To investigate the effects of leptin on expression of acyl-coenzymeA: cholesterol acyl-transferases-1 (ACAT-1) in monocyte-macrophage differentiation, human monocytic cells (THP-1) were cultured in RPMI 1640 and made to differentiate into macrophages under the incubation with phorbol myristate acetate (PMA) for 48 h. The cells were divided into 4 groups according to different intervention factors as follows: MCs cultured in RPM11640 medium with 10% FBS for 48 h served as MC group (control group), MCs cultured in medium with serum-free RPM11640 containing 5% BSA, 100 nmol/L PMA for 48 h as MP group, MCs cultured in RPMI1640 medium with 10% FBS, 10 micromol/ml leptin for 48 h as leptin-MC group, and MCs cultured in medium with serum-free RPMI1640 containing 5% BSA. 100 nmol/L PMA, and 10 micromol/ml leptin for 48 h as leptin-MP group. Immunocytochemistry, reverse transcription polymerase chain reaction (RT-PCR) and Western blot were performed, respectively, to observe the effects of leptin on expression of ACAT-1 in the monocyte-macrophage differentiation. Our results showed that expression of ACAT-1 protein and mRNA in MP-group is two times that in MC-group (P<0.05), and the expression of ACAT-1 protein and mRNA increased by up to 4 folds in leptin-MP group-as compared with that of MC group (P<0.01). Thus, our results support the idea that expression of ACAT-1 increases more in cultured human macrophages than in monocytes, and leptin can significantly promote ACAT-1 expression. It was concluded that high expression of ACAT-1 may accelerate the development of human atherogenesis, and leptin might participate in atherogenesis by increasing expression of ACAT-1.
Atherosclerosis ; enzymology ; Cell Differentiation ; Cells, Cultured ; Humans ; Leptin ; pharmacology ; Macrophages ; cytology ; enzymology ; Monocytes ; cytology ; enzymology ; Sterol O-Acyltransferase ; biosynthesis ; genetics ; Tetradecanoylphorbol Acetate

Animals ; Macrophages, Alveolar ; drug effects ; enzymology ; Male ; Muramidase ; biosynthesis ; Quartz ; toxicity ; Rats ; Rats, Sprague-Dawley

Cysteine and aspartic proteases possess high elastolytic activity and might contribute to the degradation of the abdominal aortic aneurysm (AAA) wall. The aim of this study was to analyze, in detail, the proteases (cathepsins B, D, K, L and S, and inhibitor cystatin C) found in human AAA and healthy aortic tissue samples. The vessel walls from AAA patients (n=36) and nonaneurysmal aortae (n=10) were retrieved using conventional surgical repair and autopsy methods. Serum samples from the same AAA patients and 10 healthy volunteers were also collected. Quantitative expression analyses were performed at the mRNA level using real-time reverse transcriptase-PCR (RT-PCR). Furthermore, analyses at the protein level included western blot and immunoprecipitation analyses. Cellular sources of cysteine/aspartic proteases and cystatin C were identified by immunohistochemistry (IHC). All cysteine/aspartic proteases and cystatin C were detected in the AAA and control samples. Using quantitative RT-PCR, a significant increase in expression was observed for cathepsins B (P=0.021) and L (P=0.018), compared with the controls. Cathepsin B and cystatin C were also detected in the serum of AAA patients. Using IHC, smooth muscle cells (SMCs) and macrophages were positive for all of the tested cathepsins, as well as cystatin C; in addition, the lymphocytes were mainly positive for cathepsin B, followed by cathepsins D and S. All cysteine/aspartic proteases analyzed in our study were detected in the AAA and healthy aorta. The highest expression was found in macrophages and SMCs. Consequently, cysteine/aspartic proteases might play a substantial role in AAA.
Aged ; Aorta/enzymology ; Aortic Aneurysm, Abdominal/*enzymology ; Aspartic Acid Proteases/genetics/*metabolism ; Case-Control Studies ; Cathepsins/genetics/metabolism ; Cysteine Proteases/genetics/*metabolism ; Humans ; Lymphocytes/enzymology ; Macrophages/enzymology ; Middle Aged ; Myocytes, Smooth Muscle/enzymology ; RNA, Messenger/genetics/metabolism

Neuronal nitric oxide synthase (nNOS) is constitutively expressed in neurons of the central nervous system, where it plays a physiological role in neurotransmission. In this study, we examined the functional role of nNOS in experimental autoimmune encephalomyelitis(EAE). The effects of the specific nNOS inhibitor 7-nitroindazole on normal and EAE rats were studied by immunohistochemistry and Western blot analysis. We found that nNOS is constitutively expressed in the spinal cords of normal rats, whilst in the spinal cords of EAE rats, nNOS expression slightly increased, concomitant with the infiltration of T cells and macrophages. Immunohistochemical studies showed that nNOS expression in macrophages and astrocytes increased at the peak stage of EAE and declined thereafter. Treatment with 7-nitroindazole (30 mg/kg) significantly delayed the onset of EAE paralysis, but had no effect on either the incidence or the severity of the paralysis. These findings suggest that nNOs inhibition has a limited role in the induction of rat EAE, and that constitutive nNOS in the spinal cord functions as a novel neurotransmitter, rather than a pro-inflammatory agent.
Animals ; Astrocytes/*enzymology ; Blotting, Western ; Encephalomyelitis, Autoimmune, Experimental/drug therapy/*enzymology ; Enzyme Inhibitors/therapeutic use ; Immunohistochemistry ; Indazoles/therapeutic use ; Macrophages/*enzymology ; Male ; Nitric Oxide Synthase/antagonists&inhibitors/*metabolism ; Rats ; Rats, Inbred Lew ; Spinal Cord/cytology/*enzymology

OBJECTIVETo study the effect of peroxisome proliferator activated receptor γ (PPAR-γ) agonist on the angiotensin converting enzyme 2 (ACE2) mRNA expression in monocyte-derived macrophages of essential hypertensive patients.

METHODSTotally 57 essential hypertensive patients were randomly divided into three groups: conventional treatment group (n=18), telmisartan group (n=19), and benazepril group (n=20); 20 patients with normal blood pressure were also selected as the control group. Monocyte-derived macrophages were isolated from blood samples of patients in all four groups. The expression of ACE2 mRNA in monocyte-derived macrophages was detected by RT-PCR before treatment and 4 and 12 weeks after treatment.

RESULTSFour and 12 weeks after treatment, the systolic pressure and diastolic pressure of telmisartan group and benazepril group were significantly lower than that of the conventional treatment group (all P<0.01), and the systolic pressure and diastolic pressure of telmisartan group were significantly lower than that of the benazepril group(both P<0.01) .The expression of ACE2 mRNA in monocyte-derived macrophages were significantly lower in essential hypertensive patients than that in control group (P<0.01). After having been treated for 4 weeks and 12 weeks, the expression of ACE2 mRNA in monocyte-derived macrophages of hypertensive patients in telmisartan and benazepril groups were significantly higher than that in conventional treatment group (all P<0.01), and the expression of ACE2 mRNA in telmisartan group was significantly higher than that in benazepril group (both P<0.01).

CONCLUSIONPPAR-γ agonist could increase the ACE2 mRNA expression in monocyte-derived macrophages of essential hypertensive patients.

Aged ; Benzazepines ; pharmacology ; Benzimidazoles ; pharmacology ; Benzoates ; pharmacology ; Female ; Humans ; Hypertension ; drug therapy ; enzymology ; Macrophages ; enzymology ; Male ; Middle Aged ; PPAR gamma ; agonists ; Peptidyl-Dipeptidase A ; genetics ; metabolism ; RNA, Messenger ; genetics

OBJECTIVETo investigate the apoptosis of J774A.1 cells induced by Leptospira interrogans and the effect of caspase-3, -6 activation on the apoptosis.

METHODSMouse monocyte-macrophage like cell line J774A.1 was infected by L.interrogans serogroup Icterohaemorrhagiae serovar icterohaemorrhagiae Lai strain 56601. The apoptosis or necrosis of infected cells was examined by flow cytometry using fluorescein labeling FITC-Annexin V/PI. The activity of caspase-3, -6, and their cleaved substrates PARP and Lamin A/C were measured by fluorometry and Western Blotting, respectively.

RESULTL. interrogans strain Lai was able to induce apoptosis of J774A.1 cells and the maximal apoptotic rate was(48.81+/-5.95)% when microbe: cell ratio was 100: 1. The maximal activities of caspase-3 and -6 in the infected J774A.1 cells were (1453.41+/-36.07) and (618.65+/-39.82) FU, respectively, which were 16.38- and 9.98-fold of those uninfected cells. PARP and Lamin A/C in the infected cells were detected. Caspase-3 and -6 inhibitors remarkably blocked the L. interrogans-induced apoptosis in J774A.1 cells.

CONCLUSIONL. interrogans is able to induce the apoptosis of J774A.1 cells and intracellular caspase-3 and -6 are closely associated with the apoptosis.

Animals ; Apoptosis ; Caspase 3 ; metabolism ; Caspase 6 ; metabolism ; Cell Line ; Leptospira interrogans ; pathogenicity ; Macrophages ; enzymology ; microbiology ; pathology ; Mice

AIM AND METHODSTo further explore the functions of alveolar macrophage and their modulation mechanisms, the activity of lysozyme in rat alveolar macrophage assessed by electrophoresis was determined. The effects of androsterone and estradiol on lysozyme secretion and their mechanisms were also studied.

RESULTSThe results showed that androsterone and estradiol increased activity of lysozyme significantly (P < 0.01), indomethacin abolished those effects. This suggests that the insufficiency of sex hormones secretion as the retrogression of gonads is involved in the decrease of immunological functions, and the susceptibility to infectious diseases.

CONCLUSIONSex hormones increased activity of lysozyme, and those effects related to prostaglandin.

Androsterone ; pharmacology ; Animals ; Estradiol ; pharmacology ; Female ; Indomethacin ; pharmacology ; Macrophages, Alveolar ; drug effects ; enzymology ; secretion ; Male ; Muramidase ; metabolism ; Rats ; Rats, Wistar

We investigated whether Nd2O3 treatment results in cytotoxicity and other underlying effects in rat NR8383 alveolar macrophages. Cell viability assessed by the MTT assay revealed that Nd2O3 was toxic in a dose-dependent manner, but not in a time-dependent manner. An ELISA analysis indicated that exposure to Nd2O3 caused cell damage and enhanced synthesis and release of inflammatory chemokines. A Western blot analysis showed that protein expression levels of caspase-3, nuclear factor-κB (NF-κB) and its inhibitor IκB increased significantly in response to Nd2O3 treatment. Both NF-κB and caspase-3 signaling were activated, suggesting that both pathways are involved in Nd2O3 cytotoxicity.
Animals ; Caspase 3 ; metabolism ; Cell Line ; Macrophages, Alveolar ; drug effects ; enzymology ; NF-kappa B ; metabolism ; Neodymium ; toxicity ; Oxides ; toxicity ; Rats ; Toxicity Tests

In order to study the damage mechanism of mineral dusts on the pulmonary alveolar macrophages (AM), the changes of their death ratio, malandialdthyde (MDA) content and activities of lactate dehydrogenase (LDH) and superoxide dismutase (SOD) were measured. And the technique of cell culture in vitro was used to investigate the cytotoxicity of six mineral dusts (twelve crystal habits) from twelve mineral deposits. The results showed that wollstonite and clinoptilolite had no AM cytotoxicity while other fibrous and grainy mineral dusts could damage pulmonary AM in various degrees. The cytotoxicity of fibrous mineral dusts was greater than that of the grainy ones, and the cytotoxicity of dusts was positively correlated with the active OH- content in dusts, but not necessarily so with its SiO2 content. The high pH values produced by dust was unfavorable for the cells survival and the dusts with a low bio-resistance were safe for cells. The content of variable valence elements in dusts could influence their cytotoxicity and the surface charge of dusts was not a stable factor on their toxicity. It indicates that the shape of mineral dusts is one of the factors affecting cytotoxicity, and that the cytotoxicity of mineral dusts mainly depends on their properties.
Animals ; Cell Death ; drug effects ; Cells, Cultured ; Dust ; Macrophages, Alveolar ; cytology ; drug effects ; enzymology ; Male ; Minerals ; chemistry ; toxicity ; Rabbits ; Toxicity Tests

A primitive protozoan parasite Trichomonas vaginalis selectively activates the signal transduction pathways in macrophages (RAW264.7). This study evaluated the correlation of these signaling pathways and T. vaginalis-induced cell apoptosis. In macrophages infected with T. vaginalis, apoptosis was assessed on the basis of DNA fragmentation on agarose gel electrophoresis. Infection of macrophages with T. vaginalis induced tyrosine phosphorylation of several proteins. Infected cells with T. vaginalis were shown to associate with phosphorylation of the extracellular signal-regulated (ERK) 1/2 kinase, p38, c-Jun N-terminal kinase (JNK) mitogen-activated protein (MAP) kinases on Western blot analysis. The present finding also demonstrated a link between the ERK1/2, JNK and p38 apoptotic pathways that was modulated by T. vaginalis infection.
Animals ; Apoptosis/*immunology ; Humans ; MAP Kinase Signaling System/immunology ; Macrophages/*cytology/enzymology/*parasitology ; Mitogen-Activated Protein Kinases/*metabolism ; Phosphorylation ; Trichomonas Infections/*immunology ; Trichomonas vaginalis/*immunology