Objective To explore the molecular mechanism by which curcumin enhances the anti-tuberculosis function of macrophages through immune metabolic regulation mediated by liver X receptor α(LXRα)/ABCA1.Methods A model was established by infecting THP-1-derived macrophages with attenuated strain of Mycobacterium bovis(M.bovis).The control group,curcumin group,M.pavis group,M.pavis+LXRα agonist(T0901317)group,M.pavis+LXRα inhibitor(GSK2033)group,M.pavis+curcumin group,M.pavis+curcumin+GSK2033 group and M.pavis+curcumin+T0901317 group were set up.The protein and gene expressions of LXRα/ABCA1 were detected by Western blotting and real-time fluorescence quantitative polymerase chain reaction(RT-qPCR).The accumulation of lipid droplets was analyzed by Oil Red O staining and micro-assay.The lipid content of the supernatant was determined by a biochemical analyzer,and cell proliferation was assessed by the MTT method.Bacterial clearance capacity was evaluated by measuring intracellular bacterial load.Results Curcumin significantly upregulated the protein and gene expression of LXRα/ABCA1 in M.Bovis-infected macrophages,reduced intracellular lipid accumulation and promoted lipid efflux,while enhancing cell proliferation and reducing intracellular bacterial load(P<0.05,P<0.01).LXRα inhibitors could reverse the effect of curcumin,while agonists synergistically enhanced its effect.Correlation analysis showed that the expression of LXRα/ABCA1 in cells was negatively correlated with the intracellular bacterial load,while the lipid level was positively correlated with the intracellular bacterial load(P<0.01).Conclusion Curcumin activates the LXRα/ABCA1 pathway,coordinates the metabolic remodeling of macrophages and the enhancement of immune function,and forms a synergistic effect against tuberculosis,providing an experimental basis for the development of a novel host-directed treatment strategy for tuberculosis based on immune-metabolic regulation.

Objective To explore the molecular mechanism by which curcumin enhances the anti-tuberculosis function of macrophages through immune metabolic regulation mediated by liver X receptor α(LXRα)/ABCA1.Methods A model was established by infecting THP-1-derived macrophages with attenuated strain of Mycobacterium bovis(M.bovis).The control group,curcumin group,M.pavis group,M.pavis+LXRα agonist(T0901317)group,M.pavis+LXRα inhibitor(GSK2033)group,M.pavis+curcumin group,M.pavis+curcumin+GSK2033 group and M.pavis+curcumin+T0901317 group were set up.The protein and gene expressions of LXRα/ABCA1 were detected by Western blotting and real-time fluorescence quantitative polymerase chain reaction(RT-qPCR).The accumulation of lipid droplets was analyzed by Oil Red O staining and micro-assay.The lipid content of the supernatant was determined by a biochemical analyzer,and cell proliferation was assessed by the MTT method.Bacterial clearance capacity was evaluated by measuring intracellular bacterial load.Results Curcumin significantly upregulated the protein and gene expression of LXRα/ABCA1 in M.Bovis-infected macrophages,reduced intracellular lipid accumulation and promoted lipid efflux,while enhancing cell proliferation and reducing intracellular bacterial load(P<0.05,P<0.01).LXRα inhibitors could reverse the effect of curcumin,while agonists synergistically enhanced its effect.Correlation analysis showed that the expression of LXRα/ABCA1 in cells was negatively correlated with the intracellular bacterial load,while the lipid level was positively correlated with the intracellular bacterial load(P<0.01).Conclusion Curcumin activates the LXRα/ABCA1 pathway,coordinates the metabolic remodeling of macrophages and the enhancement of immune function,and forms a synergistic effect against tuberculosis,providing an experimental basis for the development of a novel host-directed treatment strategy for tuberculosis based on immune-metabolic regulation.

Objective:To investigate the effect of curcumin on phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway on the autophagy of Bacille Calmette-Guérin (BCG)-infected macrophages.Methods:The infection model was established by infecting THP-1-derived macrophages with BCG. Five groups were involved in this study, which were control group, BCG group, BCG+ curcumin group, BCG+ curcumin+ IGF-1(PI3K agonist) group, and BCG+ curcumin+ LY294002 (PI3K inhibitor) group. The fluorescence intensity of autophagosomes was observed under fluorescence microscope using the fluorescent dye monodansylcadaverine (MDC staining). The expression of PI3K, Akt, mTOR, phospho-PI3K (p-PI3K), phospho-Akt (p-Akt), phospho-mTOR (p-mTOR), microtubule-associated protein 1 light chain 3-Ⅱ (LC3-Ⅱ), and Beclin-1 at protein level were detected by Western blot. Colony forming unit was used to detect macrophage load. Multiple independent, normal, and homogeneous data were compared using one-way analysis of variance, and pairwise comparisons were conducted using LSD test.Results:BCG infection significantly decreased the fluorescence intensity of autophagosomes, and the expression of autophagy marker proteins LC3-Ⅱ and Beclin-1 ( P<0.05), but increased the expression of p-PI3K, p-Akt, and p-mTOR ( P<0.05). Curcumin increased the fluorescence intensity of autophagosomes and enhanced the expression of LC3-Ⅱ and Beclin-1 proteins in a concentration-dependent manner ( P<0.05). Besides, curcumin inhibited the expression of p-PI3K, p-Akt, and p-mTOR ( P<0.05). The PI3K agonist IGF-1 reversed the above effects of curcumin. Compared with the BCG+ curcumin group, the fluorescence intensity of autophagosomes and the expression of LC3-Ⅱ and Beclin-1 proteins were further increased ( P<0.05), while the expression of p-PI3K, p-Akt and p-mTOR was further decreased ( P<0.05) in the BCG+ curcumin+ LY294002 group. Compared with the BCG group, the bacterial loads in the BCG+ curcumin group and the BCG+ curcumin+ LY294002 group decreased significantly ( P<0.05), while the bacterial load in the BCG+ curcumin+ IGF-1 group increased significantly ( P<0.05). Conclusions:Curcumin can promote the autophagy of BCG-infected macrophages, which contributes to the clearance of Mycobacterium tuberculosis by macrophages. Part of the mechanism may be related to the inhibition of PI3K/Akt/mTOR pathway.

Objective:To investigate the effect of curcumin on phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway on the autophagy of Bacille Calmette-Guérin (BCG)-infected macrophages.Methods:The infection model was established by infecting THP-1-derived macrophages with BCG. Five groups were involved in this study, which were control group, BCG group, BCG+ curcumin group, BCG+ curcumin+ IGF-1(PI3K agonist) group, and BCG+ curcumin+ LY294002 (PI3K inhibitor) group. The fluorescence intensity of autophagosomes was observed under fluorescence microscope using the fluorescent dye monodansylcadaverine (MDC staining). The expression of PI3K, Akt, mTOR, phospho-PI3K (p-PI3K), phospho-Akt (p-Akt), phospho-mTOR (p-mTOR), microtubule-associated protein 1 light chain 3-Ⅱ (LC3-Ⅱ), and Beclin-1 at protein level were detected by Western blot. Colony forming unit was used to detect macrophage load. Multiple independent, normal, and homogeneous data were compared using one-way analysis of variance, and pairwise comparisons were conducted using LSD test.Results:BCG infection significantly decreased the fluorescence intensity of autophagosomes, and the expression of autophagy marker proteins LC3-Ⅱ and Beclin-1 ( P<0.05), but increased the expression of p-PI3K, p-Akt, and p-mTOR ( P<0.05). Curcumin increased the fluorescence intensity of autophagosomes and enhanced the expression of LC3-Ⅱ and Beclin-1 proteins in a concentration-dependent manner ( P<0.05). Besides, curcumin inhibited the expression of p-PI3K, p-Akt, and p-mTOR ( P<0.05). The PI3K agonist IGF-1 reversed the above effects of curcumin. Compared with the BCG+ curcumin group, the fluorescence intensity of autophagosomes and the expression of LC3-Ⅱ and Beclin-1 proteins were further increased ( P<0.05), while the expression of p-PI3K, p-Akt and p-mTOR was further decreased ( P<0.05) in the BCG+ curcumin+ LY294002 group. Compared with the BCG group, the bacterial loads in the BCG+ curcumin group and the BCG+ curcumin+ LY294002 group decreased significantly ( P<0.05), while the bacterial load in the BCG+ curcumin+ IGF-1 group increased significantly ( P<0.05). Conclusions:Curcumin can promote the autophagy of BCG-infected macrophages, which contributes to the clearance of Mycobacterium tuberculosis by macrophages. Part of the mechanism may be related to the inhibition of PI3K/Akt/mTOR pathway.

Objective:To investigate the inhibitory effect of curcumin on oxidative stress in BCG-infected macrophages based on the Nrf2 pathway.Methods:THP-1-derived macrophages were infected.The experiment was divided into control group,BCG group,BCG+curcumin group and BCG+curcumin+ML385 group.Cellular ROS fluorescence intensity were observed under a fluores-cence microscope;Glutathione(GSH)levels were measured by Colorimetry;Western blot was used to detect the protein expressions of Nrf2,HO-1 and NQO1;MTT was used to detect the proliferation rate of macrophages.Results:BCG infection significantly enhanced ROS fluorescence intensity,reduced cell GSH content(P<0.01),inhibited protein expressions of Nrf2,HO-1 and NQO1,at the same time inhibited cell proliferation(P<0.01);curcumin significantly weakened ROS fluorescence intensity,increased GSH level(P<0.05),promoted Nrf2,HO-1 and NQO1 protein expressions and cell proliferation(P<0.01);Nrf2 inhibitor ML385 reversed the effect of curcumin.Conclusion:Curcumin can alleviate BCG-induced oxidative stress in macrophages by increasing the expression of Nrf2 and inducing the transcription of downstream antioxidant molecules.

Objective:To investigate the role of peroxisome proliferator-activated receptor γ (PPARγ)/CD36 signaling pathway in macrophage lipid metabolism after Mycobacterium tuberculosis ( Mtb) infection. Methods:THP-1-derived macrophages were infected with Mtb. Four groups were included in this study, which were control group, Mtb infection group, Mtb+ rosiglitazone (ROZ, PPARγ agonist) group and Mtb+ GW9662 (PPARγ antagonist) group. Western blot and RT-PCR were used to detect the expression of PPARγ in macrophages at protein and mRNA levels, respectively. The lipids in cells were detected by oil red O staining. The concentrations of total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL-C) and high density lipoprotein (HDL-C) in the supernatant of cell culture were detected by automatic biochemical analyzer. The expression of CD36 was detected by immunohistochemistry. CCK-8 was used to detect the proliferation rate of macrophages. Results:Mtb infection significantly increased the expression of PPARγ in macrophages ( P<0.001), promoted intracellular lipid aggregation and CD36 expression and decreased the levels of TC, TG, LDL-C and HDL-C in the supernatant of cell culture ( P<0.001) and cell proliferation rate ( P<0.001). PPARγ agonist significantly enhanced the intracellular lipid accumulation and CD36 expression that were induced by Mtb infection and down-regulated the lipid level in the supernatant of cell culture and cell proliferation rate, while PPARγ antagonist reversed the above effects. Conclusions:PPARγ played a role in lipid metabolism in Mtb-infected macrophages through affecting CD36 expression.

Objective: Many studies have shown that respiratory syncytial virus persistent infection may be the main cause of chronic respiratory pathology. However, the mechanism is unclear. Cystic fibrosis transmembrane conduction regulator (CFTR) is an apical membrane chloride channel, which is very important for the regulation of epithelial fluid, chloride ion, and bicarbonate transport. CFTR dysfunction will lead to changes in bronchial secretions and impair mucus clearance, which is related to airway inflammation. In our previous study, we observed the down-regulation of CFTR in airway epithelial cells in respiratory syncytial virus (RSV) infected mouse model. In this study, we further investigated the expression and function of CFTR by constructing an airway epithelial cell model of RSV persistent infection. Methods: 16HBE14o- cells were infected with RSV at 0.01 multiplicity of infection (MOI). The expression of CFTR was detected by real-time RT-PCR, immunofluorescence, and Western blotting. The intracellular chloride concentration was measured by N-(ethoxycarbonylmethyl)-6-methoxyquinolium bromide (MQAE) and the chloride current was measured by whole-cell patch clamp recording. Results:16HBE14o-cells infected with RSV were survived to successive passages of the third generation (G3), while the expression and function of CFTR was progressively decreased upon RSV infection from the first generation (G1) to G3. Exposure of 16HBE14o-cells to RSV led to the gradual increase of TGF-β1 as well as phosphorylation of Smad2 following progressive RSV infection. Disruption of TGF-β1 signaling by SB431542 prevented Smad2 phosphorylation and rescued the expression of CFTR. Conclusion:RSV infection can lead to defective CFTR function in airway epithelial cells, which may be mediated via activation of TGF-β1 signaling pathway.

Objective: To investigate the association between fresh fruit consumption and status of glycemic control, among patients with type 2 diabetes mellitus (T2DM). Methods: Using the stratified cluster sampling method, a cross-sectional study was conducted among 19 473 diabetic patients who were under the Disease Management Program related to the National Basic Public Health Service in Changshu county, Huai’an and Qinghe districts of Huai’an city from December 2013 to January 2014, under the combination of fasting plasma glucose (FPG) and haemoglobin A1c (HbA1c) methods, the glycemic control status in T2DM patients was assessed. Multiple logistic regression method was used to explore the relationship between fresh fruit consumption and status of glycemic control among T2DM patients. Results: 62.4% of the T2DM patients reported their amount of fruits intake in the past year. Both the levels of FPG and HbA1c decreased in T2DM patients, when the frequency and amount of fresh fruit consumption were increasing. Compared with patients who did not take fresh fruits, the risk of poor glycemic control in patients with fresh fruit consumption of 1-4 times/week and ≥5 times/week decreased 20% (OR=0.80, 95%CI: 0.73-0.87) and 30% (OR=0.70, 95%CI: 0.62-0.80), respectively. Patients with fruit consumption of 50-99 g/day and ≥100 g/day had lower risk of poor glycemic control, with ORs (95%CI) as 0.71 (95%CI: 0.62-0.83) and 0.68 (95%CI: 0.59-0.78), respectively. Conclusions The association of fresh fruit intake and glycemic control was statistically significant in patients with type 2 diabetes. With the increase of frequencies and amounts of fresh fruit consumption, the levels of FPG and HbA1c showed a decreasing trend. Our findings suggested that fresh fruit intake seemed helpful for glycemic control.

Objective To evaluate the inductive effect of interferon-γ(IFN-γ) combined with tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) on programmed necrosis of the human immortalized keratinocyte cell line HaCaT,and to explore its mechanisms.Methods In vitro cultured HaCaT cells were divided into several groups:negative control group receiving no treatment,IFN-γ group treated with 50 μg/L IFN-γ,TRAIL group treated with 4 μg/L TRAIL,and cytokine combination group treated with 50 μg/L IFN-γ and 4 μg/L TRAIL or zVAD combination group pretreated with 40 μmo/L zVAD for 1 hour followed by the treatment with 50 μg/L IFN-γand 4 μg/L TRAIL.After 48-hour treatment,the morphology of HaCaT cells were observed under a light microscope,methyl-thiazolyl-tetrazolium assay was performed to evaluate the inhibitory effect of the treatment on the proliferation of HaCaT cells,and double staining flow cytometry to detect the necrosis of HaCaT cells.Meanwhile,real-time fluorescence-based quantitative PCR (qPCR) was conducted to determine the mRNA expression of receptor interaction protein kinase 3 (RIP3) and mixed lineage kinase domain-like protein (MLKL),Western blot analysis to determine the expression of RIP1,RIP3,MLKL proteins and their phosphorylated forms (pRIP1,pRIP3,pMLKL),immunofluorescent staining to observe the distribution of pRIP3 and pMLKL in HaCaT cells,and the level of reactive oxygen species (ROS) in HaCaT cells in the above groups was detected by the fluorescence probe DCFH-DA.Statistical analysis was carried out with SPSS 22 software by using one-way analysis of variance (ANOVA) for comparing indices among different groups,and least significant difference (LSD)-t test for multiple comparisons.Results After 48-hour treatment,HaCaT cells in the cytokine combination group and zVAD combination group showed necrosis-like morphologic features.Methyl-thiazolyl-tetrazoliumassay revealed significant differences in the survival rate of HaCaT cells among the IFN-γgroup,TRAIL group,cytokine combination group,zVAD combination group and negative control group (73.16％ ± 5.71％,81.46％ ± 4.68％,72.18％ ± 2.93％,69.67％ ± 3.24％ and 100％,respectively;F =24.34,P ＜ 0.001).The necrosis rate of HaCaT cells was notably higher in the cytokine combination group and zVAD combination group (9.86％ ± 1.31％,10.33％ ± 2.16％,respectively) than in the negative control group (5.26％ ± 0.91％,t =4.61,5.07,respectively,both P ＜ 0.05).qPCR revealed that the mRNA expression of RIP3 and MLKL significantly increased in the cytokine combination group and zVAD combination group compared with the negative control group (tRIP3 =0.99,1.84,tMLKL =1.51,2.17,respectively,all P ＜ 0.05).Western blot analysis suggested that the protein expression of RIP1,RIP3,MLKL,pRIP1,pRIP3 and pMLKL significantly increased in the cytokine combination group compared with the negative control group (all P ＜ 0.05),and the zVAD combination group showed significantly decreased caspase 8 expression and increased expression of the above proteins compared with the cytokine combination group.Fluorescence microscopy showed that enhanced green dot-like or clump-like fluorescent spots (representing pRIP3) could be observed in the cytoplasm,and red fluorescent spots (representing pMLKL) could be seen on the cell membrane in the cytokine combination group.The average fluorescence intensity of ROS was significantly higher in the cytokine combination group than in the negative control group (t =702.00,P ＜ 0.05).Conclusion IFN-γcombined with TRAIL can induce the programmed necrosis of HaCaT cells with increased level of ROS.

Objective To explore the association of smoking and smoking cessation with glycemic control in male patients with type 2 diabetes. Methods From December 2013 to January 2014, a total of 7763 male patients with type 2 diabetes, who received national basic public health service in Changshu county of Suzhou city, Huai'an and Qinghe districts of Huai'an city, Jiangsu province, were recruited by cluster sampling. Questionnaire survey and anthropometric measurements were conducted, and fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) levels were measured. Multiple linear regression model was used to evaluate the association of smoking and smoking cessation with glycemic control. Results The prevalence of current smoking was 45.5%in male patients with type 2 diabetes. The levels of FPG and HbA1c increased with number of cigarettes smoked per day compared with non-smokers (P<0.001). Among patients with drug treatment, the average increase of HbA1c level in current smokers with smoking duration ≥30 years and smoking index ≥40 pack-years were 0.27% (95%CI: 0.05%-0.49%) and 0.38% (95%CI: 0.23%-0.53%),respectively. FPG and HbA1c level decreased obviously with smoking cessation years among former smokers (P<0.05). Among the patients receiving no drug treatment, no dose-response relationships were observed between smoking duration, smoking cessation years and levels of FPG and HbA1c. Conclusion Cigarette smoking was negatively related with glycemic control in male type 2 diabetes patients, especially in patients with drug treatment. Smoking cessation may be beneficial for glycemic control. Smoking cessation should be encouraged for diabetes patients as early as possible.