Effects of Andrographolide on the Activation of Mitogen Activated Protein Kinases and Nuclear Factor-κ B in Mouse Peritoneal Macrophage-derived Foam Cells

Objective： To observe the effect of andrographolide on the activation of mitogen-activated protein kinases （MAPKs） and expression of nuclear factor- kB （NF-kB） in macrophage foam cells. Methods： The mouse peritoneal macrophages were cultured in the media in the presence of oxidized low-density lipoprotein （ox-LDL）, ox-LDL＋andrographolide, or neither （control）. The phosphorylation of MAPK molecules （p38MAPK, JNK, ERK1/2） and the expressions of NK- kB p65 were examined by Western blot. Results： As compared with cells in the control group, the expressions of phospho-p38 and NF- kB p65 were increased in the cells cultured with either ox-LDL or ox-LDL＋andrographolide （P〈0.01）, but attenuated significantly in the presence of ox-LDL＋ andrographolide when compared with ox-LDL （P〈0.05）. The phospho-JNK increased in the presence of either ox-LDL or ox-LDL＋andrographolide when compared with control cells （P〈0.01）, but no significant difference existed between ox-LDL and ox-LDL＋andrographolide （P〉0.05）. The expression of phospho-ERK1/2 was increased in the presence of ox-LDL compared with the control cells （P〈0.01）, but no significant differences existed between the cells cultured in the presence of ox-LDL＋andrographolide and the control medium （P〉0.05）. Conclusions： Andrographolide could inhibit the activation of ERK1/2, p38MAPK and NK-kB induced by ox-LDL in macrophage foam cells, which might be one of its mechanisms in preventing atherosclerosis.

Differential expression of miRNA in THP-1-derived foam cell model induced by drug-containing serum of Yimaijiangzhi decoction

Objective: To investigate the differential expression of miRNA and related biological functions and signaling pathways after the intervention of the THP-1-derived foam cell model with the drug-containing serum of Yimaijiangzhi Decoction. Methods: The experiment was divided into macrophage group, foam cell model group and Yimaijiangzhi drug-containing serum group. THP-1 cells were induced into macrophages by Fopol ester, and induced differentiated macrophages were given ox-LDL to establish foam cell model, and Yimaijiangzhi decoction rat serum was used to intervene the foam cells. Total RNA was extracted from cells in each group for miRNA sequencing, differential expression of miRNA was screened, and relevant target genes were predicted for GO analysis and KEGG analysis, protein interaction network and miRNA-target gene interaction network were established, and RT-qPCR was used to verify the possible signaling pathways for improving atherosclerosis. Result: The difference miRNA between blank group and model group was hsa-miR-302c-3p, hsa-miR-302d-3p, hsa- mir-30d-3p, hsa-mir-3189-3p, hsa-mir-374b-5p, hsa-mir-423-5p, hsa-mir-423-5p, and hsa- mir-4781-3p, hsa-mir-663a;The miRNAs of model group and Yimaijiangzhi drug-containing serum group were hsa-mir-3150a-3p, hsa-mir-7704, hsa-mir-887-3p, hsa-mir-150-5p, hsa- mir-423-5p, hsa-mir-374c-3p, hsa-mir-374c-3p, hsa-mir-374b-5p;The difference of miRNAs prediction target genes between model group and Yimaijiangzhi drug-containing serum group showed that the miRNA prediction target genes were mainly enriched in MAPK signaling pathway, ErbB signaling pathway, Hippo signaling pathway, Wnt signaling pathway and other signaling pathways. SCN1A, PRKACA, MECP2, EIF4E, SRSF1, MBNL1, PRKCA, PPARGC1A may be the potential key targets for the effect of the drug-containing serum of Yimaijiangzhi Decoction on THP-1-derived foam cells. Conclusion: hsa-mir-374c-3p, hsa- mir-423-5p, and hsa-mir-374b-5p are important miRNAs that the drug-containing serum of Yimaijiangzhi Decoction acts on foam cells. The significantly differentially expressed mirnas and significantly enriched related signaling pathways may provide new ideas for the diagnosis and treatment of atherosclerosis.

Lipid homeostasis and the formation of macrophage-derived foam cells in atherosclerosis

Atherosclerosis is a chronic,inflammatory disorder characterized by the deposition of excess lipids in the arterial intima.The formation of macrophage-derived foam cells in a plaque is a hallmark of the development of atherosclerosis.Lipid homeostasis,especially cho-lesterol homeostasis,plays a crucial role during the formation of foam cells.Recently,lipid droplet-associated proteins,including PAT and CIDE family proteins,have been shown to control the development of athero-sclerosis by regulating the formation,growth,stabiliza-tion and functions of lipid droplets in macrophage-derived foam cells.This review focuses on the potential mechanisms of formation of macrophage-derived foam cells in atherosclerosis with particular emphasis on the role of lipid homeostasis and lipid droplet-associated proteins.Understanding the process of foam cell for-mation will aid in the future discovery of novel thera-peutic interventions for atherosclerosis.

MicroRNA sequences modulating inflammation and lipid accumulation in macrophage “foam” cells: Implications for atherosclerosis

Accumulation of macrophage"foam"cells,laden with cholesterol and cholesteryl ester,within the intima of large arteries,is a hallmark of early"fatty streak"lesions which can progress to complex,multicellular atheromatous plaques,involving lipoproteins from the bloodstream and cells of the innate and adaptive immune response.Sterol accumulation triggers induction of genes encoding proteins mediating the atheroprotective cholesterol efflux pathway.Within the arterial intima,however,this mechanism is overwhelmed,leading to distinct changes in macrophage phenotype and inflammatory status.Over the last decade marked gains have been made in understanding of the epigenetic landscape which influence macrophage function,and in particular the importance of small non-coding micro-RNA(miRNA)sequences in this context.This review identifies some of the miRNA sequences which play a key role in regulating"foam"cell formation and atherogenesis,highlighting sequences involved in cholesterol accumulation,those influencing inflammation in sterol-loaded cells,and novel sequences and pathways which may offer new strategies to influence macrophage function within atherosclerotic lesions.

Thymic Stromal Lmphopoietin Pomotes Macrophage-derived Foam Cell Formation

The effect of thymic stromal lymphopoietin（TSLP） on macrophage-derived foam cell formation and the underlying mechanism were studied. Macrophages isolated from C57BL/6 mice were co-cultured in vitro with different concentrations of TSLP or TSLPR-antibody in the presence of oxidized low density lipoprotein（ox-LDL）. The effects of TSLP on macrophage-derived foam cell formation were observed by using oil red O staining and intracellular lipid determination. The expression levels of foam cell scavenger receptors（CD36 and SRA） as well as ABCA1 and TSLPR were detected by using RT-PCR and Western blotting. As compared with the control group, TSLP treatment significantly promoted lipid accumulation in macrophages, significantly increased protein expression of CD36 and TSLPR in a dose-dependent manner, and significantly reduced the expression of ABCA1 protein in a dose-dependent manner. No significant differences were noted between the TSLPR-antibody group and the control group. TSLP may down-regulate the expression of cholesterol efflux receptor ABCA1 and up-regulate scavenger receptor expression via the TSLPR signaling pathway, thereby promoting macrophage-derived foam cell formation.

Berberine promotes the development of atherosclerosis and foam cell formation by inducing scavenger receptor A expression in macrophage

Berberine is identified to lower the serum cholesterol level in human and hamster through the induction of low density lipoproteins （LDL） receptor in hepatic cells. To evaluate its potential in preventing atherosclerosis, the effect of berberine on atherosclerosis development in apolipoprotcin E-deficient （apoE^-/-） mice was investigated. In apoE^-/- mice, berberine induced in rivo foam cell formation and promoted atheroselerosis development. The foam cell formation induced by berberinc was also observed in mouse RAW264.7 cells, as well as in mouse and human primary macrophages. By inducing scavenger receptor A （SR-A） expression in macrophages, berberine increased the uptake of modified LDL （DiO-Ac-LDL）. Bcrberine-induced SR-A expression was also observed in macrophage foam cells in vivo and in the cells at atherosclerotic lesion. Analysis in RAW264.7 cells indicated that berberine induced SR-A expression by suppressing PTEN expression, which led to sustained Akt activation. Our results suggest that to evaluate the potential of a cholesterol-reducing compound in alleviating atherosclerosis, its effect on the ceils involved in atherosclerosis development, such as macrophages, should also be considered. Promotion of foam cell formation could counter-balance the beneficial effect of lowering serum cholesterol.

Liraglutide reduces oxidized LDL-induced oxidative stress and fatty degen- eration in Raw 264.7 cells involving the AMPK/SREBP1 pathway

Baekgound Recent studies have suggested a potential role for liraglutide in the prevention and stabilization ofatherosclerotic vascular disease. However, the molecular mechanisms underlying the effect of liraglutide on atherosclerosis have not been well elucidated. The pur- pose of this study was to examine whether liraglutide protects against oxidative stress and fatty degeneration via modulation of AMP-activated protein kinase （AMPK）/sterol regulatory element binding transcription factor 1 （SREBP1） signaling pathway in foam ceils. Methods Mouse macrophages Raw264.7 cells were exposed to oxidized low density lipoprotein （oxLDL） to induce the formation of foam cells. The cells were incubated with oxLDL （50 μg/mL）, liraglutide （0.1, 0.5, 1 and 2 nmol/L） or exendin-3 （9-39） （1, 10 and 100 nmol/L） alone, or in combination. Oil Red O staining was used to detect intracellular lipid droplets. The levels of TG and cholesterol were measured using the commercial kits. Oxidative stress was determined by measuring intracellular reactive oxygen species （ROS）, malondialdehyde （MDA） and superoxide dismutase 1 （SOD）. Western blot analysis was used to examine the expression of AMPKal, SREBP1, phosphory- lated AMPKal, phosphorylated SREBP1, glucagon-like peptide-1 （GLP-1） and GLP-1 receptor （GLP-1R）. Results Oil Red O staining showed that the cytoplasmic lipid droplet accumulation was visibly decreased in foam cells by treatment with liraglutide. The TG and cholesterol content in the liraglutide-treated foam cells was significantly decreased. In addition, foam ceils manifested an impaired oxidative stress following liraglutide treatment, as evidenced by increased SOD, and decreased ROS and MDA. However, these effects of liraglutide on foam cells were attenuated by the use of GLP-IR antagonist exendin-3 （9-39）. Furthermore, we found that the expression level of AMPKa 1 and phosphorylated AMPKct 1 was significantly increased while the expression level of SREBP 1 and phosphorylated SREBP 1 was significantly decreased in foam cells following treatment with liraglutide. Conclusions This study for the first time demonstrated that the effect of liraglutide on reducing oxidative stress and fatty degeneration in oxLDL-induced Raw264.7 cells is accompanied by the alteration of AMPK/SREBP1 pathway. This study provided a potential molecular mechanism for the effect of liraglutide on reducing oxidative stress and fatty degeneration.

Role of VLDL Receptor in the Process of Foam Cell Formation

The role of very low density lipoprotein receptor (LVLDR) in the process of foam cell formation was investigated. After the primary cultured mouse peritoneal macrophages were incubated with VLDL, β VLDL or low density lipoprotein (LDL), respectively for 24 h and 48 h, foam cells formation was identified by oil red O staining and cellular contents of triglyceride (TG) and total cholesterol (TC) were determined. The mRNA levels of LDLR, LDLR related protein (LRP) and VLDLR were detected by semi quantitative RT PCR. The results demonstrated that VLDL, β VLDL and LDL could increase the contents of TG and TC in macrophages. Cells treated with VLDL or β VLDL showed markedly increased expression of VLDLR and decreased expression of LDLR, whereas LRP was up regulated slightly. For identifying the effect of VLDL receptor on cellular lipid accumulation, ldl A7 VR cells, which expresses VLDLR and trace amount of LRP without functional LDLR, was used to incubate with lipoproteins for further examination. The results elucidated that the uptake of triglyceride rich lipoprotein mediated by VLDLR plays an important role in accumulation of lipid and the formation of foam cells.

The Effect of Neferine on Foam Cell Formation by Anti-low Density Liporotein Oxidation

Oxidatively modified low density lipoprtein (LDL) plays an important role in atheroslerosis (AS) development. To investigate the role of neferine (Nef) in anti-LDL oxidation and foam cell formation, the lipoprotein was derived and subjected to three different treatments: N-LDL (normal LDL), Cu(2+) +LDL and Cu(2+)+Nef+LDL. The LDLs were put at 25℃ for 24 h and the thiobarbituric acid reactive substance (TBARS) values were determined. They were 0. 57 ±0. 02, 6.01±0. 22 and 2. 26±0. 13 nmol/mg protein, respectively. The difference was very significant (P<0.01) for each two groups by t test. Mouse peritoneal macrophage (MΦ) were exposed to 50 μg protein/ml of Cu(2+) + LDL and Cu(2+)+Nef+LDL at 37℃ for 60 h. The tryglyceride (TG) and total cholesterol (TC) content in Mad were assayed. The results showed that Cu(2+) + LDL was more efficient than Cu(2+)+Nef+LDL in stimulating lipid accumulation in MΦ(P <0. 001). The study demonstrated that Nef could inhibit Cu(2+)-mediated LDL oxidation and thereby inhibiting macrophage-derived foam cell formation.

Microstructure and Properties of Cement Foams Prepared by Magnesium Oxychloride Cement

Microstructural features including pore size distribution, cell walls and phase compositions of magnesium oxychloride cement foams（MOCF） with various MgO powders and water mixture ratios were studied. Their infl uences on compressive strength, water absorption and resistance of MOCF were also discussed in detail. The experimental results indicated that moderate and slight excess MgO powders（MgO/MgCl2 molar ratios from 5.1 to 7） were beneficial to the formation of excellent microstructure of MOCF, but increasing water contents（H2O/MgO mass ratios from 0.9 to 1.29） might result in opposite conclusions. The microstructure of MOCF produced with moderate and slight excess MgO powders could enhance the compressive strength, while serious excess MgO powders addition（MgO/MgCl2 molar ratios = 9） would destroy the cell wall structures, and therefore decrease the strength of the system. Although MOCF produced with excess MgO powders could decrease the water absorption, its softening coefficient was lower than that of the material produced with moderate MgO powders. This might be due to the instability of phase 5, the volume expansion and cracking of cell walls as immersed the sample into water.

Heat Transfer and Acoustic Properties of Open Cell Aluminum Foams

The aluminum open cell foams have been prepared by the conventional precision casting method to investigate the thermal and acoustic properties.A water heating system and silencers were organized as a first step for its applications.The temperature increase between the top and bottom of the foam became larger as the cell size increased in the heat transfer measurement.Sound absorption ratio of the close cell foams was 60%-100%, whereas the open cell aluminum foam showed only 10%-20% of sound absorption at low frequency.When the prototype electric water heater manufactured by combining aluminum open cell foam with a heater was heated to 100-400℃,the highest temperature of water was in the range of 16-46~C.This suggests that there could be potential for this type of heater to be used as a commercial electric water heater.Sound silencer made with the aluminum open cell foam was applied to exit of exhaustion side at air pressure line.Sound silencing effect of open-celled aluminum foam showed that the noise level went down by introducing smaller cell size foam.

Influence of glucagon-like peptide 1 on the expression of ACAT1,CD36 gene and cholesterol metabolism in macrophages

Objective:To investigate whether glucagon like peptide-1(GLP-1)can reduce the cholesterol in foam cells derived from macrophages by affecting the expression of CD36 and acyl-CoA1(ACAT1)The content.Methods:Macrophages were obtained from mice,and after corresponding treatment,they were divided into 4 groups:blank control group,experimental group,GLP-1 agitation group,GLP-1 inhibition group,and the expression of CD36,ACAT1 mRNA and protein in cells of each group was detected.Expression and levels of total cholesterol(TC),free cholesterol(FC)and cholesterol ester(CE).Results:Compared with the blank control group,the content of TC,FC,CE and the expression of CD36,ACAT1 mRNA and protein in the experimental group were significantly increased(P<0.05);compared with the experimental group,the content and content of TC,FC,CE in the GLP-1 excited group The expressions of CD36 and ACAT1 mRNA and protein were significantly decreased(P<0.05);compared with the GLP-1 agitation group,the contents of TC,FC and CE and the expression of CD36,ACAT1 mRNA and protein were significantly increased in the GLP-1 inhibition group(P<0.05).Conclusion:The expression levels of CD36 and ACAT1 can be suppressed by GLP-1,and under the indirect influence of GPL-1,the level of intracellular cholesterol will also be reduced,so that the process of macrophages to foam cells is suppressed Thereby slowing down the development of atherosclerosis.

Elaborate evaluation of serum and tissue oxidized LDL level with darapladib therapy:A feasible diagnostic marker for early atherogenesis

Objective: To compare oxidized low density lipoprotein(ox LDL) levels in serum and vascular wall of Sprague-Dawley rats, identify their patterns in 8 weeks and 16 weeks of dyslipidemia induced by high fat diet, compare foam cells in aorta of each group and investigate lipoprotein-associated phospholipase A_2(Lp-PLA_2) role in atherosclerosis by darapladib administration.Methods: This study generated in twenty-four Sprague-Dawley rats. Rats were divided into 6 groups, which were received normal diet(normal group), high fat diet and high fat diet plus darapladib therapy for both 8 weeks and 16 weeks. Surgeries were performed at Week 8 and Week 16 to take the blood serum and aortic tissue. Level of ox LDL in serum,ox LDL aortic tissue, foam cell amount in aortic tissue, and Lp-PLA_2 expression in aortic tissue were measured.Results: There were significant differences in ox LDL level in serum, aortic tissue and foam cell amount(P < 0.05). There was no significant difference in Lp-PLA_2 expression in aortic tissue. Ox LDL in serum and aortic tissue had a very strong correlation(r2> 0.9, P < 0.05).This study also composed an equation for ox LDL level in aortic tissue prediction. Factorial ANOVA found that there was a significant difference of ox LDL level in the interactions between duration and location, location and treatment, and also duration, location and treatment(P < 0.01). Administration of darapladib was able to reduce levels of ox LDL in serum,aortic tissue and foam cell significantly(P < 0.05, P < 0.05 and P < 0.01, subsequently).Conclusions: Ox LDL level is location-dependent and duration-dependent. As a feasible early diagnosis, we can predict ox LDL level in aortic tissue by its level in serum. Though Lp-PLA_2 expression was unsignificant, Lp-PLA_2 inhibition by darapladib can reduce oxidative stress and inflammation in atherogenesis.

Effect of IL-10 on formation of foam cell induced by ox-LDL

Atherosclerosis is a chronic disease that causes various cardiovascular complications.It has been realized that cellular and humoral immunity plays crucial roles in atherogenic lesion formation.In this study the effects of lipopolysaccharide(LPS)and interleukin-10(IL-10)on the formation of foam cells during the early stages of ath-erosclerosis have been investigated.Macrophage was induced by phorbol myristate acetate(PMA)treatment on THP-1 cells.The cells were further stimulated by ox-LDL,ox-LDL plus LPS,ox-LDL plus IL-10 and LPS.By using an oil red O staining technique,the formation of foam cells was evaluated by lipid granules formation in the cells.The ratio of foam cell formation was increased from(9.77±1.70)%to(16.27±2.27)%after 24 h stimulation with ox-LDL,and the increase was observed with incub-ating time.The foam cells were significantly increased in the presence of LPS in a dose-dependent manner.The max-imum increase of about 40%was observed.However,the significant elevation by LPS was abrogated when IL-10 was added.These results indicated that IL-10 can effectively prevent the formation of foam cells induced by ox-LDL with or without LPS.This study demonstrates that ox-LDL can cause foam cell formation from macrophages in vitro.LPS can significantly accelerate this event.IL-10,an anti-inflammatory cytokine,can inhibit the effect of ox-LDL and LPS.These results indicate that inflammatory effects in blood vessels can speed up foam cell formation.The inhibitive effect of IL-10 is an important factor for delaying atherosclerosis processes.

Effect of atorvastatin on uptake of ox-LDL and expression of CD36 antigen during the transformation from U937cell into foam cell

Background The expression degree of CD36 in monocytes-macrophages is one of the important factors affecting lipid accumulation and foam cell transformation. Atorvastatin has anti-atherosclerosis as well as lowering blood lipid. Thus, we investigate the effect of atorvastatin on expression of CD36 and uptake of oxidized low-density lipoprotein（ox-LDL） during the formation of macrophage-derived foam cells human U937 cell line. Methods U937 cells were incubated with ox-LDL 80 mg / L to induce their transformation into foam cells. The medium was pretreated with atorvastatin 10 nmol / L. The contents of total cholesterol（TC） and cholesterol ester（CE） in cells were measured by the enzymatic fluorometric method. CD36 protein and mRNA expression levels were measured by flow cytometry and reverse transcription PCR. Results After incubated with ox-LDL, the contents of TC and CE in U937 cells increased from 302 mg / g cell protein and87 mg / g cell protein to 469 mg / g cell protein and 226 mg / g cell protein respectively. CD36 protein and mRNA expression appeared. Incubated together with atorvastatin and ox-LDL, the contents of TC and CE decreased from 469 mg / g cell protein and 226 mg / g cell protein to 378 mg / g cell protein and 119 mg / g cell protein, the levels of CD36 protein and mRNA also decreased respectively from 25.8% and 1.27 to 17.2% and0.95 compared with being incubated only with ox-LDL. Conclusion Atorvastatin could inhibit the expression of CD36 protein and mRNA in U937 cells and decrease lipid deposition, which is the important mechanism of anti-atherosclerosis as well as lowering blood lipid.

Histopathological Features Predicting Long-term Clinical Outcomes in Patients with Vanishing Bile Duct Syndrome

Background and Aims:The clinicopathological features and long-term outcomes of patients with vanishing bile duct syndrome(VBDS)have yet to be elucidated.The study aims to investigate these features and identify factors associated with poor prognosis.Methods:This multicenter retrospective study recruited patients with liver biopsy-proven VBDS who were followed up at five hospitals in northern China from January 2003 to April 2022.Clinical and pathological data at time of biopsy were reviewed.Clinical outcomes including cirrhosis,decompensation events,liver transplantation(LT),and liver-related death were recorded.Cox regression analysis was used to identify the risk factors associated with poor outcomes.Results:A total of 183 patients were included.The median age was 47 years,with 77.6%being women.During a median follow-up of 4.8 years,88 patients developed compensated or decompensated cirrhosis,27 died,and 15 received LT.Multivariate Cox regression analysis showed that hepatocellular cholestasis(HR 2.953,95%CI:1.437–6.069),foam cells(HR 2.349,95%CI:1.092–5.053),and advanced fibrosis(HR 2.524,95%CI:1.313–4.851)were independent predictors of LT or liver-related deaths.A nomogram formulated with the above factors showed good consistency with a concordance index of 0.746(95%CI:0.706–0.785).Conclusions:Nearly half of VBDS patients studied progressed to end-stage liver disease and 23%of them had LT or liver-related death within two years of diagnosis.Hepatocellular cholestasis,foam cells and advanced fibrosis rather than the degree of bile duct loss or underlying etiologies were independently associated with poor prognosis in VBDS patients.