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 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.

A facial allotransplanted patient presented hyperglycemia with blood glucose ranged 14. 3 -33. 3 mmol/L after receiving immunosuppressive drugs and glucocorticoids. To control the blood glucose level, the patient was treated with two subcutaneous doses of 10 U human neutral protamine hagedorn (NPH) insulin, and the fasting glucose level came down to 3. 6 - 9. 4 mmol/L. Then the continuous subcutaneous infusion of insulin aspart ( Novo Industri) was administrated (from 96 to 21 U/d) , and the fasting blood glucose levels were 3. 9 -4. 6 mmol/L. With oral administration of Metformin and Repaglinide, the fasting blood glucose was maintained to 4. 3 -5.9 mmol/L. With these medications, the blood glucose level of the patient was under good control and the acute and chronic complications of hyperglycemia were effectively prevented.