OBJECTIVETo evaluate the effect of water channel aquaporin 4 (AQP4) on bleomycin-induced lung fibrosis in mice.

METHODSIn wild type and AQP4 gene knockout (AQP4-/-) mice, lung fibrosis was induced by injection of bleomycin (3 mg/kg) into the trachea and saline injection was used as a control. At d3, 7, 14, 28 after bleomycin-treatment, mice were randomly sacrificed in batch and the lung coefficient was determined. Serum levels of TGF-β1 and TNF-α were measured by ELISA and hydroxyproline contents in lung tissue were determined by Alkaline hydrolysis method. H-E staining and Masson's staining were performed to examine the pathological changes of lung tissues after bleomycin-treatment.

RESULTSOn d14 after bleomycin-treatment, the lung coefficients in wild type mice and AQP4-/- mice were 1.9-fold (12.69 ± 6.05 vs 6.80 ± 0.82, q=4.204, P<0.05) and 2.3-fold (14.05 ± 5.82 vs 6.05± 0.58, q=5.172, P<0.01) of that in control, respectively, but no significant difference was found between wild type and AQP4-/- mice in the lung coefficient value (P>0.05). The hydroxyproline contents in the lung increased after bleomycin-treatment; on d28, the lung hydroxyproline contents in wild type and in AQP4-/- mice were 1.55-fold (0.85 ± 0.22 g/mg vs 0.55 ± 0.14 μg/mg, q=4.313, P<0.05) and 1.4-fold (0.84 ± 0.13 μg/mg vs 0.60 ± 0.14μg/mg, q=4.595，P<0.05) of that in control, respectively, but no significant difference was noticed between wild type and AQP4-/- mice in lung hydroxyproline contents. There was a tendency that serum TGF-β1 and TNF-α levels increased in bleomycin-treated mice, but no significant difference was found between wild type and AQP4-/- mice. AQP4-knockout showed no effects on pathological changes of lung tissues with H-E staining and Masson's staining in mice with bleomycin-induced lung fibrosis.

CONCLUSIONAQP4 might not be involved in bleomycin-induced lung fibrosis in mice.

Animals ; Aquaporin 4 ; genetics ; Bleomycin ; toxicity ; Male ; Mice ; Mice, Knockout ; Pulmonary Fibrosis ; chemically induced ; genetics

OBJECTIVETo investigate the sensitivity to bleomycin (BLM) in peripheral blood lymphocytes (PBL) among coke-oven workers.

METHODSNinty-four coke-oven workers with exposure to a high level of polycyclic aromatic hydrocarbons and 64 non-coke-oven workers (control) were recruited into this study. PBL was challenged by 8 microg/ml BLM, a known carcinogen, to induce certain amount of DNA damage, the difference of olive tail moment (TM) measured by comet assay before and after BLM treatment reflected the sensitivity towards mutagens.

RESULTSThe distribution of age, sex, and prevalence of smoking and drinking were not significantly different between these two groups. The geometric mean of urinary 1-hydroxypyrene (1-OHP) was significantly higher in coke-oven workers than in controls (9.0 versus 1.5 microg/L, t = -9.317, P < 0.01). The coke-oven workers showed significantly higher sensitivity to BLM than controls (17.7 versus 14.9, t = -2.583, P = 0.01). A large inter-group difference in sensitivity to BLM was observed in both controls and coke-oven workers. Stratification analysis revealed the significant association between high 1-OHP level (> 9.0 microg/L) and increased sensitivity to BLM (F = 4.001, P = 0.05) among coke-oven workers. Smoking subjects showed a significant higher value of sensitivity than nonsmokers in controls but not in coke-oven workers. No significant difference was observed between age, drinking status, coking history or external exposure class and BLM sensitivity.

CONCLUSIONExposure to coke oven emission could increase the sensitivity to mutagens, which might be a reason of high incidence of lung cancer among coke-oven workers.

Adult ; Benzo(a)pyrene ; toxicity ; Bleomycin ; toxicity ; Coke ; Comet Assay ; DNA Damage ; DNA Repair ; Female ; Humans ; Lymphocytes ; drug effects ; Male ; Middle Aged ; Mutagens ; toxicity ; Occupational Exposure

OBJECTIVETo observe the influence of 1.8 GHz microwave (MW) specific absorption rate (SAR, 3 W/kg) on human lymphocytes DNA damage induced by 4 chemical mutagens [mitomycin C (MMC), bleomycin (BLM), methyl methanesulfonate (MMS), and 4-nitroquinoline 1-oxide (4NQO)].

METHODSComet assay in vitro was used to detect human lymphocyte DNA damage induced by 1.8 GHz MW, 4 chemical mutagens, and MW plus 4 chemicals 0 h and 21 h respectively after exposure. The time exposed to MW or mutagens was 2 h or 3 h respectively. The results were showed by tail length (TL) and tail moment (TM).

RESULTSThe difference of DNA damage between MW group and control group was not statistically significant (P > 0.05). DNA damages in MW plus MMC groups and MW plus 4NQO groups were significantly greater than those in the corresponding concentrations of MMC groups and 4NQO groups (P < 0.01 or P < 0.05). However, MW did not enhance DNA damage induced by MMS and BLM (P > 0.05).

CONCLUSIONExposure to 1.8 GHz (SAR, 3 W/kg) microwave may not induce human lymphocyte DNA damage, but could enhance DNA damage induced by MMC and 4NQO.

4-Nitroquinoline-1-oxide ; toxicity ; Adult ; Bleomycin ; toxicity ; Cells, Cultured ; Comet Assay ; DNA ; drug effects ; DNA Damage ; Humans ; Lymphocytes ; drug effects ; radiation effects ; Male ; Methyl Methanesulfonate ; toxicity ; Microwaves ; adverse effects ; Mitomycin ; toxicity ; Mutagens ; toxicity

OBJECTIVETo observe the ultrastructures of rat alveolar type II cells and change of composition of phospholipid(PL) and content of protein in pulmonary surfactant(PS), to investigate the relation between change in composition of PL and activity of alveolar type II cells.

METHODSThe rats lung injury models were made by intratracheally instilling bleomycin(BLM) (4 mg/ml, 5 mg/kg). 28 rats were divided into four groups: 3-day group, 7-day group, 14-day group and 28-day group. Preparations of each group were stained histochemically and examined by electron microscope, content of PL in BALF, composition of PL and content of protein of each group were determined respectively.

RESULTS(1) Rats lungs in experimental groups were found that PS lost continuously, appeared homogenous and chorionic, dropped in the pulmonary alveolies. 3-day group was more apparent. Ruthenium red attaching on pulmonary surfactant was thicker in 3-day group, and the colour deeper, no difference in 7-day group and 14-day group, thinner in 28-day group. Content of PL in PS of BALF was increasing. Content of phosphatidylglycerol(PG) increased in 3-day group, decreased in 7-day, 14-day and 28-day group. The change of content of phosphatidylinositol(PI) was reversed. (2) Alveolar type II cells degenerated, necrotized, even disintegrated in 3-day group and 7-day group. 3-day group was more apparent. Proliferations of alveolar type II cells were found in each group, 7-day group was more apparent. We found that type II cells transformed to type I cells in 14-day group, extended and attached on bare basement membrane. Content of protein in PS was the highest in 3-day group, almost equal to the content of the control group in 28-day group.

CONCLUSIONMorphologic change and alternation of quality and quantity of PS after bleomycin-induced pulmonary injures specifically reflect the activity of alveolar type II cells. Measuring content of PL in BALF is one of simple and feasible method judging activity of alveolar type II cells when lungs of the rats are injured early by bleomycin.

Animals ; Antibiotics, Antineoplastic ; toxicity ; Bleomycin ; toxicity ; Bronchoalveolar Lavage Fluid ; chemistry ; Lung ; drug effects ; pathology ; ultrastructure ; Pulmonary Alveoli ; chemistry ; Pulmonary Surfactants ; analysis ; Rats

BACKGROUND: Macrophages are involved in the pathogenesis of idiopathic pulmonary fibrosis, partially by activating lung fibroblasts. However, how macrophages communicate with lung fibroblasts is largely unexplored. Exosomes can mediate intercellular communication, whereas its role in lung fibrogenesis is unclear. Here we aim to investigate whether exosomes can mediate the crosstalk between macrophages and lung fibroblasts and subsequently induce fibrosis. METHODS: In vivo, bleomycin (BLM)-induced lung fibrosis model was established and macrophages infiltration was examined. The effects of GW4869, an exosomes inhibitor, on lung fibrosis were assessed. Moreover, macrophage exosomes were injected into mice to observe its pro-fibrotic effects. In vitro, exosomes derived from angiotensin II (Ang II)-stimulated macrophages were collected. Then, lung fibroblasts were treated with the exosomes. Twenty-four hours later, protein levels of α-collagen I, angiotensin II type 1 receptor (AT1R), transforming growth factor-β (TGF-β), and phospho-Smad2/3 (p-Smad2/3) in lung fibroblasts were examined. The Student's t test or analysis of variance were used for statistical analysis. RESULTS: In vivo, BLM-treated mice showed enhanced infiltration of macrophages, increased fibrotic alterations, and higher levels of Ang II and AT1R. GW4869 attenuated BLM-induced pulmonary fibrosis. Mice with exosomes injection showed fibrotic features with higher levels of Ang II and AT1R, which was reversed by irbesartan. In vitro, we found that macrophages secreted a great number of exosomes. The exosomes were taken by fibroblasts and resulted in higher levels of AT1R (0.22 ± 0.02 vs. 0.07 ± 0.02, t = 8.66, P = 0.001), TGF-β (0.54 ± 0.05 vs. 0.09 ± 0.06, t = 10.00, P < 0.001), p-Smad2/3 (0.58 ± 0.06 vs. 0.07 ± 0.03, t = 12.86, P < 0.001) and α-collagen I (0.27 ± 0.02 vs. 0.16 ± 0.01, t = 7.01, P = 0.002), and increased Ang II secretion (62.27 ± 7.32 vs. 9.56 ± 1.68, t = 12.16, P < 0.001). Interestingly, Ang II increased the number of macrophage exosomes, and the protein levels of Alix (1.45 ± 0.15 vs. 1.00 ± 0.10, t = 4.32, P = 0.012), AT1R (4.05 ± 0.64 vs. 1.00 ± 0.09, t = 8.17, P = 0.001), and glyceraldehyde-3-phosphate dehydrogenase (2.13 ± 0.36 vs. 1.00 ± 0.10, t = 5.28, P = 0.006) were increased in exosomes secreted by the same number of macrophages, indicating a positive loop between Ang II and exosomes production. CONCLUSIONS Exosomes mediate intercellular communication between macrophages and fibroblasts plays an important role in BLM-induced pulmonary fibrosis.
Angiotensin II ; Animals ; Bleomycin/toxicity* ; Exosomes ; Fibroblasts ; Lung ; Macrophages ; Mice ; Mice, Inbred C57BL ; Pulmonary Fibrosis/chemically induced* ; Receptor, Angiotensin, Type 1

OBJECTIVETo observe the changes of matrix metalloproteinases (MMPs) activities in pulmonary fibrosis rats.

METHODSEighty male SD rats were randomly divided into sham group (n = 40) and bleomycin group (BLM, n = 40), in which SD rats were injected with a single intratracheal dose of sham saline or bleomycin respectively. On day 1, 3, 7, 14, and 28 following bleomycin or saline instillation, rats were randomly killed, and serum from abdominal aorta, alveolar fluid from the bronchoalveolar lavage, and the lung homogenate were collected and then stored at -80 degrees C. MMPs activity was determined by zymography.

RESULTSCompared with sham group, the levels of MMP-9 in all samples were augmented. MMP-9 activities in the serum were highest on day 3 than those on day 1 and day 7, and in lung tissue homogenate were highest on day 7; however, no significant differences were found between BLM group and sham group on day 14 and day 28; and that of bronchoalveolar lavage fluid (BALF) was highest on day 7 than those on day 1 and day 14, while no significant difference existed between BLM group and sham group on day 28. Serum MMP-2 level did not change from day 1 to day 28, while the level of BALF MMP-2 began to increase after day 14, even on day 28. Lung tissue homogenate MMP-2 level began to increase early on day 3 and continued to day 28.

CONCLUSIONThe sources and effects of MMP-2 and MMP-9 differ in BLM-induced rat pulmonary fibrosis.

Animals ; Bleomycin ; toxicity ; Disease Models, Animal ; Male ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Pulmonary Fibrosis ; chemically induced ; enzymology ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To study the changes in mRNA and long non-coding RNA (lncRNA) expression profiles in a mouse model of bleomycin-induced lung fibrosis and identify lung fibrosis-related mRNA for coding-noncoding coexpression (CNC) bioinformatics analysis of the differential lncRNAs. METHODS: Lung fibrosis was induced by intratracheal injection of bleomycin in 10 C57BL/6 mice and another 10 mice with intratracheal injection of saline served as the control group. Lung tissues were harvested from the mice at 14 days after the injections and lung fibrosis was assessed using Masson and HE staining. LncRNA chip technology was used to screen the differentially expressed mRNAs and lncRNAs in mice with lung fibrosis, and GO and KEGG pathway analyses of the differential mRNAs were performed using NCBI database and UCSC database to identify possible fibrosis-related mRNAs, which were validated by qRT-PCR to construct a coding and non-coding co- expression network with the differential lncRNAs. RESULTS: Compared with the control mice, the mice with intratracheal injection of bleomycin showed obvious lung fibrosis. The results of gene chip analysis showed that 127 mRNAs were upregulated and 184 mRNAs were down-regulated in the model group as compared with the control group. GO and pathway analysis suggested that the differentially expressed genes participated mainly in immune response, cell differentiation, and cytoskeletons; the involved signal pathways were associated mainly with cytokine and cytokine receptor interaction and chemokine signal transduction. Bioinformatics analysis identified a significant coexpression network between the fibrosisrelated mRNA and the differentially expressed lncRNA. CONCLUSIONS In mice with lung fibrosis, the differential expressions of fibrosis-related mRNAs in the lung tissues are closely correlated with the co- expressions of a large number of differential lncRNAs, which points to a new direction for investigation of the pathogenesis of pulmonary fibrosis.
Animals ; Bleomycin/toxicity* ; Gene Expression Profiling ; Gene Regulatory Networks ; Mice ; Mice, Inbred C57BL ; Pulmonary Fibrosis/genetics* ; RNA, Long Noncoding/genetics* ; RNA, Messenger/genetics*

Ivermectin is a US Food and Drug Administration (FDA)-approved antiparasitic agent with antiviral and anti-inflammatory properties. Although recent studies reported the possible anti-inflammatory activity of ivermectin in respiratory injuries, its potential therapeutic effect on pulmonary fibrosis (PF) has not been investigated. This study aimed to explore the ability of ivermectin (0.6 mg/kg) to alleviate bleomycin-induced biochemical derangements and histological changes in an experimental PF rat model. This can provide the means to validate the clinical utility of ivermectin as a treatment option for idiopathic PF. The results showed that ivermectin mitigated the bleomycin-evoked pulmonary injury, as manifested by the reduced infiltration of inflammatory cells, as well as decreased the inflammation and fibrosis scores. Intriguingly, ivermectin decreased collagen fiber deposition and suppressed transforming growth factor-‍β1 (TGF-‍β1) and fibronectin protein expression, highlighting its anti-fibrotic activity. This study revealed for the first time that ivermectin can suppress the nucleotide-binding oligomerization domain (NOD)‍-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome, as manifested by the reduced gene expression of NLRP3 and the apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), with a subsequent decline in the interleukin‍-‍1β (IL‍-‍1β) level. In addition, ivermectin inhibited the expression of intracellular nuclear factor-‍κB (NF‍-‍κB) and hypoxia‑inducible factor‑1α (HIF‍-‍1α) proteins along with lowering the oxidative stress and apoptotic markers. Altogether, this study revealed that ivermectin could ameliorate pulmonary inflammation and fibrosis induced by bleomycin. These beneficial effects were mediated, at least partly, via the downregulation of TGF-‍β1 and fibronectin, as well as the suppression of NLRP3 inflammasome through modulating the expression of HIF‑1α and NF-‍κB.
Animals ; Rats ; Anti-Inflammatory Agents ; Bleomycin/toxicity* ; Fibronectins/metabolism* ; Fibrosis ; Inflammasomes/metabolism* ; Ivermectin/adverse effects* ; NF-kappa B/metabolism* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Pulmonary Fibrosis/drug therapy*

OBJECTIVETo observe the effects of three different doses of polydatin (PD) on pulmonary interstitial fibrosis in rats induced by bleomycin.

METHODOne hundred and twenty-nine healthy Sprague-Dawley rats three months old, were randomly divided into six groups. Group A: normal control group; group B: model group treated with bleomycin (pretreatment with saline 1 mL x kg(-1) intraperitoneally before bleomycin); group C: PD 10 mg x kg(-1) (pretreatment with PD 10 mg x kg(-1) intraperitoneally before bleomycin); group D: PD 20 mg x kg(-1) (pretreatment with PD 20 mg x kg(-1) intraperitoneally before bleomycin); group E: PD 40 mg x kg(-1) (pretreatment with PD 40 mg x kg(-1) intraperitoneally before bleomycin), group F: dexamethason (DXM) treated group (pretreatment with saline 1 mL x kg(-1) intraperitoneally before bleomycin and then with DXM 1 mg x kg(-1) x d(-1)). At day 3, 7, 14, 28 after injection of bleomycin, eight rats in each group were randomly chosen to be killed. The right lungs of dead rats were removed and appropriately processed for hematoxylin and eosin (H&E) stain, histologically observed under light microscope. The hydroxyproline content and the PLA2 activity in pulmonary homogenate were measured with alkaline hydrolysis assay and acid modified microtitrimetic method. The levels of leukotriene C4 (LTC4), prostaglandin E2 (PGE2), transforming growth factor-beta1 (TGF-beta1) in bronchoalveolar lavage fluid (BALF) were measured with enzyme-linked immunosorbent assay (ELISA).

RESULTAt day 3, 7, 14, 28 after intratracheal instillation of bleomycin in rats of group B, the PLA2 activity in lung homogenate and the levels of its metabolic products PGE2, LTC4 as well as TGF-beta1 in BALF increased significantly compared with those in group A (P < 0.01). And lung hydroxyproline concentration began to grow up markedly at day 7 compared with those in group A (P < 0.05), reaching its maximum at day 28. Compared with group B, three different doses of PD and DXM significantly reduced the activity of the PLA2 and hydroxyproline concentration in lung homogenate as well as the levels of PGE2, LTC4, TGF-beta1 in BALF at various periods (P < 0.05). There was statistically significant difference between three different doses of PD groups (P < 0.05). And the group E (PD 40 mg x kg(-1)) was lower than group D (PD 20 mg x kg(-1)), group D was lower than group C (PD 10 mg x kg(-1)) (respectively, P < 0.01). Group E and DXM group were no significant difference. However, all these observation parameters were higher than the normal level (compared with group A, P < 0.01). Histological studies revealed that it was showed less inflammation and a lower degree of fibrosis in the lungs treated with PD than bleomycin model group.

CONCLUSIONPD has the protective effect on pulmonary interstitial fibrosis. However, it can't completely block the process of pulmonary fibrosis.

Animals ; Bleomycin ; toxicity ; Dinoprostone ; analysis ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Glucosides ; therapeutic use ; Leukotriene C4 ; analysis ; Male ; Phospholipases A2 ; analysis ; Pulmonary Fibrosis ; chemically induced ; drug therapy ; metabolism ; Rats ; Rats, Sprague-Dawley ; Stilbenes ; therapeutic use

OBJECTIVETo explore the relationship between the injury of vascular endothelial cells and formation of lung fibrosis by bleomycin (BLM) in rats.

METHODSThe rats of experimental groups were treated with bleomycin intratracheally to induce pulmonary fibrosis. The expression of vascular endothelial growth factor (VEGF) in pulmonary tissues were analyzed qualitatively and quantitatively by immunohistochemistry and image analysis system.

RESULTS(1) HISTOLOGY: Edema in rat alveoli and alveolar septum, inflammatory cells exudation, degeneration and necrosis of type I and type II alveolar epithelial cells (AETI and AETII), ruptured alveolar basement membrane, as well as swollen vascular endothelial cells and karyopyknosis were observed in 3 d and 7 d after treatment with BLM. AETII proliferation, with more fibroblasts in alveolar septum, and new capillary vessel formation in 7, 14 d, as well as thickened alveolar septum, damaged alveolar structure, and obvious pulmonary tissue fibrosis in 28 d after treatment with BLM were observed. (2) Immunohistochemistry: in normal control, VEGF expressed weakly in pulmonary tissue distributing mainly in AETII, bronchial epithelial cells, alveolar macrophages and leydig's cells. While in bleomycin treated groups, the expression of VEGF increased markedly. The expression in AETII, and pulmonary macrophage were significantly higher than that in control in 3 d to 28 d (P < 0.05, P < 0.01). The rat leydig's cells also had higher expression of VEGF in 7, 14, 28 d (P < 0.05, P < 0.01).

CONCLUSIONThe high expression of VEGF is related to vascular endothelial cells injury which may be one of important factors in the formation of bleomycin-induced pulmonary fibrosis.

Animals ; Bleomycin ; toxicity ; Disease Models, Animal ; Endothelial Cells ; metabolism ; pathology ; Immunohistochemistry ; Lung ; metabolism ; pathology ; Pulmonary Alveoli ; pathology ; Pulmonary Fibrosis ; chemically induced ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley ; Vascular Endothelial Growth Factor A ; metabolism