Objectives:The tumor necrosis factor-alpha (TNF-α) gene may play an important role in coronary heart disease (CHD) and myocardial infarction (MI) risk. Recently, controversial results regarding the association of the G-308 A (rs1800629)polymorphism of the TNF-α gene with CHD/MI have been reported. We herein examine a possible association between the G-308 A (rs1800629)polymorphism of the TNF-α gene and CHD/MI in a sample of the Chinese Han population.Materials and Methods:We determined the genotypes of TNF-α G-308 A (rs1800629) in 535 unrelated Chinese patients with CHD, 420 patients with MI, and 1020 coronary artery disease-free controls. Additionally, a meta-analysis of all previous studies on the TNF-α G-308 A polymorphism and the risk of CHD and MI was performed.Results:AA genotypes in the G-308 A (rs1800629)polymorphism of the TNF-α gene did not occur more frequently in CHD/MI patients than in controls; odds ratios (95% confidence intervals) were 1.743 (0.325 to 1.423) for CHD and 1.731 (0.442 to 1.526) for MI, after adjusting for conventional risk factors. Further stratification for age, gender, and other cardiovascular risk factors did not alter the prior negative findings. Pooled meta-analysis of 23 studies also found no statistically significant associations between the TNF-α polymorphism and CHD/MI risk in the genetic additive, dominant, and recessive models. Subgroup analyses showed no association between the TNF-α polymorphism and CHD/MI in Asian and Caucasian populations.Conclusion:Our study showed no association between the G-308 A (rs1800629) polymorphism of the TNF-α gene (presence of A allele) and CHD/MI in the Chinese Han population. There was no evidence of a difference in risk effects of rs1800629 between Caucasians and Asians.
Brain-derived neurotrophic factor (BDNF) is a growth factor that plays vital roles in the neuron survival, growth, and neuroplasticity. Alteration to BDNF expression is associated with major depressive disorder. However, the BDNF translational machinery in depression remains unknown. Herein, we pointed that Pdcd4, a suppressor oncogene, acted as an endogenous inhibitor for the translation of BDNF, and selectively repressed the translation of BDNF splice variant IIc mRNA in an eIF4A-dependent manner. Chronic restraint stress (CRS) up-regulated Pdcd4 expression in hippocampus via decreasing mTORC1-mediated proteasomes degradation pathway, which resulted in the reduction of BDNF protein expression. Moreover, over-expression of Pdcd4 in the hippocampus triggered spontaneous depression-like behaviors under the non-stressed conditions in mice, while systemic or neuron-specific knockout of Pdcd4 reverses CRS-induced depressionlike behaviors. Importantly, administration of Pdcd4 siRNA or an interfering peptide that interrupts the Pdcd4-eIF4A complex substantially promoted BDNF expression and rescued the behavioral disorders which were caused by CRS. Overall, we have discovered a previously unrecognized role of Pdcd4 in controlling BDNF mRNA translation, and provided a new method that boosting BDNF expression through blocking the function of Pdcd4 in depression, indicating that Pdcd4 might be a new potential target for depressive disorder therapy.
IL-37, a newly found anti-inflammatory cytokine of the IL-1 family, has both extracellular and intracellular functions. Accumulating evidences indicate that it is also involved in tumor progression. However, the mechanism and its intracellular target are unclear. In this study, clinical data from 84 patients showed that loss or reduced expression of IL-37 in lung adenocarcinoma tissues was significantly associated with tumor metastasis. We further provided evidence that IL-37 inhibited effectively tumor metastasis in vitro and in vivo. Moreover, we uncovered a novel mechanism by which IL-37 suppressed tumor cell migration via its intracellular mature form (amino acids 46-218). Intracellular mature form of IL-37, but not its extracellular form, markedly inhibited migration of multiple kinds of tumor cells through inhibiting Rac1 activation. Mechanistically, intracellular mature IL-37 directly bound to the CAAX motif in the C-terminal hypervariable region of Rac1, and then inhibited Rac1 membrane translocation and subsequent downstream signaling. Our research identifies intracellular mature IL-37 as a novel endogenous inhibitor of Rac1. Given the crucial roles of Rac1 in tumor angiogenesis and metastasis, intracellular mature IL-37 might serve as a potential strategy for the control of Rac1 activity and tumor progression.
IL-37 is a new member of IL-1 family and possesses five different isoforms (named as IL-37 a–e). IL-37b has been demonstrated as a physiological suppressor of immune responses. However, the function of other isoforms remains unknown. Here, we show that IL-37d possesses anti-inflammatory roles both in vitro and in vivo. Firstly, IL-37d is expressed in peripheral blood mononuclear cells (PBMCs) and umbilical cords-derived mesenchymal stem cells (UCMSCs). Secondly, IL-37d overexpression markedly inhibits IL-1β-induced IL-6 production in A549 cells. Consistently, bone marrow-derived macrophages (BMDMs) from IL-37d transgenic mice express low levels of pro-inflammatory cytokines (such as IL-6 and TNF-α) following LPS stimulation, compared with those from wild-type mice. Furthermore, IL-37d transgenic mice produce less pro-inflammatory cytokines, and show much less degree of LPS-induced endotoxemia in vivo. Mechanistically, IL-37d interacts with Smad3 and promotes nuclear translocation of pSmad3. SIS3 (a specific Smad3 inhibitor) treatment completely blocks the inhibitory effects of IL-37d. Thus, our data indicate that IL-37d is a functional cytokine that negatively regulates pro-inflammatory cytokines expression in a Smad3-dependent manner.
Context: Sophocarpine, a tetracyclic quinolizidine alkaloid, is one of the most abundant active ingredients in Sophora alopecuroides Linn. (Kudouzi). Sophocarpine injection was found to have significant antiviral effects against coxsackievirus B3 and therapeutic effects for viral myocarditis in the clinic. Objective: This study assessed the effects of sophocapine on overload-induced cardiac fibrosis and investigated potential mechanisms. Materials and methods: Adult male Sprague-Dawley rats were subjected to a suprarenal abdominal aorta constriction (AC) or sham to induce sustained pressure overload. Six weeks later, rats were randomly assigned to receive sophocapine (10, 20, and 40 mg/kg, gavage) or vehicle treatment for an additional 6 weeks. Six weeks after treatment, cardiac dysfunction, cardiac coefficient, cardiac fibrosis, hydroxyproline concentration, and inflammation mediators were examined. Results: When compared with the model group, the left ventricular weight/body weight decreased by 25.4% and 39.0% in 20 and 40 mg/kg sophocarpine groups, respectively. The beneficial effects were associated with amelioration of left ventricular systolic pressure (LVSP) and left ventricular enddiastolic pressure (LVEDP). Moreover, pressure overload-induced cardiac fibrosis was attenuated in sophocarpine treated groups. Importantly, sophocarpine (20 and 40 mg/kg) decreased pro-inflammatory cytokine levels (IL-6, 14.6% and 18.5%; IL-1b, 23.1% and 32.6%), collagen content (27.7% and 50.1%), as well as matrix metalloproteinases-2, 9 (MMP-2, 9) expression (MMP-2, 11.8% and 18.5%; MMP-9, 16.2% and 21.1%). Sophocarpine (40 mg/kg) inhibited IkB-a phosphorylation (19.0%). Conclusion: These findings indicated that sophocarpine potentially had antifibrotic effects. The mechanism might be due to modulation of the balance between pro-inflammatory cytokine expression and collagen content level as well as MMPs expression via the NF-kB signaling pathway.
Background Interleukin-37 (IL-37) is a new negative immune regulator. It has 5 splicing forms, IL-37a–e, and most research mainly focuses on IL-37b functions in diverse diseases. Our previous research found that IL-37d inhibits lipopolysaccharide-induced inflammation in endotoxemia through a mechanism different from that of IL-37b. However, whether IL-37d plays a role in colitis and the underlying mechanisms is still obscure. Herein, we identified whether IL-37d regulates NLRP3 inflammasome activity and determined its effect on colitis. Methods NLRP3 inflammasome in macrophages from IL-37d transgenic (IL-37dtg) and control wild type (WT) mice were activated by lipopolysaccharide and adenosine 5′-triphosphate. The expression of NLRP3 inflammasome components and its downstream effector, IL-1β, were detected by real-time polymerase chain reaction, western blot, and ELISA. The models of alum-induced peritonitis and dextran sodium sulfate (DSS)-induced colitis were used to investigate the function of IL-37d on regulating the activity of NLRP3 inflammasome in vivo. Results Our results showed that the activation of NLRP3 inflammasome in macrophage and alum-induced peritonitis was inhibited by IL-37d. Strikingly, IL-37d suppressed NLRP3 expression at the priming step via inhibiting NF-κB activation by transcriptional profiling. Moreover, the recombinant protein IL-37d attenuated NLRP3 inflammasome activation and the production of IL-1β, which could be reversed by IL-1R8 knockdown. Finally, IL-37d transgenic mice resisted DSS-induced acute colitis and NLRP3 inflammasome activation. Conclusion Interleukin-37d inhibits overactivation of the NLRP3 inflammasome through regulating NLRP3 transcription in an IL-1R8 receptor-mediated signaling pathway.
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