The aim of this study was to investigate the effects of polarization program on the ability of macrophages to regulate iron metabolism. M1 and M2 macrophages were propagated in vitro from porcine alveolar macrophages 3D4/2 and polarized by cytokines. The 3D4/2 macrophages were treated with 20 ng/mL interferon gamma (IFN-γ) and 10 ng/mL interleukin-4 (IL-4) combined with 10 ng/mL macrophage colony-stimulating factor (M-CSF) to induce polarization to M1 and M2, respectively. After incubation for 24 h, the expression levels of inflammatory factors and iron-metabolism genes were determined using real-time qPCR, Western bot and immunofluorescence. The M1/M2 macrophages culture media supernatant was collected and used to treat porcine intestinal epithelial cells IPEC-J2. The proliferation ability of IPEC-J2 was detected using CCK-8 assay kit. Following exogenous addition of ammonium ferric citrate (FAC) to M1/M2 macrophages, the phagocytic function of macrophages was detected using fluorescein isothiocyanate-dextran (FITC-dextran) and flow cytometry. The results showed that, compared with control, M1 macrophages had higher mRNA levels of iron storage proteins (ferritin heavy and light polypeptide, i.e. FtH and FtL), hepcidin and lipocalin-2, as well as iron content. Moreover, iron enhanced the ability of M1 macrophages to phagocytize FITC-dextran. There was no significant change in these mRNA expression levels in M2 macrophages, but the mRNA expression levels of ferroportin and transferrin receptor were up-regulated. In addition, the conditioned media supernatant from M2 macrophages promoted cell proliferation of IPEC-J2. These findings indicate that M1 macrophages tend to lock iron in the cell and reduce extracellular iron content, thereby inhibiting the proliferation of extracellular bacteria. While M2 macrophages tend to excrete iron, which contributes to the proliferation of surrounding cells and thus promotes tissue repair.
Animals ; Cytokines ; Ferritins ; Iron/metabolism* ; Macrophages/metabolism* ; Macrophages, Alveolar/metabolism* ; Swine

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

OBJECTIVETo study the effect of the cultured supernatant of human silicotic alveolar macrophages (AM) on the expression of the collagen type I in human embryonic lung fibroblasts.

METHODSHuman alveolar macrophages were collected from a silicotic patient by bronchoalveolar lavage and exposed to silicon dioxide for 18 h. Then the cultured supernatant were used to culture human embryonic lung fibroblasts for 6 h, 12 h, 18 h, 24 h, 36 h, 48 h, 72 h. Then detected collagen anabolism and secretion with (3)H-proline detected the expression of the procollagen type I in the fibroblast with immunological method detected the quantity of collagen Type I in FB supernatant with Western blot.

RESULTSThe anabolism and secretion of collagen were increased in cultured supernatant of silicotic AM exposed to SiO(2), Along with the time, the expression of collagen type I increased. In cultured supernatant of silicotic AM exposed to SiO(2), ((3)H-proline: 1096.500 +/- 76.400, 707.000 +/- 62.160, OD: 0.314 +/- 0.011, OD: 14.218 +/- 0.342.

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

Adult ; Cells, Cultured ; Collagen Type I ; metabolism ; Fibroblasts ; metabolism ; Humans ; Lung ; metabolism ; Macrophages, Alveolar ; immunology ; Male ; Silicosis ; immunology

In order to study the signal pathway secreting type Ⅰ interferon in porcine alveolar macrophages (PAMs) infected with porcine circovirus type 2 (PCV2), the protein and the mRNA expression levels of cGAS/STING pathways were analyzed by ELISA, Western blotting and quantitative reverse transcriptase PCR in PAMs infected with PCV2. In addition, the roles of cGAS, STING, TBK1 and NF-κB/P65 in the generation of type I interferon (IFN-I) from PAMs were analyzed by using the cGAS and STING specific siRNA, inhibitors BX795 and BAY 11-7082. The results showed that the expression levels of IFN-I increased significantly at 48 h after infection with PCV2 (P<0.05), the mRNA expression levels of cGAS increased significantly at 48 h and 72 h after infection (P<0.01), the mRNA expression levels of STING increased significantly at 72 h after infection (P<0.01), and the mRNA expression levels of TBK1 and IRF3 increased at 48 h after infection (P<0.01). The protein expression levels of STING, TBK1 and IRF3 in PAMs infected with PCV2 were increased, the content of NF-κB/p65 was decreased, and the nuclear entry of NF-κB/p65 and IRF3 was promoted. After knocking down cGAS or STING expression by siRNA, the expression level of IFN-I was significantly decreased after PCV2 infection for 48 h (P<0.01). BX795 and BAY 11-7082 inhibitors were used to inhibit the expression of IRF3 and NF-κB, the concentration of IFN-I in BX795-treated group was significantly reduced than that of the PCV2 group (P<0.01), while no significant difference was observed between the BAY 11-7028 group and the PCV2 group. The results showed that PAMs infected with PCV2 induced IFN-I secretion through the cGAS/STING/TBK1/IRF3 signaling pathway.
Animals ; Cells, Cultured ; Circovirus ; Interferon Type I/genetics* ; Macrophages, Alveolar/virology* ; Membrane Proteins/metabolism* ; Nucleotidyltransferases/metabolism* ; Signal Transduction ; Swine

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 analyze the expression of different proteins in free silica-induced transdifferentiated rat lung fibroblasts.

METHODSRat lung fibroblasts and alveolar macrophages were cultured. A transdifferentiation model of rat lung fibroblasts was established. Free silica was used as a stimulator for rat lung fibroblasts. Changes in α-SMA were detected by immunohistochemistry and Western blot, respectively. Protein of lung fibroblasts was extracted and analyzed by two-dimensional electrophoresis (2-DE).

RESULTSSix protein spots were identified by mass spectrometry, including glyceraldehyde 3-phosphate-dehydrogenase, peroxiredoxin 5, heterogeneous nuclear ribonucleoprotein A2, transgelin 2, keratin K6 and vimentin.

CONCLUSIONSome proteins are changed in free silica-induced transdifferentiated rat lung fibroblasts.

Animals ; Cell Transdifferentiation ; Electrophoresis, Gel, Two-Dimensional ; Fibroblasts ; metabolism ; Macrophages, Alveolar ; physiology ; Male ; Rats ; Silicon Dioxide ; Silicosis ; etiology

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

OBJECTIVETo investigate the role of calcium activated-potassium channels (KCa) in the injury to rat alveolar macrophages induced by quartz.

METHODSThe experiments were conducted on a rat alveolar macrophage cell line (NR8383) in vitro, where crystal silica (100 üg/ml) and amorphous silica (100 üg/ml) were used as the test substances and the cells without any treatment as negative controls. At first the effects of two kinds of quartz were compared. Then KCa special inhibitors (Paxilline for BK, Tram-34 for IK, Apamin for SK) were added in different doses to the in vitro test system with 100 üg/ml crystal quartz as matrix, to observe the function of such channels. Cell viability, lactate dehydrogenase (LDH), interleukin-1β (IL-1β) and tumor necrosis factor-a (TNF-α) were tested.

RESULTSComparing to the negative control group, cell viability reduced, LDH leakage, IL-1β and TNF-α release increased significantly in the amorphous quartz group, furthermore, the effects by crystal quartz were much more serious than those by amorphous quartz, with a statistical significance (P < 0.01). Comparing to the crystal quartz group, IK blockers (Tram-34) led to increase in cell viability significantly, with a statistical significance (P < 0.01); all the KCa specific blockers (Paxilline, Tram-34, Apamin) could reduce LDH leakage and IL-1β release, with a statistical significance (P < 0.05); meanwhile, BK and IK blockers (Paxilline,Tram-34) were able to reduce TNF-α release,with a statistical significance (P < 0.05).Reduction of IL-1β and TNF-α by Tram-34 was dose-dependent, but not so in the other two blockers.

CONCLUSIONBlocking calcium-activated potassium channels (KCa) could reduce cell membrane damage as well as IL-1β and TNF-α release induced by crystal quartz in the rat alveolar macrophages cell line in vitro, which might serve as a signal in the early regulation of inflammatory responses by quartz.

Animals ; Calcium ; metabolism ; Cell Line ; Interleukin-1beta ; metabolism ; Macrophages, Alveolar ; cytology ; metabolism ; Potassium Channels, Calcium-Activated ; metabolism ; Quartz ; toxicity ; Rats ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo explore the role of superoxide dismutase (SOD) coenzyme in regulation of Fas/FasL signal transduction and apoptosis of alveolar macrophages in pneumoconiosis patients.

METHODS50 male and Han nationality cases, including the dust exposed workers, Phase I, II pneumoconiosis patients confirmed by local pneumoconiosis diagnosis group according to GBZ 70 - 2002 diagnosis standard, who underwent whole lung lavage treatment were chosen as subjects. Their alveolar macrophages (AMs) were collected and purified. The cells were divided into three groups: the untreated group, the Fas/FasL group and the SOD group. 5 x 10(6) purified AMs were added into incubating bottles containing DMEM for 2 hours for purifying, added with SOD coenzyme and other block reagents separately, and then incubated for 24 hours in CO(2) incubation. The cells were harvested and lysed. Western-blot were used to analyze the expressions of Fas, FasL, Caspases-8 and Caspases-3. Software of Quantity One 7.0 was used to analyze the relative quantity of Fas, FasL, Caspase-8 and Caspase-3. TUNEL and DNA fragment analysis were used to analyze AMs apoptosis.

RESULTSThe apoptosis index in SOD coenzyme group (9.50 +/- 2.76)% and Fas/FasL group (14.01 +/- 2.56)% was significantly lower than that of in untreated group (19.18 +/- 2.83)% (P < 0.05). The catachrestic DNA ladder appeared in untreated group, was looming in Fas/FasL group, and was not found in the SOD group. The expressions of Fas, FasL, Caspase-8 and Caspase-3 of phase I and II in SOD group were higher than in the other two groups (P < 0.05). There was no significant difference in the expression of Fas, FasL, Caspase-8 and Caspase-3 among different phases of pneumoconiosis (P > 0.05).

CONCLUSIONSOD coenzyme can effectively regulate Fas/FasL signal transduction and block AMs apoptosis.

Adult ; Apoptosis ; Cells, Cultured ; Fas Ligand Protein ; metabolism ; Humans ; Macrophages, Alveolar ; metabolism ; pathology ; Male ; Middle Aged ; Pneumoconiosis ; metabolism ; pathology ; Signal Transduction ; Superoxide Dismutase ; metabolism ; fas Receptor ; 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