[New advances in the diagnosis and treatment of biliary atresia]. / 胆道闭锁的诊断及治疗新进展.

The diagnosis of biliary atresia (BA) is mainly based on clinical manifestations, screening, and related biochemistry tests. In recent years, the development of blood biomarkers and the improvement in ultrasound examination have made it possible for BA to be diagnosed at a younger age. In particular, matrix metalloproteinase-7 shows high sensitivity and specificity and has a higher diagnostic efficiency than existing biochemical parameters, thereby holding a promise for clinical application. Sound touch elastography can increase the diagnostic efficiency for BA in terms of diagnosis and prognostic evaluation. Surgery is still the only method for the treatment of BA at present, with the preferred surgical treatment regimen of Kasai portoenterostomy combined with pharmacotherapies for alleviating infection and inflammation, and the patients who fail Kasai portoenterostomy or have liver dysfunction may require liver transplantation to save their lives. Therefore, the current research on BA should focus on the biomarkers for early diagnosis, specifically targeted drugs, and drugs for preventing progressive liver fibrosis. This article reviews the current diagnosis and treatment methods for BA and discusses the potential research directions.

Efficacy of acupuncture for sciatica: study protocol for a randomized controlled pilot trial.

BACKGROUND: Acupuncture is widely used for pain diseases while evidence of its efficacy for sciatica is insufficient. We aim to explore the feasibility and efficacy of acupuncture with different acupoint selecting strategies for sciatica induced by lumbar disc herniation. METHODS: This is a multicenter, three-arm, patient-assessor-blinded randomized controlled pilot trial. Ninety patients will be assigned randomly into 3 groups including disease-affected meridians (DAM) group, non-affected meridians (NAM) group, and sham acupuncture (SA) group in a 1:1:1 ratio. The trial involves a 4-week treatment along with follow-up for 22 weeks. The primary outcome is the change of leg pain intensity measured by the visual analogue scale (VAS) from baseline to week 4 after randomization. Secondary outcomes include functional status, back pain intensity, and quality of life. Adverse events will also be recorded. DISCUSSION: The results will inspire the optimal acupuncture strategy for sciatica and help establish a better design as well as power calculation for a full-scale study. TRIAL REGISTRATION: ChiCTR2000030680 (Chinese Clinical Trial Registry, http://www.chictr.org.cn , registered on 9 March 2020).

Epidemic characteristics and drug resistance of tuberculosis in North China.

To analyze the epidemiological characteristics and drug resistance of tuberculosis (TB) patients in northern China. The epidemiological characteristics of 620 patients with tuberculosis from 2014 to 2016 were analyzed, including gender, age, occupation, education, income, place of residence and time distribution. 148 strains were identified as mycobacterium tuberculosis infection, 46 of 148 strains were identified as resistant strains, and among of which 73.91% of mono-resistance rate, 17.39% of poly-resistance rate, and 8.70% of multidrug resistant rate. Most of the patients were male, farmers, and the age of between 40 and 60, primary education background, income of 5000-10000RMB/year and newly diagnosed patients. The resistance rates of the four first line anti-tuberculosis drugs ranked as S (streptomycin)＞R (rifampicin)＞H (isoniazid)＞E (ethambutol). 12 drug resistance spectrums were found, among them, mono-resistance was mainly concentrated in S (45.65%), poly-resistance was mainly concentrated in H + S (8.70%), and multidrug resistance was mainly concentrated in H + R (4.35%). Therefore, middle-aged people, male, farmers, education for elementary or junior high school, and new patients with incomes not exceeding 10000RMB/year will be the key population for prevention and control in the future and the main drug-resistant population. This is particularly relevant for controlling infection sources, community prevention and control, and drug resistance treatment.

EGF upregulates RFPL3 and hTERT via the MEK signaling pathway in non­small cell lung cancer cells.

Activation of the epidermal growth factor receptor (EGFR) during tumor development can trigger the MEK signaling pathway. In the present study, we investigated the MEK signaling pathway in non­small cell lung cancer (NSCLC) cells with respect to the effect of epidermal growth factor (EGF) on expression of Ret finger protein like 3 (RFPL3) and human telomerase reverse transcriptase (hTERT), and the effect of RFPL3 overexpression on other MEK signaling proteins. In vitro, A549 and H1299 cells were treated with different concentrations of EGF for 24 h or 48 h. Expression of RFPL3 and hTERT at the mRNA and protein levels was determined by real­time quantitative PCR (RT­qPCR) and western blot analysis; cell viability was detected by MTT assay, and apoptosis was assayed via flow cytometry. We also pretreated A549 and H1299 cells with EGFR tyrosine kinase inhibitors, AG1478 and erlotinib, and MEK­specific inhibitor (PD98059) in the presence of EGF. We used western blot analysis to assess the expression levels of RFPL3, hTERT and related MEK­pathway proteins in A549 and H1299 cells transfected with RFPL3­overexpression plasmids. EGF significantly upregulated RFPL3 and hTERT protein levels in the NSCLC cells. RFPL3 and hTERT proteins upregulation by EGF were attenuated by pretreatment with AG1478 and erlotinib. EGF promoted proliferation and inhibited apoptosis; PD98059 decreased RFPL3 and hTERT protein expression; and RFPL3 overexpression increased the expression of hTERT and related MEK­pathway proteins. EGF upregulated RFPL3 and hTERT protein expression in NSCLC cells via the MEK pathway, promoted cell proliferation and inhibited apoptosis. RFPL3 overexpression increased expression of hTERT and related MEK signaling proteins (Ras, Raf, ERK and p­ERK), which implies that RFPL3 is a potential therapeutic target for NSCLC.

[Efficacy of Modified Acupuncture Method at Renying (ST 9) for Patients with Cervical Spondylosis of Vertebral Artery Type and Its Impact on Velocity of Cervical Blood Flow].

OBJECTIVE: To observe the clinical efficacy of modified acupuncture at Renying point (ST 9) for patients with cervical spondylosis of vertebral artery type and its influence on velocity of cervical blood flow. METHODS: Fifty-nine cases of vertebral artery type cervical spondylosis were randomly divided into control group (n=30) and treatment group (n=29). Both groups were acupunctured at ST 9, with routine acupuncture technique used in the control group and modified technique in the treatment group, respectively. All cases received two courses of treatment, each course covered consecutive 6 once-per-day treatments. Before and after treatment, transcranial Doppler (TCD) was used to measure the systolic peak blood flow velocity (Vs) of left vertebral artery (LVA), right vertebral artery (RVA) and basilar artery (BA), and the scores of "cervical vertigo symptoms and functional assessment scale" (CVSFAS) were also assessed, separately. RESULTS: CVSFAS scoring, Vs of LVA, RVA and BA after treatment showed significant improvement compared with those before treatment (P<0.01, P<0.05). The efficacy of the treatment group in the above mentioned indexes was superior to that of the control group (P<0.05). The total effective rate of the treatment group was 93.1% (27/29), superior to 70.0% (21/30) of the control group (P<0.05). CONCLUSIONS: The modified acupuncture method at ST 9 is clinically effective in the treatment of cervical spondylosis of vertebral artery type via increasing the Vs of vertebral-basilar artery, improving the local blood circulation and relieving pain.

Epidemiological analysis of pulmonary tuberculosis in Heilongjiang province China from 2008 to 2015.

BACKGROUND: This study aimed to investigate the epidemiological characteristics of pulmonary tuberculosis (TB) in Heilongjiang province from 2008 to 2015 and provide scientific basis for the development of TB control. METHODS: The TB patients were confirmed by chest radiography and sputum examination, and the TB incidence data were from the Chinese Tuberculosis Management Information System, population data were from the National Basic Information System. RESULTS: By the SPSS statistics analysis, there was a total of 280,767 cases of TB registered in Heilongjiang province from 2008 to 2015; the average annual incidence rate was 91.60/100,000, the male incidence rate was 122.81/100,000; the female incidence rate was 59.39/100,000, and TB incidence increased as the growth of age. Farmers' incidence was higher than other occupations; Shuangyashan city incidence of 122.09/100,000 was highest during 13 cities in Heilongjiang province, all above factors existed significant difference. CONCLUSIONS: As a result, TB incidence was higher among the elderly, males and farmers, so it is important to promote the scientific knowledge about the prevention and treatment of TB. In particular, it is necessary to strengthen the health education of the elder aged people and improve the self-care awareness and ability to prevent TB.

Comparison of bone regeneration in alveolar bone of dogs on mineralized collagen grafts with two composition ratios of nano-hydroxyapatite and collagen.

To study the effect of two composition ratios of nano-hydroxyapatite and collagen (NHAC) composites on repairing alveolar bone defect of dogs. Eighteen healthy adult dogs were randomly divided into three groups. Two kinds of the NHAC composites were prepared according to the constituent ratios of 3:7 and 5:5; immediately after extraction of the mandibular second premolars, each kind of the NHAC composite was implanted into extraction socket, respectively: Group I, nHA/Col = 3:7; Group II, nHA/Col = 5:5 and Group III, blank control group. The bone-repairing ability of the two grafts was separately analyzed by morphometric measurement, X-ray tomography examination and biomechanical analysis at 1st, 3rd and 6th month post-surgical, respectively. The NHAC composites were absorbed gradually after implanting into alveolar bone defect and were replaced by new bone. The ratios of new bone formation of Group I was significantly higher than that of Group II after 3 months (P < 0.05). The structure and bioactive performance can be improved when the ratio between the collagen and the hydroxyapatite was reasonable, and the repairing ability and effect in extraction sockets are obviously better.

Nicorandil inhibits oxidative stress and amyloid-ß precursor protein processing in SH-SY5Y cells overexpressing APPsw.

It has been demonstrated that ATP-sensitive potassium (KATP) channel activation has neuroprotective effects against neuronal damage induced by hypoxia, ischemia or metabolism stress. This study investigated the multiply protective effects of KATP channel opener nicorandil against neurotoxicity in SH-SY5Y cells transiently transfected with Swedish mutant APP (APPsw) and also the potential involvement of PI3K/Akt/GSK-3ß pathway. Cells were treated with nicorandil (1 mM) for 24 h with and without glibenclamide (10 µM), a KATP channel inhibitor. Then the cells were collected for Hoechst33342, biochemical assays, real-time PCR, western blot and ELISA assay. Our results showed that nicorandil reduced apoptosis and decreased oxidative stress. Moreover, nicorandil down regulated APP695 mRNA and APP695 protein expression, also reduced Aß1-42 levels in the medium. In addition, nicorandil increased the protein levels of p-Akt and p-GSK-3ß by PI3K activation. Applying a PI3K inhibitor, LY294002 blocked the protection. These findings suggest nicorandil to be a potential therapeutic agent to treat Alzheimer's disease (AD).

[Effects of syndrome-differentiation acupuncture on life quality in patients with functional dyspepsia].

OBJECTIVE: To observe effects of syndrome-differentiation acupuncture on life quality in patients with functional dyspepsia (FD) in order to evaluate its clinical efficacy. METHODS: One hundred and five cases of FD were randomly divided into a syndrome-differentiation acupuncture group, a regular acupuncture group and a non-acupoint group, 35 cases in each one. Zhongwan (CV 12), Tianshu (ST 25), Zusanli (ST 36) were selected as main acupoints in the syndrome-differentiation acupuncture group. After syndrome differentiation, Danzhong (CV 17) and Zhangmen (LR 13) were added for those with stagnation of liver qi; Pishu (BL 20) and Weishu (BL 21) were added for those with deficiency of spleen-stomach qi; Qimen (LR 14) and Taichong (LR 3) were added for liver-qi invading stomach and Yinlingquan (SP 9) and Neiting (ST 44) were added for dampness-heat blocking stomach. The selection of acupoints in the regular acupuncture group was the same as main acupoints in the syndrome-differentiation acupuncture group. The points 10 mm lateral to the main acupoints were selected in the non-acupoint group. The treatment was given once a day, six days as a treatment course and totally two courses were required. The symptom total score, health-related quality of life survey (SF-36) and Nepean dyspepsia index (NDI) were evaluated before and after the treatment as well as one month after the treatment (follow-up visit), respectively. The efficacy was also assessed. RESULTS: After the treatment, the total effective rate was 87.5% (28/32) in the syndrome-differentiation acupuncture group, which was superior to 74.2% (23/31) in the regular acupuncture group and 20.7% (6/29) in the non-acupoint group (P < 0.05, P < 0.01). Compared before the treatment, the SF-36, NDI and symptom total score after the treatment and in the follow-up visit were all obviously improved in the syndrome-differentiation acupuncture group and regular acupuncture group (all P < 0.05), which was the most obvious in the syndrome-differentiation acupuncture group [after the treatment, SF-36: 84.54 +/- 5.93 vs 81.44 +/- 6.22, 63.46 +/- 6.59; NDSI: 18.94 +/- 9.30 vs 21.23 +/- 8.39, 43.93 +/- 11.26; NDLQI: 71.42 +/- 7.23 vs 63.11 +/- 7.06, 54.87 +/- 6.00; symptom total score: 22.06 +/- 15.80 vs 32.52 +/- 16.88, 47.97 +/- 10.92]; the improvement in the regular acupuncture group was more obvious than that in the non-acupoint group (P < 0.01, P < 0.05). Compared before the treatment, only NDSI score was improved in the non-acupoint group after the treatment (P < 0.05). CONCLUSION: The syndrome-differentiation acupuncture could obviously improve patient's life quality in the treatment of FD, which is an effective therapy for FD.

Cbl-b and PI3K/Akt pathway are differently involved in oxygen-glucose deprivation preconditioning in PC12 cells.

BACKGROUND: Transient sublethal ischemia is known as ischemic preconditioning, which enables cells and tissues to survive subsequent prolonged lethal ischemic injury. Ischemic preconditioning exerts neuroprotection through phosphatidylinositol 3-kinase (PI3K)/Akt pathway. Cbl-b belongs to the Casitas B-lineage lymphoma (Cbl) family, and it can regulate the cell signal transduction.The roles of ubiquitin ligase Cbl-b and PI3K/Akt pathway and the relationship between them in oxygen-glucose deprivation preconditioning (OGDPC) in PC12 cells were investigated in the present study. METHODS: Oxygen and glucose deprivation (OGD) model in PC12 cells was used in the present study. The 3-(4, 5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, nuclear staining with Hoechst 33258, and Western blotting were applied to explore the roles of Cbl-b and PI3K/Akt pathway and the relationship between them in OGDPC in PC12 cells. RESULTS: Cell viability was significantly changed by OGD and OGDPC. OGD significantly decreased cell viability compared with the control group (P < 0.05), and preconditioning could rescue this damage was demonstrated by the increase of cell viability (P < 0.05). The expression of Cbl-b was significantly increased after OGD treatment. However, the activation of Akt and GSK3ß was greatly inhibited. Preconditioning could inhibit the increase of Cbl-b caused by OGD and increase the activation of Akt and GSK3ß. LY294002, a specific inhibitor of PI3K, could effectively inhibit the increase of Akt and GSK3ß after preconditioning treatment. It partly inhibited the decrease of Cbl-b expression after preconditioning treatment. CONCLUSION: Ubiquitin ligase Cbl-b and PI3K/Akt pathway are differently involved in OGDPC in PC12 cells.

Specific Kv1.3 blockade modulates key cholesterol-metabolism-associated molecules in human macrophages exposed to ox-LDL.

Cholesterol-metabolism-associated molecules, including scavenger receptor class A (SR-A), lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), CD36, ACAT1, ABCA1, ABCG1, and scavenger receptor class B type I, can modulate cholesterol metabolism in the transformation from macrophages to foam cells. Voltage-gated potassium channel Kv1.3 has increasingly been demonstrated to play an important role in the modulation of macrophage function. Here, we investigate the role of Kv1.3 in modulating cholesterol-metabolism-associated molecules in human acute monocytic leukemia cell-derived macrophages (THP-1 macrophages) and human monocyte-derived macrophages exposed to oxidized LDL (ox-LDL). Human Kv1.3 and Kv1.5 channels (hKv1.3 and hKv1.5) are expressed in macrophages and form a heteromultimeric channel. The hKv1.3-E314 antibody that we had generated as a specific hKv1.3 blocker inhibited outward delayed rectifier potassium currents, whereas the hKv1.5-E313 antibody that we had generated as a specific hKv1.5 blocker failed. Accordingly, the hKv1.3-E314 antibody reduced percentage of cholesterol ester and enhanced apoA-I-mediated cholesterol efflux in THP-1 macrophages and human monocyte-derived macrophages exposed to ox-LDL. The hKv1.3-E314 antibody downregulated SR-A, LOX-1, and ACAT1 expression and upregulated ABCA1 expression in THP-1 macrophages and human monocyte-derived macrophages. Our results reveal that specific Kv1.3 blockade represents a novel strategy modulating cholesterol metabolism in macrophages, which benefits the treatment of atherosclerotic lesions.

The antibody targeting the E314 peptide of human Kv1.3 pore region serves as a novel, potent and specific channel blocker.

Selective blockade of Kv1.3 channels in effector memory T (T(EM)) cells was validated to ameliorate autoimmune or autoimmune-associated diseases. We generated the antibody directed against one peptide of human Kv1.3 (hKv1.3) extracellular loop as a novel and possible Kv1.3 blocker. One peptide of hKv1.3 extracellular loop E3 containing 14 amino acids (E314) was chosen as an antigenic determinant to generate the E314 antibody. The E314 antibody specifically recognized 63.8KD protein stably expressed in hKv1.3-HEK 293 cell lines, whereas it did not recognize or cross-react to human Kv1.1(hKv1.1), Kv1.2(hKv1.2), Kv1.4(hKv1.4), Kv1.5(hKv1.5), KCa3.1(hKCa3.1), HERG, hKCNQ1/hKCNE1, Nav1.5 and Cav1.2 proteins stably expressed in HEK 293 cell lines or in human atrial or ventricular myocytes by Western blotting analysis and immunostaining detection. By the technique of whole-cell patch clamp, the E314 antibody was shown to have a directly inhibitory effect on hKv1.3 currents expressed in HEK 293 or Jurkat T cells and the inhibition showed a concentration-dependence. However, it exerted no significant difference on hKv1.1, hKv1.2, hKv1.4, hKv1.5, hKCa3.1, HERG, hKCNQ1/hKCNE1, L-type Ca(2+) or voltage-gated Na(+) currents. The present study demonstrates that the antibody targeting the E314 peptide of hKv1.3 pore region could be a novel, potent and specific hKv1.3 blocker without affecting a variety of closely related K(v)1 channels, KCa3.1 channels and functional cardiac ion channels underlying central nervous system (CNS) disorders or drug-acquired arrhythmias, which is required as a safe clinic-promising channel blocker.

Investigations of Human and Organizational Factors in hazardous vapor accidents.

This paper presents a model to assess the contribution of Human and Organizational Factor (HOF) to accidents. The proposed model is made up of two phases. The first phase is the qualitative analysis of HOF responsible for accidents, which utilizes Human Factors Analysis and Classification System (HFACS) to seek out latent HOFs. The hierarchy of HOFs identified in the first phase provides inputs for the analysis in the second phase, which is a quantitative analysis using Bayesian Network (BN). BN enhances the ability of HFACS by allowing investigators or domain experts to measure the degree of relationships among the HOFs. In order to estimate the conditional probabilities of BN, fuzzy analytical hierarchy process and decomposition method are applied in the model. Case studies show that the model is capable of seeking out critical latent human and organizational errors and carrying out quantitative analysis of accidents. Thereafter, corresponding safety prevention measures are derived.

Chlamydia pneumoniae disturbs cholesterol homeostasis in human THP-1 macrophages via JNK-PPARγ dependent signal transduction pathways.

Chlamydia pneumoniae (C. pneumoniae) induces macrophage-derived foam cell formation, a hallmark of early atherosclerosis, in the presence of low density lipoprotein (LDL). However, its mechanisms have yet to be elucidated. In this study we examined the effects of live, heat-killed and UV-inactivated C. pneumoniae on cholesterol metabolism in THP-1-derived macrophages and the role of c-Jun NH(2) terminal kinase (JNK), which may participate in the C. pneumoniae-induced disruption of intracellular cholesterol homeostasis. We investigated whether SP600125, a special JNK inhibitor, affects the expression of peroxisome proliferator-activated receptor gamma (PPARγ), and also its downstream target genes Acyl-CoA cholesterol acyltransferase-1 (ACAT1), ATP-binding cassette transporter A1 and G1 (ABCA1/G1) in human THP-1 macrophages infected with C. pneumoniae. In this paper we found that both live and inactivated C. pneumoniae infection induce intracellular cholesterol accumulation and foam cell formation. C. pneumoniae infection increased the expression of ACAT1 and decreased the expression of ABCA1/G1, all of which facilitated cholesterol accumulation and promoted macrophage-derived foam cell formation. However, these responses were attenuated by SP600125 in a dose-dependent manner. These results demonstrate for the first time that both live and inactivated C. pneumoniae infections disturb cholesterol homeostasis in human THP-1 macrophages and C. pneumoniae infection disturbs cholesterol homeostasis via JNK-PPARγ dependent signal transduction pathways.

Role of beta1-adrenoceptor in increased lipolysis in cancer cachexia.

Increased production of hormone-sensitive lipase (HSL) protein has been demonstrated to be the major cause behind enhanced lipolysis in cancer cachexia. The mechanism governing this alteration is unknown and was presently investigated. This study was conducted to detect the expression of relevant receptors in the adipocytes of cancer cachexia patients, and to elucidate their implication in the increased lipolysis. Gene expressions of beta1-adrenoceptor (ADRB1), beta2-adrenoceptor (ADRB2), beta3-adrenoceptor (ADRB3), alpha2C-adrenoceptor (ADRA2C), natriuretic peptide receptor A (NPRA), insulin receptor (INSR), and HSL were determined in adipose tissues of 34 patients by real-time PCR. Protein levels of ADRB1 and HSL were determined by western blot analysis. beta1-Adrenoceptor (ADRB1) was also detected by immunofluorescence staining. mRNA expressions of both ADRB1 and HSL were approximately 50% elevated selectively in the cachexia group, whereas mRNA levels of the other receptors were unchanged. beta1-Adrenoceptor (ADRB1) protein expression was 1.5-fold increased in cachexia as compared with the cancer controls, and 3-fold increased as compared with nonmalignant controls, and was confirmed as a membrane protein in adipocytes by immunofluorescence. Hormone-sensitive lipase (HSL) protein expression was 2-2.5-fold increased selectively in cachectic patients. There was a positive correlation between the protein expressions of ADRB1 and HSL. As much as approximately 50% of the variations in HSL protein expression could be explained by variations in ADRB1 protein expression. There was a link between ADRB1 protein level and lipolytic rate. Increased ADRB1 expression may account for some of the functional changes of HSL in patients with cancer cachexia.

Protective effect of Astragalus polysaccharides on ATP binding cassette transporter A1 in THP-1 derived foam cells exposed to tumor necrosis factor-alpha.

Astragalus polysaccharide (APS), the main extract from the traditional Chinese medicinal herb Astragalus membranaceus, has been reported to benefit the treatment of immune-inflammatory diseases and metabolic disorders. In atherosclerotic plaques, proinflammatory cytokines exert adverse effects on lipids thereby aggravating atherosclerosis. Recent evidence shows that tumor necrosis factor-alpha (TNF-alpha) can down-regulate the expression of ATP-binding cassette transporter A1 (ABCA1), which plays a vital role in reverse cholesterol transport and determines the process of atherosclerosis. In the present study, the effects of APS on ABCA1 expression, cholesterol effluent rate and total cholesterol content of THP-1 derived foam cells exposed to TNF-alpha were investigated. Compared with the foam cells exposed to TNF-alpha, ABCA1 expression was promoted in the presence of APS. Consequently the cholesterol effluent rate increased and the total cholesterol content decreased significantly. TNF-alpha could enhance the activity of nuclear factor-kappa B (NF-kappaB) in the foam cells. This effect could be attenuated by APS. These findings suggest that APS could protect ABCA1 against the lesion of TNF-alpha in THP-1 derived foam cells, which may contribute to its antiatherosclerotic properties.

[Chlamydia pneumoniae induces THP-1-derived foam cell formation by up-regulating the expression of acyl-coenzyme A: cholesterol acyltransferase 1].

OBJECTIVE: To investigate the expression changes of acyl-coenzyme A: cholesterol acyltransferase 1 (ACAT1) on Chlamydia pneumoniae (C.pn) induced foam cell formation. METHODS: Human monocytic cell line (THP-1) was induced into macrophages by 160 nmol/L phorbol myristate acetate (PMA) for 48 h, and were randomly allocated into four groups: negative control group (50 microg/ml LDL for 48 h); positive control group (50 microg/ml ox-LDL for 48 h); C.pn infection group (50 microg/ml LDL plus 1 x 10(5), 4 x 10(5), 5 x 10(5) and 1 x 10(6) IFU C.pn for 48 h or 1 x 10(6) IFU C.pn for 0, 24, 48 and 72 h); ACAT inhibitor 58-035 plus C.pn infection group (1, 5, 10 microg/ml ACAT inhibitor 58-035 pretreatment for 1 h, 50 microg/ml LDL and 1 x 10(6) IFU C.pn for 48 h). The mRNA and protein expressions of ACAT1 were determined by RT-PCR and Western blot, respectively. Lipid droplets in cytoplasm were observed by oil red O staining. The contents of intracellular cholesteryl esters were detected by enzyme-fluorescence. RESULTS: The mRNA and protein expressions of ACAT1 were significantly up-regulated in positive control cells compared those in negative control cells and further upregulated by C.pn infection in a time-dependent and concentration-dependent manner (all P < 0.05). There were significantly increases in the accumulation of lipid droplets and the ratio of cholesteryl ester to total cholesterol in positive control cells as compared with negative control cells and these were further aggravated by C.pn (at the concentrations of 5 x 10(5) and 1 x 10(6) IFU for 48 h) and C.pn infection induced increases in the accumulation of lipid droplets and the ratio of cholesteryl ester to total cholesterol could be significantly attenuated by ACAT inhibitor 58-035 (all P < 0.05). CONCLUSION: Chlamydia pneumoniae induces THP-1-derived foam cell formation by up-regulating the expression of ACAT1.

Chlamydia pneumoniae induces macrophage-derived foam cell formation via PPAR alpha and PPAR gamma-dependent pathways.

In the presence of low density lipoprotein (LDL), Chlamydia pneumoniae induces macrophage-derived foam cell formation, a typical pathological feature of early atherosclerosis. However, its mechanism has not been fully understood. Peroxisome proliferator-activated receptors (PPARs) are key regulators of macrophage lipid metabolism. This study therefore investigated the role that PPAR alpha and PPAR gamma may play a role in C. pneumoniae-induced foam cell formation. Oil Red O staining and Lipid mass quantification showed that LDL-treated THP-1 macrophages infected with high doses of C. pneumoniae (5x10(5) and 1x10(6)IFU) resulted in the large accumulation of lipid droplets and markedly increased the ratio of intracellular cholesteryl ester (CE) to total cholesterol (TC) (>50%). The results of RT-PCR and Western blot indicated that C. pneumoniae infection dose-dependently suppressed the expression of PPAR alpha and PPAR gamma at mRNA and protein levels in LDL-treated THP-1 macrophages. PPAR alpha (fenofibrate) and PPAR gamma (rosiglitazone) agonists, inhibited the accumulation of intracellular CE by C. pneumoniae in a dose-dependent manner. Furthermore, C. pneumoniae-induced foam cell formation was significantly suppressed by higher doses of fenofibrate (20 and 50microM) and rosiglitazone (10 and 20microM). These results first reveal that C. pneumoniae induces foam cell formation via PPAR alpha and PPAR gamma-dependent pathway, which may contribute to its pro-atherogenic properties.

[Ghrelin down-regulates ACAT-1 in THP-1 derived foam cells via growth hormone secretagogue receptor-dependent pathway].

OBJECTIVE: To investigate the effects of Ghrelin on the expression of acyl coenzyme A:cholesterol acyltransferases-1 (ACAT-1) in THP-1 derived foam cells. METHODS: The human monocytic leukemia cell line (THP-1) was chosen in our study. The differentiation of THP-1 cells into macrophages was induced by phorbol 12-myristate 13-acetate. Macrophages were then incubated with oxidized LDL (ox-LDL) to generate foam cells. Ghrelin and [D-Lys3]-GHRP-6, the special antagonist of growth hormone secretagogue receptor (GHS-R), were treated during foam cells formation. The ACAT-1 protein and mRNA levels were detected by Western blot and RT-PCR. The effect of variance of cholesterol content was measured by zymochemistry via-fluorospectrophotometer. RESULTS: Ghrelin reduced the content of cholesterol ester in foam cells obviously. ACAT-1 protein and mRNA levels were also decreased. The antagonist of GHS-R inhibited the effects of Ghrelin on ACAT-1 expression in dose-dependent manner. The ACAT-1 mRNA levels of the GHS-R specific antagonist groups (10(-5), 5 x 10(-5), 10(-4) mol/L) were 1.14 +/- 0.04, 1.58 +/- 0.03, 2.40 +/- 0.16, significantly higher than that of the Ghrelin group (0.89 +/- 0.05). And the protein expressions were 1.25 +/- 0.09, 1.77 +/- 0.11, 2.30 +/- 0.09, also higher than that of the Ghrelin group (0.86 +/- 0.08). CONCLUSIONS: Ghrelin might interfere atherosclerosis by down-regulating the expression of ACAT-1 via GHS-R pathway.

Interleukin-10 inhibits the down-regulation of ATP binding cassette transporter A1 by tumour necrosis factor-alpha in THP-1 macrophage-derived foam cells.

It is suggested that cholesterol efflux mediated by ATP binding cassette transporter A1 (ABCA1) plays an important role in anti-atherogenesis. However, the effects of inflammatory cytokines on ABCA1 expression and cholesterol accumulation in foam cells are little known. This study investigates the effects of tumour necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) on ABCA1 expression and cholesterol content in THP-1 macrophage-derived foam cells. ABCA1mRNA and protein levels were determined by RT-PCR and Western blot, respectively. The total cholesterol content in THP-1 macrophage-derived foam cells was detected by the zymochemistry method. Results revealed that TNF-alpha could increase cholesterol content by down-regulating ABCA1 expression in a time-dependent manner in THP-1 macrophage-derived foam cells, which may contribute to its pro-atherosclerotic effect. In addition IL-10 time-dependently decreased cholesterol accumulation by up-regulating ABCA1 expression and inhibited the down-regulation of ABCA1 by TNF-alpha in THP-1 macrophage-derived foam cells, which may be one of the mechanisms of IL-10 contributing to its anti-atherosclerotic action.