Bronchoalveolar Lavage Fluid ; Humans ; Interleukin-1beta ; metabolism ; Macrophages, Alveolar ; cytology ; drug effects ; metabolism ; Silicon Dioxide ; adverse effects ; Silicosis ; metabolism

OBJECTIVETo study the effect of SiO(2) on the expression of platelet derived growth factor (PDGF) in human silicotic alveolar macrophages (AM) and human embryonic lung fibroblasts (HELF).

METHODSHuman alveolar macrophages were collected from a silicotic patient by bronchoalveolar lavage and exposed to SiO(2) for 3, 6, 12, 18, 24 and 36 h. The cultured supernatant at 24 h was incubated with human embryonic lung fibroblasts for 6, 12, 18, 24, 36 and 48 h. The immunocytochemistry and Western blot were used to detect the level of expression of PDGF in lung fibroblasts and their supernatant respectively. (3)H-proline was used to detect the synthesis and secretion of collagen in HELF.

RESULTSThe expression of the PDGF in the supernatant of alveolar macrophages exposed to SiO(2) increased significantly and reached the peak at 24 h (average optical density: 0.282 +/- 0.019 vs 0.214 +/- 0.014, P < 0.01) with ELISA. The expression of PDGF in lung fibroblasts and their supernatant increased at different time (6, 12, 18, 24, 36 and 48 h) with immunocytochemistry and Western blot respectively when incubated with the cultured supernatant of silicotic AM exposed to SiO(2). The expression of PDGF was significantly different from the control group (P < 0.05). The synthesis and secretion of collagen in FB were increased markedly when incubated with the cultured supernatant of AM stimulated by SiO(2) compared with the control group.

CONCLUSIONSiO(2) may affect the expression of PDGF and synthesis of collagen through AM mediation and participate in the formation of lung fibrosis.

Cells, Cultured ; Collagen ; metabolism ; Fibroblasts ; drug effects ; metabolism ; Humans ; Macrophages, Alveolar ; drug effects ; metabolism ; Male ; Middle Aged ; Platelet-Derived Growth Factor ; metabolism ; Silicon Dioxide ; pharmacology

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

Cells, Cultured ; Fibroblasts ; cytology ; drug effects ; metabolism ; Humans ; Lung ; cytology ; metabolism ; Macrophages, Alveolar ; metabolism ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Silicon Dioxide ; toxicity ; Silicosis ; metabolism

OBJECTIVETo investigate the effect of L-Arginine (L-Arg) on pulmonary surfactant (PS) expression and alveolar macrophage (AM) in rats with pulmonary injury induced by lipopolysaccharide (LPS).

METHODSModel of acute lung injury (ALI) was made by injection (iv) with LPS 5 mg/kg in rats. Fourty-eight male SD rats were randomly divided into 3 groups(n = 16): control, model (LPS) and L-Arg groups. L-Arg (500 mg/kg ip ,L-Arg group) or saline (control and LPS group) was administrated at 3 h or 6 h after LPS injection respectively for 3 h. The expression of surfactant protein A (SP-A) mRNA in the lung tissue was detected by ISH. The total protein (TP) in the bronchoalveolar lavage fluid (BALF) was detected. Rat AM were isolated from the bronchial alveolar lavage fluid of SD rats and harvested by selective plating technique. LPS and L-Arg were added to the culture medium. The concentration of nitric oxide (NO),the activity of lactate dehydrogenase (LDH), the contents of tumor necrosis factor alpha (TNF-alpha) and interleukin- 6 (IL-6) in the culture supernatants were respectively measured.

RESULTSCompared with the control group, the expression of SP-A mRNA was significantly decreased, the TP concentration was significantly increased in LPS group. Compared with LPS group at the same time points, treatment with L-Arg at 3 h after LPS, the expression of SP-A mRNA in lung tissue was increased markedly, whereas TP concentration was decreased significantly. In cultured rat AM, LDH activity, NO, TNF-alpha and IL-6 contents in culture medium were significantly increased in LPS group to compared with those of control group. LDH activity, TNF-alpha and IL-6 contents were decreased in L-Arg group compared with those of LPS group.

CONCLUSIONL-Arg can protect the lung against LPS-induced pulmonary injury by up-regulating the expression of PS and inhibiting inflammatory transmitters from AM.

Acute Lung Injury ; chemically induced ; drug therapy ; metabolism ; Animals ; Arginine ; pharmacology ; therapeutic use ; Lipopolysaccharides ; adverse effects ; Macrophages, Alveolar ; metabolism ; Male ; Pulmonary Surfactants ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the effect of SiO2 on the expression of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in human silicotic alveolar macrophages (AM).

METHODSHuman alveolar macrophages were collected from a silicotic patient by bronchoalveolar lavage and exposed to silicon dioxide for 3 h, 6 h, 12 h, 18 h, 24 h and 36 h. The expression of the MMP-9 in the AM were detected with zymography and immunological method and the expression of the TIMP-1 in the AM with immunological method.

RESULTSThe expressions of MMP-9 in the AM increased clearly along with the time, reached peak at 24 h when detected with zymography (average optical density: 3.061+/-0.153 vs 2.851+/-0.164, P<0.05); and reached peak at 18h when detected with immunological method (average optical density: 0.386+/-0.037 vs 0.322+/-0.034, P<0.05). The expression of the TIMP-1 in the AM did not vary when detected with immunological method (P>0.05).

CONCLUSIONSiO2 may affect the expression of MMP-9 and MMP-9 activity in the cultured AM.

Cells, Cultured ; Humans ; Macrophages, Alveolar ; drug effects ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Silicon Dioxide ; toxicity ; Silicosis ; pathology ; Tissue Inhibitor of Metalloproteinase-1 ; metabolism

OBJECTIVETo study the effect of silicosis alveolar macrophages (AM) restimulated by SiO(2) on expression of c-myc oncogene in human embryo lung fibroblasts.

METHODSThe bronchoalveolar lavage of silicosis patients was collected. AMs were divided into 2 groups: (1) SiO(2): AMs were stimulated with SiO(2) (30 microg/ml) for 1, 2, 6, 12, 24 and 36 h; (2) control: treated for the same time without SiO(2). Fibroblasts were cultured with different AMs supernatants for 2 h or 7 h respectively. The expression of c-myc mRNA was determined by RT-PCR and protein by Western Blot.

RESULTSThere was no c-myc expression when fibroblasts were static. The supernatants in the S6 group stimulated expression of c-myc mRNA and protein, with the peak expression at 2 h and 7 h respectively. In the control group, AMs supernatants cultured in different time stimulated expression of c-myc mRNA and protein with the most evident expression at 12 h. The ratios were 0.749 +/- 0.088 and 0.759 +/- 0.101 respectively. Compared with control in the same period, c-myc mRNA and protein expression were significantly stronger treated with the supernatants in which AMs were stimulated for 1 h, 2 h and 6 h by SiO(2) (P < 0.05 or P < 0.01).

CONCLUSIONAMs stimulated with SiO(2) has the ability to induce c-myc oncogene expression in human embryo lung fibroblasts.

Cells, Cultured ; Fibroblasts ; drug effects ; metabolism ; Humans ; Lung ; drug effects ; metabolism ; pathology ; Macrophages, Alveolar ; drug effects ; metabolism ; Proto-Oncogene Proteins c-myc ; genetics ; metabolism ; RNA, Messenger ; genetics ; Silicon Dioxide ; toxicity ; Silicosis ; metabolism ; pathology

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

OBJECTIVETo study the expression and localization of early growth response gene-1 (Egr-1) in macrophages after stimulation by silicon dioxide in vivo and in vitro and to discuss the role of Egr-1 in the development of silicosis.

METHODSThe expression of Egr-1 in animal model of silicosis was analyzed by using immunohistochemistry. Western-blot, immunofluorescence and RT-PCR analysis were used to detect the expression and localization of Egr-1 protein and the dynamic changes of Egr-1 mRNA in cultured macrophages RAW264.7, after stimulation by silicon dioxide.

RESULTSIn animal model with induced silicosis, there was an increased expression of Egr-1 in pulmonary macrophages. The expression levels peaked at the 14th day. In vitro, the transcription of Egr-1 increased in RAW264.7 macrophages during 15 to 240 minutes after the administration of silicon dioxide. The response peaked at 15 minutes and diminished to a minimal level at 480 minutes. Nuclear translocation was most apparent at 60 minutes, lasted till 120 minutes and diminished gradually. During the period from 60 to 120 minutes, the expression of Egr-1 protein also reached a peak.

CONCLUSIONSSilicon dioxide can activate the nuclear transcription factor Egr-1 in vivo and in vitro in macrophages. Egr-1 may thus play an important pathogenetic role in the development of silicosis.

Animals ; Blotting, Western ; Cell Line ; DNA-Binding Proteins ; genetics ; metabolism ; Early Growth Response Protein 1 ; Gene Expression Regulation ; drug effects ; Immediate-Early Proteins ; Immunohistochemistry ; Lung ; drug effects ; metabolism ; pathology ; Macrophages ; drug effects ; metabolism ; Macrophages, Alveolar ; drug effects ; metabolism ; pathology ; Male ; RNA, Messenger ; drug effects ; genetics ; metabolism ; Rats ; Rats, Wistar ; Reverse Transcriptase Polymerase Chain Reaction ; Silicon Dioxide ; pharmacology ; Transcription Factors ; genetics ; metabolism

OBJECTIVETo investigate the role of oxidative stress in the endoplasmic reticulum stress-induced apoptosis of alveolar macrophages triggered by quartz dust.

METHODSSeventy-two healthy adult Wistar rats were randomly divided into control group, quartz dust group, quartz dust plus N-acetyl cysteine (NAC) group, and NAC group, with 18 rats in each group. One milliliter of sterile saline (for the control and NAC groups) or 1 ml of saline with 5%ultrafine quartz dust (for dust group and dust plus NAC group) was given to each rat by non-exposed endotracheal infusion. From the second day after dust infusion, rats in dust plus NAC group and NAC group received intragastric administration of NAC (100 mg/kg). In each week, the treatment with NAC lasted for 5 consecutive days, followed by 2 days' interval. For each group, 6 rats were randomly selected on the 14th, 28th, or 56th day after dust exposure; they were sacrificed by bloodletting from the femoral artery, and the lungs were collected. Bronchoalveolar lavage fluid was collected to separate macrophages. The protein expression of caspase-12 in alveolar macrophages, the apoptosis rate and reactive oxygen species (ROS) content of alveolar macrophages, and the protein carbonyl content of alveolar macrophages were determined by Western blot, flow cytometry, and colorimetry, respectively.

RESULTSIncreased protein expression of caspase-12, apoptosis rate, and content of ROS and protein carbonyl were discovered on the 14th day in the dust group, in comparison with the control group (P < 0.05), and the increase lasted till the 28th and 56th days. (P < 0.05). Compared with the dust group, the dust plus NAC group showed significant decreases in the content of ROS on the 14th, 28th, and 56th days (P < 0.05), significant decreases in the content of protein carbonyl on the 28th and 56th days (P < 0.05), and significant decreases in the protein expression of caspase-12 and apoptosis rate (P < 0.05).

CONCLUSIONOxidative stress is potentially involved in the endoplasmic reticulum stress-induced apoptosis of alveolar macrophages triggered by quartz dust. Oxidative damage of protein in the endoplasmic reticulum may play an important role in the process.

Animals ; Caspase 12 ; metabolism ; Dust ; Endoplasmic Reticulum Stress ; drug effects ; Macrophages, Alveolar ; drug effects ; pathology ; Male ; Oxidative Stress ; drug effects ; Protein Carbonylation ; Quartz ; toxicity ; Rats ; Rats, Wistar ; Reactive Oxygen Species ; metabolism