated, accompanying with the activation of cardiac fibroblasts. Our data suggest that the overexpression of calnexin may prevent cardiac fibroblasts against activation by alleviating endoplasmic reticulum stress.
Long non-coding RNA (lncRNA) Dnm3os plays a critical role in peritendinous fibrosis and pulmonary fibrosis, but its role in the process of cardiac fibrosis is still unclear. Therefore, we carried out study by using the myocardial fibrotic tissues obtained by thoracic aortic constriction (TAC) in an early study of our group, and the in vitro cardiac fibroblast activation model induced by transforming growth factor-β1 (TGF-β1). Quantitative real-time polymerase chain reaction (RT-qPCR), Western blot, and collagen gel contraction test were used to identify the changes of activation phenotype and the expression of Dnm3os in cardiac fibroblasts. Small interfering RNA was used to silence Dnm3os to explore its role in the activation of cardiac fibroblasts. The results showed that the expression of Dnm3os was increased significantly in myocardial fibrotic tissues and in the activated cardiac fibroblasts. And the activation of cardiac fibroblasts could be alleviated by Dnm3os silencing. Furthermore, the TGF-β1/Smad2/3 pathway was activated during the process of cardiac fibroblasts activation, while was inhibited after silencing Dnm3os. The results suggest that Dnm3os silencing may affect the process of cardiac fibroblast activation by inhibiting TGF-β1/Smad2/3 signal pathway. Therefore, interfering with the expression of lncRNA Dnm3os may be a potential target for the treatment of cardiac fibrosis.
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.